Page 1 (data 1 to 30 of 114) | Displayed ini 30 data/page
1 2 3 4 NEXT >>

1	Biophysics and Medical Physics	ABS-9
IMRT Planning Using 5, 7 and 9 Radiation Field Directions for Nasopharyngeal Cancer Cases Lira Senja Alfitra (a), Suwandi (b), Idam Arif (a*) a. FMIPA, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132, Indonesia * idam[at]itb.ac.id b. Instalasi Radioterapi, Rumah Sakit Hasan Sadikin, Jalan Pasteur No.38 Bandung, Indonesia Abstract Nasopharyngeal carcinoma (NPC) is one of the deadliest cancers in the world, including Indonesia. One of the methods to treat NPC is the Intensity Modulated Radiation Therapy (IMRT) technique that uses radiation fields from several directions to kill cancer cells and shrink tumors. With many organs at risk (OAR) around the nasopharyngeal cavity, the technique requires accurate planning using the Treatment Planning System (TPS). The purpose of this study is to analyze the results of treatment planning for nasopharyngeal cancer using IMRT techniques related to the use of different radiation field directions. The study focuses on the distribution of dose in the target tumor and organs at risk around the target. The treatment planning parameters are Dose Volume Histogram (DVH), Conformity Index (CI), and Homogeneity Index (HI). The TPS used was TPS Monaco with the Monte Carlo algorithm and the inverse planning method. Based on DVH, CI and HI parameters, the results of this study indicate that for cases of nasopharyngeal cancer, the most optimal number of radiation field directions to give prescribed doses was in the planning with 9 radiation field directions. It is also indicated that, there was no significant difference in the average dose received by OARs in planning with 7 fields and 9 radiation field directions. In the planning using 5 field directions it appears that most of the OARs received doses above the tolerance limit, while in the planning using 7 and 9 field directions, OARs received doses below the tolerated doses so that they met the permitted treatment requirements. Keywords: Nasopharyngeal Cancer, IMRT, TPS, Radiation Fields, Dose Volume Histogram Share Link | Plain Format | Corresponding Author (Idam Arif)

2	Biophysics and Medical Physics	ABS-12
Analysis of the Effect of Tube Current, Slice Thickness, and Tube Voltage on Ct Scan Image Noise using the Noise Power Spectrum (NPS) Method A Ananda Kirei, R Widita Faculty of mathematics and natural sciences, Bandung Institute of Technology Jalan Ganesha 10, Bandung 40132, Indonesia Abstract This study was conducted to analyze CT scan images in order to determine the effect of tube current, slice thickness, and tube voltage on noise using the Noise Power Spectrum (NPS) method. Moreover, this study was also aimed to identify the optimal range of tube current, slice thickness, and tube voltage values to minimize noise formation in CT scan images while maintaining the safe dose for the patients. The research parameters included variations in tube current values with slice thickness variations, using tube voltages of 80 kV and 120 kV. The tube current (mAs) variations used were 150 mAs, 200 mAs, 250 mAs, 300 mAs, and 350 mAs, while the slice thickness variations were 0.8 mm, 1.6 mm, 3.2 mm, 4.8 mm, and 9.6 mm. A Phillips 16-slice access CT scan with a water phantom was utilized as the material for the research. The obtained image data were analyzed using ImQuest and ImageJ software. The results show that as the variations in tube current (mAs), slice thickness (mm), and tube voltage (mV) increase, the noise values decrease. This was demonstrated by the smallest area under the curve (AUC) values, which were 24.46 variance for the tube current variation at 120 kV and 3.57 variance for the slice thickness variation at 120 kV. Thus, to minimize the noise, it is recommended to increase the tube current, slice thickness, and tube voltage. Keywords: CT scan, Noise, Noise Power Spectrum, Slice thickness, Tube current, Tube voltage. Share Link | Plain Format | Corresponding Author (Anggita Ananda Kirei)

3	Biophysics and Medical Physics	ABS-13
Accuracy and Characterization of Electrocardiographic Signal from Mobile Biomedical Sensor Praditya Rizky Rahmansyah (a), Siti Nurul Khotimah (a*), Freddy Haryanto (a), Ridwan Sofyansyah (b) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung Jalan Ganesha 10, Bandung 40132, Indonesia * nurul[at]itb.ac.id b) PKPN Clinic, Jalan Ciledug 79, Garut 44114, Indonesia Abstract Based on the Global Burden of Disease and the Institute for Health Metrics and Evaluation 2014-2019, heart disease is the highest cause of death in Indonesia. One way to deal with this disease is through early detection by reading the electrical signals of the heart. Therefore, the technology for recording the electrocardiographic signal is developing rapidly. Recently, there have been many uses of biomedical sensors to record the electrical activity of the heart by utilizing internet facilities and without cables. This study discusses the accuracy and characterization of cardiac signals recorded by the portable KardiaMobile 6L against the Fukuda M.E Cardisuny type C100 clinical electrocardiograph (ECG). The data are taken for each patient, with a total of 9 patients using both devices simultaneously. ECG signals from the two devices are digitized using a web plot digitizer with time interval of 0.0001 s to obtain the RR interval values for each lead, except lead III which the amplitude is very low. The clinical ECG produces 6 ECG signals (as short data). Meanwhile, the KardiaMobile produces ECG signals for 30 seconds (as long data- and five sequential ECG signals can be sampled as short data). Accuracy is done through linear regression, percent difference, and root mean squared error (RMSE) for the heart rate (HR) displayed by the two devices and RR interval from ECG signals. They provide excellent goodness of fit measures for the linear regression. The percent difference is still in the reliability of the device. The RMSE is very low. Characterization of ECG signals is done by t-test between two array RR interval data from two leads for the same device. Using KardiaMobile, the RR interval value of short data is not significantly different from long data for a subject with normal sinus rhythm. The RR interval value of long data between two leads is not significantly different, likewise for short data between two leads. Using clinical ECG, the RR interval value of short data between two leads is not significantly different for a subject with normal sinus rhythm. Therefore, KardiaMobile has an accuracy similar with a clinical electrocardiograph in determining HR and is effective for analyzing dynamic changes based on RR intervals. Keywords: Electrocardiographic signals- Accuracy- Mobile biomedical sensor- Clinical ECG- Characterization Share Link | Plain Format | Corresponding Author (Praditya Rizky Rahmansyah)

4	Biophysics and Medical Physics	ABS-14
Analysis of CNR and SNR in cases of breast cancer NAC therapy 18F-Fluorothymidine PET: Result From ACRIN 6688 Yeni Pertiwi1,3, Vepy Asyana1, Freddy Haryanto1 , Deni Hardiansyah2 , Idam Arif1 1 The Department of Physics at the Bandung Institute of Technology 2 The Department of Physics at the University of Indonesia 3 Alinsyirah Institute of Health and Technology Abstract Spatial resolution greatly affects the value of the partial volume effect (PVE). PVE contributes considerable uncertainty in measuring Volume of interest (VOI), significantly affecting dose calculations, diagnostics, and treatment therapy in nuclear medicine. This study aims to analyze the CNR and SNR values &#8203-&#8203-of 18F-FLT PET scan results on the response to breast cancer NAC therapy as a quantitative analysis to improve spatial resolution quality. The image data analyzed results from the protocol from scanning the 18F-FLT PET device: ACRIN 6688. Each patient underwent three scans- 18flt-1 was done before therapy (baseline), and 18FLT-2 was done 5-10 days after completing one cycle of NAC therapy, or called a scan. On initial treatment, 18FLT-3 was performed after the second cycle of NAC therapy and three weeks after surgical resection. CNR and SNR values were analyzed in 5 patients. The results of CNR and SNR measurements were analyzed using the correlation matrix of the effect on the stage of therapy. Research results show the correlation matrix analysis of the mean SNR with the stages of the therapy process. The research shows a strong positive linear relationship between SNR at Baseline and Early Therapy. In contrast, the relationship between SNR at Baseline and Post Therapy is weak, and there is almost no significant correlation. As well as the mean value of CNR shows a strong positive linear relationship between CNR at Baseline and Early Therapy and a fairly strong linear relationship between CNR at Baseline and Post Therapy. Based on the research results, there is a strong positive linear relationship between SNR and CNR at the initial stage of therapy (Baseline and Early Therapy), so this quantitative analysis is considered capable of supporting changes in tumor volume in further studies of increasing spatial resolution. Keywords: Breast Cancer, CNR, SNR, PET/CT Share Link | Plain Format | Corresponding Author (Yeni Pertiwi)

5	Biophysics and Medical Physics	ABS-29
The Effect of the Uncertainty of the Biokinetic Data to the Time-integrated Activity in Thyroid Disease Jaja Muhamad Jabar, Ade Riana, Deni Hardiansyah, Freddy Haryanto, Idam Arief Institut Teknologi Bandung Abstract Accurate calculation of individual time-integrated activity (TIA) is desirable in 131I therapy for thyroid disease. TIA is determined by fitting a mathematical model to the biokinetic data of 131I. This study aimed to investigate the influence of varying levels of uncertainty in the biokinetic data on the accuracy of TIA in thyroid disease. Biokinetic data of 131I in the thyroid was obtained from the publication in (1). were fitted to the biokinetic data in thyroid to obtain reference TIAs (rTIAs). Three uncertainty levels, expressed as fractional standard deviation (FSD), were simulated fifty times and were added to the biokinetic data. The parameters of the exponential function were then re-fitted to the simulated noisy biokinetic data to obtain calculated TIAs (cTIAs). Relative deviations (RD) between cTIAs and rTIAs were calculated to explore the relationship between biokinetic data uncertainty and TIA uncertainty. The uncertainty of biokinetic data positively correlates with the uncertainty of TIA. These findings emphasize the importance of incorporating uncertainty analysis in the calculation of TIAs (and subsequently radiation-absorbed doses) in molecular radiotherapy. Keywords: Time-integrated activity, Thyroid, uncertainty Share Link | Plain Format | Corresponding Author (Jaja Muhamad Jabar)

6	Biophysics and Medical Physics	ABS-32
A Comparative Study of Two Segmentation Methods on Radiomics Feature Robustness in Non-Small Cell Lung Cancer Vepy Asyana (a*,b), Mohammad Haekal (c) Yeni Pertiwi (a), Deni Hardiansyah (d), Sparisoma Viridi (a), Freddy Haryanto (a), Abdul Waris (a) a) Nuclear Physics and Biophysics Research Group, Dept. Of Physics, FMIPA ITB, Bandung 40132, Indonesia *vepyasyana[at]gmail.com b) Department of Physics, Faculty of Sciences and Mathematics, Universitas Riau, Pekanbaru 28293, Indonesia c) Department of Physics, ITS, Surabaya 60111 Indonesia d) Department of Physics, Faculty of Sciences and Mathematics, Universitas Indonesia, Jakarta 40132, Indonesia Abstract Radiomics is a mathematical method to convert digital images into mineable data. The data reflects the distribution of signal intensity, texture, or shape of the signal within a specific volume of interest (VOI) or ROI in an image. Analysis of this data can provide information about the biological characteristics of the tumor, patient prognosis, or response to treatment. It has shown exciting promise for improved cancer decision support from early detection to personalized precision treatment and has the potential to revolutionize cancer prognostication. For radiomics, the segmentation method and its effect on radiomic feature stability is a crucial consideration. This study examines the effect of segmentation methods on the stability of radiomic features in identifying differences between Adenocarcinoma and Squamous cell carcinoma cases. This study used PET scan image data of Non-Small Cell Lung Cancer with indications of Adenocarcinoma and Squamous Cell Carcinoma, respectively 25 patients. This image was obtained from The Cancer Imaging Archive (TCIA), a public imaging data source. The segmentation methods used in this study are threshold and edge detection methods. The dice similarity coefficient (DSC) was calculated to quantify segmentation agreement between different segmentation methods. The impact of segmentation on radiomics features was assessed by intra-class correlation coefficients (ICC) and the coefficient of variance (COV). According to the results, the DSC values showed the biggest difference between threshold and edge detection segmentation methods. Grey-level run-length matrix (GLRLM) was a common radiomics signature extracted by all segmentation methods. Keywords: Radiomics, Non-Small Cell Lung Cancer, PET-Scan Share Link | Plain Format | Corresponding Author (Vepy Asyana)

7	Biophysics and Medical Physics	ABS-33
Exposure Risk Assessment Accepted by Radiation Workers in Bandung: A Retrospective Study Yuanita P. D. Sudarso(a*), Flaviana(a) a) Department of Physics, Faculty of Information Technology and Science, Parahyangan Catholic University, 40141 Bandung, Indonesia Abstract Radiation exposure dose of radiation workers who work with ionizing radiation needs to be analyzed to understand radiations impact on each individual and assess and predict radiation-related risks for developing diseases, such as cancer. Thermoluminescence dosimeters are commonly used to measure radiation exposure doses for workers safely. A retrospective analysis was performed on the radiation exposure doses using thermoluminescence dosimeters for radiation workers in Bandung. In this research, radiation workers being reviewed are workers from the Department of Radiotherapy, radiology, and nuclear medicine, with which the exposure dose will be compared. This research aims to increase awareness among healthcare radiation workers in hospitals to strictly adhere to safety protocols by enhancing radiation protective equipment. Keywords: Radiation exposure- Radiation workers- Thermoluminescence dosimeter Share Link | Plain Format | Corresponding Author (Yuanita Puspita Dewi Sudarso)

8	Biophysics and Medical Physics	ABS-58
Histogram Characteristics Analysis of Mass Objects in Quality-Control Phantom for Mammography Image Quality R. P. Cahyani, R. Widita, F. Haryanto Institut Teknologi Bandung Abstract This study presents a simple approach to objectively evaluate mammography image quality in the context of quality control by analyzing the characteristics of image histograms. The histogram analysis is still in its early stages- therefore, the focus of the analysis is on mass objects. Various values of tube voltage, with a tube current of 100 mAs and Mo/Mo filter, were used as parameters in the study. Tube voltage variations used were 24 kVp, 26 kVp, 28 kVp, 30 kVp, and 32 kVp. The research utilized Siemens Mammomat 3000 Nova mammography device with the Artinis PASMAM Constancy phantom as the research material. Objects of interest in the study were the mass of KP-ACR elements present in the phantom. The acquired image data were analyzed using Fiji and OriginLab software. The analyzed histogram characteristics included FWHM, skewness, and kurtosis. The resulting characteristic values were then compared with object scoring by medical physicists. The conclusions indicate that the FWHM values were approximately in the range of 60-85, 90-115, and 120-150 grey value for objects with score of 0, 0.5, and 1, respectively. However, the skewness and kurtosis values did not exhibit significant characteristics for objects with different score. Keywords: histogram, mammography, mass, quality control Share Link | Plain Format | Corresponding Author (Rahmi Puti Cahyani)

9	Biophysics and Medical Physics	ABS-61
Determination of Fractionation Scheme Based on Repair Effect Using Equivalent Uniform Dose (EUD) Model T.A. Pratista, R. Widita Faculty of Physics, Bandung Institute of Technology Jalan Ganesha 10, Bandung 40132, Indonesia *tiarapratista[at]gmail.com Abstract Radiotherapy treatment planning is required to obtain an optimal balance between delivering a high dose to target volume and a low dose to organ at risks. In this planning, it is also necessary to determine the appropriate fractionation scheme for each patient. One of the commonly used methods to determine the fractionation scheme is calculating the Normal Tissue Complication Probability (NTCP) and Tumor Control Probability (TCP) parameters. In this study, the Equivalent Uniform Dose (EUD) model is used to calculate NTCP and TCP. This model is based on a non-uniform dose distribution that is sensitive to the biological factors of cells. The biological factor examined in this research is the repair effect, which is the ability of cells to repair themselves after being radiated. Thus, the objective of this research is to determine the fractionation scheme based on NTCP calculations using the EUD model while taking into account the repair effect. The data used in this study were obtained from 10 patients with glioblastoma brain cancer in the form of cumulative DVH (dose-volume histogram) and total time of radiation. Based on the NTCP calculations, the average risk of organ complication for each patient appears to be close to zero, with a range of values from 2 x 10-6% to 1 x 10-1%. These results indicate that the treatment planning conducted is proven to be safe and there are no complications for the patients. Furthermore, based on the NTCP and TCP calculations, the best fractionation scheme is hypofractionation, which remains safe while considering the dose limit for each normal organ surrounding the target. Keywords: Equivalent uniform dose- Fractionation scheme- Normal tissue complication probability- Repair effect Share Link | Plain Format | Corresponding Author (Tiara Andrina Pratista)

10	Biophysics and Medical Physics	ABS-63
Monte Carlo Simulation of Neutron Contamination in High Energy Linac Bunker using TOPAS Alwali W Solichin (a*), Anisza Okselia (b), Alfia F Azimah (a), Freddy Haryanto (a) a) Department of Physics, Physics Mathematics and Natural Sciences Faculty, Institut Teknologi Bandung, 40132, Bandung, Indonesia *lattov[at]outlook.com b) RSUP Dr. Hasan Sadikin, 40161, Bandung, Indonesia Abstract The growing number of radiotherapy centres in Indonesia means a more effective and accurate protection measure needs to be implemented. Neutron contamination is one of the side effects of high-energy photon radiation in radiotherapy treatment using linear accelerators. This preliminary study aims to comprehend the neutron dose distribution inside a high-energy linear accelerator bunker. A monte carlo simulation using TOPAS 3.9 will be utilized to determine the neutron contamination in high energy photon radiation. A Siemens Oncor head LINAC will be simulated to generate two phase-space. The first phase space is commissioned above the jaws, and the second phase space is below the MLC for a 10x10 cm field size in 100 SSD. The second phase space will then be used as the beam source in the bunker. The bunker specifications will conform to the IAEA regulations, SRS 147, and NCRP 51 for LINAC with 10 MV energy. Earlier simulation using 18 MV energy showed that the first phase space originated from 107 particles generated 2 x 108 particles, with 104 neutron contamination. The second phase space originated from the first phase space with five times redistribution and generated 7 x 107 particles with 7 x 104 neutron contamination. These results showed that there are significant number of neutron contamination in high energy LINAC. The dose distribution will then be analyzed using the isodose curve using phase space data using 10 MV energy LINAC, due to the commonly used LINAC in Indonesia is at this energy rate. Furthermore, data from a 10 MV LINAC facility will be obtained and compared. This research will be the preliminary study of neutron radiation dose distribution in high-energy LINAC bunker. Keywords: Radiotherapy, Neutron Contamination, Monte Carlo, Radiation Protection Share Link | Plain Format | Corresponding Author (Alwali Walyatalattov Solichin)

11	Biophysics and Medical Physics	ABS-68
Analysis of 70 - 300 MeV Proton Energy on Homogeneous and Inhomogeneous Phantoms Ari Fitria (a), Tony Sumaryada(a), Sitti Yani (a*) Department of Physics, Faculty of Mathematics and Natural Sciences, IPB University Abstract Proton therapy represents an advanced form of radiotherapy employing proton particles to precisely target a designated area while minimizing harm to neighboring tissue. As these proton particles traverse the body, they come to rest at a specific depth, generating what^s known as a Bragg peak. The primary objective of this research is to assess the percentage depth dose (PDD) resulting from proton radiation in both homogeneous and inhomogeneous phantoms. The homogeneous phantom replicates the composition of water, bone, and lungs, while the inhomogeneous phantom comprises a mixture of these materials. To emulate the interaction between the phantom and proton radiation, the study employed the Monte Carlo-based PHITS software. The findings underscore the substantial impact of material density and proton energy on the depth of the Bragg peak. Notably, at an energy level of 70 MeV, the Bragg peak manifested at 3.80 cm for the water phantom, 2.60 cm for the bone phantom, and 15.8 cm for the lung phantom. Furthermore, elevating the proton energy led to a proportionally deeper Bragg peak placement. Keywords: Monte Carlo, PHITS, Proton Therapy Share Link | Plain Format | Corresponding Author (Sitti Yani)

12	Biophysics and Medical Physics	ABS-90
Green-Synthesized Fe3O4/Cdots: A New Potential Applications for Bacteria Detection and Antibacterial Agent Emi Kurnia Sari (a), Rafiqa Wulandani (b), Adhistinka Jiananda (a), Rivaldo Marsel Tumbelaka (a), Harlina Ardiyanti (a)(c), Nurul Imani Istiqomah (a), Lufsyi Mahmudin (b), Edi Suharyadi (a*) (a) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia (b) Department of Physics, Universitas Tadulako, Palu, Indonesia (c) Department of Physics, Institute Teknologi Sumatera, Lampung, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract Due to the widespread of pathogens and infectious diseases, rapid detection and antibacterial agents are needed. Antibacterial nanomaterials have attracted attention due to their advantageous properties and unique mechanisms. Besides, the green route approach to synthesizing nanoparticles has attracted interest due to being environmentally friendly, biocompatible, and nontoxic. In this study, carbon dots (Cdots), a promising antibacterial material, have been combined with the Fe3O4 nanoparticles as the carrier and produce Fe3O4/Cdots nanocomposite via green synthesis for bacteria detection and antibacterial agents. Green synthesis was achieved with Moringa oleifera leaves extract as reducing agent on Fe3O4 and watermelon peel as carbon source on Cdots. X ray diffraction shows a cubic inverse spinel structure of magnetite. The phase composition of the nanocomposites consists of magnetite and carbon. The particle size of nanocomposites is 13.4 nm with semi-spherical morphology and lacks other impurities. The bonding analysis and element composition are consistent with phase composition estimation that confirms the existence of Fe3O4 and Cdots on the nanocomposites. The vibrating sample magnetometer shows the superparamagnetic behavior of the samples. Nanocomposites were used as a photoluminescence sensor to detect Escherichia coli (E. coli) bacteria. The quenching of photoluminescence of the nanocomposite shows an increase in the amount of E. coli bacteria. Furthermore, nanocomposites produce high inhibition zones against E. coli bacteria within 48 hours, offering excellent antibacterial properties. Hence, nanocomposites provide a promising green agent for bacteria detection and antibacterial treatment. Keywords: Green synthesis- Cdots- Fe3O4 nanoparticles- Bacteria detection- Antibacterial agent Share Link | Plain Format | Corresponding Author (Emi Kurnia Sari)

13	Biophysics and Medical Physics	ABS-95
The Concentration Effect on Specific Absorption Rate of Green Synthesized Fe3O4/Mesoporous Silica Nanoparticles for Magnetic Hyperthermia Applications Laeli Alvi Nikhmah, Marhan Ebit Saputra, Nurul Imani Istiqomah, Rivaldo Marsel Tumbelaka, and Edi Suharyadi (*) Department of Physics, Universitas Gadjah Mada, Yogyakarta, Indonesia *Corresponding author: esuharyadi[at]ugm.ac.id Abstract Fe3O4 nanoparticles have been successfully synthesized using green and surface-modified Mesoporous Silica Nanoparticles (MSN). The combination is very promising in magnetic hyperthermia therapy applications because it has biocompatible characteristics and synergy between controlled local heat production and preventing agglomeration. The green synthesis method is known for its environmental friendliness, low toxicity, low cost, and simple process. The X-ray Diffraction (XRD) pattern shows the inverted spinel structure of Fe3O4. After Fe3O4 was coated with MSN, there was a decrease in Fe2O3 phase from 48.9 to 33.8% indicating that MSN played a role in reducing the oxidation process on Fe3O4. Then, the crystallite size decreased from 10.5 to 10.3 nm. Fourier transform infrared (FTIR) spectra confirmed that Fe3O4/MSN was successfully fabricated, indicated by the presence of Fe-O and Si-O-Si functional groups at wave numbers 586 cm-1 and 1041 cm-1, respectively. SEM results showed that Fe3O4/MSN has a homogeneous morphology. Meanwhile, EDX spectra showed the elemental composition of Fe3O4/MSN namely Fe, Si, and O with percentages of 53.5, 41.5, and 5%, respectively. VSM results showed that the saturation magnetization of Fe3O4 and Fe3O4/MSN decreased from 55.3 emu/g to 53.4 emu/g. In contrast, the coercivity increased from 58 to 150 Oe. In addition, we investigated the effect of Fe3O4/MSN mass on the SAR value for magnetic hyperthermia applications. The larger the mass, the smaller the SAR value obtained. The specific absorption rate (SAR) value increases as the applied AC magnetic field strength increases. The SAR value obtained from Fe3O4/MSN nanoparticles is 78.9 to 155.4 mW/g at different magnetic field strengths. Moreover, these results prove that green synthesis of Fe3O4/MSN nanoparticles is a promising combination and has the potential to optimize the performance of magnetic hyperthermia applications in the future. Keywords: Surface modification, Fe3O4/MSN, Green synthesis, Magnetic hyperthermia Share Link | Plain Format | Corresponding Author (Laeli Alvi Nikhmah)

14	Biophysics and Medical Physics	ABS-116
Dielectrophoretic force characteristics toward Lactobacillus casei on an oblique-patterned electrode Khazanna (a), Sri Fitriyani (b), Rini Safitri (a), Kurnia Lahna (a), Elin Yusibani (a), Irwansyah (c), Edwar Iswardy (a*) (a) Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Syiah Kuala, Banda Aceh 23111, Indonesia (b) Department of Dental Materials, Faculty of Dentistry, Universitas Syiah Kuala, Banda Aceh 23111, Indonesia (c) Department of Mechanical Engineering, Faculty of Engineering, Universitas Syiah Kuala, Banda Aceh 23111, Indonesia * edwariswardy[at]usk.ac.id Abstract Dielectrophoresis-based biochips with various microelectrode configurations have been extensively studied within the last five decades. However, wide-field application is still challenging. This study aims to fabricate an oblique-configuration microelectrode and then utilizes to determine the dielectrophoretic (DEP) characteristics of Lactobacillus casei based on the generated non-uniform electric field. The analysis of electric field distribution on microelectrodes was simulated with Quickfield 6.6 student version software. The oblique microelectrodes were fabricated using a copper film on a glass substrate. Meanwhile, testing the DEP characteristics of Lactobacillus casei was carried out by applying a sinusoidal AC signal to the microelectrode. The medium solution was prepared with an electrical conductivity of 0.05 S/m. The results on electric field simulation showed that the strongest electric field was generated on the electrode spacing region, and the weakest electric field was generated on the electrode tip spacing. The testing on the fabricated oblique-patterned microelectrode toward Lactobacillus casei showed that the negative DEP force was observed at the frequency of 60-130 kHz, while the positive DEP force was observed at the frequency of 380-700 kHz at a voltage of 2-6 Vpp. The negative DEP force caused Lactobacillus casei to be pushed toward the weak electric field on the electrode tip space area, and the positive DEP force induced Lactobacillus casei to be attracted toward the strong field on the electrode spacing. In general, the presence of negative and positive DEP phenomena provides a promising opportunity for bioparticle separation applications on the fabricated oblique-patterned microelectrode. Keywords: Dielectrophoresis- Oblique microelectrode- Non-uniform electric field- AC signal- Lactobacillus casei Share Link | Plain Format | Corresponding Author (Edwar Iswardy)

15	Earth and Planetary Sciences	ABS-20
Two-dimensional magnetotelluric inversion using unstructured triangular mesh implemented in Julia Dieno Diba (a), Nurhasan (b*), Makoto Uyeshima(a), and Yoshiya Usui(a) a) Earthquake Research Institute, the University of Tokyo, 1 - 1 - 1 Yayoi, Bunkyo, Tokyo 113-0032, Japan b) Physics Department, Bandung Institute of Technology, Jl. Ganesa No.10, Bandung, West Java 40132, Indonesia *nurhasan[at]itb.ac.id Abstract We have developed a 2-D magnetotelluric inversion code tailored for unstructured triangular meshes, developed using Julia, a high-level, high-performance programming language designed for scientific and numerical computation. The forward modeling engine utilizes a node-based finite element method to solve electromagnetic fields throughout the modeling domain. The inversion process employs the Gauss-Newton optimization algorithm, iteratively updating the model via the minimization of a regularized least-squares objective function. We verified the accuracy of the forward modeling using two reference models and performed a synthetic inversion experiment to validate our inversion method and stress the necessity of accurately handling topography-influenced data. Through its application to constructing an electrical resistivity model beneath the northwestern end of Sumatra Island, Indonesia, we demonstrated the practicality of our code for inverting field datasets. Keywords: Magnetotelluric, 2D Inversion, Resistivity Share Link | Plain Format | Corresponding Author (Nurhasan Nurhasan)

16	Earth and Planetary Sciences	ABS-21
Resistivity Distribution of Lembang Fault Based on Magnetotelluric Data Muhammad Risyad Naufal (a), Nurhasan (a*), Wahyu Srigutomo (a), Enjang jaenal Mustopa (a), Dieno Diba (b), Yasuo Ogawa (c), Qhathrin Nada (a), Randi Rusdiana (a) a) Earth Physics and Complex Systems Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung 40132, Indonesia *nurhasan[at]fi.itb.ac.id b) Earthquake Research Institute, the University of Tokyo, 1 - 1 - 1 Yayoi, Bunkyo, Tokyo 113-0032, Japan c)Volcanic Fluid Research Center, Tokyo Institute of Technology, Tokyo, Japan Abstract An Earthquake is a geological phenomenon that happens due to tectonic activity. One of the causes of earthquakes is due to faults that move continuously. Lembang fault located 15 Km north of Bandung city is one of the potential sources of earthquakes in Indonesia. In this study, the Magnetotelluric method was used to model the subsurface resistivity at the Lembang Fault area. The data acquisition was conducted in 9 points of measurement path, perpendicular to the Lembang Fault. The analysis was performed using apparent resistivity data using three different frequencies which are 115 Hz, 11.2 Hz, and 1.02 Hz and inversion modeling was carried out using the finite element method. The result showed that the apparent resistivity decreases significantly in the area of the Lembang Fault. The inversion results show resistivity contrasts around the LMB02 point that is suspected to be the Lembang Fault. These results are consistent with geological data in the Lembang Fault area. Aside from the LMB02 point, there are also resistivity contrasts around the LMB05 point. However, from a geological perspective, it is not yet known whether the area around the LMB05 point represents a fault or another geological structure. Keywords: Lembang Fault, Magnetotelluric, Earthquake, Inversion Modelling Share Link | Plain Format | Corresponding Author (Muhammad Risyad Naufal)

17	Earth and Planetary Sciences	ABS-35
MASW (Multichannel of Analysis of Surface Waves) Measurements on Very Dense Fill of Freeport Mining G Handayani1 and G Masimuja1 1Laboratory of Earth Physics Bandung Institute of Technology Abstract Abstract. The MASW (Multi-Channel Analysis of Surface Waves) was conducted on fill soil at Tembagapura Freeport Mining. The fill was very dense and is the landfills where people dumped waste disposal like car tire rubber etc. Several attempts were made to make boreholes to collect soil samples and to run SPT (Standard Penetration Test), but they failed. The fill was so dense that the employed drill bits were worn out when penetrating the soil. The MASW team was invited to carry out the measurements and to produce shear wave velocities of the layers, which correspond to SPT Number. The number of measured MASW points was 8 points. They were successfully carried out on the surface of the fill without borings. The offset distance between the hammer blows, and the first geophone was 18 m, and the interval distance between 4.5 Hz geophones was 3 m. The MASW measurements resulted in an average shear velocity of 400 m/s which confirmed the soil was very dense soil. The information regarding the shear wave velocities of the layers was adopted as input of earthquake engineering software to predict the amplification when the earthquake happens. Keywords: MASW, Multi Channel Analysis of Surface Waves, S waves Keywords: MASW, Multi Channel Analysis of Surface Waves, S waves Share Link | Plain Format | Corresponding Author (Gunawan Handayani)

18	Earth and Planetary Sciences	ABS-44
Identification of Shale Gas Existence Based on 2-Dimensional Magnetotelluric Data in the Kutai Basin, East Kalimantan, Indonesia Santi Nanda Putri(a), Shofi Iqtina Hasan(b), Cahyo Aji Hapsoro(a*), Yoyok Adisetio Laksono(a) a) Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jalan Semarang 5, Malang, East Java 65145, Indonesia. b) Center for Geological Survey, Geological Agency of Indonesia, Ministry of Energy and Mineral Resources, Indonesia, Jalan Diponegoro No. 57, Bandung 40122, Indonesia. Abstract Research on unconventional methods in the shale gas exploration process has begun to be developed to meet the demand for oil and natural gas sustainability. The research area is located in the Kutai Basin, East Kalimantan, Indonesia. The current study from Center for Geological Survey show that the Kutai Basin has 46.79 TCF of shale gas potential. The Magnetotelluric (MT) method was applied in this study to describe distribution of subsurface resistivity values. The inversions scheme performed in MT method are 1-dimensional and 2-dimensional inversions. In this study, there are 8 measurement stations in 1 line. The presence of low resistivity values or conductive zones identifies the potential for black shale layers. The potential for shale gas is suspected to be detected at station KT29 which is included in the Pamaluan Formation and at stations KT12, KT31, KT13, and KT15 which are included in the Pulaubalang Formation because it is associated with source rock from petroleum in the Kutai Basin system supported by previous research data. Keywords: Unconventional oil and Gas- Shale Gas- Magnetotelluric- Kutai Basin Share Link | Plain Format | Corresponding Author (Santi Nanda Putri)

19	Earth and Planetary Sciences	ABS-46
Analysis of Two-Dimensional Magnetotelluric Inversion for The Delineation of The Petroleum System in The Kutai Basin, East Kalimantan, Indonesia Achmad Nuril Ichsanul Muttakhin(a), Nimas Nurul Hamidah(b), Cahyo Aji Hapsoro(a*), Siti Zulaikah(a) a) Physics Department, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jalan Semarang 5 Malang, East Java, 65145, Indonesia b) Center for Geological Survey, Geological Agency of Indonesia, Ministry of Energy and Mineral Resources, Indonesia, Jalan Diponegoro No. 57, Bandung 40122, Indonesia Abstract The Kutai Basin in East Kalimantan is known as a potential area for oil and gas exploration. 2-dimensional magnetotelluric (MT) analysis is applied to investigate the geological structure and distribution of subsurface resistivity. This study aims to delineate the petroleum system using MT data and identify zones with potential for accumulation of hydrocarbons. MT data has been collected at several strategic locations in the Kutai Basin, and 2-dimensional cross-sections have been constructed to obtain a vertical resistivity imaging at several depths. In this study there were 9 measurement points located at 1 line. The data is then inverted to obtain a 2-dimensional resistivity model which qualitatively represents the subsurface structure. The results of this study indicate that there is a low resistivity anomaly zone which identifies the presence of source rock with a resistivity value of 1-12 &#61527-m. In this line, it is suspected that the petroleum system that allows trapped hydrocarbons is found in the area below the KT36 and KT13 measurement points. In this area there are folded structures in the form of synclines and anticlines which raise suspicions about the types of traps formed from structural traps. Keywords: Petroleum System- Kutai Basin- Magnetotelluric- Resistivity- 2-Dimensional Share Link | Plain Format | Corresponding Author (Achmad Nuril Ichsanul Muttakhin)

20	Earth and Planetary Sciences	ABS-47
Yield Geomechanical Parameters of Talang Akar Formation Shale for Hydraulic Fracturing Feasibility in Shale gas field development Dwi Tunggal Adiprayanto, Bagus Endar B. Nurhandoko2,3, Edy Sunardy1, Yoga A.1 1)Engineering Geology, Padjadjaran University 2)Mathematic and Natural Sciences Faculty, Institut Teknologi Bandung 3)Rock Fluid Imaging Lab Abstract Indonesia^s shale gas potential is very large since Indonesia has large reserves and wide distribution of oil and gas reservoirs. Shale gas development in Indonesia requires an in-depth and unique study that considers the oil play system in Indonesia is in an active tectonic area instead of a continental play system like in the USA and China. Shale is a rock composed mostly of clay-sized mineral grains and is also called mudstone, a sedimentary rock that usually forms from the compaction of at least 50% silt and clay-sized particles. In nature, this shale combines clay minerals, i.e., illite, smectite, kaolinite, and non-clay minerals, i.e.: silica (Quartz), and carbonates, i.e., calcite and dolomite. Shale gas is a reservoir, caprock, and source rock at once. Shale gas is targeted as a potential gas reservoir of natural gas. The quality of this shale reservoir depends on the thickness, extent of existence, organic content, thermal maturity, depth and pressure, fluid saturation, and permeability. However, this shale has very low permeability, and the economic production requires sophisticated stimulation techniques, namely hydraulic fracturing. This hydraulic fracturing technique requires an in-depth understanding of shale rocks^ subsurface stress tensor, elastic modulus, and failure criteria. The yield strength value is the point of displacement or transition from the elastic zone to the plastic zone of shale rock. This yield strength value determines whether the rock^s fractures will remain open after being injected with proppant sand or closed again after the hydraulic fracturing. The fractures will close when the subsurface^s minimum horizontal stress (SHmin) is greater than the rock^s Yield Strength. The fractures are closed because the proppant sand sink into the shale rock since the shale rock enters the plastic zone. This research shows that the yield strength of the Talangakar shale is higher than the SHmin value in the Beringin field, South Sumatra, Indonesia. Therefore, shale gas development in the Talangakar Formation can be feasibly produced with hydraulic fracturing to enhance reservoir permeability. Keywords: Shale gas, Talang akar, South Sumatera, Geomechanics, Yield parameter Share Link | Plain Format | Corresponding Author (Dwi Tunggal Adi Prayanto)

21	Earth and Planetary Sciences	ABS-62
DIY Photometer Performance Test in Determining Morning Twilight Cahyo Puji Asmoro (a,b*), Judhitira Aria Utama(b), Hana Susanti (b), Dhani Herdiwijaya (a), Mahasena Putra (a) a) Astronomy Postgraduate Program, Institut Teknologi Bandung, Indonesia, *20322005[at]mahasiswa.itb.ac.id b) Physics Study Program, Universitas Pendidikan Indonesia Abstract DIY Sky Quality Meter (SQM) with the name Photometer D.I.Y - CJ^01 has been successfully made, the use of SQM as a photometer is currently a hot topic for astronomical research in terms of measuring sky brightness. The data obtained by the photometer is the value of magnitude per square arc second (mag/sq arc second ~ msas) with a maximum value of 21.7 msas as a quantization of the representation of a very dark sky with the presence of natural airglow then gradually decreases to 16.7 msas when the sky is brighter due to the presence of artificial airglow from lighting like in big cities. This research aims to determine the performance of the name Photometer D.I.Y - CJ^01in measuring the brightness of the sky to determine the morning twilight. The research method used was an experiment with data collection from Photometer D.I.Y - CJ^01 and SQM Unihedron in Cimahi City. Data processing shows that the Photometer D.I.Y - CJ^01 has almost the same performance as the SQM Unihedron where the determination of dawn gives a difference in the value of the sun^s depression angle of -0.09452 degree. Keywords: Photometer, Morning Twilight, DIY Share Link | Plain Format | Corresponding Author (Cahyo Puji Asmoro)

22	Earth and Planetary Sciences	ABS-71
Sanding phenomena vulnerability observations due to CO2 injection at the Air Benakat reservoir in South Sumatra Prasandi Abdul Aziz (a*), Bagus Endar B. Nurhandoko (b), Taufan Marhaendrajana (a), Utjok W. R. Siagian (a), Ratih Pratiwi (b), Maria Cindrawati (b) a) Petroleum Engineering, Faculty of Petroleum and Mining Engineering Institut Teknologi Bandung b) Physics Department, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung *corresponding author: prasandi[at]itb.ac.id Abstract Carbon sequestration using carbon capture storage (CCS) is one of the most important operational activities in the oil and gas industry to reduce greenhouse gas emissions and increase hydrocarbon production. Carbon Capture Utilization & Storage (CCUS) can be utilized for both enhancing oil recovery (CO2-EOR), as well as gas recovery (CO2-EGR) by injecting CO2 into the reservoir. However, the CO2 injection into reservoir rock can raise potential sanding problems in both injection and production wells. The phenomena of sanding may be induced dominantly due to carbonic acid injection in the reservoir. The reaction between CO2 and water will form carbonic acid in the reservoir, which can cause the dissolution of rock minerals, especially CaCO3. We investigated the sanding effect when CO2 was injected into the reservoir using several laboratory-scale measurements and observations on the Air Benakat reservoir sample in South Sumatra. The sanding vulnerability was measured by observing pore structure, changes in elastic properties, and rock strength through Rock Physics and Rock Mechanics measurements. XRD analysis showed the presence of CaCO3 minerals in the Air Benakat sandstone sample, which resulted in the possibility of a chemical reaction of the sample, either matrix or pores. The pore structure dissolution was detected from microscale images when the rock was injected with CO2 dissolved in brine water. The changes in rock^s pores due to the dissolution process were also clearly observed from measurements of the changes in rock mass during the injection process of carbonic acid fluid into rock samples from time-to-time measurement. Keywords: CO2 injection, Sanding phenomena, Air Benakat, South Sumatera Share Link | Plain Format | Corresponding Author (Prasandi Abdul Aziz)

23	Earth and Planetary Sciences	ABS-76
Earthquake Events Detected by Continuous Gravimeters Indra Gunawan, Eko Januari Wahyudi, Susanti Alawiyah, Wawan Gunawan Abdul Kadir Institut Teknologi Bandung Abstract Earthquake monitoring and early warning systems play a critical role in mitigating the impact of seismic events on human lives and infrastructure. Continuous gravimeters, sensitive instruments designed to measure second changes in gravitational forces, have emerged as valuable tools for earthquake detection and monitoring. This abstract reports the significance of continuous gravimeters in detecting earthquake events, highlighting their principle of operation, advantages, and contributions to seismic research. In contrast to traditional seismic sensors, continuous gravimeters offer a unique perspective on seismic activity by detecting mass redistributions resulting from the movement of Earths tectonic plates during an earthquake. This capacity enables them to capture the initial moments of an earthquake, contributing to early warning systems that can provide critical seconds to minutes of advance notice, enhancing preparedness and response efforts. Two earthquake events were detected by the gPhone gravimeters placed in Institut Teknologi Bandung, Ganesha Campus. The sources were known to be 10 km deep below the Cirebon area, 106 km away from the gravity station. It shows that continuous gravimeters have the potential capability to advance earthquake monitoring and early warning capabilities. By offering a complementary approach to seismic sensors, these instruments broaden our understanding of earthquake dynamics and contribute to developing more robust and effective strategies for mitigating seismic hazards. As technology continues to evolve, continuous gravimeters hold promise for revolutionizing our ability to detect and respond to earthquake events, ultimately enhancing global resilience to seismic threats. Keywords: gravity, earthquake, monitoring, early warning, gPhone Share Link | Plain Format | Corresponding Author (Indra Gunawan)

24	Earth and Planetary Sciences	ABS-99
The gravity and magnetic prediction for unique density in small Hill of Limestone of Jatibungkus in Central Java Agus Laesanpura, Warsa, E.J. Wahyudi Institut Teknologi Bandung Abstract The density and succeptibilty of limestone is very distinct relative to the other rocks such as sandstone and Clay. In Jatibungkus the limestone as olistolith hill among the clay is partially exposed and very distinct. The olistolith fragment of limestone of one square km, among the others rock give contraste to the others. This idea is do for prediction the similar object in the other area hence the gross density and succeptibilty could be getting in. The gravity for microgal precision, and magnetic for nTesla precision is acquire for 70 measurement around and in the hill,the elevation of sites is known by precise measurement in several cm closed. The residual gravity separation using free hand method is applicable, as well as interpretation, the rock density and succeptibilty magnetic is also measured in the laboratory. The limestone is recognizing as high gravity anomaly of one mGal and low magnetic anomaly clearly distinct. The result of inverse modeling with density optimum shows that the density and susceptibility of geophysics measurement is closed to rock in laboratory. This result is applied to the other area for the prediction, we expect it for deformed rock. Keywords: Please Just Try to Submit This Sample Abstract Share Link | Plain Format | Corresponding Author (Agus Laesanpura)

25	Earth and Planetary Sciences	ABS-103
Machine Learning Implementation on TTV Analysis using TTVFast Muhammad Isnaenda Ikhsan Institut Teknologi Bandung, Institut Teknologi Sumatera Abstract Exoplanet research has undergone rapid development lately due to the increasing number of space telescopes and satellite surveys launched in recent years. Two missions with the most exoplanet discoveries using transit methods are Kepler and TESS missions. Both missions focused on photometric surveys to detect planets by observing the periodic dimming of a star^s brightness as a planet passes in front of it. There is another method that could take advantage of transit observations called transit timing variation method. By observing the deviation of the transit time of transiting planet we could infer the existence of another body in the system. Performing exoplanet parameter estimation using TTV data is an extensive process. Estimating exoplanet parameters using TTV, we must fit the TTV data using a wide range of parameters using n-body simulation. N-body simulation in this scale is computationally costly. To estimate planet parameters, we need to run thousands of n-body simulations. With the increasing trend of using machine learning methods in the research process, we try to implement the machine learning method to make TTV analysis more effective and efficient. We implement the application of machine learning to n-body simulation using REBOUND and TTVFAST and compare the results. REBOUND is a Python-based library designed for simulating the dynamics of n-body systems, particularly celestial bodies like planets, stars, and other objects that interact gravitationally. While TTVFAST is a modified n-body simulation code that is specifically designed to calculate TTV on transiting planetary systems. We found that TTVFAST is much faster than REBOUND when generating samples for training and testing while still maintaining similar accuracy. Also, the machine learning model generated from both data samples is performed similarly. Keywords: TTV, Machine Learning, Exoplanet Share Link | Plain Format | Corresponding Author (Muhammad Isnaenda Ikhsan)

26	Earth and Planetary Sciences	ABS-106
The Effect of porous media specific surface area on non-Darcy flow behavior using pore scale simulation Yusron Feriadi(a)(b*), Umar Fauzi(a), M Rizqie Arbie(a), Fariduzzaman(c) a) Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology b) Research Center for Hydrodynamics Technology, National Research and Innovation Agency *yusr004[at]brin.go.id c) Directorate of Laboratory Management, Research Facilities and Science Area, National Research and Innovation Agency Abstract The effect of the specific surface area of the 3D image of the beadpack on the permeability value and non-Darcy flow behavior was investigated using direct flow simulation using the finite volume method. Specific surface area variations are carried out by upscaling the original image, so that it directly changes the grain size to several diameter variations including 100 um, 125 um, 150 um, 175 um, and 200 um, without changing the porosity and tortuosity values. In this study, we adopted the PIMPLE algorithm to solve the Navier-Stokes equations, which is a combination of the PISO (implicit pressure with splitting of operator) and SIMPLE (semi-implicit method for pressure-linked equations) algorithms. The simulation results show that the permeability value is inversely proportional to the square of the specific surface area. This relationship is in good agreement with the Kozeny-Carman equation. In addition, based on numerical modeling, it can be concluded that the larger the grain diameter, the faster the flow transition from Darcy to non-Darcy occurs. Keywords: permeability- non-Darcy- pore scale simulation- spesific surface area Share Link | Plain Format | Corresponding Author (yusron feriadi)

27	Earth and Planetary Sciences	ABS-110
Electromagnetic modelling in high noise of low frequency signal Agus Laesanpura(a*), Nindya Ekasuci Larasati(a*), Asep Sugianto(b*), Wahyu Eko Yunian(a*) a) Institut Teknologi Bandungb) b) PSDG Abstract Electromagnetic modelling in high noise areas is a challenging task. One part is the precious data for subsurface reconstruction, the other, the noise will a priori annoy the outcome. Through simulation and an example fact in the field, these two phenomena will be discussed. The simulation will propose the ideal model without and with noise, running on the Bostick inversion. Noise varies several schemas in two types of curve. Occam and Bostick algorithms will be used to run the inversion scheme. The trade of the advantages and disadvantage is the compared to a prior model in the field where Em data and geologic cross section are available. Two scenarios available, one is to use data with treatment using available schema, and the other is to use data by cutting off the noise contaminant segment, and finally to see the resulted through 2D modelling process. The resultant show the model use the ideal signal without noise through inversion resulting is a better than the other with a noisy signal experiencing treatment, notably in level shallow part. The geologic cross section and gravity model is available to support these results Keywords: electromagnetic,modelling Share Link | Plain Format | Corresponding Author (Agus Laesanpura)

28	Earth and Planetary Sciences	ABS-119
Comparison of SRP Effect on LEO and GEO Satellite Nindhita Pratiwi (a,b*), Dhani Herdiwijaya (a), Taufiq Hidayat (a), Muhammad Isnaenda Ikhsan (a,b) a) Department of Astronomy, Institut Teknologi Bandung, Bandung, Indonesia b) Atmospheric and Planetary Science Study Program, Institut Teknologi Sumatera, Lampung Selatan, Indonesia Abstract Solar Radiation Pressure (SRP) is one of the main perturbations that needs to be considered in calculation orbit of satellite precisely. SRP describes the interaction between solar radiation flux and the surface of satellite. SRP is also known as one of the most important non-gravitational force acting on LEO satellites. SRP also influences GEO satellite orbits in semi-major axis and eccentricity variations. This research looks into Telkom-1 and LAPAN A1 satellites, Indonesia^s satellites located in GEO and LEO orbit. Calculation of solar radiation pressure on satellites need data of solar flux, satellite^s geometry, and solar geocentric vectors. Data processing uses Free Flyer and Python. We have compared SRP effect on LEO and GEO satellites. The distance between the two satellites is also increasing, showing that there are some effects of solar radiation pressure. Within a month, the distance between satellites increases up to 7.5 kilometers. Within a year, the maximum value of the distance between satellites is 30 kilometers. Keywords: solar radiation pressure, satellite, orbital parameter, LEO, GEO Share Link | Plain Format | Corresponding Author (Nindhita Pratiwi)

29	Energy and Environmental Physics	ABS-1
The Effect of Baseline Establishment on Energy Savings Estimate in Green Building Certification Fahad Najed (a), Ery Djunaedy (b), Amaliyah Rohsari Indah Utami (a) a) School of Electrical Engineering, Telkom University Jalan Telekomunikasi No. 1, Bandung 40257, Indonesia b) Center of Excellence for High Performance Buildings Jalan Rereng Suliga No. 21, Bandung 40123, Indonesia Abstract Recently, an increasing energy consumption and CO2 emission buildings and construction together are accounted globally for 36% and 37%, respectively. This situation implies that buildings consume over one-third of energy demand and emitter CO2 globally. Hence, energy-efficient practices were applied in green building certification to reduce energy consumption and CO2 emission. Each green building certification follows the energy baseline created to take a step further for better future equipped energy end-use. This research objective explains the comparison of different energy baselines referring to GBCI (Green Building Council Indonesia) and ASHRAE standards. Four buildings using different energy baselines were observed in this research. By integrating energy-efficient practices in green building certification, three energy savings methods were used to calculate different energy baselines, specifically EnergyPlus simulation, worksheet calculation, and EDGE simulation. Through the energy savings method, thus outcome energy savings estimate was obtained. The energy savings estimate in the boxplot graph showed GBCI baseline results in huge savings compared to ASHRAE baseline. Keywords: Energy savings- green building- baseline- Share Link | Plain Format | Corresponding Author (Fahad Najed)

30	Energy and Environmental Physics	ABS-2
Investigation of Sediment Thickness in the Rammang-Rammang Maros Karst Area using Microtremor Method Muhammad Arsyad, Sitti Hasaniyah, Agus Susanto Earth Physics Laboratory, Department of Physics, Faculty of Mathematics and Natural Science, Universitas Negeri Makassar, Kampus UNM Parangtambung Jl. Daeng Tata Raya Makassar 90224, Indonesia Abstract The aims of this study were to analyze the value of dominant frequency and amplification, estimate the thickness of the sediment, and to evaluate the seismic vulnerability of the Rammang-Rammang Maros Karst Area. This work was carried out at the Rammang-Rammang Maros Karst Area, Salenrang and Bontolempangan Village, Bontoa District, Maros Regency, South Sulawesi. Microtremor data were analyzed using the Horizontal to Vertical Spectra Ratio (HVSR) method to obtain the H/V curve representing the dominant frequency and amplification values. The dominant frequency values were obtained in the range from 1.389 to 6.251 Hz. The amplification values were in the range from 0.455 to 3.944. The sediment thickness was obtained in the range from 18.521 to 88.029 m, and the seismic vulnerability was in the range from 0.040 to 5.761. High values of sediment thickness were obtained in riverbank areas, which indicated that the weathering that occurred was caused by weathering of limestone and sedimentation by rivers. Meanwhile, low sediment thickness values were obtained in karst hill areas, indicating that the weathering occurred due to the limestone dissolution process. Based on the seismic vulnerability and amplification, the Rammang-Rammang Maros Karst Area is in a relatively safe zone. Keywords: Rammang-Rammang, dominant frequency, amplification, sediment layer, seismic vulnerability Share Link | Plain Format | Corresponding Author (Muhammad Arsyad)

Page 1 (data 1 to 30 of 114) | Displayed ini 30 data/page
1 2 3 4 NEXT >>

Powered By Konfrenzi Ultimate 1.832M-Build6 © 2007-2025 All Rights Reserved