Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics
Al-Fiziya is a physics journal published by the Department of Physics, Faculty of Science and Technology, UIN Syarif Hidayatullah Jakarta. The journal aims to disseminate research conducted by scholars from Indonesia and overseas. Articles should be written in English. The journal focuses on physics fields including Materials Science, Geophysics, Instrumentation Physics, and Theoretical Physics, and welcomes contributions from researchers worldwide.
Department of Physics, Faculty of Science and Technology, UIN Syarif Hidayatullah Jakarta
LITHOFACIES INTERPRETATION OF CORE SAMPLES IN THE TANJUNG PASIR BEACH, TELUK NAGA, TANGERANG, BANTEN
This research was conducted at Tanjung Pasir Beach, Teluk Naga Sub-district, Tangerang Regency, Banten. The objective of this research was to analyze the sedimentary structures, describe lithology, and determine facies in a depositional environment. This facies interpretation can be as a reservoir analogue for subsurface interpretation in the Northwest Java Basin. The research data used include surface sand samples and core samples from Tanjung Pasir Beach. The facies interpretation shows that core at location 1 is dominated by carbonaceous shale with parallel lamination structures, indicating sedimentary of lagoon environment. In contrast, core at location 2 is predominantly composed of medium- to coarse-grained sandstone facies, representing a shoreface environment.
Copyright (c) 2025 Sundus Ghaida Noor Azizah, Suwondo, Andi Krisyunianto, Agus Budiono https://creativecommons.org/licenses/by-sa/4.0
PREDICTIVE DECONVOLUTION BASED ON SEISMIC WAVEFORM DIAGNOSTICS FOR ENHANCED MARINE IMAGING RESOLUTION
Short-period multiples are a persistent problem in marine seismic processing, particularly in shallow-water environments where near-surface reverberations interfere with primary reflections and decrease temporal resolution. Predictive deconvolution remains a widely used method for attenuating such coherent noise. However, conventional implementations often apply fixed operator parameters, limiting their adaptability to waveform variations across time and offset. This study introduces a predictive deconvolution framework guided by seismic waveform diagnostics, in which operator parameters specifically prediction lag and filter length are selected based on trace characteristics such as waveform periodicity and spectral energy distribution. The approach is designed to improve multiple suppression while preserving the fidelity of primary reflections on a 2D marine pre-stack seismic dataset acquired in a shallow offshore setting characterized by strong short-period multiples and limited bandwidth. The results demonstrate around 25% increase in frequency bandwidth, improved reflector continuity, and reduced coherent noise in pre-stack gathers. Compared to conventional deconvolution, the waveform informed design achieves a more effective balance between attenuation and resolution. The proposed approach is applicable to modern marine datasets where high-resolution imaging is limited by near-surface interference.
Dhani Nur Indra Syamputra Dhani Nur Indra Syamputra
Copyright (c) 2025 Muhammad Fahmi, Dhani Nur Indra Syamputra Dhani Nur Indra Syamputra, Wiji Raharjo Wiji Raharjo, Tri Wulan Sari Tri Wulan Sari, Muhammad Nafian Muhammad Nafian https://creativecommons.org/licenses/by-sa/4.0
HAZARD AND RISK MAPPING OF TSUNAMI DISASTER USING HLOSS METHOD CASE STUDY: IDANO GAWO DISTRICT
Idano Gawo District, Nias Regency has geographical characteristics that are vulnerable to tsunami. Based on the history of the earthquake in the Nias Islands in 2005, there was a release of megathrust earthquake energy caused by disturbance of the big Aceh earthquake on December 26, 2004. This earthquake was followed by a 2-3 meter high tsunami that hit several coastal areas in the Nias Islands, so disaster mitigation is needed. Mapping tsunami hazards and risks is an important effort for effective mitigation planning, by knowing the area of ​​​​danger and tsunami risk based on a 16 meter height scenario. The method used in this study is the hloss and cost distance methods. Mapping the level of tsunami hazard and risk with a height of 16 meters using Arcgis Software. For processing tsunami disaster hazard and risk data using Microsoft Excel Software. Bozihona Village is an area that has a high level of danger with a total area of ​​​​3.76 km2 and a high level of tsunami risk with a total area of ​​​​3.77 km2.
Lailatul Husna Lubis Lailatul Husna Lubis
Copyright (c) 2025 Lailatul Husna Lubis, Erry Sahputra, Tia Melati https://creativecommons.org/licenses/by-sa/4.0
Harnessing Machine Learning for Caprock Capacity and Seal Integrity Assessment in CCS: A Multi-Attribute Seismic Inversion Study from the F3 Block, North Sea
Accurate characterization of subsurface petrophysical properties is a critical prerequisite for evaluating the suitability of geological formations for carbon capture and storage (CCS), particularly in identifying high-capacity reservoirs and effective sealing intervals. This study explores the use of a machine learning approach—Random Forest (RF) regression—for multi-attribute seismic inversion to predict porosity and acoustic impedance in the F3 Block, offshore Netherlands. The integration of ten seismic attributes with two well log datasets enables the construction of predictive models capable of resolving complex lithological variations within deltaic settings. The RF algorithm’s robustness against geological noise and its ability to model nonlinear relationships offer significant advantages over conventional inversion workflows, especially in heterogeneous and interbedded formations. The results demonstrate that RF-based inversion produces petrophysical volumes with improved spatial continuity and alignment with depositional patterns, offering a promising avenue for CCS site screening and reservoir-seal evaluation. The method’s ability to capture subtle textural and facies changes also enhances understanding of potential CO₂ migration pathways and trap integrity. This research underscores the potential of data-driven inversion frameworks in supporting geoscientific decision-making for CCS development, particularly in data-limited or geologically complex offshore regions.
Copyright (c) 2025 Fadhlur Rahman , Abdul Haris, Dwandari Ralanarko, Humbang Purba, Wrahaspati Rulandoko, Praditio Riyadi, Muhammad Nafian https://creativecommons.org/licenses/by-sa/4.0
DAMAGE ANALYSIS OF INSULATED PIPES USINGDIGITAL DETECTOR ARRAY AND COMPUTED RADIOGRAPHY
The provision of insulation on the pipe functions to prevent heat transfer, but the provision of this insulation causes the pipe to be susceptible to damage due to oxidation. In this study, an analysis of damage to insulated pipes will be carried out using a Digital Detector Array (DDA), Computed Radiography (CR), and XRF. Based on the test results, it is known that the image quality using DDA with a voltage of 240 kV produces the most optimal contrast resolution. The results of the thickness dimension measurement using the DDA method on insulated pipes are 3.38 mm, and on insulated pipes with artificial defects are 4 mm. Compared with the CR method, the values are 3.02 mm and 3.94 mm, respectively. The smaller the difference, the more accurate. From the calculation of the ISee software, it is also known that the DDA method can detect a greater number of defects, namely 24, compared to the CR method, which has only 14. The results of the XRF test show that the insulated pipe includes low-carbon steel with a carbon content of 0.057% and 94% ferrum. This high ferrous content contributes to increased X-ray absorption, greatly affecting the images quality.
Sitti Ahmiatri Saptari1 Ahmiatri Saptari
Copyright (c) 2025 Elfriani Dita Pratama, Arif Tjahjono, Baskan Hanurajie, Sitti Ahmiatri Saptari1 Ahmiatri Saptari, Biaunik Niski Kumila https://creativecommons.org/licenses/by-sa/4.0
Physics-Guided Multi-Attribute Petrophysical Inversion for Quantifiying Acoustic Impedance and Porosity in the F3 Reservoir
This study introduces a physics-guided multi-attribute inversion (PG-MAI) approach to estimate acoustic impedance and porosity from post-stack seismic data using Bayesian Ridge Regression. The method integrates ten seismic attributes—including amplitude, frequency, and geometric features—into a regularized linear regression framework with Bayesian formulation. Applied to the F3 Block in the Dutch North Sea, the workflow includes temporal upsampling, attribute extraction, and model calibration using two well logs. The inversion results demonstrate high spatial coherence and alignment with geological structures. Validation at both wells shows strong agreement between predicted and measured log values, with correlation coefficients exceeding 0.90 for both acoustic impedance and porosity. Zones of low impedance and high porosity correspond to interpreted deltaic sands and lobate geometries, reflecting the facies heterogeneity of the F3 depositional environment. These outcomes suggest that the inversion framework effectively captures lithological variability, making it valuable for reservoir delineation in similarly complex siliciclastic systems.
Copyright (c) 2025 Fadhlur Rahman, Abdul Haris, Dwandari Ralanarko, Humbang Purba, Wrahaspati Rulandoko, Praditio Riyadi, Muhamamd Nafian, Muhammad Fahmi https://creativecommons.org/licenses/by-sa/4.0
SYNTHESIS AND CHARACTERIZATION OF ACTIVATED CARBON FROM MALAPARI PRESS CAKE, MALAPARI SHELL, AND CASSAVA PEEL
Activated carbon is increasingly used in various applications, prompting researchers to innovate by utilizing biomass as a source for activated carbon. This study used biomass waste from malapari press cake, malapari shell, and cassava peel. The process involved carbonizing the samples at 500°C for 2 hours, chemical activation using a 65% (w/v%) KOH solution at a 1:4 ratio, stirring with a magnetic stirrer at 120°C and 300 rpm for 2 hours, followed by physical activation at 550°C for 1 hour, and BET & SEM-EDS testing. Based on the BET test results, the surface area of the samples increased overall between pre- and post-activation. The highest increase in surface area occurred in cassava peel, which increased from 7.916 m²/g to 294.303 m²/g. Meanwhile, the malapari press cake increased from 3.122 m²/g to 11.445 m²/g, and the malapari shell increased from 12.773 m²/g to 105.320 m²/g. SEM-EDS characterization revealed that cassava peel contained the highest carbon content at 67.02%, and after activation, each sample exhibited porous surfaces, uneven textures, and various pore shapes. ImageJ software analysis showed cassava peel had the smallest pore size at 123.209 nm, compared to malapari press cake at 234.721 nm and malapari shell at 217.419 nm. These results indicate that samples with larger surface areas tend to have smaller average pore sizes.
Copyright (c) 2025 Sayida Ma'wa A'yuni https://creativecommons.org/licenses/by-sa/4.0
PHYSICAL TESTS OF ORGANIC INK BASED ON GUM ARABIC, GAMBIER, AND JANGGELAN LEAVES
The basic color of ink is black, which contains carbon, making it easier for us to use natural elements around us as the raw material for making organic ink, and it is, of course, more cost-effective. One potential natural material that can be used as a color source to replace synthetic materials in ink production is gum arabic, gambier, and janggelan leaves. This study aims to determine the physical tests of organic ink made from gum arabic, gambier, and janggelan leaves based on the Indonesian National Standard (SNI) No 06-1567-1989. The physical tests conducted include density, viscosity, and color pigment tests. The results of testing the three materials used—gum arabic, gambier, and janggelan leaves—showed that gum arabic is the most optimal for making organic ink. This is evident from the test results, which showed a density of 1.076 g/cm³, a viscosity of 2.56 poise, and a deep black color pigment.
Copyright (c) 2025 Masthura Masthura, Ikhwani Pasha, Sri Wulandari, Hilwa Panjaitan, Devi Ramadhani
EFFECTIVENESS OF THE FILTRATION METHOD USING ACTIVATED CARBON FROM KEPOK BANANA PEELS AND ZEOLITE TO REDUCE KMnO4 LEVELS
The effectiveness of the filtration method using activated carbon from Kepok banana peels and natural materials such as zeolite has been studied. This research aims to reduce KMnO4 levels in well water so that it can be used for human needs. The well water samples used in the testing process with the filtration method were taken from a well located in Medan Marelan District, Tanah 600 Sub-district, North Sumatra Province. The utilization of Kepok banana peels for activated carbon to reduce KMnO4 levels involved using the chemical activator HCl 3M for 7 hours and an activation temperature of 600ºC for 45 minutes. The variations in composition used in the filtration method were sample A (75%:25%), sample B (50%:50%), and sample C (25%:75%). The most effective filtration result in reducing KMnO4 levels was sample A, with a KMnO4 reduction of 86.7%, which meets the clean water quality standards according to PERMENKES RI No 32 of 2017.
Copyright (c) 2025 Ety - Jumiati, Miftahul - Husnah, Auly - Asyari
Reservoir Characterization Using Amplitude Versus Offset (AVO) Analysis of Lakota Formation, Teapot Dome Field, Wyoming, USA
Lakota Formation is one of the prolific formations at Teapot Dome Field. The objective of this study is to analyze hydrocarbon potential of Lakota Formation using Amplitude Versus Offset (AVO) analysis. AVO analysis is performed to determine AVO class, intercept (A) and gradient (B) values of Lakota reservoir. This study uses pre-stack 3D gather data and three wells, 17-WX-21, 48-X-28 and 41-2-X-3. The Lakota formation is known to be an oil-bearing sandstone reservoir which supported by log interpretation. Analysis of AVO modelling using well data by crossplotting reflectivity (R) with sin2 θ, shows that the Lakota Formation is in Class IIP for wells 17-WX-21 and 41-2-X-3 and Class II for well 48-X-28. An estimation of AVO intercept and gradient based on the seismic data show that the Lakota Formation is class II AVO response. A-B plane shows that the pay zones of Lakota formation are fall within hydrocarbon zone, but very close to background trend (wet sands/shale). AVO attributes; A*B and scaled Poisson Ratio at well location showing difficulty in differentiate the presence of oil and brine. Therefore, it can be concluded that AVO attributes can not distinguish between water and oil zone in Lakota Formation, and therefore we can not determine distribution of oil in the Lakota reservoir.
Copyright (c) 2025 Nadia Samudera, Ida Herawati
SEISMIK VULNERABILITY INDEX ANALYSIS IN NAGARI MALALAK TIMUR AS AN EFFORT TO DETERMINE LANDSLIDE POTENTIAL AREAS THE HVSR METHOD
Nagari Malalak Timur, Malalak Subdistrict, Agam Regency has experienced landslides caused by soil movement so that the soil conditions become unstable. Landslides are also influenced by external factors such as vibrations from earthquakes and vibrations from human activities. For this reason, a study was conducted to describe the distribution of seismic vulnerability index as an effort to determine the potential landslide area. The sampling was limited to 10 measurement points using a set of seismograph sysmatrack MAE sensor type S3S. The basic principle of HVSR method is to obtain the value of Dominant Frequency (f0) and Amplification Factor (A0) by comparing the value of horizontal component and vertical component of microtremor data. From the value of Dominant Frequency (f0) and Amplification Factor (A0), the calculation of Dominant Period (T0) and Seismic Susceptibility Index (Kg) can be done. The results of research in Nagari Malalak Timur show the value of Dominant Frequency (f0) is in the range of 2.676 - 7.22 Hz. The Amplification Factor (A0) value is in the range of 1.4 - 6.563. The Dominant Period (T0) value is in the range of 0.138 - 0.373 s. The Seismic Susceptibility Index (Kg) value is in the range of 0.365 - 14.62 cm/s2. Based on the distribution of Seismic Susceptibility Index (Kg) values in the 10 research points, the highest landslide potential is in point D with a Seismic Susceptibility Index (Kg) value of 14.62 cm/s2. This causes landslides to occur at any time. Keywords: Amplification Factor, Dominant Frequency, HVSR, Seismic Susceptibility Index
Copyright (c) 2025 Yese Angga Marito Silitonga
Synthesis and Characterization of Activated Carbon From Biomass Waste as A Microwave Absorber Material
Excessive use of electronic technology can result in harmful radiation and electromagnetic interference, which pose risks to human health. To address this issue, researchers developed a material designed to absorb electromagnetic waves. The study focused on synthesizing and characterizing activated carbon derived from biomass waste, including water hyacinth, melinjo seed shells, and chicken eggshells, with the goal of reducing electromagnetic wave interference. The research process involved several key steps: washing the biomass materials, followed by carbonization, activation using a 65% KOH solution, and subsequent characterization of the material. The tests revealed that the activated carbon possessed a porous structure, which is essential for its absorption capabilities. The surface areas measured were 4.378 m²/g for water hyacinth, 2.518 m²/g for melinjo seed shells, and 2.992 m²/g for chicken eggshells. These surface areas are indicative of the material's potential effectiveness. Additionally, the microwave absorption capacities of the activated carbon were recorded as -18.342 dB for water hyacinth, -13.326 dB for melinjo seed shells, and -12.484 dB for chicken eggshells. These findings suggest that the activated carbons are highly effective as microwave absorber materials, with an absorption efficiency ranging between 94% and 98%. Excessive use of electronic technology can result in harmful radiation and electromagnetic interference, which pose risks to human health. To address this issue, researchers developed a material designed to absorb electromagnetic waves. The study focused on synthesizing and characterizing activated carbon derived from biomass waste, including water hyacinth, melinjo seed shells, and chicken eggshells, with the goal of reducing electromagnetic wave interference. The research process involved several key steps: washing the biomass materials, followed by carbonization, activation using a 65% KOH solution, and subsequent characterization of the material. The tests revealed that the activated carbon possessed a porous structure, which is essential for its absorption capabilities. The surface areas measured were 4.378 m²/g for water hyacinth, 2.518 m²/g for melinjo seed shells, and 2.992 m²/g for chicken eggshells. These surface areas are indicative of the material's potential effectiveness. Additionally, the microwave absorption capacities of the activated carbon were recorded as -18.342 dB for water hyacinth, -13.326 dB for melinjo seed shells, and -12.484 dB for chicken eggshells. These findings suggest that the activated carbons are highly effective as microwave absorber materials, with an absorption efficiency ranging between 94% and 98%.
Copyright (c) 2025 Muhammad Ishaq Nuras, Sitti Ahmiatri Saptari, Arif Tjahjono, Danang Pamungkas Priambodo, Amanda Haiqal
DESIGN OF SAFETY FACTORS FOR LANDSLIDE POTENTIAL AND ANDESITE MATERIAL SLOPES GEOMETRY
This research was conducted because the material absorption capacity needs to be maximized, so it is necessary to make a mining slope geometry with an optimal safety factor value so that there is no potential for landslides in the research area. The method used is the morgenstern price method, this method was chosen because it has considered the stability of moments and forces. The actual slope geometry that has not been tested for safety needs to be changed. The physical and mechanical properties data collection is processed to produce a geometric model with a safety factor in accordance with applicable regulations. The actual slope geometry of the Cijurey block is 20m with a slope of 85o, 8m with a slope of 88o, 5m with a slope of 83o and 4m with a slope of 85o with a safety factor value of 1.01. A geometric change was made with a slope height of 6 m and a ladder width of 3m which was made multi-level with an overall angle of 80o having a safety factor of 1.302 which means that it has met the slope safety criteria.
Copyright (c) 2025 Ahmad Fauzan Haryono https://creativecommons.org/licenses/by-sa/4.0
ANALYSIS OF SEISMICITY AND RETURN PERIOD OF EARTHQUAKES IN SOUTH PESISIR REGENCY WEST SUMATRA PROVINCE USING THE LIKELIHOOD METHOD
The South Pesisir area was one of the areas that was rocked by an earthquake on September 30, 2009. The earthquake that occurred caused damage and loss of life. Based on these conditions, the South Pesisir Regency area was identified as an earthquake-prone area. Therefore, it is necessary to research seismicity and return period in the regency. This research used the statistical likelihood method to determine the accumulated rock stress, seismcity and return period of eartquakes. The data used is earthquake data for the period 1934-2023 with a magnitude ≥4 SR and a depth of ≤300 km. The results of this research provided an overview of the seismicity and return period in the South Pesisir Regency. Seismicity was determined based on rock stress condition (b-value) and on the level seismic activity (a-value). Based on calculations showed that the a-value and b-value for the 20-year and 90-year intervals ranged between 6.16-10.9 and 0.953-2.17, respectively. Earthquakes return periods at intervals of 20 years and 90 years for the magnitude range 4.0-4.4 produced almost the same return period, namely less than one year. Meanwhile, earthquakes with magnitudes of 4.5-6 had recurrence periods ranging from 1 to 63 years.
Copyright (c) 2025 Azmi Asmaul Husna https://creativecommons.org/licenses/by-sa/4.0
CAFFE VISITOR COUNTER SYSTEM USES ANDROID INTEGRATED ULTRASONIC SENSORS AND BLUETOOTH
Developments in the business world are increasingly widespread, especially in the culinary field such as Caffe, almost every city in Indonesia has places to hang out and drink like Caffe. Technological developments here are very important, namely helping cafe owners to check every month how many visitors come to their cafe. In this community service, a tool is made that is useful for counting the number of visitors to the cafe using an ultrasonic sensor that is integrated with Bluetooth. Ultrasonic sensor is a sensor that is used to detect objects with a certain distance measurement. Bluetooth is. In this research, the integration between Bluetooth and ultrasonic sensors is carried out to calculate the number of customers in a cafe. The method used is an experimental method by measuring how much the accuracy value of the ultrasonic sensor counts the number of customers with several repetitions. The research results show that the ultrasonic sensor is most capable of reading data at <= 15 cm, and the readings on the Android via Bluetooth are 100% readable
Copyright (c) 2025 Dewi Lestari https://creativecommons.org/licenses/by-sa/4.0
The IoT-Based Mathematical Pendulum Real Laboratory Tool
Blended learning is a learning approach that combines face-to-face instruction and online learning. In this case, blended learning will be applied to the mathematical pendulum topic through practical experimentation. The mathematical pendulum experiment is a method used to enhance students understanding of the subject matter. This study aims to develop an IoT-based design for a practical mathematical pendulum tool. The research method is based on Research and Development (R&D). The study results in the development of a practical mathematical pendulum tool and control system through the Blynk application. The data displayed on the Blynk application includes the period (t) and the number of oscillations (n). The accuracy of the infrared sensor FC-51 is tested by comparing it with a stopwatch, resulting in a period data accuracy ranging from 96% to 99%. The period data is then used to calculate the acceleration due to gravity (g) with an accuracy ranging from 93% to 97%.
The Effects of Tempering and Cooling Media on The Strength of Hadfield Steel
Hadfield steel is a steel known for its good toughness, but it often experiences damage due to excessive loads. In this study, an analysis of the heat treatment process was conducted on Hadfield steel to enhance its strength through homogenization at a temperature of 850°C and tempering at 600°C with a holding time of 30 minutes, followed by a rolling process with a 20% reduction. The data analysis results indicate that the sample cooled using water as the cooling media produced the most optimum strength. This is evident from its tensile strength value, which reached 941 MPa, with a grain size of 3.51 µm. Although its hardness value 351.98 BHN is slightly lower compared to the sample cooled with air, the difference is not significant. The metallographic observations show that there is a phase change in the sample. Initially, the sample only had an austenite phase during the homogenization process. However, after undergoing tempering, there is a phase change to austenite, ferrite, martensite, and carbide phases. This change will result in an increase in the strength of Hadfield steel.
Analysis of Geothermal Potential Using Gravity Method in Way Ratai Area, Pesawaran Regency, Lampung
Way Ratai, Pesawaran is one of the areas in Lampung that has a surface manifestation, in the form of geothermal potential. Based on data from the Directorate of Geothermal in 2017, Way Ratai has a potential of more than 330 MW with the manifestation of hot springs and hot steam. This study aimed to determine the distribution of subsurface density of Mount Way Ratai, Pesawaran, Lampung region by using ggmplus satellite gravity data. Based on fault analysis method and 2D forward modeling in Oasis Montaj software. The results showed that the geothermal area of Way Ratai identified 2 types of faults, namely reverse faults and normal fault. Based on the results of forward modeling, subsurface density of Way Ratai area, Lampung offering can be identified at a density of 1.2 gr/cc suspected alteration rocks in the form of clay minerals, density of 1.55 gr/cc suspected sand gravel, density of 1.6 gr/cc suspected Tuff rocks, density of 2.3 gr/cc suspected breccia rocks and conglomerates, density 2.6 gr/cc suspected schist and chert, and density 2.99 gr/cc suspected basalt rocks.
Copyright (c) 2024 Putri Adelia, Suwondo - -, Agustya Adi Martha, Tiara Grace Franzisca
Development of Perovskite Manganate-Based Materials as Microwave Absorbers (A Literature Study)
The 5.0 industrial revolution has led to the rapid development of digital devices and radar detection technology. Electromagnetic (EM) radiation generated by digital devices, such as smartphones, computers, and airplanes, is proven to cause great harm to human health. Manganese perovskite is one material that can produce changes such as its crystal structure, electron transfer, electrical properties, and magnetic properties. Doping applied to manganese perovskite-based materials can induce phenomena such as Colossal Magnetoresistance (CMR) and Magnetocaloric Effect (MCE), giving manganese perovskite-based materials great potential to be used as microwave absorbers. Through this article, the development of various manganese perovskite-based materials as microwave absorbers will be reviewed and summarized. Synthesis methods and microwave absorption mechanisms will also be reviewed. This article focuses on the doping of A-site and B-site manganese perovskite-based materials and their performance in absorbing microwaves. Hopefully, this article can be one of the guidelines for designing new manganese perovskite-based materials, to be applied as microwave absorbers.
Copyright (c) 2024 Amanda Haiqal, Danang Pamungkas Priambodo, Fattah Ardhi Faddakiri
ANALYSIS OF LANDSLIDE POTENTIAL IN GUNUNG OMEH SUB-DISTRICK LIMA PULUH KOTA REGENCY USING HVSR METHOD
On BPBD Lima Puluh Kota designated Gunung Omeh Sub-district as a disaster-prone area due to the detected potential of moving soil. This mobile soil causes gaps in the soil with the potential to continue to move at any time and is exacerbated by unstable soil conditions that cause the risk of landslides. Therefore, there is a need for research in Gunung Omeh sub-district on landslide potential. This research aims to analyse the landslide potential in Gunung Omeh sub-district. Data collection is limited to 9 measurement points using a set of Sysmatrack MAE seismograph sensor type S3S. The data generated is in the form of seismic wave signals which are then processed with the HVSR method using Geopsy software to produce H/V curves with parameters A0 and f0. From these two parameters, the values of soil susceptibility index (Kg) and ground shear strain (γg) are obtained. The results showed that the susceptibility index ranged from 0.26 x 10-6 s2/cm to 16.34 x 10-6 s2/cm and ground shear strain ranged from 1.32 x 10-4 to 2.15 x 10-6. Thus, the highest landslide potential is found at point 6 with the highest susceptibility index of 16.34994479 and ground shear strain of 1.32x10¬4.
Computational Model of Boride Diffusion Layer on the Low Carbon Steel
In this paper, a computation model was used to analysis the growth kinetic of two boride layers FeB and Fe2B on the surface of low carbon steel. St41 one of the low carbon steel was used as the basic sample and given the treatment by adding the powder pack boriding in the temperature of 700, 800, and 9000C for the 8 hours of treatment time. To perform the morphology and dimension of the boride layers used the optical microscope. The computation model based on the diffusion equation from the Fick’s Law and solved under the certain assumptions with the parabolic growth of iron boride. For this study, a numerical method was created to determine the iron borides layer thickness as a function of process parameters (temperature and time).By using the parabolic growth constant it can be determined the diffusion coefficient for the phase of FeB, Fe2B, and diffusion zone. Based on the diffusion coefficient it can be predicted the depth and thickness of borided layer on the surface of St41 low carbon steel
Comparison of Kirchhoff Migration and Reverse Time Migration in the Time Domain: Case Study of Field "Y" North West Java Basin
This study evaluates and compares two seismic migration methods, namely Kirchhoff Migration and Reverse Time Migration (RTM), using 2D seismic data in the North West Java Basin. The main objective of the research is to investigate the relative performance of the two methods in restoring the position of reflectors that have undergone distortion due to the propagation phenomenon of seismic waves. The study involves a detailed analysis and comparison of these methods in terms of accuracy and computational time efficiency. The results show that the Kirchhoff Migration method achieves high accuracy in handling reflectors with significant dip angles. Additionally, this method also demonstrates good computational time efficiency. On the other hand, Reverse Time Migration, although recognized as a sophisticated approach, shows less satisfactory results under the conditions of this study, highlighting its dependence on data complexity and velocity model optimality. This research provides important insights for the appropriate selection of migration methods based on geological characteristics and existing seismic data. Kirchhoff Migration emerges as a superior choice, especially for regions with geological complexity and high dip angles. In conclusion, the selection of migration methods should carefully consider the specific characteristics of the relevant region to achieve optimal results.
Copyright (c) 2024 Omar Moefti, Abdul Haris
Ammonia (NH3) Gas Control System in Chicken Coops Using Fuzzy Logic Based Internet of Things (IoT) Method
Chicken productivity increases every year, resulting in air pollution in the form of NH3 generated by chicken waste, which is felt by the residents living around the chicken coop. The purpose of this research is to design an ammonia gas control system using Matlab, with the ammonia gas sensor MQ-135 and the humidity sensor DHT11 as parameters, to minimize the ammonia gas levels. This system operates by transmitting information about the condition of ammonia gas levels using a fuzzy logic control system as the technical decision-making mechanism for driving the exhaust fan based on data from the DHT11 and MQ-135 sensors. In this research, the fuzzy logic method was employed to determine the membership functions for the DHT11 sensor (dry, moist, wet) and MQ-135 sensor (normal, moderate, high), resulting in decisions of safe, moderate, and dangerous levels. The data is monitored on a platform through the Blynk app and Thingspeak, thus connecting the Internet of Things (IoT) to the internet network using the NodeMCU ESP8266 as the microcontroller. This research yields an ammonia gas control system that effectively manages air quality affected by chicken waste, with sensor accuracy levels exceeding 97%.
Copyright (c) 2024 Ambran Hartono Hartono
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.
Copyright (c) 2021 Muhammad Nafian, Nanda Ridki Permana
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.
Kapok randu (Ceiba Pentranda) randu (Ceiba pentranda) skin
Copyright (c) 2021 sheilla rully anggita
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.
Copyright (c) 2021 Suleman Mauritz Sihotang
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.
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.
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.
Investigation of Thermal Properties of Half-Heusler Alloy FeVZ (Z= As, P, Sb) within Density Functional 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.