Indonesia Conference Directory

Corresponding Author
Muhammad Khairurrijal

Institutions
Deparment of Physics, Universitas Gadjah Mada, Indonesia
*m.khairurrijal[at]mail.ugm.ac.id

Abstract
Hydroxyapatite (HAp) made from crab shells on SS 316L was successfully coated using electrophoretic deposition (EPD) method. Variations used in the EPD process are electrical voltage (20 volts and 50 volts), deposition time (10 and 5 minutes), and speed of withdrawal (0.1 mm/s; 0.5 mm/s; 1 mm/s). These three combinations of variations are not yet used in this coating method before. The layer characteristics using SEM and XRD showed differences in shape of the morphology of the layers and the crystal structure for each variation of the experiment. At higher electrical voltages the morphology of the layer gets better with less agglomeration and the thickness of the layer increased. At high voltages, the shorter deposition time increased the quality of the crystal structure but reduced the thickness of the layer. Retraction speed affects the bond strength between layers and substrate. The higher the withdrawal speed, the stronger the kinetic energy that interferes with the binding layer. The best results in this study were obtained at 50 volts, with a withdrawal speed of 0.1 mm/s in 5 minutes. This result can be seen by the fairly evenly distributed HAp layer covering the substrate, sufficient layer density and high crystalline size and purity of the HAp layer.

Keywords
crab shells, EPD, HAp, bone implants, SS 316L

Topic
Biomaterials and applications

Link: https://ifory.id/abstract/VFgr3NCmeWa8

Corresponding Author
NARONG SANGWANATEE

Institutions
1Applied Physics Research Group, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand
2Department of Electronics, Faculty of Engineering, King Mongkut-s Institute of Technology Ladkrabang, Bangkok 10520, Thailand
3Electronics Technology, Faculty of Science, Ramkhamhaeng University, Huamark Bangkapi Bangkok Thailand. 10240

Abstract
In this study present the effect of Flash radiation to forward bias current-voltage (I-V) of PN diode by using Comsol simulation program. The results show surface thermal and electric change while expose by radiation with flash exposure technique. Series resistance (Rs) increase around 2 times and close to idea case after expose by radiation, the radiation will impact to bulk defect and reduce surface recombination. Radiation induce temperature on surface and deep into silicon bulk. The value of Rs increase with increase expose time. The changing of Rs becomes independent from radiation dose at high forward bias voltage.

Keywords
PN Diode ;Soft Radiation

Topic
Optical, luminescence, Electronic Materials and applications

Link: https://ifory.id/abstract/awjXz8qUCPMT

Corresponding Author
Jordan Al Khalil

Institutions
Faculty of Mathematics and Science, State University of Medan
Jalan Willem Iskandar, Pasar V, Medan Estate, Sumatera Utara, Indonesia

Abstract
Research on graphene has developed in recent years. This is due to its excellent physical, mechanical, thermal and optical properties. Graphene is a potential nanofilter that can improve composite properties according to its excellent structure. Graphene has wide potential applications because of its exceptional properties and large quantities with low cost. However, to obtain pure graphene is difficult. An alternative, we can make a derivative of graphite that approaches graphene, that is graphene oxide. Graphene oxide (GO) is very attractive because of its low cost, easy access, and extensive ability to be converted into graphene. In this research, we used Hummers method to obtain the graphene oxide. This method is a commonly used method because it is easy and inexpensive. To find out the characteristics and composition of graphene oxide, the XRD and SEM instruments were used. After the testing and analysis process, it can produce graphene oxide material which is in accordance with the standard for later use as nanocomposite materials and we can apply it in more variety of potential applications in current technology.

Keywords
Graphene, Graphene Oxide, Hummers Method

Topic
Nano-materials and applications

Link: https://ifory.id/abstract/8GjH7VCbUZJL

Corresponding Author
Mulyadi Muljadi

Institutions
Physics Department, MIPA UNiversity Sriwijaya Palembang

Reseach Center for Physics LIPI

Abstract
Alloy of NdFeB powder is used for manufacture of permanent magnet and it has highest magnetic properties compared to other permanent magnet materials such as : Ba-ferrite, AlNiCo and SmCo.The Flakes of NdFeB was made by melt spinn method and it has about 0.2 – 0.3 mm in thickness. The flakes of NdFeB was milled by using High Energy Milling (HEM) machine and used a liquid toluene as milling media. The milling time was varried such as : 30, 60, 90, and 120. After milling, the samples were dried by using Vacuum dryer at temperature 80oC under vacuum (10 mmbar) for 2 hours. The fine powder samples were analyzed crystall structure by using XRD, measured magnetic properties by using VSM and also measured particle size distribution (PSA). The characterization result show that the milling time gives a effect on the crystall structure and magnetic properties, where samples with milling time 60 dan 90 minutes has Fe phase as dominant phase and the Nd2Fe14B phase does not existing also the coercivity value tends to decrease until lower than 100 Oe. Samples with milling time about 30 and 60 minutes have Fe phase and Nd2Fe14B phase also they have corecivity value about 850 – 1040 Oe. The means of particle size is achieved about 1.44 µm at sample with milling time 60 minutes.

Keywords
Magnet Nd2Fe14B, Flakes NdFeB, HEM, coercivity

Topic
Metal alloys, ceramics and composite materials

Link: https://ifory.id/abstract/eKDFN4pdLVWx

Corresponding Author
NARONG SANGWANATEE

Institutions
Applied Physics, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand

Abstract
Nd3+ ion doped lithium aluminium phosphate glasses were synthesized and studied their properties for laser medium application. The density and the refractive index of the glass samples were carried out at the room temperature. The optical and luminescence properties were studied by investigating absorption and NIR emission spectra of the glass samples. The glasses absorbed photons in ultraviolet (UV), visible light (VIS) and near-infrared (NIR) regions are clearly observed from absorption spectra. For the photoluminescence properties, the glass samples showed the strongest emission at 1063 nm when it were excited by 581 nm which assigned to the energy transitions of Nd3+. The three phenomenological Judd-Ofelt parameters (Ω2, Ω4, Ω6) were determined from the spectral intensities of absorption band in order to calculate the radiative transition possibility (AR), stimulated emission cross section (σ(p)) and branching ratio (R) of the 4F3/2  4I9/2, 4I11/2 and 4I13/2 transitions. From the obtained results the conclusions made about the possibility of using these glasses as laser material.

Keywords
luminescence ,aluminium phosphate

Topic
Optical, luminescence, Electronic Materials and applications

Link: https://ifory.id/abstract/b2hf4vwGkgym

Corresponding Author
Adhi Satriyatama

Institutions
(a)Department of Chemical Engineering, Faculty of Industrial Technology, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung 40132, Indonesia
*a.satriyatama[at]gmail.com
(b)Department of Material Engineering, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung 40132, Indonesia
(c) Department of Mechanical Engineering, Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Jalan Ganesha 10 Bandung 40132, Indonesia

Abstract
SONAR (Sound Navigation and Ranging) has been widely applied civilian and military needs. In order to avoid detection of enemy active sonar, submarines are equipped with acoustic tile which functions to absorb signals from active sonar and reduce the noise caused by the submarine itself. Polyisobutylene which is an active ingredient of material acoustic tile currently has high toxicity to aquatic organisms and manufacturing costs are quite expensive. Polystyrene and graphite as doping material have potential to be applied as an acoustic waves absorbent. In this study, graphite and polystyrene were made as acoustic absorbent acoustic wave composite material. The research begins with the stage of optimizing the percentage of matrix, filler, and thinner with sound absorption intensity parameters at frequencies of 50 Hz-6000 Hz with matrix results: filler: thinner at 79%: 6% 15%. The composite was then characterized by SEM-EDX at a magnification of 150× to 5000 × and calculated the value of its density. Mechanical test is also done by a compressive test with an optimum composite of 60G/40PS of 0.65 MPa. Test for salinity resistance in a solution of 3.5%wt NaCl and 3.5% MgCl2 for 120 hours and obtain optimum results at 80G/20PS. Tests for the absorption of acoustic waves were tested in the frequency range 50 Hz-6300 Hz using an impedance tube with an optimum composition of 0G/100PS.

Keywords
Polystyrene, Graphite, Composite, Acoustic Tile

Topic
Metal alloys, ceramics and composite materials

Link: https://ifory.id/abstract/fFhYGuTLpywk

Corresponding Author
DOMINI LESTARI SINAGA

Institutions
(a) Department of Physics, State University Of Medan, Indonesia
Corresponding Author : topartam[at]gmail.com

Abstract
Reservoir temperature measurements have been carried out using the empirical geotermometer method at the Tinggi Raja Geothermal Simalungun district in order to determine the value of the Tinggi Raja geothermal reservoir temperature. The study was conducted using the Na-K geotermometer method, the Na-K-Ca-Mg geotermometer, a Na-K-Ca-Mg geotermometer to obtain the temperature value of the geothermal reservoir. The results of the study based on the empirical Geotermometer equation show the surface temperature of hot water and the average temperature of the reservoir. The average acceptable temperature of the reservoir is the average temperature calculated using a Na-K-Ca Geotermometer.

Keywords
Geotermometer, Geothermal, Geothermal Reservoir

Topic
Physics related sciences

Link: https://ifory.id/abstract/x27uhrqjKC3Y

Corresponding Author

Institutions
1Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan, 20221, Indonesia
2Department of Physics, Faculty of Mathematics and Natural Sciences, Padjajaran University

Abstract
The medium glass was made from chemical compounds with a composition (70-x) P2O5 - 10Bi2O3 - 10Na2O - 10Gd2O3 - xDy2O3 (where x = 0; 0.05; 0.1; 0, 5; 1.0; 3.0 (mol%)) which is doped by active ion xDy2O3. All of propofed chemical compounds are in the form of powder with a mass of 20 gram of mixture in an alumina crucible and prepared by melt-quenching method. The glass that has been obtained with a size (3x10x10) mm3 and smoothed to get a flat surface and high transparency. Optical properties of glass samples Dy:PBiNaGd determined by measuring by absorption spectrum and spectrophotometer at area visible with different consentration. Analysis indicate eleven inhomogeneous displacement bands at various positions and intensities with hypersensitive transitions at 1274 nm (6H15/2→6F11/2). Emission spectrum in medium glass Dy:PBiNaGd is supported using excitation wavelength (λeks) 350 nm and indicated that the highest intensity is in Dy:PBiNaGd4 where there four transition band emisin are namely 4H9/2 → 6H13/2 (483 nm), 4H9/2 → 6H11/2 nm), 4H9/2 → 6H9/2 (661 nm) and 4H9/2 → 6H6/2 (750 nm).

Keywords
Glass Phosphate, Disprosium, Photoluminescence

Topic
Optical, luminescence, Electronic Materials and applications

Link: https://ifory.id/abstract/yreC6uJhawgY

Corresponding Author
Iwan Sugihartono

Institutions
1Program Studi Fisika, FMIPA Universitas Negeri Jakarta, Jl. Rawamangun Muka, Rawamangun, Jakarta Timur, Indonesia 13220
2Program Studi Kimia, FMIPA Universitas Negeri Jakarta, Jl. Rawamangun Muka, Rawamangun, Jakarta Timur, Indonesia 13220

Abstract
We have grown no-doped and Al-doped ZnO thin films with different Al element composition by ultrasonic spray pyrolysis (USP). The deposition by USP was performed with the temperature of 450 oC, ultrasonic frequency of 1.7 MHz, and under atmosphere ambient for 15 minutes on top of Si substrate. No-doped and Al-doped ZnO thin films were confirmed structurally by x-ray diffraction (XRD). Optical measurement also performed in order to observe absorbance, transmittance, and reflectance properties. Photoluminescence properties show two typical ZnO emissions i.e. ultraviolet and visible. Then, the relevance of structural properties and optical properties will be used to analyze the effect of Al element as dopant on characteristic of electrochemical impedance of ZnO thin films.

Keywords
Al doped ZnO, XRD, Optical measurement, Phototoluminescence, Electrochemical impedance

Topic
Optical, luminescence, Electronic Materials and applications

Link: https://ifory.id/abstract/xKMXFJ8VPCaN

Corresponding Author
Rudy T.M. Situmeang

Institutions
1 Department of Chemistry, University of Lampung, Indonesia
2 Department of Physics, University of Lampung, Indonesia

Abstract
Lanthanum chromite is a material that plays a large role in the development of fuel cells, catalysts, electronic devices, semiconductors and magnetics. The application of this compound is determined by the material characteristics. The LaCr1-xVxO3 compound was prepared using a simultaneously method of sol-gel and freeze-drying from salts of chrome, lanthanum, and vanadium in pectin solution. The characterization results using X-ray diffraction, diffuse-reflectance UV-Vis spectrophotometer, and SEM-EDS showed that the materials formed have the main structure of ABO3 perovskite (such as LaCrO3 and LaVO3) with minor phases of LaCr2O6 and LaVO4 while the band-gap energy of materials due to the addition of vanadium in LaCrO3, it shifts its energy to a lower direction, namely: 2.89; 2.3; 2.4; 2.5 eV for LaCr1-xVxO3 (where x = 0, 0.1, 0.3, and 0.5), respectively. Then, SEM micrographs showed that the distribution of the crystalline phase is fairly even and homogeneous.

Keywords
Perovskite, nanomaterial, band-gap energy, well distribution

Topic
Nano-materials and applications

Link: https://ifory.id/abstract/8Gh9zZtw23Xm

Corresponding Author
Motlan Motlan

Institutions
1Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan
Email: motlan[at]unimed.ac.id

Abstract
ZnO thin film has been successfully synthesized by sol-gel spin coating method. The compounds used were zinc acetate, isopropanol, and diethanolamine. The ZnO thin film was grown a FTO glass substrate, and annealed at 500 degree celcius. The variation of the hold time is consecutively 30, 60, 90, 150 minutes. The XRD results show that the ZnO thin film crystal structure is wurtize hexagonal. The smallest crystal size is 22.3 nm when the hold time is 30 minutes. SEM results show the morphology of the thin films is a uniform round granules. The UN-Vis results show that the sharp increase in transmission is in the range of 350 to 400 nm wavelength.

Keywords
ZnO thin film, post annealing hold time, Sol-gel Spin Coating

Topic
Thin film and application

Link: https://ifory.id/abstract/mBTMQgXLDbUV

Corresponding Author
Jurubahasa Sinuraya

Institutions
Physics Department, Mathematics and Natural Sciences Faculty, Universitas Negeri Medan

Abstract
Creativity is one of the important elements in learning physics but is rarely studied to find out the effects of teaching applied to increasing creativity. The research is intended to describe the use of The ICARE Practice Based on Worksheet in increasing student creativity in the Physics Education Study Program. The course assessment formally uses The ICARE Practice Based on Worksheet and the Independent Torrance Test for creativity. At the beginning of the lesson given an explanation of work instructions followed by group organizing. The group used the The ICARE Practice Based on Worksheet to conduct physics experiments with the guidance of lecturers. The experimental results of each group were presented by each group and continued with interactive debates between presenters and comparison groups. Input provided by lecturers and students is used to make reports individually. The Independent Torrance Test is given as a pretest and posttest. Increased creativity is an effect of applying the The ICARE Practice Based on Worksheet in experimentation. The gain based test results were obtained from the posttest and pretest ratings. The test results show that improvement through creativity indicators is achieved on Originality, Flexibility, and Elaboration. The indicator has an increase of more than 70 % of the number of students. This increase does not occur in the Fluency indicator.

Keywords
ICARE; Worksheet; Creativity; Physics Experimental

Topic
Physics related sciences

Link: https://ifory.id/abstract/wtcyHF48xMTg

Corresponding Author
Nirwan Syarif

Institutions
Universitas Sriwijaya, Universiti Teknologi Malaysia

Abstract
The performance of symmetrical and asymmetrical supercapacitors were determined by using electrochemical impedance spectroscopy, cyclic voltammetry, and charge-discharge galvanostatic methods. The construction of asymmetric supercapacitor was a thick layer electrode of paper-bark wood carbon sheets as anode, etched aluminum foil as cathode and gel contained BaCO3 as electrolyte. The symmetric used carbon thick layer both as anode and cathode. The electrodes were made of carbon - graphite mixture with ratio of 3 : 7, and 10% of binder, supported by a glass plate. The results of charging – discharging tests showed that the symmetrical 3 : 7 supercapacitor has highest capacitance value in ie 0.434 F for 10% BaCO3 electrolyte in polyvinylalcohol media. Cyclic voltammetry measurement showed that the symmetrical has the highest capacitance value i.e., 0.0138 Fg-1. The charge-discharge galvanostatic measurement showed that the symmetrical has 1.445 of charging slope and 1.344 of discharging slope suggesting the charging rate faster than the discharge rate.

Keywords
Ultracapacitor, potensiostat, electrochemistry, electrolyte, polymer

Topic
Nano-materials and applications

Link: https://ifory.id/abstract/9vckndg7C8mf

Corresponding Author
Windri Handayani

Institutions
1 Departemen Biologi, Universitas Indonesia, Depok 16424
2 Departemen Fisika, Universitas Indonesia, Depok 164241

Abstract
Matoa leaves, beside of their medicinal properties it can so be used for biosynthesis of silver nanoparticles. The factors that play role in the biosynthesis process is pH. Therefore, this study carried out the biosynthesis of silver nanoparticles using leaves extract of Matoa and the effect of pH on the shape, size and stability of the silver nanoparticles. Biosynthesis was carried out by mixing 2% Matoa extract and 1 mM AgNO3 solution which then incubated for 24 hours. There are four variations of pH used, 4, 7, 9 and 11. Silver nanoparticles were characterize based on color changes, UV-Vis spectrophotometers, TEM (Transmission Electron Microscopy), and PSA (Particle Size Analyzer). The photos and UV-Vis spectra of pH treatment showed a change in the color of the solution to yellow-brown and had absorption at a wavelength of 400-500 nm indicating the formation of silver nanoparticles. The TEM results showed that the boiled water of the Matoa leaves tend to have spherical silver nanoparticles. The higher the pH of the reaction environment, smaller silver nanoparticles formed, and the stability of the silver nanoparticles produced tends to be unstable except for AgNP in pH 9 which is moderately stable and has a good monodispersity.

Keywords
Pometia pinnata, Silver nanoparticles, Biosynthesis, pH

Topic
Nano-materials and applications

Link: https://ifory.id/abstract/gWet7yhP6wmb

Corresponding Author
Eakgapon Kaewnuam

Institutions
1 Physics Program, Faculty of Science and Technology, Muban Chombueng Rajabhat University, Ratchaburi, 70150, Thailand
2 Physics Program, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand
3 Center of Excellence in Glass Technology and Materials Science (CEGM), Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand

Abstract
In this work, lithium bismuth aluminium borate glasses doped with different concentration of Er3+ were prepared to investigate the physical, chemical unit, optical and luminescence properties. All glasses were prepared by melt-quenching method. Glass density is in a range of 3.20 – 3.27 g/cm3 with no obvious relation to Er2O3 concentration. The FTIR spectra confirms the tetrahedra BO4 borate unit appearing in glass network. This BO4 unit tend to increase with increment of Er2O3 content. Er3+ in glass absorb photon in visible light and near-infrared region, confirmed by the absorption spectra. The emission and excitation spectra perform the infrared emission of Er3+ under 523 and 975 nm excitation. The strongest emission with 1536 nm belongs to 1.00 mol% Er2O3 doped glass that was excited by photon with 523 nm. This developed glass possesses the good potential for using as the source and medium material for infrared emitting and communication device.

Keywords
Borate glass, Erbium ion, infrared emission

Topic
Optical, luminescence, Electronic Materials and applications

Link: https://ifory.id/abstract/YncpCJtKTBuq

Corresponding Author
PRISTANUCH KASIAN

Institutions
744 Sura Narai Rd, Nai-muang, muang, Chang Wat Nakhon Ratchasima 30000, pristanuch.ka[at]rmuti.ac.th
Department of Applied Physics, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology Isan

Abstract
Zn-doped titanate nanowires (TNWs) with the chemical formula of ZnxTi3-xO7 (Na0.96 H1.04 × 3.42H2O) where x = 0, 0.05, 0.1, 0.2, and 0.3 were synthesized by a hydrothermal method at a temperature of 130 °C for 24 h. The synthesized samples were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) techniques. It was found that, the diameter and length of the nanotubes were in scale of nanometer. Electrochemical properties of prepared samples were investigated by cyclic voltammetry (CV), galvanostatic charge - discharge (GCD) and electrochemical impedance spectra (EIS) methods. The specific capacitance of 23 F g-1 (at 1 mV s-1) was observed for Zn-doped TNWs.

Keywords
Energy storage, Zn-doped TNWs, Electrochemical properties

Topic
Nano-materials and applications

Link: https://ifory.id/abstract/AuCEFbQpBdqk

Corresponding Author
Riri Jonuarti

Institutions
a) School of Energy, Bandung Institute of Technology
Jalan Ganesha 10, Bandung 40132, Indonesia
*riri.jonuarti[at]gmail.com

b)Department of Physics, Universitas Andalas, Jalan Universitas Andalas, Limau manis, Padang, 25163,
Indonesia

Abstract
A density functional theory (DFT) method was used to study the structures, stability and band gaps of the ultra-small armchair boron nitride nanotubes (BNNTs). We define the ultra-small size of the armchair boron nitride nanotubes (BNNTs) as a nanotube with diameter less than 1 nm. Each armchair nanotube-s stability and band gap was obtained varied by varying the size of nanotube diameters up to 1 nm. The larger size of diameter the higher stability and wider armchair nanotubes band gap. The results of the ultra-small armchair calculation confirm the same trend of properties with the available calculation data of ultra-small zigzag nitride nanotubes (BNNTs).

Keywords
The density functional theory (DFT); ultra-small armchair boron nitride nanotubes (BNNTs); structures; stability; band gap

Topic
Computational and characterization of materials

Link: https://ifory.id/abstract/2HdNpEBJqWjx

Corresponding Author
Perdinan Sinuhaji

Institutions
Universitas Sumatera Utara

Abstract
Abstract The purification of zinc oxide has been carried out from zinc dross waste by pyrometallurgy method. The amount of zinc dross waste was cleansed by using aqua DM liquid with ratio of 1:10, then this amount was characterized using XRF to determine chemical compounds contained within the 90% of zinc dross waste, while impurity compositions of Fe, Al, and Mg were found. Hence, the amount of zinc dross waste was mixed to carbonized coffee within two ratios, i.e. 87.5%wt: 12.5%wt, and 75%wt: 25%wt. The mixture samples were then dissolved by aqua DM, followed by milling treatment by performing Planetary Bill Mill for 40 minutes, so that the muddy-phase were obtained. This sample was then filtered and it was heated inside an oven at 100oC for 24 hours to powder. The mixture powder of zinc dross and carbon was then placed in pyrolysis vessel at 1200oC for 2.5 hours. The obtained amount of zinc oxide powder was characterized by using XRF, and this has 98% of purity with impurities element i.e Al2O3, Fe2O3, MgO, and SiO2. Thermal testing was performed for ZnO sample by using DT instrument to investigate the effect heating to the reaction events. The analysis of DTA showed that the mixture sample of zinc dross and carbon had reaction sequences at 800oC. The morphological analysis conducted by SEM and OM depicted that ZnO has agglomeration characteristics with uniformity shape among particles. The size of the particles is between 1,900 µm to 9,378 µm.

Keywords
: zinc oxide, zinc dross, carbonized coffee, pyrometallurgy, purification

Topic
Metal alloys, ceramics and composite materials

Link: https://ifory.id/abstract/XWDFNVHpemcd

Corresponding Author
Tosawat Seetawan

Institutions
a Instrumentation and Electronic Laboratory, Department of Physics, Institut Teknologi Sepuluh Nopember, Arief Rachman Hakim Rd, Surabaya, 60111 East Java Indonesia
b Thermoelectric Research Laboratory, Center of Excellence on Alternative Energy, Reseach and Development Institution, Sakon Nakhon Rajabhat University, 680 Nittayo Rd, Mueang District, Sakon Nakhon 47000, Thailand
c Program of Physics, Faculty of Science and Technology, Sakon Nakhon Rajabhat University, 680 Nittayo Rd, Mueang District, Sakon Nakhon 47000, Thailand

Abstract
Research on crystal structures and thermoelectric properties has been carried out using BiTe material. The sintering method used is hot press. Hotpress pressure comes from the bottom up. Temperature variations used in hotpress are 400, 450 and 500°C. Analysis of crystal structure used XRD. Based on the XRD results, the result is that the crystal structure of BiTe bulk is hexagonal. Thermoelectric properties measurements used ZEM-3. The sample is measured in a temperature range of 50-200°C. Based on the measurements, the sample with hot press 500°C has the highest Seeback coefficient and power factor values which are -71 uV/K and 3.6 x 10-4 W/mK^2, respectively. The sample has the best performance at room temperature and has decreased performance with increasing temperature. While the best electrical resistivity value is owned by the sample with hot press 450°C with a value of 1.28 mΩ cm at room temperature. Overall, the higher the temperature used when sintering, the better the performance produced. Thus, the BiTe material can be considered as a thermoelectric material.

Keywords
Harvesting Energy, Thermoelectric technology, Bismuth Telluride

Topic
Energy and environment materials

Link: https://ifory.id/abstract/QWPc6vLAjGCY

Corresponding Author
Kunchit Singsoog

Institutions
a) Thermoelectric Research Laboratory, Center of excellence on Alternative Energy, Research and Development Institute, Sakon Nakhon Rajabhat University, 680 Nittayo Road, Mueang District, Sakon Nakhon, 47000, Thailand.
*kunchitsingsoog[at]yahoo.com
b) Program of Physics, Faculty of Science and Technology, Sakon Nakhon Rajabhat University, 680 Nittayo Road, Mueang District, Sakon Nakhon, 47000, Thailand.

Abstract
The Mn1-xAgxSi1.75-yBiy (x = y = 0, 0.01, 0.02, 0.03, 0.04, and 0.05) materials were synthesized by ball milling and hot press method. The crystal structure and thermoelectric properties were analyzed it was found that the XRD patterns of all samples show mixes phase between MnSi1.75 for main phase of tetragonal structure and MnSi for secondary phase. The relative density of all samples were higher than 92%, indicating a good method for preparing high density samples. The Seebeck coefficient (S) and electrical resistivity of Ag and Bi doped Mn1-xAgxSi1.75-yBiy can be increased. The highest of S value and power factor at 673 K revealed that Mn0.98Ag0.02Si1.73Bi0.02 sample were about 119 V K-1 and 3.97 × 10-5 Wm-1K-2, respective. The highest power factor gave higher values than non-doped about 45.35 %. The Mn0.98Ag0.02Si1.73Bi0.02 sample is the most suitable for p-type of thermoelectric device fabrication.

Keywords
Thermoelectric; Generator; Refrigeration; Manganese silicide

Topic
Energy and environment materials

Link: https://ifory.id/abstract/ALreJXhEqdVg

Corresponding Author
Tosawat Seetawan

Institutions
a Instrumentation and Electronic Laboratory, Department of Physics, Institut Teknologi Sepuluh Nopember, Arief Rachman Hakim Rd, Surabaya, 60111 East Java Indonesia
b Thermoelectric Research Laboratory, Center of Excellence on Alternative Energy, Reseach and Development Institution, Sakon Nakhon Rajabhat University, 680 Nittayo Rd, Mueang District, Sakon Nakhon 47000, Thailand
c Program of Physics, Faculty of Science and Technology, Sakon Nakhon Rajabhat University, 680 Nittayo Rd, Mueang District, Sakon Nakhon 47000, Thailand

Abstract
From the research to determine the thermoelectric properties and crystal structure of SbTe material synthesized by ball mill at 350 rpm for 10 hours and sintered with hot press. The hot press method was varied at the time of hot press for 1, 2 and 3 hours. The hot press temperature is 400 °C with a pressure of 25 MPa. Then all materials were tested by XRD and ZEM 3. Based on the XRD test performed, all materials had hexagonal crystal structures. From ZEM 3 measurement known that the best thermoelectric properties value is in sample 3 which has an electrical resistivity 0.35 mΩ cm at 331 K, Seebeck coefficient 147 uV/K at 473 K and power factor 4.53 mW/mK^2 at 331 K.

Keywords
Harvesting Energy, Thermoelectric technology, Antimony Telluride

Topic
Energy and environment materials

Link: https://ifory.id/abstract/Yx7tHEXDRGnz

Corresponding Author
Setyawan Purnomo Sakti

Institutions
Department of Physics
Brawijaya University
Jl Veteran, Malang 65145, Indonesia
sakti[at]ub.ac.id

Abstract
High shear modulus coating material does not provide loading effect to the Quartz Crystal Microbalance sensor. The condition is met when the coating material was glassy and the layer was homogeneous. Polystyrene is considered as a glassy coating material when used on 10MHz Quartz Crystal Microbalance. Homogeneous and compact polystyrene coatings that are glassy can be obtained using the spin coating method. The films rigid condition is shown by the sensor impedance value at the series resonance frequency after coating. However, using ultrasonic spray coatings, it was known that polystyrene films are formed not as homogeneous as when coated using spin coatings. We observed that Quartz Crystal Microbalance was damped by the polystyrene film when the coating film was not evenly distributed over the sensor surface, especially on the sensor surface above the electrode. The minimum impedance of the QCM sensor increased significantly. The unevenness of the coating causes the damping effect on the QCM sensor. The minimum sensor impedance before coating was less than 15(Omega). When the polystyrene layer was uneven, we found that the impedance increased by more than 25 (Omega). The results showed that the distribution of polymer layers on the sensor surface is one of the important factors that must be considered to avoid the effect of damping on the sensor. The measurement results showed that the sensor has a negative mass effect.

Keywords
QCM sensor; uneven coating; polystyrene

Topic
Sensing materials and applications

Link: https://ifory.id/abstract/kXCLyq9jdzAP

Corresponding Author
Yuni Warty

Institutions
Institut Teknologi Bandung

Abstract
The appropriate treatment method for patient with urinary stones can be determined from the information of the mineral composition of urinary stones. The prediction of the stone type could improve the selection of the interventional modalities. The aim of the study was to determine the type of the urinary stone for each layer based on the value of Housefield Units (HU) from micro CT-SkyScan images. Five samples were cleaned with 75% alcohol and distilled water. Micro skyScan 1173 was used to scan urinary stones with applied current and voltage of 66 mA and 120 kV respectively. NRecon software was used to reconstruct the projected image. Region of Interest (ROI) was set at each layer and analyzed both qualitatively and quantitatively. The determination of chemical constituents of stones/fragments was performed using Energy Dispersive X-Ray Spectroscopy. The chemical compositions of calcium oxalate, a mix of calcium oxalate and calcium phosphate, struvite, uric acid, and a mix of uric acid and calcium phosphate were accurately identified based on the micro SkyScan images with the mean HU for each composition were 1356 ± 188, 1038, 391 ± 151, 391 ±249, and 1384 ± 195, respectively. Micro SkyScan images could predict the chemical composition for each layer of urinary stones. However, more samples are needed for clustering various types of urinary stones based on HU value.

Keywords
micro CT-SkyScan, Housefield Units, Energy Dispersive X-Ray Spectroscopy

Topic
Biomaterials and applications

Link: https://ifory.id/abstract/vraqfRDX2uz3