Table of contents

It is our great pleasure to welcome you to the International Conference on Nanomaterials: Science, Engineering and Technology (ICoNSET) 2019, which was held on August 5-6, 2019 at the Rainbow Paradise Beach Resort, Penang, Malaysia.

With 'Nanomaterials in Science, Engineering and Technology for Sustainability' as its main theme, ICoNSET 2019 served as a platform for academicians, researchers, scientist, practitioners and students to generate and present new ideas in related fields. The conference also aimed to gather intellectuals from various fields to share the knowledge and discuss the recent trends and current issues in the fields of Nanomaterials, as well as Engineering and Sciences. Aside from that, the conference also served as a great opportunity to initiate a research collaboration network among participants with similar research interests from around the world.

The proceedings present a selection of the papers submitted to the conference from various universities, research institutes, and industries. All of the papers were subjected to peer-review by conference committee members and qualified reviewers. The papers selected for publishing in the proceedings depended on their quality and their relevance to the conference. The proceedings tend to present to the readers the recent advances in the field of Nanomaterials Synthesis and Applications, Nanoscale Electronics, Nanotech for Energy and Environment, Graphene Based-Materials, Advanced Materials, and various related areas.

We would like to express our utmost gratitude to all the authors who have contributed to the proceedings and also to the reviewers, keynote speakers, chairs, sponsors and all the conference participants for their supports to ICoNSET 2019.

ICoNSET 2019 Organizing Committee

August 31, 2019

List of Patron, Conference Chair, Conference Deputy Chair, Secretary I, Secretary II, Bursary 1, Bursary 1I, Bursary 1II, Promotion and Publicity, Registration and Program Book, Sponsorship, Logistic, Conference kits/certificate/gifts, Publication and Protocol are available in this pdf.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Utilizing renewable resource such as palm oleic acid and convert into epoxide has attracted the interest of many researchers around the world. This paper aimed to study the effects of hydrogen peroxide, formic acid and water on the ring opening of epoxide groups using in situ generated performic acid. The results showed that the cleavage of oxirane rings was the most affected by hydrogen peroxide, followed by formic acid which led to the formation of diol and a-glycol as side products. The FTIR results indicated that the absorption band of hydroxyl group (O-H) was observed at 3100-3600 cm-1 in placement of the epoxy ring group (C-O-C) at 1210 – 1250 cm-1. It is imperative to minimize process losses via ring-opening in order to achieve good yields and high peroxide values of the epoxidized vegetable oil.

Huge usage of Polylactic Acid (PLA) has contributed to the high wastes which mainly come from the worn parts. Recycling of the wastes is seen to be a permissible solution to reduce the quantity of wastes in the landfills. This work aims to compare the mechanical properties of virgin and recycled PLA. The recycled material is collected from the waste produces from the injection molding process. The mechanical testing samples for both virgin and recycled materials are prepared using an injection molding process. The results show that the mechanical properties of recycled PLA lower than the virgin PLA. The tensile strength of recycled PLA decreases by 11% as compared to virgin PLA. On the other hand, TRS is also observed drop by 5% for recycled PLA compared to virgin PLA. A similar trend is found in the impact strength and hardness of properties where its impact strength drops by 50% of recycled PLA. For hardness property, it is noted that the hardness decreases by 4% of the recycled PLA. The decreasing value of the mechanical properties is due to thermal degradation of the PLA molecular chain during the injection molding process which has consequently affected the mechanical properties of the recycled PLA.

In Malaysia, traditional folks call Gynura procumbens as Sambung nyawa or translated as longevity life. The name given might be because of the claim made by them that the leaves extracts seems to be valuable and possesses high theuraphatic potential treatment of various diseases. Extraction of the leaves have been conducted by many researchers to identify the properties for antidiabetic/antihyperglygemic, antihypertensive, antimicrobial, antioxidant, antiimflammatory, antiulcer, anticancer, antiherpes and immunomodulatory. Extracts have been obtained using different solvent. Four alcoholic extracts and one water extract were studied separately. Soxhlet extraction was conducted in the following manner: plant material (3.0 g) was placed in the Soxhlet apparatus. Extraction process was carried out for three hours using 99.9% ethanol, methanol and water as a solvent (250 mL) until the solvent discoloration (3 hours). Yield of extraction techniques was determined by evaporating the solvent under vacuum using rotary evaporator. Previous research on solvent extraction of Gynura procumbens were also compared to whereby the methanol extract obtained by other researcher was 12.2%, ethanol extract with 14.73% and 27.83%. There is also one study extracting Gynura procumbens extracts via water, however the yield is not mentioned. High performance liquid chromatography (HPLC) coupled with ultra violet (UV) detector has been used for the separation and quantification of kaempferol from the Gynura procumbens leaves extract. Reversed phase high performance liquid chromatography separation was performed, using 0.1% phosphoric acid:acetonitrile as eluent in mobile phase. Our results confirm previous reports concerning the presence of several flavonoids.

This study assessed the applicability of normalized method in predicting the stress-strain curve at the strain softening phase. The methodology is based on standard test and easily replicable which is conventional triaxial test. The soil sample from Kuala Terengganu, Malaysia was taken for the test. The drained triaxial test was conducted on four samples with various effective stresses (50, 100, 200 and 300kPa). The results showed that the soil is classified as silty clay with high plasticity. Based from the results, the stress-strain curves indicate strain softening clearly. The normalized method is applied in this study. It is based from Rotational Multiple Yield Surface Framework (RMYSF). However, RMYSF is applied to predict the stress-strain curves for unsaturated soil and limited to strain hardening only. Extension work is conducted to the existing method by predicting the strain softening phase for saturated soil. It can be concluded that normalized method is successfully predicted the strain softening phase of the soil. The main advantage of this method is that it can be applied to predict the soil strength parameter for various effective stresses without having to conduct many tests. Therefore, this method will help to cut the time and cost of testing effectively.

Aluminium sulphate Al2(SO4)3 known as alum is commonly added chemical in coagulation-flocculation process in water treatment plants. Despite of its effectiveness in treating the water, it produces high volume of residual alum sludge to be discarded to sludge lagoon. Therefore, sludge disposal is one of the main drawbacks in water treatment plants as it requires large footprints to store the residual sludge before being dumped at landfills. The sludge still contains high concentrations of aluminium that can be recovered for further use. Acidification process using sulphuric acid is investigated in this study to recover the aluminium from sludge. Different dosage of sulphuric acid ranges at 0.45 – 1.80M at constant weight of alum sludge at 300g were analysed to obtain the maximum percentages of aluminium recovery. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to analyse the recovered aluminium concentration. Besides the element of aluminium, other elements such as Ferum (Fe), Calcium (Ca) and Potassium (K) were also recovered through the acidification process. It was found that element of aluminium shows the highest concentration. The optimum recovery of aluminium was attained at alum sludge 300g and dosage of 1.35M sulphuric acid in which the recovery ratio at up to 98%. This shows that the aluminium present at high concentration in the sludge and if the sludge is dumped at landfills, the remaining aluminium will affect the environment. Furthermore, it is recommended that the recovered aluminium from water treatment sludge has the potential to be an alternative coagulant element in water treatment process.

Construction site safety is a vital issue in construction safety management. The causes of accidents in the construction industry, among others are due to individual behaviour, complicated work-site surroundings and inadequate safety supervision at the construction site. The case study, namely Pan-Borneo Highway (PBH), was initiated through the Economic Transformation Programme to transform Malaysia into a high-income nation. The PBH is an option travel mode highway alongside Borneo road linking the states of Sarawak and Sabah with Brunei. The iconic project started from Sematan, Sarawak to Tawau, Sabah. This paper aimed to evaluate the current safety management practices on PBH construction sites in Kuching, Sarawak, as well as to emphasise the significance of road construction safety supervision. Questionnaires were distributed to 30 respondents, and the survey responses were analysed using Statistical Package for Social Science (SPSS) software. The result suggested that the most important safety practices are the provision of Personal Protective Equipment (PPE), followed by accident reporting and maintenance report and provision of safety policy. Proper safety management on the construction site can minimise accidents and protect all parties involved in the construction industry.

Microwave absorber able to inhibit the reflection of electromagnetic radiation. Microwave absorbers are used in an anechoic chamber along with its wall, ceiling and floor for the electromagnetic compatibility (EMC) and electromagnetic interference (EMI) evaluation. This research is to develop a flat shape of biomass absorbers using an agricultural material. The main material used in constructing the flat absorber is a natural bamboo. The flat shaped absorber is chosen because it could reach the standard set in the specified industry and suitable to be used in the microwave frequency range. Cylindrical bamboo with different radius have been used for this study. Radius 0.2 cm for Design 1 and 1 cm for Design 2. The range of frequencies are set in the range from 1 GHz to 12 GHz. The result of microwave absorber is analyzed for its absorption performance. The generated result from the technique shows that the flat stick bamboo microwave absorber operates the best in Design 2 with 34.9% of absorption performance compared with Design 1. The overall results in different angles for both designs are analyze and compared.

Nowadays, the resources of roofing materials are abundant, which are the essential materials to build houses. It is of great significance to develop the roofing material with absorbing function for shielding electromagnetic radiation. This study is conducted to design a corrugated bamboo roofing microwave absorber that can absorb electromagnetic wave for frequencies 1 to 12 GHz. Three types of roofing bamboo with different designs namely Model A, Model B and Model C has been developed. The size of all types of proposed roofing bamboo is 60 cm width x 60 cm in length. The design is simulated using Computer Simulation Technology (CST) Microwave Studio software. The arch method is used to analyse microwave absorber performance. It contains of a wooden structure in the shape of semi-circular for enabling the proper positioning towards transmitting and receiving the two horn antennas. Bamboo can be used as an absorbent material. The expected result for bamboo roofing microwave absorber is to get a high performance of microwave absorption which is above 20 dB. The third model or Model C has recorded the highest value of an absorption level.

Plastic have become a major problem in solid waste management due to its inability to degrade when they are disposed at landfill site. Approximately 0.80 kg/capita to 1.9 kg/capita of municipal solid waste is generated daily in Malaysia, which is expected to increase annually. Cracking of rigid pavement is the phenomenon where the pavement fails under repetitive loading by a load smaller than the load that can cause failure in single application. Other than that, decrements of the flexural strength due to the lower tensile strength can cause the joint spalling. The larger the load, the smaller will be the number of repetition to cause cracks. In this study paper presents the effect of Polyethene terephthalate (PET) road barrier waste as alternative addition in concrete grade C40 for rigid pavement. The material was obtained from Jabatan Kerja Raya(JKR) Seberang Perai Tengah and it need through cutting process to become fiber with range size about 12mm15mm length and 3mm-5mm width before to be addition into concrete. Four types of concrete mixes with different percentages of PET road barrier fibers which are 0%, 1%, 2% and 3%. Each specimen consist of six cube samples and one beam. The six cubes represent sample at 3 days, 7 days and 28 days. The beam sized 150mm x 150mm x 750mm was only tested on 28 days of curing. The result obtained on the compressive test, 2% of additive PET road barrier in concrete shows the highest result compare to the 0% and 1% additive. Compression test result shows 2% of PET road barrier waste fibers as the optimum percentage of PET road barrier additive with the maximum load of 42.13 MPa.

The main purpose of this study is to identify the optimum multistage compression strategies for minimising the compression and intercooler power requirements for pure CO₂ stream. An analytical model based on thermodynamics principles is developed and applied to determine the power requirements for various compression strategies for pure CO₂ stream. The compression options examined include conventional multistage integrally geared centrifugal compressors (option A), supersonic shockwave compressors (option B) and multistage compression combined with subcritical (option C) and supercritical liquefaction (option D) and pumping. In the case of determining the power demand for inter-stage cooling and liquefaction, a thermodynamic model based on Carnot refrigeration cycle is applied. From the previous study by [1], the power demand for inter-stage cooling duty was assumed to have been neglected. However, based on the present study, the inter-stage cooling duty is predicted to be significantly higher and contributes approximately 30% of the total power requirement for compression options A, C and D, while reaches 58% when applied to option B. It is also found that compression option C can offer higher efficiency than other compression strategies, while supercritical liquefaction efficiency is only marginally higher than that in the compression option A.

This research aimed to determine the suitability of citrus fruit peel waste namely as Citrus Aurantiifolia (key lime) and Citrus Microcarpa (kasturi lime) to act as a natural coagulant for water turbidity removal. The performance of these two coagulants was assessed in terms of turbidity removal using jar test experiments for synthetic low turbid water. The results indicated that the optimum dosage and turbidity removal for Citrus Microcarpa and Citrus Aurantiifolia was found at 30 mg/l with 75.6% turbidity removal and 60 mg/l with 74 % turbidity removal, respectively. Citrus Aurantiifolia showed higher removal efficiency as compared to Citrus Microcarpa. The study demonstrated that both citrus fruit peel waste has the potential to be use as a substitute for chemical based coagulant for a future alternative in water treatment.

A comprehensive study of rock properties is crucial to investigate and characterize the behavior of rock when it undergoes multiple loading and stresses. The properties of rocks are heavily influenced by weathering grade and the composition of minerals which indicates the hardness, swelling potential and abrasiveness, therefore give an effect on the strength and the durability of rocks. The interaction between mineralogy and engineering properties are significantly important for the engineer to fully understand the behavior of mudrock for further application especially in Malaysia. Selected weathered mudrocks from Bukit Kukus Kedah, a part of Semanggol formation were characterized for physical, mechanical and mineral properties. The result shows the degree of weathering influenced the physical and mechanical properties of mudrock. The sample with low porosity and high density possessed highest slake durability index of 91.43%. X-Ray diffraction revealed two of the sample tested were consists of goethite and quartz. The sample presence with goethite is higher in durability compare to sample consists of quartz only due to the cementation effect and denser minerals.

This paper studies the numerical failure mechanism of the solder joints in the ball grid array (BGA) package under thermal reliability process. The package consists of the silicon die, the Flame Retardant 4 (FR-4) substrate and the FR-4 printed circuit board (PCB). A total of 64 95.5Sn-4.0Ag-0.5Cu (SAC405) solder joints with a diameter of 0.46 mm are arranged together in area array fashion with a pitch distance of 0.8 mm. Only a quarter-model of the package is simulated since all the geometry, loading and boundary conditions (BC) is symmetry at the centre of the package. The package is exposed with thermal loading, initially at the liquidus temperature of 220°C to room temperature (25°C). Then, it follows with 3 additional thermal cycles between 125°C and -40°C with a ramp rate of 11°C/min and 15 minutes dwell time, respectively. Unified inelastic strain model (Anand model) was used to compute the inelastic behaviour of the solder joints. Results show that the stress level at the critical solder joints and the corresponding inelastic strain are 39.91 MPa of 0.2083%, respectively after the end of the solder reflow cooling process. As predicted, the inelastic strains accumulate continuously in the solder joint throughout the temperature cycles. Additionally, in the critical solder joint, both high stress and inelastic strain gradients are localized near to the solder-IMC interfaces. Prolong the thermal cycles can extensively accumulate the inelastic strains which lead to fatigue crack and subsequently crack propagation in the solder joints. After the end of the FE simulation, the highest stress and inelastic strain predicted are 57.96 MPa and 0.5781%, respectively.

Micro Aerial Vehicles, otherwise known as MAVs, is defined as an aerial vehicle that has a 15cm or less wingspan with a take off wight of less than 200g. Its miniature size and manoeuvrability allows it to fly in confined space at low Reynolds number flight conditions (100 – 100,000). In this study, an entothopter design inspired by dragonfly wings was investigated using a subsonic wind tunnel to see the effect of tandem wing configuration on the lift generation. The study was done at different flapping frequency (5-11Hz) and at different flight speed (5m/s, 7m/s, and 9m/s). It was observed that in phase flapping configuration produces better lift for all flapping frequency and all flight speed.

Biodiversity analysis was carried out on Garcinia mangostana pericarp (GMP) which underwent spontaneous fermentation. Population dynamic was carried out using the plating method while genotyping employed gene sequencing of 16S rDNA (bacteria) and 5.8S-Internally Transcribed Spacer (5.8S-ITS) rDNA (yeasts). Throughout 90-day fermentation in 5-L fermenter (laboratory scale) ecosystem, the prevalence of lactic acid bacteria (LAB) and yeast were indicated by their viable cell counts at 10³ to 10⁴ colony forming unit per ml (CFU/mL) on MRS medium and 10³ to 10⁷ CFU/mL on PDA medium respectively, while the prevalence of LAB and yeasts in 50-L fermenter (pilot scale) ecosystem were marked by 10³ to 10⁷ CFU/mL and 10² to 10⁵ CFU/mL on the respective medium. Complete inhibition of enterobacteriaceae population conferred a microbiological safety of the fermented GMP. Genotyping of isolates revealed Firmicutes and Proteobacteria in 5-L fermenter ecosystem, while Firmicutes and Proteobacteria were isolated from 50-L fermenter ecosystem. Lactobacillus plantarum and Enterococcus faecalis were amongst probiotic species isolated from 5-L and 50-L ecosystems respectively, whereas Saccharomycetaceae yeasts were ubiquitous in both ecosystems.

Self-compacting concrete (SCC) a latest innovation in concrete technology is being regarded as one of the most promising developments in the construction industry due to numerous advantages over conventional vibrated concrete. SCC is an innovative construction material that can be placed into forms without mechanical vibration which able to flow and consolidate under its own weight. The utilisation of quarry dust (QD) as waste and eco-friendly material in SCC was investigated in this study. Conventional vibrated concrete mix was designated as OPC while SCC mixes with different percentages of QD which are 0%, 10%, 20%, 30%, 40% and 50% that had been used to replace sand as partial fine aggregate. The high-range superplasticizer had been used as the chemical admixtures that can enhance the rheological properties of all SCC mixes. The performance of conventional vibrated concrete and QD in SCC in terms of its workability was investigated while the durability performance was investigated by conducting water absorption test and water permeability test for curing periods of 7, 28 and 60 days were considered in this study. 50% of QD is the optimum dosage that can be used in order to achieve the lowest water absorption meanwhile 40% of QD is the optimum dosage that can be used in order to achieve the lowest water permeability for QD in SCC mix. In conclusion, the innovation material by utilising QD in SCC improve the workability and durability performance of concrete.

An experimental study has been carried out to evaluate the emission characteristics and exhaust gas temperatures of algae oil additive in diesel blends. Diesel fuel (D100) and fuel blends of algae oil at 1% (A1), 2% (A2), 3% (A3) and 4% (A4) concentration were prepared and put to test on an unmodified single cylinder diesel engine. The test was conducted at a constant engine speed of 1500 rpm with varying engine load (0, 2, 4 and 6Nm). The engine performance of exhaust gas temperature and exhaust emissions of carbon monoxide (CO), carbon dioxide (CO₂), and oxide of nitrogen (NO_x) were measured and analyzed. The results showed that the properties of algae oil additive were comparable to diesel fuel and it was successfully used to run the diesel engine. In terms of exhaust emissions, A4 blends exhibited lowest CO and NO_x emission by about 90.9% and 21% lower compared to pure diesel D100 at engine load of 6Nm, respectively. However, A4 blends also exhibited the highest CO₂ percentage emission which is about 31% more than D100 and exhaust gas temperature of 1.22% higher compared to D100 at 4 Nm engine load.

The main purpose of the engine lubrication system is to supply lubricating oil to all moving parts in the engines to reduce friction rates. The failure of this can cause damage to the engine system. The aim for this project is to develop a user-friendly device to predict as accurately as possible the next oil change for an automobile. The device consisted of four main parts, the electronic part, the heating element, the main body and the cover. A 12V DC motor is used to measure the current as the shaft connected to the motor immersed in fluid which temperature is controlled at 40 Celsius. The experiment was conducted using waste oil lubricant (WLO) collected from an automobile servicing centre. The behaviour of a given fluid was analysed using data generated. A measure of viscosity was calculated. The upper limit of viscosity change is set to +15% change and -10% for lower limit. The result shows the deterioration of WLO in term of viscosity. From the sample tested with the device, all the WLO were overused as the oil was over the allowable limit of viscosity changes which could present a danger of possible damage to the engine. Therefore, this device can function as a preventive maintenance device of car as the user can predict when is the best time to change their automobile oil lubricant.

Maximum shear modulus (G_max) is a crucial parameter in the prediction of ground deformation and performance of seismic design. Practically, the G_max parameter could be obtained from specific laboratory test or seismic field test. Bender element (BE) test is nondestructive laboratory test, which is simple yet reliable method in determining G_max of soil. This study focuses on application; processes and analysis of G_max values obtained from BE laboratory test using continuous wavelet transform (CWT) method. The G_max values were validated with results from field seismic dilatometer test (sDMT) conducted at the same site of soil sampling for BE laboratory test. BE laboratory tests were conducted on undisturbed Auckland residual clay at various effective confining pressures (ECP) under fully saturated condition. The G_max values analysis between CWT and field sDMT data were based on the overburden pressures values that matches with ECP applied in the BE laboratory test. In summary, the comparison between CWT analysis of laboratory and field sDMT data indicated good consistency of G_max values. Thus, confirmed the reliability of CWT method in estimating G_max parameter from BE laboratory test.

Asphalt cracks are one of the major road damage problems in civil field as it may potentially threaten the road and highway safety. Crack detection and classification is a challenging task because complicated pavement conditions due to the presence of shadows, oil stains and water spot will result in poor visual and low contrast between cracks and the surrounding pavement. In this paper, the network proposed a fully automated crack detection and classification using deep convolution neural network (DCNN) architecture. First, the image of pavement cracks manually prepared in RGB format with dimension of 1024x768 pixels, captured using NIKON digital camera. Next, the image will segmented into patches (32x32 pixels) as a training dataset from the original pavement cracks and trained DCNN with two different filter sizes: 3x3 and 5x5. The proposed method has successfully detected the presence of crack in the images with 98%, 99% and 99% of recall, precision and accuracy respectively. The network was also able to automatically classify the pavement cracks into no cracks, transverse, longitudinal and alligator with acceptable classification accuracy for both filter sizes. There was no significant different in classification accuracy between the two different filters. However, smaller filter size need more processing training time compared to the larger filter size. Overall, the proposed method has successfully achieved accuracy of 94.5% in classifying different types of crack.

Green concrete was introduced in concrete production in order to reduce the usage of natural resources. In this research, fly ash and MWCNTs were used in the production of green concrete since industrial waste material such as fly ash becomes a major concern during waste disposal. MWCNTs was used in this experiment to strengthen this green concrete. In this paper, effect of heat during curing process was studied and it was found that the compressive strength was increase when introducing the heat during curing process of this green concrete. The 3 days of water curing at room temperature and 3 days of heat curing at 100°C produces compressive strength at 27.2 MPa which is higher than normal curing process at 28 days, which is 14.63 MPa. Therefore, this research shows that green concrete can be produced using fly ash and MWCNTs and produce high compressive strength when heat was presence during curing process.

Geopolymer based cementitious materials were produced to reduce or completely eliminate the use of cement in concrete in which could be incorporated with waste materials. In this study, rice husk ash (RHA) which is a waste having rich in silica content after burnt was intended to be used as based geopolymer. Besides, sewage sludge ash (SSA) was incorporated with RHA producing geopolymer mortar in which also having pozzolanic element of Si and Al. Geopolymerisation requires Si and Al elements to react with highly alkaline solution to produce geopolymeric material. Therefore, combination of RHA and SSA will be possible solution as base geopolymer mortar in order to provide Si and Al. The effect of SSA inclusion was investigated under different sodium hydroxide (NaOH) molarity and curing conditions to the strength development. NaOH and sodium silicate were used as activator with ratio of 1:1 and the solution to ashes ratio of 1:1 was used. Compressive strength was tested at 7, 14 and 28 days. The results showed that the geopolymer mortar made of SSA replacement exhibited higher compressive strength with reference to those made of RHA (control sample). In addition, the results showed that geopolymer mortar specimen containing 15% of SSA replacement activated with 8M NaOH solution gave the highest strength recorded 15.0MPa in oven curing condition (60°C for 24 hours). As conclusion, SSA up to 20% replacement has potential to be used in producing geopolymer as replacement alternative to RHA.

The demand uses of plastic are increasing day by day leading to the various outsized amount of plastic waste producees across the world. Therefore, a proper discarding of the plastic wastes without causing any environmental risk has become a real challenge. The reuse of plastic to a beneficial product is one of the sustainable options which can secure the environment and prevent the plastic discarded to the landfill or incinerated. In this study, laboratory test was conducted to analyse the potential of recycle plastic waste as liner material in engineering application. The plastic waste was fabricated as 2mm plastic sheet liner and the geotechnical behaviors namely shear strength was analysed and compared with the commercialized liner which known as the geomembrane. Results of shear analysis showed the cohesion between the fabricated plastic waste liner (FPWL) meet the reference value for cohesion ranging 10-24 kPa. However, for internal friction most of the FPWL samples did not meet the reference value for internal friction ranging between 25-35o. This shows that plastic waste has a good shear strength and meet with global factor which feasible as alternative liner material in engineering application.

The wing profile for Micro Air Vehicle (MAV) can be easily developed through the polynomial equation method which is proven in generating good aerodynamic performances. However, the study demands more studies in profile configurations to provide more evidence which interrelated with its aerodynamic performances. Thus, in this works, an aerodynamic study on different wing profiles configurations has been carried out. Profile 1, Profile 2 and Profile 3 were developed through the 3rd order polynomial equations have analyzed based on simulation works by using ANSYS-CFX. Based on the lift distribution analysis, it shows that Profile 3 has a huge advantage in generating better lift distribution (C_L) among the wing profiles. Profile 3 able to produce at least 20% to 22.9% better maximum lift coefficient (C_Lmax) and C_L magnitude compared to the other wing profiles. Despite its benevolent in C_L performances, Profile 3 has induced the highest drag (C_D) penalty among the wing profiles. Profile 3 has consistently produced at least 57.5% higher C_D magnitude compared to other wing profiles. However, in terms of moment coefficient (C_M) performances, Profile 3 has shown a promising ability in providing better wing stability compared to the other wing profile due to steeper C_M slope.

A total of 284 bulk unit weight data were obtained from soil samples collected from 29 failed slopes and 10 stable slopes in Penang Island and Baling, Kedah. Both study areas are located in the Northern Malaysia. Field bulk density tests were performed at all the locations where disturbed soil samples were also collected to determine the other basic important properties of the residual soils. The highly variable values of bulk unit weight are due to the high complexity and variable formation of the residual soils. The objective of this research is to determine the best-fit distribution of the highly variable values of bulk unit weight of the soil taken from the stable slopes and failed slope especially in Northern Malaysia. This research also aims to determine the mean value of bulk unit weight of residual soils. The bulk unit weight data was tested based on Kolmogorov-Smirnov method using SPSS software, to check the normality of the data distribution. The best-fit distribution for the variation of bulk unit weight of the residual soils taken in the Northern Malaysia was normal distribution. The mean value was found to be 17.30 kN/m³. The range of bulk unit weight found here is within the range that was found by the earlier researchers.

The infiltration of oxygen is unfavorable since it burned away the biomass. Other parameters were also contributed to the production of biochar. The experiments on mangrove wood were conducted using a fixed bed pyrolysis reactor with the temperature range of 300°C to 600°C, oxygen range from 0% to 10% and holding time from 2 hours to 4.4 hours. Response surface methodology (RSM) was implanted for process optimization. There were a significant effect of oxygen percentages and holding time on the production of biochar yield within the range of study. Results show that the optimum biochar yield of 15.2% when the pyrolysis temperature, oxygen percentage, and holding time were 402.5°C, 2.29% and 2 hours respectively. Confirmation experiment showed that 15.1% of biochar yield was obtained with the same pyrolysis parameters which validated the previous optimization.

Reinforced concrete structure is widely used in Malaysia as a common structural system of a building. As a common understanding, reinforced concrete is also known as a composite structure that combined two type of materials which is concrete and steel. Due to rapid development of residential houses, this situation was creating to higher energy consumption by producing high content embodied carbon emission Therefore, three main criteria should be considered in sustainable development that is economic, environment and social in order to produce better environment. This study was developed to produce eco-efficiency design of single story residential house for different optimization of concrete characteristic strength by using economical score and environmental score analysis method. Finding was recorded blast furnace slag reinforced concrete produce an eco-efficiency design than fly ash reinforced concrete due to positive impact to the economical and environmental criteria. Therefore, it can be concluding that waste materials need to be analyzed as an alternative material in concrete because it may produce high content of embodied carbon that give negative impact to the environment.

Lightweight mortar panel has been an alternative wall in the construction. However, the unsteady distributions of loads to the panel due to disorder alignment during construction affect the capability of the wall to reach the optimum load capacity. The inclusion of expanded polystyrene (EPs) that less in density and strength also was contributed the factor to achieve cohesiveness the properties of mortar panel. Therefore, this study aimed to determine the load capacity of the panel under axially eccentric loading that comply with the design of plain wall in BS8110-1. Due to this type of loading, the deformation was investigated through the load-strain, buckling profile and failure mode. This research involves laboratory experimental work for the different panel's height. Four variables of EPs proportion were designed in a dry-mix mortar and constructed into the panel. From the result, the panel failed in compression stress where the wall deflected in single and double curvature at the vertical position. The high slender panels were failure at the joint of panels with the maximum deflection of 3.96 mm. Meanwhile, the low slender panel tended to crack and bend at the top. The ultimate eccentric load obtained for the panel at 45% EPs replacement was 587.76 kN.

Concrete performance and workability can be improved by using an optimum amount of fly-ash. This leads to the purpose of analysing the percentage of fly-ash that can replace a certain amount of Portland cement in the concrete until it reaches the maximum strength. The experiment was conducted using G25 and G45 concrete supplied by a local ready-mix concrete plant in Kuching, Sarawak. The cement content of each concrete grade was replaced with various fly-ash percentages of 20, 30, 40, 50 and 60 collected from waste materials in Pending Sarawak. The specimens used in the studies were made of 150mm concrete cubes. Specimens were tested for compressive strength at the ages of 3, 7, 14, 28, 56 and 90 days. The curing age extended to 56^th and 90^th-day to participated slow pozzolonic reaction process contributed by fly-ash. Based on the test results for both concrete grades with enhancements, the compressive strength significantly increases from 7 days to 56 days, and then slightly increases on the 90^th-day. The G25 concrete has an optimum strength with a fly-ash replacement of 30% cement content, followed by 40%, 20% and 50%. Similarly, the G45 concrete achieved an optimum strength with a fly-ash replacement about 30% cement content, followed by 20%, 40% and 50%. In addition, both grades of concrete tested have a cut-off cement replacement level of 60%, beyond which the compressive strength falls below that of the control mixtures.

Composite materials have been widely used in many applications but understanding their failure behavior is always challenging. For years, numerical investigation has been the effective alternative, even though the underlying theories related to composite materials are complicated. This study aims to investigate the improved strength of hybridization by comparing the failure behavior of glass-epoxy composite laminate and hybrid glass-graphite-epoxy laminate under transverse sinusoidal load. The composite and hybrid composite laminates with various aspect ratios were modelled using ANSYS. The plates were simply supported and transverse sinusoidal load were applied until failure occurs. Initially, numerical validation was performed and the simulated results are found to be close to the 3D elasticity analytical results. In general, most simulated parameters produced error less than 2% and thus proving the reliability of the finite element models and implementation. The first ply failure (FPF) and last ply failure (LPF) curves were plotted to compare the failure trend of glass-epoxy composite laminate and its hybrid laminate. The results showed no significant difference in the FPF trend but hybridization could withstand up to 80% more normalized load in terms of the LPF. In conclusion, the present study has shed new knowledge about the failure behavior of hybrid laminate and thus, this knowledge could be applied in designing hybrid composite laminates.

In Malaysia perspective, the application of nanotechnology is crucial towards achieving the country's objective as a developed nation by 2020. This paper aims to examine the current Malaysia laws and statutory regulations of nanotechnology applications, to investigate the occupational diseases and work-related accidents associate to nanotechnology and to examine the risk assessment and management practices executed by the nanotechnology-based manufacturers to facilitate the potential effects of nanomaterials. Nanotechnology is a technology that incorporates nanomaterials, which is extremely small materials in size, equivalent to 1/80,000^th of the width of a human hair. Due to their distinctive size, these nanomaterials may contribute to the significant health risks and hazards. The findings conclude that there is no specific law and statutory regulation on nanotechnology application exists in Malaysia. Thus, the none existence of nanotechnology laws means there is no protection of persons at work. Malaysia is currently formulating safety standards relevant to nanotechnology. Recently, the Department of Occupational Safety and Health (DOSH) has published the Guideline on Control and Safe Handling Nano Materials by the end of 2018. It provides information and recommendations on handling nanomaterials in the workplace. According to the DOSH personnel that there is no record of occupational disease and work-related accidents related to nanotechnology per se. In relation to the risk assessment and management activities, most of the respondents from the nanotechnology-based manufacturer indicated that there is no nanotechnology risk assessment and management practices being executed in their workplace. Most of them also concluded that they have no knowledge about the latest guideline published by the DOSH on control and safe handling of nanomaterials in the workplace.

In the current construction industry, the selection of structural design was important in order to ensure the design were satisfied in term of economic, environment and social as for the purpose to fulfill need of sustainable development. Eco-efficiency has been introduced to be used for the decision-making method in selection of the best design that fulfill requirement of sustainability. This study was develop to integrate analysis of eco-efficiency index for reinforced concrete structural elements by considering economical score and environmental score as a main approach. The classification of the design case for single story and double story house took place from low level to high level of eco-efficiency based on its eco-efficiency index. Result shows single story house was classified from medium low to medium high eco-efficiency design level for all 10 cases while for double story house was classified from low to high eco-efficiency design level.

Railways in Malaysia are undoubtedly a various incorporated element that can possibly assume as an imperative part in the advancement of a manageable transportation framework in the nation. Therefore, failure of prestressed concrete sleepers under the negative static loading need to be investigate due to its role as one of the important part in railway. In this study, negative moment test was established to investigate the design load of the prestressed concrete sleeper (PCS) under negative static loading. Three (3) samples of PCS were used and one (1) PCS contains two rail seat, called KTMB and EPMI sides. It is found that new crack appeared on EPMI sides with the length of 100 millimeters. Meanwhile, the highest displacement for EPMI and KTMB sides were found to be 7.332 and 6.606 millimeters. From three (3) samples tested, only one PCS shows the failure to cater the design load of 176.94 kN subjected to rail seat.

The tubercle effect is a recently discovered phenomenon where the sinusoidal pattem 'bumps' on the leading edge of an airfoil can improve the aerodynamic performance. This effect was inspired by looking at the humpback whale pectoral flippers that give an exceptional acrobatic manoeuvrability in the water such as somersaults, also allowing for easier capture of prey. The objective of this research is to study the effect of implementing the tubercles concept on the car spoiler in order to see whether it bring advantage or disadvantage in the aerodynamic performance of a car. The design and simulation process are done by using Solidworks. The design of airfoil spoiler based on Selig S2091 (low Reynolds number airfoil) with sinusoidal pattern leading edge were computationally used. The Airfoil spoiler with 270 mm of the chord length (C), 1200 mm wingspan (L) and angles of attack of -5°, 0°, 5°, 10°, 15°, 20°, 25°, 30° were improvised with tubercles at 40 mm amplitude of bumps (h) and the distance of the wavelength between peaks (λ) of 1200 mm, 240 mm and 133.33 mm. The simulation was tested at 40 m/s. The investigation shown that the tubercles can improve the aerodynamic performance of car rear spoiler where the tubercles are able to increase the lift coefficient but has a significant decrease in drag only at 20° and above angle of attack.

The Er³⁺-activate dielectric thin film can be applied to produce planar waveguide amplifiers that can be integrated with other active or passive devices on the same chip. However, Er³⁺ tend to cluster in host material especially in silica when doped at high concentration. This issue can be overcome by introducing Z1O2 as a co-host material in a silica glass matrix by helping to disperse Er³⁺ homogeneously and consequently enhance the output intensity. In this work, we present a study on 70SiO₂-30ZrO₂ glass ceramic doped with a various concentration of Er³⁺ prepared by the sol-gel dip coating technique and each film obtained were annealed at 900°C. Full film densification was achieved for the deposited film, which indicates the hydroxyl group was successfully removed as shown in Raman spectra. Refractive index of the film increase with the increment of rare earth ion and this permit the guiding of light in the film. Red and green emissions of Er³⁺ were detected upon 514.5 nm excitation. Nevertheless, the presence of higher Er³⁺ (0.58 mol%) induces concentration quenching phenomena as shown in the PL spectra where there is a decline in green emission peak.

Subgrade soil is important for design purpose of both flexible and rigid pavement structures; flexible and rigid. The quality of flexible and rigid pavement structures is correlated on the strength and stabilization of subgrade layers. The main function of subgrade is to act as a foundation for pavement layers and supporting the load which is transmitted from the overlying layers. The marine soil is a problematic soil which low in strength and do not suitable for road embankment for highway construction. Therefore, the soil strength can be improved by adding stabilizer or admixture to increase its strength. Soil stabilization change its physical and mechanical properties from its original soil. Thus, the physical properties of marine stabilized with cockle shell powder were determined and the potential of Cockle Shell Powder (CSP) as soil stabilizer based on percentage added in CBR test was investigated. Based on previous research, the performance of soil mixed with CSP in the proportion of constant 2.5%, 5%, 7.5% and 10% was examined with CSP properties and California Bearing Ratio (CBR) tests. The results obtained indicates an increment in specific gravity and decreasing in the plastic index (PI) with the addition of 2.5% of CSP. The CBR and PI show a good correlation and thus inclusion of CSP in marine soil could be used as alternative material for subgrade layer in increasing soil strength.

The internal combustion process to move the vehicles had indirectly releasing waste heat into the environment which contributed to global warming. Thermal-electric Cell (TEC) is a device that able to convert thermal energy to electrical energy cleanly. The TECs system work when it is sandwiched between the hot and cold side. The objective of this study is to investigate the possibility of tapping a waste heat using thermoelectric cell (TEC) from car exhaust. The experiment had been carried out in stagnation condition in the laboratory using 1500 cc petrol engine DOHC (4G91). Four TECs (SP1848-27145) were connected in series on the top of exhaust muffler. The experiments were run in two type of cooling methods using air flow from standing fan and the flowing cold water. The maximum voltage of 2.42V was produced when temperature difference, DT reached 83°C. The LED bulbs were connected to TEC and light up when the voltage of 1.60V is obtained. The results have proved that the temperature difference between two sides is the dominant effect to determine the TEC performance. The generated power could be utilized to power an auxiliary application in the vehicle itself.

In this study, the aerodynamic performance of a car spoiler with tubercles configurations that was inspired by Humpback whale flipper morphology was investigated. This was done by producing three (T0, T3, and T9) spoiler designs where, tubercles sinusoidal protrusions pattern was applied at the leading edge of the spoiler. T0, is a base line spoiler that has no tubercles, T3, that contains three tubercles protrusions, and T9, contains nine tubercle protrusions. The baseline spoiler design was based on the Selig s2091 spoiler and the spoiler has a chord length (C) 100mm and 290mm wingspan. The spoiler was tested angle of attack from - 20 to 30° and at Reynolds number 60000 in an open circuit subsonic wind tunnel. The aerodynamic performance of the spoiler was measured by the recorded time averaged lift and drag. From the recorded it was observed that at certain angles of attack, the presence of a tubercle pattern can bring a significant aerodynamic improvement.

Recent previous studies have shown that there is a correlation between heat conductivity and surface materials. In this project, the heat conductivity 3 different samples of T2 copper with different surface roughness was studied. This was done by measuring the temperature of the samples at 9 different point using SOLTEQ Heat Conduction Study Bench (Model HE106). The surface roughness of the different samples was achieved using sandpaper and measured using the (SURFTEST SJ-410) where the different surface roughness was A: Ra=0.379μm, B: Ra=0.71μm, C: Ra=0.053μm. The sample was heated using a heater with 10W of power. From the collected data, it was observed that the specimen with the smoothest surface roughness has the best performing heat transfer with the specimen C that have the highest decreasing percentage temperature followed by specimen B and specimen A.

Electrochromism is the phenomena of reversible colour change in electrochromic (EC) materials due to a small applied voltage. Tungsten oxide (WO₃) is one of the most studied cathodic electrochromic materials for its applications in smart windows, displays and rear-view ymirrors. In this work, WO₃ films were fabricated on indium tin oxide (ITO) coated glass via the sol-gel spin-coating method. The influence of bias voltage on the EC properties of the fabricated WO₃ films was studied. The optical properties were characterised by using ultraviolet-visible (UV-Vis) spectrophotometer and the EC properties were characterised by the chronoamperometry (CA) method. The fabricated WO₃ films exhibited an optical transmittance of 80 % in the visible range. CA measurements revealed an increase in colouring and bleaching time and intercalated charge density as bias voltage was increased. Moreover, the colouring and bleaching transmittance of the WO₃ films were found to decrease as bias voltage was increased. Within our measurement range, bias voltage of 1.0 V was found to be the optimum bias voltage where it corresponds to 34 % optical modulation and higher colouration efficiency of 22.6 cm²/C.

The increasing number of Alum Sludge (AS) in water treatment plant (WTP) from water treatment process has been directed to the reduction of storage capacity for keeping of AS waste itself in the landfill. Other than disposed in the landfill site, this accumulated AS can be commercialized into a useful product such as landfill barrier. Conventionally, clay is used as the protection layer in the engineered sanitary landfill to reduce the leachate intrusion into groundwater. However, due to higher usage and demand on the clay (C) material caused its depletion and higher in cost. Therefore, accumulated AS can be recycled and reused to reduce the disposal problem in landfill and financial burden facing by the landfill operator. In this study, AS was investigated and compared with the kaolin clay (KC) in terms of XRD and SEM characteristics. The index properties and hydraulic conductivity, k test were also conducted to classify the AS and KC composition. Based on the testing, AS can be classified as High Plasticity Clay and the value of k for AS is higher than KC. Based on the results from XRD, both of KC and AS samples was having a similar crystalline phase which is Quartz. Based on the summary of compounds elements, the chemical elements of Oxygen, Aluminium, Silicon and Iron presence in AS have a quite similar percentage of weight (%) with KC. From all of these results, it can be concluded that the AS is mostly having similar materials to KC and amorphous in nature.

Dye-sensitized solar cells (DSSCs) are one of the most promising third generation solar cells and have been regarded as a competitive alternative to the conventional silicon-based photovoltaic devices due to their relatively low production cost. Light soaking effect is an intriguing phenomenon that exists in DSSCs, which refers to the enhancement of the electrical parameters in the cells after being exposed to light soaking. In this paper, we report on the variation in the electrical parameters of DSSCs under continuous exposure to a simulated solar irradiation for a period up to 6h. Increments of Jsc and Voc in DSSC were observed after 6h of light soaking, which led to improved efficiency from 3.87% to 4.50%. The improvements may be ascribed to the formation of electron trapping states below the TiO₂ conduction band edge, which facilitated the charge carrier transport.

In this paper, we report the realization of ultraviolet (UV) photodetector based on doped ZnO films. The ZnO p-n junction was fabricated on indium tin oxide (ITO) coated glass, which consists of n-type and p-type layers based on Ga-doped (2 at.%) and N-doped (20 at.%) ZnO films, respectively. The current-voltage (IV) characteristics, photosensitivity, photoresponsitivity, and photocurrent gain were derived to determine the performance of the device. At 5 V reverse bias, the ZnO-based UV photodetector exhibits photosensitivity of 10.9, photoresponsivity of 2.1 × 10⁻² AW⁻¹, and photoconductive gain of 7.2 × 10⁻².

Corrosion of rebars in reinforced concrete structure is a big universal problem created by saline water ingress causing rebar and other metal structural member to corrode. The deterioration of concrete structures due to the harsh environment conditions leads to the deterioration of the reinforced concrete performance structure, and the premature deterioration of the structure before completing due to carbonation or the chloride content of the future services is expected to be the primary concern for engineers and researchers. Progress of corrosion location cannot be visually evaluated until the point when crack or a delamination is appearing. Therefore, in the study, the Ground Penetrating Radar (GPR) is used to investigate the artificial rebar corrosion damage on steel rebars. The methods showed the artificial rebar corrosion damage can be detected and quantified without damaging the surrounding concrete material. GPR showed the potential on detecting rebar corrosion damage on large areas and in a rapid manner.

Rheology of film solution is important to determine the final characteristics of biopolymer film as packaging material. In this study, the dynamic rheological properties of cassava starch-kaffir lime oil film solution were determined. The rheology measurement was made at frequency of 0.1 to 10 Hz and 1 % strain at 25 °C. The storage modulus (G'), loss modulus (G") and complex viscosity (η*) were determined to know the viscoelastic behavior of the film solution. The magnitude of G' was greater than G" for all samples which indicated that the film solution was a gel-like; that is, the film solution behaves more like a solid where the deformations were elastic and recoverable. All samples show increasing trend of G' and G" as the frequency increased. The complex viscosity decreased with increasing frequency which presented a shear thinning behavior of the film solution. The dynamic rheological properties of cassava starch-kaffir lime oil film solution was determined appropriately, thus the characterization of produced biopolymer film by casting can be correlated.

Illumination level is an important thing in our daily life. Therefore, it is necessary for the building or any infrastructure to achieve the minimum recommendations of illumination. This case study was focus on the evaluation of illumination level at public transit infrastructure which is Pengkalan Sultan Abdul Halim Ferry Terminal. The aim of this study is to evaluate either the illumination level in selected area is comply to the standard of Panduan Teknik JKR or not. Field measurement was conducted, and the reading of lux meter were recorded. The illumination level of the selected location is in good condition during the day. The walkways area achieved 100% of recommendation standard followed by waiting area is about 85%. Only ticket counter in satisfactory level with 86.20% and only 13.80% achieved the minimum requirement. Only walkways achieved 65.4% of satisfactorily standard and 34.6% in bad condition for the night situations. The bad condition of illumination at ticket counter and waiting area during the night. The 100% of the area are in bad condition which is dangerous to the users. From the results, it is suggested to do routine maintenance to improve the illumination level and achieve the minimum requirement of standard.

The natural fiber composites product becomes popular among the world to promote sustainable development. Unlike the synthetic fibers, natural fibers can absorb as much as the carbon dioxide to prevent the global warming happened. Natural fiber composites such as kenaf mixed with polypropylene, have been commercialized in automotive parts due to its lightweight ability which can improve the fuel efficiency. The main objective of this study is to investigate the effect of injection moulding temperature to the shrinkage and tensile properties of kenaf/polypropylene key chain product. The optimum weight fraction of 30 wt% kenaf and 70 wt% polypropylene was fabricated using different temperatures of the injection moulding process. The best physical appearance of the key chain was prepared at 180°C. The sample that was fabricated at 210°C has higher tensile stress and tensile modulus which are 12.48 MPa and 1.03 GPa, respectively. As a conclusion, the kenaf/polypropylene specimen prepared at 210 °C has better tensile strength and less shrinkage if compared to others. Brittleness due to voids formation was evident in the SEM image of the kenaf/polypropylene. By using the injection moulding process, a high volume of products could be produced in a very short time.

In this study, polylactide (PLA)/montmorillonite (MMT) composites were prepared by melt intercalation technique. Three types of MMT, Cloisite® 30B, Cloisite® Na⁺ and Cloisite® Ca⁺⁺DEV were used as fillers. The morphology and mechanical properties of the composite materials were investigated and compared with unfilled PLA, keeping the same thermomechanical history. The morphology of the composite materials was evaluated by small-angle x-ray scattering (SAXS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the tensile properties of these composites were measured by an Instron universal testing machine. The morphology observations showed that the good affinity between the organo-modified clay (Cloisite® 30B) and the PLA was sufficient to form intercalated structure in the nanocomposite. Cloisite® Na⁺ and Cloisite® Ca⁺⁺ DEV clays exhibited a modest improvement of the young's modulus of about 18 % and 17 % respectively, due to poor dispersion in the PLA matrix as well as poor polymer-filler interactions compared to Cloisite® 30B. Compared to those of pure PLA, the PLA/Cloisite® 30B composites showed notable improvement of the Young's modulus of about 54 %.

Public transportation (PT) contributes to both the economical and physical health of individuals, it brings financial benefits to communities, and a key component of a healthy business ecosystem by increasing mobility options. The objective of this research is to develop a bus performance index of the existing PT system. This research utilised the multi-method approaches in Penang based on the perceptions and expectations of the bus users. A developed TRANSQUAL model is based on the existing SERVQUAL model, producing a set of 34 benchmark items and 7 dimensions that consist of reliability, safety, environment, responsiveness, accessibility, infrastructure and image as discussed in previous articles. Further study enhanced through the TRANSQUAL application, deficiencies of bus system performance in certain route is identified and might be improved. Subsequently, the bus performance index for each route was determined through the application of the mathematical composite index. Meanwhile, it can act as a monitoring aid to the service provider. At that point, service quality can be enhanced and the public will be attracted to use the buses as the main means of transportation.

Studies have shown that the angle of fiber orientation significantly affects the mechanical properties of a composite laminate. Although investigations on the properties of the composite material have been conducted, there is still a lack of studies related to Kevlar/Epoxy laminate. Therefore, this study aims to investigate the effects of the angle of fiber orientation to woven Kevlar/Epoxy laminates under a compression state. The study was conducted in two stages comprising of numerical validation and failure analysis. Maximum Stress Theory and Tsai-Wu Failure criteria were selected for the failure prediction. The laminates were made of 24 layers woven Kevlar/epoxy and the stacking sequence was (θ₄/0<₄-θ₄)s. The angle of fiber orientation, θ, was varied from 0° to 90° and failure loads for both flat plate and flat plate with circular hole were determined. The trend of displacement and failure behaviour for both type of plates were compared. From the results, it is found that the effects of the fiber angle on the plate with circular hole are more significant than the flat. Therefore, it can be reasoned that the current study is useful in contributing significant knowledge to better understand the failure behaviour of composite plate.

The utilization of conventional catalyst such as sodium hydroxide in biodiesel production possesses several disadvantages as they are difficult to separate from biodiesel products, particularly prone to soap formation and require a multiple neutralization step. For this reason, CaO derived from waste chicken eggshell was explored as an alternative catalyst. Normally, CaO from natural source was synthesized through the calcination process. Thus, this paper aims to identify the optimum condition of calcination process for high biodiesel yield. On the basis of statistical analysis, a central composite design (CCD) was used to optimize the calcination conditions which are calcination temperature and time to achieve high yield of biodiesel. The calcination temperature and time were varied in the range of 600 to 1000 °C and 60 to 300 minutes, respectively. The optimum calcination conditions are 900 °C and 3.5 hours, whereby the most significant factor affecting biodiesel yield was identified as calcination temperature. The result also indicated that the second order model was adequate for both independent variables on the response with R² of 0.9383. The maximum biodiesel yield of 92.81 and 94.72% were obtained by experimental and predicted values, respectively.

Pineapple is the third most consumed fruit in the world with an annual production of about 25 million tons. Usually, pineapple leaf (PL) becomes the waste after harvesting and most of the PL was burned to eliminate fungi, composted or just piled to rot. The aim of this study is to synthesize PL modified with diethylenetriamine (DETA) that contain amino groups (NH2) which enhance the adsorption capacity via the impregnated method. In order to prove the presence of NH2 groups on the surface of adsorbent after modification, the characterization analysis has been done. After the modification of PL with DETA (DETA-PL), the FTIR analysis shows the 2 peaks that attributed to the amino group. There also increased surface area, pore volume, pore size and the amount of N of DETA-PL as evidence of BET analysis and elemental analysis. The amount of N also increased after modification. The morphology of DETA-PL was smooth and crinkle after modification with DETA. The point of zero charges of DETA-PL was increased after the modification of PL. The finding obtained from all of the characterization analyses showed that there are presences of the amino group on the surface of DETA-PL adsorbent after modification. This suggested that DETA-PL is a promising adsorbent for an adsorption method of wastewater treatment.

Carbon dioxide (CO₂) is a greenhouse gas that produces from the combustion of fossil fuel. The consumption of fossil fuel in industrial activity has increased the concentration of CO₂ emitted in the atmosphere. When the concentration of CO₂ increases, the more heat are released. Thus, creating the global warming issue and climate change to the world. This climate change and global warming issue have attract the attention of worldwide. There are lot of carbon capture techniques proposed to overcome these problems. However, most of it are costly, and need a long dissociation and CO₂ separation process. Therefore, innovative technique and process optimization are needed in order to improve the process efficiency of this technology. The most common techniques used in this technology are cryogenic, biological technique, and membrane technique. Membrane technique with a biological approach has promising high CO₂ separation performance. This mimic enzyme based membrane has several advantages such as low cost, simple production procedure and high CO₂ separation performance. From the review, the use of PVA membrane integrated with mimic enzyme could be work together towards the improvement of carbon capture technology. This review provides the information and potential of an alternative approach of carbon capture technology to reduce the amount of CO₂ emitted from the fossil fuel industry.

Mariposa Christia Vespertilionis (MCV) or also known as butterfly wing leaves, is popular in the traditional medicine practice. The objective of this study is to optimize the antioxidant components (based on antioxidant activity analysis) from the MCV leaves extract using Supercritical Fluid Extraction (SFE) based on different temperature, pressure, and particle size via Response Surface Methodology (RSM). Besides that, it is also to evaluate the optimal condition of different extracting antioxidant activity from MCV leaves using Design Expert 10 software. The condition range for both pressure and temperature were between 150-350 bar and 30-70 °C with constant extraction time. The size of particle samples were between 63 μm-1000 μm. The antioxidant was analyzed using UV–vis Spectrophotometer (UV-vis). The lowest antioxidant activity was 8.20 % and higher antioxidant activity was obtained at 49.76 %. Lower absorbance indicated highest free radical scavenging activities. Maximum percentage (%) indicated high scavenging activities, thus higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) is a good indication for antioxidant. The predicted RSM optimal condition of antioxidant activity was at temperature 50 °C, pressure 282 bar, and particle size 500 μm, which the predicted antioxidant was 50.62 %. Upon verification through experiment, it was found out that the antioxidant activity value was close to the predicted value with an average error of less than 1%.

Palm oil fuel ash (POFA) is a waste material and generally disposed to open fields causing environmental pollution problems to the land and the air. Due to its abundance and high pozzolanic characteristics, it is highly potential to be used as civil engineering construction materials such as partial sand replacement in concrete. This paper presents the investigation of POFA as partial sand replacement in concrete. In doing so, two method of mixing processes were used namely powder and liquidation methods. The POFA was added in the concrete mix at various dosage levels of 0 %, 5 % and 10 % by weight of sand. Two types of testing were carried out; slump test for workability of fresh concrete identification and compressive strength test for strength identification of the hardened concrete cubes. The compressive strength test was carried out at 3, 7 and 28 days. The results from two different methods of mixing process were analysed, compared and discussed. From the results show that additional of 10 % of POFA by weight of sand is able to increase the strength of concrete at 28 days compared to other dosage levels. Hence, the POFA is given positive impact to be used as sustainable material in construction industry.

Semiconductor processing facilities regularly emit wastewater with fluoride concentrations exceeding 100 mg/L which can cause major health issues in the local population. This research aims to address this issue by optimising an electrocoagulation-adsorption (EC-AD) process using two aluminium electrodes and activated carbon. The applied voltage (5, 15, and 20V) and adsorbent dosage (0.20, 0.50, and 1.00g) parameters were varied to treat a synthetic wastewater solution containing 100 mg/L of fluorine. It was found that fluoride removal efficiencies are significantly affected by the adsorbent dosages and applied voltages used. Increasing the applied voltage from 5V to 20V increased the removal efficiency from 37.55% to 64.25% for 0.2g adsorbent dosage and from 33.85% to 67.25% for 0.5g dosage. After all the parameter combinations were tested, an applied voltage of 20V and an adsorbent dosage of 0.50g produced the maximum fluoride removal efficiency. These parameter values thus define the optimal conditions for the EC-AD process to reduce fluoride from highly concentrated wastewater. The AD, EC, and hybrid EC-AD process achieved fluoride removal efficiencies of 2.86%, 41.13%, and 67.25% respectively from synthetic wastewater. Therefore, it was showed that the combination EC-AD process performs better than adsorption (AD) or electrocoagulation (EC) processes used in isolation.

The performance of vegetable oil hydrotreating to produce green diesel in a slurry bubble column reactor was predicted in this study using a phenomenological model. A two-dimensional axisymmetric model of the reactor of 2.68 m in diameter and 7.14 m in height was used. The model consists of species mass transfer equations, an energy transfer equation and a pressure drop equation. Fluid mixing in the reactor was explained by dispersion coefficients. Catalyst distribution along the reactor was also considered. The chemical kinetics developed by Attanatho was used in the model. The effects of the gas and liquid superficial velocities on the triglyceride conversion as well as the green diesel yield and purity were predicted and evaluated. The effect of the superficial gas velocity on the reactor performance is insignificant since the range of superficial velocities in this simulation is in homogeneous flow area. The effect of the liquid superficial velocity is quite significant.

Composite edible coatings were made up from two types of polysaccharide which are cassava starch and carboxymethyl cellulose (CMC) incorporated with turmeric oil (TO) as an antioxidation agent. Weight loss, firmness loss and moisture content were studied to determine the effect of composite edible coating incorporated with different TO concentration and dipping times towards the quality of fresh-cut Fuji apples. Findings showed that the coating with 17.5 μL/mL concentration of TO and 180 s dipping time had the lowest weight loss and percentage of firmness loss. While for percentage of moisture content, 17.5 μL/mL concentration of TO with 60 s dipping time had the lowest moisture content loss. Surface morphology was analysed to observe the uniformity of coating on fresh-cut Fuji apples surface. The oxidase enzyme activities of fresh-cut Fuji apples reduce when there is TO present in edible coating. It showed that the coating with 180 s dipping time had the best surface coating compared to 60 s and 300 s dipping time. The composite edible coating emulsion can be huge potential as fresh-cut fruits coating to preserve the quality of the fruits.

Due to its extraordinary physical, mechanical and electrical properties, carbon nanotubes (CNT) have continued to develop since it was discovered in 1998. Domestic demand itself has not been fulfilled because the production costs are fairly expensive. Conventional CNT exhibits many toxic effects on invertebrates and also cause genotoxicity in rats and in humans. Camphor-based CNT production is cheap and easy to use for chemical vapor deposition (CVD) because of its volatile and non-toxic properties. This research was conducted with the floating catalyst method using ferrocene (Fe) as a catalyst precursor and camphor as a carbon precursor by varying the number of camphor mass by 1, 3 and 5 grams. The CNT Synthesis was performed silica balls and quartz shatter as the substrates, argon as carrier gas with flow rate 100 mL/min, and hydrogen as co-reactant with flow rate 70 mL/min. The operating temperature of the synthesis used was 800°C with a reaction time of 60 minutes. The results showed that camphor decomposed into three compounds which are 40% benzene, 8% toluene, and 52% xylene. The synthesis process with quartz as the substrate produces more carbon deposits than silica balls due to its better heat transfer and the purer silicon dioxide (SiO2) contained in the quartz. CNT has grown to follow a tip growth model with deformations such as the buckling growth model and a continuous growth model was also found. The biggest yield (25 mg/cm²) is obtained at camphor mass of 5 gram with a carbon percentage of 87.1% and average diameter 33 - 44 nm.

This research proposes a novel landing gear system using a four-bar linkage mechanism. The mathematical model of the landing gear system is calculated analytically. A simulation study is performed to investigate the landing gear performance in reducing the impact vibration response of the main system. It is found from the simulation study that nonlinear characteristic of the landing gear stiffness improves its impact vibration response. The simulation results show that rebound displacement and acceleration response of the main system using the proposed technique is smaller than that of using a conventional landing gear system.

In this study, tea waste (TW) is investigated as a low cost adsorbent for the treatment of Mn(II) and Zn(II) in synthetic wastewater. Experimental design, the variables are the adsorbent dosage (0.5g, 1.0g, 1.5g, 2.0g, 2.5g and 3.0g) and contact time (20, 40, 60, 80, 100 and 120 minutes). The percentage of heavy metal ions removal in the solution are measured using DR2800 Spectrophotometer. Adsorption Isotherm and Adsorption Kinetic modelling are applied to further prove the correlation of the experimental data obtained for the removal of Mn(II) and Zn(II). The equilibrium data satisfactorily fitted into Langmuir Isotherm model for both Mn(II) and Zn(II) with R² value of 0.9906 and 0.9854, respectively. Based on the result, TW is capable to adsorb more than 90% of both Mn(II) and Zn(II) at optimum dosage of 2g/100ml. The kinetic studies show that the absorption mechanisms satisfied the Pseudo-Second-Order model and have the best equilibrium data with R² value of 0.9998 and 1.0000 for Mn(II) and Zn(II), respectively. The maximum adsorption achieved at 60 minutes for Mn(II) and 80 minutes for Zn(II). Thus, the Langmuir Isotherm and Pseudo-Second-Order Kinetic models proved that TW is capable of being an efficient and effective adsorbent for Mn(II) and Zn(II) removal in synthetic wastewater.

Purification of NRL protein was accompanied by extraction of waste proteins using salting out and multiple centrifugation methods. Both methods contributes to varying degree of yield and purified protein characteristics. However both methods produces protein that can bind metal efficiently. Conventionally, salting out method was used and it is uncommon to use multiple centrifuge to extract protein. The key aspects discussed here, were on how the pH condition exposed to the NRL waste leads to variation in hevea protein extracted amount and how metal binding featured in FTIR spectroscopy. The purified protein were reacted with metal solution of different strength to study the binding characteristics. Molecular weight cut-off (MWCO) size of dialyzing tube shows greater effect on the final protein extracted amount by about 50% when smaller size were used. Acidic condition favors part of proteins from waste in purification while some favors basic condition. Standard salting out method shows consistent profile in extracting metal compared to multiple centrifugation method from 30 to 80%.

This paper presents the characterization of solar radio burst type III and IV obtained from e-CALLISTO website. Solar radio burst (SRB) is one of the tools in space weather studies as each type of SRB indicates the production of solar activity at that moment which can also bring it towards the prediction of solar events. Generally, SRB has five different type of emissions which are named as type I, II, III, IV and V, this paper will only focus on type III and IV. Data of type III and IV bursts were selected on 15^th Sept. 2015 and 27^th Feb. 2018 respectively and discussions on each type of bursts include two stations to make a comparison. At the end of this work, type III bursts show a rapidly drift structure from high to low frequency, strongly associated to solar flares and the burst is due to Langmuir waves. Meanwhile, type IV bursts are recognized by its broadband continuum with rapidly fine structure and they act as a hint of geomagnetic storm commencement. More details on the formation of these burst are discussed.

The magnetic field of the Sun plays the main role in the production of the solar flares until the enormous coronal mass ejections. The magnetic field can be observed from the sunspot on the Sun's surface. This paper is focusing on the production of the coronal mass ejection and solar flare based on the solar radio burst type II and III that occurred on 2nd April 2017 which were recorded by BLENSW site in Switzerland. The active region (AR) 2644 on the sun's surface that day had produced the M-class flare with the value of M5.3 which peaked at 0802 UTC. The region of 2644 had a magnetic classification of the beta-gamma spot where it contributes to the energy of the M class flare. The velocity of the flare moving through the interplanetary space was 588 km/sec. During that day, three significant shortwave radio blackouts affected the Indian and Pacific regions oceans. The coronal mass ejection produced was not facing the Earth and Kp index of 3 and the total interplanetary magnetic field with 5 nT were recorded. All data were collected from e-CALLISTO, CACTUS, Space Weather Live and Space Weather website.

The activities of metal oxide on zeolite as catalysts for production of fatty acid methyl ester from microalgae lipid oil were investigated by impregnation of MgO, CuO and NiO on zeolite 4A. The physical properties of the catalysts were characterized using TGA, XRD, Fe-SEM and Nitrogen Physisorption analysis. Evaluation on activity for biodiesel production from Chlorella vulgaris microalgae shows the trend of catalysts performance as CuO/Zeo>NiO/ZeO>MgO/Zeo. The amount of catalysts, the methanol to oil ratios and the length of reaction times affects the production of biodiesel with 69% of biodiesel produced using CuO/Zeolite catalysts at optimized conditions.

The conventional method of biodiesel synthesis is known to have a few drawbacks. With the intent of reversing the drawbacks, a research on biodiesel synthesis from triglycerides and methanol using cold plasma Dielectric Barrier Discharge (DBD) reactors was conducted by using two types of plasma carrier gas, namely argon (Ar) and a mixture of Ar + CO₂ + H₂O (vapor) by varying the temperature and reaction time systematically. The major products obtained from the cold plasma dielectric barrier discharge (DBD) reactor consists of four primary components: FAME (fatty acid methyl ester) or biodiesel, alkane (paraffin) and fatty alcohol and/or other side products which were analysed using GC-MS and FT-IR. The analysis was carried out mainly to determine the chemical conversion associated with reactant or biodiesel products. The types of triglycerides used in this research are (a). used cooking oil, (b). used mixtures of used palm oil and fresh palm oil, and (c). used mixtures of used palm oil and fresh castor oil. With the synthesis time for 2 hours, it was found that the cold plasma DBD reactor was able to change about 47- 89 % mixture of triglycerides (without catalyst and excess methanol) to various product such as FAME, greendiesel paraffin and fatty alcohols. It seems the uses of Argon Gas produce a 23.7% higher yield of FAME and paraffin than the mixture of argon and CO₂.

This paper presents the experimental investigation conducted on Grade 30 concrete incorporating agro-industrial waste, Palm Oil Fuel Ash (POFA). The emergence of palm oil industry also creates other problem in waste management to our country. POFA was detected with high silica-alumina, being utilized as pozzolan which makes it as a good binding media similar to cement. In this paper, the specimens consist of 45 concrete cube size 100 x 100 x 100 mm at 3 different replacement level which were 0% as control specimen, 5% and 10% with two different techniques form which were powder and liquidation technique. The workability of fresh concrete properties was evaluated using slump test and flow table test and the performance of the hardened concrete was confirmed by cube compressive strength test at 3, 7 and 28 days. Based on the result, 5% POFA replacement using liquidation technique showed more workability compared to 10% POFA replacement. This phenomenon is due to the liquidation at POFA that acts as a liquid lubricant which can easily blend with cement component. However, concrete with 5% POFA using powder technique gives better result on the concrete performance. Powder technique shows better enhancement in strength as compared to liquid is due to the interaction between the raw POFA that's creates better bonding as compared to the POFA which was filled with water in liquid forms.

This study involves producing activated carbon from Ceiba Pentandra seed by using a physical activation method to adsorb Cu(II) from synthetic wastewater. Ceiba Pentandra seed was carbonized and activated using CO₂ using a microwave heating process. The process was optimized using Design-Expert version 11. The interactions between different process conditions towards the Cu(II) adsorption were analyzed. The optimum radiation power, radiation time and CO₂ flow were found out 264 Watt, 4 minutes and 100 cm³, respectively for the maximum Cu(II) removal.

Shear strength parameter is a crucial in designing the rock mass structures such slope and tunnel. Stability of rock mass structure is affected by apparent joint sets and discontinuities present in the rock mass especially when the joint interfaces degraded and physically altered due to weathering effect. The weathered condition imposed on joint surface importantly play the role to control the shear strength characteristic and sliding behaviour. A comprehensive study and focussing on effect of weathering grade to the rock joint surface particularly for granite type of rock was introduced. A set of granite samples were collected from a quarry then been classified into respective grade of weathering based on surface hardness by using Schmidt rebound hammer and rock material density by using PUNDIT test. The standard laboratory testing of direct shear test that accordance to ISRM suggested method were carried out on jointed block samples with different grades of weathering. Detail assessment on rock joint samples were evaluated to characterize the physical appearance of different weathered joint surface condition. The rock joint surface assessment made based on Joint Roughness Coefficient (JRC) then been correlate with thin section petrographical results for justification with respect to mineral composition contents. As the result, the shear strength of weathered rock joint significantly influenced by the weathering grade due to changes of microstructure behaviour of the granite. Moreover, the lower grade of the granite sample has low frictional resistance force to against the sliding, hence indirectly produced low shear strength of the rock joint.

This study deals with the effect of water on the tropical weathered granite and sandstone rock characteristics. Water act as an agent in the weathering process that lead to the weakness of the cementation and bonding condition. The process of wetting and drying are able to take place with the presence of water inside the rock microstructure, then further created the numbers of micro-pore which contributing to weakens the rock structure. Thus, this study is focusing to analyses the effect of the presence of water on the mechanical and dynamic properties of granitic rock depending on its weathering degree. The interaction between water and rock was observed through the water-rock interaction test by using saturation and caliper method, where all the rock samples, totalling 81 samples allowed to experience the wet and dry conditions for 21 days, 56 days and 90 days. Uniaxial compressive strength test, indirect (Brazilian) tensile strength and point load tests were conducted to determine the strength of the rock. Meanwhile, P-wave velocity test was conducted to measure the wave velocity that able to penetrate through the intact rock. In conclusion, the increasing of weathering degree, will allowed the rock to absorb the water as their particles has not more tightly bonding. Therefore, it found that the strength of tropical weathered granite was decrease as the interaction with water causes the interlocking of the rock particles is reduces from the process of weathering.

The flexural behaviours of reinforced concrete (RC) beams incorporating steel and polypropylene fibres under four-point bending test is examined in this paper. A total of nine beam specimens were designed, cast and tested under flexural loadings. Three types of concrete mixture – plain, concrete with steel fibres and concrete with polypropylene fibres – were employed in this study. Fibre content is fixed at 3% by the weight of sand as sand replacement for both mixtures containing either steel or plastic fibres. Compression tests were also conducted at 7, 14 and 28 days for twenty-seven concrete cubes prepared using the three mixtures. Comparisons of results were done in term of compressive strength, ultimate flexural load and deflection capacity. The crack pattern and failure mechanism of RC beams subjected to four-point bending are discussed. Finally, the effect of steel and polypropylene fibres on the flexural behaviour of RC beams are justified.

Zeolite membranes possess well defined pore structures which able to separate gasses with high selectivity. The separation between adsorptive and non-adsortive gasses depends on the affinity of permeating gas molecules with the zeolites structures whereby different types of cations resides in the zeolitic framework will affect the permeselectivity of the membranes. Several efforts have been made to modify zeolite membranes in order to enhance their capability in gas separation by ion exchange process. Here, investigations were performed on the ion exchange process of zeolite NaY membrane with Ag⁺ cation at different concentrations (0.1M, 0.025M) and temperatures (ambient temperature and 80°C). The results revealed that temperature plays significant role in maintaining the morphologies of zeolite NaY membranes. Dealumination process was also observed to occur simultaneously with the ion exchange process. Overall, CO₂/CH₄ selectivity of the cation-exchanged NaY zeolite membranes increased by 100% with less CO₂ flux reductions were recorded by samples which had been ion exchanged with less concentrated ion exchange solution i.e. 0.0125M at ambient temperature. Nevertheless, CO₂/CH₄ selectivity decreased for membrane samples which had been ion exchanged at higher temperature (80°C) due to dissolution of the zeolite membranes layer.

In this study the content of phenol and 2,4-DCP (2,4-dichlorophenol) in synthetic wastewater was decomposed using the excitation technique of a mixture of waste liquid and air in a cold plasma Dielectric Barrier Discharge (DBD) reactor. The purpose of this study was to study the degradation process of organic compounds of phenol and 2,4-DCP liquid waste into simpler compounds. Plasma technology applied to the liquid-air mixture in the DBD reactor has the ability to oxidize and degrade organic synthetic wastewater into simpler compounds with relatively faster processing times without forming new waste compounds. Plasma air (excited air) will degrade wastewater by breaking the atomic bonds of synthetic wastewater compounds at high voltages between 220 - 330 V. The performance of the degradation process of synthetic waste can be known through analysis of phenolic compounds, hydroxyl and dissolved ozone, COD, and the final product. The parameters studied in this study are air gas flow rate 2 - 2.5 L/min, waste water flow rate 52 - 100 mL/min, plasma voltage between 220 - 330 V, and volume of waste water. This study also compared the degradation process of phenol and 2,4-DCP in cold plasma DBD reactor with the degradation process in multi-injection bubble column reactor. The removal efficiency of the process achieved 57.5% for phenol and 89.55% for 2,4-DCP.

The presence of phenolic compounds, such as phenol (carbolic acid or phenylic acid) and 2,4-DCP (2,4-dichlorophenol), in trace amounts in the agricultural environment and in chemical industries wastewater has been considered a potentially large risk for the environment and human health. Therefore, it is very important to develop effective techniques for removing phenolic compounds in wastewater. This research was conducted specifically to observe the effect of temperature of ozone production in the ozonation process to remove phenol and 2,4-DCP in the agricultural aquatic environment and industrial wastewater. This experimental study was conducted using a semi-continuous multi-injection bubble column reactor with initial concentrations of phenol and 2,4-DCP 50 ppm for 60 minutes ozonation. The effect of parameters namely, waste water flow rate, air flow rate, pH of the solution, and temperature were evaluated and optimized. Degradation efficiency, COD concentration, hydroxyl radical concentration were also monitored. It was found that the degradation efficiency at room temperature and low temperature (cold conditions) of phenol were 98.79% and 98.22%, respectively, while 2,4-DCP degradation at room and cold temperatures was 99.83% and 99, 99%, respectively.

Oil palm (Elaeis guineensis) leaves extract is capable of acting as reducing and stabilizing agents to reduce and recover silver from simulated silver electroplating wastewater by chemical reduction method. First, Plackett-Burman design (PBD) was used to evaluate six factors that affecting silver biorecovery process. From the PBD analysis, only four factors were found to be significant. In order to maximize the biorecovery process, the significant factors were further optimized using response surface methodology (RSM). The optimum conditions were found to be 50% (v/v) of palm leaves extract, 1975 mg/L of initial silver ions concentration in wastewater, pH 7.5 of reaction medium and 70 °C of reaction temperature yielding 93.30% of silver being recovered. Characterization of the biorecovered solid particles revealed that elemental silver was successfully reduced and recovered from the wastewater with sizes ranging from 20 to 60 nm. On the other hand, characterization of the palm leaves extract revealed that hydroxyl and carboxyl groups compounds act as reducing agents to reduce silver ions into zero-valence silver atoms while polysaccharides, carboxylic acids and proteins act as stabilizing agents to cap and stabilize the silver solid particles formed.

In Malaysia, the productions of waste from various sources keep increasing annually. This problem can cause our nation to face serious problem regarding with the process in handling waste handling process at landfill. By recycling agricultural waste is the one of effective method to reduce the waste damping on landfill. The agricultural waste such as eggshell and coconut shell not commonly being used as stabilizing material as lime and cement in pavement design, but the mineral composition contain shows their own ability to strengthen the weak subgrade soil. Thus, the aimed for this study is to investigate the effectiveness mixture of eggshell powder (ESP) and Crushed Coconut Shell (CCS) on soil performance for subgrade layer. The combination of constant 3% ESP with the various percentage of CCS, 2%, 4%, 6% and 8% is evaluated by conducting Standard Proctor Test (SPT) and California Bearing Ratio (CBR) test. The results obtained shows the maximum CBR value achieved at 4% of CCS along with constant 3% ESP.

The experimental works involved the preparing of composite edible coating containing chitosan, starch, and glycerol to improve the shelf life of fruits. In this study, the number of raw materials was varied to determine the effect of each amount of raw materials towards the value of spreading, adhesion and cohesion coefficient on the fruit samples. The surface tension characteristic of the coatings is important for predicting the stability of the coatings during storage. 1.5 (% w/v) content of chitosan in coating solution was the best amount of chitosan to be used in formulating the chitosan-starch composite edible coating formulation while 2.0 (% v/v) amount of starch has got the nearest value to zero of spreading coefficient W_s, which make it the best formulation to be chose. Glycerol of 0.25 (% v/v) was used in formulating the starch composite edible coating formulation.

Batik industrial textile waste water effluent if improperly disposed to the catchment can cause the water pollution that will endanger human health and the environment. The contaminants discharge in the dye processing causes the water pollution. Banana peel is a potential agriculture waste that can be used to reduce the concentration of color from synthetic dye effluents. This study is aim to determine the potential of banana peel as agricultural waste adsorbent for Methylene Blue (MB) removal at different contact time (15minutes, 30 minutes, 45 minutes, 90 minutes, 120 minutes, 150 minutes, and 180 minutes) and different adsorbent dosage (0.05, 0.1, 0.15, 0.2, 0.25, 0.3, and 0.4 gram) and to develop kinetic model for Methylene Blue (MB) removal. The experiments were conducted at room temperature using batch study. As the banana peel dosage is added from 0.05 g to 0.4 g in 100 ml of Methylene Blue solution, the percentage of MB solution removal also increase from 34.69 % to 86.88 %, indeed due to the increase in phenolic compounds adsorption rates. The adsorption process reached the optimum contact time at 150 minutes with MB solution removal of 86.22 %. The kinetic data obtained specified that the data follow closely the pseudo-second-order. It is concluded that banana peel can act effectively as natural adsorbent in treating Methylene Blue (MB) from batik textile wastewater effluents.

Mineral carbonation is a process where carbon dioxide (CO2) is converted into solid carbonates. The product of mineral carbonation is obtained when CO2 is being contacted with alkaline earth metals, such as calcium and magnesium. In this research, the team focusing on producing precipitated calcium carbonate (PCC), as a solution to manage CO2 release which comes from high CO2 content natural gas field production. To make this process economically feasible, the team has researched obtaining valuable PCC quality which is marketable in various industries. The quality mainly measured in terms of particle size, where the particle size will determine the application of the PCC. This study investigates the effect of feed solution retention in reactor towards PCC particle size, using continuous mineral carbonation system. In this system, Milk of Lime, which is Calcium Hydroxide (Ca(OH)2) solution used as feed. To produce this solution, 7 g/L Calcium Oxide (CaO) is suspended in deionized water and stirred. This solution is injected in the range of 0.8 L/min to 1.2 L/min into pressurized CO2 in the range of 10 bar to 80 bar. The retention time is varied by using mechanically modified reactor inlet cap, where the feed inlet time is delayed by elongation of feed injector inside the reactor by 15 cm (NEWCAP). Particle size of the product was analyzed by using Malvern Mastersizer 3000. Experimental data show that by shortening the feed solution retention time inside the reactor, will produce smaller particle size. Using the unmodified reactor inlet, the obtained product particle size ranging (D50) from 15 micron to 25 micron. On the other hand, using NEWCAP reactor inlet the obtained particle size ranging (D50) from 8 micron to 20 micron.

The internal combustion engine has an intake system that preparing sufficient charges for the engine cylinder. This study is focused on the effect of different intake geometry on the intake pressure and brake mean effective pressure to correlate volumetric efficiency and brake power performance. Five types of intake geometry are simulated by a one-dimensional computational tool. Through the simulations, it can be found the maximum volumetric efficiency predicted by taper design at 1.15 bar of intake pressure and 12.50 bar of brake mean effective pressure when volumetric efficiency reached to 115% and brake power of 19.5 kW. The baseline intake and bellmouth intake showing intake pressure at 0.91 bar and 0.94 bar except for both single bend intake and s-bend intake indicated 0.92 bar intake pressure and 9.35 bar of brake mean effective pressure. The measurement of intake pressure and brake mean effective pressure over various intake geometry displayed a significant influence on the volumetric efficiency and brake power trend.

The concept of supercritical CO2 mineral carbonation reaction was firstly proven and demonstrated in the laboratory scale using a 100cc high pressure PVT recombination chamber. Successful proof of concept led PETRONAS to scale up this reaction by developing a working prototype mineral carbonation reactor with the intention of demonstrating the continuous operation of the supercritical CO2 mineral carbonation process. The setup comprising of a feedstock tank, a high pressure liquid pump, a 0.8L high pressure tubular reactor, injector spray nozzle was thoroughly tested to understand the feasibility and robustness of the prototype reactor design and configuration. Another purpose was to study the effect of varying parameters such as reactor pressure, feedstock injection flow rate and compositional effect of methane in carbon dioxide gas reactant to the properties of the precipitated calcium carbonate produced from this process scheme. In summary, the setup was successful to demonstrate the concept of continuous supercritical mineral carbonation reaction up to 1.5 litre/min feedstock injection flow rate. The effect of reactor working pressure and feedstock injection flow rate was the main factors determining the properties and quality of precipitated calcium carbonate produced. Particle size distribution of the calcium carbonate precipitates produced from this setup averaged approximately 6 microns in size. Other parameters such as gas composition and recycling of carrier fluid sucrose have less effect on the properties of the product.

The challenge of increasing ridership in public transportation has never been easy. Private vehicles often provide a greater opportunity to travel in rural areas and small cities with low traffic density but not in high-density cities. This paper attempts to identify the factors that affect myBAS service operation in Perlis and provide ratings on its headway patterns. The study focuses on the passengers of myBAS in Perlis and the selected routes were T101, F101, and CF109, with the most access to popular cities. Atlas Ti. (Version 7.0) was used for data analysis and a group of 11 factors affecting service operation were identified. Subsequently, an observation was also made by comparing the schedules published by the operator. Based on United States Highway Capacity Manual 2010 (USHCM 2010), the findings revealed that LOS for headway pattern during peak hour on route T101, F101 and CF109 is in the range of E (30 min to 60 min) with 1 bus arriving per hour. The findings also show "Service available during hour" and by improving the LOS of bus headway, the operator may increase ridership among local citizens. This study will benefit the local authority in achieving the status of the sustainable city towards 2030 in line with the United Nation's declaration which focuses on green and healthy cities by having good mobility management and promoting better transportation planning as well as increasing ridership among citizens.

Aluminium matrix composites (AMCs) through the medium of in-situ counteraction has crop up under the name of preference contributively prior to lay out weak point as well as defects reside within ex-situ MMC. In contemporary work, aluminium-copper-zirconium diboride (Al-Cu-ZrB₂) composite have been plug through in-situ reaction which promote mechanical abilities on top of dispersion strengthening together with grain refinement accessed by continuation of particular particulates inside the melt for the time being of solidification. Aluminium-copper (Al-Cu) reinforced which was surrounded by various proportion of zirconium diboride (ZrB₂) which were 0, 3 and 6 wt. % synthesized applying in-situ fabrication at 800 °C of molten Al-Cu alloys by inorganic salts potassium hexaflourotitanate (K₂ZrF₆) mixed with potassium tetraflouroborate (KBF₄). The amalgam itemized using Potential-Dynamic Polarization (PDP) test on suitably segment which were metallographically qualified surface to criticize and inspect the corrosion rate itself. Microstructural investigation discovered the homogeneous and persistent allocation of second phase particles, clean interface together with favourable bonding. It is promoting that zirconium diborate (ZrB₂) molecules are altogether in nano size amidst hexagonal either tetragonal shape, yet minor molecules in micron size were also noticed. For that intention, composite synthesized using in-situ techniques indicated homogeneous disposal of reinforcing influenced to be superlative associated within pure interface al over metallic matrix. Outcome of dissimilar ZrB₂ percentages all over surface morphology, surface roughness, grain size, crystalline texture and of Al-Cu alloy were also inspected. Results displayed grain size drop off upon an increase of ZrB₂ content in the Al-Cu alloy. Furthermore, the surface roughness was seen to decrease alongside greater ZrB₂ concentration of the deposited alloy.

Copper Cu (II) is one of the toxic contaminants of heavy metal in wastewater. The performance of activated carbon (AC) produced from Cucurbita Pepo.L seed as an adsorbent for the removal Cu is presented in this paper. The preparation of CPSAC uses 2-step physical activation assisted by microwave and CO₂. The effect of contact time and initial concentration were examined. The batch study was conducted, and the data shows that the absorption was plotted better by using Langmuir isotherm.

This research investigated numerically the effect of the equivalence ratio on the temperature distribution in an industrial non-premixed flat flame burner with methane as the fuel. The burner configuration is a wall-fired one to produce a flat flame with a large cross-sectional area to effectively radiate heat to tubes contained in a pyrolysis furnace. The temperature distribution was predicted by using a phenomenological model consisting of mass balance, energy balance and momentum balance with computational fluid dynamics approach. Fluid flow was explained by the k-ε turbulent momentum balance, and the reaction rate was approached to eddy dissipation model. Simulation results show that the change in the equivalence ratios affects the temperature distribution so that this variable needs to be adjusted with certain considerations for pyrolysis process.

This paper presents the intensity crack zones of reinforced concrete (RC) beam under monotonic loading in conjunction with acoustic emission (AE) monitoring. Five RC beam size 200 mm x 300 mm x 1500 mm were prepared and tested. Due to similar pattern in term of the crack pattern and the analysis, only one beam was presented in this paper. The intensity crack zones were performed by mean of historic and severity indices at sensor 6 (CH6) and sensor 7 (CH7). The plot in the intensity crack zone was based on the crack mode performed during testing. As a result, the progression of the crack was well-matched with the plots in the intensity crack zones. In a nutshell, the data obtained from the AE signal and analyse using intensity analysis, it can be used to classify damage in the RC beam.

Wastepaper sludge ash (WSA) is generated during the recycling of paper, which is an industrial by-product can induce pollution to the environment. Due to its effect related to pollution, a generic review on its application is required. Despite many researchers conducted in the world to resolve the application of WSA as a sustainable material, the effects of WSA as a cementitious material in its application is still limited assess. Hence, this paper presents a generic review on the effect of WSA as a cementitious material. The generic review on WSA in term of its physical properties, chemical properties, reactive properties and application of WSA in the industry was carried out. From the review on WSA properties, it is found that the WSA has good potential as one of the important materials in the construction industry especially in the production of concrete, brick, mortar, soil stabilizing additive, rigid pavement and controlled low-strength materials (CLSM).

Physalis minima linn is a plant under the Solanaceae family having secondary metabolites with distinct biological activities. The total phenolic, total flavonoid and antioxidant activity on different parts (leaves, whole plant, stem, roots and fruits) of Physalis minima linn were analyzed using Folin-Ciocalteu method, aluminium chloride colorimetric method and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. Results demonstrated that leaves extract exhibited as the highest value of total phenolic content of 1125.42±14.60 mg of gallic acid (GAE) equivalent per gram of plant (dry extract). The low value of IC₅₀ indicated that leaves, whole plant and fruits can be deemed as a good candidate for natural plant sources of antioxidants with high value of antioxidant activity.

In this research, removal of cyanide and COD in tapioca starch wastewater by ozonation and adsorption using GAC examined. The method effectiveness evaluated from percentage of cyanide and COD degradation and ozone mass balance. Effect of degradation method, pH and ozone dose was determined using synthetic wastewater with initial cyanide concentration of 30 ppm and COD concentration of 1000 ppm. Using ozonation adsorption with pH 10 and ozone generation rate of 303 mg O₃/h, 91.75% cyanide and 68.94% COD from synthetic wastewater was removed in 1 hour. Tapioca starch wastewater with cyanide concentration of 8.5 ppm and COD concentration of 4625 ppm treated using the same operating condition. Using this method, 87.06% cyanide and 43.23% COD was removed.

Acoustic emission (AE) has been widely used for monitoring of the structure performance. However, identification of structure's characteristic is still limited assess. Hence, this paper presents the characteristic of AE of different thicknesses of reinforced concrete (RC) slabs. Two different thicknesses of grade C25/30 RC slabs which are 125 mm and 175 mm were prepared and designated as S125 and S175, respectively. The slabs were designed based on Eurocode 2 with the size of 500 mm width x 1000 mm length were tested under three-point loading in conjunction with the AE monitoring. The maximum loads of the slabs were identified. The acoustic signal strength was analyzed and discussed. It is found that the maximum load of the RC slabs is increased as the thickness of the slab increases. Moreover, the signal strength of S175 is greater than the S125. Hence, this study is beneficial to provide factual data on the maximum load and AE characteristic of different thicknesses of slab.

The potential use of banana stem adsorbent has been investigated via batch adsorption experiment. A series of batch experiment was carried out to determine the effect of various adsorbent dosage ( 0.2 – 1.4 g) and various contact time ( 15 – 120 minutes). Analysis on adsorption isotherm was done using Langmuir and Freundlich model. In addition to it, the behaviour and mechanism of adsorption was analysed using kinetic model, namely Pseudo-first order and pseudo second order kinetic. The result shows that more than 90% of colour was removed at optimum dosage of 1 g of banana stem adsorbent in 100 mL synthetic dye at optimum contact time of 90 minutes. Analysis of isotherm models showed that the adsorption of colour by banana stem adsorbent was fitted to Freundlich with coefficient of determination, r¹ of 0.917. Adsorption kinetics of colour showed that Pseudo-second order fit better (r² = 0.99) than Pseudo-first order (r² = 0.94) kinetic model. From the result, it was indicated that the adsorption of colour occurred by multilayer on a heterogeneous surface of the banana stem through the chemical reaction process. As a conclusion, the use of banana stem adsorbent has good potential for colour removal in textile wastewater treatment because of low cost of the media. Thus, it is an alternative to overcome problems related to an excessive of colour in dye wastewater treatment plant.

The development of supplementary cementitious materials (SCMs) has become essential in the advancement of low-cost construction materials for production of self-sufficient housing especially in developing countries. The use of these SCMs as admixtures not only improves concrete properties but protects and conserves the environment by saving energy and natural resources. Thus, studies have been conducted to find the suitability of combination of sewage sludge ash and rice husk ash to replace cement partially in conventional concrete. The effects on the nature of concrete exhibited mechanical properties of concrete such as compressive strength from a combination of sewage sludge ash and rice husk ash at different proportions. Sewage sludge ash (SSA) and rice husk ash (RHA) are used as partial replacement of cement for 10%, 20%, 30%, 40% and 50% in the concrete. The samples had been tested with compressive test to compare with normal concrete (OPC). There was an increment compressive strength of concrete at 10% amount replacement SSA and RHA, but the compressive strength declined when the amount replacement SSA and RHA are developing more than 10%. In addition, the concrete also showed increasing of compressive strength within the additional curing period, which was 7 days, 14 days and 28 days.

Steel has been widely known as the essential material for reinforcement. However, many researches have been conducted in order to find an alternative sustainable material to replace steel. In this study, bamboo has been chosen to replace steel as reinforcement is introduced as one of the alternative material for reinforcement of concrete. The Semantan Bamboo (Gigantochloa Scortechinii) splint with a size of 20 mm x 10 mm (Thickness) was used as the main reinforcement. Three samples of two-way concrete slabs were prepared with a dimension of 1200 mm x 1200 mm x 100 mm. One sample will be constructed without reinforcement, while the remaining two samples will be reinforced with 1.5%, 2.5%, 3.5% and 4.5% of bamboo. All the samples will undergo concentrated punch loads and control slab without reinforcement. The results show that the maximum punching shears that the slabs can sustain more 60 kN. The slabs fail by the cracking of concrete at the bottom of the slab under the concentrated load.

Industrially, a low-density polyethylene (LDPE) is characterized based on their Melt Flow Index (MFI). In numerous publication, LDPE's MFI is correlated to its average molecular weight (Mw). An overview of modeling studies on LDPE reactors available in the open literature indicates significant discrepancies among researchers for the correlation of MFI-Mw, therefore a research to produce reliable correlation need to be carried out. This research gathers various experimental and industrial data of different LDPE product grades. Empirical correlations between MFI and Mw are developed and the analysis on the MFI and Mw relation is addressed. The percentage of error between the model prediction and industrial data varies from 0.1% to 2.4% which can be considered minimum. The nonlinear model obtained indicates the competency of the developed equation to describe the variation of industrial data, thus allowing greater confidence in LDPE's MFI prediction.

This study aims to investigate the effect of impactor on the behaviour of CFRP with toughened interlayers when subjected to low-velocity impact. CFRP with toughened interlayers is different from a conventional CFRP laminate since it enhanced the toughness of CFRP laminate. In this study, CFRP with toughened interlayers laminate was subjected to low velocity impact by using a drop weight testing apparatus developed in the laboratory. Four sizes of impactor head diameter were used with three different masses. The impactor was suspended at a specified height and released for a free fall drop. The impact event was then reproduced numerically. Based on the results, it was observed that the degree of damage was increased as the mass of impactor increased. However, smaller head diameter of impactor produced greater damage. Hence, smaller contact area produces greater local deformation as opposed to larger contact area that generates global deformation. Numerical analysis is also capable to reproduce the impact event.

Rotating Disc Contactor (RDC) columns are one of the extractors that used for liquid-liquid extraction. It has an extensive application in various industries. The performances of these columns indicate that they are more efficient and possess better operational flexibility. However, there is still some improving that researchers can do to enhance the performances. This paper presents Support Vector Machine (SVM) and Neural Network (NN) modeling in prediction of concentration of dispersed phase outlet in RDC column. SVM is an exciting Machine Learning technique that learns by example to sign labels to object and can be used for regression as well as classification purpose, while NN is widely used as an effective approach for handling non-linear data especially in situations where the physical processes are not fully understood. The mean square error (MSE) is calculated to compare the result between the two models. The analysis shows that both SVM and NN modeling can predict the concentration of dispersed phase in RDC column but the SVM approach gives better result than the NN approach. Both modelling systems offer the potential for a more flexible and less error in forecasting. Thus, it can help to save time and reducing cost in conducting experiments.

This paper presents the investigation on severe damaged-RC beams repaired with epoxy injection and retrofitted with carbon fibre reinforced polymer (CFRP) on the soffit subjected to monotonic loading concurrent with acoustic emission (AE) monitoring. Ten beams were prepared namely reference beam (S1C) and damaged RC beam repaired with epoxy injection and strengthened with CFRP (S3B). The load, signal strength, average frequency-RA value and crack modes were analysed and discussed. As a result, the S3B produced highest maximum load and AE signal strength compared to S1C. In a nutshell, the AE can be used to identify the integrity of the damaged-RC beam repaired with epoxy injection and retrofitted with CFRP.

High demand of recycling waste materials are able to solve disposal problem which created opportunities for researcher to use it in their product. Waste clay brick dust is one of the material can be improvised to be tested for the performance of porous asphalt pavement towards rutting problem. In this study, crushed dust of clay brick was used in porous asphalt mixture as mineral filler. 15 samples were produced in different proportions (4%, 4.5%, 5%, 5.5% and 6%) of bitumen content and each proportion have three samples. The optimum bitumen content (OBC) obtained was 4.75% for modified and 5.9% for conventional porous asphalt. Rutting Test was then tested to evaluate the performance of porous asphalt after being modified with clay dust and compared with conventional mixture of porous asphalt. Modified mixture showed a slight higher in rutting depth of 2.2 mm compared to the conventional mixture of 1.6 mm. This means that modified mixture is less in rutting strength. However, the drain down test showed that modified samples are more intact between binder and aggregate and able to sustain in high temperature. Further modifications are required to enhance rutting strength for modified mixture.

The environmental problem due to plastic waste had become serious because it could not be recycled neither be degraded naturally by microbe in land. Thus, in the present study, a bioplastic was produced based on cassava starch as the matrix and cellulose nanocrystal (CNC) from Mangosteen peel as reinforcing filler. The CNC was added into the bioplastic with varied concentration at 1 g (BP2), 2.5 g (BP3), 5 g (BP4) and without CNC as BP1. The isolation of CNC followed series of steps (delignification, bleaching, hydrolysis and sonication) before added to the matrix. The effect of CNC addition towards mechanical properties was determined using universal testing machine (UTM) and analyzed using Fourier transform infrared (FTIR) spectroscopy. Results showed that the FTIR analysis confirmed an absorption pattern of cellulose in the starch/CNC bioplastic matrix whereas the effect in tensile strength, tensile modulus and elongation at break were compared to the pure bioplastic without CNC. The highest tensile strength peaked at 1.93 MPa while Young's modulus at 26.82 GPa was observed for BP1. On the contrary, the addition of CNC fillers to the bioplastics increased the elongation at break and the density while the elongation at break reached the lowest percentage is 13.93% and the lowest density value is 952.5 kg/m³. Based on overall observation, this study proved that the addition of CNC on the other hand the mechanical properties showed the different result.

The rising of CO₂ concentration in atmosphere become global concern due to its effect to the global warming. One potentially economical for CO₂ capture is through adsorption using solid sorbents. Silica gel has potential to adsorb carbon dioxide with modification of silica gel with amine groups which provide specific adsorption sides for carbon dioxide adsorption. Therefore, a study of impregnated silica gel with amine for carbon dioxide adsorption was done. A series of characterization was made between raw silica and impregnated silica with amine. Based on the results from Iodine Test Analysis and DSC characterization, it can be stated that the modification of Raw Desiccant Silica Gel (DSG) which had been modified with Aminopropyltrimethoxysilane (APMS), 95% had the highest possibilities of percentage to absorb CO₂ from the environment with iodine value of 2736.85 mg/g that indicate the porosity and surface area of the adsorbent is higher. Amine 1A consist of 17.84 % of carbon, 5.41 % of hydrogen and 6.44 % of nitrogen. For FTIR result, Amine 1A has Si-O-Si stretching, C-C stretching, N-C stretching and C-N stretching due to the impregnation of amine to the raw silica gel. From DSC analysis, the higher the peak shows that water molecule bound to Amine 1A evaporated at a higher temperature of 92.4°C shows the highest porosity and have highest possibility as adsorbent for CO₂ adsorption.

Forward osmosis (FO) membrane has becomes a promising membrane technology due to its lower energy consumption and high salt rejection performance. However, in prolong application, FO membrane is susceptible to internal concentration polymerization (ICP) that reduce water flux through the membrane. Therefore, layer by layer (LbL) method was proposed to improve the FO performance. This study focused on the effect of fabrication method to cast thin film composite (TFC) membrane using SL method and LbL method. The membranes were prepared using interfacial polymerization technique and tested through salt rejection experiment. Theoretically, LbL method should provide high salt rejection value as it is good at controlling the structures and thickness compare to SL method. However, from the testing, the results showed that the salt rejection value of TFC membrane using SL technique is higher (97.17%) compared to LbL technique (73.33%). Thus, it is suggested, co-casting method should be used towards the TFC membrane for future studies due to its advantageous over SL and LbL method.

Since the ancient time, camphor's tree has been used as one of the traditional medicines to cure wounds. It is believed to have active component that can heal the wounds. Therefore, the present study was undertaken to prepared crude extracts of camphor leaves with different polarity organic solvents using a hot extraction (Soxhlet) and cold extraction (maceration) method and assessing the antioxidant activity by the spectroscopic. The dried camphor leaves were crushed into powder form (size - 250 μm) and subjected to extraction using different polarity organic solvents such as hexane, chloroform and ethanol to extract chemical compounds from the leaves. DPPH (2,2-diphenyl-1-picrylhydrazyl) method was used to determine the antioxidant activity due to its characteristics as a stable free radical and acts as an indicator of scavenging activity. Quantitative analysis found that all extract shown a significant antioxidant activity. The ethanol extracts resulting highest antioxidant activities than other extracts. The highest inhibition percentage (87%) was found in the hot extraction method extracts compared to chloroform (40.4%) and hexane (12%) extracts, meanwhile cold extraction resulting to lower inhibition percentage. The yield obtained from cold extraction is higher than hot extraction. However, it contains higher impurities as compared to hot extraction. These finding is proven that camphor leaves with high antioxidant properties is suitable for medicine composition, especially related to cure wounds.

The losses of β-carotene in crude palm oil (CPO) during bleaching process in the industry of oleo chemical bring apprehension because β-carotene is the most important vitamin A precursor that can helps to prevent night blindness, eye problems and skin disorders, and could enhance immunity and protects against toxins, colds, flu and infections.Yet, recovery of β-carotene can be done by adsorption using activated carbon. Accordingly, the study aimed to prepare activated carbon from palm kernel shell (PKSAC) by chemical activation and its application for β-carotene adsorption in CPO has been examined. Activation of palm kernel shell carbon was done chemically using Zinc Chloride (ZnCl₂) at impregnation ratio of 1:1 mass basis for 24 hours and carbonization was done at 500 °C for 30 min, 60 min, 90 min respectively called as PKSAC30, PKSAC60 and PKSAC90. PKSAC are characterized using ultimate analysis, Fourier Transform Infrared (FTIR) analysis and scanning electron microscopy (SEM). The capability of PKSAC to adsorb β-carotene was studied using n-hexane as a solvent. β-carotene adsorption test was carried out in a lab-scale batch adsorption reactor. SEM and FTIR analysis result revealed the PKSAC has fibrous morphology and indicates that raw PKS was successfully converted to carbon after activation process and was proven by spectra of previous researchers. For adsorption testing, PKSAC90 give the highest percentage removal of β-carotene, 69%.

Kapok predominantly utilized as an adsorbent in removing wastewater such as dye, oil and heavy metals. However, a comparative study between acid-treated and alkali-treated carbonized Kapok fibers has not been carried out in detail. In this study, as-made Kapok fibers were carbonized and subsequently undergo acid (HCL) and alkali (NaOH) treatment. The resultant treated Kapok fibers were characterized using Fourier transform infrared (FTIR) spectroscopy, Elemental Analyzer (EA) and Thermogravimetric Analysis (TGA). As-made carbonized Kapok fibers were tested with oil/water absorption model system. A reduction of band intensity at 1740 cm⁻¹ and 1245 cm⁻¹ occurred for NaOH treated sample compared with HCL. The composition of carbon in Kapok fiber increased after carbonization treatment using NaOH (62.42%) and HCL (66.15%) compared with untreated (0.17%). For oil/water absorption system, the result indicated that HCL-treated Kapok fibre was the highest absorption on 28.10 gg⁻¹ diesel, 27.28 gg⁻¹ petrol and 39.84 gg⁻¹ for used vegetable oil respectively in comparison with NaoH-treated and as-made carbonized Kapor fibers. In conclusion, modification of the surface of carbonized Kapok fibers could significantly alter its textural properties which could enhance its oil absorptive behavior.

Wastewaters generated from textile industry are mostly contained high concentration of dyes pollutant. Commercial dyes are difficult to treat due to their complex structure and synthetic origin. An untreated dye discharged through the wastewater system affect the environment. Most of the conventional methods that have been used for the treatment of dye-containing wastewater had resulted in varying degree of success. In the present study, corn stalk residue from the corn industry has been used to remove the Alizarin Yellow (AY) dye. The corn stalk was treated by hydrochloric acid (HCl) in order to improve the porosity of the adsorbent for the AY dye removal. The adsorption capacity and percentage removal of AY dye at varying adsorbent dosage, initial AY dye concentration and adsorption time onto acid treated corn stalk adsorbent sample was examined by using UV-Vis spectrometer. The percentage removal and adsorption capacity increases with the adsorbent dosage, initial dye concentration and adsorption time. Maximum AY dye percentage removal of 75.85% was achieved using 0.6 g corn stalk adsorbent at 20ppm AY dye concentration. The adsorption increases rapidly in the first 10 min to about 70% and extending the adsorption time do not further increase the adsorption of the AY dyes. Adsorption data were modelled using Langmuir and Freundlich isotherms. Both models adequately described the adsorption process with RL value of 0.049 (0<RL<1) for Langmuir and n value of 0.028 (n greater than 1) for Freundlich model which indicated that the adsorption was favourable. These results showed that acid treated corn stalk has the potential to be employed as an effective absorbent for the removal of dyes from wastewater.

Water-in-oil-in-water (W/O/W) emulsion system in Emulsion liquid Membrane (ELM) consist of three main phases which are membrane phase, internal phase and external phase. However, ELM performance is reported to be heavily affected by the emulsion stability. Instability of emulsions occurred as a result of metastable colloids that are made of two immiscible liquids, where one being dispersed in the other with the presence of surface-active agent. Membrane breakage was identified as one of the causes of emulsion instability. This research work focuses on identifying best condition that records minimal breakage hence, high efficiency of solute removal can be anticipated. Influence of homogenization time and speed, carrier concentration and surfactant concentration on membrane breakage were investigated. Data recorded shows that the emulsion needs to be homogenized at 8000 rpm for 15 mins to obtain minimal breakage of membrane. On top of that, membrane phase consists of 4 wt% of carrier (D2EHPA) and 4 wt% of surfactant (Span 80) dissolved in kerosene is needed. 0.14% of breakage was recorded at the conditions mentioned.

Coal Bottom Ash (CBA) is normally associated as a by-product from the thermal power plants. Due to the current situation where the power plant is facing an increase in the production of CBA at an alarming rate reaching up to hundreds of thousands of tonnes in Malaysia alone, without known economic value CBA commonly ends up in ash ponds. As sustainable solid waste management has become a growing concern, this research present the recent development achieved on the utilization of CBA as partial replacement of cement in concrete bricks manufacturing. The influence of different amount of CBA on the water absorption, compressive strength performances and UPV test on bricks are presented. With the addition of CBA as a partial replacement of cement also causes an increase in physical performance compared to regular bricks. As a conclusion, the bricks produced passed the required value of typical commercial bricks for water absorption, ultrasonic pulse velocity (UPV) and compressive strength test for industrial purposes. Hence, incorporating CBA in construction materials will significantly reduce the dumping of the by-products in landfills and thus reduce the adverse effect towards the environmental.

Sewage sludge is regarded as a residue produced from municipal waste water treatment system. This waste is often used in low-value applications such as composting and incineration or disposed in landfills. Such practices posed many potential environmental hazards due to high levels of pollutants in the sludge. Sewage sludge is also a potential energy and currently received renewed attention for potential recovery of bio-oils and biochemicals through thermochemical conversion route. Hydrothermal liquefaction is a promising green method for conversion of sewage sludge. Hydrothermal liquefaction of sewage sludge were investigated at different temperatures (250°C, 300°C, 350°C and 400°C) and 1 hour reaction time. Experiments were carried out in a 10 ml stainless steel bomb reactor. The initial calorific value of sewage sludge was 12.36 MJ/kg. It was found that significant bio-oil yield of 52.23% and 48.25% were obtained at 350°C and 400°C respectively. Overall, the bio-oil yield increases with temperature up to critical temperature of water. It was clear that synergetic effect on the yield of liquid and solid were observed due to extended biomass fragmentations and depolymerization when reaction temperature was raised.The bio-oils produced from liquefaction of sewage sludge at 350°C contained an abundant number of ester based compounds, highlighting its potential as biofuel.

Development requires new findings and innovative science to support. This research aims to study the simulation of soft ground improvement by comparing the soil strength after mixing with pozzolanic and fibrous additive such as Palm Oil Fuel Ash (POFA) and Palm Oil Fibre (POF) were chosen due to its redundancy found as industrial waste material. The soft soil sample collected was added with 0%, 5%, 10%, 15% and 20% percentage of additives by weight respectively. The soil sample used was from the soil that passed through sieve size of 0.425 mm. The data and analysis show that POF treated soil has a higher optimum moisture content and greater shear strength than the POFA treated soil.

Lightweight polyurethane (PU) foam is an alternative ground improvement method to resolve soft ground problem. In this study, Rowe Cell laboratory test is executed to determine the consolidation settlement of marine clay soil improved with polyurethane foam. The ground improvement is carried out by excavate the soft soil at shallow depth and replace with polyurethane foam. The performance for different thickness of PU foam as a ground improvement is evaluated. The comparison is made between partial replacement of PU foam on saturated marine clay and water in order to determine the buoyancy and uplift behaviour of the ground improved with lightweight PU foam. The percentage thickness of PU foam to soft clay layer and water varies from 20% to 80%. The correlation between PU foam thickness coefficient and compressibility index, Cc value for PU foam partial replacement on water and saturated soil are adopted in this study with the respective equations. The settlement reduces significantly with the increase of PU foam thickness for both soil and water conditions.

The buoyancy of lightweight polyurethane (PU) foam as a ground improvement is of important aspect to be investigated to ensure the stability of the founded structure. Constant Rate Strain test (CRS) was carried out to evaluate the buoyancy behavior of PU foam in water and to determine the effect of different water content of the marine clay to the settlement and uplift in short term undrained condition. The percentage thickness of PU foam to soft clay layer and water varies from 10% to 80%. The buoyant force of PU foam to immerse at the water surface depends on the thickness of PU foam that displaces the water. On top of that, water content in the soil has a crucial effect on the buoyancy of PU foam. For PU foam partial replacement on water, the downward displacement is very less compared to the settlement for PU foam partial replacement on marine clay soil due to higher buoyant force produced in the earlier condition. However, the settlement for improved condition of marine clay reduces significantly compared to the condition of existing condition. In addition, the reduction in soil weight as part of the soil is replaced with lightweight PU foam assist to reduce the overburden load imposed on the soil. Therefore, settlement reduces significantly with the increase in PU foam thickness. The verification of the buoyancy test results was done using finite element model PLAXIS 2D.

Construction waste generation is one of the challenging tasks that related to the materials used at site. Brick waste (BW) is also part of the waste generated in construction sites. This paper determines the brick waste generated in construction stages and conducts linear regression analysis for the amount of brick waste generated. The brick waste management practices are also revealed in this study. The method used in this study was Linear Regression Model. The regression model established based on the sample data reported an R2 value of 0.78; therefore, the model can predict approximately 78% of the factor (area) involved in brick waste generation. Specifically, the prediction model is focusing on the relationship between the area of work and the amount of brick waste generated. Moreover, the linear regressions can be applied as tools to predict the brick waste generated at construction sites and as a tool for the contractor to track the brick waste sources in the future.

This research focused on fabrication of castor-based PU grout (CPUG) using castor oil with OH value of 161 mg/KOH/g and MDI with NCO content of 31%. The effect of different NCO/OH ratio on the foam reaction time, density, rheology, morphological and mechanical properties were investigated. The result shows that the rise time of CPUG decreased while tack free time increased with the increased of NCO/OH ratio. Morphological properties shows that CPUG consist of closed cell of foams and the diameter of a single cell foam decreased with the increased of NCO/OH ratio. The apparent density, rheology index, flexural strength, flexural modulus and compression strength of CPUG increased with the increasing NCO/OH ratio. CPUG's apparent density was in the range of 230.23 kg/m³ while rheology index of CPUG was between 1.74 to 2.43 cm/g. Both values obtained were in the range of industrial PU grout's density and rheology index (214 kg/m³ & 1.48 cm/g). CPUG4 give the best flexural and compression strength with a value of 11.01Mpa and 2Mpa respectively. Flexural and compression strength of CPUG were tantamount to the industrial PU grout's properties which the average of flexural strength and compression strength were about 7.4MPa and 2MPa respectively.

The aim of this study was to examine issues of benefits (B), potential risks (PR), government support (GS) and attitude (AT) that influence the acceptance (AC) of nanotechnology in Malaysia. Respondent were selected based on purposive sampling and generally they represent the various social groups in the country (n=1207). The findings of the study provide a strong support of the relationships, which theorizes for the roles played by each determinant, either positively or negatively. Almost equal results were obtained to determine nanotechnology acceptance between benefits, potential risks and government support.

Silver nanoparticles (AgNPs) were synthesized by green biological technique utilising kyllinga brevifolia extract (KBE) as reducing agents. The KBE was also found to be a good capping as well as stabilizing agent. The size, shape and dispersion of AgNPs were evaluated and compared with the results from the literature survey. The TEM image showed that KBE-driven AgNPs have quasi-spherical shape are highly dispersed with an average particle size ~17.64 nm. The catalytic activity of KBE-driven AgNPs on reduction of methylene blue (MB) using sodium borohydride (SB) was analysed using UV-vis spectroscopy. The MB removal was achieved 100% at pH 8-10. The efficient removal is proposed to be due to the process of reduction via electron relay effect.

Biodiesel or fatty acid methyl ester (FAME) obtained via esterification process is an alternative for industrial and transportation fuel. In this study, chromium-titanium mixed oxides catalyst synthesized via sol-gel method was used to catalyse the esterification of palm fatty acid distillate (PFAD) to produce FAME. Esterification was conducted in a batch reactor. The effects of reaction temperature, methanol to PFAD molar ratio, reaction time and reusability of catalyst were studied. Reaction conditions yielding the best performance of 89% FAME content were reaction temperature of 160°C, methanol to PFAD molar ratio of 3:1 and reaction time of 3 h. The catalyst can be reused for 3 times with 20% performance reduction between the first run and the third run. The results revealed that the mixed oxides of Cr-Ti is a potential heterogeneous catalyst for use in the esterification of high acid value feedstock of PFAD.

This paper presents a self-tuning fuzzy logic controller plus PID controller that applied for essential oil extraction process. The most popular technique in extraction essential oil is using steam distillation. This method is lack to the process requirement and also towards parameter change. In order to regulate the steam distillation at desired extraction condition, the controller needs to integrate to the plant. By using auto regressive model with external input (ARX) model structure, the temperature of steam was successfully modelled with best fit 98.42%. This model was successfully representing the system during controller simulation work. There are several controllers that demonstrated in this project which are self-tuning fuzzy PID controller (STFPID) and conventional PID. Both controller will compare their performance in terms of system response which are percent overshoot (%OS), settling time (Ts) and also rise time (Tr). As the result, the STFPID with seven membership function gives the best performance compared to PID controller.

Drilling fluid plays an important role in ensuring smooth drilling operations. Application of ester based drilling fluid (EBDF) is desirable as it shows comparable performance to the conventional oil based drilling fluid (OBDF) as well as environmental friendly. The ester used as a base in the EBDF is usually derived from vegetable oils such as palm oil. In this study, methyl laurate (ML), methyl palmitate (MP), and isopropyl laurate (IPL) esters were used as a base in the EBDF formulation. Subsequently, their physical and rheological properties were determined. In addition, thermal stability of the EBDF was tested to estimate the maximum operating temperature for the EBDF application. Isopropyl laurate (IPL) based EDBF was found to have better rheological properties at standard test condition as compared to the other two esters used. The IPL based EBDF also showed improved viscosity at 90°C. Thermal stability test conducted on the IPL drilling fluid indicated that it is stable up to 150°C.

Gel dosimeter is a kind of radiation dosimetry medium that has been extensively applied in radiotherapy treatment. In this study, the samples of NIPAM-based polymer gel that possessed a good potential as 3D radiation dosimetry were fabricated. The samples of polymer gel were irradiated up to 18 Gy by using gamma irradiator with 60Co sources at a constant dose rate. Upon irradiation, the chemical changes in polymer gel were measured and evaluated by using a Raman spectrometer. Polymerization refers to an increment in Raman intensity at 815 cm-1, assigned for C-C stretching mode of NIPAM polymer gel, as the dose was increased. Consumptions of the co-monomers refers to a decrement in Raman intensities at 1025 cm-1 and 2353 cm-1 assigned for C=C stretching modes of NIPAM and BIS respectively, as the dose was increased. Result showed that following irradiation, the amount of carbon single bonds increases while the amount of carbon covalent bonds decreases.

The lack of qualified geotechnical data for the foundation design process is a present and growing concern among the consultancy practitioners. The clients have been increasingly reluctant to commit to extensive but necessary site investigative program that has no immediate economic benefits or perceived to impede work progress. Consequently, the risk of foundation failure and over-design are a potential reality. Even so, the construction pace is unrelenting. The research attempted to address such a quandary via a project case study with not too dissimilar limitation with respect to the availability of geotechnical data. Selecting the best available data for the type of foundation selected, further analyses were carried out in order to obtain collaborative strength information with the appropriate application of the factor of safety. Next, selection of the governing value from among the derived strength parameter had been based on the currency and accuracy of the testing process. Finally, provisional qualifiers had been attached to the design proposals in case alternate scenarios were encountered during the implementation stage. In the context of the case study, a reasonable driven pile capacity of 15.55 tonnes as determined from the PDA test has been recommended contingent upon the prescribed project scale and ground conditions.

Pollution dilemma due to plastic bottle waste disposal and buildup is a growing and persistent problem in Malaysia. Clearly, innovate use of such wastes through recycling application in engineering must be found. This research was aimed to utilize waste plastic fiber in problematic road construction project that can be both economical and environmentally friendly. Additionally, it has the potency to increase the mechanical strength of commercial sand through the CBR parameter of the road pavement sub-grades. The sand usually possesses low CBR value which on its own may not be entirely suitable for the road construction works unless additive or stabilizer was added. In this study, the specimen used as additive to the sand involved 5 mm wide × 10 mm wide plastic fiber which was obtained from shredded waste plastic bottles. There were several percentage of waste plastic fibers that had considered in the research apart from the control specimen namely at 0 %, 0.1% and 0.5% in conjunction with 5 % cement and water at optimum moisture content level. Several laboratory tests had been prescribed namely characterization tests, compressibility test and CBR test. The result shows that as the percentage of waste plastic fiber increased, the CBR value also increased indicating positive relationship between the two variables.

In this study, polymer blend was prepared in the ratio of Polypropylene (PP) to Polylactic acid (PLA) of 70:30 by weight. Bamboo charcoal powder (BC), at different loading was added to identify its potential use as filler for the PP/PLA blend. The polymer blend and composites were prepared by using a twin screw extruder. The effects of BC content on the mechanical and thermal properties of the PP/PLA blend were investigated. The results of tensile strength and Izod impact strength show a significant decreased with the addition of BC content. The Young modulus of composites was significantly increased (80%) with the addition of 20 wt.% BC content. The SEM results of composites with 20 wt.% BC filler show a brittle fracture surface. TGA results revealed that, blending PP with PLA cause an increase in thermal stability of PLA. However, the incorporation of 20 wt.% BC has shifted the temperature of initial weight loss of PP/PLA blend towards lower temperature. DSC measurement indicates that the melting temperature (T_m) values of the PP/PLA blend decrease with the addition of 20 wt% BC content, from 169 to 164 °C.

This paper presents the numerical study on the usage of Al₂O₃ nanofluid-filled heat pipes in controlling the temperature of lithium-ion batteries, specifically for the application in powering the electric vehicle (EV). The heat pipes thermal management system (HPTMS) was modelled as a solid continuum body with high equivalent thermal conductivity. Thermal resistance network model was used to determine the equivalent thermal conductivity. The effect of heat inputs and the nanoparticle volume concentration on the performance of the HPTMS were studied. The simulation results were validated against previous experimental works and showed good agreement with each other. Results also indicate that by using 1.5%vol Al₂O₃ as the working fluid in the heat pipes, the battery surface temperature and the total thermal resistance can be reduced by as much as 4.44°C (7.28%) and 15%, respectively.

Voltage flicker is one of the vital disruptions in electrical distribution power systems. An electric arc furnace is considering as one of the major causes of voltage flicker due to it an unbalanced, nonlinear and time-varying behaviours. Distribution Synchronous static compensator (D-STATCOM) has been shown to be a competent and dynamic device to compensate voltage flicker in power system. This paper presents a comparison between Phase-Loop Locked (PLL) Controller and Synchronous References Frame (SRF) Controller technique for 6-pulse D-STATCOM to compensate voltage flicker due to electric arc furnace load. To observe the effectiveness of the proposed technique, testing has been conducted on IEEE 13 distribution bus test system. The simulation results show the effectiveness of 6-pulse D-STATCOM using PLL Controller compare to the SRF Controller techniques to alleviate the fast-varying voltage flicker.

Polymer flood is known as the most important enhanced oil recovery technology due to its various advantageous and relatively cheaper price. However, it comes with associated problems of polymer adsorption that leads to injectivity loss. This work aims in studying various parameters that may affect the ATBS/ Acrylamide copolymer adsorption in a porous medium to optimize the polymer scheme. Synthetic D brine with D sand sample was mixed and tested in static and dynamic condition. These tests were conducted at room temperature and 90°C whereby the core flooding experiments were conducted with varied flowrate through Berea Sand Core sample. Results show that a higher brine salinity and a longer aging time leads to higher adsorption rate whereas adsorption static test conducted at replicated reservoir condition of 90°C resulted in lower adsorption capacity than at room temperature. Also, static adsorption was found to be higher than the dynamic adsorption due to the changes in the specific surface area and the extent of mechanical retention present in the dynamic core flood experiment. In conclusion, the type of polymer used in polymer flooding must be carefully chosen to serve the need for a specific reservoir condition so that the adsorption phenomenon is minimized.

The utilisation of discrete fibre in the soil reinforcement technique to overcome the problems of soft compressible soil are investigated in this paper. Two different type of fibre is used herein, i.e. polypropylene and plastic fibre. Shear strength of soils is highly affected by moisture conditions. In practice, a laboratory investigation conducted to determine the shear strength of soil is prepared at optimum moisture content. However, at field conditions, the actual water content may vary. The effect of moisture variation with respect to optimum moisture content is investigated in this study. Unconfined Compressive Strength Test was carried out to study the effect of fibre type, fibre content and soil moisture condition. The test results indicated that the reinforced soil using polypropylene fibre provides higher strength increment compared to plastic fibre. The highest strength was achieved at 0.15% additional of polypropylene fibre in the dry moisture condition.

Bamboo is known as one of the quick growing plant due to its unique rhizome-dependent system. Its fiber owns the lowest density in comparison with the other natural fibers. The bamboo fibers can be used as innovative fibers in concrete. It can increase the strength of the concrete and improve the ductility of concrete. This study investigates the influence of different percentages of bamboo fiber in concrete through the compressive strength results. There are three different percentages of bamboo fibers to be incorporated in the concrete. A demonstration of utilising the bamboo as the steel reinforcement replacement is also presented in this study. From this study, an optimum percentage of 0.5% of incorporation of bamboo fiber as an addition in the concrete mix provides the highest compressive strength. From the three point load test, the concrete beam specimen cast with the addition of bamboo fibers yielded the prominent outcome. The findings of this study proved that the bamboos have a good potential for its application in the concrete application.

This research aimed to extract copper ions from aqueous solutions with oleic acid as a green solvent. The effects of pH equilibrium, temperature, and sodium sulphate (Na₂SO₄) concentration were investigated and the optimum conditions for maximum extraction of copper ions were determined. The findings revealed that the extraction of copper ions increased with equilibrium pH and temperature before it reached a plateau, while it increased and achieved a peak before it decreased with sodium salt concentration. The highest extraction of copper ions was achieved at 94% under the following optimum conditions: equilibrium pH of 4, temperature 55°C and 400 mM of Na₂SO₄. Therefore, it can be concluded that oleic acid is a potential green solvent for extracting copper ions from aqueous solutions.

Red soil is a type of soil that rich in iron and abundantly can be found in Malaysia. However, the application of red soil is limited to agriculture, building blocks, road building and waste water treatment. Chemical looping combustion (CLC) is one of the carbon-capturing technology, in which oxygen from oxygen carrier reacts with fuel inside fuel reactor to produce pure CO₂ and H₂O. In this research, effect of MgO as supported material was investigated in order to produce desired oxygen carrier from red soil. The composition of 95:05, 90:10, 80:20 and 70:30 of red soil and MgO, respectively, was varied in this research. The phase analysis, morphology, surface area and pore volume size were investigated using X-ray, Field Emission Scanning Electron Microscopy (FESEM) and Brunauer-Emmett-Teller (BET) analysis, respectively. From this study, composition of 90:10 of red soil and MgO, respectively, was found to have high surface area which is 56.95 m²/g with pore volume size of 0.145 cm³/g, and has low crystallite size which favourable as oxygen carrier.

Microencapsulation is a technique in which small particles are enclosed by a coating wall. Microencapsulation has been widely used in applications such as the controllable release of essential oils and improvement of the stability of the core substances and many other fields. Volatiles liquids and solids are easily damaged during long term use, due to their external environment. This leads to degradation and loss of function. In preventing this drawback, encapsulation of essential oils by embedding them into polymer wall has been introduced. In this study, citronella oil (CO) encapsulated by gelatin-chitosan was prepared by complex coacervation technique. Report on release study of encapsulated CO and its applications in floor cleaning solution is very limited. Hence, release rate and release mechanism of the microcapsules in simulated floor cleaning solution (Tween 80 solution) were investigated. Morphology of the microcapsules was determined through optical microscope. The release of CO was observed through the formation of rupture on the spherical microcapsule. The release rate of encapsulated CO increases with the increase of temperature from 25°C to 75°C. The release mechanism of the CO, based on Fick's law was classified as following the Korsmeyer-Peppas controlled release model of super case II, whereby the release is due to wall erosion.

Fenton process can be regarded as powerful and effective method in decolorization and mineralization of dye pollutants. However, this method is restricted with the generation of iron waste sludge which require secondary treatment. This limitation can be overcome by utilizing heterogeneous Fenton process where iron ions are immobilized onto the catalyst support. In the present study, the heterogeneous Fenton-like oxidation using Fe-natural zeolite (Fe-NZ) was investigated in decolorization of azo dye Acid Red 1 (AR1). The effects of iron ions loading, catalyst dose and initial pH on the decolorization of AR1 were evaluated. The maximum decolorization efficiency of 99.60% was achieved at 0.80 wt% of iron ions loading, 5.0 g/L of catalyst dose, and at 2.5 initial pH. The Fe-NZ showed high catalytic performance for decolorization of AR1 and could be regarded as a suitable low-cost catalyst in heterogeneous Fenton-like reaction.

Food waste (FW) and empty fruit bunches (EFB) possess a great potential to be used for anaerobic digestion process, as these two biomasses are rich in biodegradable organic matter, in which its contents play an important role in determining the efficiency of the digestion process. In this study, the elemental compositions, nutrients content, and lignocellulosic content of Malaysian FW and EFB were determined by running several procedures and were compared to past literatures which also used similar feedstock for anaerobic digestion; to determine whether the biomasses used in this study could lead to better performance of anaerobic digestion. Elemental analysis of the FW showed that the C/N ratio ranged from 4.45 to 15.45, within the optimum range as defined by past studies. For EFB, the C/N ratio was similar to FW, making EFB suitable to be mixed with FW for optimum anaerobic digestion conditions. Nutrients analysis of the FW showed that FW Types A and D, rice waste and food waste mixture respectively, possessed the most balanced carbohydrates, proteins and lipids nutrients for optimum digestion. Lignocellulosic analysis of the EFB also proved that its contents were favourable to be used in anaerobic digestion; high cellulose content, low lignin content.

Salmonella typhimurium is a Gram negative pathogen that commonly causes severe gastroenteritis. It is resistant to a wide range of antibiotics and is able to form biofilm on both biotic and abiotic surfaces. To date, essential and non-homologous proteins in S. typhimurium biofilm remain not well investigated. Therefore, the present work was performed to analyze essential and non-homologous proteins in S. typhimurium biofilm using a combination of one-dimensional SDS-PAGE, HPLC - ESI - QTOF and bioinformatics. Results demonstrated that seven major protein bands (78.1 kDa, 51.2 kDa, 41.5 kDa, 37.3 kDa, 35.1 kDa, 27.6 kDa, and 25.4 kDa) were present in whole-cell protein extract of S. typhimurium biofilm. A total of 75 proteins were successfully identified from both 25.4 kDa and 51.2 kDa protein bands. Approximately 54.67% of QTOF-identified whole-cell proteins were found to be essential to the survival of S. typhimurium biofilm and were non-homologous to human proteome. Majority of essential and non-homologous S. typhimurium biofilm proteins were associated with transport and protein synthesis. The findings from the present work may be useful for development of novel antibiofilm agent.

Bio-phenol formaldehyde adhesives formulated from sustainable biomass sources is an excellent alternative to phenolic petroleum-based adhesives with lower pollution level. This study aimed to formulate bio-adhesive from two types of biomass namely palm kernel shell (PKS) and Leucaena sp. Wood. The intention was to find the best process condition which results in maximum content of bio-phenol in the product. The bio-based phenolic resins (bio-oils) were produced from gasification process and their physical and chemical properties were determined. Both produced bio-oils were involved in formulation of bio-based phenol formaldehyde adhesives (resinification) at different operating conditions (temperature, time and catalyst loading). The chemical functional groups and individual compounds of the phenol resins and bio-adhesive samples were identified by GC-MS. The results indicated that temperature has persistent increasing effect on phenol percent of the bio-oil from Leucaena sp. wood however for the bio-oil from PKS the increase of phenol was until the temperature of 85 °C. Reaction time and catalyst loading were observed to have similar effects on resinification of both bio-oil samples. The bio-adhesive produced under best operating condition has the highest amount of bio-phenol and therefore is considered an environmental friendly adhesive with lower cost and pollution than the petroleum-based types.

Lost circulation is one of the most severe issues in drilling operation which can cause fracture formation or be induced during drilling activities. These scenarios make it imperative to design the drilling fluid in a minimal invasion of the fluid that occur in the formation along with assist in strengthening the wellbore condition. To solve this problem, Lost Circulation Materials (LCM) are required which is expected to bridge and seal the fractures. As the contemporary worldwide development towards environment friendly, technical ability and cost-effectiveness, hence the viability of Egg Shells as LCM are being investigated since the daily disposal waste is rich in Calcium Carbonate (CaCO3) compound. In addition, the effect of egg shell particle size distribution on the drilling fluid performance was also study. The performance of egg shells was compared with the industry standard-sized CaCO3 in term of its rheology properties, fluid loss, fluid invasion, and lubrication ability. The rheology properties result shows a stable reading while for High Pressure High Temperature (HPHT) filter press test, the drilling fluids performance showed the same mud cake thickness of 1/32 but slightly different in fluid loss. The drilling fluids also has a minimal invasion on Sand Bed Test (SBT) with lubrications coefficient of 0.0753. From this study, it is found that egg shells can function effectively as LCM additives, the same as the standard CaCO3 used in the industry.

The effect of HAP and Al₂O₃ composition with constant of ceramic content of 15 wt. % on mechanical properties, microstructure, and corrosion behavior of degradable Mg-Zn/HAP/Al₂O₃ hybrid composite developed by powder metallurgy method were investigated. The microstructure was analyzed using an optical microscope and scanning electronic microscope while mechanical properties were evaluated for density and compression strength. Meanwhile, corrosion behavior in Hank Balanced salt solution (HBSS) was studied for 4 h. The addition of HAP and Al₂O₃ particles has improved the mechanical properties and corrosion properties of Mg-Zn alloy. The results show that 15 wt. % Al₂O₃ (without HAP) shows the higher density, hardness, and compression. However, the composite consisted of 10 wt. % HAP with 5 wt. % Al₂O₃ shows the lower corrosion rate.

In this present study, Density Functional Theory (DFT) calculations were conducted to study the structural and electronic properties of (1,1), (2,2), (3,3), and (4,4) Boron Nitride (BN) systems. Geometry optimization calculations were carried out to find the stability of BN cluster models. The obtained structural geometries are consistent with that obtained in the previous reported results [1]. The total energies increase when the cluster sizes of BNs increase. For each cluster size of BN, the four total energy values obtained from B3LYP level of theory with employing the basis sets of 6-31++G, 6-31++G**, 6-311++G, and 6-311++G** are close to each. Moreover, our computations revealed that the gap energy values of HOMO-LUMOs in the BN cluster structures have been decreased by following its structure and dimensionality. The calculated HOMO-LUMO gaps are 5.99 eV - 7.68 eV in this study. For the diagrams of molecular electrostatic potential (MEP) surfaces, the regions around the N atoms at the center hold the highest electronegative potential, which can attract more electrons in the BN systems. With a Mulliken population analysis (MPA) scheme, all the boron atoms possess the positive charges, whereas the negative charges were found on the nitrogen atom in the BN systems.

TiO₂-CuInS₂ is one of the promising materials for 3D nanocomposite solar cells. To utilize for 3D nanocomposite solar cells, TiO₂-CuInS₂ should well deposited onto transparent conducting oxide such as indium doped tin oxide (ITO). High pressure coating with liquid carbondioxide (l-CO₂) was successfully deposited TiO₂-metals chalcogenide onto ITO substrate. Further heat treatment (oxidation and sulfurization) lead the formation of CuInS₂ from metals chalcogenide deposited on the mesoporous TiO₂. The formation of CuInS₂ on the was confirmed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and Raman spectroscopy. The atomic ratios of deposited CuInS₂ were nearly stoichiometric after sulfurization. The crystal growths of CuInS₂ were controlled by adjusting the number of coating cycles.

Manufacturing industries and servicing providers have successfully implemented lean tools during managing and controlling the activities. This study was carried out at pickle manufacturer one of Small Medium- sized Enterprise (SME) in Malaysia to reduce non-value added activities using some tools from time and motion study and Delmia Quest software. Solutions were suggested to reduce non-value added activities which yielded improvement of 24% and 36% in labor utilization and 25% in daily output.

Food waste samples from various categories were examined for their energy content. In this work, the objective was to characterize the energy contents in food waste to assess their potential for renewable energy resources. The food waste samples that were analysed included tofu, carrot, corn, chicken, biscuit, rice and beef. The food wastes were characterized by proximate analysis using Thermogravimetric Analyser (TGA) and by ultimate analysis using Elemental Analyser (CHNS-O). The energy content in food waste was then evaluated using various higher heating value (HHV) correlations that were researched and established by many researchers. The results from both analyses demonstrated that the energy content from the higher heating value (HHV) calculated by using different equations indicated the food waste usage as an energy source. The highest HHV was found in the beef. Among the samples prepared, it can be observed that the most efficient 'waste-to-energy' sample is the protein-based food because this food has the highest amount of volatile matter with the lowest amount of ash content and fixed carbon content. Plus, protein food gives the highest percentages of carbon and hydrogen elements in order to help the combustion process going perfectly in order to convert it into an energy source.

The use of membranes is widely common in bioprocess industry to separate constituents of a liquid, especially during cell clarification process. Many has opted for normal flow filtration mode for this process due to the ease of handling of this technique as compared to tangential flow filtration. Meanwhile, antifoams are chemicals used in upstream process to eliminate the formation of foam throughout the course. It is normally used in conjunction with a nutrient rich broth that is used as a media to cultivate the cells. Some has claimed that antifoam may lead to premature membrane fouling, but some reported that the presence of antifoam may assist and improve the flux rate of the filtration process. This study investigates the effects of organic antifoam presence in a cell-free media on the performance of the filtration process, specifically normal flow filtration process. It was discovered that the presence of organic antifoam may be significant at 1.0% concentration of antifoam loaded in the sample which gives filtration capacity of 250L/m2 while filtration capacity was reported to be at 330L/m2 for samples containing 0.2% and 0.6% antifoam concentration. The flux rate profile has lower percentage reduction that ranges from 18% to 33% which resulted to final flux rate of approximately 700 – 800LMH for initial flux rate of 1000LMH and 27% to 46% reduction that lead to final flux rate of approximately 1000 – 1500 LMH for initial flux rate of 2000LMH.

The selection of a good catalyst support is crucial in contributing towards the enhancement catalytic activity of a catalyst. Therefore, in this study, the influence of montmorillonite KSF (MKSF) clay loading in relation with catalytic performance of the resultant composite catalyst has been investigated. The MKSF clay loading were varied at x = 20, 40, 60 and 80 wt%, respectively. Interestingly, Fe_3-0.3Mn_0.3O₄-MKSF(40wt%) has shown greater catalytic performance up to 98% of acid orange II (AOII) dye removal in comparison to the Fe_3-0.3Mn_0.3O₄ and Fe₃O₄ catalysts. The AOII degradation kinetic using Fe_3-0.3Mn_0.3O₄-MKSF(40wt%) was fitted well with first-order reaction kinetic and the reaction rate increased in the order of Fe₃O₄>Fe_3-0.3Mn_0.3O₄>Fe_3-0.3Mn_0.3O₄-MKSF(40wt%). It also demonstrated in the work that Fe_3-0.3Mn_0.3O₄-MKSF(40wt%) catalyst can be reused several times without affecting its efficiency. Thus, it can be suggested that MKSF clay as catalyst support played a significant role in enhancing the overall catalytic performance of Fe_3-0.3Mn_0.3O₄ catalyst during the heterogeneous Fenton-line reaction as well as the degradation kinetics of the AOII solutions.

Renewable energy from biodiesel or fatty acid methyl ester (FAME) has become important in recent decades as one of the promising alternative for petroleum-derived fuel. In this study, chromium based mixed oxide catalysts which are Cr/Ca oxide and Cr/Zn oxide were synthesized via precipitation method and used in the transesterification of cooking palm oil to produce FAME. The reactions were conducted in a batch reactor at temperature of 60 °C, methanol:oil molar ratio of 6:1 and catalyst loading of 1wt%. The characterization through N₂ adsorption-desorption showed BET-surface area, pore volume and pore size of Cr/Ca oxide are 3.6915 m²/g, 0.00684 cm³/g and 93.919Å, respectively while for Cr/Zn oxide are 3.9897 m²/g, 0.00630 cm³/g and 80.113Å, respectively. Both catalysts showed similar type isotherm which are type IV and hysterisis loop H3. The catalyst Cr/Ca oxide is found to be more active in the transesterication whereby FAME content of 27.8% was achieved compared to 7.4% by utilizing Cr/Zn oxide. The results showed that Cr/Ca oxide catalyst and Cr/Zn oxide have potential as heterogeneous catalyst to produce FAME from palm oil.

Hibiscus sabdariffa or Roselle seed is an agricultural product which possesses a large amount of nutritional content that could be useful in wide application. Drying process can be helpful to conserve the seeds for long storage periods. For this reason, the drying behavior of Roselle seeds was investigated using laboratory oven at various drying temperatures (35, 45, 55, 60 and 65°C). It is found that the drying process of the Roselle seeds consists of constant rate and mostly falling rate period at where the moisture content of Roselle seed decreases as time goes. Adequately suitable drying temperature is found to be 65°C with the drying time of 240 minutes. The drying behavior of Roselle seeds is further understood through the drying kinetics of the Roselle seeds. Five empirical mathematical models were selected to describe and compare the drying characteristics of Roselle seeds at respective drying temperatures. Drying rate constants, coefficients and statistical parameters were determined by non-linear regression analysis, and therefore, the diffusion approach model was selected as the best model with R value obtained is 0.999 while MBE, RMSE and χ2 values of 2.37E-04, 0.01335 and 0.007794 respectively.

Increase in population growth coupled with industrialization, urbanization and requirements for implementation of stricter effluent discharge standards, sludge from wastewater treatment plants (WWTP) is expected to be produced in a continually increasing amount globally. The management of the huge volume of sludge generation becomes an integral component of environmental sustainability. Therefore, the need for environmentally friendly approach to sludge management strategy couldn't be overemphasized. This paper proposes a rational and more sustainable approach directed towards devising means to solve the problem of the huge amount of WWTPs sludge by converting it to granular activated carbon (GAC) for utilization in water pollution control via incorporating Life Cycle Assessment (LCA). The paper reviews the various approaches and techniques for drying, pyrolysis and activation techniques and the best operating conditions for sludge based activated carbon (SBAC) for optimal pollution control. Based on that, a holistic decision making tool was recommended which incorporates major production, treatment and disposal options for each stage using Life Cycle Assessment (LCA) approach (from-cradle-to-grave), from which wide range of alternative scenarios will be generated vis-à-vis water pollution control efficacy in relation to environmental, cost as well as energy implications.

This work reports the potential use of polyaspartate (PASP) synthesized from L-aspartic acid via a newly modified thermal procedure as a soil washing chelating agent for Zn ions removal from contaminated-soil. Response surface methodology (RSM) via faced central composite design was employed for evaluating and optimizing the influence of operational parameters. RSM response models developed describe well the Zn removal efficiency with high R2 (> 0.994-0.998; p-values < 0.001) and in-significant lack of fit. Zn washing efficiency was found to increase with increase in Zn initial concentration and decrease in PASP/soil ratio. The relative contribution of the operating conditions on Zn removal follows the order; PASP/soil ratio, initial heavy metal concentration, PASP concentration, initial pH and extraction time. Optimal conditions occurred at 500 mg/kg Zn concentration, 36 mM PASP concentration, 10 polymer-soil ratio, pH 4 and 6 hours retention time when Zn ions removal was 39% with most efficient PASP utilization. Although, 100% removal of Zn was achieved at low Zn concentration (100 mg/kg), yet, more amount of the PASP was needed. These results demonstrated the feasibility of effective utilization of PASP for decontamination of Zn ions polluted soils.

This work examined sonocatalytic degradation of caffeine in the presence of CeO₂ prepared by hydrothermal method. Several characterization techniques were used to study the CeO₂ including TEM, XRD and BET method. Effects of various parameters such as pH, initial concentration of caffeine and dosage of CeO₂ were investigated. This study also examined the reusability of CeO₂. Results showed that the CeO₂ had mixed shapes of crystallites consisting of rods and cubes with the specific surface area (Sbet) and pore volume of 126.63 m²/g and 0.4898 cm³/g, respectively. About 95.5% of caffeine degradation was achieved under the best parameter conditions i.e. at pH of 7.5, 5.0 mg/L of initial concentration of caffeine and 1.0 g/L of CeO₂ dosage within 150 min. It was also revealed that the operating parameters played major roles in caffeine degradation efficiency. In addition, the CeO₂ were quite stable since the efficiency of caffeine degradation achieved in the third cycle was 81.4%.

Recently, research on the development of biodegradable material were performed. However, biodegradable materials have a crucial weakness in terms of mechanical properties, but it can be improved by adding reinforcement material as filler. In this study, Pineapple Leaf Fibre(PALF) was chosen as filler due to its many advantages, such as low cost, variety and redundant sources and bio-degradable. The objective of this research is to investigate the effect of PALF fibre loading to the corn starch composites in terms of physical, mechanical and morphological properties. The samples were prepared at different fibre loadings: 5 wt%, to70 wt %, and were fabricated by using the hot press machine. The result showed that physical properties, such as density, water absorption and moisture content, were affected by different fibre loadings. Mechanical properties of the composite samples showed that PALF with 30 wt% gave the optimum tensile strength and modulus. Morphological analysis, composite samples of 30 wt% PALF fibre loading had fewer gaps between matrix and fibre. It can be concluded that 30 wt% of fibre loading is the optimum fibre loading for 3cm length PALF as compared to other composition ratios.

Soil nailing is a popular application in soil slope stabilization. Failure of soil nailing could be mainly due to the issue of installation such as inaccuracy of actual length of the soil nail and integrity of cement grout annulus during grouting. This study focuses on using non-destructive technique of time domain reflectrometry (TDR) to monitor the quality of soil nail. TDR is originally used to detect changes in geometry and electromagnetic properties (dielectric or magnetic) happening along its transmission cable and detect the damage or leakage from the cable. The objective of this study is to use high resolution TDR and coaxial cable to detect changes of grout condition in soil nail. Results confirm the suitability of high resolution TDR and coaxial cable to detect void length which relates to grout condition in soil nail. The findings conclude that high resolution TDR model T631 and coaxial cable type RG-6 are capable to detect even small size void and is suitable to be applied for soil nail monitoring.