Page 29 (data 841 to 870 of 1039) | 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 NEXT >>

841	Material Engineering	ABS-708
ANALYSIS OF DETERMINING DELIVERABILITY TEST AND TRANSIET PRESSURE IN PW-02 WELL OF ALPHA FIELDS Puri Wijayanti (a*), Lestari Said (b), Prakash Jet Singh (b) (a) Program Studi Teknik Perminyakan, FTKE, Universitas Trisakti, Jakarta Barat 11440, Indonesia *puri.wijayanti[at]trisakti.ac.id (b) Program Studi Teknik Perminyakan, FTKE, Universitas Trisakti, Jakarta Barat 11440, Indonesia Abstract Quantitative analysis of reservoir properties in a well is determined by transient pressure analysis. Transient pressure according to its type consists of Pressure Build up and Pressure Draw Down. this analysis provides an overview of the characteristics of a reservoir. This analysis includes the process of determining drainage area, shape, heterogeneity, porosity, average pressure, skin, permeability, and distance from a reservoir to boundary or flow discontinuities. This test is to determine the ability of gas production in the PW-02 Well, carried out by using the Modified Isochronal test method. This test aims to determine the productivity of a potential (Absolute Open flow). Transient pressure test on PW-02 Well using the Pressure Build up Test (Type Curve Pressure Derivative) method, it is found that the well model is Vertical well and the reservoir model is Two porosity PSS. While the boundary model obtained is Rectangle. Then, the data obtained in the form of positive skin is 1.46, the permeability is 62.5 mD and the reservoir pressure is 2529.32 psia. Based on the analysis obtained Absolute Open Flow Potential (AOFP) of 117406 mscf/D. While the deliverability test value obtained is 117413 mscf/D with a n value of 0.825. Keywords: AOFP, Pressure Build Up Test, Modified Isochronal Test, Well Testing, Derivative Pressure PermaLink | Plain Format | Corresponding Author (Puri Wijayanti)

842	Material Engineering	ABS-221
Comparison of Koma Material for Import and Local Product P H Tjahjanti1,*, A D Wicaksono1, A. Akbar1, A N F Ganda2 1 Department of Mechanical Engineering, Universitas Muhammadiyah Sidoarjo, Kampus 2 Jalan Raya Gelam nomer 250 Candi Sidoarjo, Jawa Timur, Indonesia 2 Department of Mechanical Engineering, State University of Surabaya, Indonesia *E-mail: prantasi[at]gmail.com prantasiharmi[at]umsida.ac.id Abstract Koma material is one part of a wire cutting machine that is in PT. X in Indonesia, which functions as a wire straightening device that will be processed or cut. This material is made from cast iron and is obtained from imports. Never tried to make local product. The aim of the research was to make Koma material from cast iron. The method used is to make Koma material such as imported products and then do hardness testing and observe the microstructure using optical microscope. The results are compared with Koma imported products. The results show that the coma material of imported products has a higher hardness than local products, because there are differences in chemical elements in the cast iron. Keywords: Koma material, import product, local product, hardness, microstructure PermaLink | Plain Format | Corresponding Author (Prantasi Harmi Tjahjanti)

843	Material Engineering	ABS-227
Electrochemical Performance of supercapacitor from the biomass of Manihot Esculenta Crantz Sherly Novia Sari, Gustan Pari, Slamet Priyono, Ilma Nuroniah, Ahmad Sohib, Wahyu Bambang Widayatno, Achmad Subhan and Bambang Prihandoko Research Center of Physics, Indonesian Institute of Indonesia Abstract Low cost and very simple activation method (KOH as activating agent) is used for the synthesis of activated carbon derived from the biomass manihot esculenta crantz (mocaf). The mocaf derived activated carbon as electrode material in supercapacitor and characterized by SEM for to analyse the morphology, Brunauer-Emmet-Teller to know the surface area and to measure the electrochemical performance characterized by Cyclic voltammetry, Galvanostatic charge-discharge and Electrochemical impendance spectroscopy. Electrochemical studies indicate that the mocaf delivers the maximum specific capacitance of (36 F/g) at scan rate (5 mV/s) in aqueous electrolyte (1 M LiPF6) for (2.0 V) operating voltage. The electrodes from mocaf exhibits good rate capability with an excellent charging/ discharging cycle stability in aqueous electrolyte (1 M LiPF6) during 10.000 cycles. The results indicate that mocaf shows good electrochemical properties to be used for energy storage application. Keywords: mocaf, supercapacitor, energy storage, biomass, low cost PermaLink | Plain Format | Corresponding Author (Sherly Novia Sari)

844	Material Engineering	ABS-999
EVALUATION OF DRILLING HYDRAULIC CALCULATION TO THE ABILITY OFBOTTOM HOLE CLEANING HarinWidiyatni, ApriyandiRizkina, WaraqonitaImaningtyasDirastri Petroleum Engineering, Faculty of Earh Technology and Energy, UniversitasTrisakti, Jakarta Abstract In drilling operation there are two important matters that must be considered, which are the pumps and drillingfluid rheologythat are influencing hydraulics drilling system.The major function of drilling fluid is to lift the drill cutting to the surface and still maintain the drilling hole to avoid an encounter.Evaluation of hydraulics drilling for bottom hole cleaningwill count theparameter successwhich influence in removal of cutting to the surface for bottom hole cleaning and optimization drilling calculation hydraulics. The velocity of drilling fluid in annular, the flow that is formed and the ability of bottom hole cleaning are highly influenced by specifications of mud pump as a resource power for mud to flowthat also will determine how the value of flow rate can be circulated.Mud rheology,PV, YP and MWwill influence the performance of mud to carry cutting on drilling operation. The success of the bottom hole cleaning of drilling wells evaluated based on the calculation of hydraulics drilling at every depth and inclination changes while also review the parameters of Cutting Transport Ratio (Ft), Cutting Concentration (Ca), Cutting Carrying Index (CCI), Particle Bed Index (PBI) andoptimizatio of hydraulics drilling system. Q optimum is very influential on the value of bit hydraulic horse power (BHHP) and surface horse power (HPS) that provide more optimized power to pump the mud withminimize the effect of pressure loss. Keywords: Bit hydraulic horse power, Surface Horse Power, Pressure Loss, Cutting Removal PermaLink | Plain Format | Corresponding Author (RINI SETIATI)

845	Material Science	ABS-1026
Thermodynamics and Structural Properties of Copper Thin Film from Laser Ablation Riser Fahdiran Department of Physics, State University of Jakarta, Jakarta, Indonesia, 13220. Abstract We investigated the thermodynamics and structural change of Copper thin film irradiated by ultrafast high intensities laser. The film has dimension of 10 nm x 10 nm in lateral periodic condition and thickness 20 nm with free condition. The system is given such amount of laser energy above ablation threshold. The dynamics of the trajectories of atoms are followed using molecular dynamics simulation. At the beginning of the simulation, the system is compressive but followed by tensile pressure that break the system. Temperature and pressure properties indicated that the system are brought to non-equilibrium state. Structural analysis on the system as a function of time shows the phase change of the material, where at the end of simulation its already evaporated. Keywords: Copper, laser ablation, structure, thermodynamics PermaLink | Plain Format | Corresponding Author (Riser Fahdiran)

846	Material Science	ABS-517
Effect of Calicination Temperature on Structure and Surface Area of Kaolin/Zeolite LTA Composite Arif Rahman, Agung Purwanto Universitas Negeri Jakarta Abstract The synthesis of a composite series of Kaolin / Zeolite LTA were synthesized out through crystalline phase mixing and heating process at various temperatures. The composite syntesized were characterized by using SEM, XRD and FTIR, TGA and surface area analyzer. XRD analysis showed that crystal structure and amorphous phaseformed due to heating. The increasing of calcination temperature decreases LTA crystallinity significantly in line with increasing of temperature. Meanwhile FTIR spectroscopy provides information on changes in functional groups due to heating. TGA provides information on the amount of mass lost during heating due to the release of functional groups on LTA zeolite. Meanwhile N2 physisorption showed information on decreasing surface area due to increased temperature as a result of decreasing of pore volume due to heating. The calcination temperature of composites changes the composite pore structure Keywords: composite, Kaolin/Zeolite LTA PermaLink | Plain Format | Corresponding Author (Arif Rahman)

847	Material Science	ABS-263
The Effects of Substrate on Enhancement of UV Emission of ZnO nanorods Iwan Sugihartono(1), Amalia Dini Silmina(1), Riser Fahdiran(1), Isnaeni (2) (1)Program Studi Fisika, FMIPA Universitas Negeri Jakarta, Jl. Rawamangun Muka No. 01, Jakarta Timur 13220, Indonesia (2)Research Center for Physics, Indonesian Institute of Sciences, Banten 15314, Indonesia Abstract We have synthesized ZnO nanorods by hydrothermal at 95 oC for two hours on different substrates ie glass, ZnO and ITO. Morphologically, the average diameter of ZnO nanorods on glass, ZnO, ITO are 117.6 um, 133 um, 98.4 um, respectively. According to international centre for diffraction data (ICDD) number 01 079 0207, the ZnO nanorods on all substrates possess a polycrystalline wurtzite structure. Optically, ZnO nanorods on a glass substrate have strongest excitonic related ultraviolet (UV) emission. Its predicted, the ZnO seed layer deposited on glass substrate has optimum crystal structure and suppress defects related visible emission. Keywords: ZnO nanorods, different substrate, polycrystalline wurtzite, UV emission PermaLink | Plain Format | Corresponding Author (Iwan Sugihartono)

848	Material Science	ABS-8
A facile synthesis of zirconium-doped lithium titanate (Li4Ti5O12) via solid state reactions for lithium ion battery applications Ahmad Sohib (*), Slamet Priyono, Ilma Nuroniah, Achmad Subhan, Sherly Novia Sari, Wahyu Bambang Widayatno, and Bambang Prihandoko Research Centre for Physics, Indonesian Institute of Sciences Kawasan Puspiptek Serpong Gd. 442 Tangerang Selatan, Banten 15314, Indonesia *) asohib[at]outlook.com Abstract Lithium titanate is one of potential materials applied as anode material for energy storage device. The material however has poor electrical conductivity and inferior diffusion property. This study is aimed to synthesize LTO doped zirconium at titanium site to its properties and performance. In this work, a facile solid state reaction is employed to prepare Li4Ti5-xO12Zrx (x=0, 0.025, 0.05, and 0.075). Starting materials were stoichiometrically calculated and mixed by utilizing mortar for an hour than followed by calcination at 800oC for three hours. The XRD pattern reveals that lithium titanate was observed while some impurities such as rutile-TiO2 and zircon silicate still appear in all samples. The cell with LTOZr 0.05 provides the highest conductivity value of the assembled cells, 0.15 mS/cm. The CD test confirm that the highest capacity of the cells, 135.0 mAh/g, is achieved by the cell based LTOZr 0.05. In addition, CV measurement also exhibits that the current peak of the cells become sharper and the polarization degree become shorter as increasing amount of zirconium. Keywords: lithium titanate; zirconium; Lithium ion battery PermaLink | Plain Format | Corresponding Author (Ahmad Sohib)

849	Material Science	ABS-784
Synthesis of NaX Zeolite Using Elephant Grass (Pennisetum purpureum) as a Silica Source and Its Characterization Soni Setiadji[1,*], Citra Deliana Dewi Sundari[2], Ira Noviyanti[1] and Atthar Luqman Ivansyah[3] [1]Department of Chemistry, Faculty of Science and Technology, UIN Sunan Gunung Djati Bandung, Jl. A.H. Nasution No.105 Bandung, West Java, 40614, Indonesia. [2]Department of Chemistry Education, UIN Sunan Gunung Djati Bandung, Jl. Cimincrang, Cimenerang, Panyileukan, Bandung, West Java, 40292, Indonesia. [3]Master Program in Computational Science, Faculty of Mathematic and Natural Science, Institut Teknologi Bandung, Jl.Ganesha No. 10, Bandung, West Java, 40132, Indonesia Abstract NaX zeolite is a synthetic zeolites with faujasite framework that has large pores, which it is largely used as adsorbents. NaX zeolite was synthesized using silica which was extracted from elephant grass. The silica was isolated from elephant grass using its ash with conventional ignition method, with NaOH as solvent. The extracted silica purity is 86,33%. NaX zeolite was synthesized with 3.5 Na2O : Al2O3 : 2.9 SiO2 : 150 H2O as molar ratio in hydrothermal condition at 90 °C for 15 hours. Synthesized zeolite were then characterized using FT-IR to confirm the formation of zeolite based on chemical bonding that appears on the spectrum, XRD to confirm the framework structure of the formed zeolite, and SEM to obtain its morphology. Based on those analysis, it is known that the result of synthesis process is zeolite with NaX crystal structure and octahedral morphology with crystal sizes range 1-5 µm. Keywords: silica extraction, elephant grass, zeolite synthesis, NaX zeolite, hydrothermal method PermaLink | Plain Format | Corresponding Author (Soni Setiadji)

850	Material Science	ABS-537
Influence of Layer Thickness and 3D Printing Direction on Tensile Properties of Acrylonitrile Butadiene Styrene (ABS) Siska Titik Dwiyati, Ahmad Kholil, Septian Eka Putra, Riyadi Pendidikan Teknik Mesin, Universitas Negeri Jakarta Abstract The purpose of this research was to study tensile properties of 3D printing ABS material with axial and lateral direction. The specimen was printed according to ASTM D 632-02 by layer thickess variations around 0.1 mm, 0.2 mm and 0.3 mm. Moreover, three specimens was made for each printing direction. Tensile test was performed using Zwick Roell Series Z 021 machine. Then, the fracture surface was studied with scanning electron microscope (SEM). Based on the research from 6 variations layer of 3D printing, the optimal result was found on the axial direction of 0,3 mm thickness layer with tensile strength 30,6 MPa and ultimate tensile strength 550,81 N. The voids were seen at the fracture surface. Keywords: 3D printing, tensile properties PermaLink | Plain Format | Corresponding Author (Siska Titik Dwiyati)

851	Material Science	ABS-286
Laser Induced Melting of Gold Thin Film : A Molecular Dynamics Study Riser Fahdiran Department of Physics, State University of Jakarta Abstract We employed molecular dynamics simulation to explore the melting dynamics of Gold thin film due to ultrashort high-intensities laser irradiation. The film has dimension of 10 nm x 10 nm in lateral periodic condition and thickness 10 nm with free condition. The system is suppressed by the laser energy slightly above melting threshold and simulated under homogeneous and instantaneous energization. Within several ps the system already melt and the evolution are followed based on trajectory of each atom dynamics. During the expansion of the film, we also performed the local structure change based on Common Neighbor Analysis (CNA) method. Structure factor analysis indicated that the film is melted completely at the end of simulation, t = 20 ps. Keywords: Melting; Thin Film; Gold; Molecular Dynamics PermaLink | Plain Format | Corresponding Author (Riser Fahdiran)

852	Material Science	ABS-817
EFFECT OF reduced GRAPHENE OXIDE (rGO) INTO DYE SENSITIZED SOLAR CELL (DSSc) PERFORMANCE Muhamad Saepudin wahab (a*), Akhmad Herman Yuwono (b),Alfian Ferdiansyah (b) Metallurgy and Material, Indonesia University Abstract Dye plays a very important role in the Dye Sensitized Solar Cell (DSSC) application because the sunlight that comes in is captured and absorbed by dye. More light absorbed, the higher value of efficiency obtained. Therefore, dye plays a very vital role to increasing this efficiency value. For increasing the absorption of dye, this topic studied about effect of reduced graphene oxide (rGO) to DSSC Performance. its obtained through the hummers modified method which will be combined with dye in the ratio of wt% rGO-dye 0,1: 1; 0,3: 1; and 0,5: 1 respectively. Thickness Variation of rGO on the ITO transparent glass to enhance efficiency of DSSC also studied. The result show power conversion efficiency of the DSSC with the rGO-dye 0,1:1 (0,008%), rGO-dye 0,3:1 (0,019%), and rGO-dye 0,5:1 (0,0073%), which was higher than that of the DSSC without the rGO (0,0046%). ZnO nanorod as photoanode obtained by chemical bath deposition which is growth in temperatur 0 degree Celcius and Platina (Pt) as the counter electrode. SEM, UV-Vis and XRD were used to characterization of rGO and ZnO. Keywords: DSSC,reduced graphene oxide, ZnO PermaLink | Plain Format | Corresponding Author (Muhamad Saepudin Wahab)

853	Material Science	ABS-1115
The effect of Cobalt doping on The Photocatalytic Activity of Nanocomposites of ZnO Nanorods/Au Nanoparticles Anita Eka Putri(a), Liszulfah Roza(b), Vivi Fauzia(a*) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia *vivi[at]sci.ui.ac.id b) Departement ofPhysicsEducation, Universitas Muhammadiyah Prof. Dr. Hamka, Jakarta Timur 12130, Indonesia Abstract The photocatalytic performance of Zinc oxide nanorods (ZnO NRs) still needs to be improved. One method that could be used to enhance the photocatalytic activity of ZnO NRs is by adding the noble metals nanoparticles and transition metals dopings. In this work,we synthesized nanocomposites of ZnO NRs/Au and Co-doped ZnO NRs/Au nanoparticles (NPs) by using ultrasonic spray pyrolysis and hydrothermal methods on the glass substrate. The microstructural, morphological, and optical properties of both nanocomposites were characterized by using XRD, FESEM and UV-Vis and PL spectroscopy. The photocatalytic performance was evaluated through the degradation of methylene blue (MB) under UV radiation. The results show that the pure ZnO NRs only degrades 28.8%, while the ZnO NRs/Au NPs could degrades 37.3%. Furthermore, the Co doped ZnO NRs/Au NPs also increases the degradation rate up to 46.5%. Based on these results, we conclude that the presence of Au on ZnO NR’s surface could enhance the photocatalytic activity due to its role as an electron sink that reduces the recombination rate of electrons and holes while the incorporation of Co in ZnO NRs could also enhance the number of crystal defects that beneficial for enhancing the photocatalytic activity of ZnO NRs. Keywords: ZnO NRs/AuNPs nanocomposite; Co-doped; electron sink; photocatalytic activity; recombination PermaLink | Plain Format | Corresponding Author (Anita Eka Putri)

854	Material Science	ABS-866
Modification of the Maxwell Model for Calculation of Stress Relaxation and Creep Behavior for Polyester Yarns Mustamina Maulani (a), Cahaya Rosyidan (a*),Lisa Samura (a),Valentinus Galih Vidia Putra (b) a) Petroleum Engineering Department, Trisakti University, Jalan Kyai Tapa no 1, Jakarta 11440, Indonesia *cahayarosyidan[at]trisakti.ac.id b) Sekolah Tinggi Teknologi Tekstil Bandung, Jalan Jakarta no.31, Bandung , 40272, Indonesia Abstract Textile materials, especially yarns formed from polymers such as polyester during deformation, have viscoelastic properties, namely a combination of elastic and viscous properties. Several studies have been conducted to model viscoelastic on textile materials, especially yarns. In this study, modeling is done by fitting data through experiments which are then modeled with a theory of the modification of the Maxwell model as a reference in making predictions through the data fitting method. The results of the data fitting prediction in the form of exponential curves have a regression value that approaches the experimental curve (R^2 = 0.999 and 0.999). Keywords: Viscoelastic ; data fitting ; Maxwell Model PermaLink | Plain Format | Corresponding Author (LISA SAMURA)

855	Material Science	ABS-636
Influence of SiO2 and Ni as catalyst in MgH2 prepared by mechanical alloying technique Zulkarnain Jalil ,Malahayati, Ismail, Mursal, Erfan Handoko 1Department of Physics, Syiah Kuala University, Banda Aceh 23111, Indonesia 2Department of Mechanical Engineering, Syiah Kuala University, Banda Aceh 23111, Indonesia 3Department of Physics, Jakarta State University, Jakarta, Indonesia Abstract 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 oxide catalysts were used to reduce the operational temperature of MgH2. The silicon oxide used in this study was extracted from rice husks ash. The composition of MgH2 + 10wt% SiO2 + 5wt% Ni was prepared by mechanical alloying technique, by varying milling time 1, 5, 10 and 15 hours. XRD results indicate a decrease in particle size with longer milling time. MgH2 was obtained as the main phase followed by Ni and SiO2. SEM results showed that the longer milling time, the more particle size is homogeneous. Furthermore, thermal investigation using DSC showed that the desorption temperature obtained was in the range of values of 331,8 0C to 342,3 0C. The addition of 10wt% SiO2 and 5wt% Ni have improved sorption temperature and kinetic of MgH2. Keywords: Magnesium, hydrogen storage, mechanical alloying, catalyst, desorption PermaLink | Plain Format | Corresponding Author (Zulkarnain Jalil)

856	Material Science	ABS-125
Influence of Soaking Time on Tensile Strength of Coconut Fiber Muhammad Arsyad(a*), Rudy Soenoko (b), Arman(a), Nur Wahyuni(a) a) Mechanical Engineering Department, Politeknik Negeri Ujung Pandang, Jalan Perintis Kemerdekaan KM.10 Tamalanrea, Makassar 90245, Indonesia b) Mechanical Engineering Department, Univeristas Brawijaya, Jalan M.T. Haryono No.167 Malang 65145, Indonesia * arsyadhabe[at]poliupg.ac.id Abstract The objectives of research is to determine the effect of long soaking of coconut fiber in alkaline solution to the tensile strength of coconut fiber. The testing stages include preparation, soaking, drying, testing, and analysis. The materials used consist of coconut fiber, alkali solution, aquades, tensile test equipment, and furnace. Coconut fiber is soaked in an alkali solution with a concentration of 20% for 1, 5, 7, 9, and 11 hours. Then, the coconut fiber was rinsed with aquades before being dried in a furnace at 90oC for 5 hours. Furthermore, tests of mechanical properties include a single fiber tensile of coconut fiber with ASTM. Based on the results and discussion, it can be concluded that (a) the alkali treatment decreases the amount of hemicellulose and cellulose in coconut fiber, (b) the maximum tensile strength obtained at 7 hour treatment is 223.907 N/mm2. Keywords: soaking; alkali; tensile; coir PermaLink | Plain Format | Corresponding Author (Muhammad Arsyad)

857	Material Science	ABS-638
Desorption properties of mechanically milled MgH2-Ni catalyzed 10 wt% SiC for hydrogen storage materials application Zulkarnain Jalil1,*, Adi Rahwanto1, Akhyar2, Erfan Handoko3 1Department of Physics, Syiah Kuala University, Banda Aceh 23111, Indonesia 2Department of Mechanical Engineering, Syiah Kuala University, Banda Aceh 23111, Indonesia 3Department of Physics, Jakarta State University, Jakarta, Indonesia Abstract The objective of this study is to improve the hydrogen desorption temperature and the hydrogen desorption capacity. The material preparation was done through mechanical alloying technique. In this method, the milling of the material was carried out within 5 hours, 10 hours and 15 hours, ball to powder ratio was 10:1. The catalyst was inserted by 10 wt%SiC. From XRD measurements revealed that the sample was successfully reduced to a nanocrystalline scale. The phase MgH2 as the main phase, and followed by Ni and SiC phase as the minor phase. The microscopy observation with SEM showed the irregular particle shape, the particle size in the sample is not homogeneous because of the agglomeration effect during milling. The hydrogen release capacity was obtained in the samples which were milled for 10 hours at the weight of 5 wt% Ni-SiC catalyst with release of 2.6 wt% within 16 minutes. Keywords: Magnesium, hydrogen storage, mechanical alloying, catalyst, desorption PermaLink | Plain Format | Corresponding Author (Zulkarnain Jalil)

858	Material Science	ABS-129
Effect of Trivalent Manganese Substitution in a-Al2O3 Crystal on the Multiplet Energy Levels Based on First-Principles Calculations Mega Novita (a*), Duwi Nuvitalia (b), Nur Cholifah (c), Kazuyoshi Ogasawara (d) a) Faculty of Engineering and Informatics, Universitas PGRI Semarang, Jl. Sidodadi-Timur No.24 Semarang, Central Java 50232, Indonesia *novita[at]upgris.ac.id b) Faculty of Mathematics, Natural Science and Information Technology Eduation, Universitas PGRI Semarang, Jl. Sidodadi-Timur No.24 Semarang, Central Java 50232, Indonesia c) Lembaga Penelitian dan Pengabdian Kepada Masyarakat, Universitas PGRI Semarang, Jl. Lontar No.1 Semarang, Central Java 50232, Indonesia d) School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen Sanda, Hyogo 669-1337 Japan Abstract We performed an investigation on \(\alpha\)-Al\(_{2}\)O\(_{3}\): Mn\(^{3+}\) material based on first-principles calculations without referring to any experimental parameter for the first time. In order to estimate the lattice relaxation effect due to Mn\(^{3+}\) substitution, we carried out a geometry optimization using Cambridge Serial Total Energy Package (CASTEP) code. Next, the molecular orbitals (MO) were calculated using the discrete variational-X\(\alpha\) (DV-X\(\alpha\)) method while the multiplet energies were calculated discrete variational multi-electron (DVME) method. Since, the multiplet energies are generally overestimated, here we also used the energy corrections to improve the accuracy. We thus compared our calculated results with the observed data reported by McClure et. al., (1962). The results shows that by considering both of the lattice relaxation effect and the energy corrections, the agreement between our calculated results and the observed data is improved. Keywords: Mn3+, a-Al2O3, first-principles, DV-Xa, DVME PermaLink | Plain Format | Corresponding Author (Mega Novita)

859	Material Science	ABS-131
Pressure Dependence on Ruby Bond Length Based on First-Principles Band-Structure Calculations Mega Novita (a*), Nur Cholifah (b), Kazuyoshi Ogasawara (c) a) Faculty of Engineering and Informatics, Universitas PGRI Semarang, Jl. Sidodadi-Timur No.24 Semarang, Central Java 50232, Indonesia *novita[at]upgris.ac.id b) Lembaga Penelitian dan Pengabdian Kepada Masyarakat, Universitas PGRI Semarang, Jl. Lontar No.1 Semarang, Central Java 50232, Indonesia c) School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen Sanda, Hyogo 669-1337 Japan Abstract Ruby, or the trivalent chromium ion activated in alumina crystal (\(\alpha\)-Al\(_{2}\)O\(_{3}\): Cr\(^{3+}\)), needless to say, is a beautiful gemstone and known as the first solid-state laser in history. The so-called "ruby pressure scale" using its fluorescence lines is particularly popular in high-pressure science because of the simplicity and the accuracy of optical measurements in the diamond-anvil cell (DAC) experiments. Therefore, here performed first-principles band-structure calculations on the effect of external pressure on ruby bond length without referring to any experimental parameter. Cambridge Serial Total Energy Package (CASTEP) code was utilized to estimate the lattice relaxation effect as the external pressure applied which results in the ruby bond length. Firstly, we carried out the structural optimization of the pure \(\alpha\)-Al\(_{2}\)O\(_{3}\) crystal and then followed by the geometry optimization of \(\alpha\)-Al\(_{2}\)O\(_{3}\): Cr\(^{3+}\). The results show that Al-O bond lengths of the pure \(\alpha\)-Al\(_{2}\)O\(_{3}\) crystal and Cr-O bond lengths of \(\alpha\)-Al\(_{2}\)O\(_{3}\): Cr\(^{3+}\) decreased as the applied pressure increased. Keywords: pressure, first-principles, CASTEP, a-Al2O3 PermaLink | Plain Format | Corresponding Author (Mega Novita)

860	Material Science	ABS-912
TEMPERATURE AND ADDITIVE COCONUT SHELL CHARCOAL EFFECT ON DENSITY AND POROSITY OF CERAMIC MEMBRANE BASED ON ZEOLITE AND CLAY Agus Setyo Budi (a*), Mujadi (b), Esmar Budi (a) aDepartment of Physics, Universitas Negeri Jakarta Jl. Pemuda 10, Rawamangaun, Jakarta 13220, Indonesia bDepartment of Physics Education, Universitas Negeri Jakarta Jl. Pemuda 10, Rawamangaun, Jakarta 13220, Indonesia Abstract The aim of this research to investigate the influence of temperature and additive effect of coconut shell charcoal on the density and porosity of ceramic membranes based on zeolite and soil. With the addition of additives in the form of charcoal can reduce the density of ceramic membranes. It can also increase porosity of ceramics and clay based zeolite membranes. The results of the study show that based on the results of the Scanning Electron Microscopy (SEM), it can be seen that the largest pore size is owned by samples containing 80% zeolite and 10% additional. The number of pores produced depends on how much additive content is contained in the sample. The conclusion is that there is a tendency for the temperature to rise and the more additives contained in the sample, the more pores produced. Keywords: Temperature; additive coconut shell charcoal; density; porosity. PermaLink | Plain Format | Corresponding Author (Agus Setyo Budi)

861	Material Science	ABS-935
Indigenous Phosphate Solubilizing Bacteria from Waste Maja Fruit to Enhance Germination Rice Seed Susilawati(a), Sri Rahayu(a), Purwaningsih(b), Endang Noerhartati(c*) Universitas Wijaya Kusuma Surabaya Abstract Rhizosphere microorganisms such as phosphate solubilizing bacteria have been widely reported as bacteria that have the ability as phosphate solvents and promote growth. The purpose of this research was to isolate the indigenous bacteria from waste Maja fruit and evaluate whether these could enhance the viability of deteriorating rice seeds. The method used in the first stage of isolation, and evaluation of germination of rice seeds using a completely randomized design. It was revealed that three isolates are isolate 1-1, isolat1-2, and isolate 1-4 were able to solubilise phosphate and produce indole. The Result showed that the three isolates were able to increase the persentage of germination by up to 39,33%, the uniformity of germination by up to 40,76% and germination rate by up 10,46%/d. Keywords: Phosphate solubilizng bacteria; Waste maja fruit; Viability; Rice seeds PermaLink | Plain Format | Corresponding Author (Susilawati -)

862	Material Science	ABS-682
Morphology and Impedance characteristics of the nanostructured polyaniline films synthesised with different electrodeposition potentials Setia Budi, Raka deswara, Amir Mahmud, Yusmaniar Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Jakarta Timur 13220, Indonesia Abstract Nanostructured films of polyaniline were successfully synthesised using electrodeposition technique on stainless substrates. Fourier transform infrared spectroscopy, and X-ray diffraction investigation indicated that the electrodeposited polyaniline was an emeraldine phase. The influence of electrodeposition potentials on morphology, Brumauer-Emmet-Teller surface area and impedance values of the films were determined based on a scanning electron microscope, surface area analyser, and electrochemical impedance spectroscopy measurements, respectively. The films were composed by nanofiber polyaniline with diameter range from 10 to 60 nm. An increase of electrodeposition potential reduced the polyaniline diameter that produced high surface area films which resulted in high specific capacitance and low impedance values. This work shows the role of electropolymerization potential in controlling the necessary properties of the electrodeposited polyaniline films. Keywords: nanostrcutured film, polyanilin, electrodeposition potential, BET surface area, impedance PermaLink | Plain Format | Corresponding Author (Setia Budi)

863	Material Science	ABS-939
The I-V characteristcs of hydrothermal growth zno nanorods Agus Setyo Budi, Ishak Yulia Sari, Ratno Nuryadi, Fauzi Bakri, Dewi Muliyati Physics Department, Universitas Negeri Jakarta Abstract In this research, we analyze the conductivity properties of ZnO nanorods was grown by using a hydrothermal method. We use the I-V characteristics test to determine the conductivity properties. We apply voltage in the range of 1–30 volt. The result from the I-V characteristics shows that the greater value of the applied voltage produces a decrease of the resistance value. The resistance value obtained at a given voltage of 1 volt is 7.8 kOhm, while at a voltages of 30 volts is 0.5 kOhm. The I-V curve profile indicates that interface between ZnO nanorods and Au-electrode shows a Schottky barrier characteristics. Keywords: zno nanorods, i-v characteristics, hydrothermal nanorods PermaLink | Plain Format | Corresponding Author (Agus Setyo Budi)

864	Material Science	ABS-945
Characteristic Fillet of Aloe Vera Gel as Edible Coating Luh Suriati, I Made Suparta Utama Warmadewa University Abstract Abstract: Edible coating is biodegradable and eco-friendly packaging that current developments. Constituent components of edible coatings in the form of hydrocolloid (polysaccharides, proteins), lipids and composite. The edible coating serves as a protective material which is packed from outside influences also functions as a matrix of antimicrobial agents. Synthetic preservatives that many outstanding raises concerns of the community to use it, because of the high risk on health. One of the potential natural ingredients as an edible coating and also as a natural preservative is Aloe Vera gel. Aloe Vera is a polysaccharide that contains many components of bioactive, but the disadvantage easily becomes diluted. Aloe Vera gel should be kept on the proper environmental conditions. This research aims to know the influence of storage temperatures against characteristics of fillet Aloe Vera that potential as an edible coating. This study used a randomized complete design. Color fillet Aloe Vera clear white initially when stored at room temperature turns pink on day 2. While stored at cold temperatures the color change on day 4. The gel is stored at cool temperatures have pH and moisture content are relatively stable, decreased severity is also lower compared to store at room temperature Keywords: Keywords: keyword 1; Edible coating 2; gel 3; Aloe vera 4; fillet 5; biodegradeable PermaLink | Plain Format | Corresponding Author (Luh Suriati)

865	Material Science	ABS-695
The electrical characteristics, structure, and morphology of local mineral-based nanocomposites ceramic as an alcohol sensor Hasniah Aliah (a*), Ryan Nur Iman (a), Asti Sawitri (a), Dani Gustaman Syarif (b), Andhy Setiawan (c), Wahyudin Darmalaksana (d), Adam Malik (e) a) Department of Physics, UIN Sunan Gunung Djati Bandung, Jl. A H Nasution 105, Bandung 40614, Indonesia *hasniahaliah[at]uinsgd.ac.id b) Center for Applied Nuclear Science and Technology, BATAN, Jl. Taman Sari 71 Bandung 40132, Indonesia c) Department of Physics Education, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi 229 Bandung 40154, Indonesia d)Center of Research, UIN Sunan Gunung Djati, Jl. A.H. Nasution 105 Bandung 40164, Indonesia e) Department of Physics Education, UIN Sunan Gunung Djati Bandung, Jl. A.H. Nasution 105 Bandung 40164, Indonesia Abstract This report has been written based on research aimed to know electrical characterize, structure, and morphology of ceramic nanocomposites. Materials are used to consist of Indonesia local minerals are jarosite and manganite minerals as sources oxide iron, mangan, and oxide zinc is from commercial. The third materials were mixed by using precipitation method whereas the ceramic nanocomposite was fabricated by using a screen printing method and fired at 600 °C temperature with a furnace. Sample structure and morphology had been examined by using XRD and SEM respectively. The result of the characterization indicated that a sample was fabricated measured nanometer scale with three phases on diffraction peaks and had hexagonal-spinel structures. The sample also had high porosity. The electrical charracteristic of the sample was examined with an electrical tester had to function R-T in ambient and alcohol environments. Resistance value had been known in ambient and alcohol environments were different. The difference in resistance value indicated that a sample had a very different response in both of the environments. Nanometre size and high porosity of the sample were very supported to be processed gas adsorption. So, a sample had a high level of response. Therefore, nanocomposite ceramic had been fabricated potentially for application in the sensor field, especially as an alcohol gas sensor. Keywords: Nanocomposite, Jarosite, Manganite, Spinel, Alcohol gas sensor PermaLink | Plain Format | Corresponding Author (Hasniah Aliah)

866	Material Science	ABS-472
Effect of Low Nickel Substitution on Structure, Morphology, and Electrical Transport of La0.7Sr0.2Ba0.1Mn1-xNixO3 ( x = 0.02 and 0.05) Dicky Rezky Munazat(a), Budhy Kurniawan(a*), Agung Imaduddin(b) (a)Department of Physics, Universitas Indonesia, Depok 16424, Indonesia *budhy.kurniawan[at]sci.ui.ac.id (b)Research Center for Metallurgy and Materials, Indonesian Institute of Sciences (LIPI), Gedung 470, Puspiptek, South Tangerang 15314, Banten, Indonesia Abstract Polycrystalline La0.7Sr0.2Ba0.1Mn1-xNixO3 (x = 0.02 and 0.05) has been successfully synthesized by sol-gel method. This research aims to investigate the effects of low nickel substitution on the correlation between structure, microstructure, and electrical transport behavior. From Rietveld refinement result, crystal structure both samples were found to be Rhombohedral with R-3c (167) space group. Low nickel substitution at Mn-site shows that the Mn-O-Mn bond angle decreases and the Mn-O bond length increase which linked Jahn-Teller distortion, double exchange, core-shell model, and percolation model. Scanning electron microscope (SEM) result reveals that nickel substitution leads to smaller grain size. Temperature-dependent resistivity ρ(T) has been measured at 15-285 K with zero field cooling. The ρ(T) increases with decreasing grain size because of the enhancement of the grain boundary effect with the increase in the nickel content. The Curie temperature (TCMod) and the temperature of the metal-insulator transition (TM-I) moves to lower temperatures with increasing nickel substitution content. Percolation model can describe the electrical behavior of both samples based on electron-electron, electron-magnon, and electron-phonon scattering, and Kondo-like spin dependent scattering at low temperature and adiabatic small polaron hopping at high temperature. Keywords: Nickel Substitution, Mix Valance Manganite, Percolation Model, Resistivity PermaLink | Plain Format | Corresponding Author (Dicky Rezky Munazat)

867	Material Science	ABS-219
Fourier Transformed Infrared (FTIR) Spectroscopy for Analysis of Cholesteryl Acrylate Liquid Crystall-Indium Tin Oxide Composites Afrizal, Arif Rahman, Iwan Sugihartono, Friday Veronica Florencia, Linggar Jati Departmen Chemistry of Universitas Negeri Jakarta Abstract Research and development of liquid crystal of cholesteryl acrylate growing up now. The aim of this research is to synthesis composites and polymerizations of cholesteryl acrylate with dopan of indium tin oxide (ITO). The blending process of cholesterol acrylate and ITO was performed using casting solution technique at 75C for 30 minutes and at various the concentration of ITO. In this research using variation concentration of ITO and power of lamp for UV curing process. Monomer KA and ITO have succeeded in becoming a composite with photopolymerization process with UV curing method with variation of UV lamp power that is 10, 25, 40 and 55 watt. In functional group analysis with FTIR showed vibration of In-OH bond with C-O at wave number 1056,99 cm-1. FTIR showed a peak at wave number 2929,87 cm-1 for vibration of groups in bond C-H in vinyl, wave number at 2860,01 cm-1 for vibration bond of C-H alyfatic. Spectrum FTIR of ITO at wave number 437,84; 487,99; 534,28; 619,15 cm-1. Peak at 2100 cm-1 has dissepeared in spectrum FTIR of Cholesteryl acrylate which showed molecule of cholesteryl acrylate had polymerized. Conductivity of blending of Cholesteryl acrylate-ITO was determined using by LCR meter. In general conductivity value and permittivity of blended ChoA-ITO increase with the increasing of the concentration of dopan ITO was added to the composites. e value of PKA-ITO composite conductivity has a value greater than the value of KA-ITO conductivity of 4,0783x10-10 S/m. Keywords: Cholesteryl acrylate, composite, photopolymerization, UV curing, characteristic and conductivity PermaLink | Plain Format | Corresponding Author (Afrizal Afrizal)

868	Material Science	ABS-475
Structure, Microstructure, Electrical Transport Mechanism and Magnetoresistance in La0.8Ag0.2MnO3 Budhy Kurniawan(a*), Nabila Aishya Sahara(a), Agung Imadudin(b), Ikhwan Nur Rahman(a), Dicky Rezky Munazat(a) and Dhawud Sabilur Razaq(a) a) Departement of Physics, Faculty of Mathematics and natural Sciences, Universitas Indonesia, Depok 16424, Indonesia *budhy.kurniawan[at]sci.ui.ac.id b) Research center for Metallurgy and Materials, Indonesian Institute of Science (LIPI), Gedung 470, Puspitek, South Tangerang 15314, Banten, Indonesia Abstract Bulk polycrystalline sample of La0.8Ag0.2MnO3 has been successfully synthesized by the sol gel method. Structural, morphology, electrical properties and magnetoresistance has been investigated. Refinement results from XRD at room temperature showed a single phase material with a rhombohedral crystal structure and R-3c space group. Electrical transport showed by comparison of experimental data with theoretical model, the sample undergo a metal-insulator transition at TM-I accompanying the ferromagnetic-paramagnetic transition. Data for temperature dependence of resistivity has been fitted using the formula ρ(T)= ρ_FM f+ 〖(1-f)ρ〗_PM, ρFM is resistivity of the ferromagnetic region, ρPM is resistivity of the paramagnetic region and f is the volume fraction of ferromagnetic phase. Result of fitted data is in good agreement with experimental data. MR measurements in the range of magnetic field 0-1 T, measurements were carried out at temperatures of 15 K, 100 K, 200 K and 285 K, the results showed a decrease in resistivity. Keywords: electrical transport; magnetoresistance; percolation model PermaLink | Plain Format | Corresponding Author (Ikhwan Nur Rahman)

869	Material Science	ABS-482
Effect of Sintering Temperature on Structure and Morphology of Ca0.95La0.02Bi0.03MnO3 Perovskite Manganite Prepared by Sol-Gel Method Umar Faruq(a), Budhy Kurniawan (a*) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424, Indonesia *budhy.kurniawan[at]sci.ui.ac.id Abstract The effect of sintering temperature on the structure and morphology of Ca0.95La0.02Bi0.03MnO3 was investigated by X-ray diffraction and Scanning Electron Microscopy. The sample was prepared by sol-gel method. Their homogeneity was confirmed using X-ray diffraction. Rietveld refinement of X-Ray diffraction results showed that the sample sintered at 1100 C for 12 h are single phase and have an orthorhombic structure with Pnma space group. While the samples were sintered at 900 C and 1000 C did not show a single phase due to another peak is found. For the lattice parameter, crystal volume increases with increasing sintering temperature. The largest crystal volume was reached at sintering temperature 1100 C which is equal to 208.535 Å. For the angle of the Mn-O-Mn bond, the sample was sintered at 1000 C has the largest value obtained 152.778 (deg) while at 1100 C is 152.702 (deg) and 900 C is 151.652 (deg). For the average Mn-O bond length shows relatively the same value for all sintering temperature. Scanning Electron Microscopy was used to study the morphology of the materials, grain size increases with increasing sintering temperature. Keywords: CaMnO3, Sintering temperature, Sol-gel method, Lattice parameter PermaLink | Plain Format | Corresponding Author (Umar Faruq)

870	Material Science	ABS-483
Influence of Sintering Temperature on the Structure and Electrical Transport Properties of La0.7Ba0.1Sr0.2Mn0.85Cu0.15O3 Manganites Dhawud Sabilur Razaq(a), Budhy Kurniawan(a*), Agung Imaduddin(b) (a) Department of Physics, Universitas Indonesia, Depok 16424, Indonesia * budhy.kurniawan[at]sci.ui.ac.id (b) Research Center for Metallurgy and Materials, Indonesian Institute of Sciences (LIPI), Gedung 470, Puspiptek, South Tangerang 15314, Banten, Indonesia Abstract A systematic study of the La0.7Ba0.1Sr0.2Mn0.85Cu0.15O3 manganites have been conducted, mainly to understand the influence of sintering temperature on structure, microstructure, and electrical transport properties in the materials. Polycrystalline sample of La0.7Ba0.1Sr0.2Mn0.85Cu0.15O3 were prepared using sol-gel method and sintered at 1100 °C and 1200 °C. X-ray diffraction result shows that sintering temperature does not affect the crystal structure of the materials which remain rhombohedral with R-3c space group. a more detailed examination shows that sintering temperature change the unit cell volume, <Mn-O-Mn> bond length, and <Mn-O> bond angle of the samples. The electrical resistivity decreases followed by the decrease in the grain size with the increase in sintering temperature. Analysis using theoretical model shows that both samples can be well explained using percolation model. Fitting result suggests that the transport properties of the materials at low temperature were governed by the scattering and interaction between electron, phonon, and magnon. At high temperature, the electrical transport of the samples were governed by the hopping of polarons. Keywords: Structure; Electrical Transport; Sintering; Percolation Model; Manganites PermaLink | Plain Format | Corresponding Author (dhawud sabilur razaq)

Page 29 (data 841 to 870 of 1039) | 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 NEXT >>

Powered By Konfrenzi 1.832K-Build4 © 2025 All Rights Reserved