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Records Added in April 2023
Records added in April 2023
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Showing records 151 to 175 of 9292. [First] Page: 3 4 5 6 7 8 9 10 11 Last
Assessing the Impact of Ethanol/Biodiesel/Diesel Blends and Nanoparticle Fuel Additives on Performance and Emissions in a DI Diesel Engine with EGR Integration: An Experimental Study
Raouf Mobasheri, Abdel Aitouche, Sadegh Pourtaghi Yousefdeh, Abbas Zarenezhad Ashkezari
April 28, 2023 (v1)
Keywords: biodiesel, EGR, emission, Ethanol, TiO2 nano additive
In this paper, the effect of nano-particles along with EGR rates was experimentally assessed on the performance and emission of a DI diesel engine fueled by biodiesel and ethanol. For this purpose, three levels of TiO2 nanoparticles (0, 40, and 60 ppm) were added to biodiesel/diesel blends in the proportions of 0, 10, and 20% biodiesel with ethanol at levels of 0, 4, and 6%. EGR rates were used at 0, 20, and 30%. A total of 31 fuel samples with different ethanol, biodiesel, TiO2 nano-additives, and EGR rates were tested at different speeds. The equation for this combination is BxEy + EGRw + TiO2z, where x, y, w, and z are the percentages of biodiesel, ethanol, EGR, and TiO2. The results showed that the mixture of B10E4 + EGR20 + TiO260, reduced the amount of NOx, CO, and HC by 10, 12.4, and 17%. Moreover, due to the significant reduction of emissions and performance improvement, the combinatory method of EGR−TiO2 nano-additives can be used as an effective formula for diesel engines fue... [more]
Advancing Manganese Content Prediction in Submerged Arc Welded Metal: Development of a Multi-Zone Model via the Calphad Technique
Jin Zhang, Ping Liu, Dan Zhang
April 28, 2023 (v1)
Keywords: chemical reactions, compositional control, equilibrium principles, gas–slag–metal equilibrium, submerged arc welding, welding process
Manganese is a vital element in determining the mechanical properties of submerged arc welded metal. To ensure a reliable weld, the equilibrium model has been used for decades to predict and control the manganese content, particularly when MnO-bearing fluxes are applied. However, the equilibrium model only considers chemical interactions within the weld pool zone, leading to significant inaccuracies. To address this limitation, we propose a multi-zone model that accounts for all of the essential reaction zones in the submerged arc process via the Calphad technique. The model’s accuracy is verified by predicting the manganese content, the flux oxygen potential, and the neutral point location for the typical MnO-bearing fluxes covering acidic, neutral, and basic fluxes. The results indicate that the multi-zone model offers superior accuracy compared to the equilibrium model, which neglects significant oxygen improvement and alloy evaporation in the droplet zone. Further analysis of therm... [more]
Optimization of Fire Brigade Deployment by Means of Mathematical Programming
Bohuš Leitner, Michal Ballay, Marek Kvet, Michal Kvet
April 28, 2023 (v1)
Keywords: fire brigade deployment, location analysis, mathematical modeling, service accessibility improvement
The content of this research paper is focused on the applications of selected operation research methods in the field of rescue services. The first theoretical part aims at identifying the most important aspects of the real system, which should be taken into account whenever a rescue system is to be redesigned or optimized. It also contains an in-depth description of system performance. Based on the found criteria, a mathematical model for a new system design is proposed. The second part of this paper is practically oriented. A short case study performed with real data on the rescue service system in Slovakia is reported herein, and the obtained results are compared with current fire brigade deployment. We concentrate on improving the most important criteria of the real system. If the suggested mathematical model proves to be hard to solve with common optimization tools, we will develop an efficient solving algorithm. From a general point of view, the main scientific goal of this resea... [more]
Comparative Analysis of the Engine Performance and Emissions Characteristics Powered by Various Ethanol−Butanol−Gasoline Blends
Ashraf Elfasakhany
April 28, 2023 (v1)
Keywords: blends, Butanol, comparative, dual, Ethanol, ternary
Although many biofuel blends have been proposed recently, comparisons of such blends are rarely investigated. Currently, it is extremely difficult to recommend one biofuel blend over another since comparisons are not carried out under the same engine conditions. In the current study, different biofuel blends in dual and ternary issues are compared together, as well as with conventional gasoline under the same engine conditions. Five different biofuel blends are considered, i-butanol (iB), n-butanol (nB), bio-ethanol (E), n-butanol−bio-ethanol (nBE), and i-butanol−bio-ethanol−gasoline (iBE) blends, at two different engine speeds (2500 and 3500 rpm/min). Additionally, the blends are compared in the average bases through wide engine speeds. The comparisons of blends are carried out via engine performance and emissions. The performance includes engine power, torque, and volumetric efficiency, while the emissions include CO, CO2, and UHC. Results showed that the E blends presented higher pe... [more]
A Review on Observer Assistance Systems for Harvested and Protected Fish Species
Taehoon Koh, Yonghoon Kim
April 28, 2023 (v1)
Keywords: crowdsourcing, harvest, object detecting, protected fish species, YOLO
Restrictions on competitive fishing activities due to the depletion of living marine resources and the monitoring of fish resources for the purpose of marine ecosystem research are supported by statistics on the protection of fish resources and ecosystem research, which are gathered through existing observer monitoring systems. However, in the case of deep-sea fishing vessels and special-purpose fishing vessels, some matters, such as collusive transactions with shipping companies and shipowners and threats toward the observer, are problematic, as observers are always active on board. Therefore, through the present study we would like to discuss the methodology and directions for research on the independent role of the observer and the methods for improving the reliability of data through systems that automate the monitoring of the acquisition of fish resources, which is expected to be a continuing problem. After an analysis of research trends for each issue related to the electronic mo... [more]
Electrochemical Surface Treatment for Tailored Porous Structures
Hamid Reza Godini, Anirudh Venkat Prahlad, Vesna Middelkoop, Oliver Görke, Sirui Li, Fausto Gallucci
April 28, 2023 (v1)
Keywords: catalyst support, metal membrane, Plasma Electrolytic Oxidation, tailoring
Plasma electrolytic oxidation (PEO) was used to establish a porous metal oxide layer on various titanium and zirconium workpieces in the form of wires, porous tubes, and 3D-printed structures. The ultimate goal of the work was to create a layer with the desired characteristics over a catalyst support or metal membrane structures to improve the performance of the targeted high-temperature catalytic conversion or separation applications. In doing so, it was ensured that the PEO-treated layer could provide the desired morphology, thickness, and porosity needed for the final processing step, which is usually a conventional coating method. This addresses the limitations of ceramic structures, including their mechanical resistance, thermal resistance, and conductivity, and their potential for being functionalized and utilized for high-temperature applications. The entire experimental run was carried out using a 2 kilowatt (maximum output) AC-power source with a maximum current limit of 6.5 A... [more]
Predictive Control Strategy for Continuous Production Systems: A Comparative Study with Classical Control Approaches Using Simulation-Based Analysis
Amelia Chindrus, Dana Copot, Constantin-Florin Caruntu
April 28, 2023 (v1)
Keywords: continuous manufacturing, cyber-physical system, linear quadratic regulator, Model Predictive Control, proportional-integral-derivative controller
Due to today’s technological development and information progress, an increasing number of physical systems have become interconnected and linked together through communication networks, thus resulting in Cyber-Physical Systems (CPSs). Continuous manufacturing, which involves the manufacture of products without interruption, has become increasingly important in many industries, including the pharmaceutical and chemical industries. CPSs can be used to control and monitor the production process, which is essential in enabling continuous manufacturing. This paper is focused on the modeling and control of physical systems required in tablet production using dry granulation. Tablets are a type of oral dosage form that is commonly used in the pharmaceutical industry. They are solid, compressed forms of medication that are formulated to release the active ingredients in a manner that allows for optimal absorption and efficacy. Thus, a model predictive control (MPC) strategy is applied to a pl... [more]
Multi-Factor Coupling Analysis of Porous Leakage in Underwater Gas Pipelines
Hong Ji, Jie Guo, Gao Zhang, Ke Yang, Juncheng Jiang, Yaxin Wang, Zhixiang Xing, Haipu Bi
April 28, 2023 (v1)
Keywords: multi-factor coupling analysis, numerical simulation, physical model experiment, porous leakage, similar principles, underwater gas pipeline
Natural gas pipeline leaks under the sea will have a significant negative effect on the marine ecosystem, result in significant financial losses, and possibly even harm marine floating objects. The VOF (Volume of Fluid) multi-phase flow model is used to numerically simulate and study the diffusion process of porous leakage in submarine gas pipelines. Experiments confirmed the model’s correctness and dependability. Based on this, the coupling effect and the porous effect of the leakage velocity, the size of the leaked pore, and water velocity of the natural gas pipelines on the diffusion of porous leakage in the submarine gas pipelines are analyzed with the test scheme designed by the orthogonal test method. The similarity principle is used to connect the leakage model with the actual application. The results show that three factors, namely, the leakage velocity, the size of leaked pore, and the water velocity, influence the shape of the air mass, the time when the gas reaches the sea s... [more]
An Energy-Efficiency Prediction Method in Crude Distillation Process Based on Long Short-Term Memory Network
Yu Zhang, Zhe Cui, Mingzhang Wang, Bin Liu, Xiaomin Fan, Wende Tian
April 28, 2023 (v1)
Keywords: crude distillation process, energy consumption prediction, Energy Efficiency, long short-term memory
The petrochemical industry is a pillar industry for the development of the national economy affecting people’s daily living standards. Crude distillation process is the core and leading unit of the petrochemical industry. Its energy consumption accounts for more than 20% of the total energy consumption of the whole plant, which is the highest energy consumption link. A model based on the long short-term memory network (LSTM) is proposed in this paper to predict and analyze energy efficiency. This model extracts the complex relationship between many process variables and predicts the energy efficiency of the crude distillation process. Firstly, the process simulation of crude distillation is carried out. By adding random disturbance, the data set in different working conditions is obtained, and the difference between the working conditions is expressed with the distance-coded heat map. Secondly, the Savitzky−Golay (SG) filter is used to smooth the data, which preserves the original char... [more]
Separation of Critical Metals by Membrane Technology under a Circular Economy Framework: A Review of the State-of-the-Art
Amilton Barbosa Botelho Junior, Jorge Alberto Soares Tenório, Denise Crocce Romano Espinosa
April 28, 2023 (v1)
Subject: Environment
Keywords: electrodialysis, membrane separation, nanofiltration, polymer inclusion, supported liquid
The demand for critical metals for net-zero technologies, including electric vehicles and wind/solar energy, puts pressure on extraction and recycling processes. As the treatment of solutions is becoming more and more complex and associated with the decreasing concentration of critical metals and the concentration of contaminants increasing, the development of separation techniques is required. Among them, membrane separation has been evaluated for hydrometallurgical processes with similar results to traditional techniques. This work aimed at reviewing the literature on membrane applications to obtain critical metals—lithium (Li), cobalt (Co), and rare earth elements (scandium—Sc, yttrium—Y, lanthanum—La, and neodymium—Nd). The main novelty is that this literature review focuses on the application of membrane techniques in industrial processes, not only water and wastewater treatment. For this, we searched a scientific database for different keywords, and the bibliometric analysis demo... [more]
GraphSAGE-Based Multi-Path Reliable Routing Algorithm for Wireless Mesh Networks
Pan Lu, Chuanfang Jing, Xiaorong Zhu
April 28, 2023 (v1)
Subject: Environment
Keywords: breadth-first search, GraphSAGE, multi-path reliable routing, network performance, wireless mesh networks
Wireless mesh networks (WMN) promise to be an effective way to solve the “last mile” access problem on the Internet of Things (IoT) and the key to next-generation wireless networks. The current routing algorithms of WMN are difficult to adapt to complex environments and guarantee the reliable transmission of services. Therefore, this paper proposes a reliable routing algorithm that combines the improved breadth-first search and a graph neural network, namely GraphSAGE. The algorithm consists of two parts: (1) A multi-path routing algorithm based on the improved breadth-first search. This algorithm can continuously iterate link information based on network topology and output all shortest paths. (2) A GraphSAGE-based performance optimization algorithm. This algorithm creates a method to generate network labels for supervised training of GraphSAGE. Then, the network labels and GraphSAGE are used to learn graph features to obtain the value of network performance for each shortest path. Fi... [more]
Analyzing SPIF Product Characteristics Using Full Factorial Design-Integrated PCA Approach
Adham E. Ragab
April 28, 2023 (v1)
Keywords: forming force, PCA, principal strain, profile accuracy, SPIF
The process of single-point incremental forming (SPIF) is a relatively new technology that is primarily used in the production of prototypes and small quantities of products. However, the process has several limitations with respect to the quality characteristics of its products. This study examined the effects of four process parameters—namely, tool diameter, feed rate, step size, and sheet thickness—on the characteristics of the final product. A total of 15 product responses were measured and/or calculated during the experiments. The responses fell under three different categories; surface profile accuracy, strain/stress/thinning, and forming forces. In previous published work, responses were studied separately for each category. The aim of this paper was to determine the relationships between responses using a principal component analysis (PCA). PCA is a well-known multivariate analysis technique used to reduce the dimensionality of data. As a result of the PCA, the product’s charac... [more]
Bibliometric Analysis of Constructed Wetlands with Ornamental Flowering Plants: The Importance of Green Technology
José Luis Marín-Muñiz, Irma Zitácuaro-Contreras, Gonzalo Ortega-Pineda, Luis Manuel Álvarez-Hernández, Karina Elizabeth Martínez-Aguilar, Aarón López-Roldán, Sergio Zamora
April 28, 2023 (v1)
Subject: Environment
Keywords: bibliometric study, ornamental plants, treatment wetlands, Wastewater
The use of constructed wetlands (CWs) for wastewater treatment has earned high interest around the world. However, innovations to improve its removal efficiency and adoption have been suggested in the last decades. For instance, the use of ornamental flowering plants (OFP), which make wetland treatment systems more aesthetic and is an option for the production of commercial flowers while the water is cleansed. The objectives of this study were to identify through a bibliometric analysis (2000−2022) the main OFP that have been used in CWs and their functionality as phytoremediators (removal effects), as well as the authors, collaborations, main investigations, and the countries where such investigations have been carried out. To this respect, 10,254 studies on CWs were identified. The United States and China were the leading countries in the use of this eco-technology. Subsequently, regarding the use of OFP, the analysis revealed 92 studies on this matter in which Mexico has three resea... [more]
Comprehensive Experimental and Numerical Optimization of Diesel Engine Thermal Management Strategy for Emission Clarification and Carbon Dioxide Control
Da Li, Sipeng Zhu, Guodong Zhang, Ke Sun, Shuzhan Bai, Guoxiang Li, Hao Cheng
April 28, 2023 (v1)
Keywords: aftertreatment, diesel engine, thermal management, waste heat recovery
Improving the thermal efficiency of truck diesel engines requires comprehensive optimization of the engine, exhaust aftertreatment (EAT), and possible waste heat recovery (WHR). Lower exhaust temperature at mid and low working points has caused difficulty in both emission clarification and heat recovery, which requires thermal management. Based on the diesel engine bench test and separate bench tests, this paper focuses on the thermal management strategy optimization, to increase the exhaust temperature at lower working points and optimize the thermal efficiency of the whole system. The test and numerical analysis showed that as exhaust temperature increased from 200~250 °C to 300~350 °C, soot passive regeneration reactions were enhanced, nitrogen oxide emission decreased, and energy recovery was improved. Moderate throttle valve adjustment coupled with early post injection could effectively achieve the required temperature increase. The optimized thermal management strategy increased... [more]
Carbon Accounting of Weihe CSA Pilot Demonstration Area in Longjiang Forest Industry
Kexin Ma, Meiyun Geng, Lidong Han, Qingfang Sun, Leihao Zhang, Zekai Yang, Yue Tang, Sihan Guo, Yufei Xiao, Di Zhang, Xiaotang Wo
April 28, 2023 (v1)
Subject: Environment
Keywords: carbon accounting, carbon sink afforestation, demonstration area, forest industry
Carbon sink afforestation (CSA) has become one of the most concerned issues of countries around the world under the background of climate change. The northern forest ecosystem, located in mid- and high latitudes, is a huge terrestrial carbon pool and is very sensitive to climate change. Studying the carbon emission accounting of CSA in northern forests helps clarify the contribution of CSA to forestry carbon sequestration and forecasts the carbon sink effect of forest ecosystems. It is of great significance for the assessment of forest carbon sink and carbon cycling by providing a scientific basis and reference for the development, utilization, and management of carbon sink afforestation, as well as the coordinated development of ecology and social economy. At present, research on the carbon emission accounting of the CSA in northern China is still lacking. According to the relevant models and parameters of estimating live biomasses with the default method from the IPCC’s (Intergovernm... [more]
Titanium(III) Oxide Doped with meta-Aminophenol Formaldehyde Magnetic Microspheres: Enhancing Dye Adsorption toward Methyl Violet
Suriyan Radha, Paul Christygnanatheeba, Karuppiah Nagaraj, Saradh Prasad, Mohamad Saleh AlSalhi, Jeyaraj Vinoth Kumar, Prabhakarn Arunachalam, Chelladurai Karuppiah
April 28, 2023 (v1)
Subject: Materials
Keywords: formaldehyde, magnetic microspheres, meta-aminophenol, methyl violet, Ti2O3 nanoparticles
The demand to synthesize economical detoxification adsorbents of organic pollutants has been a thriving solicitude for most environmental research aspirants. Here, we synthesized a titanium(III) oxide doped with spherical shaped meta-aminophenol formaldehyde magnetic microspheres (Ti2O3/mAPF MMSs) by the polymerization method of Ti2O3 nanoparticles with formaldehyde and m-aminophenol. SEM analysis confirmed the synthesized material as crystalline in nature and had ~400−450 nm sized particles. The physical characterization of the Ti2O3/mAPF MMSs were quantitatively revealed by FTIR spectrum and PXRD in elaboration. The carboxylate frequency and the characteristic apex of the titanium−oxygen bond was found in the FTIR spectrum for Ti2O3/mAPF derived from Ti2O3. The PXRD patterns proved that the synthesized magnetic microspheres contained Ti2O3 nanoparticles. The experimental methods of TGA and DTA confirmed the thermal stability and its composition of Ti2O3/mAPF MMSs. The kinetic adsorpt... [more]
The Application of Hyperspectral Images in the Classification of Fresh Leaves’ Maturity for Flue-Curing Tobacco
Xiaochong Lu, Chen Zhao, Yanqing Qin, Liangwen Xie, Tao Wang, Zhiyong Wu, Zicheng Xu
April 28, 2023 (v1)
Keywords: characteristic spectral bands, classification, flue-cured tobacco leaves, hyperspectral image, maturity
The maturity of tobacco leaves directly affects their curing quality. However, no effective method has been developed for determining their maturity during production. Assessment of tobacco maturity for flue curing has long depended on production experience, leading to considerable variation. In this study, hyperspectral imaging combined with a novel algorithm was used to develop a classification model that could accurately determine the maturity of tobacco leaves. First, tobacco leaves of different maturity levels (unripe, under-ripe, ripe, and over-ripe) were collected. ENVI software was used to remove the hyperspectral imaging (HSI) background, and 11 groups of filtered images were obtained using Python 3.7. Finally, a full-band-based partial least-squares discriminant analysis (PLS-DA) classification model was established to identify the maturity of the tobacco leaves. In the calibration set, the model accuracy of the original spectrum was 88.57%, and the accuracy of the de-trendin... [more]
A Three-Phase Relative Permeability Model for Heavy Oil Emulsion System
Zezheng Sun, Kang Zhou, Yuan Di
April 28, 2023 (v1)
Keywords: chemical flood, dispersed system, emulsion, enhanced oil recovery, porous flow, relative permeability
Chemical flooding is important and effective enhanced oil recovery processes are applied to improve the recovery of heavy oil reservoirs. Emulsification occurs during chemical flooding processes, forming an oil-in-water (O/W) emulsion system. In this work, the heavy oil emulsion system is characterized as a three-phase (continuous oil phase, dispersed oil phase, and continuous water phase) system. Based on a capillary tube model, a new relative permeability model is proposed to describe the flow of the emulsion system in porous media quantitatively, considering the physicochemical properties of emulsions and the properties of porous media. A resistance factor is derived in this model to describe the additional resistance to the emulsion flow caused by the interaction between dispersed oil droplets and the pore system. Three dimensionless numbers related to the emulsion porous flow process were proposed and their different effects on the three-phase relative permeability are investigate... [more]
Investigation on the Dynamics of a Flexible Multi-Body System of a Three-Cylinder Gasoline Engine Crankshaft
Xiao Zhang, Lu Zheng
April 28, 2023 (v1)
Keywords: engine crankshaft system, fuel economy, three-cylinder gasoline engines
Three-cylinder gasoline engines are increasingly favored by major automobile manufacturers due to their good fuel economy, low manufacturing cost and low fuel consumption. However, the inherent balance problem has an adverse effect on the vibration of the whole engine and even the comfort of the whole vehicle, which limits its application in high-end models. This paper studied the dynamics characteristic of the flexible multi-body system of the three-cylinder gasoline engine crankshaft. A dynamic simulation model of the flexible multi-body system of the three-cylinder gasoline engine crankshaft is established through the flexible treatment of the engine crankshaft. The kinematics and dynamics characteristics of each component of the crankshaft connecting rod system are obtained by analyzing the kinematics and dynamics characteristics of the engine shafting system. The relevant factors affecting the vibration of the engine crankshaft system are studied through the establishment of the a... [more]
Shewhart Control Charts Implementation for Quality and Production Management
Marcela Malindzakova, Katarína Čulková, Jarmila Trpčevská
April 28, 2023 (v1)
Keywords: Pearson test, production stabilization, quality marks, Shewhart control charts, variability control
Shewhart control charts are suitable for stable but repetitive production processes used for the subsequent identification of random deviations while indicating breached quality limits. They provide information on process variability and, at the same time, make it possible to obtain information on the reliability of monitored processes. The objective of this paper is to assess the quality characteristics of plastic mouldings for the needs of the automotive industry with the application of the control charts method, specifically Shewhart control charts. The Shewhart control charts were applied to evaluate the quality characteristics, or, more specifically, to evaluate the measured width and length of the produced plastic mouldings by statistical analysis. Statistical analyses show that the set parameters are not met in the first two days of the test series. An improvement in the process is observed on the last day of the test series. The process is well set, as confirmed by our verifica... [more]
Unusual Water Flow in Ultra-Tight Porous Media: Integration of Profession and Innovation
Yanglu Wan, Na Niu, Wei Lu, Yushuang Zhou, Bin Wang, Shan Lu
April 28, 2023 (v1)
Keywords: nanoconfinement, pore network, Simulation, viscosity, wettability
Hydraulic fracturing is an effective method for stimulating reservoirs, making the economic development of ultra-tight shale gas and coalbed methane reservoirs possible. These formations are rich in nanopores, in which the fracturing fluid, such as fresh water, the flow, and the behavior of this flow differ significantly from those described in the classic Navier-Stokes formula. In bulk space, the interaction force exerted by the solid phase can be ignored, but the solid−fluid interaction plays a dominant role in nanoconfinement spaces in which the pore size is comparable to the molecular diameter. Nanoconfined water molecules tend to approach the water-wet pore surface, enhancing the water viscosity, which is a key parameter affecting the water flow capacity. Conversely, water molecules tend to stay in the middle of nanopores when subjected to a hydrophobic surface, leading to a decrease in viscosity. Thus, nanoconfined water viscosity is a function of the strength of the surface−flui... [more]
Multi-Point Flux MFE Decoupled Method for Compressible Miscible Displacement Problem
Wenwen Xu, Hong Guo, Xindong Li, Yongqiang Ren
April 28, 2023 (v1)
Keywords: compressible miscible displacement, decoupled method, error analysis, multi-point flux MFE, numerical experiments
In this paper, a multi-point flux mixed-finite-element decoupled method was considered for the compressible miscible displacement problem. For this compressible problem, a fully discrete backward Euler scheme was proposed, in which the velocity and pressure equations were decoupled by a multi-point flux MFE method using BDM1 elements combined with a trapezoidal quadrature rule. The concentration equation was handled by a standard FE method. The error analysis for velocity, pressure, and concentration were rigorously derived. Numerical experiments to verify the convergence rates and simulate the miscible displacement problem of a water−oil system were presented.
Microwave-Assisted Phytochemical Extraction from Walnut Hull and Process Optimization Using Box−Behnken Design (BBD)
Rahul Singh, Poornima Singh, Vinay Kumar Pandey, Kshirod Kumar Dash, Ashish, Shaikh Ayaz Mukarram, Endre Harsányi, Béla Kovács
April 28, 2023 (v1)
Keywords: antioxidant, conventional method, microwave-assisted extraction, walnut hull
The walnut green hull is an agro-waste, a source of natural dye and volatile compounds with various biological activities, but the main challenge with the conventional extraction method is the quality and quantity of the volatile compound (dye) extraction from walnut hull waste. The objective of this research work is to use microwave-assisted extraction (MAE) as an emerging technology. Further, the MAE process was optimized using a Box−Behnken Design (BBD) of response surface methodology (RSM). The variables in MAE process optimization were microwave power, microwave time, solvent volume, and raw material particle size. The result indicated that MAE produces a higher extraction yield compared to the conventional method. The RSM analyses showed an increase in extract yield, total phenolic content, and total flavonoid content, along with antioxidant activity. The optimized condition parameters of MAE were reported to be 363.64-watt microwave power, 3.133 min, 39.999 mL/g solvent volume,... [more]
A Method of Reducing Friction and Improving the Penetration Rate by Safely Vibrating the Drill-String at Surface
Yuan Long, Xueying Wang, Peng Wang, Feifei Zhang
April 28, 2023 (v1)
Keywords: drill-string mechanics, friction reduction, petroleum drilling, vibration
Drill-string axial vibration at the surface technology is proposed to reduce the friction between the drill-string and the borehole wall, and to improve load transfer efficiency, the rate of penetration (ROP), and the extended-reach limit of a horizontal well. An analytical framework utilizing the “soft-string” model is constructed. The results obtained from numerical simulations reveal that during the slide drilling operation, the drill-string experiences an axial stick−slip motion, and the weight on bit (WOB) undergoes periodic oscillations. The conventional calibration method of the WOB in the weight indicator gauge is not applicable when the ROP is low. After applying axial vibration on the drill-string at the surface, the WOB increases and becomes smooth because of a release of friction. The amplitude and frequency of the exciting force are the main factors affecting surface vibration effectiveness. There is an optimal frequency for a given case (10 Hz in this paper). This means t... [more]
Circuit Breaker Fault Diagnosis Method Based on Coil Current Time Sequence Phase Trajectory Characteristics
Yaqi Chen, Qiong Li, Yang Zou, Guohua Long, Nianping Yan, Ruixiang Fan
April 28, 2023 (v1)
Keywords: breaking coil current signal, circuit breaker, first-order forward differencing, phase space reconstruction, phase trajectory
The traditional circuit breaker fault diagnosis method suffers from insufficient feature information extraction and is easily affected by abnormal signal acquisition. To address this, this paper introduces the phase space reconstruction algorithm to reconstruct the current signal for fault diagnosis based on phase trajectory features. The proposed method uses a first-order forward differencing method and mutual information method to process abnormal data and select the parameters of the reconstruction, then extract overall and local inflection point features to construct a fault feature set. The support vector machine algorithm-based model is trained and tested using actual samples, and the results show that the proposed method can adaptively sample anomalous signals, exhibit strong robustness, and significantly improve the accuracy of fault classification.
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