Table of contents

Preface: Proceedings of the International Symposium on Frontier of Applied Physics (ISFAP) 2016

The International Symposium of Frontier of Applied Physics (ISFAP) 2016 was a scientific meeting that is technically organized by Research Center for Physics in conjunction with Indonesian Science Technology Festival organized by Deputy of Engineering Sciences, Indonesian Institute of Sciences (LIPI). ISFAP was held on 3 - 5 October, 2016 at Indonesia Convention Exhibition (ICE), Serpong, Indonesia. The event was supported by Indonesian Physical Society (HFI), Indonesian Institute of Sciences (LIPI), and Indonesian Society for Microscopy (Ina-SM).

This symposium aimed to bring together researchers, academicians, and scholars all around the world to share information and their research results. This event was also expected to become a beneficial media in exchanging their innovative ideas and build research collaborations in the future. The symposium covered all scientific and technical activities in physics – from basic to the advanced applications – especially those related to advanced material sciences for energy, nanotechnology, geophysics, lasers and optoelectronics, magnetism and superconductivity, hybrid, ceramics, and composite materials, material process engineering, surface and corrosion science.

We specially invited 4 scientists as keynote speakers, 4 researchers as invited speakers, and 4 researchers as selected speakers from various countries to share their knowledge to all participants. The total participants attending this symposium were 133 persons. This symposium has successfully attracted 109 submitted papers. Papers that have been presented in the ISFAP 2016 were eligible for publishing in IOP Journal of Physics: Conference Series. The editorial board has decided to accept 75 papers from Indonesia, Philippines, Nigeria, South Africa, Saudi Arabia, Egypt, Malaysia, Germany, and Taiwan. The accepted papers have passed through strict reviewing process by scientific committee of this symposium. EDAS system has been used to facilitate the submission, reviewing, and revision processes.

We would like to appreciate all of our co-organizers, supporting societies, sponsors, and Research Center for Physics staffs who have contributed generous amount of grants and effort to support us during the symposium. We hope this symposium has successfully enabled us to share and communicate our knowledge and skills and to build collaborations among the participants. We are looking forward to welcoming you in Indonesia again. See you in ISFAP 2017!

Chief Editor

Febty Febriani (febty.febriani@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Keisuke Takahashi (Keisuke.takahashi@eng.hokudai.ac.jp)

Hokkaido University

Graduate School of Engineering

North 13, West 8

Sapporo, 060-8628

Japan

Peng Han (hanpeng407@gmail.com)

Institute of Statistical Mathematics

Risk Analysis Research Center (Statistical Seismological Research Project)

10-3 Midori-cho, Tachikawa

Tokyo 190-8562

Japan

Siwei Chen (chen-sw@criepi.denken.or.jp)

Central Research Institute of Electric Power Industry

Materials Science Research Laboratory

2-11-1 Iwadokita, Komae-shi

Tokyo 201-8511

Japan

Xinhong Qiu (qxinhong@gmail.com)

Wuhan Institute of Technology

School of chemistry environmental engineering

No.693, Xiongchu Avenue, Hongshan District Wuhan, Hubei Province, P.R.

China

Mohsen Farahat (mohsen105@hotmail.com)

Central Metallurgical Research and Development Institute (CMRDI)

Mineral Processing and Agglomeration

P.O. Box 87 Helwan, Cairo

Egypt

Young-Ho Ko (yhko@etri.re.kr)

Electronic and Telecommunications Research Institute (ETRI)

Photonic/Wireless Convergence Components Research Department

218 Gajeong-ro, Yuseong-gu, Daejeon, 34129

Korea

Eni Sugiarti (eni.sugiarti@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Titi Anggono (titi.anggono@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Isnaeni (isnaeni@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Yuliati Herbani (yuliati.herbani@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Ferensa Oemry (ferensa.oemry@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Hubby Izzuddin (hubby.izzuddin@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Widi Astuti (widi.astuti@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research and Development Division for Mineral Technology

Jl. Ir Sutami Km.15 Tanjung Bintang, Lampung Selatan

Lampung. 35361

Indonesia

Wahyu Bambang Widayatno (wahyu.bambang.widayatno@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Deni Shidqi Khaerudini (deni.shidqi.khaerudini@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Kirana Yuniati Putri (kirana.yuniati.putri@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Fredina Destyorini (fredina.destyorini@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Nurfina Yudasari (nurfina.yudasari@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Qolby Sabrina (qolby.sabrina@lipi.go.id)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

Risma Sundawa (risma.sundawa@gmail.com)

Indonesian Institute of Sciences (LIPI)

Research Center for Physics

Komplek PUSPIPTEK Serpong,

Tangerang Selatan 15314,

Indonesia

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Synthesis and characterization of 8YSZ (8%mol Y₂O₃ – ZrO₂) and 5GDC (5%mol Gd₂O₃–CeO₂) combination in the form of composite and dissimilar bulk using sonochemistry assisted sol-gel method have been done. 8YSZ and 5GDC powders were produced from sol-gel route method. Each of the powder was then ultrasonicated for 30 hours with 25kHz±50Hz of frequency and 39% of amplitude. Toluene was used as a solution for the ultrasonication process. 8YSZ/5GDC composite was made by mixing the powders of 50%:50% in weight, and afterward compacted become a pellet. 8YSZ/5GDC dissimilar bulk was made by connected between 8YSZ pellet and 5GDC pellet at a flat part, and afterward re-compacted become a single pellet. Then, the pellets were sintered at 1400°C of temperature for 3 hours. The results showed that the ionic conductivity of the composite is higher than the dissimilar bulk.

Kapton-polyimide films have been modified by using ion implantation of Fe and Gd ions at dose 1 × 10¹⁷ ions/cm² and energy ions 30 keV. From X-ray diffractions (XRD) were verified the existence phases such as iron oxide, or Gd-oxide and graphitic carbon. Vibrating sample magnetometer (VSM) measurement the films showed a paramagnetic behavior. Microwave absorption (MWA) properties were measured by vector network analyzer (VNA) at X band range (8-12GHz). VNA measurement results showed the enhancement of MWA from -22dB for Kapton original film to -35dB for S11 vector direction and until -40 dB for S22 vector direction of modified Kapton film by Fe and Gd ions. It can be concluded that the nanostructure of embedded Fe-oxide or Gd-oxide nanoparticles on the near surface of Kapton film take a role and gives a rise the MWA properties of film.

In this paper, we aim to fabricate cotton thread based sensor for proprioceptive application. Cotton threads are utilized as the structural component of flexible sensors. The thread is coated with multi-walled carbon nanotube (MWCNT) dispersion by using facile conventional dipping-drying method. The electrical characterization of the coated thread found that the resistance per meter of the coated thread decreased with increasing the number of dipping. The CNT coated thread sensor works based on piezoresistive theory in which the resistance of the coated thread changes when force is applied. This thread sensor is sewed on glove at the index finger between middle and proximal phalanx parts and the resistance change is measured upon grasping mechanism. The thread based microelectromechanical system (MEMS) enables the flexible sensor to easily fit perfectly on the finger joint and gives reliable response as proprioceptive sensing.

Flexible substrates have many promising applications in sensing, electronics, and electromagnetic shielding and energy storage among many others. Paper can serve as substrate for these kinds of technologies offering a cheaper alternative. In this study, Zinc oxide (ZnO) was successfully deposited on graphite drawn on paper using electrophoretic deposition (EPD). Graphite from commercially-available pencil was drawn on paper. Graphite drawn on paper was used as electrodes for the EPD process. High-voltage power supply was used as source while ground ZnO in acetone was used as suspension in the deposition process. Scanning electron microscopy (SEM) and Energy dispersive x-ray spectroscopy (EDX) results reveal the deposition of ZnO on Graphite. In addition, the electrical contact of the ZnO-graphite interface showed Ohmic behaviour by two-point probe method.

Electrochemical performance of natural graphite as anode material in the Li-ion battery has been modified by coating this particle with amorphous carbon through two step synthesis process. Citric acid as the amorphous carbon source was mixed with natural graphite (NG) in the ethanol solvent at 80 °C using magnetic stirrer. In the first step, the mixture of NG and CA were dried at 350 °C for 5 hours under argon atmosphere to evaporate the solvent. This dried mixture was then sintered at different temperature i.e. 500 °C (labeled CNG500), 600 °C (CNG600) and 700 °C (CNG700) under argon atmosphere to form amorphous carbon layer on the surface of NG. The crystal structure and morphology of the particles were characterized by using XRD, SEM and TEM. Electrochemical performance and charge-discharge of amorphous carbon-coated graphite has been evaluated by cyclic voltammetry and WBCS 3000, respectively. Cyclic voltammogram showed the working potential and redox reaction peak of the sample. Charge-discharge data was obtained to determine the specific capacity of the sample at 0.1C.

Activated carbon is materials that have wide applications, including supercapacitor materials, absorbent in chemical industry, and absorbent material in the chemical industry. This study has carried out for the manufacturing of activated carbon from inexpensive materials through efficient processes. Carbon material was made from coconut fibers through pyrolysis process at temperature of 650, 700, 750 and 800°C. Aim of this study was to obtain carbon material that has a large surface area. Pyrolysis process is carried out in an inert atmosphere (N₂ gas) at a temperature of 450°C for 30 minutes, followed by pyrolysis process in an ammonia atmosphere at 800°C for 2 hours. The pyrolysis results showed that the etching process in ammonia is occurred; as it obtained some greater surface area when compared with the pyrolisis process in an atmosphere by inert gas only. The resulted activated carbon also showed to have good properties in surface area and total pore volume.

ZnO nanorods is a low cost II-VI semiconductor compound with huge potential to be applied in optoelectronic devices i.e. light emitting diodes, solar cells, gas sensor, spintronic devices and lasers. In order to improve the electrical and optical properties, group II, III and IV elements were widely investigated as dopand elements on ZnO. In this work, magnesium (Mg) was doped into ZnO nanorods. Samples were prepared firstly by deposition of undoped ZnO seed layer on indium thin oxide coated glass substrates by ultrasonic spray pyrolysis method and then followed by the growth of ZnO nanorods doped by three different Mg concentrations by hydrothermal method. Based on the morphological, microstructural and optical characterizations results, it is concluded that the increase of magnesium concentration tends to reduce the diameter of ZnO nanorods, increases the bandgap energy and decreases the UV absorption the luminescence in UV and visible range.

Pulse charging methods has been developed as one of the fast charging methods for Lithium ion battery. This technique applies the continuous constant current pulse with certain pulse width until the battery fully charged. In this research, four Lithium polymer batteries of same type and capacity were used and subjected by several current pulses as a variable. The phenomenon of capacity loss as an effect of charging method was analysed every ten charge-discharge cycles. Four batteries were charged using constant current (1C) for 30 minutes to fill half of the total capacity, which then continued by pulse current of different pulse width in order to reach full capacity of each battery. Constant current charging for one hour was also applied to each battery as a comparison with that of pulse current charging data. The similar degradation patterns on battery capacity were observed. Nevertheless, the percentage of capacity loss is different. In conclusion, this method can be considered as one of the effective charging method, owing to the smallest capacity loss and shorter charging time.

Metal nanoparticles have unique optical properties called Localized Surface Plasmon Resonance (LSPR). Gold nanorods have better plasmonic property for sensor application due to its longitudinal resonance mode is more sensitive to environment dielectric properties changes. Controlling the aspect ratio during the synthesis process becomes important because it would determine the plasmonic properties of the gold nanorods. In this study, gold nanorods have been successfully synthesized in the solution with three different concentrations of HNO₃ and CTAB. Increasing the concentration of HNO₃ and CTAB tends to increase the length, diameter, aspect ratio and yield of gold nanorods. All samples appeared to have a peak of transversal mode at the wavelength of 510 nm. However, the longitudinal mode peaks could not be seen in this observation.

The performance of Gas Diffusion Layer (GDL) synthesized from coconut waste. Gas Diffusion Layer (GDL), produced from coconut waste, as a part of Proton Exchange Membrane Fuel Cell (PEMFC) component, has been characterized. In order to know the performance, the commercial products were used as the remaining parts of PEMFC. The proposed GDL possesses 69% porosity for diffusion of Hydrogen fuel and Oxygen, as well as for transporting electron. With the electrical conductivity of 500 mS.cm^-1, it also has hydrophobic properties, which is important to avoid the reaction with water, with the contact angle of 139°. The 5 × 5 cm² GDL paper was co-assembled with the catalyst, Nafion membrane, bipolar plate, current collector, end plate to obtain single Stack PEMFC. The performance was examined by flowing fuel and gas with the flow rate of 500 and 1000 ml.min^-1, respectively, and analyse the I-V polarization curve. The measurements were carried out at 30, 35, and 40°C for 5 cycles to ensure the repeatability. The results shows that the current density and the maximum power density reaches 203 mA.cm^-2 and 143 mW.cm^-2, respectively, with a given voltage 0.6 V, at 40°C.

The interactions between electron and specimens produce wide range of secondary signals from the specimen that can be used in analytical electron microscopy. These signals will give us chemical information and electronic structure information of specimen atoms. Two techniques which based on these secondary signals, X-rays energy-dispersive spectroscopy (XEDS) and electron energy-loss spectroscopy (EELS), are very powerful to be used for characterization materials. These two techniques are complementary each on the other. The former is very useful to quantify heavy elements and the other is very suitable to identify light elements as oxygen and carbon. In this report, we demonstrated the capability of these techniques to investigate microstructure evolution during the oxidation process of thin film Cr2AlC at 1320 °C. This thin film belongs to MAX phase, a new class material, and becomes a promising candidate for coating applications since it exhibits a good oxidation resistant.

The alpha-beta Ti-6Al-4V alloy has been used as biocompatible materials due to its excellent mechanical properties, corrosion resistance, and lower specific strength than other metallic biomaterials such as stainless steel and Co-Cr alloy. However, the concern to the toxic element of vanadium led to the development of a new alpha-beta Ti6-Al-6Nb alloy. This paper presented microstructural, mechanical properties and biocompatibility of as cast Ti-6Al-6Nb alloy. The materials were characterized by scanning electron microscopy, optical microscopy, microhardness test, and X–ray diffraction. In addition corrosion test was performed by using Hank's solution at 37 °C and pH 7.4. The result showed that Ti-6Al-6Nb alloy could potentially used for biomedical application due to its good mechanical properties and corrosion rate.

This study reported synthesis and characterization of PVDF (polyvinilidine fluoride) nanofiber membrane using electrospinning method for Li-ion rechargeable battery separator. Electrospinning equipment system consists of a DC high voltage (HV - DC), a controllable spinner and a plate collector. The effects of the applied voltage on morphological property, porosity and thermal property were systematically investigated. The application of DC voltage at a range of 13 to 17 kV resulted the one-dimension nanostructure of the PVdF nanofiber. The produced PVdF nanofiber membrane separators are evaluated to have a higher level of porosity (86 – 93%) and a good thermal shrinkage property in comparison to Polypropylene (PP) microporous membrane separator. The produced PVdF membrane separators were assembled into the LiFePO₄ cells and demonstrated high charge-discharge capacities at room temperature with the coulombic efficiency reaching 80 %.

Zinc oxide (ZnO) is a promising semiconductor due to its tunable optical properties. Among semiconductor nanostructures, one-dimensional structure such as ZnO nanorods becomes the main focus due to their wide potential application. Cu doped ZnO has attracted much attention recently because of its interesting properties, such as room temperature ferromagnetism, multiferroics properties and green emission. In this work, we deposited ZnO nanoseeds on indium tin oxide coated glass substrates and then ZnO nanorods were grown and doped with three different Cu concentrations (1, 4 and 7 at. %) by hydrothermal method. The scanning electron microscope showed that ZnO nanorod were grown with a hexagonal shape with diverse growth orientation. The X-ray diffraction analysis reveals that the addition of Cu doping tends to decrease the crystallite size and the lattice parameter. Generally, Cu doping reduces the absorbance at ultraviolet wavelength region except on the ZnO nanorods with 4% Cu. The addition of Cu also increases the bandgap energy and decreases the luminescence intensity in UV and visible regions, that is a sign that number of radiative transitions and the natural defects have been reduced.

Rice husk in the Philippines is considered as an agricultural waste. In order to utilize the material, one common technique is to carbonize these rice husks to produce charcoal briquettes. These materials are porous in nature exhibiting electrical properties from carbon structures. In this study, rice husk charcoals (RHC) were deposited on different metal substrates (Al, Cu, Zn) via a simple solution casting method. The deposited RHC on metal substrates was observed using Scanning Electron Microscopy (SEM). The films were characterized using two-point probe technique and the I-V curves were plotted. Al-RHC films appear to deviate from an ohmic behaviour while Zn-RHC and Cu-RHC showed diode-like behaviours.

Effect of coating thickness of Al-doped Li₄Ti₅O₁₂ (LTO) sheet on the electrochemical performance of battery cells is reported. A 0.025 mol Al-doped LTO powder was synthesized by solid state reaction method, for the anode sheet was made by the doctor blade method. The sheet manufacturing was carried out by varying the coating thickness from 100, 200, 300 and 400 μm to determine the effect on the electrochemical performance of the battery cell. The analysis of phase was conducted by X-ray diffraction (XRD); for electrochemical performances were conducted by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge discharge (CD) method. XRD analysis showed that there are two phases formed, i.e. LTO and rutile phases (TiO₂) of 75.6% and 24.4%, respectively. EIS results showed that the thicker the coating layer, the conductivity of the sample become slower. Furthermore, the results indicate that the sample with thickness of 100, 200 and 300μm indicated sharp redox peak, and 400 μm showed wide redox peaks. The specific capacity and specific power of the half cell battery decreases with the increasing of coating thickness. The best cell capacity is obtained by sample with 100 μm thickness with specific discharge capacity of 134.3 mAh/g.

Dye-sensitized solar cells (DSSCs) have acquired great prominence as favourable low-cost photovoltaics due to their ease of fabrication, all- year -availability, ease of obtaining raw materials and adjustable optical properties like transparency and colour. These advantages coupled with the ability to work under poor lighting makes them a suitable candidate for next generation of research. In this research, C.acuminata-sensitized photo anodes play an important role for achieving high performance since the porous metal oxide films provide a large specific surface area for dye loading and the possibility to extend the absorption threshold of past studies of sensitizers. The doctor blade method and high-temperature sintering were some of the methods used in the fabrication of the photo anode. A study of the performance of the C.acuminata-DSSCs with four different electrolyte sensitizers based on iodide redox mediator is determined. The result is DSSCs that exhibit a maximum power output of 39.37 W, fill factor of 0.7 and a power conversion efficiency of 0.6% under unfavourable sunlight intensity conditions and photo-degradation of about 37.5 % in absorbance after 425 suns.

This paper reports the surface modification of high silica ZSM-5 zeolite, particularly emphasizing the effect of cation type on selective conversion of biomass-derived oil. XRD spectra of the NaOH-treated HZSM-5 showed notable crystallinity decrease at specific crystal plane orientation. The N₂-physisorption tests confirmed mesoporosity evolution as NaOH concentration was increased. NH₃-desorption tests revealed a significant change on surface acidity which involved realumination and cation replacement processes. The utilization of untreated HZSM-5 as well as hierarchical NaZSM-5 for catalytic conversion of bio-oil showed the effect of cation type and mesoporosity on chemicals distribution. The untreated HZSM-5 showed high selectivity to aromatics, which degraded gradually due to deactivation and poisoning of the acid sites. Meanwhile, hierarchical NaZSM-5 showed high selectivity to phenolic compound, which became more stable for 0.4M NaOH-treated zeolite (Na04). The current findings provide an additional insight on the potentials of NaZSM-5 for bio-oil valorization.

Solid polymer electrolytes comprising of poly(vinylidene fluoride) (PVdF) and lithium bis (oxalato) borate (LiBOB) have been prepared using solution casting technique. Having an important role in lithium-ion battery system, electrolyte is required to have high ability to transfer lithium ions between electrodes. Safety aspect is the main reason for the development of solid polymer electrolyte as advancement from conventional liquid electrolyte. Nevertheless, solid polymer electrolyte generally has lower conductivities compared to liquid electrolyte. In this research, ceramic additives, as well as plasticiser materials, have been incorporated within the solid polymer electrolyte system to improve its conductivity. Addition of TiO2 filler has proven to increase ionic conductivity by two orders of magnitude. Further improvement was seen in the incorporation of PEG plasticiser, where ionic conductivity was enhanced by three orders of magnitude.

Degradation activation energy of PEG-Cristobalite composites was investigated using Dynamic Mechanical Analysis (DMA) instrument at multi-frequency shear mode. The applied frequencies were 1, 10, 100, and 200 Hz. The cristobalite of as much as 20% and 40% by weight was used as the filler of the composites, while PEG 4000 was the matrix. Results showed that additional of cristobalite improved the storage modulus (G') of the composites almost five times of the pure PEG 4000. Moreover, such addition and higher applied frequency shifted glass transition temperature (T_g) to higher values. Furthermore, the multi-frequency measurement provided the degradation activation energy of the samples, where the highest value was reached by the 40% sample, i.e. 571.4 kJ. This result implied that there was a certain energetic barrier from the filler that the structural units of polymer need to surmount collectively before its viscous flow occured.

TiO2 in powder form was preferred due to its flexibility and easy handling. TiO2 powders with controlled crystal phase were successfully synthesised by ultrasonic spray pyrolysis from titanium tetraisopropoxide (TTIP) precursor. The effect of various acid solvents (nitric acid, acetic acid and citric acid) in relationship with crystal compositions have been well-studied. This experimental study suggested that the ratio of anatase phase achieved from TiO2 prepared by nitric, acid acetic acid and citric acid solvent are 85%, 39% and 27% respectively. Spurs-Myers equation used to determine the anatase-rutile phase. Crystal sizes were calculated using Scherer equation. Both of ratio and crystal size were estimated from corresponding X-ray diffraction pattern. Precipitation and chelating process were the keys to determine the last composition of TiO2.

Doping is one of the effective methods to modify the physical properties of ZnO material in order to extend its applications. An investigation on Zn_1-xM_xO (M = Gd, Mg and x = 0.00, 0.03) nanopowders that have been synthesized by sol-gel method and sintered at 600 °C for 2 hours was reported. The decomposition process of the dried gel system was investigated by thermal gravimetric analysis (TGA) and the nanopowders with different heating temperature were studied using FT-IR spectroscopy. The crystal structure of the nanopowders after sintering at 600 °C was obtained using X-ray diffraction (XRD). The TGA curves of the samples showed the various weight loss regions corresponding to the removal of starting materials and no weight loss was observed in the temperature range of 300 to 800 °C which corresponded to the phase-crystallization step. The FTIR spectra showed that ZnO band was assigned to the stretching frequency at 669 cm^-1 while Gd/Mg doped ZnO was at 668 cm^-1 and 666 cm^-1. From the XRD studies, the crystal structure of the samples indicated single phase ZnO crystalline and confirmed hexagonal wurtzite structure (space group of P6₃mc).

M-Silicate (M = Mg, Ca) has been prepared by exchange metal reaction from M-Chloride salts and sodium silicate. The resulting white solid of chloride salts then heated at 700, 800, 900 and 1000 °C. Due to increase the porosity of M-Silicate, 1,2-propanediol, oleic acid and glycerol were added, then formed M-silicates were heated at 800 °C. Then, obtained white solid M-Silicates were characterized by Scanning Electron Microscopy (SEM). SEM images show the variance of surface morphology when the temperature increases. The addition of organic compounds is involved in surface modification.

ZnO thin films were prepared on glass substrate by sol-gel spin-coating method using zinc-acetate dihydrate as precursor. Effect of precursor concentration on the morphological and structural of the films was investigated. The diffraction patterns of X-ray diffraction (XRD) characterization indicated that all of ZnO thin films were polycrystalline with a hexagonal wurtzite crystal structure. The peaks were indexed to (100), (002) and (101) planes. Intensity of all diffraction peaks increased and became broader in full width at half maximum (FWHM) values with increasing precursor concentration. The calculation of texture coefficient (TC) indicated that ZnO thin films exhibited the preferential orientation growth along the c-axis. Increasing precursor concentration resulted in decreasing crystalline size and crystallization of the film. The lattice constants (a and c) and d-spacing also changed as function of precursor concentration. It was demonstrated by the bond length, volume per unit cell, lattice strain and dislocation density. The scanning electron microscopy (SEM) images of surface morphology of the films confirmed the results of XRD characterization. The grain size of ZnO thin films decreased as result of increasing precursor concentration. Cross-section of SEM images showed that the thickness of ZnO thin film increases from 149.4 nm to 447.7 nm with increasing precursor concentration. This works shown that morphological and structural of ZnO thin films prepared using sol-gel spin coating methods were strongly influenced by precursor concentration.

Charging a battery in a short time is important for portable devices. Many techniques have been developed to find out the proper method for fast charging. One of those techniques that has been patented in several fast charging methods is pulse current technique. This technique implements pulse current with adjusting pulse wide and voltage threshold in a certain values. In this paper, the capacity fading effects caused by the current pulse in lithium cobalt cells were investigated. The experiment was done by applying pulse current at high-level SOC to charge four cylindrical lithium cobalt cells. The Capacity of each cell was checked every 50 charge-discharge cycles. The experiment result shows that the changing capacity in each cell forms patterns alike. As if there was a slight increament on their capacities at first checking but rapidly decreasing at the next check. Then, their capacities continue to decrease slowly but the more often the charge-discharge cycling, the battery lifetime decreased. This research has provided analysis of pulse current effect on lithium cobalt capacity fading that should be noted as a reference in applying current pulse for fast charging methods.

Nano-composites of TiO₂ and ZnO were successfully prepared using the doctor blade application and high temperature sintering on indium-doped tin oxide (ITO) glass substrate. They were used as efficient photo anode in high performance dye-sensitized solar cells (DSSCs) assembled with N719 dye. The high-density frameworks of TiO₂ and ZnO were synthesized on separate ITO conducting glass using a facile and cost-effective two-step approach to compare the output efficiency. We report on the interfacial boundary relationships, charge – collection conversion efficiency and I-V characteristics of the DSSCs with different electrolytes. The TiO₂ photo anode demonstrated an enhanced solar-to-electrical energy conversion of approximately 5.41 % with KCl electrolyte which was far less than that of a ZnO photo anode with KCl electrolyte which had about 21 % increase under conditions of 1.5 AM. Because of the enhanced solar energy conversion of the ZnO photo anode, l.arboreus with KI sensitizer records 9.78 % is a promising candidate for large manufacture of high performance DSSCs modules.

Mechanical properties of material are largely dictated by constituent microstructure parameters such as dislocation density, lattice microstrain, crystallite size and its distribution. To develop ultra-fine grain alloys such as Oxide Dispersion Strengthened (ODS) alloys, mechanical alloying is crucial step to introduce crystal defects, and refining the crystallite size. In this research the ODS sample powders were mechanically alloyed with different Y₂O₃ concentration respectively of 0.5, 1, 3, and 5 wt%. MA process was conducted with High Energy Milling (HEM) with the ball to powder ratio of 15:1. The vial and the ball were made of alumina, and the milling condition is set 200 r.p.m constant. The ODS powders were investigated by X-Ray Diffractions (XRD), Bragg-Brentano setup of SmartLab Rigaku with 40 KV, and 30 mA, step size using 0.02°, with scanning speed of 4°min^-1. Line Profile Analysis (LPA) of classical Williamson-Hall was carried out, with the aim to investigate the different crystallite size, and microstrain due to the selection of the full wide at half maximum (FWHM) and integral breadth.

We have successfully synthesized silver nanoparticles (AgNPs) by using aqueous extract of papaya (Carica papaya) fruit as bioreductant under sunlight irradiation without additional capping agent. Characterizations were done using UV-Visible spectrophotometry and Fourier Transform Infrared Spectroscopy (FTIR). The synthesized AgNPs have yellowish-brown color with surface plasmon resonance peak at 410 nm. Good selectivity of the AgNPs towards hazardous heavy metal of mercury ions in aqueous solution has been developed as a green environmental sensor. The presence of Hg(II) ions in the mixture changed the yellowish-brown color of AgNPs to colorless due to oxidation of Ag(O) in AgNPs to Ag(I) ions. Effect of samples matrix such as alkali metal, alkaline earth metal and transition metal ions were evaluated.

Lithium bis (oxalato) borate or LiBOB is potential candidate to substitute LiPF₆ which has many problems in lithium ion batteries. Many studies have been synthesized of electrolyte salt LiBOB to improve performance as electrolyte lithium ion batteries. In this paper we have studied the synthesis of compounds LiBOB undergoing pre-heat treatment in a vacuum. LiBOB was synthesized by mixing technical grade raw materials H₂C₂O₄.2H₂O, LiOH and H₃BO₃. The mixture H₂C₂O₄.2H₂O and LiOH was preheated at 60 °C for 2 h before adding H₃BO₃ in several time to be mortared in vacuum dryer, the mixture of the three starting materials was preheated in two steps at 70 °C for 6 h and the third step of preheating at a temperature of 100 °C. This powder was then characterized using XRD, FTIR and BET. The characterization results of LiBOB compared to commercial LiBOB powder. The XRD analysis results showed that the sample have formed LiBOB and LiBOB hydrate phase, while FTIR analysis results show the formation of functional groups of LiBOB. In addition, the BET results shows the surface area of synthesized LiBOB is 75.994 m²/g, close the surface area of commercial LiBOB, i.e 108.776 m²/g.

Antimony-doped Tin Oxide (Sb:SnO₂), shortened as ATO, has become more popular due to their great technological importance. ATO was considered as important transparent conducting material for optoelectronic devices and sensors application because of its unique and special characteristic such as high transparency in visible region, and high electrons concentration and mobility. In this study, the Sb:SnO₂ thin film have been fabricated with low cost and simple ultrasonic spray pyrolysis method. SnO₂ thin film was deposited with three different Sb concentrations namely 1, 2, and 3 wt%. The structural, morphological, optical and electrical properties of this film have been analyzed by using X-ray diffraction, scanning electron microscopy, UV-VIS and four point probe instruments. Based on the optical and electrical properties characterization, the best concentration of Sb doping was 2wt% because its transmittance was above 80% at all wavelength range measured, and the electrical resistivity was quite low, at 0.663 × 10^-3 Ω cm.

Natural zeolite in FeCl₃.6H₂O solution which was exposed with high intensity ultrasonic for 40 min, 80 min and 120 min has been studied. X-Ray Diffraction (XRD) pattern revealed changed pattern and new peaks due to sonication process. Sonication contributed into element composition changes and it had been found also during quantitative chemical microanalysis analysis (EDX) and indicates an increment of 320.81 % (ZAM2) Fe element. Noninvasive back scatter (NIBS) analysis of various ultrasonic times affected to the particle size distribution, surface area and pore analysis. By using density functional theory (DFT), we revealed some improvements such as 44.03% surface area and 67.25% pore radius. We believe that controllable ultrasonic processing in the ferric chloride hexahydrate solution will produce uniform natural zeolite physical and chemical properties as a candidate of adsorbent materials.

The effects of SiO₂-ZrO₂ polymorphic combinations as starting powders and calcination temperature on phase composition of the SiO₂-ZrO₂ composites were studied. Stoichiometric (1:1 mol%) mixtures of the SiO₂-ZrO₂ composites were mechanically activated using a ball-milling for 5 h followed by calcinations at 1000, 1100 and 1200 °C for 3 h. The composites used in the present study were a-SiO₂+ a-ZrO₂, a-SiO₂+ t-ZrO₂, c-SiO₂+ a-ZrO₂ and c-SiO₂+ t-ZrO₂ which were symbolized by AA, AT, CA and CT, respectively. Prefixes a, t and c denote amorphous, tetragonal and cristobalite, respectively. The phase composition was determined by Rietveld analysis of X-ray diffraction (XRD) data using Rietica software. The identified phases for all calcined samples were a combination among t-ZrO₂, c-SiO₂, m-ZrO₂ and zircon (ZrSiO₄). Amorphous zirconia formed a transient tetragonal zirconia phase during heating, which reacted with silica to form zircon. The zircon phase was not found to form even at 1200 °C in the AT and CT mixtures and at 1100 °C in the CA mixture. The AA mixture in particular crystallized to form zircon at a lower temperature with more composition fraction than the others, ca 82.9 (14) mol%.

Pure metals Aluminum (Al), Copper (Cu) and Brass (CuZn) have been detected using laser-induced plasma spectroscopy technique using nanosecond laser. A Q-switch pulsed Nd:YAG laser operating at infrared (1064 nm), visible (532 nm) and ultraviolet (355 nm) wavelengths have been used. The energy laser used was 12 mJ and the experiment was carried out in vacuum condition (5 Torr). The plasma generated by a focused Nd:YAG laser beam was detected by a spectrometer to identify trace elements quantitatively. The result of quantitative trace element of pure metals at three different wavelengths gave the different results. Al metal excited by 355 nm, 532 nm and 1064 nm wavelengths has 5, 2 and 13 Al emission peaks, respectively. Whereas the analysis of Cu showed 5, 7 and 6 emission peaks upon excitation by 355 nm, 532 nm and 1064 nm wavelengths, respectively. Finally, CuZn metal produced 7 Cu lines and 2 Zn lines upon excitation by 355 nm wavelength, 8 Cu lines and 1 Zn line when excited by 532 nm wavelength, and 8 Cu lines and 3 Zn lines when excited by 1064 nm wavelength.

We describe an SMS (single mode - multi mode - single mode) fiber structure to be used in a vibration sensing system. The fiber structure was fabricated by splicing a section (about 300 mm in length) of a step index multi mode fiber between two single mode fibers obtained from a communication grade fiber patchcord. Interference between higher order modes occurs while light from a narrow band light source travels along the multi mode fiber. When the multi mode fiber vibrates, the refractive index profile is changed because of the photo-elastics effect and the amplitude of the interference pattern is changed accordingly. To simulate a vibrating structure we used a loudspeaker to vibrate a wooden table. By using a digital oscilloscope, we recorded and analysed the vibrating signals obtained from the SMS fiber structure as well as from a GS-32CT geophone for referencing. We observed that this SMS fiber structure was potential to be used in a vibration sensing system with a measurement range from 30 to 180 Hz with inherent optical fiber sensor advantages such as light weight, immune to electromagnetic interference, and no electricity in the sensing part.

High sensitivity environmental sensors with a simple and compact structure are required to monitor unwanted pollution such as liquid waste. In this research, a component of environmental sensor based on optical channel waveguide Mach-Zehnder interferometer (MZI) has been designed and also simulated. The materials used in the design were titanium dioxide (TiO₂) as a core and silicon dioxide (SiO₂) with air as cladding. The sensitivity value of the MZI sensor obtained by simulation using computer program was 11 nm/RIU at the angle of 16°. Meanwhile, the obtained fixed length of MZI sensing arm was 4 μm. The proposed design can be used for identifying the existence of liquid material precisely.

This paper discusses the design, construction and characterization of an optical fiber extensometer with heart shape structure. The extensometer was made from a communication grade fiber loop arranged in a housing and pulling mechanism. As the light source, we used 1310 nm LED and a 1325 nm laser diode/LD. To characterize our extensometer, we used a motorized pulling system controlled by a personal computer. From the bending loss characterization using Fujikura fiber as the sensor, we obtained sensitivity of 0.04 dB/mm and measurement range of 28 mm when using the 1310 nm LED, whereas using the 1325 nm LD allowed us to obtain 0.06 dB/mm of sensitivity and 23 mm of measurement range. Using Thorlabs fiber as the sensor, we obtained sensitivity and measurement range of 0.09 dB/mm and 23 mm, respectively, when using the 1310 nm LED. When we used the 1325 nm LD, we obtained sensitivity of 0.03 dB/mm and 31 mm measurement range but with a noted whispering gallery mode/WGM effect. Compromise has to be considered amongst the high sensitivity, measurement range, WGM existence and noise properties to get best data reading for real application.

An extensometer system was developed by using high definition web camera as main sensor to track object position. The developed system applied digital image processing techniques. The image processing was used to measure the change of object position. The position measurement was done in real-time so that the system can directly showed the actual position in both x and y-axis. In this research, the relation between pixel and object position changes had been characterized. The system was tested by moving the target in a range of 20 cm in interval of 1 mm. To verify the long run performance, the stability and linearity of continuous measurements on both x and y-axis, this measurement had been conducted for 83 hours. The results show that this image processing-based extensometer had both good stability and linearity.

Plasmon of gold nanoparticles is one of the hot topics nowadays due to various possible applications. The application is determined by plasmon peak in absorbance spectrum. We have fabricated gold nanoparticles using laser ablation technique and studied the influence of CTAB (Cetyl trimethylammonium bromide) effect on the optical characterization of fabricated gold nanoparticles. We ablated a gold plate using NdYAG pulsed laser at 1064 nm wavelength, 10 Hz pulse frequency at low energy density. We found there are two distinctive plasmon peaks, i.e., primary and secondary peaks, where the secondary peak is the main interests of this work. Our simulation results have revealed that the secondary plasmon peak is affected by random aggregation of gold nanoparticles. Our research leads to good techniques on fabrication of colloidal gold nanoparticles in aqueous solution using laser ablation technique.

Scanning Electron Microscope (SEM) is a proven instrument for analyzing material in which a 2D image of an object is produced. However, the optimization of a 3D image in the SEM system is usually difficult and costly. There is a simple method to produce a 3D image by using two light sources with a red and a blue filter combined in a certain angle. In this experiment, the authors conducted a simulation of the 3D image formation using anaglyph method by finding the optimum point of shifting the red and blue filters in an SEM image. The method used in this experiment was an image processing that employed a digital manipulation on a certain deviation distance of the central point of the main object. The simulation result of an SEM image with a magnification of 5000 times showed an optimal 3D effect that was achieved when the red filter was shifted by 1 μm to the right and the blue filter was shifted by 1 µm to the left from the central position. The result of this simulation can be used to understand better the viewing angle and the optimal position of the two light sources, i.e. red and blue filter pairs. The produced 3D image can be clearly seen using 3D glasses.

This research investigates responses of Optical Fiber Weight in Motion (WIM) sensors when static and dynamic weighing vehicle are applied. The vehicle used in the experiment was a replica of Mitsubishi FE 71 with weight of 23.01 kg. The WIM measurement system consisted of LED 1310 nm, optical fiber based WIM sensor, transimpedance amplified photodetector Ge PDA50 from Thorlabs, data acquisition DT translation 9816 S, speed sensors, and software program for WIM Evaluation. Static weighing was performed when the vehicle stopped. Besides performing static weighing on WIM sensor, measurement was also conducted on Kenko scale as validation. Meanwhile, measurement of dynamic weight was only conducted when the vehicle moved at a constant speed of about 1 km/h through WIM sensor. Experimental results showed two curves corresponded to the front axle load and the rear axle load. During static weighing, both WIM sensor and Kenko scales indicated similar output, which were flat curves. On the other hand, during dynamic weighing, WIM sensor had different output that was a pulse response. This preliminary study resulted in changes of amplitude and output shape. Unlike static weighing, moving vehicles contributed to the output of WIM sensor.

Microcontroller based acquisition and processing unit (MAPU) has been developed to measure vibration signal from fiber optic vibration sensor. The MAPU utilizes a 32-bit ARM microcontroller to perform acquisition and processing of the input signal. The input signal is acquired with 12 bit ADC and processed using FFT method to extract frequency information. Stability of MAPU is characterized by supplying a constant input signal at 500 Hz for 29 hours and shows a stable operation. To characterize the frequency response, input signal is swapped from 20 to 1000 Hz with 20 Hz interval. The characterization result shows that MAPU can detect input signal from 20 to 1000 Hz with minimum signal of 4 mV RMS. The experiment has been set that utilizes the MAPU with singlemode-multimode-singlemode (SMS) fiber optic sensor to detect vibration which is induced by a transducer in a wooden platform. The experimental result indicates that vibration signal from 20 to 600 Hz has been successfully detected. Due to the limitation of the vibration source used in the experiment, vibration signal above 600 Hz is undetected.

This research aimed to develop a vibration sensor based on Fiber Bragg Grating (FBG). The design was mainly done by attaching FBG at the cantilever. The free-end of the cantilever was tied to a vibration source in order to increase the measurement range of vibration frequencies. The results indicated that the developed sensor was capable of detecting wide range of frequencies (i.e. 10 - 1700 Hz). The results also showed both good stability and repeatability. The measured frequency range was 566 times greater than the range obtained from the previous works.

The aim of this research is to figure out an activated zeolite ability to immobilize Pb element in liquid sample. The zeolite was made into powder with size of about 400 μm and was activated by NaOH with different concentrations of 0.5, 1, 1.5 and 2 M. Prior to being analyzed by commercial Laser-Induced Breakdown Spectroscopy (LIBS) technique, 0.05 gram activated zeolite of each concentration were soaked into 10 ml solution containing 100 ppm of Pb and then heated and stirred until become dry powder. The powder was then made into a pellet. After being analyzed by LIBS, activation by 1.0 M NaOH was the optimum condition for zeolite to immobilize Pb in solution. The minimum concentration of Pb in liquid sample which could be immobilized by this method was about 5.86 ppm.

Actually, solar constant is not constant but fluctuated by ±1.5% of their average value. Solar constant indicates that the value is not constant but varies with time. Such variation is correlated with solar activity and cosmic ray. Correlation analysis shows a strong correlation between solar activity and cosmic ray and between solar activity and solar constant. Solar activity indicates by sunspot number. Correlations between solar constant variations and sunspot number variations were found to be higher than ones between variations in cosmic ray and solar constant. It was also found a positive correlation between solar constant and sunspot number, with correlation coefficient about +0.77/month and +0.95/year. In other hand, negative correlation between solar constant and cosmic ray flux i.e. −0.50/month and −0.62/year were found for monthly and yearly data respectively. A similar result was also found for the relationship between solar activity and cosmic ray flux with a negative correlation, i.e. −0.61/month and −0.69/year. When solar activities decrease, the clouds cover rate increase due to secondary ions produced by cosmic rays. The increase in the cloud cover rate causes the decrease in solar constant value and solar radiation on the earth's surface. Solar constant plays an important role in the planning and technical analysis of equipment utilizing solar energy.

Preliminary analysis of lithium in Lithium Iron Phosphate (LiFePO₄) powder using laser induced plasma spectroscopy at low pressure had been done. Recently, LiFePO₄–based batteries are widely used in most electric cars and bikes due to less toxic. However, lithium (Li) element is very difficult to detect since it is a very light element. In this work, we used a Nd:YAG laser (1064 nm wavelength, 5 ns pulse width at 10 Hz repetition rate) that was focused on LiFePO₄ sample at low pressure. The main Li peak emission in LiFePO₄ powder and sheet can be easily detected using this technique. We report the results of experimental study on Li element emission lines at wavelength 460.18 nm, 610.37 nm and 670.83 nm using 2 mJ and 12 mJ laser irradiation at 5 Torr and 35 Torr air atmosphere. The results of this study showed promising application of laser-induced plasma spectroscopy to detect and analyse Li in various samples.

Rhodamine 6G (R6G) or Rhodamine 590 is a cationic dye with a strong absorption in the visible and a high fluorescence yield. R6G is commonly used as a tracer dye in water to determine the rate and direction of flow and transport. Some examples of Rhodamine dye applications are fluorescence microscopy, flow cytometry, fluorescence correlation spectroscopy, etc. In this work, the optical properties of R6G with various concentrations in water were observed by mean of photoluminescence (PL) measurement. The experimental results showed that the higher the concentration, the greater the intensity of the photoluminescence. It is observed that R6G dye emission spectrum had two distinctive peaks, at 550 nm and 602 nm wavelengths. R6G dye concentration affected these peaks in a very interesting manner. With the increasing R6G concentration, the emission peak shifted from 550 nm, which is dominated by monomer, to 602 nm, which is dominated by dimer emission. Our findings have given a good clue in optimizing the concentration of R6G dye in order to give the best emission for various applications.

This paper reports the synthesis of silver colloids by femtosecond laser ablation of ammonia-containing AgNO₃ solution. Effect of ammonia concentration in solution on the production of Ag nanoparticles was discussed. It is found that ammonia rules out significantly to the formation of Ag nanoparticles at which no Ag nanoparticle were formed in the solution without ammonia. Using the solution with the optimum ratio of ammonia to Ag⁺ ions, we further investigate the growth process of Ag nanoparticle by monitoring the evolution of its absorption spectra at 402 nm as a function of irradiation time. The result showed that the growth process was fit to the simple exponential function, and confirmed that the addition of ammonia alone to the metal ion system can boost the particle production by femtosecond laser.

Laser Induced Breakdown Detection (LIBD) is one of the quantification techniques for colloids. There are two ways of detection in LIBD: optical detection and acoustic detection. LIBD is based on the detection of plasma emission due to the interaction between particle and laser beam. In this research, the changing of light intensity during plasma formations was detected by a photodiode sensor. A photo emission data acquisition system was built to collect and transform them into digital counts. The real-time system used data acquisition device National Instrument DAQ 6009 and LABVIEW software. The system has been tested on distilled water and tap water samples. The result showed 99.8% accuracy by using counting technique in comparison to the acoustic detection with sample rate of 10 Hz, thus the acquisition system can be applied as an alternative method to the existing LIBD acquisition system.

The road damage due to excessive load is one of the causes of accidents on the road. A device to measure weight of the passing vehicles needs to be planted in the road structure. Thus, a weight sensor for the passing vehicles is required. In this study, we designed a weight sensor for a static load based on a power loss due to a micro bending on the optical fiber flanked on a board. The following main components are used i.e. LED 1310 nm as a light source, a multimode fiber optic as a transmission media and a power meter for measuring power loss. This works focuses on obtaining a suitable deformer design for weight sensor. Experimental results show that deformer design with 1.5 mm single side has level of accuracy as 4.32% while the design with 1.5 mm double side has level of accuracy as 98.77%. Increasing deformer length to 2.5 mm gives 71.18% level of accuracy for single side, and 76.94% level of accuracy for double side. Micro bending design with 1.5 mm double side has a high sensitivity and it is also capable of measuring load up to 100 kg. The sensor designed has been tested for measuring the weight of motor cycle, and it can be upgraded for measuring heavy vehicles.

Laser-induced breakdown detection (LIBD) is among many techniques utilizing laser beam to characterize nanoparticles in solution. It is based on the detection of plasma formation resulted from the interaction between particles and laser beam. In acoustic LIBD, the acoustic signal which accompanies the plasma formation is detected by a microphone. In this study, a 1064 nm pulsed laser was used as the laser source for LIBD system instead of the frequently used 532 nm. The presence of colloids in filtered and unfiltered water was investigated using the new system and the result was compared with those from conventional system. The S-curves from 1064 nm system showed similar trend with S-curves from 532 nm system. The presence of larger nanoparticles in unfiltered water resulted in lower breakdown threshold energy. However, the breakdown threshold energy of both filtered and unfiltered water was much higher in the 1064 nm LIBD system. The shifting was attributed to the high absorbance of water at 1064 nm. This research proved the possibility of using 1064 nm pulsed Nd:YAG laser as an alternative wavelength source for LIBD system, nevertheless various setup arrangement might be needed.

The bonded magnet NdFeB has been made by using the hot press method and using Poly Vinyl Butiral (PVB) as a binder. The composition of polymeric binder was varied: 0, 2, 4, 6 and 7 % of weight. Both raw materials are weighed and mixed according to the composition of PVB, then formed by hot press with a pressure 30 MPa, a temperature of 160 ° C and holding time for 30 minutes. The bulk density was measured by using Archimedes method. SEM observation was done to determine the microstructure of bonded magnet NdFeB. The flux magnetic value was measured by using a Gauss meter and the measurement of hysteresis curves was done to know value of remanence Br, coercivity Hc and energy product BHmax by using VSM. According to the characterization results show that the best composition of PVB is 2 of weight. The properties of bonded magnet NdFeB of those compositions are the bulk density around 5.66 g/cm³. Flux Magnetic value: 1862 Gauss, Br value: 5000 kGauss, Hc value: 8.49 kOe and BHmax value : 5.10 MGOe. According of SEM observation results show that the polymer matrix of PVB appears to have covered on all surface grain and filled grain boundary.

FeSe is a superconducting material, which has the simplest crystal structure among the Fe-based superconductors. It has no arsenic element, which is very harmful to the human body. In this study, we analyzed the effects of milling time and Te doping on FeSe superconductors. The synthesis of the samples were carried out using powder-in-tube method in a SS304 stainless steel tube. After the pressing process, followed by the sintering process at 500° C for 20 hours, the samples were removed from the tubes. Later, we analyzed its crystal structures, surfaces morphology and the superconductivity properties. Δ-FeSe phase (hexagonal, non-superconductor) and β-FeSe (tetragonal, superconductor) were formed in the samples, including minor phases of Fe and Fe₃Se₄. Te doping changed the crystal structure from β-FeSe and Δ-FeSe into FeSe_0.5Te_0.5. In addition, the onset critical temperature (T_{C, onset}) shifted to higher temperature.

Barium hexaferrite (BaFe₁₂O₁₉) permanent magnets with the addition of Al₂O₃-MnO (0.12, 0.24; and 0.42 wt%) have been prepared by mechanical alloying method. The addition of Al₂O₃-MnO was done in order to improve the density and mechanical properties of the fabricated BaFe₁₂O₁₉ permanent magnet. Particle size of the as-mixed powder decreases Al₂O₃-MnO concentration increases. The as-mixed powders was then compacted into pellets and sintered at 1000 and 1100 °C for 2 hours. The crystalline phases and morphology of the pellets were observed using X-ray diffraction (XRD) and Scanning electron microscopy (SEM), respectively. It is found that the increase of the sample hardness has correlation with the bulk density of the samples. While, the flux density decreases linearly as Al₂O₃- MnO additives increases. The analysis of hysteresis curves classified the pellets as a hard magnet.

Cryogenic equipment is used especially for the research on superconductors as the tools to create a condition of low temperature and high magnetic field. However, it needs the measurement system to be used to analyze the material properties. This work developed a control program of resistance measurement system using instruments of current source, nanovoltmeter and temperature controller. We designed and developed a measurement system by building a connection of the instruments and creating a new control program. The created control program can be revised or modified easily when we have to replace or add the instruments. LabVIEW program was used as a control program, and designed for measuring the resistance and controlling the temperature. Four-point probe method was used to measure the resistance value, a sensor to determine the temperature and a heater to control the temperature. The developed measurement system was tested using standard superconductor sample. It clearly showed the graph of the temperature dependence of resistance. And it showed sharp drop of resistance around 98K, indicating its critical temperature.

The BaFe₁₂O₁₉ magnet has been made at several sintering temperature (1100, 1150, 1200, 1250 and 1300°C) and various additive Na₂O (0, 1, 2 and 3 % of weight) by using Powder Metallurgy. The BaFe₁₂O₁₉ powder and NaHCO₃ powder as Na₂O source were mixed with ethanol until homogeneous by using magnetic stirrer, dried at 80°C and calcined at a temperature 1000 °C for 1 hour. The calcined powders were milled by using a ball mill in dry condition. Then, the powders were mixed with 3 % PVA as a binder, then, the powder is put into a dies mold and pressed with a pressure of 30 MPa. The disc samples were sintered by using furnace Thermolyne. The characterization of the sintered sample was done such as measurement of density and porosity, analysis of crystal structure and measurement of magnetic properties. The characterization results show that the optimum sintering temperature is 1200 °C with additive 1% of Na₂O, if more than 1 %, the physical and magnetic properties decrease. The composition of additive N₂O at the sintering temperature 1200°C does not influence the crystal structure.

Barium Hexaferrite-based permanent magnets (BaFe₁₂O₁₉) was known for its high magnetic anisotropy and suitability in broad applications. Some dopants and atomic substitutions have been utilized to improve its properties for special purposes. In this paper, the Fe-Mn system was used as a dopant for preparing Fe-Mn-doped barium hexaferrite permanent magnet using mechanical alloying method. The physical properties of the samples, such as bulk density, and porosity were examined to study the effect of the dopant. In addition, the crystal structure and magnetic properties of the samples were analyzed using X-Ray Diffractometer (XRD) and Vibrating Sample Magnetometer (VSM), respectively. It is found that the addition of Fe-Mn into barium hexaferrite contributes on the appearance of minor phases such as iron oxide-based magnetite and hematite. In addition, the XRD peak shifted to smaller angle which is likely due to Mn ion substitution and lattice strain within the hexaferrite crystal. It is also observed that the magnetic properties of Fe-Mn-doped barium hexaferrite was inferior to that of the undoped samples. It means that the formation of magnetite and hematite from Fe-Mn dopant during the sintering process is dominant and results to the reduction of hard magnetic properties of the samples.

Coupling of copper oxide (CuO) and zinc oxide (ZnO) was done by chemical precipitation method. In this method, copper sulfate pentahydrate and zinc sulfate heptahydrate salt precursors were separately dissolved in distilled water; then were mixed together. The copper sulfate-zinc sulfate solution was then combined with a sodium hydroxide solution. The precipitates were collected and washed in distilled water and ethanol several times, then filtered and dried. The dried sample was grounded, and then undergone heat treatment. After heating, the sample was grounded again. Zinc oxide powder and copper oxide powder were also fabricated using chemical precipitation method. X-Ray Diffraction measurements of the coupled CuO/ZnO powder showed the presence of CuO and ZnO in the fabricated sample. Furthermore, other peaks shown by XRD were also identified corresponding to copper, copper (II) oxide, copper sulfate and zinc sulfate. Results of the photocatalytic activity investigation show that the sample exhibited superior photocatalytic degradation of methyl orange under visible light illumination compared to copper oxide powder and zinc oxide powder. This may be attributed to the lower energy gap at the copper oxide-zinc oxide interface, compared to zinc oxide, allowing visible light to trigger its photocatalytic activity.

In this study, multiferroic of BiFeO₃ was successfully synthesized using solid state methods. The materials was calcined by variation temperature at 800, 840, 860, and 880°C for 4hours in air atmosphere. Structure analysis and phase transformation were carried out using X-ray diffraction. The results show that not only BiFeO₃ phase is formed but also other phases as secondary phases on all variation temperatures. The secondary phases, i.e. Bi₂₅FeO₄₀ and Bi₂Fe₄O₉, have different molar or weight percentage at that variation. BiFeO₃ has a perovskite structure and considering as R3c space group, for all secondary phases consist of cubic structure. The results showed that increasing calcination temperaturedecrease the amount of BiFeO₃ phases and increase the secondary phases. The highest percentage of BiFeO₃ phases (91.69%) is obtained at 800°C.

Empty fruit bunches of oil palm is a by-product of the palm oil industry that contains a high element of carbon. This by-product can be processed into a conductive carbon paper that could be applied as fuel cell electrodes. Carbon paper for this application must be conductive, porous, and hydrophobic. Utilization of oil palm empty fruit bunches begins with the carbonization process at a temperature of 500°C that produced charcoal. It is followed by heating at temperature of 900°C and 1300°C. To obtain the carbon paper, powdered charcoal with polymer binder (PEG and EVA) were mixed in solvent and molded using tape casting method. This process successfully produced carbon paper with dimensions of ±(20x20) cm² and a thickness of 0.1-0.3 mm. Properties of carbon paper were characterized and analyzed in terms of electrical conductivity, porosity, hydrophobic property, and microstructure. Polytetrafluoroethylene (PTFE), a hydrophobic agent, was treated on carbon paper to enhance the hydrophobicity of the carbon paper. PTFE coating on the surface of the carbon paper could change their physical properties. Carbon paper shows excellent properties in terms of porosity and hydrophobicity. Whereas, its electrical property needs to be improved further by increasing the pyrolysis temperature. But overall, this might show a potential GDL material for PEMFC.

Since Bauxite has been widely used in industry and in scientific investigations for producing Aluminum, it is important to measure the radionuclides concentrations to determine the health effect. The Bauxite mine is located in Az Zabirah city in Saudi Arabia. The concentrations of the radionuclides in the bauxite samples were measured using γ-ray spectrometer NaI (Tl). The average and range values of the concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were 102.2 (141.1-62.7), 156.3 (202.8-102.8) and 116.8 (191.7- 48.9) Bq/kg respectively. These results were compared with the reported ranges in the literature from other locations around the world. The radiation hazard parameters; radium equivalent activity, annual dose, external hazard were also calculated and compared with the recommended levels by International Commission on Radiological Protection (ICRP-60) and united nations scientific committee on the effects of atomic radiation UNSCEAR reports. There are no studies for the natural radioactivity in the bauxite mine in Az Zabirah city, so these results are a start to establishing a database in this location.

Magnesium and its alloys is a promising candidate for implant application especially due to its biodegradability. In this study, Mg-7Ca alloys (in weight %) were processed by powder metallurgy from pure magnesium powder and calcium granule. Milling process was done in a shaker mill using stainless steel balls in various milling time (3, 5, and 8 hours) followed by compaction and sintering process. Different sintering temperatures were used (450°C and 550°C) to examine the effect of sintering temperature on mechanical properties and corrosion resistance. Microstructure evaluation was characterized by X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. Mechanical properties and corrosion behavior were examined through hardness testing and electrochemical testing in Hank's solution (simulation body fluid). In this report, a prolonged milling time reduced particle size and later affected mechanical properties of Mg alloy. Meanwhile, the phase analysis showed that α Mg, Mg₂Ca, MgO phases were formed after the sintering process. Further, this study showed that Mg-Ca alloy with different powder metallurgy process would have different corrosion rate although there were no difference of Ca content in the alloy.

Limonite ore from Sulawesi Island (Indonesia) was reduced isothermally at 900 – 1200°C by pulverized coal and charcoal to produce ferronickel. XRD and XRF analyses were used to characterize the samples. The influence of reductive conditions on the reduction and metallization degree of the samples, including reduction temperature, reduction time and reducing agent types were studied. Results have shown that both the reduction and metallization degrees increase as temperature and time increase. The reduction reactions will be more completed at higher reduction temperature. It could be seen from XRD results that magnetite and Fe-Ni peaks increased at higher temperature reduction. This could be mean that the rate of reduction reaction is faster at higher temperature. The losses of samples weight also happen faster at higher temperature. It was also found that the reduction behaviors using coal differed from those using wood charcoal due to the differences in proximate content. From this study, it could be concluded that fixed carbon content in the reducing agent did not always be the most important aspect of choosing a reducing agent. The sample which has been reduced with coal and charcoal showed an almost exactly same pattern even they both had different characteristics. The relatively higher volatile matter content in charcoal gave a significant contribution to the reduction process.

The purpose of this research was to purify cassiterite from associated minerals (impurities) and to investigate the effects of pretreatment on the dissolution of impurities from Indonesian cassiterite mineral. The steps of this research are as follows: characterization, pretreatment and leaching processes by dilute hydrochloric acid (HCl) solution. Firstly, cassiterite was characterized by X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) techniques, and then pretreatments were carried out including washing, roasting at 700 °C and both combinations of washing and roasting at 700°C. Cassiterite obtained from the processes of pretreatment and without pretreatment was then leached using 10% HCl solution with temperature variations of 35 °C – 150 °C for 2 hours in atmospheric condition. The results showed that the chemistry composition of cassiterite was as follows: 57.82% Sn, 0.45% Si, 1.45% Ti, 1.79% Fe, 3.43% La, 3.37% Ce and 31.69 % others. The best condition for purification of cassiterite was leaching without pretreatment that has the highest dissolution of associated mineral from cassiterite than other processes (pretreatment) for leaching at 110 °C for 2 hours. This research was able to purify cassiterite with a chemical composition as follows: 66.14% Sn, 0.27% Si, 1.38% Ti, 1.18% Fe, 2.12% La, 2.03% Ce and 26.88% others. These results are quite satisfactory because this technology is quite simple and economical.

The performance and kinetic of nickel laterite reduction were studied. In this work, the reduction of nickel laterite ores by anthracite coal, representing the high-grade carbon content matter, and lamtoro charcoal, representing the bioreductor, were conducted in air and CO₂ atmosphere, within the temperature ranged from 800°C and 1000°C. XRD analysis was applied to observe the performance of anthracite and lamtoro as a reductor. Two models were applied, sphere particle geometry model and Ginstling-Brounhstein diffusion model, to study the kinetic parameters. The results indicated that the type of reductant and the reduction atmosphere used greatly influence the kinetic parameters. The obtained values of activation energy vary in the range of 13.42-18.12 kcal/mol.

Austenitic manganese steel is steel alloy that has high manganese content (10-14%wt Mn). The characteristics of austenitic manganese steel are good in toughness, ductility, and wear resistance. Effect of solid solution treatment on the hardness and microstructure of austenitic manganese steel was studied in this experiment. The solid solution treatment process of austenitic manganese steel, 0.6%wt C-10.8%wt Mn-1.44%wt Cr, was conducted by heating the material at varied temperatures (950°C, 1000°C, 1050°C) for an hour and then quenching it in two different quenching media, i.e. oil and water. Further, the samples were tempered at three different temperatures (300°C, 400°C, and 500°C) for 2 hours. The treated materials were analyzed by Rockwell Hardness Tester to obtain the information of materials hardness and by an optical microscope and XRD to investigate the microstructure phase of the treated materials. Heating the austenitic manganese steel at 950°C for an hour followed by water quenching dissolved all carbide in as-cast condition and resulted the fully austenitic on its microstructure. Carbide precipitation occurred due to the prolongation of soaking time in solid solution treatment and tempering process. The optimum hardness of sample was 53.3 HRC, which was resulted by heating this material until 1000°C for an hour, followed by water quenching and tempering at 400°C for 2 hours.

Intermetalic coatings of NiCoCrAl have been successfully developed on low carbon steel substrate to improve oxidation resistance in extreme environments. The influence of oxidation temperature on the oxide scale formation was studied in the temperature range of 600-1000 °C. The measurements were made in air under isothermal oxidation test for 100 h. The surface morphology showed that a cauliflower like structure developed entire the oxide scale of sample oxidized at 800 °C and 1000 °C, while partly distributed on the surface of sample oxidized at 600 °C. The XRD analysis identified Cr₂O₃ phase predominantly formed on the oxidized sample at 600 °C and meta-stable Al₂O₃ with several polymorphs crystalline structures: η, δ, θ, κ, and α-Al₂O₃ at relatively high temperatures, i.e. 800 °C and 1000 °C. A Cross-sectional microstructure showed that complex and porous structures formed on the top surface of 600 °C and 1000 °C samples. In contrast, a very thin oxide scale formed on 800 °C oxidized samples and it appeared to act as a diffusion barrier of oxygen to diffuse inward, hence could increase in the service life of carbon steel substrate.

Antifouling paints were applied on a wide range of the under seawater structures in order to protect them from the growth of fouling organisms. The performance investigation of two commercial anticorrosion and antifouling paints was conducted in Muara Baru port, Jakarta. The specimens were coated by anticorrosion and/or antifouling paint. Blank specimen (without exposed) were also prepared as a control. On the other hand, bare mild steel was prepared for measure the corrosion rate through weight loss method. The test panels containing specimens were exposed up to 3 months for immersion depths of 0, 1, 2, 3 meters from sea level. Sea water parameters such as temperature, pH, salinity, conductivity and dissolved oxygen (DO) were also measured. The evaluation of coating performance was carried out such as thickness, glossy, hardness and adhesion strength. The results showed that both surfaces of anticorrosion paint and bare mild steel specimen covered by fouling organisms, whereas no fouling took place on the surface of antifouling paint. The corrosion rate of bare mild steel in the depths of 0, 1, 2, 3 meters were 12.5; 11.6; 8.3; 10.4 mpy, respectively.

Non-thermal plasma has become one of the new technologies which are highly developed now days. This happens because the cold plasma using the principle of generated reactive gases that have the ability to modify the surface properties of a material or product without changing the original characteristics of the material. The purpose of this study is to develop a cold plasma system that operates at atmospheric pressure and investigates the effect of cold plasma treatment to change the surface characteristics of the polymer material polyethylene (PE) at various time conditions. We are successfully developing a non-thermal plasma system that can operate at atmospheric pressure and can be run with Helium or Argon gas. The characteristics of plasma will be discussed from the view of its electrical property, plasma discharge regime andoperation temperature. Experiment results on plasma treatment on PE material shows the changes of surface properties of originally hydrophobic material PE becomes hydrophilic by only few seconds of plasma treatment and level of hydrophilicity become greater with increasing duration of plasma treatment. Confirmation of this is shown by the measurement of contact angle of droplets of water on the surface of PE are getting smaller.

The low oxidation pressure behavior of binary FeAl alloys has been examined at different temperatures of 600-700°C. Polycrystalline and single-crystalline samples of Fe-10Al and Fe-25Al were oxidized for 1 h at 10-6 mbar of oxygen in an ultra-high-vacuum chamber (UHV). Prior oxidation, samples were prepared by sputter-annealing cycles in UHV. After oxidation, the samples were analyzed by X-ray Photoelectron Spectroscopy (XPS). The formed oxide layers on the surfaces consist of FeAl₂O₄ and Al₂O₃ showing that Al has a dominating role during the oxidation process. From XPS peaks, the composition of the Fe peaks of the oxide layer consists of Fe metal, FeAl-alloys, and FeO. Meanwhile, the composition of the Al peak is changed from Al metal, FeAl-alloys and Al₂O₃ at 600°C to Al metal, FeAl-alloys and FeAl₂O₄ on 700°C. From XPS sputter depth profiles, it is shown that the oxide layer was growing with increasing temperature, and the single-crystalline Fe-10Al has a thicker formed oxide layer than poly-crystalline Fe-25Al with same oxidation treatment.

In the present study, varying composition of FeB-Al was coated on low carbon steel by using mechanical alloying technique for 4 hours and followed by heat treatment in vacuum atmosphere of 5.9 Pa at 700 °C. The microstructure and formed phases of FeB-50 at.%Al, FeB-25 at.%Al, FeB-12.5 at.%Al and FeB coatings were intensively discussed. The cross sectional observation indicates that the coating thickness tends to increase with increasing Al content. Before heat treatment, the coatings are composed of FeB and Al phases, depending on coating composition.. After heat treatment, the intermetallic phases were identified. Interdifussion layer was also formed in the FeB-50 at.%Al coating after heat treatment.

The subsurface structure of the Sembalun-Propok area, NTB, Indonesia, has been investigated using magnetotelluric method (MT). To obtain the information of the dimensionality of the regional structure and determine the regional strike of the study area, the phase tensor analysis has been performed in this study. The results show that most of the skew angle values (β) are distributed within ± 5°. It indicates that the regional structure of the study area can be assumed as two dimensional. In addition, to determine the regional strike of the study area, we also calculated the major axes of the phase tensor. The result presents that the regional strike of the study area is about N330°E. According to the results of the phase tensor analysis, we rotated the impedance tensor to N330°E and performed 2-D inversion modeling. The result presents that the substructure model suits with the geological background of the study area.

There are at least five climate-drivers influencing temporal variability of the Indonesian precipitation system, namely the diurnal cycle, the Madden-Julian Oscillation (MJO), the monsoon system, the Indian Ocean Dipole (IOD), and the El Niño–Southern Oscillation (ENSO). In particular, the IOD and the ENSO events will cause interannual variations in the Indonesian precipitation. During the positive IOD or the El Niño events, Indonesia experiences a severe drought event. On the other hand, during the negative IOD or the La Niña event, Indonesian will have excess precipitation. During 2014, most part of the Indonesian regions experience deficit precipitation leading to a severe drought event. This study is designed to evaluate the dynamics underlying the extreme climate event in 2014. Several climate indices, including the sea surface temperature (SST), outgoing long-wave radiation, and surface winds were evaluated to explain why Indonesia experience severe drought in 2014. The analysis indicates that the tropical Indo-Pacific climate modes (e.g. IOD and ENSO events) were in neutral conditions. It is, then, suggested that negative sea surface temperature anomalies in the Indonesian region, in particular in the eastern part suppressed convective activities leading to deficit precipitation over the maritime continent.

The Cimandiri fault zone is located in the eastern part of the boundary between the oblique subduction of the Indo-Australian plate along Sumatera and the frontal subduction along Java. Even though some geological and geophysical investigations have been conducted and focused on this area, the geometry of the fault zone remains poorly resolved. To provide better constraints on the geometry of the Cimandiri fault zone, we analyze teleseismic receiver functions from single permanent seismic station located in the fault zone. We observe that the computed receiver functions show back azimuthal variation in the amplitude converted waves at the first 2 second of receiver functions providing clear evidence for the presence of complicated shallow structure. We implement forward modelling technique using synthetic seismograms with the same parameters as the observed receiver functions. The modelling reveals at least 2 km thick low velocity zone dipping N-E at 30°, which might be correlated to the Cimandiri fault.

We present a preliminary result of crustal thickness in Northern Sumatra from receiver function analysis and grid search. Total of 111 teleseismic events from three broadband stations (TPTI, KCSI, and BSI) of IA-Network were used to calculate the receiver functions. We identified direct P and S arrival from the receiver function. Converted phases Ps were relatively clear for all three broadband stations. Ps-P time was estimated about 2 - 3 s, 2 s, and 5 - 6 s for station TPTI, KCSI, and BSI, respectively. We applied H-k stacking method to obtain crustal thickness and Vp/Vs ratio beneath the three broadband stations. At station TPTI, we obtained the crustal thickness is about 19.54 ± 3.84 km, Vp/Vs ratio is about 1.73 ± 0.14. At station KCSI, the crustal thickness was estimated to be 37.07 ± 4.47 km, Vp/Vs ratio is about 1.84 ± 0.10. At station BSI, which is located to the north of these two stations, the crustal thickness was estimated to be 40.56 ± 2.26 km, Vp/Vs ratio is about 1.81 ± 0.05. These results show relatively large variation of crustal thickness in the Northern Sumatra.