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Records Added in August 2023
Records added in August 2023
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Showing records 76 to 100 of 177. [First] Page: 1 2 3 4 5 6 7 8 Last
A Novel Inner Wall Coating-Insulated Oil Pipeline for Scale and Wax Prevention
Jing Cao, Wenhai Ma, Weiming Huang, Zhanfei Su, Yunbo Zhu, Jianjun Wang
August 3, 2023 (v1)
Subject: Materials
Keywords: coating material, numerical model, oil pipeline, thermal insulation performance
During the production of deep oil and gas, scaling, waxing, hydrate ice plugging and other problems easily occur. To solve these problems, reducing the temperature loss of oil pipelines is a feasible method. In order to protect the outer wall coating from being damaged and losing its thermal insulation performance, this paper proposes a developed technology for a novel inner wall coating-insulated oil pipeline. A new temperature-resistant and heat-insulating material aerogel was optimized and developed, and it has an extremely low thermal conductivity of less than 0.055 W/m·K. The influence of different coating processes on the thermal insulation coefficient was analyzed, and a novel inner wall coating-insulated oil pipeline was developed. A testing and evaluation platform for its thermal insulation effect was built, and a finite element model was established to analyze the temperature field distribution. When the thickness of the inner coating was 0.5 mm, the thermal insulation effect... [more]
Development of a Lux Meter for the Identification of Liquids in Post-Consumer Polyethylene Terephthalate Bottles for Collection Centers in Mexico
L. A. Ángeles-Hurtado, Juvenal Rodríguez-Reséndiz, Hilda Romero Zepeda, Hugo Torres-Salinas, José R. García-Martínez, Silvia Patricia Salas-Aguilar
August 3, 2023 (v1)
Keywords: ANOVA, automation, classification, illuminance, lux meter, Machine Learning, municipal solid waste, PET, recycling
This article aims to enhance technological advancements in the classification of polyethylene terephthalate (PET) bottle plastic, positively impacting sustainable development and providing effective solutions for collection centers (CC) in Mexico. Three experimental designs and machine learning tools for data processing were developed. The experiments considered three factors: bottle size, liquid volume, and bottle labels. The first experiment focused on determining the sensor distance from post-consumer PET bottles. The second experiment aimed to evaluate the sensor’s detection ability with varying liquid levels, while the third experiment assessed its detection capability for bottle labels. A digital lux meter integrated with a microcontroller was developed to monitor illuminance in post-consumer PET bottles containing liquid as they moved through a conveyor belt at an average rate of three bottles per second. The implemented methodology successfully detected liquids inside transpare... [more]
Finite Element Analysis and Prediction of Rock Mass Permeability Based on a Two-Dimensional Plane Discrete Fracture Model
Bochao Zhang, Lixin Wang, Jianming Liu
August 3, 2023 (v1)
Keywords: fracture parameters, groundwater, permeability, seepage, underground engineering
The safety of underground engineering projects is significantly influenced by groundwater. One of the key complexities is identifying the primary seepage paths within underground rock formations, understanding the patterns of seepage, and determining the effects of fracture parameters on the fluid movement inside the rock mass. To address these issues, a probabilistic model is constructed for random fractures using the finite element method, reflecting the random nature of fracture distributions in the real world. This model allows for an in-depth examination of the distribution of pore water pressure and Darcy velocity field, revealing the permeability trends in fractured rock masses. A variety of fracture models were devised to understand the relationship between factors such as fracture density, length, length power law, angle, dispersion coefficient, aperture, and power law, and how they affect the overall permeability of rock masses. The study suggests that, in the context of disc... [more]
Changes in Carcass Composition, Meat Quality Traits, and Stress Levels in Culled Sows Exposed to Different On-Farm Rest Periods
Kristina Gvozdanović, Ivona Djurkin Kušec, Mislav Đidara, Senka Blažetić, Miodrag Komlenić, Krešimir Kuterovac, Žarko Radišić, Goran Kušec
August 3, 2023 (v1)
Keywords: carcass composition, cortisol levels, culled, pig meat quality, resting period, sow
The study investigated the effect of on-farm rest period (RP) on carcass composition, meat quality, and stress indicators of culled sows. The study was conducted on 84 Large White × Landrace culled sows, which were divided into seven groups (n = 12) with respect to the duration of the on-farm rest period: no rest period (N-RP) group and 1 to 6 weeks of on-farm rest period (1−6 RP). After completion of the on-farm RP, each group of culled sows was slaughtered and the carcass and meat quality traits were determined. Sows from 6-RP had a significantly higher dressing percentage and backfat thickness and, together with sows from 5-RP, a higher shoulder weight. The highest shoulder percentage was found in the 3-RP and 4-RP groups, while 1-RP had the highest percentage for the belly−rib part. At the same time, RP influenced the final pH values (pH24 SM and pH24 LL) measured in the longissimus thoracis et lumborum (LT) and in the musculus semimembranosus (SM), as well as drip loss, thawing lo... [more]
Low-Carbon and Energy-Saving Path Optimization Scheduling of Material Distribution in Machining Shop Based on Business Compass Model
Yongmao Xiao, Hao Zhang, Ruping Wang
August 3, 2023 (v1)
Keywords: business compass, dung beetle optimizer, low carbon, material distribution, path planning
In order to reduce carbon emission and energy consumption in the process of raw material distribution, the workshop material distribution management model was established based on the business compass model; it can help guide enterprises to manage workshop production. Based on the raw material distribution equipment, a path calculation model considering the carbon emission and energy consumption in the process of raw material distribution was established. The dung beetle optimizer was selected for the optimization calculation. The dung beetle optimizer has the characteristics of fast convergence and high solution accuracy. The material distribution of an engine assembly workshop was taken as an example; the results showed that the optimized scheduling model could effectively optimize the material distribution route and reduce energy consumption and carbon emission in the distribution process on the basis of meeting the distribution demand.
Research on Hydraulic Thruster-Enhanced Permeability Technology of Soft Coal Drilling through Strata Based on Packer Sealing Method
Zhuangzhuang Yao, Zhigang Zhang, Linchao Dai
August 3, 2023 (v1)
Keywords: “Three Soft” coal seam, anti-reflection effect, cross-bed drilling, hydraulic fracturing, hydraulic punching, straddle double packer
According to the characteristics of “Three Soft” outburst coal seams in the Henan area with large gas content, poor air permeability, and extremely difficult extraction, the hydraulic fracturing and punching technology of soft coal with packer tool string sealing method was studied. Xinzheng Coal Electric Power Company is a coal and gas outburst mine, and the second coal seam is a typical soft outburst coal seam. In 14201, upper bottom drainage roadway, which has a broken top plate, a test of penetration hydraulic pressure thrust-enhanced permeability technology based on packer sealing mode was carried out. The average concentration in the press-punching area was 4.8 times that in the non-press-punching area (to be tested), and the average pure volume of 100 holes in the test area was 42 times that in the untested area. During hydraulic pressure punching in the test area, affected by fracturing disturbance, the concentration and purity of the test area and the adjacent test area signif... [more]
Fracture Propagation Mechanism of Tight Conglomerate Reservoirs in Mahu Sag
Yue Zhu, Yusen Deng, Jianhua Qin, Jing Zhang, Yushi Zou, Shicheng Zhang, Shikang Liu
August 3, 2023 (v1)
Keywords: fracture propagation, Mahu Sag, pressure curve, tight conglomerate, true tri-axial hydraulic fracturing
Conglomerate reservoirs are usually formed in sag slope belts, which have the characteristics of near-source rapid deposition, rapid sedimentary facies change, and distinct reservoir heterogeneity. Therefore, it is difficult to carry out treatments of stimulation because of insufficient understanding of the propagation mechanism of the unique “gravel-bypassing” and “gravel-penetrating” characteristics of fracture morphologies in Mahu conglomerate reservoirs. In order to study the law of hydraulic fracture propagation in conglomerate reservoirs, based on Brazilian splitting test results for conglomerates with different gravel particle sizes and different cementation degrees, true tri-axial fracturing experiments conducted in the laboratory were performed to conduct experimental research on natural conglomerate outcrops and analyze the effects of gravel size, fracturing fluid viscosity, and pumping rate on hydraulic fracture propagation morphology. The results show that: (1) the gravel c... [more]
Research on a Photovoltaic Power Prediction Model Based on an IAO-LSTM Optimization Algorithm
Liqun Liu, Yang Li
August 3, 2023 (v1)
Keywords: Aquila optimization algorithm, neural networks, PV power prediction
With the rapid popularization and development of renewable energy, solar photovoltaic power generation systems have become an important energy choice. Convolutional neural network (CNN) models have been widely used in photovoltaic power forecasting, with research focused on problems such as long training times, forecasting accuracy and insufficient speed, etc. Using the advantages of swarm intelligence algorithms such as global optimization, strong adaptability and fast convergence, the improved Aquila optimization algorithm (AO) is used to optimize the structure of neural networks, and the optimal solution is chosen as the structure of neural networks used for subsequent prediction. However, its performance in processing sequence data with time characteristics is not good, so this paper introduces a Long Short-Term Memory (LSTM) neural network which has obvious advantages in time-series analysis. The Cauchy variational strategy is used to improve the model, and then the improved Aquil... [more]
Integrating TPM and Industry 4.0 to Increase the Availability of Industrial Assets: A Case Study on a Conveyor Belt
David Mendes, Pedro D. Gaspar, Fernando Charrua-Santos, Helena Navas
August 3, 2023 (v1)
Keywords: case study, conveyor belt, Industry 4.0 (I4.0), Internet of Things (IoT), lean philosophy, maintenance, maintenance management, process optimization, real-time monitoring, total productive maintenance (TPM)
As the global market becomes increasingly competitive and demanding, companies face the challenge of responding swiftly and efficiently to customer needs. To maintain a competitive advantage, organisations must optimise the usage of their assets. This study focuses on the critical role of maintenance management and presents a novel, cost-effective, and easily applicable model that integrates Industry 4.0 (I4.0) and Total Productive Maintenance (TPM) principles to enhance production processes. The proposed model incorporates a real-time monitoring system equipped with sensors, a gateway, and Internet of Things (IoT) services. These components enable data acquisition, transmission, storage, and visualisation through both mobile and fixed devices. The model’s effectiveness was validated through its implementation on a conveyor belt in a feed mill. The availability of the conveyor belt was around 89.5% before TPM implementation. After the implementation of TPM, it was possible to observe t... [more]
Drug Formulation of Securigera securidaca Seed Extracts
Mohamed E. M. Abdelbagi, Ghassab M. Al-Mazaideh, Adil Elhag Ahmed, Fuad Al-Rimawi, Haya Ayyal Salman, Abdulrahman Almutairi, Faraj Ahmad Abuilaiwi, Fadel Wedian
August 3, 2023 (v1)
Subject: Biosystems
Keywords: diosgenin, drug formulation, S. securidaca, trigonelline
seeds are reported to treat a variety of diseases; they contain multiple antidiabetic constituents and are widely used as anti-hyperglycemic, antibacterial, as well as anti-hyperlipidemic agents. The present work aimed to propose tablet formulations containing extracts of S. securidaca seeds in an attempt to obtain antibacterial and anti-hyperglycemic formulations with a more efficient oral hypoglycemic impact, limited side effects, and higher patient compliance for the first time, resulting in multiple benefits. Tablet formulations were created by encapsulating granules from S. securidaca seed extracts with varying concentrations of sodium starch glycolate as a super-disintegrant (0−3%). The final formulations were examined for weight variation, solubility, hardness, water content, disintegration time, friability, drug content (trigonelline and diosgenin), and in vitro drug release. The S. securidaca tablet formulations completed the weight test because the percentage deviation in the... [more]
Optimization of Supercritical Carbon Dioxide Fluid Extraction of Medicinal Cannabis from Quebec
Hinane Boumghar, Mathieu Sarrazin, Xavier Banquy, Daria C. Boffito, Gregory S. Patience, Yacine Boumghar
August 3, 2023 (v1)
Subject: Optimization
Keywords: Box–Behnken, cannabinoids, Optimization, supercritical carbon dioxide
Research on cannabis oil has evolved to encompass the pharmaceutical industry for the therapeutic potential of the active compounds for pathologies such as Alzheimer, auto-immune disorders, and cancer. These debilitating diseases are best treated with cannabinoids such as tetrahydrocannabinol (∆9-THC), cannabigerol (CBG), and cannabinol (CBN), which relieve neuropathic pain and stimulate the immune system. We extracted cannabinoids from plants with supercritical CO2 and produced an extract with a total yield close to 26%. The three-level Box−Behnken experimental design considered four factors: Temperature, pressure, CO2 flow rate, and processing time, with predetermined parameters at low, medium, and high levels. The mathematical model was evaluated by regression analysis. The yield of ∆9-THC and CBG reached a maximum after 2 h and 15 g/min of CO2, 235 bar, 55 °C (64.3 g THC/100 g of raw material and 4.6 g CBG/100 g of raw material). After another 2 h of extraction time, the yield of C... [more]
Laboratory Test of Fluid Physical Property Parameters of Well Fluid Containing CO2
Minghua Zou, Jifei Yu, Huan Chen, Menglong Li, Guang‘ai Wu, Haowen Shi, Hanqing Bian, Xiaobo Liao, Lijuan Huang
August 3, 2023 (v1)
Keywords: CO2–oil system, density, laboratory test, solution, viscosity, volume factor
Change regulation of the physical properties of fluid is key to accurately predicting multiphase fluid flow in the production wellbore of CO2 flooding reservoirs. Given the characteristics of significant changes in pressure, temperature, and CO2 content in the whole wellbore of production wells in CO2 flooding reservoirs, this paper systematically studied the change rules of volume factor, viscosity, density, and solubility of well fluid for pressure 5~30 MPa, temperature 20~120 °C, and CO2 content 10~90% through single degassing PVT experiments. According to the experimental results, the volume factor of crude oil increases first and then decreases with the pressure increase. At the bubble point pressure (20 MPa), the volume factor of crude oil can reach 1.89 at high temperatures. The volume factor can be increased from 1.28 to 1.44 at 8 MPa when the temperature increases from 20 °C to 120 °C. Under the bubble point pressure, the increase in pressure increases the solubility of CO2, a... [more]
Biodiesel Production from Waste Cooking Oil: A Perspective on Catalytic Processes
Montserrat Cerón Ferrusca, Rubi Romero, Sandra Luz Martínez, Armando Ramírez-Serrano, Reyna Natividad
August 3, 2023 (v1)
Keywords: bifunctional catalysts, biodiesel, transesterification, waste cooking oil
Presently, the use of fossil fuels is not ecologically sustainable, which results in the need for new alternative energies such as biodiesel. This work presents a review of the classification of the lipidic feedstocks and the catalysts for biodiesel production. It also presents the pros and cons of the different processes and feedstocks through which biodiesel is obtained. In this context, cooking oil (WCO) has emerged as an alternative with a high potential for making the process sustainable. A detected limitation to achieving this is the high content of free fatty acids (FFA) and existing problems related to homogeneous and heterogeneous catalysts. To overcome this, the use of bifunctional catalysts is being evaluated by the scientific community. Thus, this work also explores the advances in the study of bifunctional catalysts, which are capable of simultaneously carrying out the esterification of free fatty acids (FFA) and the triglycerides present in the WCO. For the sake of an imp... [more]
Propagation Law of Hydraulic Fracture across the Coal−Rock Interface under the Co-Effect of Natural Fractures and Tectonic Stress
Dijie Zhu, Wenda Li, Dong Niu, Hecheng Xiao, Xiaoxia Song
August 3, 2023 (v1)
Keywords: horizontal well position, indirect fracturing, natural fracture, pore pressure cohesive element, tectonic stress
Indirect fracturing from roof rock to coal using a horizontal well is a new and promising technology for coalbed methane surface exploitation in soft and low-permeability coal seams. In order to study the propagation law of hydraulic fractures across the coal−rock interface, a pore pressure cohesive element is used to establish a numerical model for indirect fracturing. Combined with practical engineering in a 3# coal seam in the Xinjing mine in China, the propagation behavior of hydraulic fractures across the coal−rock interface was researched, and the range of the horizontal well position for indirect fracturing was determined. The results show that: (1) the pore pressure cohesive element can be used to accurately simulate the interaction between hydraulic fractures and natural fractures, and the propagation of hydraulic fractures across the coal−rock interface. (2) As the vertical distance between the horizontal well and coal−rock interface decreases, the breakdown pressure of perfo... [more]
Food Production Scheduling: A Thorough Comparative Study between Optimization and Rule-Based Approaches
Maria E. Samouilidou, Georgios P. Georgiadis, Michael C. Georgiadis
August 3, 2023 (v1)
Keywords: food process industry, heuristics, MILP, Optimization, production scheduling
This work addresses the lot-sizing and production scheduling problem of multi-stage multi-product food industrial facilities. More specifically, the production scheduling problem of the semi-continuous yogurt production process, for two large-scale Greek dairy industries, is considered. Production scheduling decisions are made using two approaches: (i) an optimization approach and (ii) a rule-based approach, which are followed by a comparative study. An MILP model is applied for the optimization of short-term production scheduling of the two industries. Then, the same problems are solved using the commercial scheduling tool ScheduleProTM, which derives scheduling decisions using simulation-based techniques and empirical rules. It is concluded that both methods, despite having their advantages and disadvantages, are suitable for addressing complex food industrial scheduling problems. The optimization-based approach leads to better results in terms of operating cost reduction. On the oth... [more]
Supercritical CO2 Extraction of Seed Oil from Psophocarpus tetragonolobus (L.) DC.: Optimization of Operating Conditions through Response Surface Methodology and Probabilistic Neural Network
Padej Pao-la-or, Boonruang Marungsri, Kakanang Posridee, Ratchadaporn Oonsivilai, Anant Oonsivilai
August 3, 2023 (v1)
Keywords: oleic acid, probabilistic neural network, Psophocarpus tetragonolobus (L.) DC., response surface methodology, supercritical fluid extraction
For the treatment of menopausal symptoms, nutraceuticals and herbal remedies are thought to be more natural and safer than hormones. Attention has been paid to the winged bean (Psophocarpus tetragonolobus (L.)) DC. seed oil. They are constituted of phytosterols, which may be effective in preventing menopausal symptoms. The purpose was to determine the optimal conditions for supercritical fluid extraction of oleic-rich oil from winged bean seeds. To optimize the condition, the response surface methodology (RSM) and probabilistic neural network (PNN) were utilized. In this research, PNN was used to improve RSM estimation by reducing the number of calculations. The optimized extraction conditions for winged bean seed oil entailed a CO2 flow rate of 21.3 L/h, a pressure of 30 MPa, a temperature of 55 °C, and an extraction time of 90 min. Under these conditions, the extraction process yielded a maximum oil yield of 36.27%. Ultimately, winged bean seed oil included a greater proportion of un... [more]
Cross-Linking of White Proteins in Soft-Shell Turtle Eggs Using Transglutaminase, Reductant, and Thermal Pretreatment
Chun-Chi Chen, Ming-Ching Kao, Meng-I Kuo, Chao-Jung Chen, Cheng-Hsun Jao, Yongcheol Lee, Jung-Feng Hsieh
August 3, 2023 (v1)
Subject: Biosystems
Keywords: cross-linking, egg protein, reducing agent, soft-shell turtle, transglutaminase
The effects of transglutaminase (TGase), reductant, and thermal treatment on the cross-linking of white proteins in soft-shell turtle eggs were investigated. Egg white proteins were denatured by reductant (0.83% 2-mercaptoethanol, 2-ME) pretreatment and thermal pretreatment (95 °C and 5 min), and the denatured proteins were then catalyzed by TGase (1.0 unit/mL). SDS−PAGE showed that without any pretreatments, three major egg white proteins (210 kDa, 115 kDa, and 76 kDa proteins) were inferior substrates for TGase. Only portions of the 210 kDa protein (7.9%), 115 kDa protein (11.4%), and 76 kDa protein (42.9%) were polymerized by TGase into high-molecular-weight (MW) protein polymers (>180 kDa) after incubation for 3 h at 40 °C. However, the combined use of TGase with 0.83% 2-ME and thermal pretreatment led to a significant increase (p < 0.05) in the rate of white protein polymerization after 3 h: 210 kDa protein (90.8%), 115 kDa protein (69.5%), and 76 kDa protein (72.2%). Particle... [more]
Sensitivity Analysis of Oil and Gas Production in the In Situ Pyrolysis of Oil Shale
Yiwei Wang, Jun Luo, Zhenghong Shang
August 3, 2023 (v1)
Keywords: in situ pyrolysis, numerical simulation, oil shale, sensitivity analysis
The Maoming basin in south China is rich in oil shale resources, whereas the Youganwo formation is a potential area for large-scale in situ exploration because of its relatively large thickness, high oil content, and good continuity. Based on previous geologic studies on the Maoming basin and the laboratory experimental data, in situ pyrolysis models for shale oil are established using the CMG-STARS software to simulate the in situ heating and reactions. To analyze the major influencing factors, the CMOST module is employed to conduct the sensitivity analysis with accumulated oil and gas production as the target functions. The initial kerogen concentration, formation permeability, activation energy of pyrolysis reaction, frequency factor, heating rate, heating power, heat loss, heat conductivity, heat capacity, and bottom-hole pressure are chosen to be the controlling parameters. A total of 128 cases are calculated for each target function with the fractional factorial sampling method.... [more]
Minimising Leachate Wastewater Generated from NaOH-Catalysed Biodiesel Synthesis from Methanol
Mario Alberto Pérez-Méndez, Guadalupe Selene Fraga-Cruz, Gladys Jiménez-García, Rafael Maya-Yescas, Fabricio Nápoles-Rivera
August 3, 2023 (v1)
Keywords: biodiesel, minimization of leaching water, minimization of sodium hydroxide, operating conditions, transesterification homogeneous basic route
Currently, energy generation based on fossil fuels is producing negative environmental impacts; two of the main symptoms of these impacts are water pollution and climate change. Consequently, the search for new technologies to satisfy the energy demand must have the goal to minimise possible impacts to the environment. There are alternatives with biofuels and, among them, biodiesel. The cheapest reaction pathway for biodiesel production is the transesterification of triglycerides by methanol in the presence of sodium hydroxide; however, this option can contaminate large volumes of water used in the final leach of the biodiesel product. Therefore, a feasible way of producing this biofuel while simultaneously minimising leaching water will be environmentally friendly and will improve economical savings. The present study developed an experimental design in order to minimise the addition of NaOH during biodiesel production by the basic homogeneous pathway. The best operating conditions we... [more]
Fault Location of Distribution Network Based on Back Propagation Neural Network Optimization Algorithm
Chuan Zhou, Suying Gui, Yan Liu, Junpeng Ma, Hao Wang
August 3, 2023 (v1)
Keywords: BPNN, cloud genetic algorithm, fault diagnosis, Optimization
Research on fault diagnosis and positioning of the distribution network (DN) has always been an important research direction related to power supply safety performance. The back propagation neural network (BPNN) is a commonly used intelligent algorithm for fault location research in the DN. To improve the accuracy of dual fault diagnosis in the DN, this study optimizes BPNN by combining the genetic algorithm (GA) and cloud theory. The two types of BPNN before and after optimization are used for single fault and dual fault diagnosis of the DN, respectively. The experimental results show that the optimized BPNN has certain effectiveness and stability. The optimized BPNN requires 25.65 ms of runtime and 365 simulation steps. And in diagnosis and positioning of dual faults, the optimized BPNN exhibits a higher fault diagnosis rate, with an accuracy of 89%. In comparison to ROC curves, the optimized BPNN has a larger area under the curve and its curve is smoother. The results confirm that t... [more]
Advances in Deep Eutectic Solvents: New Green Solvents
Shuhang Ren, Tiancheng Mu, Weize Wu
August 3, 2023 (v1)
Subject: Materials
This Special Issue, entitled “Advances in deep eutectic solvents: New green solvents”, was organized to collect original research articles on the latest developments in the new green solvents, deep eutectic solvents (DESs), and their applications [...]
Study on Casing Safety Evaluation in High-Temperature Wells with Annular Pressure Buildup
Hao Wang, Mu Li, Qing Zhao, Weiwei Hao, Hui Zhang, Yafei Li, Pengpeng Huang, Yi Zou
August 3, 2023 (v1)
Subject: Other
Keywords: annular pressure buildup, casing safety, high-temperature well, offshore thermal recovery well, pressure management
In high-temperature wells, annular pressure buildup (APB) caused by temperature increase is a widespread phenomenon in production, especially in offshore thermal recovery wells. It increases the load on the tubing and casing and consequently threatens the wellbore integrity. Hence, research on casing safety evaluation and APB management has great significance for field production. In this paper, the tubing and casing safety evaluation and APB limit determination methods are presented considering the effect of thermal stress and APB. Based on the case study of an offshore thermal recovery well, an APB-management chart and the recommended optimal range of APB are provided. Finally, an analysis of three commonly used mitigation methods is presented. The effect and the recommended parameters of these mitigation methods are further discussed. The research results show that the thermal stress and APB phenomena affect the stress distribution of the casing and may bring great danger to the wel... [more]
Special Issue “Methane Reforming Processes”
Andrea Di Giuliano, Katia Gallucci
August 3, 2023 (v1)
This Special Issue, entitled “Methane Reforming Processes”, of the MDPI journal Processes, embraces wide-ranging aspects of interest in the exploitation of methane reforming reactions and related chemical species, from a point of view that aligns with the scope of this open access journal [...]
Nonlinear Analysis of Cross Rolls of Electrically Conducting Fluid under an Applied Magnetic Field with Rotation
Y. Rameshwar, G. Srinivas, A. Krishna Rao, U. S. Mahabaleshwar, D. Laroze
August 2, 2023 (v1)
Subject: Other
Keywords: cross rolls, earth’s liquid core, electrically conducting fluid, nonlinear convection, planar layer dynamos
The proposed planer layer dynamo physical model has real-world applications, especially in the Earth’s liquid core. Thus, in this paper, an attempt is made to understand the finite amplitude convection when there exists a coupling between the Lorentz force and the Coriolis force. In particular, the effect of a horizontally applied magnetic field is studied on the Rayleigh−Bénard convection (RBC) that contains the electrically conducting fluid and rotates about its vertical axis. Free−free boundary conditions are assumed on the geometry. Attention is focused on the nonlinear convective flow behavior during the occurrence of cross rolls which are perpendicular to the applied magnetic field and parallel to the rotation axis. The visualization of cross rolls is achieved using the Fourier analysis of perturbations up to the O(ε8). The relationship of the Nusselt number (Nu) with respect to the Rayleigh number (R), the Ekman number (E), and the Elsasser number (Λ) is investigated. It is obse... [more]
Quantitative Characteristics of Micro Bedding Fractures in the Wufeng−Longmaxi Formation Based on High-Resolution Map Imaging Technology
Conghui Zhao, Dong Wu, Fengbo Hu, Meng Sun, Tao Li, Hu Wang
August 2, 2023 (v1)
Subject: Materials
Keywords: aperture, fracture length, line density of fracture, shale, Sichuan basin
The study of microfractures in shale is mainly based on qualitative description. Conversely, quantitative description of the parameters of shale microfractures can provide a quantitative basis for shale fracture characterization and shale physical properties. Nine shale reservoir samples of the Wufeng−Longmaxi Formation in the Jiaoshiba area were studied, using the backscattered two-dimensional multiscale resolution imaging technology, combined with high-resolution map imaging technology (MAPS), and thousands of images were obtained using scanning electron microscopy. Gray image analysis was used to extract microfracture information from images (2 × 2 cm multiresolution). The “maximum circle method” was used to calculate the length and aperture characteristics of the fractures. Parameters such as the area of the bedding fractures, the surface rate of the fractures, and the linear density of the fractures were obtained by the integration of apertures. The fracture length was between 2~7... [more]
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