Table of contents

Preface

It is our great pleasure to welcome you to The 7th International Conference on Key Engineering Materials which will take place in Penang, Malaysia on March 11-13, 2017. ICKEM2017 is dedicated to issues related to Key Engineering Materials.

The major goal and feature of the conference is to bring academic scientists, engineers, industry researchers together to exchange and share their experiences and research results, and discuss the practical challenges encountered and the solutions adopted. Professors from Britain, France and Japan are invited to deliver keynote speeches regarding latest information in their respective expertise areas. It will be a golden opportunity for the students, researchers and engineers to interact with the experts and specialists to get their advice or consultation on technical matters, sales and marketing strategies.

These proceedings present a selection from papers submitted to the conference from universities, research institutes and industries. All of the papers were subjected to peer-review by conference committee members and international reviewers. The papers selected depended on their quality and their relevancy to the conference. The volume tends to present to the readers the recent advances in the field of key engineering materials and various related areas, such as performance analysis and testing of composites, synthesis and preparation of metal materials, thin film and energy materials, application of building materials, biochemical materials, etc.

We would like to thank all the authors who have contributed to this volume and also to the organizing committee, reviewers, speakers, chairpersons, sponsors and all the conference participants for their support to ICKEM 2017.

Prof. Alexander M. Korsunsky MA DPhil CPhys Minst

Trinity College, Oxford, UK

April 20, 2017

All papers published in this volume of IOP Conference Series: Materials Science and Engineering 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.

Stinging Nettle (Urtica dioica L., latin) is a wild plant that grows in Indonesia, Asia, and Europe. Nettle in Bali, Indonesia is called as Lateng, Jelatang. Nettle plant has a very strong fiber and high fixed carbon. Nettle plants are covered with fine hairs, especially in the leaves and stems. When it is touched, it will release chemicals, sting and trigger inflammation that causes redness, itching, bumps and irritation to the skin. Nettle plants grow in the wild, regarded as a weed in the agricultural industry, easy to grow and snatch food from the parent plant. The main objective of this paper is to review of the potential nettle fibers and then explain about the potential of local nettle plant in Indonesia. Nettle is a plant group at the end of bast. Its plant fibers taken from the bark, as reinforcement in composite materials. Nettle fibers have three main advantages such as strong, lightweight and low environmental impact.

Untapped areca catechu l. husk fibers optimally can cause pollution to the environment. Therefore it is necessary to learn the characteristics of local balinese areca catechu l. husk fibers, such as physical, chemical, morphological, and mechanical. AHF testing the tensile strength with a single pull fiber test in accordance with ASTM D 3379 in the amount of 146-152 MPa. While the observation of the physical properties, of local balinese areca catechu l. husk fibers have a diameter and length variations of each 250-540 μm and 9.24 to 55.20 mm, with an aspect ratio of between 31.43 to 102.22, density ranges between 0:48 - 0.74 kg / cm³, absorption lower water (90-150%) when compared to AHF grows in other areas. From this study it appears that local Bali AHF can be used as reinforcement in composite replacement for synthetic fibers.

The effect of thermoset resin type and geothermal silica loading on the mechanical properties and water sorption of geothermal silica/thermoset composites are determined. Thermoset resin type has significant effect on the flexural strength, hardness, water uptake and weight loss of the composites. Composites based from isophthalic polyester resin has higher flexural properties and hardness and lower water uptake and weight loss over other types. Geothermal silica loading has significant effect on the hardness and water uptake of composites. The highest hardness and water uptake were observed at 5%w/w geothermal silica loading.

Polyethylene (PE) contributes largely to plastic wastes that are disposed in aquatic environment as a consequence of its widespread use. In this study, yellow oxo-biodegradable low-density PE films were immersed in deionized water at 50°C for 49 days. Indicators of water quality: pH, oxidation-reduction potential, turbidity, and total dissolved solids (TDS), were monitored at regular intervals. It was observed that pH initially rises and then slowly decreases with time, oxidation-reduction potential decreases then slowly increases with time, turbidity rises above the control at varied rates, and TDS increases abruptly and rises at a hindered rate. Moreover, the films potentially leach out lead chromate. The results imply that degrading oxo-biodegradable LDPE films results to significant reduction of water quality.

This study investigated the effect of stearic acid (SA), glycerol monostearate (GMS) and 3-trimethoxysilylpropyl methacrylate (TSPM) at varied loadings on the hardness and flexural properties of modified geothermal scale powder (GSP)/stereolithography (SLA) polymer composite. TSPM-modified GSP/SLA composite has the highest value of hardness due to increased filler dispersion and crystallinity. Hardness of GSP/SLA composite increases with loading of surface-modifying agent due to increase filler dispersion. Pronounced effect of surface modification to flexural modulus is observed. While low loading of SA and GMS leads to reduction of flexural modulus, increasing loading enhances the said property. Further increase of SA deteriorates the property. TSPM-modified GSP enhances the modulus due to increased crystalline phase of the system owing to TSPM copolymerization. Likewise, addition of SA and GMS increases flexural strength due to efficient reduction of filler agglomerates. However, unreacted TSPM produces weak interfaces and poor adhesion between GSP and SLA matrix.

Adsorption is a separation process that has higher energy efficiency than others. Analyzing the nature of the adsorbate and the selection of suitable adsorbent are key success in adsorption. The performance of the adsorbent can be modified either physically or chemically to obtain the efficiency and effectiveness of the adsorption, this can be facilitated by using a composite adsorbent. In this study, we have conducted the preparation process of a polyvinyl alcohol (PVA)/zeolite/carbon composites. The resulting adsorbent composites are dedicated for ethanol – water dehydration proposes. The composites were prepared using cross-linked polymerization method followed by supercritical fluid extraction (SFE) to obtain the porous structured upon drying process. The characterization of the functional groups and morphology were performed by using Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscopy (SEM), respectively. The FTIR analysis showed that composite prepared by SFE method formed hydrogen bonding confirmed by the appearance of peaks at 2950 – 3000 cm^-1 compared to composite without SFE method, whereas, the results of SEM study showed the formation of three layered structures. On basis of the obtained results, it can be shown that PVA/zeolite/carbon has high potential to be develop further as an adsorbent composite.

Water-triggered release of antimicrobial solutions is advantageous in inhibiting the growth of bacteria and fungi in moist and wet environments. In this study, we fabricated a composite, by mixing polyvinyl acetate adhesive with copper sulfate solution, which exhibits antimicrobial activities against bacteria. Polyvinyl acetate adhesive serves as the binder and water soluble substance while copper sulfate serves as the antimicrobial agent. The composite was coated in an acetate film and air-dried. To monitor the rate of release of copper ions, the composite was submerged in water and the conductivity was measured. The conductivity saturation time was determined. The composite showed antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive).

Aircraft elements, especially elements of exterior fuselage, are subjected to damage caused by lightning strikes. Due to the fact that these elements are manufactured from polymeric composites in modern aircraft, and thus, they cannot conduct electrical charges, the lightning strikes cause burnouts in composite structures. Therefore, the effective lightning strike protection for such structures is highly desired. The solution presented in this paper is based on application of organic conductive fillers in the form of intrinsically conducting polymers and carbon fabric in order to ensure electrical conductivity of whole composite and simultaneously retain superior mechanical properties. The presented studies cover synthesis and manufacturing of the electrically conductive composite as well as its characterization with respect to mechanical and electrical properties. The performed studies indicate that the proposed material can be potentially considered as a constructional material for aircraft industry, which characterizes by good operational properties and low cost of manufacturing with respect to current lightning strike protection materials solutions.

Brake lining pad as one of the active safety components in motor vehicles has been studied thoroughly. Asbestos is the main material forming the brake in addition to other alloy materials that have a negative impact on health and the environment. This paper explain the behavior of hybrid composites phenolic resin with basalt/alumina/clamshell powder reinforced on brake lining pad. This materials has been manufactured use compaction and sintering process through any steps, that an emphasis of 2,000 kg for 30 minutes at a constant temperature of 150° C. The research aims to investigate hardness characteristic of hybrid composite that test using the vickers according to standard ASTM E-384. The reinforced materials and phenolic resin composition is 60%: 40%. The results show for the average hardness VHN to 24.18, 25.11, 26.34, 27.21 and 28.83. The average hardness hybrid composite shows the hardness harder than asbestos materials.

An injectable calcium phosphate (CaP) bone cement has been widely used for musculoskeletal and bone disorder due to its biocompatible and osteoconductive properties. In this study, CaP was successfully synthesized from crab shells by a wet chemical route. Poly(lactic-co-glycolic acid) (PLGA) microspheres which have been produced through a double emulsion technique were incorporated into the CaP mixture for the purpose of bone cement solidification. The ratio of both compounds, CaP and PLGA, were set at 8:2. The CaP and PLGA/CaP bone cement were analyzed by ATR-FTIR, FESEM-EDX and contact angle analyses. The bone cement was composed of CaP and PLGA where the micro-powders of CaP were agglomerated on the PLGA microspheres. Addition of the PLGA has increased the hydrophilicity of the bone cement which will be beneficial for materials degradation and bone integration.

This paper investigated the possibility of using crumb rubber as partial replacement to fine aggregate in roller compacted concrete for pavement applications where fine aggregate was replaced with crumb rubber at 0%, 10%, 20% and 30% to produce roller compacted rubbercrete (RCR). In order to achieve a combined aggregate gradation similar to the one recommended by ACI 211.3R and US Army Corps of Engineers method, fly ash was used as mineral filler. Several trials were done to achieve the combined grading, and finally a combination of 55% fine aggregate, 40% coarse aggregate and 5% fly ash as mineral filler was used. Silica fume was then used as mineral filler instead of fly ash and the fresh density and compressive strength were compared. A target flexural strength of 4.5 MPa and the mix design was developed using the geotechnical concept according to ACI 211.3R/CRD-C161-92. The Results showed that fresh density and compressive strength decreases with increase in partial replacement of fine aggregate with crumb rubber. RCR containing silica fume showed lower fresh density and higher compressive strengths than that with fly ash. However, all the mixes achieved a strength higher than the design target strength at 28 days except for 30% crumb rubber containing fly ash mineral filler, while 10% crumb rubber achieved target strength even at 3 and 7 days for silica fume and fly ash.

In this research, composite nanosilica/polyethylene modified binder samples were prepared at varying concentration of nanosilica. The modified binder samples are prepared by adding 1%, 2% and 3% nanosilica by weight of bitumen in to 6% linear low density polyethylene (LLDPE) polymer modified binder. Effects of nanosilica on physical and rheological properties of composites were investigated through penetration, softening point, temperature susceptibility, dynamic mechanical analysis and rutting resistance evaluations. Results shows that, nanosilica affects the rheological properties of LLDPE modified binder due to decrease in penetration and increase in softening point observed with increase in nanosilica content, this enhances composite binders hardness and resistance to temperature. Temperature susceptibility shows that, composite modified binders are less susceptible to temperature compared to LLDPE modified binder. DSR rheological analysis shows that, nanosilica enhances the composite modified binders properties at intermediate to high temperatures. Also rutting parameter evaluation indicates that composite modified binders have high resistance to rutting deformations due to increase in elastic behavior and stiffness of the composites.

Evaluation of the effects of nano-silica amount and superplasticizer (SP) dosage on the compressive strength, porosity and slump flow on high-volume fly ash self-consolidating mortar was investigated. Multiobjective optimisation technique using Design-Expert software was applied to obtain solution based on desirability function that simultaneously optimises the variables and the responses. A desirability function of 0.811 gives the optimised solution. The experimental and predicted results showed minimal errors in all the measured responses.

The increase in greenhouse gas emissions has been a factor for the increase in global temperature. Geopolymer cement has been intensively studied to replace conventional ordinary Portland cement, however the focus is limited to civil purposes under atmospheric conditions. This research focuses on the formulation of geopolymer cement to be used in oil well cementing application by taking account the effect of sodium hydroxide (NaoH) molarity, ratio of alkali binder and fly ash, amount of dispersant for oilwell operation under temperature ranging of 80°C and 90C° and pressure of 1000 and 3000psi. The formulated composition is tested for fluid loss where the standard has been from 60 to 80 ml. The cement slurry is cured in a 50mm x 50mm x 50mm mold for period of 24 hours. Four manipulating variables were set in formulating the cement slurry namely, the ratio between fly ash and slag to alkali binder, ratio of sodium hydroxide (NaoH) to sodium silicate, molarity of NaoH and amount of dispersant added. After running a set of 16 experiment, sample (12) was found to possess the best rheological properties and fluid loss according to API RP10B. It was found that as the curing temperature and pressure increase, the compressive strength of the formulated geopolymer cement also increased.

The process of cooking oil production generally is started by grating the ripe coconut meat, then pressing the grated meat to obtain coconut milk, and finally heating the coconut milk to obtain the cooking oil. Pressing mechanism to obtain coconut milk is a very important step and decisive in the process of producing cooking oil. The amount of milk produced depends on the pressure applied at the time of pressing grated coconut. The higher the pressure, the more milk is obtained. Some commercial mechanical pressing tools that available in the market are not efficient due to the working steps too much and take long time per cycle of work. The aims of this study was to design and manufacture a power screw squeezer for the collection of coconut milk. Power screw produces a compressive force in the cylinder to push and press the grated coconut until the end of the cylinder while the coconut milk and coconut dregs flow out simultaneously. Screw press was designed using straight shaft configuration with square profile. Performance test was done to investigate the actual capacity and yield of milk produced. The results showed that squeezer of grated coconut worked well with capacity an average of 13,63 kg/h and coconut milk yield of 58%.

This paper presents comparison study of simulation and fabrication characterized two type planar springs at micro–fabricated electromagnetic power generator for an ambient vibration energy harvesting system. The power generator utilized a LASER–machined FR4-PCB planar spring, a copper coil, and NdFeB magnet. In order to change resonant frequency, we developed a gimbal suspension structure for the fabrication of spring. The NdFeB permanent magnet was applied as inertial mass. The system was specially designed to harvest low ambient vibrations from 20 to several hundred hertz and low acceleration. The dimension of fabricated energy harvester had 2.5 x 2.5 cm² in size. In this study we present two different design of cantilever, which is has two and four cantilever, respectively. The different designed given different resonance frequency to the system. The result of simulation giving resonance frequency of two cantilever membrane 22.6 Hz and four cantilever membrane 110.3 Hz. The measurements result has generated 0.135 V with resonance frequency 39 Hz of two cantilever membrane appropriate for human motions, four cantilever membrane has generated 0.174 V with resonance frequency106 Hz appropriate for machine industries.

Punching process is an operation that a scrap is separated from a metal sheet by a punch. Improper setting of punching conditions may lead to excessive of material deformation around edge region (burr), which may weakening the strength of produced part. Analysis of punching mechanics would be beneficial reducing defective part. One of effective analysing tool for this application is Finite Element (FE) method. The aim of this study is to develop reliable FE model for analysis of punching process. The FE model was developed based on 2D. FE result was validated with experimental testing result by comparing burr height. It was found that FE result is -1.79% difference compared to experimental result. Good agreement between FE and experimental result was obtained.

This paper contains numerical analysis of a layered geometric nonlinear flexible shallow shell based on an elastic foundation. Rise of arch in the center of the shell, width, length and type of support are given. The design variable is taken to be the thickness of the shallow shell, the form of the middle surface forming and the characteristic of elastic foundations. Critical force coefficient and stress of shells are calculated by Bubnov-Galerkin. Stress, characteristic of elastic foundations – thickness dependence are presented.

A methodology for shell stability research and determining buckling load, based on the mixed finite element method are proposed. Axisymmetric geometrically nonlinear shallow shells made of orthotropic material are considered. The results of numerical research of stability by changing the shape of shells, ratio of elastic modulus of the material and parameters of the support contour are presented.

The criteria of the buckling of engineering structures in terms of the systems with lumped parameters are discussed in the article. The examples of setting buckling problems and their solutions using Timoshenko and Bryan criteria's, and the criterion of the critical levels of energy are given. The analysis of the compared approaches, their strengths and shortcomings in terms of the single-degree-of-freedom systems are presented.

This research is established for the purpose of the understanding the stability of the acidity of lubricant oil in biogas fuelled engine due to the absence of hydrogen sulfide (H₂S). As was recognized that other than Methane (CH₄), there are also other gas impurities in the biogas such as carbon dioxide (CO₂), hydrogen sulfide (H₂S), moisture (H₂O) and ammonia (NH₃). Due to H₂S contents in the biogas fuel, the engine was found failure. This is caused by corrosion in the combustion chamber due to increase of lubricant acidity. To overcome this problem in practical, the lubricant is increased the pH to basic level with the hope will be decrease to normal value after several time use. Other method is by installing pH measurement sensor in the engine lubricant so that when lubricant is known turn to be acid, then lubricant replacement should be done. In this research, the effect of biogas desulfurization down to zero level to the acidity of lubricant oil in the four stroke engine was carried out with the hope that neutral lubrication oil to be available during running the engine. The result indicates that by eliminating H₂S due desulfurization process, effect on stability and neutrality of pH lubricant. By this method the engine safety can be obtained without often replacement the lubricant oil.

Hydrophobic surfaces were created by coating various substrates (aluminum sheet, soda-lime glass, silicon carbide polishing paper, glass with double-sided adhesive) with paint containing functionalized oxide particles. The paint was created by functionalizing oxide particles (ground ZnO, TiO₂ nanoparticles, or TiO₂ microparticles) with fluorosilane molecules in absolute ethanol. Water contact angle of samples shows that the coated substrate becomes hydrophobic (water contact angle ≥ 90°). Among the oxides that were used, ground ZnO yielded contact angle exemplifying superhydrophobicity (water contact angle ≥ 150°). Scanning electron micrograph of paint-containing TiO₂ nanoparticles shows rough functionalized oxides structures which probably increase the hydrophobicity of the surface.

The combustion characteristic of material in high oxygen concentration is directly related to the safety of elevated oxygen environment similar to oxygen bombs and future spacecraft. In this study, flame front and flame spread rate in high oxygen concentration are discussed. Thermoplastic material polyamide (PA6) and thermosetting material epoxy are selected as comparison material. The variation of flame front over epoxy is more stable than PA6 which has dripping phenomenon during the flame spread process. The flame spread rate of both PA6 and epoxy have a power law with the increasing oxygen concentration.

The present investigation deals with the effect of substrate orientation effect on the growth of thermally oxidized Ge. The thermal oxidation was performed at temperature between 375 and 550°C in dry oxygen ambient under atmospheric pressure. The thickness of thermally oxidized Ge films was measured by spectroscopic ellipsometry and the chemical bonding structures were characterized by using x-ray photoelectron spectroscopy (XPS). No orientation dependence was observed for the oxidation at temperature of 375°C while for oxidation at 490 and 550°C, Ge oxidation and GeO desorption rate of (100) orientation yield higher rate than (111). The larger atomic space of (100) orientation explains the higher oxidation and desorption rate at Ge surface.

The current-voltage characteristics of copper oxide (CuO) - zinc oxide (ZnO) heterojunctions under different illumination intensities were observed in this study. ZnO and CuO films were deposited on separate graphite electrodes via electrophoretic deposition (EPD). The films underwent heat treatment and were physically joined to form the p-n junction. The current-voltage characteristics of the junctions were obtained under forward and reverse bias under different illumination intensities. It was observed that the ZnO-CuO junctions exhibited diode-like behavior in the dark, indicated by the passing of current in forward bias and restricting in reverse bias. Under illumination, the junctions exhibited photodiode-like behavior, with increasing reverse current at greater illumination intensities.

Laminated composite of copper with alumina nanoparticle reinforcements has application such as electrical industries. Electrical junctions should have high electrical, thermal conductivity with good mechanical strength. In this research the layers interface of pure copper were reinforced by alumina nanoparticles. For the production of the composite, first alumina nanoparticles were dispersed on Cu layers by suspension method and then the layers were hot pressed at 950°C under 20 MPa pressure. After composite making, the microstructure, the tensile and impact of these composite were studied. The results showed that by increasing amount of alumina nanoparticles up to 0. 5 wt %, tensile and impact strength were increased and for the composites with more than 0.5 wt % because of agglomeration of nanoparticles, these properties were decreased.

A set of experiments was conducted in a 1/3 scale building model to study the influence of stack effect on the heat feedback to the n-heptane pool fires. The height of opened window and pool size were varied. Results show that the conduction heat feedback fraction slightly decreases and the radiation heat feedback fraction increases with the increase of the strength of stack effect, while the convection heat feedback fraction remains almost invariant.

The effect of replacing carbon black (CB) with surfactant-modified silica clay (SMSC) on hardness and tensile properties of natural rubber (NR) composites was studied using a simplex-lattice design of experiment. SMSC was produced by treating silica clay (SC) with coconut diethanolamine (CDEA) and glycerol monostearate (GMS). Complete replacement of CB with SMSC resulted in the decrease of Shore A hardness and tensile stress at all elongations. At higher CB to SMSC ratio, SMSC modified with CDEA performed better than with GMS. However, at lower CB to SMSC ratio, GMS exhibited larger values in the mechanical properties of NR composites. This can be attributed to the surface morphologies of SMSC and the surface aggregation of surfactant to SC.

Propanethiol solution (0.1 M) in 2-propanol, octanethiol solution (0.1 M) in 2-propanol and 20% (NH₄)₂S solution in water were used to passivate the germanium substrates. HfO₂ thin films of 150 ALD cycles were then deposited on the passivated germanium substrates. The morphology of the thin films was investigated by X-ray diffraction and it was found that the morphology of the thin films was not affected by the chemical treatments. A lower leakage current density was observed in the passivated samples compared with the witness one. In addition, the interface quality and long-time stress reliability of the passivated samples were improved when the samples were annealed in forming gas ambient.

Nickel hydroxide [Ni(OH)₂] structures were successfully grown on carbon cloth via hydrothermal treatment followed by annealing. The Ni(OH)₂ structures grown on carbon cloth were characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analysis. XRD analysis revealed the formation of α and β phases of Ni(OH)₂. Microflowers and interconnected grass-like particles were observed on the surface of the carbon cloth. The as-prepared sample could be a promising material for the fabrication of high energy storage devices because of its unique structures.

Biosorption of heavy metals using marine macroalgae biomass can be an effective process and alternative to conventional methods. Activated carbon was developed from macroalgae (Gracilaria changii) and used as adsorbents for the removal of copper (II) from wastewater. Gracilaria changii based activated carbon (GCBAC) was prepared using muffle furnace at a constant temperature of 300 °C for 1 hour. Batch adsorption experiments were conducted to investigate the effets of important parameters such as pH, contact time, initial metal concentration and adsorbent dosage on the removal of Cu (II) from synthetic aqueous solution. Batch adsorption study shows that removal of Cu (II) using GCBAC relied upon pH, contact time, initial metal concentration and GCBAC dosage. The optimum conditions parameters were found to be pH 6.0, time of 60 minutes and GCBAC dosage of 0.3 g, respectively. Adsorption data was described better by Freundlich isotherm model with R² value of 0.7936. The maximum Cu (II) adsorption capacity of GCBAC was found to be 0.07 mg/g. The experimental adsorption data obtained fitted well into Pseudo-second-order kinetic model, with R² value near unity. Thus, GCBAC can be used as an effective adsorbent for the removal of Cu (II) from aqueous solution.

Currently, non-renewable fossil energy dominates utilization of the world energy need for many applications. Efforts has been developed to find alternative renewable energy sources, due to fossil energy availability is diminishing. And one of renewable energy source is from biomass. The aim of this research is to determine characteristics of the Ampel bamboo (Bambusa vulgaris) as an energy potential of biomass. The Ampel bamboo's characteristics possessed are evaluated based on its chemical composition; moisture, volatile, ash, and fixed carbon through proximate analysis; and also carbon, hydrogen and nitrogen content through ultimate analysis. From the Thermo-gravimetric analysis (TGA) indicates that Ampel bamboo contains of about 18.10% hemicelluloses, 47.75% cellulose and 18.86% lignin. While from the ultimate analysis results in the content of carbon, hydrogen, and Nitrogen of Ampel bamboo are 39.75%, 5.75% and 0% respectively. With such characteristics, it indicates that Ampel bamboo has an attractive potential as a renewable energy source.

Bamboo is one of promising biomass raw materials that has been widely researched, developed, manufactured as activated carbon (AC) and applied in many fields of life. However, there were only a few references associated to the use of bamboo AC as an adsorbent for Adsorbed Natural Gas (ANG) application. The purpose of this study was to characterize chemical, strength and microstructure of two types of local Balinese bamboo that were Tabah bamboo (Gigantochloc Nigrociliata) and Tamblang bamboo (Schizostachyum Brachycladum) as AC source. Characterization was carried out by undertaking proximate, ultimate, tensile tests, Van Soest analysis and microstructure observation. The results have showed that Tabah bamboo has 22.9151 % lignin, 44.9456 % cellulose, 84.56 % volatile and 44.47 % carbon, which were those characteristics higher than Tamblang bamboo. Furthermore, Tabah bamboo also has higher bond density vascular bundles, higher tensile strength (240.85 ± 17.53 Nmm-2) and fracture strength (182.39 ± 17.46 Nmm-2), lower ash (2.92 %), silica (1.84 %) and nitrogen (0.95 %) compared to Tamblang bamboo. Due to such characteristics, Tabah bamboo has greater potential as an AC precursor than Tamblang bamboo.

In this study, activated carbon was developed from sugarcane bagasse and its effectiveness in adsorbing lead (Pb²⁺) ions from synthetic aqueous solution was examined. Sugarcane bagasse activated carbon (SCBA) was developed in a tube furnace at a temperature of 900 °C, a heating rate of 10 °C/min, residence time of 3 hours, and at a nitrogen flow rate of 100 mL/min. Batch adsorption experiments were carried out to investigate the effects of pH and SCBA dosages on the adsorption process. The batch adsorption test showed that extent of Pb²⁺ adsorption by SCBA was dependent upon pH and SCBA dosage. The optimum pH for Pb²⁺ adsorption was found to be at pH 5.0. Maximum Pb²⁺ removal efficiency obtained from the batch studies was 87.3 % at SCBA dosage of 10 g/L. Equilibrium adsorption data was described by Langmuir model with a coefficient of determination (R²) of 0.9508. Maximum adsorption capacity according to Langmuir model was evaluated to be 23.4 mg/g. The adsorption capacity of the SCBA was compared with that of other plant-based adsorbents. SCBA is an effective adsorbent for the removal of Pb²⁺ from aqueous solution.

The present study was performed to investigate the effect of volume fraction of alpha and transformed beta phase on the high-cycle fatigue (HCF) properties of the bimodal titanium Ti6Al4V alloy. The effect of such morphology on mechanical properties was studied using tensile and rotating bending fatigue test as per ASTM standards. Microstructures and fractography of the specimens were studied using optical and scanning electron microscopy (SEM) respectively.Ti6Al4V alloy samples were heat treated to have three distinctive volume fractions of alpha and transformed beta phase. With an increase in quench delay from 30,50 and 70 sec during quenching after solutionizing temperature of 967°C, the volume fraction of alpha was found to be increased from 20% to 67%. Tests on tensile and rotating bending fatigue showed that the specimen with 20% volume fraction of alpha phase exhibited the highest tensile and fatigue strength, however the properties gets deteriorate with increase in volume fraction of alpha.

This work aims to gain a better understanding of fire behaviour and hazards of PV panels under different radiation heat fluxes. The cone calorimeter tests were applied to simulate the situations when the front and back surfaces are exposed to heat flux in a fire, respectively. Through comparison of ignition time, mass loss rate and heat release rate, it is found that the back-up condition is more hazardous than face-up condition. Meanwhile, three key parameters: flashover propensity, total heat release and FED, were introduced to quantitatively illustrate fire hazards of a PV panel.

L6 Steel is used as die material in closed die hot forging process. This material is having some unique properties. These properties are due to its composition. Strain softening is the noticeable property of this material. Due to this in spite of cracking at high stress this material gets plastically deformed and encounters loss in time as well as money. Studies of these properties are necessary to nurture this material at fullest extent. In this paper, numerous experiments have been carried on L6 material to evaluate cyclic Stress - strain behavior as swell as strain-life behavior of the material. Low cycle fatigue test is carried out on MTS fatigue test machine at fully reverse loading condition R=-1. Also strain softening effect on forging metal forming process is explained in detail. The failed samples during low cycle fatigue test further investigated metallurgically on scanning electron microscopy. Based on this study, life estimation of hot forging die is carried out and it's correlation with actual shop floor data is found out. This work also concludes about effect of pre-treatments like nitro-carburizing and surface coating on L6 steel material, to enhance its fatigue life to certain extent.

Copper sulfate salts were embedded on multipurpose paper using simple soaking technique while copper oxide particles were embedded using in-situ technique. In simple soaking technique, the papers were simply soaked in copper sulfate solution in order for the copper salts to be incorporated in the paper. In the in-situ technique, the copper sulfate-embedded papers were soaked in sodium hydroxide solution for reactions to occur that will lead to the formation of copper oxide. Copper sulfate-embedded papers have blue green color while copper oxide-embedded papers have brown color. The copper sulfate-embedded paper shows excellent antimicrobial property against Staphylococcus aureus. Meanwhile, the copper oxide-embedded paper shows small zone of inhibition against Escherichia coli and Staphylococcus aureus.

The experimental data of crack length growth and crack surface displacements and critical stress intensity factor of glued timber members adhesive joints are presented in this paper.The influence on crack growth of cyclic loading, load duration and atmospheric impacts are considered.

Chlorpyrifos, a widely used organophosphate pesticide which can be found in surface water bodies, is harmful for human body. Thus, treating water contaminated with chlorpyrifos is important. In our previous studies, novel Ti/IrO₂–SnO₂ anode was successfully developed for electrochemical degradation of chlorpyrifos in chloride free water. In this study, optimization of previously developed Ti/IrO₂–SnO₂ anode for mineralization of chlorpyrifos was successfully performed through response surface methodology. During the optimization study, two-level factorial design was used to determine the optimal coating solutions concentration for developing the Ti/IrO₂–SnO₂ anode. Cyclic voltammetry and open circuit potential were performed to investigate the electrochemically active surface area and stability of these anodes. The response surface and contour plots show that 0.3 M of [Ir] and 7.5 mM of [Sn] coated electrode has both highest anodic charge and stability. Scanning Electron Microscopic (SEM) images show the evidence of having both compact and porous regions in the surface of the thin film, resulting larger surface area. Within 6 h, the best result for mineralization (55.56%) of chlorpyrifos was obtained with 0.3 M of [Ir] and 7.5 mM of [Sn] coated anode using Total organic Carbon (TOC) analyzer. Therefore, the optimum coating concentration was found as 0.3 M of [Ir] and 7.5 mM of [Sn]. It would require an energy consumption of 6 kWhm^-3.

Polyaniline molecules are embedded on adhesive tape using successive ionic layer adsorption and reaction (SILAR) technique. The infrared spectrum shows the existence of molecular vibrational modes associated with the presence of polyaniline molecules on the sample. With the addition of polyaniline molecules, the conductivity of adhesive tape increases. Surface conductivity increases with number of dipping cycle until it reaches a certain value. Beyond this value, surface conductivity begins to decrease. The surface conductivity of the sample is associated with the connectivity of the embedded polyaniline molecules. The connectivity increases as the number of dipping cycle progresses. Meanwhile, the decrease in surface conductivity is attributed to the eroding of existing embedded structure at higher number of dipping cycle.

Polyaniline-coated kapok (Ceiba pentandra) fibers that were embedded with Cu-based particles were fabricated for antimicrobial application. Kapok fibers were coated with polyaniline molecules using oxidative polymerization. The coated fibers were embedded with copper-based particles using soaking method in prepared CuO suspension. X-ray diffraction (XRD) pattern shows presence of Cu and Cu₂O particles on the modified fibers. Scanning electron microscopy (SEM) supports the presence of embedded particles on the modified fibers. The samples showed antimicrobial activity against Escherichia coli and Staphylococcus aureus.

This study was aimed to determine the carbon monoxide (CO) gas sensing capability of zinc oxide (ZnO) film fabricated by successive ionic layer adsorption and reaction (SILAR) on glass substrate. Films consisting of a mixture of flower-like clusters of ZnO nanorods and nanowires were observed using scanning electron microscopy (SEM). Current-voltage characterization of the samples showed an average resistivity of 13.0 Ω-m. Carbon monoxide gas was synthesized by mixing the required amount of formic acid and excess sulfuric acid to produce CO gas concentrations of 100, 200, 300, 400, and 500 parts per million (ppm) v/v with five trials for each concentration. Two sets of data were obtained. One set consisted of the voltage response of the single film sensor while the other set were obtained from the double film sensor. The voltage response for the single film sensor and the double film sensor showed an average sensitivity of 0.0038 volts per ppm and 0.0024 volts per ppm, respectively. The concentration the single film can detect with a 2V output is 526 ppm while the double film sensor can detect up to 833 ppm with a 2V output. This shows that using the double film sensor is advantageous compared to single film sensor, because of its higher concentration range due to the larger surface area for the gas to interact. Moreover, the measured average resistance for the single film sensor was 10 MΩ while for the double film sensor the average resistance was 5 MΩ.

Glass fiber used as reinforced composite presented excellent properties and was used widely in various environment including cryogenic temperature. The failure strain and surface morphology of glass fiber dipped in the liquid nitrogen and room temperature were measured in the study. Through the comparison of two different environment, results showed the glass fiber present better failure strains compared to those at room temperature, and there are no visible defect in the surface of glass fiber after immerged into the liquid nitrogen. The reduction of failure strain in the room temperature would owe dominantly to the relative humidity, but the temperature just exercised less influence on it.

A set of binary Pb-Al alloys with different Al contents were designed in this work. The mechanical properties and corrosion resistance of Pb-Al alloys were investigated with help of tensile test, Charpy V-notch impact test and salt spray corrosion test (SSCT). And the microstructure was observed by optical microscopy. The results showed that microstructure of all alloys were twin structure, and the twin structure was gradually refined with the increase of Al content. Al dissolved in matrix could significantly improve the tensile strength, impact energy and corrosion resistance. However, a higher content of Al would harm the mechanical properties and corrosion resistance. It may be due to the heterogeneous precipitation of Al rich phase.

Effect of hydrogen on microstructure and the hot flow behavior of the directionally solidified Ti–44Al–6Nb–1Cr (at.%) alloy was studied. Ti–44Al–6Nb–1Cr alloys were prepared by vacuum induction melting (as-cast alloy) and cold crucible directional solidification (CCDS). Effects of hydrogen on the hot deformation behavior were tested on Gleeble-1500D at 1373 K and 1473 K under strain rate of 0.01 s⁻¹. Results show that the volume fraction of B2 phase is increased after CCDS due to the solute distribution. The residual B2 phase in the hydrogenated alloy is more than that in unhydrogenated alloy because hydrogen is beta stabilizing element and stabilizes the B2 phase. The peak stress of the CCDS alloy is higher than that of as-cast alloy at the same deformation condition due to the directional solidified microstructure. Hydrogen can decrease peak stress of the as-cast alloy and CCDS alloy significantly, which is decreased by about 46% and 43% respectively. This is attributed to the hydrogen-promoted dynamic recrystallization and hydrogen-increased the volume fraction of B2 phase.

The deformation mechanism that reflects on the cold workability, of two beta-Ti alloys with chemical compositions of Ti-14Cr and Ti-17Mo in wt. % are studied in this work. The present alloys were solution treated at 900 °C for 1.8 ks. Followed by cold rolling with different reduction ratio from 5% to 30%. The microstructural evolution during cold deformation was followed using optical microscopy, X-ray diffraction and micro hardness. It was observed that the hardness and work hardening rate are affected significantly by the amount of cold deformation for the present Ti-alloys. It is apparent from the intensive microstructural observations that the deformation twinning (TWIP effect) is the dominant deformation mechanism in Ti-17Mo alloy at room temperature. However, the formation of slip bands and extended shear bands (SBs) were observed to be the deformation-induced microstructural features in Ti-14Cr alloy. The XRD analyses also revealed that the stress/strain induced martensitic transformation (TRIP effect) has not activated in the deformed Ti-alloys despite high deformation of 30%.

Zinc oxide-embedded kapok (Ceiba pentandra) papers with antimicrobial property were fabricated. Fabrication of papers from kapok fibers was done using chloroform and sodium chlorite treatments. Meanwhile, embedding of zinc oxide particles on the fabricated kapok papers was done using an in situ method. The said method involved soaking the paper in zinc acetate and sodium hydroxide solutions. The method also involved heat treatment of the sample to fasten the formation of zinc oxide particles. X-ray diffraction (XRD) measurement shows the presence of synthesized ZnO particles on the cellulose fibers while scanning electron microscopy (SEM) revealed the flake-like morphology of the embedded ZnO particles. Agar diffusion test shows that the samples have higher antimicrobial effect against Staphylococcus aureus than Escherichia coli.

Copper-based particles were synthesized using an electroless deposition technique. The said synthesis was done in an aqueous solution by reducing copper oxide powders using hydrazine. In this technique, gelatin was used as protective agent. X-ray Diffraction (XRD) measurement shows that the synthesized sample is composed of cuprous oxide (Cu₂O) and copper (Cu) particles. Scanning Electron Microscopy (SEM) shows the morphology of the synthesized copper-based particles. Antimicrobial test shows that the number of Escherichia coli organisms reduced to 62.06% after 2 minutes of contact with the sample. Likewise, SEM micrographs of the Escherichia coli organisms show that the said organism underwent morphological changes in the presence of the synthesized copper-based particles.

This paper presents the synthesis of cupric hydroxide [Cu(OH)₂] and cupric oxide (CuO) via a simple in situ oxidation of copper (Cu) foil in alkaline solution for electrode materials in pseudocapacitors. Cu(OH)₂ and Cu(OH)₂/CuO film grown on Cu substrate offer binderless and additive-free active materials directly in contact with the current collector. This approach allows more efficient interaction of electrolyte and the active material in terms of charge and mass exchange for higher capacitance. The Cu-based nanomaterials have uniform morphology, and are needle-like and flower-like in structure for Cu(OH)₂ and Cu(OH)₂/CuO, respectively. The fabricated nanostructures exhibit a specific capacitance in the range of 400–2000 F/g.

This study was aimed to determine the carbon monoxide (CO) gas sensing ability of zinc oxide (ZnO) film fabricated by spray pyrolysis on glass substrate heated at 300⁰C using 0.2 M zinc acetate precursor solution. The temperature of the precursor solution was maintained at room temperature. Carbon monoxide gas was synthesized by mixing the required amount of formic acid and excess sulfuric acid in the ratio of 1:6 to produce CO gas concentrations of 100, 200, 300, 400, and 500 parts per million (ppm) v/v. There were five trials for each concentration. The films produced exhibited good sensor characteristics such as high linearity in current voltage relationship and voltage response versus concentration. Electrical characterization using the four-point probe showed a linear relationship between current and voltage with resistivity of 0.49 ohm-cm and R² value of 0.994 The zinc oxide film exhibited a sensitivity of 0.19 Volt per 100 ppm of CO gas and linearity R² value of 0.993.