bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Passive Cooling System of Solar Photovoltaic Panel Based on Hybrid Solar Chimney and Ventilator
Authors: Zhang GengE , Misaran Mohd Suffian , Adzrie Mohd , Amaludin Nazrein Adrian , Guramun Stevenson
Published: December 2023

The efficiency of solar photovoltaic (PV) power generation is significantly impacted by factors such as ambient temperature, surrounding wind speed, and the temperature of the solar PV panels. The power generation efficiency of these panels diminishes by approximately 0.5% for each incremental rise in their temperature. To mitigate this effect, two primary methods for cooling solar photovoltaic panels are considered: active and passive cooling techniques. This review paper delves into an extensive body of literature on solar passive cooling systems, highlighting the vital role of passive cooling technology in enhancing the efficiency of solar PV power generation. We investigate the structure and cooling effect of diverse passive cooling systems, with a specific focus on the application of solar chimneys and ventilators in cooling systems for solar PV panels. Our study reveals that solar chimneys, using buoyancy, can decrease the temperature of solar PV panels by as much as 15 degrees, thereby augmenting power generation efficiency. Furthermore, the deployment of ventilator technology can boost the efficiency of solar PV power generation to an impressive 46.54%. In conclusion, this paper proposes the synergistic use of solar chimneys and ventilators to improve solar PV panel efficiency, extend their lifespan, and reduce the environmental impact resulting from inefficient solar PV panels. This comprehensive approach should inform future practices.
Design and Implementation of Device-level Load Dynamic Adjustment System for Electric Vehicles
Authors: Huang Shu , Liu Ze-san , Meng Hong-min , Xu Zhe-nan , Wen Ai-jun , Liu Di
Published: December 2023

The development of electric vehicles is an important means to deal with the energy crisis, relieve environmental pressure, and achieve sustainable development. The rapid growth of electric vehicle ownership brings great challenges to the planning and safe and stable operation of the power system. To ensure the stable operation of the power grid and meet the changing needs of users to the greatest extent in the case of extreme power shortage and demand response, it is necessary to dynamically adjust the power of charging piles according to the actual situation. At present, many operators cannot accurately and dynamically control the power of each charging pile in the station in the face of power limit demand, so they can only turn off some or all charging piles, which not only affects the charging experience of users but also leads to the decline of operators’ reputation and profits. To solve the above problems, this paper proposed a charging load dynamic adjustment system, which uses the TCN model based on similar days to predict the charging load. It proposed a load decomposition algorithm to control the device-level charging load. Experiments show that the load prediction model used in this system has higher accuracy than LSTM, and the load decomposition algorithm can reasonably allocate limited load resources, which means the system can meet the user’s charging demand to the greatest extent while meeting the power limit demand and improve the user experience.
LabVIEW-based servo valve dynamic and static test system
Authors: Ma Donghui , Xing Keli , Mei Pengwei
Published: December 2023

As a key component of the electro-hydraulic servo control system, the electro-hydraulic servo valve’s performance directly affects the stability of the system’s operation. Therefore, according to the company’s requirements, a servo valve testing system was designed based on LabVIEW. Firstly, the hydraulic system was designed according to the dynamic and static testing requirements of the servo valve. Then, the electrical control system and software system were designed based on PLC and LabVIEW. Finally, dynamic and static characteristic tests of the servo valve were conducted on the designed test bench. A flow-pressure dual closed-loop steady-state control method for testing the no-load flow characteristics was proposed, effectively improving the testing accuracy and meeting the company’s requirements.
Operating Performances of the Water-source Heat Pump System Coupled with PV/T Collector for Heating
Authors: Sun Jize , Zhang Yufeng , Zheng Yawen , Ai Dengxin , Li Wen , Wu Wenjun , Zhao Yuetian
Published: December 2023

An energy supply system that can achieve complementary usage of solar and electric energy is the PV/T collector linked water-source heat pump and electric boiler composite system. TRNSYS simulates the system in this study after each piece of equipment is given a mathematical model. The inlet and outlet water temperatures of the evaporator side and condenser side of the water-source heat pump, the inlet and outlet temperatures of the electric boiler, and the inlet and outlet water temperatures of the source side and load side of the thermal storage tank are all examined in order to determine how well the system operates. The findings demonstrate that by warming the water in the water collecting tank, PV/T performs admirably as a low-temperature heat source for the evaporator side of the water-source heat pump. The condenser side, in contrast, consistently produces hot water at 45°C. The load side of the storage tank’s outlet temperature is between 43°C and 45°C, which is sufficient to suit the users’ heating needs. The source side of the storage tank additionally receives 50°C hot water heated by the electric boiler at night.
Minor Defect Location of Power Cable Based on 2nd-order Chebyshev Self-convolution Window
Authors: Chen Bangfa , He Zilan , Liu Yijun , Hu Yupeng
Published: December 2023

Power cable is extremely important to the stability of the power grid. It is often difficult to determine the location of cable minor defects. Based on previous studies, this paper improves a detection method based on the reflection coefficient, which can effectively locate the minor defect. First, the distributed parameter model of cable is established, and the reflection coefficient is obtained. The 2nd-order self-convolution Chebyshev window function having good positioning effects is selected as the preprocessing function for the real part of the reflection coefficient. Then Discrete Fourier Transform is used to obtain the defect location image. The simulation results indicate that the proposed measure can locate the weak defect in the cable well and improve the positioning accuracy, which shows great application potential.
A Precise Calculation Method of Conductor Current Based on FEM
Authors: Sun Zezhong , Yue Yishi , Wang Feng , Liao Zhenyu , Tan Ben , Wang Cheng , Zhao Mian , Yang Teng
Published: December 2023

The demand for electricity in society is increasing. It is necessary to continuously strengthen the construction of transmission capacity. This article establishes a precise calculation method for the current carrying capacity of wires based on finite element analysis, taking into account the aluminum core diameter, steel core diameter, pitch diameter ratio, rotation angle, etc., which has higher calculation accuracy and is suitable for calculating the current carrying capacity in different meteorological environments. It is of great significance for fully tapping the power supply potential of transmission lines and improving the capacity of transmission channels.
The time resolution improvement of Cherenkov-Radiator-Window Photomultiplier tube
Authors: MA Lishuang , Chen LingYue , Huang Guorui , Hu Jun , Han Xiaorou , Hua Zhehao , Huang XianChao , Jin Muchun , Jiang Xiaoshan , Jin Zhen , Liu Shulin , Pan Weiyan , Qian Sen , Ren Ling , Si Shuguang , Sun Jianning , Wei Long , Wu Qi , Wang Tianyi , Wang Xingchao , Wang Yifang , Wang Yingjie , Wang Zhi , Wang Ning , Wu Kai , Yan Xiongbo , Ye Jingbo , Zhang Haoda , Zhang Zhiming ,   the MCP-PMT work group
Published: December 2023

The improvement of time resolution in time-of-flight positron emission tomography (TOF-PET) relies on the development of scintillation materials and photodetectors. With the introduction of Cherenkov TOF-PET, higher requirements have been placed on the intrinsic timing performance of photodetectors. Our team has proposed a Cherenkov Radiator Window Photomultiplier tube (CRW-FPMT) that uses the Cherenkov radiator directly as the light window, which eliminates the boundary between the scintillator and the photodetector for fast time resolution. This paper mainly discusses the factors influencing its time resolution and optimizes it to achieve a single photon time resolution of 27.2 ps.
Fractional advection diffusion asymmetry equation, derivation, solution and application
Authors: Wang Wanli , Barkai Eli
Published: December 2023

The non-Markovian continuous-time random walk model, featuring fat-tailed waiting times and narrow distributed displacements with a non-zero mean, is a well studied model for anomalous diffusion. Using an analytical approach, we recently demonstrated how a fractional space advection diffusion asymmetry equation, usually associated with Markovian Lévy flights, describes the spreading of a packet of particles. Since we use Gaussian statistics for jump lengths though fat-tailed distribution of waiting times, the appearance of fractional space derivatives in the kinetic equation demands explanations provided in this manuscript. As applications we analyse the spreading of tracers in two dimensions, breakthrough curves investigated in the field of contamination spreading in hydrology and first passage time statistics. We present a subordination scheme valid for the case when the mean waiting time is finite and the variance diverges, which is related to Lévy statistics for the number of renewals in the process.
Spatial Patterns of Under-Resourced Neighbourhood Settlements in Sidenrengrappang Regency
Authors: Riyanti R , Wikantari R , Mahyuddin
Published: December 2023

Under-resourced neighbourhood settlements in Sidenreng Rappang Regency, which are growing, need to get the proper treatment, so that its scope does not expand so that it impacts the decline in the quality of the community’s living environment. The direction of development is identified as early as possible. This is seen from the spatial pattern. This study describes and explains the distribution pattern and spatial correlation of Under-resourced neighbourhood settlements in Sidenreng Rappang Regency. The spatial distribution uses the 2014 and 2020 Under-resourced neighbourhood location map overlay method with administrative maps and adds the attribute data on the percentage of Under-resourced neighbourhood Heads of Families (KK) while the spatial autocorrelation uses Moran’s Index, Moran’s scatterplot and Local Indicator Spatial Autocorrelation (LISA). The results showed that Under-resourced neighbourhood settlements in 2014 were concentrated in the city center while in 2020 they expanded to the west, north, east, and south of Sidenreng Rappang Regency. The results of the Moran Index and Moran’s Scatterplot testing show that there is no difference in the spatial distribution pattern of the percentage of Under-resourced neighbourhood households in 2014 and 2020 where there appears to be a spatial grouping (cluster). The results of the LISA analysis show that 13 villages have spatial autocorrelation. This indicates that the handling of Under-resourced neighbourhood settlements by the central and regional governments until 2019 has no impact on reducing the area and percentage of KK Under-resourced neighbourhoods, but instead grows new Under-resourced neighbourhoods and expands to other areas.
Analysis of Land Use Based on Carrying Capacity of Agricultural Land in Bantul Regency
Authors: Prasetya Yudhian Aditya , Salam Muslim , Munir Ahmad
Published: December 2023

Population growth requires expansion of land as a place to grow and develop. If development is not controlled, land conversion can occur for activities that are not in accordance with its function, so that it has an impact on decreasing the carrying capacity of the environment. The environmental carrying capacity of an area is an important factor that must be considered so that the development process carried out can be sustainable. This study aims to determine changes in agricultural land and land carrying capacity in Bantul Regency. The method used is to analyze land change, evaluate land use based on land class and subclass and analyze the carrying capacity of land in Bantul Regency. In formulating these recommendations, several stages were carried out in this research. Geographic analysis is carried out by optimizing Geographic Information System (GIS) applications to map land conditions including an assessment of land use changes over several years.
Analysis of Thermal Condition of Classrooms in Suburban Area During Corona Virus Desease using Adaptive Method
Authors: Mulyadi R , Hamzah B , Bangsawan N J , Kusno A , Ishak M T , Taufik Y R F , Syukri M R , Bachtiar A A F , Nurhasanah  , Duminggu P A
Published: December 2023

This article addresses the influence of a classroom’s thermal environment on the thermal comfort of the student when windows and vents are wide open during a pandemic, following Corona Virus Desease regulations. This research was conducted quantitatively by measuring the classrooms’ thermal environments from 08:00 to 13:00 at a suburban high school. The findings indicate that the classroom’s average air temperature (Ta) was 29.80°C, with an average relative humidity (RH) of 67.71%, an average airflow velocity (V) of 0.05m/s, an average Mean Radiant Temperature (MRT) of 29.67°C, and an average operating temperature (Top) of 29.72°C. An analysis was conducted using the web-based CBE Thermal Comfort Tool with the Adaptive Method, which can analyze the acceptance of thermal conditions based on operative temperature (Top). According to the analysis, it can be concluded that the thermal environment conditions in the morning in a “Comfortable” condition based on the ASHRAE-55 scale with the operative temperature (Top) are 27.37°C, the airflow speed (V) is 0.3m/s, and the prevailing mean outdoor temperature is 29.73°C. However, during the day, the ambient environmental conditions change, and the thermal comfort turns to “Too Warm” due to the operative temperature condition (Top), which is at the highest point of 31.46°C, with a prevailing mean outdoor temperature of 29.73°C, and an airflow speed (V) of 0.3m/s. It can be seen that the condition has not been able to meet the ASHRAE-55 standard, both in the 80% acceptability limit and the 90% acceptability limit range.
Analysis of Acid Mine Drainage Formation Potential on Coal Stratification in Lamuru Area, Bone Regency, South Sulawesi Province
Authors: Rivai U T , Ramli M , Widodo S
Published: December 2023

The open-pit mining system in coal mines causes the rocks at the mining site to be exposed to the surface so that water and air will react with rocks directly which will cause the formation of acid mine drainage, diverse morphological coditions with many springs and agricultural fields around the research area have an important role that must be maintained so as not to be polluted or damage agricultural land. The purpose of this study was to analyze the presence of sulfide minerals with sulfur content in coal stratification as the initial potential of acid mine drainage, in the lithology of the study area obtained seven lithological samples on coal stratification including overburden, S-01 (siltstone), S-02 (coal seam 1), S-03 (siltstone), S-04 (claystone), S-05 (coal seam 2), S-06 (sandstone) and S-07 (top soil). The results of the X-ray Diffraction (XRD) analysis detected the presence of pyrite minerals, with the results of the analysis of total sulfur ranging from 0.046 to 4.62%, and the results of the analysis of scanning electron microscope (SEM) obtained anhedral, subhedral and framboidal morphology This type of framboidal pyrite is a very fine crystal, very fast to react with air so that this pyrite is believed to be a trigger for the formation of acid mine drainage.
Analysis of Sustainable Drainage System in SMA 4 Area, Jayapura City, Papua
Authors: Riswanto Sigit , Yunianta Andung , Rochmawati Reny , Rumaropen Nimbrot
Published: December 2023

Flooding one of the problems that arise during the rainy season. This is very common in areas with tropical climates, where during the dry season it can be very dry and lack of water, but during the rainy season it is abundant with water and at worst a disaster can occur. Runoff and inundation a usually problem in Jayapura City, with hill topography that tends the large, resulting flood and inundation in flat and upstream areas. One the public areas is often affected by runoff or flood and innudation at the SMA 4 area of Jayapura City, where in this area is most important community activity because it is related to educational activities so attention need paid overcome the problems that occur mainly as a result of runoff. Sustainable drainage system application that prioritizes water quality and runoff water quantity management is very important to overcome the problems runoff and innudation. The result study is find a solution to runoff and iinudation. Analysis method useing Hec-Ras application for calculation discharge and channel dimensions using Sustainable Urban Drainage method which is popularly applied in various countries for water quality and runoff quantity management. The researched result are to obtain the maximum rainfall discharge value and runoff design, drainage channel dimensions, and the appropriate sustainable drainage system in SMA 4 area of Jayapura City[1].
Germination of Cotyledonary Somatic Embryos into Plantlets on Coffea arabica L. of AS2K clone
Authors: Arimarsetiowati R , Prastowo E
Published: December 2023

Andung Sari 2 Klon (AS2K) is an Indonesian superior clone of Arabica coffee (Coffea arabica L.). Coffee plants require two years to complete their life cycle, resulting in genetic development by conventional breeding which is a significant challenge because it takes at least twenty years to produce new varieties that are ready to be marketed. Conventional coffee propagation via shoot cutting is detrimental to the strength and resistance of C. arabica L. cutting roots. Plants lack a taproot, allowing them to collapse easily, and they are frequently attacked by nematodes during the early stages of their growth. Somatic embryogenesis (SE) propagation was possible to produce an excessive number of somatic embryos for the development of plantlets during the availability of elite clones in a field experiment. The purpose of this study was to improve the plant conversion of SE by assessing the effect of different plant growth regulators (PGRs) on plantlet regeneration in AS2K clone Arabica coffee. Cotyledonary embryos were transferred to plantlet regeneration medium, which consisted of a half-strength MS basal medium containing 1 mg/L IBA supplemented with different concentrations (1.0, 3.0, 5.0 mg/l) BAP and (0.5, 1.0, 1.5 mg/l) GA3. Plantlet regeneration was established by using combination of 3 mg/L BAP and 0.5 mg/L GA3 as well as combination of 3 mg/L BAP and 1 mg/L GA3.
Effect of Accelerators on High Early Strength Concrete (HESC) Using High Volume Fly Ash
Authors: Sunarno Y , Rangan P R , Mansyur  , Tumpu M
Published: December 2023

Applying large quantities of fly ash for the production of High Early Strength Concrete (HESC) is a challenge for researchers in the utilization of quality, inexpensive, and environmentally friendly materials. A high volume of fly ash in concrete, however, reduces the initial compressive strength of the concrete. For this reason, it is necessary to use admixture additives in the concrete mixture to get the expected performance. This research seeks to identify the optimal HESC mix design using fly ash 50% of the total cementitious by adding a superplasticizer and accelerator to obtain a high initial compressive strength. Three variations of HESC, namely HESC-12, HESC-14, and HESC-16, were made using a superplasticizer and accelerator with different doses. Each variation uses 12 liters of superplasticizer and different accelerator volumes: 12 liters, 14 liters, and 16 liters. Specimen testing was carried out on fresh and hard concrete. Fresh concrete was subjected to a slump test, whereas hard concrete was subjected to compressive tests at 18 hours, 24 hours, 3 days, and 28 days of age. The average slump flow values for HESC-12, HESC-14, and HESC-16 (cm) were 78, 79.5, and 80, respectively, demonstrating that all HESC samples are classified as self-compacting concrete (SCC). According to the results of density tests conducted on all specimens ranging from 2461 to 2538 kg/m3, all specimens are included in the category of normal-weight concrete. Within the range of 29.8 to 35.3 MPa for the initial compressive strength of HESC at 24 hours of age, it can be concluded that all HESC specimens fulfill the criteria for high early-strength concrete. The addition of the right type and dosage of chemical admixture is a solution to overcome the weakness of applying fly ash in high-early-strength concrete.
Weathered ultrabasic rocks in the Lapaopao, an implication for development of nickel laterite
Authors: Dermawan I , Mawaleda M , Irfan U R
Published: December 2023

The research conducted in the Lapaopao area focuses on analyzing the process of serpentinization in ultramafic rocks and its impact on the formation of nickel laterite. Ultrabasic rocks containing olivine and pyroxene minerals undergo hydrothermal metamorphism, resulting in the formation of serpentine minerals. The research purposed to understand effect of serpentinization process to development of nickel laterite. Various samples were taken on location to see the correlation in both the Lapaopao sub-block and Babarina sub-block. There are two (2) types of samples were taken, including fresh rock (bedrock samples) and laterite samples (limonite and saprolite material). All samples were analyzed using methods such as XRF, thin section, and XRD. Bedrock samples were analyzed using the thin section method, while laterite samples (limonite and saprolite) were analyzed using XRF and X-RD analyzing methods. The serpentinization process in the Babarina sub-block is generally medium to high level, while in the Lapaopao sub-block low to moderate level. The enrichment of nickel (Ni) in the supergene zone is dominantly influenced by Ni’s ability to replace magnesium (Mg) in weathered serpentine minerals.
The Effect of Fertigation System and kitchen waste POC on Paprika Plants
Authors: Driyunitha  , Pakiding Yulius , Kannapadang Sepsriyanti
Published: December 2023

The effort to increase the production of paprika plants is needed in order to supply increasing market demands. The production enhancement can be done through cultivation technology improvement that is the improvement on irrigation system and soil fertility. Fertigation system is a watering application together with fertilizer application. Whereas, the improvement of soil fertility can be done by using kitchen waste POC. The research was carried out in Pangli, Sesean District, Toraja Utara Regency, on February until June 2022. The research is a factorial experiment that is arranged in a Randomized Block Design (RBD), consisting of 8 treatment combinations and repeated 3 times. The first factor is fertigation system that consists of 2 kinds of irrigation systems, namely bulk irrigation system (F1) and drip irrigation system (F2). The second factor is kitchen waste POC that consists of 4 levels of concentration, namely 350 ml/l of water (L1), 400 ml/l of water (L2), 450 ml/l of water (L3), and 500 ml/l of water (L4). The results show that drip fertigation treatment, kitchen waste POC concentration of 450 ml / l water has a significant effect, while the combination of fertigation system treatment and kitchen waste POC concentration only has a significant effect on plant height.
Allocative Efficiency Analysis of Katokkon Chili Production in Tana Toraja and North Toraja Districts
Authors: Lande BPY , Fudjaja L , Hamid N
Published: December 2023

This study aims to measure the allocative efficiency of inputs or production factors in katokkon chili farming with climate-friendly organic farming. This research was conducted in five villages spread across two districts, Tana Toraja and North Toraja, South Sulawesi. This study involved 100 respondents from each village with a census sampling method. The methods used in this study are Cobb-Douglas Stochastic Frontier and allocative efficiency analysis (AEA). The results showed that of the six variables contained in the Cobb-Douglas equation, Land Area (X1), Labor (X2), Compost (X3), Liquid Organic Fertilizer (X4), Vegetable Pesticides (X5), and Farm Capital (X6), only the allocation of farm capital (X6) did not have a significant effect on the production of katokkon chili (Y) in Tana Toraja and North Toraja. Furthermore, the five variables that had a significant effect on the production of katokkon chili were again tested in allocative efficiency analysis, with results showing that the allocative use of Compost, liquid organic fertilizer, and vegetable pesticides was considered efficient or by the usage procedure with the value of NPM / Px = 1. In comparison, the other variables, land area and labor, were allocative, not optimal NPM / Px >1. Hence, increasing land by an average of 72.69 m2 and a workforce of 39.95 HOK was necessary to achieve allocative efficiency.
Analysis of Carbon Footprint in Faculty of Mathematics and Natural Sciences (MIPA), University of Hasanuddin
Authors: Harusi N M R , Zakaria R , Aly S H , Andry A D Z
Published: December 2023

University of Hasanuddin is one of the largest campuses in Sulawesi which has 15 faculties. Faculty of Mathematics and Natural Sciences is one of the faculties that has complex activities in lecture activities and campus operations. All activities that take place produce a carbon footprint that can affect Greenhouse Gases (GHG). Therefore, this study aims to identify activities that generate a carbon footprint and analyze the burden of carbon footprint emissions and see the trend of the relationship between the number of activities and carbon footprint emissions. For data collection techniques by direct observation, interviews and questionnaires which will later be analyzed using the Tier 1 method based on the IPCC 2006. From the analysis results show that the total carbon footprint emission produced at this faculty is 213,778.33 KgCO2-e/year. The activity that produces the most carbon footprint emissions is electricity consumption, which is 206,085.79 KgCO2-e/year with a total consumption of 756,937.99 kWh/year. While the activity that produces the least carbon footprint emissions is the use of paper as much as 921.69 KgCO2-e/year with a total usage of 1,254 kg/year. For the trend of the relationship between the number of activities and carbon footprint emissions, the trend obtained is that the more activities that take place, the higher the carbon footprint produced will also be. However, there is a different phenomenon, namely the value of LPG consumption is less than the value of paper usage as much as 165 kg/year and 1.254 per year. However, the largest carbon footprint emission value is the use of LPG. This happens because the emission factor owned by the LPG source is greater than the paper source. It is hoped that this research can contribute to policy making at the University level. your abstract here…
Harnessing The Potential Of Nanobiopesticides With Plant Extracts: A Review
Authors: Irma Suryani A. , Daud Itji Diana , Melina  , Dewi Vien Sartika , Sari Dian Ekawati , Sulfiani  , Putri Suriati Eka , Hasri
Published: December 2023

This article aims to provide an overview of nanobiopesticides as a promising solution for sustainable and environmentally friendly pest control in agriculture. These formulations combine nanotechnology and biopesticides derived from plant extracts. The synthesis and characterization of plant extract-based pesticide nanoparticles are found to be more effective than using biopesticides alone. In this review, first, we examine the literature on the use of biopesticides, including both plant extract-based pesticides and biopesticides from microorganisms. Moreover, we review several studies on the combination of plant extract-based pesticides and biopesticides to enhance biopesticide efficacy. Finally, we discuss nanobiopesticides in supporting sustainable and environmentally friendly agriculture by utilizing biopesticides based on nanoparticles. Overall, this review highlights the promising prospects of plant extract-based nanobiopesticides and underscores their potential as effective and sustainable alternatives for pest management in modern agriculture.
Detection of subsurface water pipeline under SZJT Track Using Ground-Penetrating Radar Method
Authors: Mariyanto Mariyanto , Parnadi Wahyudi W , Ramadhan Rayhan Farisi , Rochman JPGN , Zulaikah Siti
Published: December 2023

Surabaya’s public facilities and rapid infrastructure development will change the physical environment and require careful attention in all aspects of development. One aspect is the location determination of subsurface objects such as gas pipes, electrical cable lines, and water pipes. Lack of pipeline management and mapping can fail underground pipeline identification during excavation. The subsurface water pipe is one of the most important things to support people’s needs. Knowing the location of these pipes is essential for government agencies in carrying out maintenance, pipeline development, and repair activities. We identified the subsurface water pipeline using the Ground-Penetrating Radar (GPR) method. It is because of a non-destructive working type and very well applied in investigating underground infrastructure with significant electromagnetic contrast with the surrounding soil. We conducted this research around Surabaya Zoo and Joyoboyo Terminal (SZJT) track. We conducted data acquisition with the GPR GSSI SIR-3000 system with a shielded antenna frequency of 270 MHz on 21 measurement lines (JB07 to JB27). The aim is to determine the location, depth, and structure of the subsurface water pipeline at the research location. We processed the measurement data using MatGPR R-3.1 software by adjusting signal position, dc removal, dewow, median filter, inverse amplitude decay, background removal, K-L filter, bandpass filter, and time-to-depth conversion. We conducted 2-D and 2.5-D modeling to visualize the water pipeline. A hyperbolic anomaly, suspected to be a water pipe, is detected from the presence of high amplitude at a depth of 1 – 2 meters, which we saw in almost every line with velocity values from 0.0609 - 0.113 m/ns and dielectric constant value of 7.05 – 24.27. The 2.5-D modeling shows that the water pipeline continues from the research location’s south (Surabaya River) to the north.
Identification of Moho Discontinuity Depth and Subduction Slab in Bengkulu and South Sumatra Region using Receiver Function Method: A Preliminary Result
Authors: Ariyanto P , Al-Hakim A A B , Pranata B , Daryono  , Adi S P
Published: December 2023

Bengkulu and South Sumatra regions are areas with high seismic activity due to faults and subduction zones. This study aims to analyze the depth of the Moho discontinuity layer and subduction slab under 4 BMKG seismic stations that form a perpendicular line of trench in the Bengkulu and South Sumatra areas. The distribution of stations used are Enggano Station (EGSI) in the front arc islands, Manna Station (MNAI) in the front arc basin, Pagar Alam Station (PKSI) in the volcanic-arc zone, and Lahat Station (LHSI) in the proto-volcanic zone. We selected teleseismic earthquake data with a distance of 30°-90° from the stations and magnitudes above 6 (M>6). For the identification of Moho and slab depths, we used analysis of receiver functions with iterative time domain deconvolution and migration of receiver functions with the AK-135 velocity model. The Oceanic Moho layer and the subduction slab under the EGSI Station were identified at depths of 34 km and 23 km respectively, under the MNAI Station the Moho layer and the subduction slab were identified at a depth of 18 km and 87 km respectively, under the PKSI Station the Moho layer and the subduction slab were identified at a depth of 34 km and 129 km respectively, and under the LHSI Station the Moho layer and subduction slab were identified at depths of 35 km and 175 km respectively.
Identification of Geothermal System in Cisolok, West Java based on the Correlation of Gravity Method, ADMT (Active Directory Magnetotelluric), and Drill Log Data
Authors: Puspitasari A S , Permana N R , Gunawan B , Primastika A A
Published: December 2023

Indonesia has 40% geothermal potential of the world’s geothermal potential. One proof of its potential is in Cisolok, West Java. The method used in this study is the gravity method from 2013 GGMPlus satellite with First Horizontal Derivative (FHD) analysis which is correlated with ADMT and drill log data. Based on overlaid between Land Surface Temperature (LST) map and residual anomaly map, Cisolok has a temperature of around 23.8 – 26.5 °C. These correlations describe the normal fault structure in the south that controls the Cisolok geothermal system. The results of the 3D inversion modeling show alternating layers of tuff, tuff breccia and silt as a cap rock with a density contrast of 0 – 0.2 gr/cc at a depth of 0 – 325 m, thick limestone layers with a density contrast of -0.1 – (-0.05) gr/cc at a depth of 325 – 700 m, and a layer of granodiorite rock as an intrusion body with a density contrast of -0.2 – (-0.15) gr/cc at a depth of 700 – 900 m. Based on the results obtained, it can be proven that the gravity method and the ADMT method have a fairly good correlation in geothermal exploration activities.
Identification of Geothermal System Structure Based on Derivative Analysis and 3D Model of Gravity Satellite Data of Mount Rajabasa Area, South Lampung
Authors: Restiana Andini , Zani Fardhan Rafshan , Wardhianty Nabila Firya
Published: December 2023

Indonesia has the second largest geothermal potential with 40% (24 GigaWatt) or 331 points of geothermal reserve locations, this is because Indonesia is traversed by the ring of fire so there are many volcanoes in Indonesia. One of the areas is the Rajabasa Mountain, located in the south of Lampung Regency, with the manifestation of thermal springs and fumaroles. This study aims to provide information related to the existence of geothermal potential using the gravity method, find out the subsurface structure using the First Horizontal Derivative (FHD), Second Vertical Derivative (SVD) methods and conduct 3D modelling. Based on the FHD and SVD analysis, four faults controlling the geothermal system were obtained, distributed in the Northwest – Southeast direction in the form of shear faults, and North-South in the form of normal faults with high anomaly values on residual maps of suspected lava rock intrusions. The 3D modelling results obtained indicate the presence of clay rock which is assumed to be caprock with a density of 2.5 – 2.58 gr/cc at a depth of up to ± 1500 m, and andesite rock which is suspected to be a reservoir with a density of 2.64 – 2.7 gr/cc at a depth of 750 – 2000 m.
The importance of detail fault geometry in modelling the stress change caused by large earthquake: Case Study of 2017 Mw 6.7 Poso earthquake
Authors: Razin T , Rafie M T , Massinai M A , Hamzah M A , Syamsuddin E
Published: December 2023

One of the criteria that can describe the stress condition under which a fault can rupture is the Coulomb Failure Criterion. One technique to calculate the Coulomb Failure Stress (∆CFS) is through the specified orientation approach that requires the strike, dip, and rake of fault geometry parameters. Most studies use planar fault which could degrade the accuracy of the stress calculation. In this study, we present the fault model with variable geometry in order to produce a more detailed stress calculation. We implement the 2017 Mw 6.7 Poso earthquake to model the stress transfer into Poso Fault which has a bent geometry. We compare the stress result with three different cases: planar and curve fault geometries. The result from curve fault geometries is sufficiently different than using the former one. The Coulomb stress distribution is generated in a more detail way when using multi-strike geometry as this parameter is more sensitive to the Coulomb stress change calculation. As demonstrated from this study, fault geometry plays an important role in the Coulomb stress imparted to highly orientated faults.
Oil volumetric calculations of Kujung Formation in the North East Java Basin based on 3D static modelling using geostatistical approach and additional control variable
Authors: Aprina P U , Setiawan M , Miarso T , Dahrin D , Ferucha I
Published: December 2023

Carbonate rock is known as the leading oil and gas reservoir such as Kujung Formation in the North East Java Basin which has been proven to produce fossil energy since 2002. The extended time of oil and gas production needs to be reconsidered by investigating reservoir conditions. The 3D static modelling is constructed by integrating seismic, well log, and geological data using the geostatistical approach to delineate the petrophysical properties which can represent the reservoir heterogeneity. Oil and gas volumetric are calculated by two different techniques. First, the Sequential Gaussian Simulation (SGS) algorithm is used to distribute petrophysical properties, in particular porosity and water saturation with seismic and well log as controlling data. Similar to SGS algorithm, the other method involves AI Cube in co-kriging operation as a secondary variable for generating the porosity ratio. The oil and gas volume estimation using 3D static modelling has been done by integrating co-kriging operation and SGS algorithm establishes higher volumetric value than calculation merely involve SGS algorithm. The higher volumetric value from the combination method is more reliable due to the calculation having various variables that influence the result. The outcome of this research is perchance to beused as field development reference.
Soil dynamic response mapping and vulnerability analysis of earthquake hazard in Banda Aceh using HVSR method
Authors: Fadhilah Firda Haifa , Yudistira Tedi , Tohari Adrin
Published: December 2023

Banda Aceh is a city with a high level of seismicity and earthquake risk. The seismicity level is mainly caused by two Sumatran Fault segments, i.e., the Aceh and Seulimeum Segments. Soft alluvium deposits aggravate the earthquake hazard in Banda Aceh. The presence of soft alluvium layers above the more rigid soil layer will cause earthquake wave amplification. This amplification phenomenon can increase the amplitude and energy of earthquake waves, making the earthquake more destructive.

Therefore, dynamic response mapping and subsurface structure modeling are required to determine the soil characteristics of the research area. Such information is needed for the infrastructure and planning development of Banda Aceh City. This study obtained the subsurface model from microtremor data and a sequence of processing and modeling techniques. The process uses the Horizontal to Vertical Spectral Ratio method (HVSR). The resonance frequency and amplification values are identified from the ratio between the horizontal and vertical spectrum components depicted in the HVSR curves. Based on the obtained results, Banda Aceh has a predominant frequency values range of 0.54-11.72 Hz and an amplification range of 1.22-6.26. Low predominant frequency is mainly located in the study area’s southeast and center, which is associated with large sediment thickness. Meanwhile, high amplification values are mainly located on the study area’s southeast, middle, and northwest sides, which are associated with increased sediment depth and geological features in the form of swamp sediment. Then the value of seismic vulnerability (Kg
) can be obtained based on the predominant frequency and amplification value. In this study, the value of seismic vulnerability ranges between 0.72-31.77 area with relatively high vulnerability values in the middle, southeast, south, and southwest of the study area.
Revealing subsurface structure at the former municipal solid waste disposal site Leuwi Gajah of Cimahi Town by using geophysical data: a preliminary result
Authors: Salam Abdul , Parnadi Wahyudi W.
Published: December 2023

Municipal solid waste disposal site Leuwi Gajah, situated in Cimahi, is near Bandung City. It was a vast open dumping site closed in 2006 due to a harmful geological hazard in 2005, causing hundreds of victims’ deaths. After 16 years of the tragedy, Bandung local government planned for the former municipal solid waste to become a food field with high technology that benefits the community around the area. We applied the Electromagnetic Induction (EMI) technique to image the study area’s subsurface structure as a non-invasive geophysical method. We collected apparent electrical conductivity (ECa) and apparent susceptibility data from the study site in a gridded pattern to map their distribution using EM-38 MK-2 technology. We chose three sites to map those parameter values: site 1, site 2, and site 3. Site 1 is cassava cultivation land by the community. Site 2 is the boundary between former waste and non-waste land, and site 3 is the same land as site 1 but has a steeper slope (20°). The selection of sites 1 and 3 compares land at higher and lower elevations affected by the former landfill landslide. Site 2 shows the difference in characteristics between waste and non-waste land.

Our research in the study area delivers good results. First, we can identify the boundaries of waste and non-waste material, as shown in the low susceptibility value at site 2. This identification is probably related to the thermo-remanent magnetization that results from burning waste. On the other hand, water content influences the distribution of ECa values. Moreover, topography has effects that cause water accumulation in certain areas at sites 1 and 3. These findings recommend using other geophysical methods to detect the boundary between the waste deposit body and underlying bedrock and to characterize the waste body.
Prediction of Compressional Slowness from Conventional Well Log Data using the Gradient Boosting Algorithm
Authors: Utama Widya , Komara Eki , Garini Sherly Ardhya , Rasif Nahari , Insani Alif Nurdien Fitrah , Jabar Omar Abdul , Rosandi Yudi , Hakam Abdul
Published: December 2023

Compressional slowness (DTCO) is the most basic parameter in geophysics, petrophysics, and geomechanics. These parameters can be obtained through the sonic log tool. However, equipment constraints, relatively new technology, and high cost of measurement make the parameters generated by sonic logs unavailable in old wells or wells being developed. Therefore, it is essential to predict sonic logs, especially in the case of compressional slowness prediction. Using machine learning, predictions can be generated by studying data on existing log wells. One of the algorithms that can produce predictions on continuous data, such as log values, is gradient boosting. MAPE and RMSE were used as evaluation metrics. The inputs used are gamma ray log data (GR), density (RHOB), porosity (NPHI), and shear slowness (DTSM). MAPE results show an error value of 12.28% with an RMSE of 10.74, indicating that the predictive model obtained has good results and performance. Using hyperparameter tuning in machine learning can reduce the error rate by 2.29% with faster processing times. In addition, it was found that the quantity of training wells can affect the resulting error value. The existence of this research can help a petrophysicist, geologist, and geophysicist characterize a reservoir with limited data. The use of this method also has the potential to be an alternative solution when sonic log measurements are expensive.
Preliminary Result of Swarm Activities in Toba Region Using Dense Temporary Network
Authors: Nadia Mustika , Simanjuntak Andrean V H , Arifullah A , Sugiyanto Didik , Muksin Umar
Published: December 2023

For the first time, an earthquake swarm occurred in 2021 in Lake Toba (Indonesia), one of the largest calderas in the world. Although the earthquakes were located in the volcanic environment, the swarm activities could be related to the tectonic activities from the Sumatra fault system. The swarm activities occurred at a very shallow depth and were felt with the intensity of II–IV MMI by local people. The objective of this research was to investigate the characteristics of the earthquake swarm in the Toba Caldera from the waveforms recorded by temporary stations in March – June 2021. A total of 26 seismic stations were deployed for two months in May and June 2021. Automatic detection of seismic waves is important because it can be used for earthquake early warning systems and speeds up analysis of origin time, P-, and S arrival times, and earthquake locations. We found characteristics of spectrum waveform from low to high frequency of a non-swarm earthquake, while high frequency seismograms were generated by the swarm earthquake. Furthermore, we successfully captured the hypocentre that was distributed in the SW – NE direction and may figure out the unknown geological system that is responsible for the swarm activities.
Crustal Thickness and Vp/Vs Ratio Determination beneath Tangkuban Parahu Volcano, West Java, Indonesia using Receiver Function Analysis
Authors: Syafawi I. , Nugraha A. D. , Zulfakriza  , Priyono A. , Lesmana A. , Sahara D. P. , Nanang T.P. , Basuki A. , Kristianto K. , Martanto M. , Muttaqy F. , Syahbana D.K. , Puteri M.F.D
Published: December 2023

Tangkuban Parahu, an active stratovolcano located approximately 15 km north of Bandung City in Indonesia, is the focal point of this study. The research aims to examine seismic structures within the crust beneath the Tangkuban Parahu Complex. To accomplish this, a teleseismic receiver function method was employed, utilizing broadband seismic stations along a seismological profile within the Tangkuban Parahu Volcano area. Waveform data were collected during the period from October 24, 2021, to March 31, 2022, for analysis. Various seismic wave phases, including P, Ps, PpPs, and PsPs, were identified in the recorded waveforms, within a time window extending from -2 seconds before the onset of the P-wave to 20 seconds after its onset. The analysis and modelling were conducted using the H-κ stacking receiver function technique. The findings of the H-κ stacking receiver function revealed notable variations in crustal structures, encompassing crustal thickness and the average crustal composition, as indicated by the Vp/Vs ratio, within the Tangkuban Parahu Volcano area. Preliminary results suggest that the crust beneath Tangkuban Parahu, estimated based on data from single seismic station, possesses a thickness of approximately 32.3 km, with a corresponding Vp/Vs ratio of around 1.746.