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NURBS-based DEM for non-spherical particles

Particuology 2020年第2期18卷 65-76页

作者： Shiwen Liu Feiguo Chen Wei Ge Philippe Ricoux State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesP.O.Box 353Beijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Data Processing and Modeling TOTAL Scientific DivisionFrance

The discrete element method(DEM)is used to analyze complex practical granular systems;however,the representation of real shapes is an important consideration because behavior of non-spherical particles is unlike that of spherical particles both individually and *** this study,we use non-uniform rational basis-splines(NURBS)to describe the shapes of non-spherical particles and introduce a contact detection scheme based on quadratic convergence,to simulate the behaviors of elliptical *** simulation results are compared with those based on polygons,in terms of the shape description and contact treatment,to demonstrate the high accuracy and efficiency of NURBS-based DEM.

关键词： Non-spherical particle Discrete element method NURBS Facet-based DEM Granular system

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Whole-process Pollution control for Cost-Effective and Cleaner Chemical Production A Case Study of the Tungsten Industry in China

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engineering 2019年第4期5卷 768-776页

作者： Hongbin Cao He Zhao Di Zhang Chenming Liu Xiao Lin Yuping Li Pengge Ning Jiajun Sun Yi Zhang Zhi Sun Beijing Engineering Research Center of Process Pollution Control and National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Division of Environment Technology and EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

In this research,a methodology named whole-process pollution control(WPPC)is demonstrated that improves the effectiveness of process *** methodology considers waste/emission treatment as a step of the whole production process with respect to the minimization of cost and environmental impact for the whole *** following procedures are introduced in a WPPC process optimization:①a material and energy flow investigation and optimization based on a systematic understanding of the distribution and physiochemical properties of potential pollutants;②a process optimization to increase the utilization efficiency of different elements and minimize pollutant emissions;and③an evaluation to reveal the effectiveness of the optimization *** production of ammonium paratungstate was chosen for the case *** factors of the different optimization schemes-namely the cost-effectiveness factor and the environmental impact indicator-were evaluated and *** research demonstrates that by considering the nature of potential pollutants,technological innovations,economic viability,environmental impacts,and regulation requirements,WPPC can efficiently optimize a metal production process.

关键词： Whole-process pollution control process optimization Industrial pollution Tungsten

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Maximum-likelihood extremum seeking control of microalgae cultures

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IFAC-PapersOnLine 2021年第3期54卷 336-341页

作者： Laurent Dewasme Alain Vande Wouwer Christian Gabin Feudjio Letchindjio Afaq Ahmad Sebastian Engell Systems Estimation Control and Optimization (SECO) University of Mons (UMONS) Belgium Process Dynamics and Operations Group Department of Biochemical and Chemical Engineering TU Dortmund University Germany

This paper proposes a model-free extremum seeking control (ESC) approach to optimize the productivity of continuous cultures of microalgae, considering the dilution rate and the light intensity as manipulated variables, and the biomass concentration as single measurement. The resulting two-input single-output optimization problem is first solved using a recursive least-squares strategy based on the representation of the process by a Hammerstein block-oriented model. In order to face the presence of noise on the regressor variables (input and output signals), the problem is then reformulated as a maximum-likelihood estimation problem, which is solved on a moving horizon. Simulation results demonstrate the method performance.

关键词： real-time optimization optimal control parameter estimation least-squares biotechnology

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Distributed Online Convex Optimization with Adversarial Constraints: Reduced Cumulative Constraint Violation Bounds under Slater’s Condition

arXiv

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arXiv 2023年

作者： Yi, Xinlei Li, Xiuxian Yang, Tao Xie, Lihua Hong, Yiguang Chai, Tianyou Johansson, Karl H. Lab for Information & Decision Systems Massachusetts Institute of Technology CambridgeMA02139 United States Department of Control Science and Engineering College of Electronics and Information Engineering Tongji University Shanghai201804 China Shanghai Research Institute for Intelligent Autonomous Systems China The State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang110819 China School of Electrical and Electronic Engineering Nanyang Technological University 50 Nanyang Avenue Singapore639798 Singapore Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Sweden Digital Futures Stockholm10044 Sweden

This paper considers distributed online convex optimization with adversarial constraints. In this setting, a network of agents makes decisions at each round, and then only a portion of the loss function and a coordinate block of the constraint function are privately revealed to each agent. The loss and constraint functions are convex and can vary arbitrarily across rounds. The agents collaborate to minimize network regret and cumulative constraint violation. A novel distributed online algorithm is proposed and it achieves an O(T max{c,1−c}) network regret bound and an O(T 1−c/2) network cumulative constraint violation bound, where T is the number of rounds and c ∈ (0, 1) is a user-defined trade-off parameter. When Slater’s condition holds (i.e, there is a point that strictly satisfies the inequality constraints), the network cumulative constraint violation bound is reduced to O(T 1−c). Moreover, if the loss functions are strongly convex, then the network regret bound is reduced to O(log(T)), and the network cumulative constraint violation bound is reduced to O(√log(T)T) and O(log(T)) without and with Slater’s condition, respectively. To the best of our knowledge, this paper is the first to achieve reduced (network) cumulative constraint violation bounds for (distributed) online convex optimization with adversarial constraints under Slater’s condition. Finally, the theoretical results are verified through numerical simulations. Copyright © 2023, The Authors. All rights reserved.

关键词： Economic and social effects

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Characterization of Ralstonia Insidiosa C1 Isolated from Alpine Regions: Capability in Pha Degradation and Production

SSRN

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SSRN 2024年

作者： Chang, Young-Cheol Suzuki, Hinako Terayama, Takumi Reddy, M. Venkateswar Mawatari, Yasuteru Seki, Chigusa Sarkar, Omprakash Course of Chemical and Biological Engineering Division of Sustainable and Environmental Engineering Muroran Institute of Technology Hokkaido050-8585 Japan Department of Civil and Environmental Engineering Colorado State University Fort CollinsCO80523 United States Department of Sciences and Informatics Course of Chemical and Biological Systems Muroran Institute of Technology 27-1 Mizumoto Muroran050-8585 Japan Biochemical Process Engineering Division of Chemical Engineering Department of Civil Environmental and Natural Resources Engineering Luleå University of Technology Luleå971 87 Sweden

This study diverges by investigating the potential degradation of poly-3-hydroxybutyrate (PHB), a biodegradable plastic, in upstream locales such as alpine regions. PHB-degrading bacteria were identified in both campus soil, representing a residential area, and Kurodake soil, an alpine expanse in Hokkaido, Japan. Notably, campus soil exhibited greater microbial diversity. Conversely, Ralstonia insidiosa C1, isolated from Kurodake soil, demonstrated the highest PHB degradation proficiency. R. insidiosa C1 efficiently degraded up to 3% (w/v) of PHB and various films, including PBAT, P(3HB-co-3HV), and PHBH, at 14 ºC. This bacterium synthesized PHB using substrates such as 3-hydroxybutyric acid (3-HB), sugars, and acetic acid. Additionally, it produced P(3HB-co-3HV) using a mixture of fatty acids. Analysis verified that the biopolymer synthesized by strain C1 using glucose was PHB. The distinctive capability of R. insidiosa C1, encompassing both the production and degradation of bioplastics, underscores its potential to establish a novel material circulation model. © 2024, The Authors. All rights reserved.

关键词： Soils

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Monocular Visual SLAM based on VGG Feature Point Extraction 39

Monocular Visual SLAM based on VGG Feature Point Extraction

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39th Chinese control Conference, CCC 2020

作者： Dai, Xu-Yang Meng, Qing-Hao Zheng, Wen-Jian Zhu, Shao-Kai Tianjin University Institute of Robotics and Autonomous Systems Tianjin Key Laboratory of Process Measurement and Control School of Electrical and Information Engineering Tianjin300072 China

ISBN: (纸本)9789881563903

Significant progress has been made in the field of visual SLAM (Simultaneous Localization and Mapping). However, the localization accuracy of visual SLAM can be significantly reduced in low-texture and illumination-changing environments. To solve these problems, an enhanced visual SLAM algorithm based on VGG (Visual Geometry Group) network was proposed in this paper. Firstly, the VGG network for feature point extraction was incorporated into the visual odometry (VO) to achieve robust camera pose estimation. Secondly, an automatic corner annotation method was adopted to set up the training database, which could reduce the workload of data annotation. Thirdly, to make the backend optimization more suitable for the VGG based VO, the BA (bundle adjustment) optimization process was improved. Experimental results showed that, the proposed visual SLAM method outperformed the mainstream ORB-SLAM (Oriented FAST and Rotated BRIEF SLAM) method, in terms of the number of effective feature points, the robustness of feature matching process to light changes, and the accuracy of robot pose estimation. © 2020 Technical Committee on control Theory, Chinese Association of Automation.

关键词： Extraction

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Distributed Optimization by Network Flows with Spatio-Temporal Compression

arXiv

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arXiv 2024年

作者： Ren, Zihao Wang, Lei Yi, Xinlei Wang, Xi Yuan, Deming Yang, Tao Wu, Zhengguang Shi, Guodong State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and Control Zhejiang University Hangzhou310027 China College of Electronics and Information Engineering Tongji University China School of Electrical Engineering Telecommunications University of New South Wales Sydney Australia School of Automation Nanjing University of Science and Technology China State Key Laboratory of Synthetical Automation for Process Industries Northeastern University China Australian Centre for Robotics School of Aerospace Mechanical and Mechatronic Engineering The University of Sydney SydneyNSW2006 Australia

Several data compressors have been proposed in distributed optimization frameworks of network systems to reduce communication overhead in large-scale applications. In this paper, we demonstrate that effective information compression may occur over time or space during sequences of node communications in distributed algorithms, leading to the concept of spatio-temporal compressors. This abstraction classifies existing compressors as spatio-temporal compressors, with their effectiveness described by constructive stability criteria from nonlinear system theory. Subsequently, we apply these spatio-temporal compressors to standard continuous-time consensus flows and distributed prime-dual flows, establishing conditions ensuring convergence. Additionally, we introduce a novel observer-based distributed primal-dual continuous flow integrated with spatio-temporal compressors, which provides broader convergence conditions. These continuous flows achieve exponential convergence to the global optimum when the objective function is strongly convex and can be discretized using Euler approximations. Finally, numerical simulations illustrate the versatility of the proposed spatio-temporal compressors and verify the convergence of algorithms. Copyright © 2024, The Authors. All rights reserved.

关键词： Stability criteria

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Impact of polystyrene nanoplastics on primary sludge fermentation under acidic and alkaline conditions: Significance of antibiotic resistance genes

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Chemosphere 2024年 364卷 142777页

作者： Saila, Romana Zakaria, Basem S. Mirsoleimani Azizi, Seyed Mohammad Mostafa, Alsayed Dhar, Bipro Ranjan Department of Civil and Environmental Engineering University of Alberta EdmontonT6G 1H9 Canada Biological Systems and Engineering Division Lawrence Berkeley National Laboratory BerkeleyCA United States Advanced Biofuels and Bioproducts Process Development Unit EmeryvilleCA United States Stantec 10220 103 Ave NW #300 EdmontonABT5J 0K4 Canada

As a part of industrial or commercial discharge, the influx of nanoplastics (NPs) to the wastewater treatment plants is inevitable. Consequently, it has become a must to understand the effects of these NPs on different unit processes. This study aimed to investigate the impact of three different concentrations of polystyrene nanoplastics (PsNPs) on the fermentation of primary sludge (PrS), implemented in batch anaerobic bioreactors, at pH 5 and 10, considering the pH-dependent nature of the fermentation process. The results showed that PsNPs stimulated hydrogen gas production at a lower dose (50 μg/L), while a significant gas suppression was denoted at higher concentrations (150 μg/L, 250 μg/L). In both acidic and alkaline conditions, propionic and acetic acid predominated, respectively, followed by n-butyric acid. Under both acidic and alkaline conditions, exposure to PsNPs boosted the propagation of various antibiotic resistance genes (ARGs), including tetracycline, macrolide, β-lactam and sulfonamide resistance genes, and integrons. Notably, under alkaline condition, the abundance of sul2 gene in the 250 μg PsNPs/L batch exhibited a 2.4-fold decrease compared to the control batch. The response of the microbial community to PsNPs exposure exhibited variations at different pH values. Bacteroidetes prevailed at both pH conditions, with their relative abundance increasing after PsNPs exposure, indicating a positive impact of PsNPs on PrS solubilization. Adverse impacts, however, were detected in Firmicutes, Chloroflexi and Actinobacteria. The observed variations in the survival rates of various microbes stipulate that they do not have the same tolerance levels under different pH conditions. © 2024 Elsevier Ltd

关键词： Alkalinity

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Development of ACS Elements Training Complexes of the Power Equipment for the Increase of Its Reliability 2

Development of ACS Elements Training Complexes of the Power ...

引用

2nd International Youth Conference on Radio Electronics, Electrical and Power engineering, REEPE 2020

作者： Andryushin, A.V. Lunenko, V.S. Militonyan, S.M. National Research University 'MPEI' Department of automated process control systems National Research University 'MPEI' Department of heat power and heat engineering Volzhsky Russia

ISBN: (纸本)9781728156552

The article deals with the current issue of solving problems related to process control. An important role in solving these problems is played by the training process for students and employees of enterprises, which allows simulating the operation of real equipment. Volzhsky branch of Moscow Power Engeneering Institute (MPEI) developed simulators for studying the combination of alternative and renewable sources of electric and thermal energy and a training complex for means of control, automatic regulation and technological protection. The field equipment promotes to visually demonstrate functioning of existing equipment to students, including during laboratory work. The withdrawal of equipment to all modes is not possible for technological reasons and due to the random nature of weather conditions. The simulator of a geothermal heat pump was developed based on the mathematical models of the geothermal heat pump system elements. Comparison of the experimental and simulated values shows sufficient convergence, which indicates the correctness of the mathematical model and allows us to recommend it to practical application. © 2020 IEEE.

关键词： Simulators

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Recent advances in catalytic filters for integrated removal of dust and NOx from flue gas:fundamentals and applications

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Resources Chemicals and Materials 2022年第3期1卷 275-289页

作者： Changming Li Lin Huangfu Jianling Li Shiqiu Gao Guangwen Xu Jian Yu State Environmental Protection Key Laboratory of Food Chain Pollution Control School of Ecology and EnvironmentBeijing Technology and Business UniversityBeijing 100048China. State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization Pangang Group Research Institute Co.LtdPanzhihua 617000China State Key Laboratory of Multi-phase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China. School of Chemical Engineering Shenyang University of Chemical TechnologyShenyang 110142LiaoningChina

Catalytic filters including catalytic bag filters and catalytic filter candles, which couple the filters with denitrification catalysts to obtain the ability to simultaneously remove SOx, NOx and dust, have become the promising applied technology for the integrated flue gas treatment because of their huge advantages in reducing the initial investment, floor occupancy and maintenance cost. In this review, we will summarize the recent advances in the development of catalytic filters in terms of their process principles, filter material, denitrification catalysts, structure-function relationships and industrial applications. Moreover, suggestions about the current challenges and future opportunities are also given from the viewpoints of catalysts and filter material design, catalytic filter preparation methods, and their poisoning and regeneration, etc. With the further development of theory and engineering research, the extensive industrial application of catalytic filters in the field of multiple pollutants flue gas treatment is highly anticipated in the future.

关键词： Catalytic filter candles Catalytic bag filters Integrated flue gas treatment Industrial application

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