Table of contents

Preface

The International Conference on Green and Renewable Energy (ICGRER 2016) was held November 14-15^th, 2016 at Solo Paragon Hotel, Surakarta, Central Java, Indonesia. This conference is organized by Faculty of Mathematics & Natural Science, Sebelas Maret University.

The scope of parallel classes are solar energy/solar cells, biomass and bio energy, and miscellaneous product. There are 60 presenters were presented and discussed in plenary and parallel session, therefore, a total 28 manuscripts have been peer reviewed with good quality.

We are pleased to have Prof. Dr. Sri Adiningsih, M.Sc., Ph.D (Chairman of the Presidential Advisory Council) as our outstanding keynote speaker. We also glad ti have our invited speakers Prof. Renate Egan (University of New South Wales Australian PV Institute, Solinno Pty, Ltd), Dr. Adhi Wibowo (Direktur PPTEK R&D EBTKE Kementerian ESDM), Ir. Hj. Sripeni Inten Chayani, M (President Director PT. Indonesia Power), Prof. Dr. Ir. Kamaruddin Abdullah (Universitas Darma Persada), and William Papet (Business Development at MPS Consortium).

We express our gratitude to participants from all researchers and students for join this conference. We also appreciate for sponsors, reviewers, and all member of the organizing committee which prepare this conference. Our gratitude also goes to the IOP Publisher for cooperation in prepare this proceeding. We do realize that the success of the conference depends on both participants and who have worked with us.

Prof. Ari Handono Ramelan

Chairman of ICGRER 2016

Dean of Faculty Mathematics & Natural Sciences

All papers published in this volume of IOP Conference Series: Earth and Environmental Science 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.

Coaxial vacuum tube solar collectors can generate heat up to 80°C is possibly used for ethanol distillation process that required temperature 79°C only. This study reviews the performance of coaxial collector vacuum tube used for ethanol distillation process. This experimental research was conducted in a closed space using a halogen lamp as a solar radiation simulator. We had done on three different of the radiation values, i.e. 998 W/m², 878 W/m² and 782 W/m². The pressure levels of vacuum tube collector cavity in the research were 1; 0.5; 0.31; 0.179; and 0.043 atmospheres. The Research upgraded the 30% of ethanol to produce the concentration of 77% after distillation. The result shows that the performance of coaxial collector vacuum tube used for ethanol distillation process has the negative correlation to the level of the collector tube cavity pressure. The productivity will increase while the collector tube cavity pressure decreased. Therefore, the collector efficiency has the negative correlation also to the level of collector tube cavity pressure. The best performance achieved when it operated at a pressure of 0.043 atmosphere with radiation intensity 878 W / m², and the value of efficiency is 57.8%.

Synthesis of TiO₂ nanorods was conducted through mechanochemical of ball milling at speed of 175 rpm for 5 hours and strong base 12 M NaOH reaction by hydrothermal at 150°C overnight on variation annealing at 400, 500, and 600°C. Material characterization were performed by X-Ray Diffraction (XRD), Transmission Electron Microscoe (SEM), and Surface Area Analyzer (SAA). Strong base reaction by hydrothermal showed the presence of anatase, brookite, and rutile phase for annealing up to 400°C. The diffraction pattern of annealing at 500 and 600°C contain peaks of both brookite and rutile phase. Morphology transformation of TiO₂ to form nanorods TiO₂ was showed by rod-shape from TEM micrographs and increase surface area into 111.9 m²/g.

Bond-engineering as applied to semiconductor materials refers to the manipulation of the energy bands in order to control charge transfer processes in a device. When the device in question is a photoelectrochemical cell, the charges affected by drift become the focus of the study. The ideal band gap of semiconductors for enhancement of photocatalyst activity can be lowered to match with visible light absorption and the location of conduction Band (CB) should be raised to meet the reducing capacity. Otherwise, by the addition of the chromofor organic dyes, the wide-band gab can be influences by interacation resulting between TiO2 surface and the dyes. We have done the impruvisation wide-band gap of TiO2 by the addition of organic chromophore dye, and the addition of transition metal dopand. The TiO2 morphology influence the light absorption as well as the surface modification. The organic chromophore dye was syntesized by formation complexes compound of Co(PAR)(SiPA)(PAR)= 4-(2-piridylazoresorcinol), SiPA = Silyl propil amine). The result showed that the chromophore groups adsorbed onto TiO2 surface can increase the visible light absorption of wide-band gab semiconductor. Initial absorption of a chromophore will affect light penetration into the material surfaces. The use of photonic material as a solar cell shows this phenomenon clearly from the IPCE (incident photon to current conversion efficiency) measurement data. Organic chromophore dyes of Co(PAR)(SiPA) exhibited the long wavelength absorption character compared to the N719 dye (from Dyesol).

Photoanode of dye sensitized solar cell (DSSC) plays an important role as electron transport media to accept photogenerated electron from excited state of dye. There are several physical properties that are required from photoanode of DSSC. It should be highly transparent, have large surface area, has a conduction band lower than LUMO of dye molecule, has high charge carrier mobility and finally has a good stability in redox electrolyte process. In this work, DSSC with structure FTO/ZnO nanorod/TiO₂ mesoporous/Ru-dye/gel electrolyte/ Pt/FTO has been fabricated. In order to modified the structures of photoanode, ZnO nanorod was grown on aluminium doped ZnO seed layer by variation concentration of Al (0 wt%, 0.5 wt% and 1.0 wt%). Zinc nitrate hexahydrate and hexamethylenetetramine used as raw materials for ZnO nanorod growth solution and deposited by self-assembly methods on FTO/Al doped ZnO seed layer. It is then followed by deposition of titania (TiO₂) paste by screen printing methods. DSSC parameters i.e. ideally factor (n), series resistance (R_S), and shunt resistance (R_SH) was derived from current density-voltage (I-V) curve using the simplify equation of ideal diode model. The influences of ZnO photoanode structures to the solar cell performance will be completely discussed.

Modification of TiO₂ nanorods through the addition of aminopropyltrimethoxysilane (APTMS) for enhancement of efficiency of solar cells has been studied. Synthesis of TiO₂ nanorods was conducted through two major stages of mechanochemical and hydrothermal refluxing at a temperature of 120 °C for 24 hours on various concentration of NaOH. Material characterizations were performed by X-Ray Diffraction (XRD), Fourrier Transform Infrared (FTIR) and Transmission Electron Microscope (TEM). Mechanochemical treatment by ball milling showed that the TiO₂ phase changed from anatase into brookite and it decreased of TiO₂ crystals size. Morphology transformation of TiO₂ to form TiO₂ nanorods was showed by rod-shaped from TEM micrographs which are characteristic of the nanorods. FTIR spectra confirmed that amine group of aminopropyltrimethoxysilane (APTMS) were successfully grafted onto the TiO₂ nanorods surface. Sensitization of TiO₂ used Ruthenium complexes N3 (N3=cis-bis(isothiocyanato) bis(2,2'-bipyridyl-4,4'-dicarboxylato ruthenium (II)) were able to increase the uptake of TiO₂ material to the visible region due to the absorption of visible light by N3 complex-APTMS. Sensitized TiO₂ nanorods were prepared for Dye Sensitized Solar Cell (DSSCs) photoanode. The maximum results of the DSSCs (Dye Sensitized Solar Cell) performance was showed that TiO₂ material modified by 10 % (v/v) APTMS capable increase efficiency of DSSCs.

Composite of TiO₂ NRs - ZnO were synthesized for DSSCs photoanode materials. TiO₂ NRs was synthesized from TiO₂ anatase by mechanochemical technique using ball milling process with agitation speed of 1000 rpm. While, the further hydrothermal refluxing process was conducted at 120°C under various concentration of NaOH in aqueous solution. The starting material of ZnO was prepared from ZnSO₄.7H₂O as a precursor. The hydrothermal treated TiO₂ was added to the ZnO powder in a certain composition of 1:1, 1:2 and 2:1 (w/w), and the mixtures were then annealed at 400°C. The resulting material was characterized by X-ray diffraction (XRD), Surface area analyzer (SAA), Transmission electron microscopy (TEM), and Thermogravimetry/Differential thermal analysis (TG/DTA). The TiO₂ revolution occurs from anatase phase into brookite phase. Rutile TiO₂ phase was increasing when the NaOH was added at about 12 M. Nanograf of TEM showed the optimum condition for the formation of TiO₂ NRs was obtained when 12 M NaOH was used. Structural transformation to 1D nanorods of TiO₂ capable increase surface area up to 79 m²/g. TiO₂ NRs–ZnO composite was prepared from TiO₂ NRs and ZnO using comparation of TiO₂ NRs: ZnO = 1:1, 1:2, dan 2:1. Anatase phase TiO₂ as a single phase TiO₂ was obtained in the TiO₂–ZnO composite (1:1 w/w) upon heating the sample until 400°C. Difference TiO₂ NRs-ZnO composite materials were investigated as good photovoltaic materials. Evaluation of the performance of DSSCs was conducted by I-V Keithley 2602A measurement indicate that photoanode built of TiO₂ NRs - ZnO thin film has a higher solar cell efficiency than that of TiO₂ thin film photoanode.

In southern beach of West Java, Indonesia, there are many villagers live as fishermen. They use small boats for fishing, in one to three days. Therefore, they need a fish preservation system. Fortunately, the area has high potential of solar and wind energy. This paper presents the design of a hybrid solar and wind energy harvester to power a refrigerator in the fishing boat. The refrigerator should keep the fish in 2 – 4 °C. The energy needed is 720 Wh daily. In the area, the daily average wind velocity is 4.27 m/s and the sun irradiation is 672 W/m². The design combined two 100W solar panels and a 300W wind turbine. The testing showed that the solar panels can harvest 815 – 817 Wh of energy, while the wind turbine can harvest 43 – 62 Wh of energy daily. Therefore, the system can fulfil the energy requirement in fishing boat, although the solar panels were more dominant. To install the wind turbine on the fishing-boat, a computational design had been conducted. The boat hydrostatic dimension was measured to determine its stability condition. To reach a stable equilibrium condition, the wind turbine should be installed no more than 1.7 m of height.

The wind speed in the southern beach of West Java Indonesia is quite promising for wind energy harvesting. A field survey reported that the wind speed reached 10 m/s, while the average recorded in a year is about 4.7 m/s. In this study, two vertical axis wind turbines (VAWT) were compared to be used in that area through calculation as well as experiments. The experiments measured that the turbines can produce about 7.82W and 2.33W of electricity respectively. These experiments are compared with theoretical calculation to obtain the performance of both turbines used. The coefficient of performance (cp) experimentally is 0.09 for Turbine 1 (hybrid Savonius-Darrieus rotor) and 0.14 for Turbine 2 (Savonius rotor). While, rotor's mechanical performance Cpr, obtained theoritically through calculation, is 0.36 for Turbine 1 and 0.12 for Turbine 2. These results are analysed from mechanical and electrical view.

Palm shell is a potential source of raw materials for the produce of activated carbon as biosorbent for quite large numbers. The purpose of this study is to produce activated carbon qualified Indonesian Industrial Standard (SNI), which will be used as biosorbent to purify the impurities in the off gas petroleum refinery products. Stages of manufacture of activated carbon include carbonization, activation of chemistry and physics. Carbonization of activated carbon is done at a temperature of 400°C followed by chemical activation with active agent KOH and ZnCl₂. Then the physical activation is done by flowing N₂ gas for 1 hour at 850°C and followed by gas flow through the CO₂ for 1 hour at 850°C. Research results indicate that activation of the active agent KOH produce activated carbon is better than using the active agent ZnCl₂. The use of KOH as an active agent to produce activated carbon with a water content of 13.6%, ash content of 9.4%, iodine number of 884 mg/g and a surface area of 1115 m²/g. While the use of ZnCl₂ as the active agent to produce activated carbon with a water content of 14.5%, total ash content of 9.0%, iodine number 648 mg/g and a surface area of 743 m²/g.

Clinoptilolite zeolites were chemically modified with chitosan (Chit) and magnetic iron oxide nanoparticles (Fe₃O₄NPs) were synthesized for removal of mercury from liquid condensate hydrocarbon. The mercury content was in liquid hydrocarbon which was measured by Lumex mercury analyzer. The performance of sorbents based on zeolites modified chitosan and magnetic nanoparticles were examined on the real liquid condensate hydrocarbon. Removal of mercury using a prestine clinoptilolite zeolites, and zeolites modified chitosan (zeolites-Chit) were ∼4.5, and ∼35%, respectively. The effects of magnetic nanoparticles in zeolites-Chit sorbents were significant to reduce the mercury content in liquid condensate hydrocarbon which were from ∼63 to ∼66%. Increasing the mass ratio of Fe₃O₄ that influenced to the BET surface area of natural zeolites. Zeolites-Chit-Fe₃O₄NPs as an efficient sorbents are potential ideal to remove mercury in hydrocarbon for practical applications.

A study with entitled Seepage Zone Identification At Sutami Dam By Means Of Geoelectrical Resistivity Data has been conducted. The aim of this study is to get the distribution of seepage zones in the Sutami dam body. Data acquisition has been done by using Oyo-EL McOhm Model 2119C equipment on the tracks along the side of the dam body, both downstream (exhaust) side for first and upstream (reservoir) side for second with pseudodepth section dipole-dipole configuration. Each track has a length of 400m and 380m respectively. The distance between the point electrode consists of 1 track with space (a) is 10m (n=8) and 3 tracks with a space (a) is 20m (n=8). Based on the results of data processing obtained are low resistivity values (ρ ≤ 9.57 Ωm), the moderate resistivity value (9.57 Ωm < ρ ≤ 320 Ωm), and high resistivity (ρ > 320 Ωm). The distribution of fracture zones associated with seepage zones for Sutami dam distributed over the surface to depth of 8-18 m, both upstream (reservoir) or downstream (exhaust) indicated by resistivity values 0.922 Ωm to 9.57 Ωm. The results of the 3D data processing indicates that the fracture zone is also distributed between the upstream (reservoir) and downstream (exhaust) of the Sutami dam body.

One source of alternative energy substitute for petroleum raw materials is renewable vegetable oils known as biodiesel. Biodiesel can be produced from microalgae, since it was more efficient and environmentally friendly. Scenedesmus dimorphus (Turpin) Kützing was developed as a source of biodiesel since it had potential of high lipid production. The aims of this research were to know the rate of growth of Scenedesmus dimorphus in different lighting and the optimimum light intensity for biomass and lipid production. This research used a completely randomized design consisting of 3 treatments with 3 replications. Treatments in this research were the light intensity, i.e. 7,500, 10,000, and 12,500 lux. Scenedesmus dimorphus was grew in Bold's Basal Medium (BBM). Parameters observed in this research were the cell number, biomass and lipid production of S. dimorphus. Data were analyzed by ANOVA followed by DMRT 5%. The results showed that the optimum growth rate of S. dimorphus was in the intensity of 12,500 lux that was 100.80 x 10⁶ cells.ml^-1. The optimum production of biomass and lipids was in treatment 12,500 lux i.e; 1.1407 g.L^-1 and 0.2520 g.L^-1 (22.28% dry weight).

The production of biosurfactant by Pseudomonas putida has been studied. P. putida FNCC 0071 was grown in the nutrient broth medium supplemented with NaCl and crude palm oil (CPO). The effect of CPO concentration and fermentation time on the biosurfactant production were evaluated. The biosurfactant production was evaluated every 24 h for 10 days by optical density, surface tension and emulsification index. The best culture medium was found to be medium containing 5% v/v of CPO with 5 days of incubation time. The biosurfactant was identified as rhamnolipids.

Cassava peels waste contains, cellulose which is quite high at 43.626%, this is a potential candidate as a raw for bioethanol production. The purpose of this study was to determine the performance of the enzymatic hydrolysis, microbiological (Effective microbe) and fermentation in cassava peel waste is known from the results of quantitative measurement of multiple ethanol parameters (DNS Test, pH, ethanol concentration). This research was carried out in stages, the first stage is hydrolysis with completely randomized design with single factor variation of the catalyst, consisting of three levels ie cellulase enzymes, multienzyme and effective microbial EM4. The second stage is fermentation with factorial randomized block design, consisting of three groups of variations of catalyst, and has two factors: variations of fermipan levels 1, 2, 3% and the duration of fermentation, 2,4,6 days. The parameters in the test is a reducing sugar, pH and concentration of ethanol. The results showed that variation of hydrolysis treatment, fermentation time, and fermipan levels has real effect on the fermentation process. On average the highest ethanol content obtained from the treatment with multienzyme addition, with the addition of 2% fermipan levels and on the 2nd day of fermentation that is equal to 3.76%.

A synthesis allophone-like had been done from aluminum nitrate nonahidrat (Al (NO₃)₃.9H₂O) and tetraethyl orthosilicate (TEOS). This study aims to determine synthesis of allophane-like based on variations in the ratio of Al/Si is applied as an adsorbent for the lead (Pb) metal. The study was conducted with ratio variation Al/Si 0.5; 0.75; 1; 1.25 and 1.5 from solution volume nonahidrat (Al (NO₃)₃.9H₂O) and TEOS at pH 3-4 calcined at temperature of 400°C. The adsorption type is determined by the adsorption isotherm. The results of the research shows that allophane-like can be synthetized from a solution of nonahidrat (Al (NO₃)₃.9H₂O) and TEOS with a variation of the ratio of Al/Si 0.5; 0.75; 1; 1.25 and 1.5. Allophane-like has function groups of -OH group; spanning asymmetrical form of O-Si-O/O-Al-O; Si-O/Al-O bending vibration and relatively weak absorption which strengthen their OH group. The results of allophane-like adsorption capacity of 1.61 mg/g in the ratio Al/Si of 1.5 at pH 4 with a contact time of 30 minutes with a percentage of 80.77% adsorption. The adsorptions of Pb heavy metals with allophane-like tend to follow the type of adsorption isotherms of Freundlich or physics.

Road damage caused as a result of the traffic load and environment. One method to improve the road condition is from an overlay. But the new layer on the top of the pavement structure is thick enough and elevate the surface of the pavement, so it will cause some impact on the user safety and engineering. The use of a thin layer of hot mix asphalt is an alternative to anticipate the thickness problem. Crumb rubber is a waste material that has a flexible nature, these materials are used as an aggregate replacement in the hot mix asphalt thin layer. The research was conducted to find the optimum bitumen content and optimum crumb rubber content on asphalt mixtures by the Marshall procedure. Finally, it was concluded that the addition of crumb rubber in a thin layer of hot mix asphalt indicates the better the interlocking between aggregates so that gave the better Marshall stability, the higher the flow rate, the lower the marshall quotient, reduce the void ratio. The results show that the addition of crumb rubber content as an aggregate replacement leads to the use of less optimum bitumen content.

Buton asphalt (asbuton) could not be utilized optimally in Indonesia. Asbuton utilization rate was still low because the processed product of asbuton still have impracticable form in the term of use and also requiring high processing costs. This research aimed to obtain asphalt products from asbuton practical for be used through the extraction process and not requiring expensive processing cost. This research was done with experimental method in laboratory. The composition of emulsify asbuton were 5/20 grain, premium, texapon, HCl, and aquades. Solid phase was the mixture asbuton 5/20 grain and premium with 3 minutes mixing time. Liquid phase consisted texapon, HCl and aquades. The aging process was done after solid phase mixing process in order to reaction and tie of solid phase mixed become more optimal for high solubility level of asphalt production. Aging variable time were 30, 60, 90, 120, and 150 minutes. Solid and liquid phase was mixed for emulsify asbuton production, then extracted for 25 minutes. Solubility level of asphalt, water level, and asphalt characteristic was tested at extraction result of emulsify asbuton with most optimum ashphal level. The result of analysis tested data asphalt solubility level at extract asbuton resulted 94.77% on 120 minutes aging variable time. Water level test resulted water content reduction on emulsify asbuton more long time on occurring of aging solid phase. Examination of asphalt characteristic at extraction result of emulsify asbuton with optimum asphalt solubility level, obtain specimen that have rigid and strong texture in order that examination result have not sufficient ductility and penetration value.

Indonesia imports high amount of Fuel Oil. Although Indonesia has abundant amount of natural gas reserve, the obstacle lies within the process of natural gas storage itself. In order to create a safe repository, the ANG (Adsorbed Natural Gas) technology is planned. ANG technology in itself has been researched much to manufacture PET-based activated carbon for natural gas storage, but ANG still has several drawbacks. This study begins with making preparations for the equipment and materials that will be used, by characterizing the natural gas, measuring the empty volume, and degassing. The next step will be to examine the adsorption process. The maximum storage capacity obtained in this study for a temperature of 27°C and pressure of 35 bar is 0.0586 kg/kg, while for the desorption process, a maximum value for desorption efficiency was obtained on 35°C temperature with a value of 73.39%.

Damar asphalt is one type of bioaspal which is a mixture with the main ingredient is a resin as a binder and cooking oil as a solvent. One major drawback of this damar asphalt is the low ductility. To improve the ductility values, then use the added material Filler. Filler serves as a divider between the impurities with damar asphalt, increases ductility and increase the ability of cohesion or bonding between the particles of material damar asphalt. The purpose of this study was to determine damar asphalt modifications to the properties in accordance with the properties of damar asphalt test specifications based on the value of penetration. This method uses some variant on material such as powder bricks and fly ash as a binder. Solvent in constituent used oil and used cooking oil. It also added the polymer latex up to 10% at intervals of 2%. The best composition of damar asphalt materials were obtained with gum rosin, Fly Ash, Oil and Latex. Damar asphalt modification damar asphalt optimum mix of resin (100g pure resin or resin chunk + 350g powder), Fly Ash powder (150g), cooking oil (205g), and latex 4%, ductility increased from 63.5 cm to 119.5 cm, the value of the flash point was originally at temperature of 240 °C to 260 °C, damar asphalt penetration of 68.2 dmm to 43 dmm, and the value of density decreases from 1.01 g / cm³ to 0.99 g / cm³. Damar asphalt at these modifications meet the specifications in terms of solubility in trichlore ethylene is equal to 99.5%, and also meet the affinity of damar asphalt at 99%. With the optimum value, damar asphalt could be categorized as bitumen 40/60 penetration.

Public expectations of Central Java, which is very high on demand fulfillment, especially road infrastructure as outlined in the number of complaints and community expectations tweeter, Short Mail Massage (SMS), e-mail and public reports from various media, Highways Department of Central Java province requires development model of environmental management in the implementation of a routine way by involving the community in order to fulfill the conditions of a representative, may serve road users safely and comfortably. This study used survey method with SEM analysis and SWOT with Latent Independent Variable (X), namely; Public Participation in the regulation, development, construction and supervision of road (PSM); Public behavior in the utilization of the road (PMJ) Provincial Road Service (PJP); Safety in the Provincial Road (KJP); Integrated Management System (SMT) and latent dependent variable (Y) routine maintenance of the provincial road that is integrated with the environmental management system and involve the participation of the community (MML). The result showed the implementation of routine maintenance of road conditions in Central Java province has yet to implement an environmental management by involving the community; Therefore developed environmental management model with the results of H1: Community Participation (PSM) has positive influence on the Model of Environmental Management (MML); H2: Behavior Society in Jalan Utilization (PMJ) positive effect on Model Environmental Management (MML); H3: Provincial Road Service (PJP) positive effect on Model Environmental Management (MML); H4: Safety in the Provincial Road (KJP) positive effect on Model Environmental Management (MML); H5: Integrated Management System (SMT) has positive influence on the Model of Environmental Management (MML). From the analysis obtained formulation model describing the relationship / influence of the independent variables PSM, PMJ, PJP, KJP, and SMT on the dependent variable MML as follows: MML = 0.13 + 0.07 PSM PJP PMJ + 0.09 + 0.19 + 0.48 KJP SMT + e

The oxide dispersed strengthened (ODS) alloys steel developed as structure material for nuclear power plants (NPP) has good resistant against creep due to their unique microstructure. Microscopy investigation on the microstructure formation during alloying process especially at the early stages was carried out to study the correlation between structure and property of ODS alloys. This was possible thanks to the arc plasma sintering (APS) device which can simulate the time dependent alloying processes. The ODS sample with composition of 88 wt.% Fe and 12 wt.% Cr powder dispersed with 1 wt.% ZrO2 nano powder was mixed in a high energy milling, isostatic compressed to form sample coins and then alloyed in APS. The Scanning Electron Microscope (SEM) with X-ray Diffraction Spectroscopy (EDX) line scan and mapping was used to characterize the microstructure and elemental composition distribution of the samples. The alloying process with unification of each Fe and Cr phase continued by the alloying formation of Fe-Cr by inter-diffusion of both Fe and Cr and followed by the improvement of the mechanical properties of hardness.

It has been done a research to determine the solar thermal collector efficiency of the flat plate collector. The testing of the collector was conducted on 30^th November 2005, 1^st, 3^rd, 5^th, 6^th, 7^th December 2005 with the variation of distance between one glass covers were varied from 3 cm, 6 cm, and 9 cm; and with inclination angle variation of collector from 10°, 20°, 30°, and 40°. Solar thermal collectors absorb the radiant energy from the sun and convert it to heat between the bottom glass cover and absorbing plates in the collector. Parameters which influence on the collector performance include distance between plate collector with glass covers and the inclination angle. It was found that the difference between output-input temperatures is the highest on a distance of 3 cm and inclination angle of 10°. This is influenced that inclination angle 10° more close to zenith angle. The solar thermal collector efficiency is not a constant; The solar collector efficiency depends on solar radiation intensity, input-output temperature difference and air flow. The smaller the inclination angle of solar collector, the higher the absorption radiation. If inclination angle of collector same with zenith angle, so the absorption radiation will maximum.

This study focused on the effect of a compatibilizer addition, maleic anhydrides (MAH) on mechanical, thermal and water absorption properties of oil palm empty fruit bunches (EFB) fiber reinforced recycled polypropylene (rPP) biocomposites. The double steps grafting process were conducted by incorporated MAH on both rPP and EFB to improve the surface adhesion between these materials, to result in a good mechanical properties as well as biocompatibility to nature. The chemical test was carried out using FTIR (Fourier Transform Infra-Red) spectroscopy technique to evaluated grafting process. The mechanical test was investigated and found that the addition of 10 phr MAH to both rPP and EFB improved mechanical strength of the biocomposites higher than another formulas. In this study, thermal properties of biocomposites also characterized. Water absorption (WA) analysis showed the presence of EFB fiber increased the water uptake of the material.

Surface properties are important factors that determine the performance of ultrafiltration membranes. This study aimed to investigate the effects of clay addition on the surface properties and membrane permeability of PVDF (poly-vinylidene fluoride) membranes. Three types of clay with different particle size were used in this study, namely montmorillonite-MMT, bentonite-BNT and cloisite 15A-CLS. The PVDF-clay composite membranes were prepared by phase inversion method using PEG as additive. The hydrophobicity of membrane surface was characterized by contact angle. The membrane permeability was determined by dead- end ultrafiltration with a trans-membrane pressure of 2 bars. In contact angle measurement, water contact angle of composite membranes is higher than PVDF membrane. The addition of clays decreased water flux but increased of Dextran rejection. The PVDF-BNT composite membranes reach highest Dextran rejection value of about 93%. The type and particle size of clay affected the hydrophobicity of membrane surface and determined the resulting membrane structure as well as the membrane performance.

The new complex of [Cu(benz)₃(H₂O)₂Cl]Cl has been synthesized in 1:4 mole ratio of CuCl₂·2H₂O and ethyl-p-aminobenzoate (benz) in ethanol at room temperature. The complex was characterized by UV-Vis and infrared spectroscopy, Atomic Absorption Spectroscopy (AAS), thermal analysis, magnetic measurement and molar conductivity. Infrared spectra indicated that benz was coordinated to the metal ion through nitrogen of primary amine group. Water molecules and chloride ion were also coordinated to Cu(II). CuCl₂·2H₂O, benz, and Cu(II) complex were screened for investigating in vitro antibacterial activity against Staphylococcus aureus and Escherichia coli using a modified Kirby-Bauer method.

Composites contain double filler material which act as reinforcement and flame retardants of recycled polypropylene (rPP)/kaolin(Kao)/palm oil empty bunch fiber (PEBF) have been succesfully prepared. The composites were synthesized through reactively solution method, using coupling agent PP-g-AA and compatibilizer DVB. The effect of double filler [Kao/PEBF] were investigated flexural strength (FS), inflammability, and morphology. Mechanical testing result in accordance to ASTM D790, the FS of rPP/DVB/PP-g-AA/Kao+ZB/PEBF composite was 48% higher than that of rPP matrix. Moreover, flexural modulus (FM) was significantly improved by 56% as compared to that of rPP matrix. The scanning electron images (SEM) shown good dispersion of [Ka/PEBF] and good filler-matrix interaction. The inflammability testing result which is tested using ASTM D635, showed that the flame resistance of rPP/DVB/PP-g-AA/Kao+ZB/PEBF composite was improve by increasing of time to ignition (TTI) about 857% and burning rate (BR) decreasing to 66% compared to the raw material rPP matrix. In the same time, the addition of 20% (w/w) PEBF as a second filler to form rPP/DVB/PP-g-AA/Kao+ZB/PEBF composites (F5) is able to increase: the FS by 17.5%, the FM by 19%, the TTI by 7.6% and the BR by 3.7% compared to the composite without PEBF (F2).

Polyvinylideneflouride (PVDF) is a good polymeric material for preparing ultrafiltration and microfiltration membranes due to its high mechanical properties and chemical resistance. The objective of this work is to study the effects of PVDF concentration on the membrane properties such as mechanical strength, permeability of water and permselectivity of T-500 and T-2000 dextran solutions. These membranes were also characterized by contact angle determination and its morphology was observed by scanning electron microscopy (SEM). From the experimental data, it can be concluded that PVDF concentration affects the surface properties, permeability and permselectivity of the produced membranes. Higher PVDF concentrations results in higher hydrophobicity, mechanical properties and rejection towards T-500 and T-2000 dextrans, but lower water flux.

A state function is a thermodynamic function which relates various macroscopically measurable properties of a system (state variable) describing the state of matter under a given set of physical conditions. A good understanding of a biogas state function plays a very important role in an effort to maximize biogas processes and to help predicting combation performance. This paper presents a step by step process of an experimental study aimed at determining the equation of state of cow dung biogas. The equation was derived from the data obtained from the experimental results of compressibility (κ) and expansivity (β) following the general form of gas state equation dV = βdT + κdP. In this equation, dV is gas volume variation, dT is temperature variation, and dP is pressure variation. From these results, we formulated a unique state equation from which the biogas critical temperature (T_c) and critical pressure were then determined (T_c = 266.7 K, P_c = 5096647.5 Pa).