Mathematical models and numerical simulations are necessary to understand the dynamical behaviors of complex systems. The aim of this work is to investigate closed-form solutions for the ball–plate problem considering a system derived from an optimal control problem for ball–plate dynamics. The nonlinear properties of ball and plate control system are presented in this work. To semi-analytically solve this system, we explored a second-order nonlinear differential equation. Consequently, we obtained the approximate closed-form solutions by the Optimal Parametric Iteration Method (OPIM) using only one iteration. A comparison between the analytical and corresponding numerical procedures reflects the advantages of the first one. The accordance between the obtained results and the numerical ones highlights that the procedure used is accurate, effective, and good to implement in applications such as sliding mode control to the ball-and-plate problem.
{"title":"Semi-Analytical Closed-Form Solutions of the Ball–Plate Problem","authors":"Remus-Daniel Ene, Nicolina Pop","doi":"10.3390/pr12091977","DOIUrl":"https://doi.org/10.3390/pr12091977","url":null,"abstract":"Mathematical models and numerical simulations are necessary to understand the dynamical behaviors of complex systems. The aim of this work is to investigate closed-form solutions for the ball–plate problem considering a system derived from an optimal control problem for ball–plate dynamics. The nonlinear properties of ball and plate control system are presented in this work. To semi-analytically solve this system, we explored a second-order nonlinear differential equation. Consequently, we obtained the approximate closed-form solutions by the Optimal Parametric Iteration Method (OPIM) using only one iteration. A comparison between the analytical and corresponding numerical procedures reflects the advantages of the first one. The accordance between the obtained results and the numerical ones highlights that the procedure used is accurate, effective, and good to implement in applications such as sliding mode control to the ball-and-plate problem.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liposome-based drug carriers are multipurpose colloidal drug delivery systems developed mainly for targeted therapy. Researchers have expanded their research on liposomes due to their unique characteristics (e.g., non-toxicity, biodegradability, biocompatibility, and non-immunogenicity). This review summarizes historical advances, from the first scientific papers and patents to the latest inventive solutions, in the field of liposome-based drug carriers and their production processes. Various bibliometric studies on the use of liposomes as drug carriers have been published; nevertheless, they focus on published scientific works rather than patent documents. Patent information is important for the pharmaceutical, nutraceutical, and cosmetic industries because technical knowledge in patent documentation is often not published in any other document. The research in this review was conducted using the Espacenet—European Patent Office database, with keywords and classification codes defined by the International Patent Classification. Innovative formulations, including the usage and administration route, are broadly researched to produce effective and safe drug delivery systems with negligible side effects. Global patenting trends in liposome drug carriers’ production process were also discussed, and this evaluation unifies up-to-date development in this field. Patent database reviews and analyses could help as inspiration for future investigations as well as for problem-solving resources.
{"title":"Innovative and Patented Liposome-Based Drug Carriers","authors":"Snežana Ilić-Stojanović, Suzana Cakić, Nada Nikolić, Slobodan Petrović","doi":"10.3390/pr12091970","DOIUrl":"https://doi.org/10.3390/pr12091970","url":null,"abstract":"Liposome-based drug carriers are multipurpose colloidal drug delivery systems developed mainly for targeted therapy. Researchers have expanded their research on liposomes due to their unique characteristics (e.g., non-toxicity, biodegradability, biocompatibility, and non-immunogenicity). This review summarizes historical advances, from the first scientific papers and patents to the latest inventive solutions, in the field of liposome-based drug carriers and their production processes. Various bibliometric studies on the use of liposomes as drug carriers have been published; nevertheless, they focus on published scientific works rather than patent documents. Patent information is important for the pharmaceutical, nutraceutical, and cosmetic industries because technical knowledge in patent documentation is often not published in any other document. The research in this review was conducted using the Espacenet—European Patent Office database, with keywords and classification codes defined by the International Patent Classification. Innovative formulations, including the usage and administration route, are broadly researched to produce effective and safe drug delivery systems with negligible side effects. Global patenting trends in liposome drug carriers’ production process were also discussed, and this evaluation unifies up-to-date development in this field. Patent database reviews and analyses could help as inspiration for future investigations as well as for problem-solving resources.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chaofeng Chen, Xihe Liu, Dong Ruan, Xueru Chen, Xiangtong Yang, Kun Ning, Zhilong Lian
With advancements in the exploration and development of deep and ultra-deep oil and gas resources, the number of ultra-deep wells continues to rise globally. This trend places higher demands on testing technology. The combined perforating and testing technique, an established method for deep and ultra-deep wells, faces challenges. Frequent test operation failures due to perforation detonation failure increase down-hole complexity, restricting the timeliness of testing operations. Current methods use mechanical calibration software to calculate the minimum safety factor of the tubing string for safety assessments. However, without a thorough understanding of perforation detonation failure theory, existing mechanical analysis software remains unreliable for assessing well safety during operations. Simply using the safety factor method lacks reliability and cannot explain the causes of perforation detonation failure. This paper examines an ultra-deep well, referred to as TW1, to analyze perforation detonation failure mechanisms. Through metal microstructure examinations, chemical composition analysis, electron microscope scanning, and numerical simulation, the study yields the following insights: (1) The packer mandrel of Well TW1 fractured due to overstress from the detonation waves. (2) Detonation wave propagation patterns along the tubing string during perforation become apparent. (3) Simulation methods reconstruct the perforation detonation process, calculating effective stress at different tubing string positions over time. (4) It introduces an innovative approach for assessing perforation detonation failure mechanisms through a combination of laboratory testing and simulation modeling.
{"title":"Understanding Perforation Detonation Failure Mechanisms Based on Physicochemical Detection and Simulation Modeling","authors":"Chaofeng Chen, Xihe Liu, Dong Ruan, Xueru Chen, Xiangtong Yang, Kun Ning, Zhilong Lian","doi":"10.3390/pr12091971","DOIUrl":"https://doi.org/10.3390/pr12091971","url":null,"abstract":"With advancements in the exploration and development of deep and ultra-deep oil and gas resources, the number of ultra-deep wells continues to rise globally. This trend places higher demands on testing technology. The combined perforating and testing technique, an established method for deep and ultra-deep wells, faces challenges. Frequent test operation failures due to perforation detonation failure increase down-hole complexity, restricting the timeliness of testing operations. Current methods use mechanical calibration software to calculate the minimum safety factor of the tubing string for safety assessments. However, without a thorough understanding of perforation detonation failure theory, existing mechanical analysis software remains unreliable for assessing well safety during operations. Simply using the safety factor method lacks reliability and cannot explain the causes of perforation detonation failure. This paper examines an ultra-deep well, referred to as TW1, to analyze perforation detonation failure mechanisms. Through metal microstructure examinations, chemical composition analysis, electron microscope scanning, and numerical simulation, the study yields the following insights: (1) The packer mandrel of Well TW1 fractured due to overstress from the detonation waves. (2) Detonation wave propagation patterns along the tubing string during perforation become apparent. (3) Simulation methods reconstruct the perforation detonation process, calculating effective stress at different tubing string positions over time. (4) It introduces an innovative approach for assessing perforation detonation failure mechanisms through a combination of laboratory testing and simulation modeling.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current study investigates the development of a replica molding process for hypervariable microstructures. Initially, the mold deformation theory for these hypervariable microstructures was derived. Based on this theory, a metal material with magnetic properties was selected as the structural material to create a negative Poisson’s ratio (NPR) geometric structure. The experimental results, obtained by fabricating the NPR geometric mold layer with a metal material with adjustable magnetic properties and controlling microstructure deformation indirectly, validate the deformation theory and its predictions. These results demonstrate that the developed molding process, integrated with the magnetic NPR regulation system, exhibits excellent stability and replication capability. In this study, at the zero height (z = 0) position on the interface between the NPR geometric structure layer and the Polydimethylsiloxane (PDMS), the variation becomes more pronounced with increasing distance from the center of the microstructure. Furthermore, the tendency of the function curve varies accordingly. The primary cause is the lack of constraints on the free ends of both sides and the excessive constraints on the intermediate parts. Under the conditions in this study, the maximum ratio of its influence on the radial diameter thickness was 2.1%. This innovative process facilitates the rapid imprinting of microstructural components and offers the advantage of efficient molding.
{"title":"Development of Replica Molding Processes for Hypervariable Microstructural Components","authors":"Yung-Jin Weng, Yu-Zhe Gao, Yu-Ming Chen","doi":"10.3390/pr12091968","DOIUrl":"https://doi.org/10.3390/pr12091968","url":null,"abstract":"The current study investigates the development of a replica molding process for hypervariable microstructures. Initially, the mold deformation theory for these hypervariable microstructures was derived. Based on this theory, a metal material with magnetic properties was selected as the structural material to create a negative Poisson’s ratio (NPR) geometric structure. The experimental results, obtained by fabricating the NPR geometric mold layer with a metal material with adjustable magnetic properties and controlling microstructure deformation indirectly, validate the deformation theory and its predictions. These results demonstrate that the developed molding process, integrated with the magnetic NPR regulation system, exhibits excellent stability and replication capability. In this study, at the zero height (z = 0) position on the interface between the NPR geometric structure layer and the Polydimethylsiloxane (PDMS), the variation becomes more pronounced with increasing distance from the center of the microstructure. Furthermore, the tendency of the function curve varies accordingly. The primary cause is the lack of constraints on the free ends of both sides and the excessive constraints on the intermediate parts. Under the conditions in this study, the maximum ratio of its influence on the radial diameter thickness was 2.1%. This innovative process facilitates the rapid imprinting of microstructural components and offers the advantage of efficient molding.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The study of the flexible job shop scheduling problem (FJSP) is of great importance in the context of green manufacturing. In this paper, with the optimization objectives of minimizing the maximum completion time and the total machine energy consumption, an improved multi-objective evolutionary algorithm with decomposition (MOEA/D) based on reinforcement learning is proposed. Firstly, three initialization strategies are used to generate the initial population in a certain ratio, and four variable neighborhood search strategies are combined to increase the local search capability of the algorithm. Second, a parameter adaptation strategy based on Q-learning is proposed to guide the population to select the optimal parameters to increase diversity. Finally, the performance of the proposed algorithm is analyzed and evaluated by comparing Q-MOEA/D with IMOEA/D and NSGA-II through different sizes of Kacem and BRdata benchmark cases and production examples of automotive engine cooling system manufacturing. The results show that the Q-MOEA/D algorithm outperforms the other two algorithms in solving the energy-efficient scheduling problem for flexible job shops.
{"title":"An Enhanced Multi-Objective Evolutionary Algorithm with Reinforcement Learning for Energy-Efficient Scheduling in the Flexible Job Shop","authors":"Jinfa Shi, Wei Liu, Jie Yang","doi":"10.3390/pr12091976","DOIUrl":"https://doi.org/10.3390/pr12091976","url":null,"abstract":"The study of the flexible job shop scheduling problem (FJSP) is of great importance in the context of green manufacturing. In this paper, with the optimization objectives of minimizing the maximum completion time and the total machine energy consumption, an improved multi-objective evolutionary algorithm with decomposition (MOEA/D) based on reinforcement learning is proposed. Firstly, three initialization strategies are used to generate the initial population in a certain ratio, and four variable neighborhood search strategies are combined to increase the local search capability of the algorithm. Second, a parameter adaptation strategy based on Q-learning is proposed to guide the population to select the optimal parameters to increase diversity. Finally, the performance of the proposed algorithm is analyzed and evaluated by comparing Q-MOEA/D with IMOEA/D and NSGA-II through different sizes of Kacem and BRdata benchmark cases and production examples of automotive engine cooling system manufacturing. The results show that the Q-MOEA/D algorithm outperforms the other two algorithms in solving the energy-efficient scheduling problem for flexible job shops.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aida Aguilera Infante-Neta, Alan Portal D’Almeida, Tiago Lima de Albuquerque
The scientific community has explored new packaging materials owing to environmental challenges and pollution from plastic waste. Bacterial cellulose (BC), produced by bacteria like Gluconacetobacter xylinus, shows high potential for food preservation owing to its exceptional mechanical strength, high crystallinity, and effective barrier properties against gases and moisture, making it a promising alternative to conventional plastics. This review highlights recent advances in BC production, particularly agro-industrial residues, which reduce costs and enhance environmental sustainability. Incorporating antimicrobial agents into BC matrices has also led to active packaging solutions that extend food shelf-life and improve safety. A bibliometric analysis reveals a significant increase in research on BC over the last decade, reflecting growing global interest. Key research themes include the development of BC-based composites and the exploration of their antimicrobial properties. Critical areas for future research include improving BC production’s scalability and economic viability and the integration of BC with other biopolymers. These developments emphasize BC’s potential as a sustainable packaging material and its role in the circular economy through waste valorization.
由于塑料废弃物带来的环境挑战和污染，科学界一直在探索新的包装材料。由 Gluconacetobacter xylinus 等细菌产生的细菌纤维素（Bacterial cellulose，BC）具有极高的机械强度、高结晶度以及有效阻隔气体和湿气的特性，因此在食品保鲜方面显示出巨大潜力，有望成为传统塑料的替代品。本综述重点介绍了不饱和脂肪酸生产方面的最新进展，特别是农用工业残留物方面的进展，这些进展既降低了成本，又提高了环境的可持续性。在 BC 基质中加入抗菌剂也带来了可延长食品保质期和提高安全性的活性包装解决方案。文献计量分析表明，在过去十年中，有关不饱和脂肪酸的研究显著增加，反映出全球对不饱和脂肪酸的兴趣与日俱增。关键的研究主题包括开发以 BC 为基础的复合材料和探索其抗菌特性。未来研究的关键领域包括提高萃取物生产的可扩展性和经济可行性，以及萃取物与其他生物聚合物的整合。这些发展强调了 BC 作为可持续包装材料的潜力，以及其通过废物价值化在循环经济中的作用。
{"title":"Bacterial Cellulose in Food Packaging: A Bibliometric Analysis and Review of Sustainable Innovations and Prospects","authors":"Aida Aguilera Infante-Neta, Alan Portal D’Almeida, Tiago Lima de Albuquerque","doi":"10.3390/pr12091975","DOIUrl":"https://doi.org/10.3390/pr12091975","url":null,"abstract":"The scientific community has explored new packaging materials owing to environmental challenges and pollution from plastic waste. Bacterial cellulose (BC), produced by bacteria like Gluconacetobacter xylinus, shows high potential for food preservation owing to its exceptional mechanical strength, high crystallinity, and effective barrier properties against gases and moisture, making it a promising alternative to conventional plastics. This review highlights recent advances in BC production, particularly agro-industrial residues, which reduce costs and enhance environmental sustainability. Incorporating antimicrobial agents into BC matrices has also led to active packaging solutions that extend food shelf-life and improve safety. A bibliometric analysis reveals a significant increase in research on BC over the last decade, reflecting growing global interest. Key research themes include the development of BC-based composites and the exploration of their antimicrobial properties. Critical areas for future research include improving BC production’s scalability and economic viability and the integration of BC with other biopolymers. These developments emphasize BC’s potential as a sustainable packaging material and its role in the circular economy through waste valorization.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhongzong Cao, Honglin Liu, Chengfang Shan, Hongzhi Wang, Haitong Kang
In the process of roadway excavation in thick and hard coal seams with a hard roof, the instantaneous release of a large amount of elastic energy accumulated in coal and rock mass causes disasters. Especially under the action of tectonic stress, dynamic disasters of roadway-surrounding rock are extremely strong. Therefore, this paper takes the 110,505 roadway of the Yushuling Coal Mine as the engineering background. Aiming at the serious deformation of roadway-surrounding rock and the problem of strong mine pressure, the deformation mechanism of roadway-surrounding rock is studied by means of theoretical analysis, indoor experimentation, numerical simulation and field testing, and the surrounding rock control technology is proposed. Firstly, the results show that the stress field type of the Yushuling Coal Mine is a σHv type, the azimuth angle of the maximum horizontal principal stress is concentrated in 110.30°~114.12°, the dip angle is −33.04°~−3.43°, and the maximum horizontal principal stress is 1.94~2.76 times of the minimum horizontal principal stress. Secondly, the brittleness index of No. 5 is 0.62; the failure energy release of the surrounding rock compressive energy floor rock sample is up to 150,000 mv * ms. The more the cumulative number of rock samples, the greater the strength, and the more severe the damage. Thirdly, with the increase in tectonic stress, the stress of roadway-surrounding rock is asymmetrically distributed, and the plastic zone develops along the tendency. The maximum range of the plastic zone expands from 4.18 m to 10.19 m. Lastly, according to the deformation characteristics of roadway-surrounding rock, left side > roof > right side > floor, the surrounding rock control technology of ‘asymmetric anchor net cable support + borehole pressure relief’ is proposed, which realizes the effective control of roadway-surrounding rock deformation.
{"title":"Surrounding Rock Control Technology of Thick Hard Roof and Hard Coal Seam Roadway under Tectonic Stress","authors":"Zhongzong Cao, Honglin Liu, Chengfang Shan, Hongzhi Wang, Haitong Kang","doi":"10.3390/pr12091973","DOIUrl":"https://doi.org/10.3390/pr12091973","url":null,"abstract":"In the process of roadway excavation in thick and hard coal seams with a hard roof, the instantaneous release of a large amount of elastic energy accumulated in coal and rock mass causes disasters. Especially under the action of tectonic stress, dynamic disasters of roadway-surrounding rock are extremely strong. Therefore, this paper takes the 110,505 roadway of the Yushuling Coal Mine as the engineering background. Aiming at the serious deformation of roadway-surrounding rock and the problem of strong mine pressure, the deformation mechanism of roadway-surrounding rock is studied by means of theoretical analysis, indoor experimentation, numerical simulation and field testing, and the surrounding rock control technology is proposed. Firstly, the results show that the stress field type of the Yushuling Coal Mine is a σHv type, the azimuth angle of the maximum horizontal principal stress is concentrated in 110.30°~114.12°, the dip angle is −33.04°~−3.43°, and the maximum horizontal principal stress is 1.94~2.76 times of the minimum horizontal principal stress. Secondly, the brittleness index of No. 5 is 0.62; the failure energy release of the surrounding rock compressive energy floor rock sample is up to 150,000 mv * ms. The more the cumulative number of rock samples, the greater the strength, and the more severe the damage. Thirdly, with the increase in tectonic stress, the stress of roadway-surrounding rock is asymmetrically distributed, and the plastic zone develops along the tendency. The maximum range of the plastic zone expands from 4.18 m to 10.19 m. Lastly, according to the deformation characteristics of roadway-surrounding rock, left side > roof > right side > floor, the surrounding rock control technology of ‘asymmetric anchor net cable support + borehole pressure relief’ is proposed, which realizes the effective control of roadway-surrounding rock deformation.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explores the adsorption of Pb(II) from aqueous solutions using glutathione-modified carbon powder at room temperature. The graphite powder was modified through oxidation followed by surface immobilization of glutathione. The Pb(II) concentration was measured using square wave anodic stripping voltammetry (SWASV). Experiments were conducted with the following varying initial Pb(II) ion concentrations: 20.72 mg L−1, 41.44 mg L−1, 62.16 mg L−1, 82.88 mg L−1, 103.60 mg L−1, and 124.32 mg L−1. The effect of varying the glutathione-modified carbon powder dosage (12.5 mg, 25.0 mg, 50.0 mg, 75.0 mg, and 100.0 mg) on Pb(II) uptake was studied. The adsorption data were modeled using the Freundlich isotherm, resulting in a regression coefficient (R2) of 0.96, which signifies a good fit. The Freundlich constants obtained were KF = 3.54 × 10−5 (adsorption capacity) and n = 1.56 (adsorption intensity). At optimal conditions (10.0 mL of 20.72 mg L−1 Pb(II) solution with 100.0 mg of glutathione-modified carbon powder), the adsorption efficiency was 96.3%. The glutathione-modified carbon powder exhibits a high capacity for adsorbing Pb(II) from aqueous solutions.
{"title":"Lead Ion Adsorption on Glutathione-Modified Carbon","authors":"Namasivayam Selvanantharajah, Poobalasuntharam Iyngaran, Poobalasingam Abiman, Navaratnarajah Kuganathan","doi":"10.3390/pr12091972","DOIUrl":"https://doi.org/10.3390/pr12091972","url":null,"abstract":"This study explores the adsorption of Pb(II) from aqueous solutions using glutathione-modified carbon powder at room temperature. The graphite powder was modified through oxidation followed by surface immobilization of glutathione. The Pb(II) concentration was measured using square wave anodic stripping voltammetry (SWASV). Experiments were conducted with the following varying initial Pb(II) ion concentrations: 20.72 mg L−1, 41.44 mg L−1, 62.16 mg L−1, 82.88 mg L−1, 103.60 mg L−1, and 124.32 mg L−1. The effect of varying the glutathione-modified carbon powder dosage (12.5 mg, 25.0 mg, 50.0 mg, 75.0 mg, and 100.0 mg) on Pb(II) uptake was studied. The adsorption data were modeled using the Freundlich isotherm, resulting in a regression coefficient (R2) of 0.96, which signifies a good fit. The Freundlich constants obtained were KF = 3.54 × 10−5 (adsorption capacity) and n = 1.56 (adsorption intensity). At optimal conditions (10.0 mL of 20.72 mg L−1 Pb(II) solution with 100.0 mg of glutathione-modified carbon powder), the adsorption efficiency was 96.3%. The glutathione-modified carbon powder exhibits a high capacity for adsorbing Pb(II) from aqueous solutions.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hubin Du, Qiuyu Li, Ziqian Guan, Hengyuan Zhang, Yongtao Liu
The efficacy of early fire detection hinges on its swift response and precision, which allows for the issuance of timely alerts in the nascent stages of a fire, thereby minimizing losses and injuries. To enhance the precision and swiftness of identifying minute early flame targets, as well as the ease of deployment at the edge end, an optimized early flame target detection algorithm for YOLOv8 is proposed. The original feature fusion module, an FPN (feature pyramid network) of YOLOv8n, has been enhanced to become the BiFPN (bidirectional feature pyramid network) module. This modification enables the network to more efficiently and rapidly perform multi-scale fusion, thereby enhancing its capacity for integrating features across different scales. Secondly, the efficient multi-scale attention (EMA) mechanism is introduced to ensure the effective retention of information on each channel and reduce the computational overhead, thereby improving the model’s detection accuracy while reducing the number of model parameters. Subsequently, the NWD (normalized Wasserstein distance) loss function is employed as the bounding box loss function, which enhances the model’s regression performance and robustness. The experimental results demonstrate that the size of the enhanced model is 4.8 M, a reduction of 22.5% compared to the original YOLOv8n. Additionally, the mAP0.5 metric exhibits a 2.7% improvement over the original YOLOv8n, indicating a more robust detection capability and a more compact model size. This makes it an ideal candidate for deployment in edge devices.
{"title":"An Improved Lightweight YOLOv8 Network for Early Small Flame Target Detection","authors":"Hubin Du, Qiuyu Li, Ziqian Guan, Hengyuan Zhang, Yongtao Liu","doi":"10.3390/pr12091978","DOIUrl":"https://doi.org/10.3390/pr12091978","url":null,"abstract":"The efficacy of early fire detection hinges on its swift response and precision, which allows for the issuance of timely alerts in the nascent stages of a fire, thereby minimizing losses and injuries. To enhance the precision and swiftness of identifying minute early flame targets, as well as the ease of deployment at the edge end, an optimized early flame target detection algorithm for YOLOv8 is proposed. The original feature fusion module, an FPN (feature pyramid network) of YOLOv8n, has been enhanced to become the BiFPN (bidirectional feature pyramid network) module. This modification enables the network to more efficiently and rapidly perform multi-scale fusion, thereby enhancing its capacity for integrating features across different scales. Secondly, the efficient multi-scale attention (EMA) mechanism is introduced to ensure the effective retention of information on each channel and reduce the computational overhead, thereby improving the model’s detection accuracy while reducing the number of model parameters. Subsequently, the NWD (normalized Wasserstein distance) loss function is employed as the bounding box loss function, which enhances the model’s regression performance and robustness. The experimental results demonstrate that the size of the enhanced model is 4.8 M, a reduction of 22.5% compared to the original YOLOv8n. Additionally, the mAP0.5 metric exhibits a 2.7% improvement over the original YOLOv8n, indicating a more robust detection capability and a more compact model size. This makes it an ideal candidate for deployment in edge devices.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benabderrahmane Farhat, Noureddine Kaid, Sultan Alqahtani, Younes Menni, Badr M. Alshammari, Lioua Kolsi
This study delves into the convective heat transfer phenomena within a square cavity that houses a porous medium, analyzing the effects of Darcy (Da) and Rayleigh (Ra) numbers on the thermal and fluid dynamic behavior within the system. Utilizing a combination of computational fluid dynamics (CFD) and the finite element method (FEM), the research focuses on steady-state, laminar flow conditions in two dimensions. The cavity, which is impermeable at its boundaries, contains a centrally located square region filled with a porous, isotropic material. The thermal environment is controlled with insulated horizontal walls and vertically positioned walls that experience sinusoidal temperature variations. The study examines how variations in the permeability of the porous medium (Da numbers ranging from 10−1 to 10−4) and the buoyancy-driven flow strength (Ra numbers spanning from 102 to 105) influence the velocity fields and heat transfer rates, with results expressed through Nusselt number (Nu) distributions. The findings reveal that higher Ra numbers, particularly at 105, significantly intensify convection within the cavity, thereby boosting local rates of heat transfer, especially in the central vertical section. The research identifies that optimal flow resistance in the porous medium occurs within the Da number range of 10−3 to 10−4. These insights are critical for advancing thermal management techniques, particularly in the natural cooling of electronic devices and improving insulation methods.
{"title":"Finite Element Analysis of Laminar Natural Convection in a Differentially Heated Porous Cavity Using the Darcy–Brinkman Model","authors":"Benabderrahmane Farhat, Noureddine Kaid, Sultan Alqahtani, Younes Menni, Badr M. Alshammari, Lioua Kolsi","doi":"10.3390/pr12091974","DOIUrl":"https://doi.org/10.3390/pr12091974","url":null,"abstract":"This study delves into the convective heat transfer phenomena within a square cavity that houses a porous medium, analyzing the effects of Darcy (Da) and Rayleigh (Ra) numbers on the thermal and fluid dynamic behavior within the system. Utilizing a combination of computational fluid dynamics (CFD) and the finite element method (FEM), the research focuses on steady-state, laminar flow conditions in two dimensions. The cavity, which is impermeable at its boundaries, contains a centrally located square region filled with a porous, isotropic material. The thermal environment is controlled with insulated horizontal walls and vertically positioned walls that experience sinusoidal temperature variations. The study examines how variations in the permeability of the porous medium (Da numbers ranging from 10−1 to 10−4) and the buoyancy-driven flow strength (Ra numbers spanning from 102 to 105) influence the velocity fields and heat transfer rates, with results expressed through Nusselt number (Nu) distributions. The findings reveal that higher Ra numbers, particularly at 105, significantly intensify convection within the cavity, thereby boosting local rates of heat transfer, especially in the central vertical section. The research identifies that optimal flow resistance in the porous medium occurs within the Da number range of 10−3 to 10−4. These insights are critical for advancing thermal management techniques, particularly in the natural cooling of electronic devices and improving insulation methods.","PeriodicalId":20597,"journal":{"name":"Processes","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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