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2023

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Full-Text Articles in Engineering

Numerical Study Of Owls' Leading-Edge Serrations, Asif Shahriar Nafi, Nikolaos Beratlis, Elias Balaras, Roi Gurka Dec 2023

Numerical Study Of Owls' Leading-Edge Serrations, Asif Shahriar Nafi, Nikolaos Beratlis, Elias Balaras, Roi Gurka

Physics and Engineering Science

Owls' silent flight is commonly attributed to their special wing morphology combined with wingbeat kinematics. One of these special morphological features is known as the leading-edge serrations: rigid miniature hook-like patterns found at the primaries of the wings' leading-edge. It has been hypothesized that leading-edge serrations function as a passive flow control mechanism, impacting the aerodynamic performance. To elucidate the flow physics associated with owls' leading-edge serrations, we investigate the flow-field characteristic around a barn owl wing with serrated leading-edge geometry positioned at 20° angle of attack for a Reynolds number of 40 000. We use direct numerical simulations, where …


Electrochemical Performance Of Porous Ceramic Supported Tubular Solid Oxide Electrolysis Cell, Heng-Ji Wang, Wen-Guo Chen, Zhou-Yi Quan, Kai Zhao, Yi-Fei Sun, Min Chen, Ogenko Volodymyr Dec 2023

Electrochemical Performance Of Porous Ceramic Supported Tubular Solid Oxide Electrolysis Cell, Heng-Ji Wang, Wen-Guo Chen, Zhou-Yi Quan, Kai Zhao, Yi-Fei Sun, Min Chen, Ogenko Volodymyr

Journal of Electrochemistry

Solid oxide electrolysis cell (SOEC) is an efficient and clean energy conversion technology that can utilize electricity obtained from renewable resources, such as solar, wind, and geothermal energy to electrolyze water and produce hydrogen. The conversion of abundant intermittent energy to hydrogen energy would facilitate the efficient utilization of energy resources. SOEC is an all-ceramic electrochemical cell that operates in the intermediate to high temperature range of 500–750 ℃. Compared with traditional low temperature electrolysis technology (e.g., alkaline or proton exchange membrane cells operating at ~100 ℃), the high-temperature SOEC can increase the electrolysis efficiency from 80% to ~100%, providing …


An Ensemble Dnn Model For Automatic Detection Of Covid-19 From Cxr Scans, Hagar Hesham Eldawoudy, Mohamed Abdelazim Mohamed, Eman Abdelhalim Dec 2023

An Ensemble Dnn Model For Automatic Detection Of Covid-19 From Cxr Scans, Hagar Hesham Eldawoudy, Mohamed Abdelazim Mohamed, Eman Abdelhalim

Mansoura Engineering Journal

The new coronavirus 2019 (COVID-19) pandemic has been destructive to human life and has resulted in a significant number of deaths globally. Detecting COVID-19 as early as possible is a critical way to prohibit the virus from quickly passing among people. RT-PCR is a method used for COVID-19 detection, but it is very expensive and isn’t an accurate method due to its sensitivity of 60–70%. For these reasons, deep learning and imaging techniques are combined by doctors, scientific experts, and professionals for accurate and rapid COVID-19 detection. In this work, we propose a stacked ensemble model based on Linear Regression …


Passive Physical Layer Distinct Native Attribute Cyber Security Monitor, Christopher M. Rondeau, Michael A. Temple, Juan Lopez Jr, J. Addison Betances Dec 2023

Passive Physical Layer Distinct Native Attribute Cyber Security Monitor, Christopher M. Rondeau, Michael A. Temple, Juan Lopez Jr, J. Addison Betances

AFIT Patents

A method for cyber security monitor includes monitoring a network interface that is input-only configured to surreptitiously and covertly receive bit-level, physical layer communication between networked control and sensor field devices. During a training mode, a baseline distinct native attribute (DNA) fingerprint is generated for each networked field device. During a protection mode, a current DNA fingerprint is generated for each networked field device. The current DNA fingerprint is compared to the baseline DNA fingerprint for each networked field device. In response to detect at least one of RAA and PAA based on a change in the current DNA fingerprint …


Table Of Contents, The Editors Dec 2023

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Critical Links And Development Trends Of Research On Active Tectonics, Yuan Daoyang, Wang Youlin, Li Shuwu, Wang Wanhe, Li Linyuan, Zou Xiaobo, Wen Yameng Dec 2023

Critical Links And Development Trends Of Research On Active Tectonics, Yuan Daoyang, Wang Youlin, Li Shuwu, Wang Wanhe, Li Linyuan, Zou Xiaobo, Wen Yameng

Coal Geology & Exploration

Following a brief introduction of the general characteristics of active tectonics in China, this study analyzed two new features of large earthquakes with Ms ≥ 7 that have struck continental China since the beginning of the 21st century: (1) Large earthquakes occur primarily in clusters along the boundary fault zone of the Bayanhar active tectonic block—part of the Qinghai-Tibet ateau active tectonic block. (2) Reverse fault-fold earthquakes have occurred multiple times within active basins or at basin-mountain boundaries. In response to the new seismic activity features and the new demand for disaster prevention and mitigation of engineering construction and …


Optimization Of Data Acquisition Parameters For Deep Seismic Reflection Surveys In Complex Terrain, Yan Yunxiang, Li Pei, Zhi Min, Liu Jianda, Wang Zichen, Zhang Ying, Pei Gendi, Li Linyuan, Mou Qi, Jia Jin Dec 2023

Optimization Of Data Acquisition Parameters For Deep Seismic Reflection Surveys In Complex Terrain, Yan Yunxiang, Li Pei, Zhi Min, Liu Jianda, Wang Zichen, Zhang Ying, Pei Gendi, Li Linyuan, Mou Qi, Jia Jin

Coal Geology & Exploration

Fujian, located in the orogen region of the coastal areas of southeast China, exhibits well-developed structures and complex surface conditions, which make deep seismic reflection surveys challenging. In response to the diversity and complexity of seismogeological conditions in Fujian, this study optimized the seismic excitation means based on previous deep seismic surveys. Specifically, the combination of large, medium, and small guns was transitioned into the layout of normal guns (spacing of shot points: 600 m) and large shots (spacing of shot points: 15 km), leading to enhanced folds of large shots. Through simulation analysis, this study calculated the spacing of …


Analogue Modeling Of Love-Type Channel Waves And Their Response To Faults, Liu Qiang, Hu Jiwu, Wang Pan, Shi Xianxin, Jia Qian Dec 2023

Analogue Modeling Of Love-Type Channel Waves And Their Response To Faults, Liu Qiang, Hu Jiwu, Wang Pan, Shi Xianxin, Jia Qian

Coal Geology & Exploration

Owing to its high resolution and low energy attenuation, channel wave-based seismic exploration has been widely applied in the geophysical prospecting of hidden disaster-causing factors in underground coal mines. However, its accuracy fails to meet the requirements of intelligent mine mining presently. At present, the analogue modeling of channel waves mostly focuses on Rayleigh-type channel waves using 2D models, leading to a lack of research on Love-type channel waves. To explore the propagation law of Love-type channel waves, this study investigated the waves in the 3D analogue modeling of channel waves. Firstly, the wave and particle vibration characteristics of Love-type …


New Evidence For Holocene Activity Of The Northern Segment Of The Puqian-Qinglan Fault In Northern Hainan Province, Liu Huaguo, Li Feng, Jia Qichao, Wang Zhicheng, Zhang Pan, Lin Zhen, Zhang Jiehan, Shi Chunhua, Zhang Yanbo, Jia Wei, Li Changlong Dec 2023

New Evidence For Holocene Activity Of The Northern Segment Of The Puqian-Qinglan Fault In Northern Hainan Province, Liu Huaguo, Li Feng, Jia Qichao, Wang Zhicheng, Zhang Pan, Lin Zhen, Zhang Jiehan, Shi Chunhua, Zhang Yanbo, Jia Wei, Li Changlong

Coal Geology & Exploration

The Puqian-Qinglan fault, located in northern Hainan Province, is closely related to the judgment of the seismogenic structure of the Qiongshan M7½ earthquake in 1605. To accurately determine the latest activity characteristics of this fault, this study, adopting artificial shallow seismic exploration with large-tonnage seismic sources combined with small-spacing cross-well stratigraphic correlation, investigated the sedimentary geological conditions of the Quaternary basalt cover and significantly thick marine sand layers in northern Hainan Province through exploration at Qishantou and Dongzhai villages in the Sanjiang Town, Jiangdong New Area, Haikou. Key results are as follows: (1) the Puqian-Qinglan fault dislocates multiple marker …


Activity Variations Of The Shanzuokou-Sihong Fault Within The Jiangsu Segment Of The Tancheng-Lujiang Fault Zone And Their Origins, Zhang Hao, Li Wei, Li Limei, Yan Yunxiang, Jiang Xin, Wang Jinyan, Zhao Qiguang, Gu Qinping, Xu Hangang Dec 2023

Activity Variations Of The Shanzuokou-Sihong Fault Within The Jiangsu Segment Of The Tancheng-Lujiang Fault Zone And Their Origins, Zhang Hao, Li Wei, Li Limei, Yan Yunxiang, Jiang Xin, Wang Jinyan, Zhao Qiguang, Gu Qinping, Xu Hangang

Coal Geology & Exploration

The Shanzuokou-Sihong fault, having undergone the entire evolutionary process of the Tancheng-Lujiang fault zone, exhibits segmentation during the latest activity epoch. Determining the location and origin of its activity segmentation will provide a significant reference for exploring the activity variations of its branch faults and their origins. This study investigated the activity of the Shanzuokou-Sihong fault using a three-dimensional approach combining field geological surveys, shallow seismic exploration, and cross-well stratigraphic correlation. The results show that the Shanzuokou-Sihong fault is a Late Pleistocene active fault on the east side of the North Maling Mountain and a Middle Pleistocene fault in Xinyi …


The Application Of The Opposing Coils Transient Electromagnetic Method And Microtremor Survey Method In Shallow Karst Detection, Zhang Xueliang, Xie Tao, Zhou Wei, Gao Hui, Deng Dong, Qu Jingyi Dec 2023

The Application Of The Opposing Coils Transient Electromagnetic Method And Microtremor Survey Method In Shallow Karst Detection, Zhang Xueliang, Xie Tao, Zhou Wei, Gao Hui, Deng Dong, Qu Jingyi

Coal Geology & Exploration

Concealed karsts frequently lead to disasters such as ground collapse, water reservoir seepage, and tunnel water inrush. Identifying the distribution and development of karsts in advance holds great significance for guiding engineering design and construction in karst areas. Geophysical methods rank among the most effective methods for karst detection. Given the problems of karst development, limited space, and serious electromagnetic interference in the tank farms of the Longkou Port, Shandong Province, this study explored shallow karsts in these farms through the joint application of the opposing coils transient electromagnetic (OCTEM) method and the microtremor survey method. Firstly, surface scanning was …


Activity Of The Liyang-Nandu Fault In Southern Jiangsu, Zhang Shuo, Zhang Ping, Chen Huogen, Xu Shugang, Gong Xulong, Xu Hangang, Li Limei, Feng Wenli, He Zongnan Dec 2023

Activity Of The Liyang-Nandu Fault In Southern Jiangsu, Zhang Shuo, Zhang Ping, Chen Huogen, Xu Shugang, Gong Xulong, Xu Hangang, Li Limei, Feng Wenli, He Zongnan

Coal Geology & Exploration

Located in the central part of the Sunan Modernization Construction Demonstration Area—one of the areas with the densest population and urban areas and the most developed economy in China, the Liyang-Nandu fault is an important concealed fault with a nearly E-W strike in the Yangtze River Delta in eastern China. This fault serves as an important regional geomorphic and neotectonic boundary. However, there is a lack of systematic research on this fault, and its latest activity era is yet to be ascertained. Using seismic exploration P-waves and S-waves and cross-well stratigraphic correlation, this study investigated the spatial distribution and Quaternary …


Table Of Contents, The Editors Dec 2023

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


Application Of High-Precision Lidar Technology In Research On Active Fault-Induced Offset Geomorphic Features - A Case Study Of The Juxian-Tancheng Segment Of The Yishu Fault Zone, Yang Bin, Wang Hualin, Wu Hongbin, Ge Fugang, Zou Hao, Su Sili Dec 2023

Application Of High-Precision Lidar Technology In Research On Active Fault-Induced Offset Geomorphic Features - A Case Study Of The Juxian-Tancheng Segment Of The Yishu Fault Zone, Yang Bin, Wang Hualin, Wu Hongbin, Ge Fugang, Zou Hao, Su Sili

Coal Geology & Exploration

The Tancheng-Lujiang fault zone (also referred to as the TanLu fault zone), one of the most significant large-scale active faults in eastern China, has great seismogenic potential while passing through several cities with the activities and accumulation of human beings. To investigate the geometric distribution and activity characteristics of the TanLu fault zone, this study focused on the Juxian-Tancheng segment of the Yishu fault zone—a part of the TanLu fault zone. Given the vegetation coverage in eastern China, airborne light detection and ranging (LiDAR) and terrestrial laser scanning were employed to collect high-precision topographic data of the Zuoshan (Yibujian), Zhonghuashan, …


Revealing Fine-Scale Crustal Structure And Tectonic Features In The Xiong’An New Area And Its Periphery Using Deep Seismic Reflection Profiling, Yue Hangyu, Wang Kai, Wang Xiaojiang, Zhang Baowei, Zhang Kai Dec 2023

Revealing Fine-Scale Crustal Structure And Tectonic Features In The Xiong’An New Area And Its Periphery Using Deep Seismic Reflection Profiling, Yue Hangyu, Wang Kai, Wang Xiaojiang, Zhang Baowei, Zhang Kai

Coal Geology & Exploration

As an effective method to accurately reveal the deep geological structures and tectonic features of the Earth, deep seismic reflection profiling has been increasingly applied to the exploration of the continental and oceanic crusts, as well as the upper mantle of the lithosphere, making it internationally recognized pioneer technique for deep Earth exploration. This study examined the deep seismic reflection profile spanning across the Xiong’an New Area in Hebei Province, aiming to reveal the crustal structure and tectonic features of the study area. Key findings are as follows: (1) The crust in the study area can be divided into the …


Revealing The Upper Crustal Structure In The Fujian Region Using Deep Seismic Profiling, Li Pei, Ren Congrong, Li Haiyan, Wang Shanxiong Dec 2023

Revealing The Upper Crustal Structure In The Fujian Region Using Deep Seismic Profiling, Li Pei, Ren Congrong, Li Haiyan, Wang Shanxiong

Coal Geology & Exploration

The Fujian region, located along the southeastern margin of the Chinese continent, constitutes an active tectonic belt along the coastal area in southeast China, with complex formation and evolution histories. To understand the characteristics of upper crustal structures and basement structures in the Fujian, this study collected the Pg travel time data from four NE-trending deep seismic sounding (DSS) survey lines in the region. Employing finite-difference tomography, this study obtained the fine-scale velocity structure of the upper crust along the four profiles, revealing the lateral variations in the upper crustal velocity structure, basement structures, and shallow fault characteristics in the …


Dual-Frequency Transmission Radio Wave-Based Exploration Method And Its Application, Fu Xianjie, Hu Ze'an, Wu Rongxin, Li Peng Dec 2023

Dual-Frequency Transmission Radio Wave-Based Exploration Method And Its Application, Fu Xianjie, Hu Ze'an, Wu Rongxin, Li Peng

Coal Geology & Exploration

Coal seams can act as the guided wave layers of high-frequency electromagnetic waves, and radio wave perspective technology can be used to detect geological structures within coal seams of a working face. Presently, radio wave perspective methods usually use a single frequency, leading to some problems such as improper frequency selection and limited detection accuracy in the exploration of mining faces. In response, this study developed a dual-frequency transmission radio wave-based exploration method. Based on theoretical analysis, as well as the field strength of dual-frequency perspective and attenuation coefficient, this study derived the calculation formula for the absorption factor γ …


Chromium-Contaminated Sites: Migration Characteristics And Monitoring Using Dual-Frequency Ip Method, Wei Kaiyao, Liu Zhimin, Liang Chen, Zhang Jie, Ma Qiang Dec 2023

Chromium-Contaminated Sites: Migration Characteristics And Monitoring Using Dual-Frequency Ip Method, Wei Kaiyao, Liu Zhimin, Liang Chen, Zhang Jie, Ma Qiang

Coal Geology & Exploration

Given that the migration process of chromium-contaminated sites is subjected to various uncertainties, it is difficult to investigate the migration characteristics and explore the monitoring process using experiments. Based on the basic law of groundwater flow and the migration mechanisms of pollutants, this study conducted a simulation analysis of the migration characteristics of static chromium contamination sources and the law of changes in the migration characteristics using the COMSOL software. Then, this study verified the reliability and accuracy of numerical forward simulations through physical simulation experiments on a static soil bin. Specifically, using the model of chromium contamination source migration …


Current States , Prediction And Prevention Suggestions For Water Hazard Accidents In China’S Coal Mines, Sun Wenjie, Li Wenjie, Ning Dianyan, Ren Lingfeng Dec 2023

Current States , Prediction And Prevention Suggestions For Water Hazard Accidents In China’S Coal Mines, Sun Wenjie, Li Wenjie, Ning Dianyan, Ren Lingfeng

Coal Geology & Exploration

At present, the pattern of coal resource development in China has changed, but the water hazard accidents that restrict the safety production of coal mine still occur from time to time. In order to explore the characteristics and laws of water hazard accidents in coal mines in China and scientifically study and judge the evolution trend of water hazard accidents, study was performed in terms of the year, region, accident level and influencing factors of water hazard accidents, with the nationwide water hazard accidents from 2001 to 2022 as the statistical objects. Meanwhile, the Long Short-Term Memory (LSTM) model was …


Advances In Research On Active Faults And Exploration Of Relevant Frontier Scientific Problems, Xu Xiwei, Li Feng, Cheng Jia, Liu Baojin, Chen Guihua, Li Kang, Ren Junjie, Jia Qichao Dec 2023

Advances In Research On Active Faults And Exploration Of Relevant Frontier Scientific Problems, Xu Xiwei, Li Feng, Cheng Jia, Liu Baojin, Chen Guihua, Li Kang, Ren Junjie, Jia Qichao

Coal Geology & Exploration

This study reviewed the approval and initiation processes and major research contents of China's active fault-related projects, such as the urban active fault survey projects, large-scale mapping programs of active faults, and the earthquake hazard assessment of active faults in key earthquake monitoring and prevention areas. By combining the scientific investigation results of the surface rupture zones induced by strong earthquakes over the past 20 years, this study elaborated on significant advances achieved in the following aspects: the survey and positioning techniques for concealed active faults under strong-noise and weak-signal conditions, the quantitative identification techniques for fault activity, theories and …


Theory And Application Of Setback Distance From Active Faults, Wei Leiming, Xu Xiwei, Li Feng, Cao Jun, Ren Junjie, Cheng Jia, Zhang Xianbing, Jia Qichao, Chen Guihua, Wu Xiyan Dec 2023

Theory And Application Of Setback Distance From Active Faults, Wei Leiming, Xu Xiwei, Li Feng, Cao Jun, Ren Junjie, Cheng Jia, Zhang Xianbing, Jia Qichao, Chen Guihua, Wu Xiyan

Coal Geology & Exploration

Determining setbacks from active faults is the “last 1 km” from active fault surveys to their application to seismic disaster mitigation. It is also a technique for blocking the risk sources of earthquake-induced chains of geologic hazards. Field investigations and experimental studies have demonstrated that buildings and structures can be free from catastrophic destruction caused by coseismic ruptures and offset of active faults provided they are kept at a certain finite distance from the active fault traces. Therefore, determining setbacks from active faults serves as an ultimate goal of the surveys and precise localization of active faults. Based on the …


Multipoint Sources-Based High-Resolution Electrical Detection Of The Water-Rich Areas Near Mining Faces Of Coal Mine Roadways, Wu Rongxin, Xu Hui Dec 2023

Multipoint Sources-Based High-Resolution Electrical Detection Of The Water-Rich Areas Near Mining Faces Of Coal Mine Roadways, Wu Rongxin, Xu Hui

Coal Geology & Exploration

To accurately explore the spatial distribution of water-rich areas near mining faces of mine roadways, this study proposed a multipoint sources-based high-resolution electrical detection technology. A multi-channel electrode observation system was arranged behind a roadway mining face, with electrodes at a distance of 1/4 measuring lines behind the mining face as point source electrodes sequentially. Data were collected using a monopole-dipole device, with the obtained apparent resistivity considered the sounding data of multipoint sources-based electrical detection. The images of multipoint sources-based electrical sounding allow for quickly determining the presence of water-rich areas and their locations relative to the mining faces …


Application Of Integrated Geophysical Surveys In The Identification Of Hidden Fire Sources In Spontaneous Combustion Zones In Coal Seams, Ma Zijun, Yang Haiyan, Li Wenyu, Xu Yunlei, He Yunlan, Liu Zhuoming, Li Peng, Huang Jiu Dec 2023

Application Of Integrated Geophysical Surveys In The Identification Of Hidden Fire Sources In Spontaneous Combustion Zones In Coal Seams, Ma Zijun, Yang Haiyan, Li Wenyu, Xu Yunlei, He Yunlan, Liu Zhuoming, Li Peng, Huang Jiu

Coal Geology & Exploration

Spontaneous combustion in coal seams, a factor influencing the development of many mining areas in China, can cause severe coal resource loss and environmental pollution. The positioning and distribution identification of hidden fire sources can provide an important basis for coal mine enterprises to prepare prevention and control measures. They are also a hot research topic and challenge in the field of coal fire disasters. Suitable channels for ventilation and oxygen supply are necessary for spontaneous combustion in coal seams. When the oxidative heat release rate of coals exceeds the heat dissipation rate, coal temperature will rise until the occurrence …


Coal-Based Solid Waste From The Panyi Mine In The Huainan Mining Area: Fine-Scale Chemical Structure And Ecological Risk Assessment Of Heavy Metals, Yin Wenwen, Zhang Liqun, Ding Dan, Shan Shifeng, Chen Yongchun, An Shikai, Zheng Liugen Dec 2023

Coal-Based Solid Waste From The Panyi Mine In The Huainan Mining Area: Fine-Scale Chemical Structure And Ecological Risk Assessment Of Heavy Metals, Yin Wenwen, Zhang Liqun, Ding Dan, Shan Shifeng, Chen Yongchun, An Shikai, Zheng Liugen

Coal Geology & Exploration

The utilization of clean coal-based solid waste is a pressing issue in the ecological construction of mining areas. To address this issue, the key is to ascertain the structures and morphology of heavy metals in coal-based solid waste. This study investigated the coal gangue and fly ash samples from the Panyi Mine in the Huainan mining area, Anhui Province. First, this study characterized the coal-based solid waste using microanalysis methods, such as X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Then, it examined the fine-scale chemical structure and heavy metal dissemination …


Critical Links And Development Trends Of Research On Active Tectonics, Yuan Daoyang, Wang Youlin, Li Shuwu, Wang Wanhe, Li Linyuan, Zou Xiaobo, Wen Yameng Dec 2023

Critical Links And Development Trends Of Research On Active Tectonics, Yuan Daoyang, Wang Youlin, Li Shuwu, Wang Wanhe, Li Linyuan, Zou Xiaobo, Wen Yameng

Coal Geology & Exploration

Following a brief introduction of the general characteristics of active tectonics in China, this study analyzed two new features of large earthquakes with Ms ≥ 7 that have struck continental China since the beginning of the 21st century: (1) Large earthquakes occur primarily in clusters along the boundary fault zone of the Bayanhar active tectonic block—part of the Qinghai-Tibet ateau active tectonic block. (2) Reverse fault-fold earthquakes have occurred multiple times within active basins or at basin-mountain boundaries. In response to the new seismic activity features and the new demand for disaster prevention and mitigation of engineering construction and …


Mechanical Behavior And Failure Response Characteristics Of Hard Sandstones Considering Bedding Dip Angles, Song Zhanping, Liu Hongke, Zheng Fang, Cheng Yun, Sun Yinhao, Song Wanxue Dec 2023

Mechanical Behavior And Failure Response Characteristics Of Hard Sandstones Considering Bedding Dip Angles, Song Zhanping, Liu Hongke, Zheng Fang, Cheng Yun, Sun Yinhao, Song Wanxue

Coal Geology & Exploration

This study focuses on the mechanical behavior and failure responses of hard sandstones considering bedding dip angles. Through uniaxial compression tests of hard sandstones with different bedding dip angles, this study delved into the influence of bedding dip angles on the mechanical behavior of hard sandstones and the relationship between the bedding dip angles and fractal characteristics of hard sandstone fragments. The test results show that bedding dip angles produced negligible effects on the type of the stress-strain curves of hard sandstones. However, low dip angles (0°, 22.5°, and 45°) corresponded to unimodal curves, while high dip angles (67.5° and …


Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, Datu Rizal Asral, Donanta Dhaneswara Dec 2023

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, Datu Rizal Asral, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Hydrocarbon releases might result in serious consequences in various aspects. In addition to the contribution to environmental pollution, repetitive leakages need high repair costs. This study aim is to minimize potential repetitive leakage for other typical 3-phase piping systems. We conducted the risk assessment by adopting Risk Based Inspection (RBI) API 581 to identify risk level, calculating piping lifetime, recommended inspection plan and mitigations. The most relevant root causes can be obtained through quantitative Fault Tree Analysis (FTA). Observation and investigation was taken from eight 3-phase piping systems that experienced repetitive leakages. It has been found that the risk level …


Characteristics Of Sodium Lithium Titanate Synthesized At Different Solid-State Reaction Temperature For Lithium-Ion Battery Anode, Ilham Nur Dimas Yahya, Nofrijon Sofyan, Deni Shidqi Khaerudini, Gerald Ensang Timuda, Slamet Priyono Dec 2023

Characteristics Of Sodium Lithium Titanate Synthesized At Different Solid-State Reaction Temperature For Lithium-Ion Battery Anode, Ilham Nur Dimas Yahya, Nofrijon Sofyan, Deni Shidqi Khaerudini, Gerald Ensang Timuda, Slamet Priyono

Journal of Materials Exploration and Findings

The effect of sintering temperature on the characteristics of sodium lithium titanate (NaLiTi3O7/NaLTO) synthesized at different solid-state reaction temperature and its performance as lithium-ion battery anode has been investigated. The precursors for the synthesis consisted of LiOH.H2O, TiO2, and NaHCO3. The synthesis was performed via solid-state reaction method. The precursors were mixed and sintered at variation temperatures of 900oC, 1000oC, and 1100oC for 2 hours under atmosphere condition. The final product was characterized using X-ray diffraction (XRD) and particle size analyzer (PSA). The XRD …


Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj Dec 2023

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj

Journal of Materials Exploration and Findings

The production of metal and alloy products requires the use of heat treatment, when during the heat treatment process, quenching is a crucial step. The quenching medium can be anything from water, a salt bath, oil, air and gas. In a vacuum furnace, pressurized gas, most frequently nitrogen (N2) gas, serves as one of the quenching mediums. One of the drawbacks of the quenching process is the distortion and dimensional change of the parts. This paper aims to investigate the influence of nitrogen gas quenching pressure on the distortion and dimensional change of aerospace actuator gear planet parts …


Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel Dec 2023

Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel

Makara Journal of Technology

Energy consumption in buildings is a crucial concern globally, prompting researchers to explore innovative solutions to mitigate its impact. This study investigates the optimization of building envelopes and roof shading systems of existing buildings in Indonesia to realize notable energy savings. Multiple scenarios were explored, with modifications to building envelopes and roof shading, highlighting the overall thermal transfer value as a key parameter. Using EnergyPlus simulations, the efficacy of natural ventilation in corridors and roof shading modifications was assessed in reducing energy consumption. The findings revealed that renovating existing buildings by optimization of the building envelope and roof shading by …