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Full-Text Articles in Engineering

Air Quality Indexing, Mapping And Principal Components Analysis Of Ambient Air Pollutants Around Farm Settlements Across Ogun State, Nigeria, Funmilola Oyebanji, Godson Ana, Opeyemi Tope-Ajayi, Adebayo Sadiq, Yahaya Mijinyawa Apr 2021

Air Quality Indexing, Mapping And Principal Components Analysis Of Ambient Air Pollutants Around Farm Settlements Across Ogun State, Nigeria, Funmilola Oyebanji, Godson Ana, Opeyemi Tope-Ajayi, Adebayo Sadiq, Yahaya Mijinyawa

Applied Environmental Research

The focus of this study was to portray the spatial pattern of air quality across seasons in the eight sampled farm settlements using air quality indexes and assess the clusters of monitored air pollutants. The concentrations of air pollutants were determined using in-situ portable gas detectors and particulate counter. The AQI for each criteria pollutants (CO, O3, TSP, PM10, SO2, and PM2.5) was calculated using AQI formulae of the United States Environmental Protection Agency and mapped using the Inverse distance weighting (IDW) interpolation method in the Geographic information systems (GIS) environment. Principal component analysis (PCA) was used to group the …


Treatment Of Iron From Groundwater By Ozonation: Influence Of Hardness As A Scavenger, Apiradee Sukmilin, Ratsamee Sangsirimongkolying Apr 2021

Treatment Of Iron From Groundwater By Ozonation: Influence Of Hardness As A Scavenger, Apiradee Sukmilin, Ratsamee Sangsirimongkolying

Applied Environmental Research

This study assesses the efficiency of using ozone technology to treat iron from groundwater while hardness acts as a radical scavenger. Batch experiments were conducted to determine the effects of initial pH 6, 7 and 8, and hardness of 300, 400 and 500 mg L-1 and kinetic analysis. The optimum conditions were found to be initial pH of 8 and hardness of 300 mg L-1. The removal efficiency of iron by ozonation was 99.97%, which was higher than that of air without ozone applied (83.67%). However, the presence of hardness and tert-butanol (TBA) had a negative effect on the …


Source And Distribution Of Polycyclic Aromatic Hydrocarbons (Pahs) In Surface Sediment From Chalong Bay, Phuket, Thailand, Danai Tipmanee, Yada Patchim, Penjai Sompongchaiyakul Apr 2021

Source And Distribution Of Polycyclic Aromatic Hydrocarbons (Pahs) In Surface Sediment From Chalong Bay, Phuket, Thailand, Danai Tipmanee, Yada Patchim, Penjai Sompongchaiyakul

Applied Environmental Research

This study aimed to investigate the spatial distribution and apportionment of potential sources of the 16 US-EPA priority PAHs in surface sediments of Chalong Bay, Phuket, Thailand. A total 28 of sediment samples were collected from areas with high maritime activity in Chalong Bay, subjected to conventional high recovery Soxhlet extraction, purified with SiO2 column chromatography, and quantified by Gas Chromatography-Mass Spectrometry (GC/MS). Total concentration of PAHs (Σ16PAHs) ranged from 31.15 to 1696 ng g−1 dry weight, with an average of 198.2 ± 318.5 ng g−1 dry weight. Binary diagnostic ratios plots were used to distinguish between petrogenic and pyrogenic …


Willingness To Pay For Improving Household Solid Waste Management In Vietnam, Phan C. Chinh, Nguyen T.Q. Hung, Nguyen M. Ky, Nguyen T.L. Ai, Nguyen M. Tam Apr 2021

Willingness To Pay For Improving Household Solid Waste Management In Vietnam, Phan C. Chinh, Nguyen T.Q. Hung, Nguyen M. Ky, Nguyen T.L. Ai, Nguyen M. Tam

Applied Environmental Research

Management of solid waste is a major challenge in urban areas of most parts of the world, especially in developing countries. The study aimed to determine and estimate the willingness to pay (WTP) of the selected households for the improvement of solid waste management in Vietnam. The research evaluated WTP of household solid waste in case studies in Bien Hoa and My Tho cities using contingent valuation method (CVM). The data were collected through a closed-ended questionnaire survey and interviews with 200 households. The results showed that the most willingness to pay was equal to 10,000 and 15,000 VND per …


Current Trends In Steroidal 17Α-Ethynylestradiol (Ee2) Removal From The Environment: A Review, Wasiu A. Abibu, Gafar Bamigbade, Amos O. Kolawole, Taiwo Ajayi, Abdul W. Sakariyau Apr 2021

Current Trends In Steroidal 17Α-Ethynylestradiol (Ee2) Removal From The Environment: A Review, Wasiu A. Abibu, Gafar Bamigbade, Amos O. Kolawole, Taiwo Ajayi, Abdul W. Sakariyau

Applied Environmental Research

Emerging contaminants have posed major environmental and health challenges to human and aquatic lives. They include pharmaceuticals, endocrine disrupting compounds (EDCs), persistent environmental pollutants and many more. EE2 is an example of an endocrine disrupting compounds (EDCs) increasingly gaining acceptance and used to augment the deficiencies of other reproductive hormones. EE2 constitutes environmental nuisance via discharge into aquatic bodies, thus, threatening aquatic lives and resulting in health defects in human. It is worthy of note that previous researchers have channeled their studies to identifying ways of expelling EE2 from the environment. However, they remain persistent in the environment. The current …


Is The Relationship Between Mining And Climate Change Only One-Way? Climate Change Potential Impacts On Mining Activity – Hazards, Risks And Adaptation Measures, Małgorzata Markowska Mar 2021

Is The Relationship Between Mining And Climate Change Only One-Way? Climate Change Potential Impacts On Mining Activity – Hazards, Risks And Adaptation Measures, Małgorzata Markowska

Journal of Sustainable Mining

No abstract provided.


The Level Of Securing Dust Deposits Against The Possibility Of Coal Dust Explosion In The Drilled Dog Headings, Bogdan Malich, Krzysztof Cybulski, Malgorzata Wysocka, Krystian Skubacz, Aneta Michałek, Paweł Urban Mar 2021

The Level Of Securing Dust Deposits Against The Possibility Of Coal Dust Explosion In The Drilled Dog Headings, Bogdan Malich, Krzysztof Cybulski, Malgorzata Wysocka, Krystian Skubacz, Aneta Michałek, Paweł Urban

Journal of Sustainable Mining

The article presents the analysis how the actual coal dust explosion hazard is at the distance of the initial 200 metres of the safety zone maintained along the entire length of driven inclined drift II – face 567 in BRZESZCZE colliery, which was used during realization of the project titled Modelling of the mechanism of explosive coal dust deposition in the vicinity of mined faces in terms of identification, assessment and levelling the possibility of its explosion financed by the National Centre for Research and Development. The mine dust level was between 0.014 kg/m3 and 0.193 kg/m3, …


The Influence Of Pressure Drop On Gas Emissions From A Mining Shaft – An Overview, Paweł Wrona, Zenon Różański, Grzegorz Pach, Adam Niewiadomski, Tomasz Suponik Mar 2021

The Influence Of Pressure Drop On Gas Emissions From A Mining Shaft – An Overview, Paweł Wrona, Zenon Różański, Grzegorz Pach, Adam Niewiadomski, Tomasz Suponik

Journal of Sustainable Mining

Climate change can make an impact on the mining sector and post-mining sites. Among others, extreme weather events are connected with sudden and deep pressure drops which lead to gas emissions from an underground space to the surface through closed shafts. The tests undertaken in the frameworks of TEXMIN project lead to get measuring data of this phenomenon and will allow validating numerical models for further forecasts and mitigation means. Three examples of the results were presented. They showed that the intensity of pressure drop influences strongly on gas emissions from a closed shaft. Although the pressure drop process should …


The Impact Of Precipitation On State Of The Slopes Surface And Thermal Activity Of The Mine Waste Dump – Preliminary Study, Zenon Różański, Paweł Wrona, Grzegorz Pach, Adam Niewiadomski, Tomasz Suponik, Robert Frączek, Leszek Balcarczyk Mar 2021

The Impact Of Precipitation On State Of The Slopes Surface And Thermal Activity Of The Mine Waste Dump – Preliminary Study, Zenon Różański, Paweł Wrona, Grzegorz Pach, Adam Niewiadomski, Tomasz Suponik, Robert Frączek, Leszek Balcarczyk

Journal of Sustainable Mining

Precipitation, especially with a high intensity, affects the condition of mining waste dumps. The article presents the results of research aimed at determining the impact of rain on water erosion on the slopes of a coal waste dump and its thermal state. Preliminary tests of the condition of two slopes of the coal waste dump in Libiąż (Poland) undertaken in the frameworks of the TEXMIN project was carried out using modern geodesy techniques (low-ceiling photogrammetry and TLS terrestrial laser scanning). The current geometry of the slope surface was faithfully reproduced in the form of a cloud of points with known …


Acknowledge Of Reviewers Mar 2021

Acknowledge Of Reviewers

Journal of Sustainable Mining

No abstract provided.


Fabrication And Characterization Methods Of Self-Cleaning Coatings For Solar Panels Application, Mohammed Khaleel M Alhussain Mar 2021

Fabrication And Characterization Methods Of Self-Cleaning Coatings For Solar Panels Application, Mohammed Khaleel M Alhussain

USF Tampa Graduate Theses and Dissertations

Transparent self-cleaning coatings with superhydrophobic and superhydrophilic behavior are of great interest in a wide range of industrial applications such as automotive, solar panels, windows, and optical devices. Each has its uses, properties, and characteristics. For the use of these coatings on solar panels, certain features are important in maintaining the efficiency of the panels in different weather conditions and reducing the operation and maintenance cost, such as self-cleaning, high transparency, antifouling, anti-fogging, and anti-icing. Herein, we have investigated the fabrication of self-cleaning coatings using two simple methods and ways to improve their characteristics. In the first method, a hydrophobic …


A Dynamic Programming Approach To Determine Optimum Modularity Level In Industrial Packaging, Marshal Louie, Kumar B Mar 2021

A Dynamic Programming Approach To Determine Optimum Modularity Level In Industrial Packaging, Marshal Louie, Kumar B

Journal of Applied Packaging Research

Modular packaging facilitate customization for accommodating variable product sizes in a product family. When determining package sizes for product variability, packaging engineers does not find difficulty to determine package dimension for less product variety whereas if the product variety is more, then determining the dimension of modular package involves complex decision-making and time-consuming process to find the optimal solution. This in turn directly impacts the overall lead time of the supply chain. Thus, in this paper a dynamic programming is developed to determine the quantity and dimension of modular packages for every demand of assorted products sizes. The program helps …


Volcanic Emissions And Atmospheric Pollution: A Study Of Nanoparticles, Erika M. Trejos, Luis F. O. Silva, James C. Hower, Eriko M. M. Flores, Carlos Mario González, Jorge E. Pachón, Beatriz H. Aristizábal Mar 2021

Volcanic Emissions And Atmospheric Pollution: A Study Of Nanoparticles, Erika M. Trejos, Luis F. O. Silva, James C. Hower, Eriko M. M. Flores, Carlos Mario González, Jorge E. Pachón, Beatriz H. Aristizábal

Center for Applied Energy Research Faculty and Staff Publications

The influence of emissions of an active volcano on the composition of nanoparticles and ultrafine road dust was identified in an urban area of the Andes. Although many cities are close to active volcanoes, few studies have evaluated their influence in road dust composition. Air quality in urban areas is significantly affected by non-exhaust emissions (e.g. road dust, brake wear, tire wear), however, natural sources such as volcanoes also impact the chemical composition of the particles. In this study, elements from volcanic emissions such as Si > Al > Fe > Ca > K > Mg, and Si—Al with K were identified as complex hydrates. …


Fluid Dynamics Modeling For Per- And Polyfluoroalkyl Substances Removal In Legacy Fire Suppression Systems, Jacob G. Spaulding Mar 2021

Fluid Dynamics Modeling For Per- And Polyfluoroalkyl Substances Removal In Legacy Fire Suppression Systems, Jacob G. Spaulding

Theses and Dissertations

Legacy per- and polyfluoroalkyl substances (PFASs) exist in the form of aqueous film-forming foams within hangar fire suppression systems throughout the country, posing a threat to both surrounding environments as well as local populations. The United States (US) Department of Defense (DoD), in conjunction with the US Environmental Protection Agency (EPA), is investigating best practices to flush out existing contaminants prior to disposal and replacement with a less environmentally harmful replacement. While current procedures dictate a triple rinse of the entire system to yield contaminant levels acceptable to the DoD, the practice has never truly been tested. Designed as a …


Comparing The Environmental Impacts Of Using Mass Timber And Structural Steel, Khang Hoang Nguyen, Steelee Knight Morgan Mar 2021

Comparing The Environmental Impacts Of Using Mass Timber And Structural Steel, Khang Hoang Nguyen, Steelee Knight Morgan

Construction Management

Although mass timber has seen a gradual rise in demand in the past, there has been a lack of extensive research on the environmental impacts of using mass timber as a primary structural framing material. This paper compares structural steel, and mass timber’s total embodied carbon emissions. Accurate estimates were made using plans and specs for different projects retrieved from semi-structured interviews. The estimates were input through the EC3 Calculator to provide extensive total carbon emissions measurements between each construction material. Using structural steel framing increased the project’s overall environmental impact by roughly 84% compared to using mass timber. The …


Characterization And Analysis Of Bomarc Accident Debris, Aaron J. Heffelfinger Mar 2021

Characterization And Analysis Of Bomarc Accident Debris, Aaron J. Heffelfinger

Theses and Dissertations

Accidents involving nuclear weapons, such as the Boeing Michigan Aeronautical Research Center (BOMARC) accident in 1960, always pose a significant risk of allowing particles composed of nuclear materials to enter the environment. These particles often differ in characteristics and can be of greatly varying sizes. Gamma ray analysis was conducted on the soil sample and radioisotopes within the sample were identified. Two non-destructive methods for locating actinide bearing particles within the sample were testing, resulting in 70 actinide bearing particles ranging from 1-34 microns being identified. These 70 particles underwent both morphological and elemental characterization, indicating uranium and other elements.


Evaluation Of Efficient Water Reuse Technologies For Sustainable Forward Operating Bases, Kelsie L. Crouch Mar 2021

Evaluation Of Efficient Water Reuse Technologies For Sustainable Forward Operating Bases, Kelsie L. Crouch

Theses and Dissertations

A secure water source is essential to the resiliency and readiness of military installations and contingency operation locations, especially those located in the dry climates the US military operates in today. There are multiple issues of concern when identifying water sources, such as security, cleanliness, accessibility, and sustainability. Water resources pose a potential vulnerability to mission readiness in a remote, agile environment, such as a forward operating base (FOB). Having a secure water resource helps facilitate mission readiness in the contingency environment, offering the opportunity to be more resilient and cost-effective. Current water treatment technologies present the possibility to perform …


Conversion From Coal To Natural Gas At Wright Patterson Air Force Base: An Analysis And Case Study, Tyler A. Ferry Mar 2021

Conversion From Coal To Natural Gas At Wright Patterson Air Force Base: An Analysis And Case Study, Tyler A. Ferry

Theses and Dissertations

Over the last 20 years, natural gas has replaced coal as the preferred fossil fuel for heat and power generation across the United States, due to its increased prevalence, lower cost, and reduced environmental impacts. While most conversion decisions are driven by cost savings, proponents of energy transitions often cite emissions reductions as a tangential benefit. Over the same time, climate change and its impact on the environment and society have come to the forefront of scientific inquiry. One example of the transition from coal to natural gas can be found in Dayton, Ohio. Wright Patterson Air Force Base (WPAFB) …


Renewable Energy Generation And Ghg Emission Reduction Potential Of A Satellitewater Reuse Plant By Using Solar Photovoltaics And Anaerobic Digestion, Jonathan R. Bailey, Saria Bukhary, Jacimaria R. Batista, Sajjad Ahmad Feb 2021

Renewable Energy Generation And Ghg Emission Reduction Potential Of A Satellitewater Reuse Plant By Using Solar Photovoltaics And Anaerobic Digestion, Jonathan R. Bailey, Saria Bukhary, Jacimaria R. Batista, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Wastewater treatment is a very energy-intensive process. The growing population, increased demands for energy and water, and rising pollution levels caused by fossil-fuel-based energy generation, warrants the transition from fossil fuels to renewable energy. This research explored the energy consumption offset of a satellite water reuse plant (WRP) by using solar photovoltaics (PVs) and anaerobic digestion. The analysis was performed for two types of WRPs: conventional (conventional activated sludge system (CAS) bioreactor with secondary clarifiers and dual media filtration) and advanced (bioreactor with membrane filtration (MBR)) treatment satellite WRPs. The associated greenhouse gas (GHG) emissions were also evaluated. For conventional …


Construction And Application Of Remote Service Cloud Platform For Mine Water Hazard Prevention And Control, Wang Hao, Dong Shuning, Qiao Wei, Ji Yadong, Zhu Kaipeng, Zhou Zhenfang, Ning Dianyan, Shang Hongbo Feb 2021

Construction And Application Of Remote Service Cloud Platform For Mine Water Hazard Prevention And Control, Wang Hao, Dong Shuning, Qiao Wei, Ji Yadong, Zhu Kaipeng, Zhou Zhenfang, Ning Dianyan, Shang Hongbo

Coal Geology & Exploration

Coal mine water disaster restricts the safe and efficient development of coal resources seriously. Aiming at the typical problems of roof, floor and goaf mine water disaster at present, three aspects of mine water prevention and control in China has been carried out including water hazard assessment, water inflow prediction, water hazard early warning, and water hazard detection and control, etc. However, the intelligence of these prevention and control work is relatively low. In order to solve this problem, this paper developed a multi-data fusion remote service cloud platform for mine water disaster prevention and control combining with the integration …


Table Of Contents, The Editors Feb 2021

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.


The Evolution Difference Of Macromolecular Structures And Its Dynamic Mechanism Of Coal Macerals:Research Status And Prospect, Cao Daiyong, Wei Yingchun, Wang Anmin, Wang Lu, Liu Zhifei, Qin Rongfang, Shu Zhenyu, Chen Gaojian Feb 2021

The Evolution Difference Of Macromolecular Structures And Its Dynamic Mechanism Of Coal Macerals:Research Status And Prospect, Cao Daiyong, Wei Yingchun, Wang Anmin, Wang Lu, Liu Zhifei, Qin Rongfang, Shu Zhenyu, Chen Gaojian

Coal Geology & Exploration

The physical and chemical properties of macerals are important factors affecting the clean and efficient utilization of coal and the physical properties of coal reservoirs. It has been recognized that the essential cause of determining the properties of macerals lies in their macromolecular structure. In order to reveal the evolution characteristics of macromolecular structure of macerals and its controlling factors, the research progresses at home and abroad were summarized and the shortcomings were analyzed from several aspects, such as the chemical and physical structure of macromolecules, the tectonic stress effect on the macromolecular evolution, and the evolution characteristics of macromolecules …


Review On Carbon Neutralization Associated With Coal Geology, Sang Shuxun, Wang Ran, Zhou Xiaozhi, Huang Huazhou, Liu Shiqi, Han Sijie Feb 2021

Review On Carbon Neutralization Associated With Coal Geology, Sang Shuxun, Wang Ran, Zhou Xiaozhi, Huang Huazhou, Liu Shiqi, Han Sijie

Coal Geology & Exploration

Coal-based carbon emissions constitute the largest part of China's total carbon emissions. Reducing coal-based carbon emissions and realizing the efficient, clean and low-carbon utilization of coal are the important ways to achieve the goal of "carbon neutralization". This paper systematically reviews the research fields of coal geology related to carbon neutralization, analyzes the role and application prospects of coal geology in carbon neutrality research and engineering practice, and discusses the development direction of coal geology in the context of carbon neutralization. The following understandings are obtained. Promoting clean coal geology research to advance the efficient and clean combustion of coal. …


Technologies And Prospect Of Geological Guarantee For Intelligent Coal Mining, Dong Shuning, Liu Zaibin, Cheng Jianyuan, Chen Baohui, Dai Zhenhua, Li Dan Feb 2021

Technologies And Prospect Of Geological Guarantee For Intelligent Coal Mining, Dong Shuning, Liu Zaibin, Cheng Jianyuan, Chen Baohui, Dai Zhenhua, Li Dan

Coal Geology & Exploration

Intelligent coal mining is the strategic selection of the coal industry under the new round of technological change. It is the way that must get through to achieve efficient production of coal mine safety. Geological guarantee technologies can provide accurate and reliable geological data for intelligent coal mining. Moreover, it could reduce the occurrence of coal mine production disasters and accidents by effectively detecting hidden geological factors. The development process of coal geological guarantee technologies in China is systematically expatiated, from serving for resource exploration, high-yield and efficient mine construction to serving for safe and efficient production of coal mines, …


Chemical Compositions And Technological Properties Of Low-Rank Coals In The South Shenfu Mining Area: Characteristics, Relationship And Practice, Guo Chen, Wang Shengquan, Shi Qingmin, Qiao Junwei, Li Huantong, Zhang Weiguo, Li Jun, Zhang Chi, Wang Xiaokang, Du Fangpeng Feb 2021

Chemical Compositions And Technological Properties Of Low-Rank Coals In The South Shenfu Mining Area: Characteristics, Relationship And Practice, Guo Chen, Wang Shengquan, Shi Qingmin, Qiao Junwei, Li Huantong, Zhang Weiguo, Li Jun, Zhang Chi, Wang Xiaokang, Du Fangpeng

Coal Geology & Exploration

Coal grading utilization is an essential way to fit its high-efficiency, clean and green development trends. Understanding the basic chemical composition and key technological properties of coal is the basis for achieving grading and qualitative utilization of coal resources. The South Shenfu mining area in Shaanxi Province is rich in coal reserves and it is an important low-rank coal production base in West China. However, it has not been able to achieve the qualitative utilization of coal practically completely for a long time, which restricts the full play of the value of coal resources and the further improvement of coal …


The Characteristics Of Pore Structure And Gas Adsorption For Water-Immersion Coal After Drying, Si Leilei, Xi Yujun, Wang Hongyang, Wen Zhihui, Wei [email protected] Jianping Feb 2021

The Characteristics Of Pore Structure And Gas Adsorption For Water-Immersion Coal After Drying, Si Leilei, Xi Yujun, Wang Hongyang, Wen Zhihui, Wei [email protected] Jianping

Coal Geology & Exploration

In order to investigate the characteristics of pore structure and methane adsorption for water-immersion coal after drying, two coal samples with different ranks were soaked in distilled water for a long time(60 d). Then, the low-temperature N2 adsorption experiments and CO2 adsorption experiments were carried out to investigate the changing rules of pore structure for coal before and after water immersion, and the high-pressure capacity method was used to test the characteristics of methane adsorption. Results showed that the pore volume and specific surface area of coal decreased after water immersion. According to the results of low-temperature N …


Numerical Analysis On Csw Fracturing Behavior Of Coal Seam Under Constraint Of Geological And Engineering Conditions, Qin Yong, Li Hengle, Zhang Yongmin, Zhao Youzhi, Zhao Jincheng, Qiu Aici Feb 2021

Numerical Analysis On Csw Fracturing Behavior Of Coal Seam Under Constraint Of Geological And Engineering Conditions, Qin Yong, Li Hengle, Zhang Yongmin, Zhao Youzhi, Zhao Jincheng, Qiu Aici

Coal Geology & Exploration

As a revolutionary technology for rock stratum reformation, the controllable shock wave(CSW) fracturing technology has achieved remarkable effect in coal seam reconstruction, and application exploration in the field of coal safety mining has been carried out. However, the previous understanding of the basic CWS fracturing rules under the constraints of geological engineering factors is insufficient due to the limitation of experimental and field monitoring conditions, which restricts the exploration of the fracturing mechanism and the optimization of the field operation parameters. In view of this, based on the description of CSW coal seam reformation and its engineering scientific problems, the …


Study On Density Of The Supercritical Methane, Zhang Xinbin, Song Dangyu, Li Yunbo, Qi Yong'an, Fan Shunli Feb 2021

Study On Density Of The Supercritical Methane, Zhang Xinbin, Song Dangyu, Li Yunbo, Qi Yong'an, Fan Shunli

Coal Geology & Exploration

The density of supercritical methane is not only an important parameter for calculation of unconventional natural gas resources and adsorption capacity of methane in coal, but also a main indicator for measurement of the diffusion efficiency of supercritical methane and the ability to dissolve organic matter. Through analysis and comparison of the applicability of various gas state equations, it is realized that the Helmholtz energy state equation can accurately calculate the density of methane under the conditions of 0-30 MPa and 270-360 K. A calculation program for methane density was written using Microsoft Office Excel, and the error was less …


Effects Of Alternating Stress On Casing Damage Mechanism, An Fengchen, Zhang Feiyang, Yi Hao, Zhang Sui'an Feb 2021

Effects Of Alternating Stress On Casing Damage Mechanism, An Fengchen, Zhang Feiyang, Yi Hao, Zhang Sui'an

Coal Geology & Exploration

Horizontal well staged fracturing technology of horizontal well has been widely used in the exploitation of low-permeability oil and gas reservoirs and coalbed methane, and has achieved good economic results. However, the vertical section of the casing is found to be damaged with serious deformation in the process of multi-stage hydraulic fracturing, which will prevent bridge plugs from being installed at the preferred design depths, thereby resulting in abandonment of all remaining fracturing stages. In this study, a user element is developed to simulate the mechanical behavior at the casing-cement sheath interface under cyclic loads. The developed element is then …


Micro-Pore Structure And Fractal Characteristics Of Terrestrial Shales: A Case Study Of Shahezi Formation In Xujiaweizi Fault Depression, Lin Zizhi, Lu Shuangfang, Chang Xiangchun, Li Junqian, Zhang Pengfei, Zhou Nengwu, Zhang Yu, Wang Junjie, Huang Hongsheng Feb 2021

Micro-Pore Structure And Fractal Characteristics Of Terrestrial Shales: A Case Study Of Shahezi Formation In Xujiaweizi Fault Depression, Lin Zizhi, Lu Shuangfang, Chang Xiangchun, Li Junqian, Zhang Pengfei, Zhou Nengwu, Zhang Yu, Wang Junjie, Huang Hongsheng

Coal Geology & Exploration

The pore structure and fractal characteristics of shale are analyzed, and their impacting factors are also revealed using the low temperature nitrogen adsorption-desorption method, combined with scanning electron microscopy, C-S analysis and XRD. The results showed that the mineral compositions of Shahezi Formation continental shales were dominated by clay minerals, quartz and feldspar. The pore types in shales were mainly clay mineral intragranular pores, feldspar dissolution pores and grain edge pore, while the organic pores were not developed. The adsorption isotherms of shales belonged to the type Ⅳ isotherm according to the IUPAC, which develop two types of hysteresis loop, …