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Ferromagnetic minerals make up only a small volume of a rock or sediment, but provide information on the geochemical conditions when a rock is formed and on environmental conditions that will dictate preservation or alteration over geological time. A number of techniques, which help identify the composition, concentration and particle size of the ferromagnetic minerals, have been developed over the past 80 years. These methods are also applicable in the characterization of magnetic nanoparticles, whose synthesis has become a major global industry with a range of applications. Magnetic methods provide information that can be used to assess performance for an application and long-term chemical stability. It is important to understand the long-term fate of these particles with respect to biomedical applications that use magnetic nanoparticles in magnetic and particle resonance imaging, drug delivery systems, and hyperthermia treatment of tumors. The focus of this presentation is to show how magnetic techniques can be used in the material, life and environmental sciences. [ABSTRACT FROM AUTHOR]

Magnetic susceptibility is a magnetic vulnerability that is often measured in rocks for various purposes. In this study, magnetic susceptibility was applied to distinguish weathering in rocks in different environments i.e., beaches and mountains. The rocks used are igneous rocks originating from Sikambe mount and rocks on the Prigi Coast in Trenggalek Regency. The samples were taken in three categories, i.e., are Fresh, semi weathered, and perfectly weathered rocks. All the rock was crushed to form like gravel, then tested magnetic susceptibility (χlf and χhf). It is shown that the magnetic susceptibility value of the mount Sikambe area in fresh rocks is higher than that of perfectly weathered rocks, while in the coastal area, Prigi has the magnetic susceptibility value of weathered rocks is greater than fresh rocks. The values of χlf and χhf can be calculated the value of frequency-dependent susceptibility (χfd). The average value of χfd in Sikambe mount is indicating that magnetic mineral grains are in the range of multi-domains (MD), and on the coast of Prigi is indicating that magnetic mineral grains are in the range of pseudo-single domains (PSD). In this case, χfd, can be useful to knowing the level of rock weathering. [ABSTRACT FROM AUTHOR]

The monitoring found the seepage at the wall canal at downstream foothill in the Selorejo dam. It is a sign that there is water leakage from the dam. To better understand the path of leakage water, some locations of the dam were scanned using 90 MHz radar. The scanning location was done at three locations, namely at (1) the top, (2) the middle slope downstream hill, and (3) the downstream foothill dam using profiling. All those locations were scanned using the B-scan technique. The methods of analysis employed in this research were a gain profile, bandpass filter, and average subtraction to see the radargram clearly. The results found that there are two paths of seepage that started from the top dam. This path shows clearly at the middle slope dam, and this path is unified along before foothill downstream. It implies that seepage might be an early stage of the internal erosion process. [ABSTRACT FROM AUTHOR]

In general, carbon is abundantly available in the form of biomaterials derived from plants, either as bio-products or bio-waste. In this study, we investigated carbon characteristics of corncob powders, which were synthesized using a coprecipitation method and heated at 400 °C. The samples were analyzed using thermogravimetric analysis (TGA), X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR). The results of this study indicated that samples heated at 100 °C encompass a crystalline phase, while samples heated at 400 °C formed an amorphous phase. Morphology of all samples was formed in a micrometer size in the form of lumps with the highest carbon content of 72.3%. The C=C functional group in the carbonated samples at 400 °C was detected at a wavenumber of 1593 cm-1, which is a characteristic of carbon in graphite and graphene. [ABSTRACT FROM AUTHOR]

Dam core conditions are important to check its safety regularly. One way to determine the condition of a dam is to compare the pore-water pressure upstream to downstream. If the upstream pore-water pressure is higher than downstream, the dam is in good condition. The pore-water pressure at the dam is got from the piezometer planted inside the dam. If the piezometer is damaged, the condition of the dam's core is unknown. In Lahor dam there are 18 piezometers, but only one was functioning. The pore water pressure of the piezometer is determined by the height of the water column above it so that if the water level is known in the dam core, the pore water pressure will be known. To find out the water table, georadar can be used using a B-scan survey technique along the Lahor dam. The radargram is then processed to get the type of material by finding the wave velocity regarding the water level at the upstream of the dam. The water table is obtained from reflections of anomalous material differences. The water table converted into pressure based on piezometer level. From the results of pore water pressure in upstream and downstream, it can be concluded that the Lahor dam is in good condition. [ABSTRACT FROM AUTHOR]

A novel PVA/TiO2 nanofibers composite membranes that can be used for photocatalytic applications are synthesized by electrospinning methods. These new nanofibers membranes are prepared by better processing of the electrospun solution with the addition of sonication and surfactants. PVA/TiO2 composite nanofibers were observed by the characterization of SEM, EDAX, and FTIR. The characterization results showed the PVA/TiO2 composite nanofibers membranes have a good performance of photocatalytic. FTIR results showed functional PVA groups, and EDAX results showed TiO2 successfully inserted into the nanofibers membrane. The effects of processing with certain treatments, such as sonication and surfactant addition to the morphology and photocatalytic properties, were studied in the experiment. EDAX characterization shows that nanofibers with sonication have a TiO2 distribution along with an increase in the percentage of TiO2 up to 10.20%. This indicates that sonication can increase the electrospun solution to be more homogeneous. Nanofibers, with the addition of surfactants, have better TiO2 distribution, along with an increase in the percentage of TiO2 to 16.21%. The dye degradation ability of the PVA/TiO2 composite nanofibre membrane was investigated by the methylene blue photodegradation test under UV light. Methylene blue degradation was measured by UV vis spectroscopy. The photocatalytic activity of the PVA/TiO2 composite nanofibre membrane reduced Methylene Blue up to 40%. Sonication treatment increases photocatalytic activity by up to 60%, and the addition of surfactants increases photocatalytic activity by up to 80%. [ABSTRACT FROM AUTHOR]

The synthesis of barium hexaferrite M-type with (BaFe12ZnMnO19) doped Zn-Mn ion can be applicated as an absorbent of the microwave by the co-precipitation technique. This study to tracing the influence of doping ion was synthesis varied at concentration doping (x = 0.0, 0.6 and 1.0) and temperature maturation 80, 600, and 800 °C on properties of the electrical sample. The samples were characterized by analysis using Network Vector Analyzer (VNA). The result from VNA gets data of conductivity of electrical values at range 8.0 to 15.0 GHz. It is showed that the sample is a semiconductor (5.8 × 10−4 - 1.27 × 10−1 S/cm). The value of permittivity real and imaginary showed that increased with increasing concentration doping and frequency. [ABSTRACT FROM AUTHOR]

A noise that recorded at magnetotelluric acquisition data makes the data quality not good enough, so the information obtained after data processing might not be correct or not suitable for the subsurface condition. Several characters of noisy magnetotelluric data are the spiky shaped and non-stationarity time-series curves. This non-stationarity character can't be handled by the Fourier Transformation process. This research used Empirical Mode Decomposition (EMD) in the original of Huang as a filtering method in order to overcome the non-stationarity. This method decomposed the signal into a group of oscillation mode called Intrinsic Mode Decomposition (IMF). It is one of the best IMF chosen as the filtering result by spectrum analysis in the frequency domain. This work used magnetotelluric data from a station that had three components with different frequency sampling, which was 15 Hz, 150 Hz, and 2400 Hz. IMF filtering method then applied to the data resulting in a smoother times-series curve with the suppressed non-stationarity character. This research showed that EMD filtering can be implemented at magnetotelluric data processing and emphasized the effect caused by noise. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the magnetic properties of weathered and unweathered rocks of basalt and basaltic andesite by measuring magnetic susceptibility and analysis of magnetic domain distribution. The identification of magnetic rock properties by magnetic susceptibility has been done on rock weathering of rip rap in Lahor Dam, Malang regency. Samples were tested using Bartington Magnetic Susceptibility Meter (MS2B) to determine the value of magnetic susceptibility. The result of susceptibility test shows that low-frequency susceptibility (χlf) of the outer part of the potentially weathered rock has values ranged from (314-2,744) × 10−8m3kg−1 for basalt with average 1,470.38 × 10−8m3kg−1, and the inner part (296-2,681) × 10−8m3kg−1, with average 828.85 × 10−8m3kg−1. The average of dependent frequency susceptibility (χfd) for this rock is about 0.767%. Meanwhile for the outer part of basaltic andesite has low-frequency susceptibility (χlf) ranged from (529-3,974) × 10−8m3kg−1, with average 2,241.23 × 10−8m3kg−1, and the inner part ranged from (540-3,754) × 10-8m3kg-1, with average 2,336.11 × 10-8m3kg-1. The average of dependent frequency susceptibility (χfd) for this rock is about 1.018%. Thus, it can be concluded that the magnetic susceptibility of the outer part of the rock is higher than that of the inner part. There are no differences in magnetic domain distribution between the inner and outer parts of rock during the weathering process, and all the samples have a tendency to multi-domain magnetic grains (MD). [ABSTRACT FROM AUTHOR]

As a natural material, iron oxides can be applied and advanced across disciplines, such as industrial, medical, and technological fields. Among various kinds of iron oxides material, there is hematite. In this research, Zn doping on hematite has been successfully executed through a co-precipitation method. Mass variation (0.1 and 0.3 g) was also completed to construe the hematite characteristics through sample characterization using X-Ray Diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, Magneto-thermal instrument, and antimicrobial bacteria testing. Those tests were conducted to 1) see the structural pattern, particle size, and the effect of Zn doping on the crystal structure of the sample, 2) know the functional group of the sample, 3) know the thermal pattern, and 4) see the thermal-activity of the sample. By using XRD data analysis, 5 and 60 nm grains sized of ZnxFe2-xO3 nanoparticles were obtained for Zn mass of 0.1 and 0.3 g, respectively. The result of the magneto-thermal test exhibited a specific absorption rate (SAR) of 1.017 and 1.075 W/g for 0.1 and 0.3 g Zn, respectively. Besides, there was a stronger zone of inhibition of ZnxFe2-xO3 particle with 0.1 and 0.3 g Zn doping applied over E. Coli (∼ 13 and 10 mm) rather than applied to S. Aureus (∼ 7 and 6 mm). Thus, hematite with Zn doping has a potential as the candidate for anti-bacterial agents, particularly for the 0.1 g Zn doping composition. [ABSTRACT FROM AUTHOR]

The neutron star accretes in a binary system. Accretion is hypothesized to cause a magnetic field to decrease in a neutron star. Equation dynamics of neutron star magnetic fields are needed to formulate the relativistic Maxwell equations. Magnetic field dynamic equations are differential equations that require solutions for each radial, polar and azimuthal component. Maxwell's equation has a solution that is assumed to be a bipolar magnetic field. The equation obtained is the equation of the dynamics of the magnetic field in the ZAMO (Zero Angular Momentum Observers) framework by assuming the neutron star is a rapidly rotating and accreting neutron star. This equation corresponds to the slowly rotating neutron star. [ABSTRACT FROM AUTHOR]

Study of complex compounds structures of zinc(II) chloride and cadmium(II) chloride with potassium cyanide and N,N'-diethylthiourea (detu) as compound A and B, respectively, have not been reported. Therefore, the synthesize of those complex compounds had been carried out to study their structure prediction. In this research, compounds A and B were prepared by means of the direct method using distilled-water and methanol solvent. The melting point measurement of compounds A and B gave 203-205 °C and 210-213 °C at ambient pressure, respectively. Structure prediction and free energy calculation of the A and B complexes used Semi-Empirical PM6. Both complexes gave the calculated free energy as -129.605 kJ/mol and -381.0029 kJ/mol with tetrahedral geometry of metal ion, respectively. The electric conductivity test proposed that compound A is ionic, while compound B is molecular. The atomic ratio between the central atom and sulfur as atom donor regarding the EDX analysis for both compounds was 1:4 and 1:1, respectively. The prediction on chemical formula of A was [Zn(detu)4](CN)2 and B was [(CN)(detu)Cd(µ−CN)2Cd(CN) (detu)]. [ABSTRACT FROM AUTHOR]

A thermomagnetic analysis is a study of how a material reacts to the change in temperature. The analysis is conducted by cooling and/or heating the material and observing the change of magnetic moment. Through this observation, the Curie Temperature of a material can be obtained. This Curie Temperature is used to estimate the magnetic minerals contained in samples e.g., rocks, sediments, soils. This paper introduces THERMITS, a MATLAB code for analyzing the thermomagnetic data, which aims to replicate as well as make improvements on existing thermomagnetic analysis tools in MATLAB environment. This MATLAB code will generate three plots, which are thermomagnetic data (magnetic moment vs. temperature), 1st derivative, and 2nd derivative. These derivatives are generated in order to estimate the Curie temperature. The estimation is done by finding the highest value of the 2nd derivative curve which represents the maximum curvature of thermomagnetic data. To improve the accuracy of Curie temperature estimation, this code also provides a smoothing and estimation boundary. Smoothing is important to reduce the variability of the derivative curve so that the Curie temperature can be estimated correctly. Meanwhile, estimation boundary is needed to bound the estimation so that it will not conclude the outer boundary for the estimation; which often has instable data caused by the instrument error. [ABSTRACT FROM AUTHOR]

Applications of quadcopter or hexacopter have helped many scientists and engineers find lots of easiness for survey purposes, particularly in terms of accelerating data collection with high accuracy. For the unmanned aerial vehicles (UAV) to be performing that kind of superior characteristic, direct-current brushless motor plays a very crucial role. In commercial UAV, the brushless motor obtains electric current from lithium-polymer batteries after being handled by an electronic speed controller. Despite the fact that the position of the motor is already sensed, the electric current response in the brushless motor due to applied voltage is also important to detect. This very-careful electric current detection will provide flight controller more detail information regarding the brushless motor performance. In this present study, a Hall- effect based non-contact sensor SS49E form measuring the electric current is introduced. Taking into consideration that small fluctuations of the electric signals sometimes cannot be detected by the Hall sensor, we then increased the magnetic flux by means of inserting half-circular toroids. Our experiment revealed that the approach was effective in such a way that almost all electric signals can be then recorded by the sensor. In addition, the phase modulation and speed-controlled data collection and analysis provided fundamental information that can be used by the flight controller for the more complete algorithm to increase the UAV performance. [ABSTRACT FROM AUTHOR]

In this study, we report green synthesis of Fe3O4 nanoparticles based on biosurfactant Saccharum officinarum extract using sonochemical method. The phase purity of the sample was characterized using an X-ray diffractometer (XRD). Based on the XRD characterization, the addition of biosurfactant S. officinarum did not alter the inverse spinel cubic of Fe3O4 nanoparticles. Quantitatively, the crystallite size was calculated using the Debye-Scherrer equation, resulted crystallite size of 11 nm. The functional groups of the Fe3O4 nanoparticles based on the biosurfactant S. officinarum were also investigated through Fourier-transform infrared (FTIR) characterization. Based on the FTIR data analysis, the presence of Fe3O4 was indicated by the presence of Fe-O bonds at 573 cm-1. Other bonds such as O-H that showed the presence of intramolecular hydrogen bonds from cellulose and S. officinarum were also found at wavenumbers of 3280-3533 cm−1. Furthermore, the presence of the surfactant S. officinarum extract was also found at a wavenumber of 1054 cm−1. It represented the presence of C-O-C bonds from the glycosidic ether band. Therefore, it can be inferred that the utilization of biosurfactant S. officinarum extract has been successfully carried out in the synthesis of Fe3O4 nanoparticles. [ABSTRACT FROM AUTHOR]

This research investigated the alleged existence of potential landslides in front of the Kambal-Mulyorejo Highway section Ngantang District Malang Regency. The purposes of this research determined the subsurface geological structure in front of Highway Kambal – Mulyorejo, Ngantang subdistrict of Malang Regency, and to find out the potential landslides in this area. This research utilizes the Wenner configuration of the geoelectric resistivity method. Measurement was taken in 3 tracks with two tracks in the vertical direction and one track in the horizontal direction. Every track has 200 m with a space of electrode 10 m. Transition resistivity values use Res2dinV software that can provide 2D information from the color that can explain values from each layer resistivity. The three layers have one thing in common, namely the presence of a clay layer with a range of resistivity values of 1.74– 26.1 Ωm. Suspected on the first and third track, there is a slip plane. Because it was found that there's a layer that easily absorbs water but doesn't escape the water, so it will easily collapse when on a slope. In addition, this layer also follows the slope, so it was thought to be a slip plane. Meanwhile, in the second track, it was suspected that slip planes in there, this occurs because the waterproof layer tends to be flat and not tilted following the slope. [ABSTRACT FROM AUTHOR]

Isothermal Remanent Magnetization (IRM) is a method used to observe the magnetization of materials by applying DC magnetic field at a constant temperature. The observed value of magnetization is used to distinguish the magnetic minerals contained in samples e.g., rocks, sediments, soils. This paper proposes IRMITS, a novel MATLAB program for analyzing the acquired IRM data set. This program uses several integrated approaches to analyze each mineral called Linear Acquisition Plot (LAP), Gradient of Acquisition Plot (GAP), and Standardised Acquisition Plot (SAP). In order to be able to analyze the data on a broader range, we provide LAP, GAP, and SAP on semilog axes. The x-axis represents the applied magnetic field on a logarithmic scale, while the y-axis illustrates linear-scaled IRM value. The LAP values normalize IRM values, which is done automatically by this program. The GAP values are obtained through the differentiation of the normalized IRM values. SAP values are found by converting the normalized IRM values into z-score values and probability distribution. Then the generated values of those functions are plotted to get the curves that could be interpreted. Plots from LAP, GAP, and SAP can complement each other in the analysis process. After plotting the results and analyzing the trends of the graphs, different minerals can be distinguished. This is possible because different trends represent different minerals. For further research, analyzed data from this paper could be used to determine the saturation point of minerals and discover different types of composing minerals. Our program can also be used as a quick look to be validated in the future with other methods such as X-Ray Diffraction (XRD) analysis. [ABSTRACT FROM AUTHOR]

As excellent alternatives for cleaner energy production evaluated against conventional nonrenewable energy sources, fuel-cells have now been commercially viable. However, efforts to improve their efficiency are always important. By high temperature and sandwich model of fuel-cells, sealing materials play an important role to prevent air leakage and entirely lock the hydrogen inside to achieve high efficiency. In this study, we reported the phase stability of purified silica- sand/alumina composites under heat cycling treatment within the fuel-cells working temperatures. The composites, containing commercial Al2O3 and purified SiO2 from Indonesian silica sand, were prepared using a simple solid-state reaction approach. X-ray diffraction data collection and evaluation were performed to check the phase formation of the compact ceramic composites. Herein, we focused on the composites' phase stability under heat treatment for several times. As a result, the phase content in the composites remained unchanged. This stable characteristic also applied to the density- porosity behaviors and the coefficient of thermal expansion (CTE) of the composites. In addition, the CTE of the composites was evaluated theoretically and experimentally. Both results agreed that the CTE values of the composites are suitable for sealing materials. From the crystalline structures, physical and thermomechanical stabilities, it is therefore concluded that the silica-sand/alumina composites can be proposed as fuel-cell seal materials. [ABSTRACT FROM AUTHOR]

Pollution hazards can be overcome by knowing the pollution status of the location. Minerals of Fe are most found in sediments. We used to monitor and assess of Fe using microwave optimized BCR. In an optimized leaching process, the variations of the size of the sediment particles, pH, and concentration of solvents in the oxidation fraction were analyzed to find the maximum assessment. The samples were tested by XRD and then leached Fe by optimized microwave BCR method to apply of 100 and 200 mesh of sample-accurate and precision. Fe concentration in sediments was recorded of 200 mesh more higher comparing those in 100 mesh. Concentrations of 0.5 M NH2OH.HCl with pH 1.5 was 1.5 times higher compared to other treated concentrations. The amount of Fe in the location of the Pasir Putih was still below the threshold, indicating no pollution in the waters of Pasir Putih Beach. [ABSTRACT FROM AUTHOR]

This work presents a study of synthesis and characterization, as well as the application of adsorption from amorphous SiO2. The synthesis method used is a continuous method (hydrothermal-coprecipitation), from natural silica sand. The results of XRD and FTIR characterization prove that the synthesized SiO2 powder has an amorphous phase structure; and morphological analysis results showed a particle size of about 80 nm, spherical morphology, and BET data proved to be of mesopore, with a shaft volume of about 1,200 cm3/g and a shaft diameter of 100-200 angstrom. Has high porosity, and is inert as a ceramic material, it is very safe to be applied as a filter material, in the process of water consumption water treatment. A good form of porosity (mesoporous), amorphous SiO2 is able to absorb water-soluble dyes, methylene-blue. [ABSTRACT FROM AUTHOR]

Natar hot spring is one of the unique hot springs in Lampung. These springs are far from volcanoes but have geothermal manifestations. The purpose of this study is to explain the distribution and flow of Natar hot water under the manifestation of hot springs. The method used in this research is the magnetic method using a combination of the magnetometer and gradiometer. The number of measurement points is around 102 points, with a distance between points about 25 m. Data processing is with use 3D magnetic model. The results obtained are the hot water flows from the high anomaly area to the low anomaly area. High anomaly caused by rock no content hot water because hot water moves to a low anomaly area. [ABSTRACT FROM AUTHOR]

In this paper, we report the utilization of Morus alba L. leaves extraction in the preparation of SiO2/ZnFe2O4 nanocomposites. Preparation of the extinction SiO2/ZnFe2O4 nanocomposites based on Morus alba L. leaves was successfully carried out using coprecipitation and sol-gel methods. The SiO2/ZnFe2O4 nanocomposites were characterized using XRD, FTIR, and SEM-EDX. Based on the characterization carried out, structurally, the sample had two phases under its precursor, namely the crystalline phase for ZnFe2O4 and the amorphous phase for SiO2. The SiO2/ZnFe2O4 nanocomposites had a particle size of approximately 6.4 nm. Referring to FTIR spectra analysis, the precursors of nanocomposite constituents were detected based on their characteristic stretching band. The M-O stretching band representing the bond between Zn-O and Fe-O was discovered in the 471 cm−1 regions. Furthermore, stretching bands that represent the presence of SiO2 were in the area of 801 and 1083 cm-1, which represent Si-O-Si bonds, and in the region of 954 cm−1, which was a Si-OH stretching band. Finally, there were two characteristic stretching bands possessed by Morus alba L. namely, terpenoids (= N-H) and alkaloids (-N-H) in the areas of 1635 and 1396 cm−1, respectively. Based on a morphological characterization review, information was obtained that formed a particle cluster, which is a combination of primary and secondary particles with an average particle size of 38.1 nm. The elemental content characterization via EDX confirmed that all precursor elements were detected originating from matrix and filler. [ABSTRACT FROM AUTHOR]

Barium M-hexaferrite were synthesized with Co-Ni doping ions (BaFe12-2xCoNixO19) using the co-precipitation method, based on the natural iron sand of the Loang Balok beach, Sekarbela District, Mataram, Indonesia. The synthesis was carried out with variations in the concentration of doping ions (x = 0.0, 0.6, and 1.0). The characterization of the sample was completed using XRD, SEM-EDX, TEM. The XRD results showed that the sample had a hexagonal structure because it had a c / value of 2.3 to 2.6. In contrast, SEM-EDX showed that the sample size of BaFe12CoNiO19 had reached the range of nanoparticles from 41 nm to 151 nm which was evenly distributed, with a composition of Ba = 12.22%; Fe = 49.1%; Co = 8.78%; Ni = 4.76%; and O = 21.37%, and slight impurities Cl = 3.77%. [ABSTRACT FROM AUTHOR]

This study aimed to synthesize zeolite Na/H-X using silica extracted from the sand as a raw material. Silica extraction was carried out by the leaching method as a function of immersion time, followed by the sol-gel method. Extracted silica was characterized using XRF, XRD, and SEM. Synthesis of zeolite Na/H-X was conducted using the hydrothermal method by reacting NaOH, Al(OH)3, SiO2 with a mole composition ratio of 58: 58: 134. Synthesized zeolites were characterized using XRD, FTIR, XRF, SEM, and BET. The results showed that the optimal immersion time is 12 hours, where the highest silica yield obtained was 95.1 wt% and after treated with the sol-gel method was obtained 98 wt% yield of silica. The synthesized zeolite Na/H-X has the SiO2/Al2O3 molar ratios of 2.94 and 3.14. The existence of the peak of the FTIR spectrum at wavenumbers of 484, 538, 818, and 999 cm−1 indicated the presence of a specific zeolite functional group, which shows the zeolite X framework is formed. The SEM data presented the morphology of zeolite Na/H-X that crystal pieces were formed. The synthesized Na/H-X zeolites had a surface area of 14.229 and 25.147 m2/g respectively [ABSTRACT FROM AUTHOR]

This paper reports investigation results of microstructure transformation and shape memory property in Cu- 22Zn-7Al (wt%) shape memory alloy in the heat treatment process with the variable of various quench mediums. The alloy was made by the melting process of Cu ingot, yellow brass, and Al ingot. Molten metal was poured and solidified in a permanent mold. Then, solid Cu-22Zn- 7Al alloy was heat treated by homogenizing and stress relief annealing. Martensite of the alloy was formed by heating Cu-22Zn- 7Al in Beta phase temperature then continued by cooling in air, oil, water, and brine. Each cooling medium has a different effect on cooling rate. Chemical composition, microstructure, non- equilibrium transformation temperature, hardness, and shape memory properties were investigated in detail. The result shows that the martensite phase increases by enhancement of cooling rate. Alloy quenched by brine not only performs the best quality of martensite but also exhibits the highest shape memory recovery. [ABSTRACT FROM AUTHOR]

The study of pollution levels on vehicles is an important thing that needs to be studied more deeply by researchers to provide solutions to the pollution that occur due to pollution from vehicle emissions. Rock magnetization studies can be used to study various problems, such as pollution tests in the agricultural environment, rivers, and lakes. This research was conducted to develop new methods to determine the level of exhaust emissions of buses and others. Sampling was carried out by scrapping the exhaust tube of the bus on two different types of buses, i.e., 35 samples on public buses and 14 samples on tourism buses. Samples were tested to determine the elements with XRF and magnetic susceptibility tests using Bartington MS2B. The measurement results shows that the elemental content found in bottom ash samples, among others, Fe 18.6 - 72.01%, Mo 10-47%, S 7-24.5%, Ca 0.53-24.7%, P 0, 9-2.9%, Zn 0.38-2.99%, Ni 0.07-0.28%, Cu 0.17-0.4%, Mn 0.09-0.5%, Cr 0.1 -0.5%, Ti 0.16 -1,1%, Re 0.2-0.3%, 0.06-0.6%. The value of low-frequency magnetic susceptibility (χlf) the public bus samples have a range (4.00 - 343.77) × 10-8 m3/kg with an average of 46.31 × 10-8 m3/kg with an average of χfd of 3.45%. The tourism bus emission samples have a range between (5.19 - 146.37) × 10-8 m3/kg with an average of 51.880 × 10-8 m3/kg with an average χfd of 3.68%. The types of magnetic minerals found on public and tourism buses imply ferrimagnetic minerals with superparamagnetic (SP) and single stable domain (SSD). [ABSTRACT FROM AUTHOR]

Zinc ferrite (ZnFe2O4) nanoparticles is one of the semiconductor materials that can be used as a catalyst in photodegradation of malachite green. In this research, the synthesis of ZnFe2O4 nanoparticles was conducted by using the coprecipitation method with microwave assistance. Its effectivity in photodegradation of malachite green was studied. Based on the results of XRD characterization, ZnFe2O4 nanoparticles was successfully synthesized with NaOH concentration of 1, 1.5, and 2 M. The XRD diffraction peaks produced were following JCPDS Card No. 22–1012. The analysis of the BET method showed that the surface area of ZnFe2O4 nanoparticles with NaOH concentrations of 1; 1.5; and 2 M were 1,030.268; 2,225.193; and 1,974.447 m2/g respectively. In addition, the photodegradation result of malachite green showed that ZnFe2O4 nanoparticles with an NaOH concentration of 2 M was able to degrade 88.5% of malachite green in 90 minutes. [ABSTRACT FROM AUTHOR]

The effort of exploring a new stable oxide electrode for a supercapacitor has been extensively performed. For the conventional capacitor, the capacitive storage could strongly depend on high dielectric materials. Besides the high capacity, the release rate is one of the crucial issues for supercapacitors. For the latest case, we should control the optimum electrical conductivity of electrode materials, because it has an important factor to influence the high-performance supercapacitor. For those purposes, a composite combination of high ferroelectric materials of ATiO3 perovskite by introducing FC (Functionalized Carbon) with FC stands for enhancing the conductivity. The new supercapacitor materials made of FC (graphene, graphite, acetylene carbon black) and ATiO3 (A = Ba, Ca, Sr) could be a good candidate for high energy density supercapacitor. A series of ATiO3 has been synthesized using conventional solid-state reaction with intermediate calcination. The composite of FC-ATiO3 (A = Ba, Ca, Sr) with ethanol adhesive has been fabricated using conventional die pressed. The capacitance under the influence of the magnetic field was characterized using DC capacitance meter with various magnetic fields generated by a double coil magnetic generator. [ABSTRACT FROM AUTHOR]

The traditional gold mining carried out by the Labuan Kuris village community traditionally, with processing facilities located in the vicinity of the River Basion, Sumbawa Indonesia, allows the river flow to be contaminated with heavy metal processing gold waste. One effort to understand the environmental conditions was through a study of the magnetic properties of river sediments to study how pollution conditions can be responded to by the magnetic properties of the sediment. River sediment collection from upstream to downstream was carried out at 10 points. This study aims to compare the magnetic properties of river sediments before and after exposure to gold processing waste through magnetic susceptibility analysis of low frequency (χlf) and high frequency (χhf) measured using Bartington MS2B Susceptibility meter. The results showed that the average value of low-frequency magnetic susceptibility (χlf) river sediment samples before exposure to waste was 1763.50 × (10-8m3kg-1), whereas for low-frequency magnetic susceptibility values (χlf) river sediment samples after exposure to waste of 1907.33 × (10-8m3kg-1). Analysis of χlf shows that an increase in the magnetic susceptibility of river sediments from upstream to downstream after exposure to community mining waste. Through the measurement of frequency-dependent susceptibility (χfd), river sediment samples contain Multydomain (MD) and Pseudo Single Domain (PSD / SSD) grains and indicate that magnetic minerals in the environment are derived from lithogenic and anthropogenic minerals. [ABSTRACT FROM AUTHOR]

The piezometer is used to measure pore water pressure in the dam's core and placed in the upstream and downstream where if the upstream is higher than the downstream, the dam is in good condition. The piezometer measures pore water pressure based on the water levels above itself. This water level is known as a water table. This study determines the feasibility of georadar in finding pore water pressure. As a case study, this study was conducted at the Sutami dam, which has well-functioning piezometers. Measurements are made by the B-scan method at the location above the piezometer in the middle of the dam using the 90 MHz georadar. The radargram from the georadar is then analyzed in two steps, (1) determining the permittivity based on piezometer at upstream, and (2) calculating the water table at downstream based on the permittivity in the first step and comparing the result with the actual value from piezometer. The result shows that georadar can measure pore-water pressure with high accuracy. [ABSTRACT FROM AUTHOR]

This study aims to investigate the effect of Fe3O4/ZnO bilayers on photoelectrochemical properties. The Fe3O4 was fabricated by a spin coating method on the ITO coated glass substrate. While the ZnO layer was coated on Fe3O4 films using a doctor blade method. The Fe3O4/ZnO bilayer was characterized by X-ray diffraction and scanning electron microscopy (SEM) for Structural properties and surface morphology, respectively. Photoelectrochemical properties were investigated using cyclic voltammetry (CV) measurements by the potentiostat. The results of Fe3O4/ZnO bilayer is compared by Fe3O4 dan ZnO films. The XRD result showed that the crystal structure of ZnO and Fe3O4 are hexagonal and cubic spinel, respectively. The SEM results showed that the ZnO layer is more homogeneously distributed and thicker rather than the Fe3O4 layer. The photoelectrochemical properties of current density and the efficiency (η) of Fe3O4/ZnO bilayers are higher compare to Fe3O4 dan ZnO films. It means that the Fe3O4 layer can improve the photoelectrochemical properties of the ZnO film. [ABSTRACT FROM AUTHOR]

We have implemented a sparse direct solver in our transverse electric mode magnetotelluric inversion program. The two-dimensional inversion program was built on using edge finite element modeling. We also use the singular value decomposition (SVD) method in the inversion program. We test the inversion program using three different synthetic models. [ABSTRACT FROM AUTHOR]

Since 2006, Sidoarjo Mud Volcano Levee has been gradually elevated by The Sidoarjo Mud Flow Mitigation Center (PPLS). It was constructed to prevent hot mud volcano, which was unpredictably erupted and debatable among researchers, whereas it is flowing into surrounding areas. Analysis of embankment stability was conducted by Agustawijaya et al. (2012) and Widjaja et al. (2017) at point 10 D and point 21, respectively. However, the eruption on it is insufficiently stopped, although the quantity has decreased significantly. In this case, PPLS, as an authority of LUSI, performed some increased levee as an additional embankment. Nevertheless, the high embankment causes instability. They, moreover, built on the soft soil foundation that has made a significant awareness to analyze the embankment stability, particularly on the point of 10 D. A limit equilibrium method was used for evaluation of embankment stability, and the result shows that factor of safety (FoS) of the embankment is 1.7. [ABSTRACT FROM AUTHOR]

Natural surfactant-based iron oxides from Zingiber officinale extract have been successfully synthesized through the coprecipitation method. Black iron oxide-Zingiber officinale has been characterized by using an X-ray Diffractometer. The diffraction data from black iron oxide and black iron oxide-Zingiber officinale show a comparable pattern with the highest peak was at 35.7° angle and field of hkl (311). According to a calculation using the Debye-Scherrer equation, the particle size obtained from black iron oxide and black iron oxide-Zingiber officinale was 2.7 nm and 2.5 nm, respectively. The addition of Zingiber officinale extracts as the natural surfactant declined the particle size of iron oxide nanoparticles. Thus, it indicates that the abundant amount of hydroxyl within the Zingiber officinale extract effectively protects black iron oxide's surface from aggregation. Besides, the extract of gingerol full Zingiber officinale that coats the black iron oxide nanoparticle also contributed to obstructing the particle agglomeration. [ABSTRACT FROM AUTHOR]

There has not been any certain recognition for the configuration of Kendeng Basin up to recent times. The thick quartered volcanic deposits at the top layer were one of the problems in imaging the configuration of this basin. Geological data interpret that the basement of Kendeng Basin has transitional properties between accretion and continental types. The pattern of a structure due to the collision between the microcontinent of Australia and Sundaland in this Basin is still questionable. The understanding of the structure pattern is essential due to it will control the formation of the Kendeng Basin. To adds the difficulty, the basement in this basin was not exposed to the surface. Geomagnetic methods were applied to analyze the configuration of the Kendeng Basin. The measurement of Geomagnetic has carried out in the Kendeng Basin in the West and Central Kendeng with the north-south relative line. The distance between measurement points is approximately 5 Km. The pattern of Kendeng Basin can be interpreted with data processing by apply regional-residual magnetic anomalies to obtain deeper anomalies. The structural analysis was carried out on regional Anomaly data by applying several derivative formulas to produce a pattern map of the Kendeng Basin. The results of this study indicate that the basement of the Kendeng basin is a block-faulting with the East-West relative direction. West-East trending structure is the main structure. We interpret the structure to have a NE-SW oriented Meratus pattern, which formed due to early-Eocene Collision. [ABSTRACT FROM AUTHOR]

Edge finite element (finite vector element), which is solved using a sparse direct solver (PARDISO) has been used in this paper to model 2-D magnetotelluric field data (Papandayan field data). The site sounding of the field data which is used on this modeling is eight site soundings. Before using this program to model Papandayan field data, our program has been verified using COMMEMI test model. Then it showed that our program worked perfectly well. In this work, we showed how 2-D magnetotelluric modeling scheme, which is developed, can model field data. First, the generating mesh to the field data and choosing the appropriate model are reviewed. Pseudo-cross-section of the field data is important prior information needed to define the appropriate model. Second, the accuracy of the modeling result (apparent resistivity and phase) is compared to field data. In the end, it has shown that the modeling result has a good agreement with the field data in which a conductive anomaly (1.5-5 Ω·m) is showed by our program in around 200-2200 m. [ABSTRACT FROM AUTHOR]

SrTiO3 is known as high thermoelectric and ferroelectric materials. Introducing different orbitals may produce an anomalous optoelectrical effect. SrTiO3 perovskite provides d0 configuration with an energy gap of 3.2 eV and possesses ferroelectric properties. Ni with a various valence of +2, +3, +4 could be used to replace at Ti site in SrTiO3 compound will modify the normal octahedral configuration, in turn, it changed a micro elastic, crystal field, or coulomb interactions. Macroscopically, we will observe the physical properties of, e.g., magnetoelectric conductivity. SrTi1-xNixO3 was prepared by a solid-state reaction. The crystal structure of SrTi1-xNixO3 was analyzed by XRD. Electrical properties were carried out by inducing a magnetic field and light illumination during dielectric and electrical conductivity measurements, respectively. [ABSTRACT FROM AUTHOR]

Many studies have investigated a carbon phase in corncobs. This paper reports on the characteristics of structures of a carbon phase in corncob powder without heating treatment and corncob powder with a heating temperature of 400 °C for 5 hours. The X-RD data analysis showed that the phase formed in the corncob powder sample was an amorphous structure indicating the formation of the Carbon Graphite 3R phase, which had a crystal system and a rhombohedral R-3m space group. Through the X-ray diffraction pattern, corncob powder heated at 400 °C for 5 hours also indicates the formation of the Carbon Graphite 3R phase, which has a crystal system and a rhombohedral R-3m space group. In addition, impurities are also found in materials that show the formation of the O2 phase, which has a crystal system and a Pm-3n cubic space group. EDX test results also documented the element of carbon with the highest carbon composition of 71.11%. The carbon phase formed after the carbonization process has an amorphous carbon structure. Through SEM observation, the morphology of corncob powder was observed in the form of sheet-like particle aggregation with an average size of 20 µm. Meanwhile, the corncob charcoal powder, which was heated at 400 °C for 5 hours, showed a smaller aggregation with an average grain size of 0.25 µm. The results of FTIR data analysis portrayed that there was a strain of C=C bond in corncob powder in the wavenumber position of 2517.1 cm-1, which represented the formation of benzene structure, which is a characteristic of carbon structure in graphite and graphene. However, this bonding strain did not appear in samples that were given a heating treatment up to 400 °C for 5 hours. [ABSTRACT FROM AUTHOR]

Anthropogenic activity in coastal areas causes environmental pollution by heavy metals. One of the heavy metals that polluted seawater is Fe, which is possibly contributed by fishing boats and tourism activities. Monitoring and assessments of Fe are important to protect the environment. To solve the problem of the polluted Fe in the environment, we need to develop the method quickly. This study used a microwave optimized Bureau Community of Reference (BCR) method with variations in solvent concentration and pH to attack Fe at fraction 2 (Fe-MnO2) in sediment. The sample was collected from Pasir Putih Beach waters sediment at 5 m below sea level. The results showed that increasing the concentration of NH2OH.HCl at fraction 2 revealed the leaching process of Fe more optimally. In the analysis of the level of Fe pollution to the environment around the Pasir Putih Beach did not indicate the potential of Fe from anthropogenic activity. Most of the Fe sources in the Pasir Putih Beach area were Fe sourced from nature. [ABSTRACT FROM AUTHOR]

Nowadays, graphene has attracted scientific community's attention due to its outstanding properties. In this paper, we reported the absorption capacity of Tuban silica sand to dyes in drinking water that could be improved by graphene coating onto the silica surface. Coatings of sand with graphene from sugar through the hydrothermal-vapor heating method were conducted at a temperature of 700 °C. The pattern of X-ray diffraction (XRD) of the as-prepared silica sand shows the existence of a quartz crystalline phase, with a weight percentage of 98%. In contract with that XRD profile, the graphene-coated sand (GCS) XRD pattern tends to be amorphous due to the presence of amorphous carbon. Furthermore, the UV-Vis test reveals a significant reduction in peak absorption intensity of methylene blue by silica sand and the GCS material. [ABSTRACT FROM AUTHOR]

Mud Volcano is a phenomenon often being discussed by people. The emergence of mud volcano in Sidoarjo, East Java, or better recognized as "LUSI" has attracted the attention of researchers and the general community. The effects of infrastructure destruction and environmental damage around the emergence of the Mud Volcano are issues that need special attention. The potential for mud volcano has been recorded in lots of locations in Java, both active and interpreted based on rock deposits. One of the areas indicated to be an ancient mud volcano is the Cengklik Lake area of, Boyolali Regency, Central Java, that is observed in this research. This research was conducted using the geomagnetic method. The investigation was performed around CengklikLake to the east following rock outcrops, which are identified as mud volcano deposits. The interpretation is made based on the results of data processing that have been corrected by daily variation and IGRF. Several filters have been applied to obtain the desired information. The results have shown a low magnetic anomaly value spread from Cengklik Lake, AdiSumarmo Airport on the west side, and continuously spread eastward until around the outcrop, which was identified as ancient volcanic deposits. This pattern of low magnetic anomaly values is interpreted as a result of mud volcano deposits in the area. [ABSTRACT FROM AUTHOR]

In this paper, we report the preparation of nanosized magnetite/titania@emeraldine by polymerization route. The quantitative analysis of X-ray diffraction data showed the presence of two crystalline phases in the nanocomposites. Those were magnetite with cubic inverse spinel structure and titania with anatase structure. Meanwhile, the existence of emeraldine was confirmed by its functional groups indicated by the vibration of C-H in-plane and out-plane. The C-N of the benzenoid ring, C=C of the quinoid ring, and stretching N-H functional groups at the respective wavenumbers of 808 and 1149, 1305-1326, 1501, and 3705-3760 cm−1. The functional groups of magnetite and titania were also detected by the vibration of Fe-O at the tetrahedral and octahedral sites at the wavenumbers of 523 and 452 cm−1 for magnetite and Ti-O- Ti in the wavenumber range of 645-685 cm−1 for titania. Based on the scanning electron microscopy image, the morphology of the magnetite/titania@emeraldine nanocomposites tended to agglomerate. The magnetic properties showed that the nanocomposites exhibited superparamagnetic behavior with the saturation magnetization of 1.81 emu/g. Furthermore, the bandgap energy of the nanocomposites was 2.180 eV for magnetite and 3.344 eV for titania. [ABSTRACT FROM AUTHOR]

Arjuno-Welirang Mountain is located in East Java province, which is a type of stratovolcano with an altitude of 3,339 m for Arjuno and 3,156 m for Welirang. The Arjuno-Welirang geothermal system is a volcanic geothermal system. Magnetotelluric is the most commonly used geothermal exploration method because of its deep penetration and sensitivity to conductive zones. The Magnetotelluric method measures 103 MT points in the field of geothermal systems in the South of Mount Arjuno-Welirang. In this study, the 3D inversion model of Magnetotelluric data was used to reduce the ambiguity of 2D Magnetotelluric inversion data. 3D Model Inversion uses WinGlink and 3DModEM. The steps of Magnetotelluric processing consist of time-domain conversion to the frequency domain, cross power selection, data smoothing, static effect correction, 2D and static strips, interpolation, masking, 3D inversion, and interpretation of inversion models. The 3D model inversion consists of 3D mesh grid parameters used by the NonLinear Conjugate Gradient Algorithm. 2D Inversion Modelling was done by the NLCG method, which produces a 2D model with an RMS error of 1.7%. 3D Inversion modeling was done by the NLCG method producing a 2D model with a value of RMS error of 2.83%. The geothermal system of the Arjuno-Welirang geothermal region consists of a layer of veil rock with a type of resistivity value of 5-11 Ωm, a middle resistivity zone with a value range of 11-76 m acting as a reservoir, and a high resistivity zone with a range of 76-500 Ωm or commonly called heat source. The results of the 3D inversion model indicated a range of low resistance types (hood rock layers) that have a thickness of 1200 - 1700 m, the value of this type of resistance is below the surface with a thickness of ±500-600 m. Thus, the Mt. Arjuno-Welirang is a geothermal prospect area. [ABSTRACT FROM AUTHOR]

Electrification is one of the driving factors for improving the life quality of a country. Currently, Indonesia electrification is borne solely by Perusahaan Listrik Negara (PLN), which aren't sustainable and eco-friendly due to its main energy source is fossil fuel. Gorontalo, which is endowed with abundant renewable energy resources has installed many renewable power plant energies, but some of them have stopped operating due to an inability to maintain the operation. In South Dulamayo Village, which its energy supply has already dominated by PLN, there is still a renewable energy power plant. The microhydro power plant project (MHPP) in South Dulamayo has operated for more than seven years old. It currently struggles to maintain its sustainability. This study focused on capturing how the microhydro power plant in South Dulamayo maintains its sustainability. It is possible to keep The MHPP South Dulamayo working together (hybrid) with PLN for several customers, mainly manage by the intervention of UNG researchers. [ABSTRACT FROM AUTHOR]

Magnetic susceptibility and geochemical data have been widely used in environmental studies. In general, the data are analyzed only based on the correlation between variables. In this paper, the multivariate statistical analysis method is used intensively to identify environmental conditions based on magnetic susceptibility and geochemistry. The objects of this research are the two inlet rivers of Sentani lake, Papua, Indonesia, namely the Hubay and the Kamp Wolker River. In this study matrix correlation, principal component analysis (PCA) and the factor analysis technique were employed in the analysis task. Using the methods, we found the characteristic of geochemical elements and their correlations with magnetic susceptibilities, and dominant geochemical elements in the inlet rivers, which distinguishes the two rivers significantly. [ABSTRACT FROM AUTHOR]