2D Forward Modeling Geothermal System Gravity Data in South Solok Region, West Sumatra

Indonesia has the greatest potential for geothermal energy in the world. Geothermal has an important role as an alternative fuel because it is a renewable energy source, but its use has not been maximized. One of the areas that have the greatest potential for geothermal energy in South Solok, West Sumatra. Therefore, this study was conducted to determine the geothermal system in the South Solok area, West Sumatra by using the gravity method. The gravity data processing stage requires some software to get the CBA value(Complete Bouguer Anomaly), map contours of the CBA. Anomaly separation with the butterworth filter method, determination of residual anomaly slice points, and 2D modeling of geothermal systems. Based on modeling, the qualitative interpretation interprets the Complete Bouguer Anomaly map which is suspected as a geothermal prospect area is a low anomaly ranging from 7.9 mgal - 9.4 mgal which is marked in dark blue. Meanwhile, quantitative interpretation produces modeling of the AB and CD slicing with a total of four layers. This layer consists of clay rock as a cap rock, sandstone as a reservoir, granite as a heated rock as a heat source, and the last layer in the form of magma as a heat source. The anomaly modeling of these two sections is dominated by granite rock with a density value of 2500 kg/m3 for the AB section and 2550 kg/m3 for the CD section.

Analysis of Superhydrophobic-Superoleophilic Properties on Modification of Polyurethane Sponge for Selective Oil-Water Separation

In this research, a modification of polyurethane (PU) sponge material has been made to obtain superhydrophobic-superoleophilic properties. The PU sponge was coated with several nanomaterials such as ZnO, Fe3O4+TEOS, and stearic acid by dip-coating and drop-coating methods. The tests include selective separation of oil and water with a magnetic response. Several types of oil and organic solvents were tested for absorption capacity. The results showed that the PU@ZnO@Fe3O4@SA sponge has a good absorption capacity, from 4.37 mL to 7.37 mL. The fabricated PU sponge could selectively separate oil from water with a separation efficiency above 99%. The fabricated PU sponge also could be magnetically driven by external magnetic fields. From the characterization using 3D OM, the water contact angle was 153.38°, which indicates that the PU@ZnO@Fe3O4@SA sponge is superhydrophobic. And from surface morphology obtained an average pore size diameter of 167.475 μm.

Simultaneous Seismic Inversion for Reservoir Characterization at Poseidon Field, Browse Basin, Australia

Seismic inversion method has been widely used to obtain reservoir property in an oil and gas field. In this research, one of inversion methods known as simultaneous inversion is used to analyze reservoir characterization at Poseidon Field, Browse Basin. Simultaneous inversion is applied to partial angle stack data and result in volume of Acoustic Impedance (AI), Shear Impedance (SI) and Lame parameter (LMR). The objective of this study is to determine distribution of sandstone lithology with gas saturated in Plover reservoir formation. Sensitivity analysis is done by cross-plotting elastic and Lame parameter from five well log data and analyzing lithology type and fluid saturation. Based on those cross-plots, lithological type can be identified from AI, λρ, µρ and λ/µ parameters. Meanwhile, the presence of gas can be discriminated using SI, λρ, and λ/µ parameters. Gas-saturated sandstone presence is characterized by Lambda-Rho value less than 50 GPa g cc-1 and Lambda over Mu value less than 0.8 GPa g cc-1. Maps of each parameter are generated at reservoir interval. Based on those maps, it can be concluded that gas sand spread out in the eastern and western areas of research area.

Application of the Acoustic Impedance (AI) Seismic Inversion and Multi-Attribute Method for Reservoir Characterization in Bonaparte Basin

Research on the application of the acoustic impedance (AI) seismic inversion and multi-attribute method was conducted with the aim to characterize the reservoir in the Bonaparte Basin. The modeling which used in the acoustic impedance inversion seismic method is model-based. Meanwhile, the multi-attribute seismic method used log porosity that appliying the linear regression method and using the stepwise regression technique. Based on the result of the sensitivity analysis and analysis using the seismic inversion acoustic impedance method, the sandstone reservoir zone that has the prospect of hydrocarbons containing gas is located in the Northeast-Southwest part of the study area which in WCB-1, WCB-3 and WCB-4 well with the acoustic impedance values are in the range of 4,800 - 13,000 (m / s) * (g / cc), and the porosity values generated from the analysis using the multi-attribute seismic method are in the range of 5 - 16% in WCB-1 and WCB-4, 2 - 10% on WCB-3.

ANALYSIS OF MOISTURE CONTENT, CALORIFIC VALUE AND BURNING RATE OF CORNCOB AND KAPOK RANDU (Ceiba pentranda) SKIN BRIQUETTE

Bio charcoal Briquette is a product made from biomass with a carbonization process and compressed with a certain shape. This study aims to examine the calorific value and burning rate of corncob and kapok randu (Ceiba Pentranda) randu (Ceiba pentranda) skin briquettes with variations in the composition of ingredients. The briquette were produced in 5 stages: First, the main material for cobs and kapok randu (Ceiba Pentranda) randu skin is dried in the sun for 3 days so that the weight of the ingredients is reduced by 20%. Second, the carbonization of the main material with a temperature of 400˚C for 60 minutes with a furnace and then materials that has been crushed is sieved with a sieve 50 mesh. Third, compressed briquettes with corncob composition and kapok randu (Ceiba Pentranda) skin in the following ratios of A (100%: 0%), B (75%: 25%), C (50%: 50%), D (25%: 75 %), E (0%: 100%) with 10% w/w tapioca starch as binder. Fourth, the dry the briquette under the sun for 3 days (20 hours) and roasted with a temperature of 100˚C for 60 minutes. Fifth, after dried, the samples were then characterized their moisture content, calorific value, and burning rate. The results show that the highest moisture content value in sample E is 3.3303% and the lowest moisture content in sample B (2.4587%). The highest calorific values are sample E which is 6195.05 Cal / grams. While the lowest calorific value was found in sample D (25% corn cobs and 75% kapok randu (Ceiba Pentranda) skin), which was 3803.96 Cal / grams. The lowest burning rate was found in sample E (100% kapok randu (Ceiba Pentranda) skin) with a value was 0.0448 grams / minute. While the highest burning rate was found in sample D (25% corn cobs and 75% kapok randu (Ceiba Pentranda) skin) with the value was 0.0622 grams/minute.

Ohmic and Diamagnetic Currents Contribution on the Electromagnetic Penetration Depth of a Conducting Surface

Due to its conducting electron, metal is a good reflector for electromagnetic wave. An electromagnetic wave penetrating a metallic surface has a finite penetrating depth. There are two limit that are well studied in the physics textbooks. They are high frequency electromagnetic wave penetrating a metal with small conductivity and a static (low frequency) field penetrating a superconductor (metal with infinitely large conductivity). In this article we study the intermediate regime between these two limits. By setting the electric current density as the total sum of both Ohmic and Diamagnetic currents, we derive the penetration depth in the intermediate regime., we show the transition between these two limits.

Investigation of Thermal Properties of Half-Heusler Alloy FeVZ (Z= As, P, Sb) within Density Functioal Theory

The figure of merit (ZT) holds an important role in thermoelectric material that indicates the efficiency of thermoelectric (TE) devices. The higher ZT value, the higher efficiency would be obtained of TE devices. One of the sub-class materials that has high potential application for thermoelectric material is half-Heusler (HH) alloy. In order to investigate the ZT value of HH conduct simulation using to investigate the ZT value of HH alloy FeVZ (Z= As, P, Sb) by using density-functional theory (DFT). Our research results show that FeVAs has higher ZT values than FeVP and FeVSb in the range temperature of 150-900 K. All of those compounds still have good ZT value around ~0.7 even in the temperature regime of 900 K, and shows a good trend for p-type thermoelectric materials.

Water Level Detection System based on Arduino and LabVIEW for Flood Monitors using Virtual Instrumentation

This virtual instrumentation system based on Arduino and LabVIEW aims to detect the water level using a water level sensor. The water level sensor used to measure the water level is the Funduino type. This sensor and the buzzer module are connected to the Arduino Uno to transmit data to LabVIEW. When the water has reached a certain height, this sensor will detect the water level. When the water has reached the set point, this sensor will sound a buzzer as a sign that the water is full. Based on the experimental results, it is found that the tension value affects the volume of the experiment site. Where the greater the volume used will produce a large voltage, and vice versa. Furthermore, the graph results obtained that are still away from the linearity of a regression function with a value of y = 0.0079x + 1.8561 and R² = 0.4298.

Solusi Metrik Kerr-Newman Untuk Dimensi Ruang-waktu 3+1 Dengan Invariansi Rotasi Anisotropik

Metrik Kerr-Newman merupakan solusi umum dari persamaan medan Einstein dengan mengasumsikan metrik ruang waktu melengkung akibat keberadaan objek masif bermassa dan bermuatan, serta memiliki simetri anisotropik akibat rotasi. Metrik Kerr-Newman untuk dimensi ruang-waktu 3+1 diformulasikan pertama kali oleh Ezra Newman. Algoritma umum untuk memformulasikan metrik ini yaitu dengan menggunakan persamaan medan Einstein secara eksplisit, yang meliputi kalkulasi koneksi affine, tensor Ricci hingga tensor energi-momentum. Dimana, formulasi ini tidaklah sederhana. Untuk menyederhanakan formulasi metrik Kerr-Newman untuk dimensi ruang-waktu 3+1, pada artikel ini dilakukan formulasi dengan algoritma alternatif tanpa menggunakan persamaan medan Einstein secara eksplisit. Kemudian, karena algoritma alternatif ini tidak menggunakan persamaan medan Einstein secara eksplisit dan supaya memperoleh solusi metrik Kerr-Newman secara utuh, maka digunakan prinsip limitasi properti metrik Kerr-Newman untuk membawa persamaan medan Einstein secara implisit. Berdasarkan prinsip limitasi properti metrik Kerr-Newman, dilakukan rekayasa matematis atas fungsi temporal serta fungsi radial dari metrik Reissner-Nordstrom dan metrik ruang-waktu datar dari sistem simetri anisotropik akibat rotasi, yang diturunkan dari transformasi koordinat elipsoid oblate. Dan meski formalisme dengan algoritma alternatif ini relatif sederhana, solusi metrik Kerr-Newman untuk dimensi ruang-waktu 3+1 pada artikel ini serupa dengan hasil formalisme dengan algoritma umum.

Identifikasi Objek Bawah Permukaan Untuk Fondasi Jalan Tol di Jakarta Menggunakan Metode Ground Penetrating Radar (GPR) Pada Segmen Area Y

Penelitian ini dilakukan di Jakarta dengan tujuan untuk mendeteksi keberadaan utilitas di bawah permukaan tanah sebelum dilakukan pembangunan fondasi jalan tol. Saat ini Jakarta sedang melakukan pembangunan infrastruktur jalan tol. Untuk itu perlu diketahui apakah ada utilitas di bawah permukaan tanah yang dapat mengganggu pembangunan fondasi jalan tol. Penelitian ini dilakukan dengan menggunakan metode Ground Penetrating Radar (GPR). Terdapat 32 lintasan yang datanya telah diolah menggunakan software reflexw 2008. Dari hasil pengolahan dan interpretasi adanya material pasir kering dengan kecepatan gelombang 0,140 m/ns pada kedalaman ~1-2m. Jenis anomali dari radargram menggambarkan lempengan berbentuk kotak dan hiperbola yang menunjukkan utilitas berbentuk silinder. Dari lintasan 1 – 32 terdapat 115 utilitas yang bisa mengganggu pembangunan fondasi jalan tol. Lintasan 5 merupakan lintasan yang paling banyak adanya utilitas terdeteksi sebanyak 6, sedangkan lintasan 10, 23 dan 28 memiliki utilitas terdeteksi paling sedikit sebanyak 2, untuk lintasan 18 dan 19 memiliki 5 utilitas terdeteksi, kemudian lintasan 2, 3, 7, 8, 11, 12, 16, 20, 22, 25, 26, 27, 29, 30, 31 terdapat 4 utilitas terdeteksi, dan lintasan 1, 4, 6, 9, 13, 14, 15, 17, 21, 24, 32 terdapat 3 utilitas terdeteksi. Dari utilitas yang terdeteksi itu perlu dilakukan konfirmasi dengan Lembaga yang mempunyai utilitas tersebut.