Jusami | Indonesian Journal of Materials Science
Not a member yet
859 research outputs found
Sort by
MAGNETIC FORCE MICROSCOPE IMAGE EVALUATION OF MAGNETIC IRON OXIDE FLOPPY DISC WITH VARIOUS LIFT HEIGHTS
Get PDFMagnetic Force Microscope Image Evaluation of Magnetic Iron Oxide Floppy Disc with Various Lift Heights. One of the advantages of Scanning Probe Microscopes (SPM) or better known as the Atomic Force Microscope (AFM) is its ability to "see" in detail at the level of atoms and molecules, so as to improve understanding of how a system works and leads to new discoveries in areas such as life science, materials science, electrochemistry, polymer science, biophysics, nanotechnology and biotechnology. To understand about the MFM mode, amplitude, phase and topographic image, a piece of a flop-py disk as references sample was used in various lift heights. In this paper presented the principles of AFM work and explain the necessary components of such equipment. The MFM images were taken in floating operation method at different heights namely 30, 40 and 60 nm between the surface sample and Co-Cr cantilever tip. Result showed the distance between the cantilever tip to the sample surface influenced the image quality. The best amplitude image could be taken in 60 nm distance
Growth of ZnS:Ag:Cu Thin Film Deposited on Glass Substrates using Thermal Evaporation Technique for Alpha-photovoltaic
Get PDFThis paper presents the research on the growth of ZnS:Ag:Cu thin film on a glass substrate as a radio-luminescent material. The SRIM/TRIM software is used to determine the optimum thickness based on an energy deposition depth of 5.485 MeV Am 241 alpha radiation source on ZnS:Ag:Cu material. To increase the adhesive strength of the coating, initially, the glass substrate is etched using a plasma glow discharged at 280°C for 15 minutes. Multiple coatings of ZnS:Ag:Cu were etched on the glass substrate; this was carried out using a thermal evaporation technique to achieve the optimal thickness (based on SRIM/TRIM simulation). The thin film thickness was observed using a scanning electron microscope (SEM). The optical properties of the un-etched, etched glass substrate and thin-film were characterized using UV-Vis spectrometer. Based on SRIM/TRIM simulation, the optimal thickness is 22 mm which can be achieved by coating three times. From optical properties of ZnS:Ag:Cu thin film and after being analysed using Taue plot method, it is found that the energy gap of ZnS:Ag:Cu thin film is 2.48 eV. It can be concluded that the addition of Ag and Cu doped decrease the energy gap of ZnS (3.66 eV)
Calculated Radioactivity Yields of Gallium-67 using Matlab Codes
Get PDFIn nuclear medicine, gallium-67 (67Ga) is potentially applied for imaging a certain type of tissue. In this investigation, 67Ga is theoretically studied in terms of its potential radioactivity yields at the end of various energetic proton bombardments. Nuclear cross-sections derived from the Talys Evaluated Nuclear Data Library (TENDL) 2017 were used as the input files, while a Matlab code was developed to perform the yield calculations of 67Zn(p,n)67Ga and 68Zn(p,2n)67Ga nuclear reactions to produce 67Ga. Two different targets – enriched 67Zn and natZn targets – were simulated in the calculations. The calculated yields suggested that a maximum of 27.37 MBq/µAh could be achieved when enriched 67Zn target was irradiated with 15-MeV protons, whereas 46.99 MBq/µAh could be generated following a 30 MeV proton bombardment of enriched 68Zn target. Various radioactive gallium impurities, i.e. 63,64,65,66,68,70Ga and stable 69Ga isotope were also expected to be generated mostly via (p,n) and (p,2n) reactions when natZn target was used in the 67Ga production. In contrast, radioactive 66Ga and 68Ga impurities were mainly produced following bombardment of enriched 67Zn and 68Zn targets. This study can be used as a reference for future 67Ga radionuclide production
PERFORMANCE STUDY OF LiBOB/LiTFSI ELECTROLYTE SALT IN THE ALL-SOLID-STATE LITHIUM-ION BATTERY
Get PDFPERFORMANCE STUDY OF LiBOB/LiTFSI ELECTROLYTE SALT IN THE ALL-SOLIDSTATE LITHIUM-ION BATTERY. Solid polymer electrolyte is developed mainly to provide safer lithiumion battery upon high temperature operation. In this research, we employ LiBOB and LiTFSI electrolyte salt in various concentration to replace commercially used LiPF6 salt. Solution cast method was performed to produce polymer electrolyte membrane. PVdF-HFP was chosen as polymer matrix due to high dielectric constant, and compatibility to wide array of electrode materials as well as electrolyte salts. Higher amount of electrolyte salts contributes to thicker membrane and hence higher current output of the lithium-ion battery half-cells. SEM, FT-IR spectroscopy, and cyclic voltammetry measurement was conducted to evaluate li-ion battery cell performance. Between the two electrolyte salts used in this experiment, LiTFSI salt exhibited better performance compared to LiBOB
CHEMICAL DEGRADATION OF NAFION MEMBRANES UNDER PEMFC AS INVESTIGATED BY DFT METHOD
Get PDFCHEMICAL DEGRADATION OF NAFION MEMBRANES UNDER PEMFC AS INVESTIGATED BY DFT METHOD. An exsitu method has been developed to performance of Nafion's membrane in PEMFC (Proton Electrolyt Membrane Fuel Cells), caused by the chemical degradation of ·OH and ∙H radicals. The change of the chemical structure occurring during the degradation were primarily calculated of the relative energy of reactions by DFT (Density Functional Theory) method approach in the Gaussian software. This study aims to determine whether DFT method with functional B3LYP, PBEPBE, and B3PW91 and base sets 6-311++G can be used in determining the relative energy of a reaction and knowing the difference in role between ·OH and ∙H in the degradation process of the main chain Nafion with the final group are -CF2H, -CF=CF2 and -COOH. The three functionalities applied showed that the ·OH radical has more role than the ∙H radical in the degradation process of the Nafion main chain. In the -CF2H group was shown the relative energy value of reaction 2 is lower than reaction 5, in the -CF=CF2 group was shown the relative energy value of reaction 8* is lower than reaction 11 and in the -COOH group the relative energ value of reaction 14 is lower than reaction 16. By knowing the relative energy of the Nafion main chain degradation reaction with a certain final group and the role of certain radical compounds in the degradation process, the DFT method with functional B3LYP, PBEPBE and B3PW91 and base sets 6-311++G can recommend various modifications of the Nafion as a fuel cell membrane, particularly in increasing of membrane performance
THE EFFECT OF MILLING TIME AND PERCENTAGE OF DISPERSING AGENT ON THE CHARACTERISTIC OF SOLVENT-BASED BLACK PAINT FROM CARBON BLACK PIGMENT
Get PDFTHE EFFECT OF MILLING TIME AND PERCENTAGE OF DISPERSING AGENT ON THE CHARACTERISTIC OF SOLVENT-BASED BLACK PAINT FROM CARBON BLACK PIGMEN. The need for black paint made from carbon black pigment increasing year by year especially in the automotive world. The production of black paint is performed by milling the resin, pigment, additive/dispersing agent, and solvent. In the manufacturing process, it takes a relatively long time with precise dispersing agent composition toward pigment to get the product with blackness/solid black according to the expected quality. This work aims to study the role of the milling time of carbon black fw 200 beads on a 3 liter ball mill and the percentage of dispersing agents on paint color quality, especially blackness. The variations in milling time were 36, 48, and 60 hours and the weight percentage of dispersing agent toward pigment were 80%, 100%, and 120%. The optimum results obtained are at the milling time of 48 hours and on the percentage of dispersing agent of 120% with the product characteristics fulfills the requirement namely: 10 μm of particle fineness, 111.5 krebs unit of viscosity, 36.97% of solid content, 0.9839 gr/cc of specific gravity with desirable solid black color
THE EFFECT OF RATIO OF GAS MIXTURE FOR MECHANICAL PROPERTIES AND CRYSTAL STRUCTURES ON 316L STAINLESS STEEL BIOMATERIAL USING DC SPUTTERING TECHNIQUE
No full text316L stainless steel is widely used as an orthopedic implant due to its high corrosion resistance and biocompatibility, but the weakness of these materials is low hardness and high wear. The surface must be modified to improve the material. For the purpose, a titanium nitride (TiN) thin film was deposited on the surface of SS 316L using DC sputtering technique. The sputtering process was carried out for various of a gas mixture of argon (Ar) and nitrogen (N2) such as 90 Ar: 10N2, 80 Ar: 20 N2, 70 Ar: N2, and 60 Ar: 40 N2, while the other parameters kept constant. The objective of the gas mixture variation is to find out the optimum condition of ratio Ar: N2 gas mixture with the highest hardness and lowest wear resistance. From experiment done it’s found that the highest hardness in order of 232.02 VHN, while before being coated the hardness is 133.61 VHN, or there is an increasing hardness by factor 1.73, while the wear resistance reduces from 11.6 × 10-8 mm2/kg to 1.17 × 10-8 mm2/kg or there is reducing in wear resistance by factor 9.9. The optimum conditions were achieved at Ar: N2 ratio = 70:30. From XRD analysis, it can be concluded that the crystal structure of TiN thin film is cubic with the peaks (111), (200), (202), (311) and (222). From cross-section microstructure analysis using Scanning Microscope Electron (SEM), it’s found the thickness of the thin film is 744 nm
ANALISIS STRUKTUR KRISTAL LAPISAN TIPIS BaZr0,2Ti0,8O3 YANG DITUMBUHKAN DENGAN METODE SOL GEL
Get PDFANALISIS STRUKTUR KRISTAL LAPISAN TIPIS BaZr0,2Ti0,8O3 YANG DITUMBUHKAN DENGAN METODE SOL GEL. Penumbuhan lapisan tipis BaZr0,2Ti0,8O3 menggunakan metode sol gel yang disiapkan dengan spin coater telah berhasil ditumbuhkan di atas substrat Si. Bariumasetat, zirconium isoproponol, titanium isopropoksid digunakan sebagai bahan pembuat BZT dan asam asetat serta etilen glicol digunakan sebagai pelarut. Ada tiga prinsip dasar pembentukan lapisan tipis menggunakan metode sol gel yaitu proses kimia (pembuatan larutan), penumbuhan lapisan menggunakan spin coater, dan proses termal (annealing). Variasi jumlah lapis dilakukan untuk mendapatkan lapisan yang diinginkan. Sedangkan kecepatan dan waktu putar, suhu annealing, waktu annealing dibuat sama yaitu 3000 rpm selama 30 detik dengan 800 oC selama 3 jam. Karakterisasi yang dilakukan meliputi uji menggunakan alat X-Ray Flurosence (XRF) untuk mengetahui komposisi lapisan tipis BZT dan X-Ray Diffraction (XRD) untuk mengetahui struktur kristal. Hasil karakterisasi menggunakan XRF menunjukkan bahwa unsur-unsur pembentuk BZT telah terdeposit di atas substrat Si. Makin banyak jumlah lapisan maka makin banyak unsur-unsur pembentuk BZT. Hasil karakterisasi menggunakan XRD menunjukkan kekristalan lapisan tipis BZT. Hal ini ditunjukkan dengan munculnya beberapa puncak yang teridentifikasi sebagai milik BZT setelah dicocokkan dengan ICDD database. Hal ini diperkuat dengan penghalusan menggunakan program General Stucture Analysis System (GSAS). Makin banyak jumlah lapis makin tinggi intensitas pada suatu orientasi bidang tertentu