Page 30 (data 871 to 900 of 1092) | Displayed ini 30 data/page
<< PREV 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 NEXT >>

871	Material Science	ABS-376
Melting Dynamics of Gold Nanoparticle and Thin Film Riser Fahdiran (a*), Iwan Sugihartono (a), Erfan Handoko (a), Setia Budi (b) a) Department of Physics, State University of Jakarta, Jalan Rawamangun Muka, Jakarta Timur, 13220, Indonesia * riser-fahdiran[at]unj.ac.id b) Department of Chemistry, State University of Jakarta, Jalan Rawamangun Muka, Jakarta Timur, 13220, Indonesia Abstract We studied the melting dynamics of Gold in the form of nanoparticle and thin film. The nanoparticle diameter is comparable with the thin film thickness, i.e. 10 nm. The systems are heated from room temperature up to slightly above melting point, Tm = 1400 K. The evolution of the atoms in each system is followed using Molecular Dynamics (MD) scheme up to 20 ps. Thermodynamics analysis indicated that thin film is suppressed by the pressure greater than nanoparticle. Structural analysis compared with Common Neighbor Analysis (CNA) expressed the condition that melting evolution occurred almost in the same time between both cases. Keywords: molecular dynamics; nanoparticle; thin film; metal; melting Share Link | Plain Format | Corresponding Author (Riser Fahdiran)

872	Material Science	ABS-377
Size Dependencies on Melting Dynamics of Gold Nanoparticle and Thin Film Riser Fahdiran (a*), Iwan Sugihartono (a), Erfan Handoko (a), Setia Budi (b) a) Department of Physics, State University of Jakarta, Jalan Rawamangun Muka, Jakarta Timur, 13220, Indonesia * riser-fahdiran[at]unj.ac.id b) Department of Chemistry, State University of Jakarta, Jalan Rawamangun Muka, Jakarta Timur, 13220, Indonesia Abstract We explore the size dependencies of melting dynamics of Gold in the form of nanoparticle and thin film. The sizes are 5 nm, 10 nm and 20 nm which is comparable between nanoparticle diameter and thin film thickness. The systems are treated by increasing temperature from 300 K to 1400 K. Molecular Dynamics (MD) scheme is employed to follow the trajectories of the systems up to 30 ps. Structure factor and pair distribution function analysis indicated that the melting is suppressed by the increasing size. Common Neighbor Analysis (CNA) confirmed the suppression from local crystal structure of every system. Keywords: molecular dynamics; nanoparticle; thin film; metal; melting; size Share Link | Plain Format | Corresponding Author (Riser Fahdiran)

873	Material Science	ABS-891
Magnetic Properties of Natural Hematite (Fe2O3) Extracted from Iron Ore by Co-Precipitation Method Zulkarnain Jalil, Adi Rahwanto, Mustanir, Akhyar Hasan, Erfan Handoko Universitas Syiah Kuala Abstract Nowadays, iron oxide plays a crucial role in various applications and intensively investigated, especially its application in magnetic materials. Unfortunately, economically is very low income since the exported of iron ore in the form of lumps of pure rock. In this paper, the mineral composition and magnetic behavior of nano Fe2O3 of iron ore from Lhoong mining area, Aceh province were studied. The iron ore was firstly prepared by mechanical milling method and then followed by co-precipitation method to obtain the pure hematite. The mineral and chemical compositions of samples were investigated by XRD and XRF analysis tests. The XRF test showed that the Lhoong iron ore contain Fe2O3 (93.88%) in association with other isomorphous impurities, such as SiO2, MnO, and Al2O3 in varying proportions. Compare to XRD results, it was consistent with XRF, the phase compositions of iron ore were mainly hematite (Fe2O3). The XRD revealed that hematite was the major mineral components in the Lhoong iron ores. SEM observation was shown fine crystalline structure of Lhoong iron ore after milling process. The main mineral morphology was micro-crystalline in agglomerate forms. The magnetic properties of the samples after milling was showed the increasing in the remanent (Br) and coercivity (Hc). This increasing can be explained that nano-Fe2O3 phase after milling for 20 hours plays an important role in the magnetic behavior of Lhoong iron ore. It is understood that the longer milling time is sufficient to complete the transformation of hematite (Fe2O3) to magnetite (Fe3O4). Keywords: Hematite, iron ore, nano-minerals, co-precipitation, ball milling Share Link | Plain Format | Corresponding Author (Zulkarnain Jalil)

874	Material Science	ABS-636
Waste of Rice Straw as a Renewable Energy: An Overview of the Potential Availability, Content, and Production Process Ana A*, I Khoerunnisa, M Muktiarni, V Dwiyanti, A Maosul *Faculty of Technology and Vocational Education, Universitas Pendidikan Indonesia Jl. Dr. Setiabudhi No 229, Bandung 40154, Jawa Barat, Indonesia Abstract Indonesias crude oil balance has been in a deficit during the last decade. The increase in domestic crude oil consumption is inversely proportional to its production. New crude oil reserves are needed to anticipate a prolonged energy crisis. This study examines the potential of agricultural waste as a renewable energy source that can be produced in terms of availability, content, and production processes. A systematic literature review was chosen as the method of this study. The biomass content in agricultural waste can be used as bioenergy raw material, one of which is lignocellulose. Rice waste is agricultural waste that is available in large quantities and contains high lignocellulose. Through biochemical processes, lignocellulose is broken down into lignin in the pretreatment process. Cellulose is converted into glucose using acids in the process of hydrolysis. The conversion of glucose into ethanol is carried out in the fermentation process. Bioethanol is purified by a distillation process to increase the ethanol content. The high content of lignocellulose in rice waste and high annual production in various regions in Indonesia is a major potential. Comparison of the availability of agricultural waste as raw material for bioenergy and the biomass it contains is discussed Keywords: rice straw, agricultural waste, renewable energy, national defense Share Link | Plain Format | Corresponding Author (INDAH KHOERUNNISA)

875	Material Science	ABS-384
ANALYSIS OF DIFFERENCES IN TYPE OF INSECT IN EDELWEIS JAVA (ANAPHALIS JAVANICA) IN TEGAL BUNGBRUN PAPANDAYAN MOUNTAIN GARUT DISTRICT H Hernawan, R Abdussalam, D B I Taofik, A A R Susila Institut Pendidikan Indonesia Garut Abstract This research is raining to find out the insect species, diversity index, abundance value, evenness value, dominance index, and insect density value on Javanese Edelweiss (Anaphalis javanica) in Tegal Bungbrun, Mount Papandayan. In this study the method used was purposive sampling using quadratic and Pitfal-trap techniques. The results obtained as many as 13 species belonging to 10 families and 5 orders with a total number of individuals is 235. The calculation results obtained, namely the diversity index at Tegal Bungbrun, Mount Papandayan of 1.0216, including at a moderate level, the highest abundance of insect species among 13 species, namely Apis andreniformis species with a value of 0.1957 are at abundant levels. Evenness value is 0.9171 which means that the insect evenness is in a stable condition. Insect dominance value of 1.9969 included in low dominance, dominated by Apis andreniformis of 0.3915. A density value of 9.4 is included in the low density category. Keywords: Insects, Diversity, Abundance, Density, Evenness, Domination Share Link | Plain Format | Corresponding Author (Hudiana Hernawan)

876	Material Science	ABS-385
ANALYSIS OF PELECYPODA ECOLOGY INDEX IN RANCABUAYA BEACH GARUT DISTRICT H Hernawan, N U Hasanah, D B I Taofik, A A R Susila Institut Pendidikan Indonesia Garut Abstract This study aims to determine the Pelecypoda species and Pelecypoda Ecological Index values include diversity, abundance, evenness, dominance and density in Rancabuaya Beach Garut District. The method used is descriptive method with purposive sampling technique, Line transect and Quadrat transect. Sampling was carried out by dividing the study area into three observation stations totaling 90 samples. Observations were obtained, Pelecypoda species as many as 12 species including: Barbatia foliata, Antigona puerpera, Antigona materna, Anadara turonica, Cardita aviculina, Anodontia vesicula, Gafrarium pectinatum, Antigona puerpera, Antigona materna, Anadara turonica, Cardita aviculina, Anodontia vesicula, Gafrarium pectinatum, Anigontia edentpera, Antigona materna, Anadara turonica, Cardita aviculina, Anodontia vesicula, Gafrarium pectinatum, Anigontia edentperula, Anigontia edentula Septifer bilocularis, Tellina scobinata, Tridacna maxima, and Anadara antiquata. The results of the analysis of diversity index 0.0069-0.1596 are in the low category, an abundance index of 0.3-35.3% are in the average category enough, evenness index 0-0.0753 evenness is in a depressed condition, 0-0,12456 which is in the low category and the density index ranges from 0.1 to 13.2 is in the low category. Keywords: Analysis, Ecological Index, Pelecypoda, Rancabuaya Beach Share Link | Plain Format | Corresponding Author (Hudiana Hernawan)

877	Material Science	ABS-646
Enhanced Performance of UV Photodetector of MoS2 Quantum Dots-decorated ZnO Nanorods Nur Ajrina Putri(a), Vivi Fauzia(a)*, Isnaeni(b), Ismira Lewa(b), Cuk Imawan(a) (a) Department of Physics, Faculty of Mathematics and Natural Sciences, University of Indonesia Depok 16424, Indonesia (b) Research Center for Physics, Indonesia Institute of Sciences, Kawasan PUSPIPTEK, Serpong, Tangerang Selatan, Banten 15314, Indonesia Abstract Two-dimensional transition metal dichalcogenides such as molybdenum disulfide (MoS2) have attracted great attention due to their unique optical, electrical and chemical properties. MoS2 quantum dots (QDs) exhibit strong quantum confinement, high surface area and notable active edge sites compared to their bulk. In this work, MoS2 QDs were attached on the surface of ZnO nanorods (NRs) grown on interdigitated ITO substrates and then used as photodetector. MoS2 QDs were synthesized by a new ultrafast way pulsed laser ablation (PLA) in liquid method and then spincoated on the surface of ZnO NRs. The pristine ZnO and ZnO/MoS2 QDs photodetector were investigated under UV and visible light (325 nm, 505 nm and 635 nm) with the bias voltage -5 V to 5 V. The results show that the decoration of ZnO NRs by MoS2 QDs could enhance the sensitivity, responsivity and detectivity under UV irradiation. This may due to the decrease of dark current as the result of passivation of surface defects of ZnO NRs by MoS2 QDs. Keywords: Zinc Oxide; MoS2; photodetector; quantum dot; two-dimensional Share Link | Plain Format | Corresponding Author (Nur Ajrina Putri)

878	Material Science	ABS-393
Reduced Graphene Oxide-based Transparent Conductive Films: The Preleminary Review of Reductant Materials Agent Vina Iasha, Endang Wahyudiana, Moh. Syarif Sumantri, Arita Marini*, Bramianto Setiawan** *Department of Postgraduate Elementary Education, Universitas Negeri Jakarta, Indonesia **Department of Elementary Education Teacher, Universitas PGRI Adi Buana, Indonesia Abstract The rising demand for optoelectronic devices makes the research widely develop in recent years. Flexibility, stretchability, and energy efficiency are important material properties in the devices, especially for Transparent Conductive Films (TCFs). Graphene is one of the highly promising materials for TCF due to its properties, such as outstanding electrical conductivity, good in chemical and thermal stability, high optical transparency, and remarkable mechanical flexibility. However, the development of these materials has limited to laboratory research. The difficulty of material synthesize for mass production is one of a challenge for the researcher to develop it. Many methods were used to develop graphene material such as Chemical Vapor Deposition (CVD), Epitaxial growth, and mechanical and chemical exfoliation graphene. The modified Hummer Method is one of the promising chemical exfoliation methods that produced graphite into graphene oxide. This method still needs one step to reduce the oxygen content on graphene oxide because it gives a poor effect both in electrical conductivity and optical transparency. Reductant materials are needed to solve the problem. This review presents the reductant materials that can be used to reduce the oxygen content of graphene oxide that support in the fabrication of TCFs. Keywords: reduced graphene oxide, thin film, reductant materials agent Share Link | Plain Format | Corresponding Author (Vina Iasha)

879	Material Science	ABS-654
Effect of Ball Diameter on Particle size of Mechanicallay Alloyed Al-10wt.%Ti Powders Adolf Asih Supriyanto, Deni Kurnia, Feri Siswoyo Hadisantoso Prodi Mekatronika Politeknik Enjinering Indorama Purwakarta Abstract Particle size of Al-10%wt.Ti powders due to the influence of ball diameter have been carried out using mechanical alloying techniques. The milling device used consisted of a Fritsch Pulverisette-5 planetary type ball mill with the rotational speed of about 360 rpm and balls size of 15 and 20 mm. The materials used are stearic acid which was used as a process control agent, aluminum and titanium powders. A mixture of aluminum and titanium powders has the composition of Al-10wt.%Ti. The Al-10wt.%Ti powders, stearic acid and stainless steel balls were added to the Fritsch Pulverisette-5 planetary in the argon gas environment. The weight ratio of stainless steel balls to the Al-10wt.%Ti powder was 20 : 1. The mixing time process was carried out for 2, 5, 10, 15, 20 and 30 hours, respectively. To avoid increasing temperature suddenly, the milling process was rested for 30 minutes every 2.5 hours of milling. XRD, SEM and EDX were used to observe changes in the structure and morphology of the powder during the milling process. The results obtained using XRD showed that the peaks of Ti begin disappear with the increasing of milling time. This phenomenon indicates the forming alloying of Ti atoms in the Al matrix. The results obtained using SEM show that the longer the mixing time, the finer the size of the Al-10% by weight of Ti alloy. The EDX results showed that the powder obtained was Al-Ti binary alloy powder without any impurities. Keywords: Al-10%wt.Ti powder, mechanical alloying, XRD, SEM, EDX Share Link | Plain Format | Corresponding Author (Adolf Asih Supriyanto)

880	Material Science	ABS-404
High purity silica from rice husk ash as catalyst in Mg-based hydrogen storage material Zulkarnain Jalil, Ismail Ismail, Adi Rahwanto, Malahayati, Farid Mulana, Erfan Handoko Universitas Syiah Kuala, Banda Aceh Abstract Magnesium hydrides (MgH2) is one of the most promising material for hydrogen storage application, since its reversible and able to store hydrogen in large amounts of 7.6wt%. In this study, nickel and silicon di-oxide catalysts were used to reduce the operational temperature of MgH2. In this work, we introduce the green catalyst of silicon di-oxide which was extracted from local rice husks ash. The purity of silica obtaine 98%. The composition of MgH2 + 5wt% Ni X wt% SiO2 (x=3,5,10,15) was prepared by mechanical alloying technique, by soft milling time. The characterization have been done by X-ray diffraction (XRD), scanning electron microscopy (SEM) for their phase composition and morphology, respectively. The desorption kinetics measured with gravimetric method. XRD results indicate a decrease in particle size with short milling time. MgH2 was obtained as the main phase followed by Ni and SiO2. SEM results showed that with the milling process, the particle is homogeneous. The nanopowders of Mg-based hydrides was succesfully produced by using mechanical alloying method. Keywords: natural silica, rice husk ash, catalyst, hydrogen storage, milling Share Link | Plain Format | Corresponding Author (Zulkarnain Jalil)

881	Material Science	ABS-156
Synthesize Method Improvement of Polyvinyl Acetate Emulsion Through Emulsion Polymerization Technique in Aqueous Solution A. Jaya (a), M. A. Elita Hafizah (a), A. Manaf (a*), Suparno (a), Andreas (b) (a) Postgraduate Program of Materials Science, Faculty of Mathematics and Natural Science, Universitas Indonesia, Jl. Salemba Raya No.4, Jakarta 10430, Indonesia (b) Indonesian Institute of Sciences, LIPI, Komplek PUSPITEK, Serpong, Banten 15314, Indonesia Abstract A series of experiments have been carried out and reported. In this report describes the stages of the polymerization reaction during emulsion Polyvinyl Acetate (PVAc) synthesis. PVAc was synthesized from the Vinyl Acetate Monomer (VAM) with Ammonium Peroxydisulphate (APS) as an inorganic thermal initiator in the aqueous media under reaction temperature was keep at 65-75°C by agitation speed was 300 rpm respectively during 4 hours of reaction time. The protective colloid agents and several types of surfactants were added to improve the performance of the obtained emulsion PVAc. The polymerization reaction was carried out without the addition of a protective colloid agents nor the surfactants was produced the emulsion PVAc with the properties of Solid Content 0.89%, Density 1.02 g/ml, viscocity 0.0033 Poise, pH 2.8, Conductivity 12 ms respectively. While the polymerization reaction involved protective colloid agents by using Polyvinyl Alcohol (PVOH) was obtained properties of emulsion PVAc with Solid Content 4.36%, Density 1.17 g/ml, viscocity 0.0216 Poise, pH 2.8, and Conductivity 10 ms respectively. The same thing was shown when the surfactant was presence in polymerization reaction. The emulsion PVAc was synthesized with nonionic surfactant has Solid Content 8.20%, Density 1.17 g/ml, viscocity 0.0099 Poise, pH 2.8, and Conductivity 7 ms, the result is better rather than synthesized with anionic surfactant has Solid Content 2.65%, Density 1.13 g/ml, viscocity 0.0068 Poise, pH 2.8, and Conductivity 11 ms. According to the preliminary observations obtained, the appearance of emulsion PVAc is better when the protective colloid agents and surfactant is presence rather than without additional those substances. The physical properties of emulsion were depended on the additional of protective colloid agents and surfactant. In additional the complete reaction which indicated by solid content value was obtained from emulsion when the additional substances were present. All the testing parameters were observed by using Viscometer Ostwald, Pycnometer, pH Meter, FTIR Spectrophotometer, Conductometer and other supporting testing to explain the polymerization reaction stage of synthesis emulsion PVAc. Keywords: Emulsion, emulsion polymerization, polyvinyl acetate, polyvinyl alcohol, anionic surfactant, protective colloid agent. Share Link | Plain Format | Corresponding Author (Adam Jaya)

882	Material Science	ABS-172
Absorbance Dependence of ZnO Thin Films on Post-heating Temperature Iwan Sugihartono1*, Ayusa Rizka Putri1, Tan Swee Tiam2, Ucu Cahyana3, Erfan Handoko1, Setia Budi3, Riser Fahdiran1, Cecep Rustana1, Anggara Budi Susila1, Esmar Budi1 1Program Studi Fisika, FMIPA, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Rawamangun, Jakarta Timur, Indonesia 13220 2School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia 3Program Studi Kimia, FMIPA, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Rawamangun, Jakarta Timur, Indonesia 13220 Abstract We have prepared ZnO thin films on indium tin oxide (ITO) glasses using dip-coating at room temperature. Post-heating has been performed by different temperatures i.e. 450 oC, 500 oC, 550 oC, and 600 oC under atmosphere ambient. The effect of post-heating temperature on the structural properties and absorbance of ZnO thin films have been investigated. Structurally, we observed ZnO thin films under a post-heating temperature of 450 oC, 500 oC, and 550 oC have polycrystalline hexagonal wurtzite structure. Meanwhile, at the temperature of 600 oC, it has an amorphous structure. Optical absorbance spectra of ZnO thin films confirmed that amorphous structure has the highest intensity compared to polycrystalline hexagonal wurtzite structure. Keywords: ZnO thin films, post heating, structural, absorbance Share Link | Plain Format | Corresponding Author (Iwan Sugihartono)

883	Material Science	ABS-943
SYNTHESIS AND CHARACTERIZATION OF COMPOSITE MAGNETITE-BENTONITE FROM INDONESIAN LOCAL MINERALS Moersilah, Arif Rahman, Edit Alanas, and Rosmalia Department of Chemistry, Faculty of Mathematics and Science, State University of Jakarta, Jl. Rawamangun Muka, Jakarta Timur, Jakarta, Indonesia Abstract The use of modified natural materials as adsorbents has been widely reported. In this study, synthesize and characterization of magnetite-bentonite composite composites from Indonesian local minerals was reported. Composites are synthesized by inserting iron ion into the bentonite layers with a mole ratio of 1: 1 Fe2+ / Fe3+ ions; 1: 1.5; and 1: 2, hereinafter referred to as composite A, composite B, and composite C respectively. All composites were then calcined at a temperature of 400 oC for 1 hour. Iron oxide formed in the area between bentonite layers has a magnetite structure and have high thermal stability. This can be seen from the diffraction pattern obtained from XRD analysis. The specific surface area of the composite also increased compared to pure bentonite. Before being modified, pure bentonite had a surface area of 47,824 m2/g and after insertion of iron oxide there was an increase. Composite A is 87.482 m2/g composite B is 83.774 m2/g and composite C is 98.336 m2/g. Keywords: composite, magnetit, Bentonit from Indonesian Share Link | Plain Format | Corresponding Author (Moersilah Moersilah)

884	Material Science	ABS-694
The Properties of Crystallinity and Surface Morphology Of Composite Cholesteryl Acrylate-ITO nanoparticle was Added Poly Ethylene Glicol Afrizal, Setia Budi, Muhammad Ismail, Gracia, Intan, Bryan Department of Chemistry Universitas Negeri Jakarta Abstract Composite of cholesteryl acrylate-ITO nanoparticle was added Poly Ethilene Glycol (PEG) has been success synthesized. This research focus for study Properties of Crystallinity and Surface Morphology Of Composite Cholesteryl Acrylate-ITO nanoparticle was Added Poly Ethylene Glycol. XRD pattern of that product showed special peak at 2θ in 21o and confirmed nematic phasa. Therefore added PEG can be change the structures liquid crystal of cholesteryl acrylate. Prosen crystallinity from analysis by XRD that variations of PEG. Result this research PEG (0,001) is 8,14%; PEG(0,002) is 12,41%; PEG(0,003) is 14,85%; PEG (0,004) is 7,11; and PEG (0,005) is 8,66%. SEM image of composite cholesteryl acrylate-ITO nanoparticle that added PEG 0,003 showed picture rod and chain make crosslinked, that indications succecsfull photopolymerizations process. Much more PEG was added change directions of crystal the composite. That conditions making polymer to be micelle and can be effect to conductivity value because that polymer forming an aggregate. Keywords: Composite of cholesteryl acrylate-ITO nanoparticle was added Poly Ethilene Glycol (PEG) has been success synthesized. This research focus for study Properties of Crystallinity and Surface Morphology Of Cholesteryl Acrylate; ITO nanoparticle; Poly Ethylene Glycol; crystallinity Share Link | Plain Format | Corresponding Author (Afrizal Afrizal)

885	Material Science	ABS-959
Nutrient Content of Fiber Feed in Rural Dairy Farm, Lembang Sub-District, West Bandung District Atikah Nur Hamidah (a*), Despal (b), Epi Taufik (b) a) Magister Student at Faculty of Animal Science, IPB University, Agatis Street, Babakan, Dramaga, Bogor, West Java 16680, Indonesia *atikahhamidah26[at]gmail.com b) Faculty of Animal Science, IPB University, Agatis Street, Babakan, Dramaga, Bogor, West Java 16680, Indonesia Abstract Dairy farms in Lembang provide fiber feed independently. Unlike the case of complete feed (concentrate) that has been sold by livestock cooperatives in Lembang, which could be easily obtained. This study aims to explore and understand the source of fiber feed and its nutritional value that is commonly used in Lembang dairy farms. This research was conducted on 50 rural dairy farms in Lembang located in West Bandung District. This study implements a purposive sampling technique for the selection of the dairy farm location. Samples of fiber feed in the dairy farms were taken using a simple random sampling technique. Analysis for samples using NIRS (near infrared reflectance spectroscopy) to obtain data on dry matter (DM), ash, crude protein (CP), fat, crude fiber (CF), neutral detergent fiber (NDF), and acid detergent fiber (ADF) of fiber feed content. The data acquired is analyzed using descriptive analysis. The result reveals that the fiber feed that has been given to the dairy cows was cultivated grass, natural grass, legumes, and plant residue that entirely supplied from neighborhood area (≤ 30 km) which has varying nutrient content (DM 2.78-38.75%, ash 9.22-28.12%DM, CP 8.90-31.02%DM, Fat 1.96-7.23%DM, CF 13.10-32.44%DM, NDF 19.95-60.68%DM, and ADF 17.17-42.62%DM). Keywords: Dairy farms, fiber feed, nutrient content Share Link | Plain Format | Corresponding Author (Atikah Nur Hamidah)

886	Material Science	ABS-705
Combination of Polyaniline and Graphene Oxide as Counter Electrode Composite in Dye-Sensitized Solar Cells Risa Rahmawati Sunarya(1,2), Veinardi Suendo(*1), Rahmat Hidayat(3) 1Inorganic and Physical Chemistry Research Division, FMIPA, Institut Teknologi Bandung 2Chemistry Education Study Programme, FTK, UIN Sunan Gunung Djati Bandung 3Magnetic and Photonic Physics Research Division, FMIPA, Institut Teknologi Bandung *Email: vsuendo[at]chem.itb.ac.id Abstract The usage of polyaniline (PANI) and graphene oxide (GO) composites film as counter electrode in DSSC was demonstrated. PANI was prepared using rapid mixing method in 0 ℃ for 24 hours. While GO was synthesized using sonication-assisted oxidation of graphite. PANI and GO was blended to produce PANI/GO composites. PANI/GO composites was deposited on synthetic graphite substrate laminated onto glass and applied as the counter electrode of dye sensitized solar cells (DSSC). PANI and GO has electrostatic interaction, π-π stacking interaction and hydrogen bonding that accelerate charge transfer in counter electrode. The optimum performance was obtained for PANI/GO of 3:1 w/w. Here, fill factor (FF), open circuit current (Voc), optimum short circuit current density (Jsc) and overall power conversion efficiency (PCE) under AM 1.5 100 mW cm−2 illumination are 43,2%, 0.64 Volt, 7.308 mA/cm2, and 2.25%, respectively. PANI/GO composites were characterized using Raman spectrometer, fourier transform infrared (FTIR) spectrometer, scanning electron microscope (SEM) and solar simulator. Keywords: Dye-sensitized solar cells, emeraldine salt polyaniline, chemically-exfoliated graphene oxide, PANI/GO composite, Platinum-free counter electrode Share Link | Plain Format | Corresponding Author (Risa Rahmawati Sunarya)

887	Material Science	ABS-204
EVALUATION OF KOH ACTIVATOR CONCENTRATION VARIATION ON THE PHYSICAL PROPERTIES OF SUPERCAPASITOR ELECTRODES FROM CARBON ACTIVATED OF COCOA PODS Yuli Yetri1, Mursida2, Dahyunir Dahlan2, Muldarisnur2 1Politeknik Negeri Padang, Kampus Limau Manis Padang, Indonesia 2Department of Physics, Andalas University, Padang, Indonesia Abstract The study of making activated carbon from the cocoa pods which will be used as supercapacitor electrodes has been successfully made with KOH activators of 0.3 M and 0.4 M at 7000C. Activated carbon electrodes are made by a combination of chemical activation and physical activation methods. Physical properties were tested by measuring the density, X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The technique of preparing carbon electrodes starts from pre-carbonization, milling, chemical activation, pellet making, carbonization, and physical activation. Analysis of dimensions, and density in the manufacture of carbon electrodes showed the mass, diameter, thickness and density of the electrodes decreased along with the addition of KOH concentration from 0.3 M to 0.4 M. XRD measurement data obtained values of 2θ in the range of 23,569o-24,747o for the reflection plane 002 and 44,634o-44,781o for the reflection plane 100. X-ray diffraction curve analysis shows that the sample 0.4 M 700oC has a smaller microcrystalline dimension (Lc) value and lattice distance than the 0.3 M 700oC sample, so it can be indicated that the surface area of the sample is 0.4 M 700oC greater than the 0.3M 700oC sample. With an increase in the surface area of the sample, there is an indication that the activated carbon of cocoa pods can be used as a supercapacitor electrode as a renewable energy source. Keywords: Physical properties, Cocoa pods, Activated Carbon, Electrodes, Supercapacitors Share Link | Plain Format | Corresponding Author (Yuli Yetri)

888	Material Science	ABS-208
Utilization of Prilled Fat on Milk Production and Milk Quality Fed to Lactating Dairy Cows Soraya Rizki Sanidita (a), Yuli Retnani (a*), Despal (a) a) Graduate School of Animal Nutrition and Feed Technology, IPB University Kampus IPB, Jl. Agatis, Dramaga, Bogor, West Java 16680, Indonesia *yuli.retnani[at]yahoo.com Abstract The objective was to determine the effects of supplemental prilled fat in lactating dairy cows diet on milk production and milk quality. There hasnt been any novel information about the effect of different content of palmitic acid in the prilled fat. The study conducted for 49 days, consisted of 42 days of adaptation and 7 days of data collection. Sixteen mid-lactation multiparous Friesian Holstein cows were assigned in completely randomized block design experiment of four dietary treatments and four groups. The treatments were: basal diet (T1), basal diet + 2% of prilled fat with 75% of palmitic acid (T2), basal diet + 2% of prilled fat with 85% of palmitic acid (T3), and basal diet + 2% of prilled fat with 95% of palmitic acid (T4). The basal diet that used containing approximately 60% forages and 40% grains. The total dry matter intake resulted highest in T2 (P<0.05) with average 17.42 kg/head/day, whereas, the milk production was not affected. The milk quality analyzed were total solid (TS), %fat, %protein, %laktosa and solid non-fat (SNF). The %fat resulted the best in T2 with average 4.22% (P<0.05), while there were not any significantly differences in TS, %protein, %laktosa and SNF. Keywords: prilled fat; dairy cows; palmitic acid Share Link | Plain Format | Corresponding Author (Soraya Rizki Sanidita)

889	Material Science	ABS-464
Digestive Evaluation of Tofu Dregs as Influenced by Fermentation and Tannin Present in the Material Ensiled Zulkarnain1, Erika B. Laconi2, Anuraga Jayanegara2, Ahmad Sofyan3 1Graduate School of Nutrition and Feed Science, Faculty of Animal Science, IPB University, Bogor 16680, Indonesia; 2Department of Nutrition and Feed Technology, Faculty of Animal Science, IPB University, Bogor 16680, Indonesia; 3Research Unit for Natural Product Technology (BPTBA), Indonesian Institute of Science (LIPI) Abstract Tofu dregs is one of the high-protein feed ingredients and it is highly palatable for livestock particularly ruminants. However, tofu dregs has a main disadvantage, i.e., easily to deteriorate due to its high water and protein contents. Fermentation of tofu dregs may be applied in order to prevent such deterioration. The aim of this experiment was to evaluate tofu dregs as influenced by fermentation and tannin extract from acacia bark on in vitro rumen fermentation and digestibility parameters. The experimental treatments were: NK (tofu dregs without fermentation and 0% tannin), NT (tofu dregs without fermentation and 2% tannin), FK (tofu dregs with fermentation and 0% tannin) and FT (tofu dregs with fermentation and 2% tannin). Data were analyzed by analysis of variance according to a randomized complete block design with four treatments and four replications. Results revealed that both dry matter (DMD) and organic matter digestibility (OMD) were not significantly different among the treatments. The NH3 parameter was significantly different (p<0.05) due to fermentation and tannin addition to tofu dregs. Meanwhile, protozoa as one of the microbes which live in the rumen was not influenced by fermentation and tannin addition. In conclusion, fermentation and tannin treatment on tofu dregs do not cause any negative effect of in vitro rumen fermentation and digestibility. Keywords: Tofu dregs, Fermentation, Tannin, Fermentation Products, Digestibility Share Link | Plain Format | Corresponding Author (Zulkarnain Zulkarnain)

890	Material Science	ABS-982
Study on the microstructure and mechanical properties during cold rolling and annealing process of Cu-30Zn-1Al-1Mn alloys Imam Basori*, Gabriel David Krishartadi, Sirojuddin and Syamsuir Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Jakarta 13220, Indonesia *unimam_r_one[at]yahoo.com Abstract This research was conducted to determine the effect of cold rolling and annealing process on the microstructure and mechanical properties of the Cu-30Zn-1Al-1Mn brass alloy produced by gravity casting. Samples were cold rolled with deformation levels of 20%, 40% and 70% and followed by annealing process with temperature variations of 300oC, 400oC, 500oC, and 600oC for 30 minutes. Sample characterization includes chemical composition analysis, microstructure observation and hardness testing. The results illustrate that the Cu-30Zn-1Al-1Mn brass alloy shows the appearance of α and β phases. The cold rolling process with a deformation levels of 20% and 40% promote the formation of a slip and twinning mechanism. On the other hand, samples with a 70% deformation level are dominated by shear bands. The annealing process induces the phenomena of recovery, recrystallization and process of grain growth. The higher the deformation level, the faster the recrystallization process. Furthermore, the smaller the grain size, the higher the sample hardness. Keywords: Cold rolling;annealing; brass alloys; shear band; slip Share Link | Plain Format | Corresponding Author (IMAM BASORI)

891	Material Science	ABS-732
Application of Laser Induced Plasma Spectroscopy to detect contaminants in food Mangasi Alion Marpaung1), Erfan Handoko1), Marincan Pardede2) 1) Program studi fisika, FMIPA, Universitas Negeri Jakarta, jl. Rawamangun muka, Rawamangun, Jakarta Timur 13220 Abstract We have conducted experiment using Nd-YAG laser at fundamental mode to generate plasma from meatballs sample that was contained borax as a contaminant with various concentration. The plasma emission has been investigated by using A gated Optical Multichannel Analyzer (OMA). The boron emission line (B I 249.7 nm) has been used as indicator of existence of borax in meatballs food. The optimum conditions of plasma generation in this experiment were at 83 mJ laser energy, 20 Torr helium surrounding gas pressure, 1s OMA delay. At these optimum conditions, the existence of 0.5 % (w) borax could be detected by means of boron emission line. These experimental results shows that laser induced plasma spectroscopy is applicable as a tool for emission spectrochemical analysis of material sample even soft or hard sample. Keywords: Laser Induced Plasma Spectroscopy; contaminants; food Share Link | Plain Format | Corresponding Author (Mangasi Alion Marpaung)

892	Material Science	ABS-484
Synthesis of ZnO/FA Composite for Methylene Blue Decolorization Eko Prabowo Hadisantoso, Zoraya Desti Ayu, Popy Listiani, Soni Setiadji Department of Chemistry, Faculty Science and Technology, UIN Sunan Gunung Djati Bandung, Jl. A.H. Nasution No. 105 Bandung, West Java 40614, Indonesia Abstract In this research, a ZnO/FA composite was successfully synthesized for the photocatalytic treatment of methylene blue. ZnO was obtained from Zn-C battery waste by precipitation method. Zinc metal from battery waste was separated, cleaned and dissolve in hydrochloric acid to obtain Zinc chloride solution. After adding some base until pH = 10, white precipitation was formed. This precipitate was filtered out and calcinated at 400 C for 4 hours to obtained ZnO. Fly Ash (FA) was obtained from coal combustion waste. Fly ash was cleaned and drying at 105 C for 3 hours. The ZnO/FA composites were synthesized by solid dispersion method using acetone as a medium with a various composition of ZnO:FA = 20:80; 40:60; 60:40; 80,20 in percentage. The XRD data show that the ZnO/FA composite was successfully synthesized. The SEM photo’s show that different morphology where more ZnO in the composite, the FA particles will be increasingly encased with ZnO particles. Photocatalytic performance studies of ZnO/FA composites for decolorization of methylene blue were carried out in various compositions, exposure times, substrate concentrations and mass composites. The optimum decolorization was found in 40:60 composition, 3 hour irradiation time, 5 ppm concentration of methylene blue, and 250 mg of photocatalyst mass. Keywords: battery waste, fly ash, composite, photocatalytic, methylene blue, decolorization Share Link | Plain Format | Corresponding Author (Eko Prabowo Hadisantoso)

893	Material Science	ABS-486
Synthesis of Fe2O3 Nanoparticles From Battery Waste as Photocatalyst for Methylene Blue Decolorization Eko Prabowo Hadisantoso, Fitri Rahmawati, Vina Amalia, Soni Setiadji Department of Chemistry, Faculty Science and Technology, UIN Sunan Gunung Djati Bandung, Jl. A.H. Nasution No. 105 Bandung, West Java 40614, Indonesia Abstract Zinc-Carbon (Zn-C) batteries occupy the largest current Indonesian market share of disposable batteries, resulting in a large number of Zn-C batteries waste needed to be considered. In this paper, Fe2O3 nanoparticles form Zn-C batteries waste was prepared by precipitation method. The iron from the outer layer of Zn-C battery waste was cleaned and dissolved in hydrochloric acid. Brown dark precipitation, Fe(OH)3, will be obtained after adding ammonium hydroxide. This precipitate was calcinated at 700 C for 4 hours to obtain Fe2O3. The XRD analysis result shows that Fe2O3 successfully synthesized. From the XRD data, synthesized Fe2O3 has typical peaks at 2 = 24,124, 33,156, 35,619, 40,852, 49,452 and 54,064, with the highest intensity at 33,156 and 35,619. SEM photo shows that there is an agglomeration of the synthesized Fe2O3 nanoparticles. The Fe2O3 nanoparticles are spherical in shape and have sizes ranging from 33 to 36 nm based on the Debey Scherrer equation. The synthesized Fe2O3 was used for the photocatalytic treatment of methylene blue with several variations, which is a mass variation of Fe2O3, irradiation time, and methylene blue concentration. The largest percentage of decolorization was obtained 50,12% in condition using 0,09 grams of Fe2O3 nanoparticles with 15 mL of 10 ppm methylene blue solution and 3 hours irradiation time. Keywords: Fe2O3; photocatalyst; battery waste; nanoparticles; methylene blue Share Link | Plain Format | Corresponding Author (Eko Prabowo Hadisantoso)

894	Material Science	ABS-497
Silica Addition Effect on Optical Properties of Organometal Halide Perovskite-PMMA Composite Film Ea Cahya Septia Mahen1,2, Bebeh Wahid Nuryadin3, A H Aimon1, Suprijadi1,4 and Ferry Iskandar1,4* U1Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung, Indonesia 40132 2Department of Physics Education, Faculty of Education and Teaching, UIN Sunan Gunung Djati Bandung, Jl. A. H. Nasution 105 Bandung Indonesia 40614, 3Department of Physics, Faculty of Science and Technology, UIN Sunan Gunung Djati Bandung, Jl. A. H. Nasution 105 Bandung Indonesia 40614 4Research Center for Nanosciences and Nanotechnology, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung, Indonesia 40132 Abstract The effect of silica (SiO2) addition on optical properties of organometal halide perovskite PMMA composite film was studied. The organometal halide perovskite, MAPbBr3, was synthesized using ligand assisted re-precipitation (LARP) method, and then was compose to PMMA and SiO2 directly to make composite films. The absorbances, transmittances, and photoluminescence (PL) spectrum of the samples were characterized using UV Vis and PL spectroscopy. The result shows that both samples showed a semi-transparent film with 80 % transmittance and multiple excitonic peaks on absorption spectra with different intensity. This reveals a mixture of perovskite nanostructures with different morphologies and sizes. The addition of SiO2 in the composite leads strong exciton absorption at short wavelength resulting in a blueshift in the PL spectra. Keywords: Perovskite, PMMA, Silica Share Link | Plain Format | Corresponding Author (Ea Cahya Septia Mahen)

895	Mathematics	ABS-261
Students Mathematical Reasoning and Curiosity Through Autograph-Aided Make a Match Learning Iyon Maryono, Ganda Risalam & Agus Hikmat Syaf UIN Sunan Gunung Djati Bandung School of Postragraduate Studies, Universitas Pendidikan Indonesia Abstract The purpose of this study was to examine the students mathematical reasoning and curiosity skills through autograph-aided make a match learning. This study uses quasi-experimental methods with pre-test and post-test control group designs. The subjects consisted of 23 students as the experimental class and 22 students as the control class from a population of 90 Multimedia class students in one of the vocational high schools. The experimental class obtained a make a match learning model aided by autograph, while the control class obtained a conventional learning model. The results showed that increasing mathematical reasoning ability of students who obtained Autograph-aided Make a Match learning was better than students who obtained conventional learning. Increased mathematical curiosity of students who get Autograph aided Make a Match learning is better than students who get conventional learning. Keywords: Mathematical Reasoning, Mathematical Curiosity, Autograph-Aided Make a Match Learning Share Link | Plain Format | Corresponding Author (Iyon Maryono)

896	Mathematics	ABS-10
Analysis of Mathematical Problem-Posing Ability Isrokatun, Cici Sri Haryani*, Nadya Izdamia Rahmi Universitas Pendidikan Indonesia Jalan Dr. Setiabudhi, No.229, Bandung, West Java, Indonesia *cicisriharyani[at]student.upi.edu Abstract Problem-posing is the ability of students to raise the problem. Problem-posing ability is important owned by students in mathematics. It is because integrative mathematics learning students need to do scientific activities. The scientific activities consist of observing, questioning, gathering information and communicating. By having problem-posing abilities, students are expected to be more motivated to overcome the problems raised themselves. The purpose of this research is to analyse problem posing ability in mathematics in third-grade students at the elementary school levels. The method used qualitative research using descriptive analysis. In this case, problem-posing ability in third-grade students in mathematic is still low. This was proven by tests conducted in two elementary schools in Sumedang and obtained 37.7 and 42.5 score. Moreover, based on the analysis of students answers, there are some difficulties experienced by students, namely unable to answer what they know, they cannot find the most important problems, they have not been able to overcome the initial problems, and make questions. The indicators in problem-posing are interrelated, that is looking for the most important problem by making questions. It is because students will make questions based on the important information which they have already known. Keywords: Analysis; Problem-Posing Ability; Mathematics Share Link | Plain Format | Corresponding Author (Cici Sri Haryani)

897	Mathematics	ABS-1038
Quantifying ENSO and IOD Impact to Hotspot in Indonesia Based on Heterogeneous Correlation Map M Dafri(1)*, S Nurdiati(1), A Sopaheluwakan(2) 1) Mathematics Department, Faculty of Mathematics and Natural Science, IPB University, Bogor 16680, Indonesia 2) Center of Research and Development, Agency for Meteorology Climatolgy and Geophysics, Jakarta 10720, Indonesia Abstract Land and forest fires in Indonesia have a long history. El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) also have a role on land and forest fires in Indonesia. There are several major land and forest fires in Indonesia such as in 2002, 2006, 2009, 2015, and 2019 were allegedly an impact of ENSO and IOD. This research aims to find out how much ENSO and IOD impact to land and forest fires in Indonesia. This research was used Sea Surface Temperature (SST) anomalies in Nino 3.4 region and IOD region as an indicator for ENSO and IOD, while hotspot was used as an indicator of land and forest fires in Indonesia. Heterogeneous Correlation Map (HCM) was used to describe the correlation of hotspots with ENSO variance and IOD variance on spatial patterns. The HCM obtained from Singular Value Decomposition (SVD) analysis to identify the variances. The result showed that anomalies SST in Nino 3.4 region has greater correlations with hotspot in Provinces South Kalimantan and East Kalimantan, than other regions in Indonesian. Anomalies SST in Eastern IOD and DMI has greater correlations with hotspot in Provinces Lampung, South Sumatra, Jambi, South Kalimantan and Central Kalimantan, than other regions in Indonesia, while Western IOD has the smaller correlations with hotspot. Temporal analysis showed that larger variance of hotspot in Indonesia mostly at the mid of the year, where is it as an impact from dry season in Indonesia. Keywords: ADipole Mode Index, Land and Forest Fires, Hetergenous Correllation Map, Nino 3.4 Index, Sea Surface Temperature, Singular Value Decomposition Share Link | Plain Format | Corresponding Author (Muhammad Dafri)

898	Mathematics	ABS-300
Powtoon in Understanding Ability of Mathematics Leili Sholihatunnisa, Asep Jihad and Hamdan Sugilar Department of Mathematics Education, UIN Sunan Gunung Djati Bandung Abstract The aim of this research for knowing the increase of students understanding ability by using Powtoon. This study uses quasi-experiment method with a tutorial model conducted on class VIII students one of junior high school in Bandung City. The instruments research test about understanding ability. Based on the results of research show that student who get Powtoon learning with n-gain score average (0,59) better than students who get conventional learning with n-gain score average (0,36). Thus learning with Powtoon can be used as an alternative to improve understanding ability students. Keywords: Powtoon, Understanding Ability of Mathematics Share Link | Plain Format | Corresponding Author (Leili Sholihatunnisa)

899	Mathematics	ABS-310
Microsoft Mathematics for Procedural Fluency Competence Nur Afianti, Juariah, Hamdan Sugilar, Alia Lestari Universitas Islam Negeri Sunan Gunung Djati Bandung Abstract The purpose of this research is for knowing the increase of students procedural fluency competence by using Microsoft Mathematics. This study uses a quasi-experiment method in one of the VIII grade students of junior high school in Bandung City. The instruments research test is about procedural fluency competence. The results showed that students who get Microsoft Mathematics learning with the average value of gain score (0,53) is better than students who get conventional learning with the average value of gain score (0,46). Therefore it can be concluded that learning with Microsoft Mathematics can be used as an alternative to improve procedural fluency competence. Keywords: Microsoft Mathematics, Procedural Fluency Competence Share Link | Plain Format | Corresponding Author (Nur Afianti)

900	Mathematics	ABS-312
Graspable Math for Understanding Ability of Mathematics Agna Ilma Taofik, Juariah, T. Tutut Widiastuti A., Rahayu Kariadinata Universitas Islam Negeri Sunan Gunung Djati Bandung Abstract The aim of this research is for knowing the increase of students understanding ability of mathematics by using Graspable Math. This study uses a quasi-experiment method in one of the VIII grade students of junior high school in Bandung City. The instruments research is understanding ability of mathematics test. The results showed that students who get Graspable Math learning with the average value of gain score (0,50) is better than students who get conventional learning with the average value of gain score (0,48). Thus it can be concluded that learning with Graspable Math can be used as an alternative to improve understanding ability of mathematics. Keywords: Mathematics Application, Graspable Math, and Understanding Ability of Mathematics Share Link | Plain Format | Corresponding Author (Agna Ilma Taofik)

Page 30 (data 871 to 900 of 1092) | Displayed ini 30 data/page
<< PREV 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 NEXT >>

Powered By Konfrenzi Ultimate 1.832L-Build5 © 2007-2025 All Rights Reserved