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A global perspective on microbial risk factors in effluents of wastewater treatment plants

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Journal of Environmental Sciences 2024年第4期138卷 227-235页

作者： Kejing Chen Jinsong Liang Yuhan Wang Yechen Tao Yun Lu Aijie Wang school of Civil and Environmental engineering Harbin Institute of TechnologyShenzhen 518055China Shenzhen Guohuan Environmental Protection Technology Development Co. LTD.Shenzhen 518055China State Key Joint Laboratory of Environmental Simulation and Pollution Control State Environmental Protection Key Laboratory of Microorganism Application and Risk ControlSchool of EnvironmentTsinghua UniversityBeijing 100084China

Effective monitoring and management of microbial risk factors in wastewater treatment plants(WWTPs)effluents require a comprehensive investigation of these risks.A global survey on microbial risk factors in WWTP effluents could reveal important insights into their risk *** study aims to explore the abundance and types of antibiotic resistance genes(ARGs),virulence factor genes(VFGs),the vector of ARG/VFG,and dominant pathogens in global WWTP *** collected 113 metagenomes of WWTP effluents from the Sequence Read Archive of the National Center for Biotechnology Information and characterized the microbial risk *** results showed that multidrug resistance was the dominant ARG type,while offensive virulence factors were the most abundant type of *** most dominant types of ARGs in the vector of plasmid and phage were both aminoglycoside resistance,which is concerning as aminoglycosides are often a last resort for treating multi-resistant *** baumannii was the most dominant pathogen,rather than Escherichia coli,and a weak negative correlation between Escherichia coli and two other dominant pathogens(Acinetobacter baumannii and Bacteroides uniformis)suggests that using Escherichia coli as a biological indicator for all pathogens in WWTP effluents may not be *** Getah virus was the most dominant virus found in global WWTP *** study presents a comprehensive global-scale investigation of microbial risk factors in WWTP effluents,providing valuable insights into the potential risks associated with WWTP effluents and contributing to the monitoring and control of these risks.

关键词： Wastewater treatment plant Microbial risk factor Effluent Pathogen Antibiotic resistance gene Virulence factor gene

Combined use of fly ash and silica to prevent the long-term strength retrogression of oil well cement set and cured at HPHT conditions

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Petroleum Science 2024年第2期21卷 1122-1134页

作者： Guo-Dong Cheng Xue-Yu Pang Jin-Sheng Sun Zheng-Song Qiu Chuang-Chuang Wang Jian-Kun Qin Ning Li school of Petroleum engineering China University of Petroleum(East China)Qingdao266580ShandongChina National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Oil and Gas engineering Research Institute(Tarim Oilfield Company) China National Petroleum CorporationTarim841000XinjiangChina

The long-term strength retrogression of silica-enriched oil well cement poses a significant threat to wellbore integrity in deep and ultra-deep wells, which is a major obstacle for deep petroleum and geothermal energy development. Previous attempts to address this problem has been unsatisfactory because they can only reduce the strength decline rate. This study presents a new solution to this problem by incorporating fly ash to the traditional silica-cement systems. The influences of fly ash and silica on the strength retrogression behavior of oil well cement systems directly set and cured under the condition of 200°C and 50 MPa are investigated. Test results indicate that the slurries containing only silica or fly ash experience severe strength retrogression from 2 to 30 d curing, while the slurries containing both fly ash and silica experience strength enhancement from 2 to 90 d. The strength test results are corroborated by further evidences from permeability tests as well as microstructure analysis of set cement. Composition of set cement evaluated by quantitative X-ray diffraction analyses with partial or no known crystal structure(PONKCS) method and thermogravimetry analyses revealed that the conversion of amorphous C-(A)-S-H to crystalline phases is the primary cause of long-term strength *** addition of fly ash can reduce the initial amount of C-(A)-S-H in the set cement, and its combined use with silica can prevent the crystallization of C-(A)-S-H, which is believed to be the working mechanism of this new admixture in improving long-term strength stability of oil well cement systems.

关键词： Fly ash Long-term strength retrogression High temperature Quantitative X-ray diffraction(QXRD) Partial or no known crystal structure(PONKCS)

Comparative analysis of thermodynamic and mechanical responses between underground hydrogen storage and compressed air energy storage in lined rock caverns

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International Journal of Mining Science and Technology 2024年第4期34卷 531-543页

作者： Bowen Hu Liyuan Yu Xianzhen Mi Fei Xu Shuchen Li Wei Li Chao Wei Tao Zhang State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground engineering China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Large Structure Health Monitoring and Control Shijiazhuang Tiedao UniversityShijiazhuang 050043China school of Mechanics and Civil engineering China University of Mining and TechnologyXuzhou 221116China

Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar ***,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage *** study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock *** thermodynamic responses are validated using additional simulations and the field test *** and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation *** reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and *** steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing *** CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same *** present research can provide references for the selection of energy storage methods.

关键词： Underground hydrogen storage Compressed air energy storage Mechanical response Thermodynamic response Lined rock caverns

Saddlepoint Approximation Method in Reliability Analysis:A Review

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Computer Modeling in engineering & Sciences 2024年第6期139卷 2329-2359页

作者： Debiao Meng Yipeng Guo Yihe Xu Shiyuan Yang Yongqiang Guo Lidong Pan Xinkai Guo school ofMechanical and Electrical engineering University of Electronic Science and Technology of ChinaChengdu611731China Institute of Electronic and Information engineering of UESTC in Guangdong Dongguan523808China Glasgow College University of Electronic Science and Technology of ChinaChengdu611731China Beijing Research Institute of Mechanical&Electrical Technology Ltd.Beijing100083China

The escalating need for reliability analysis(RA)and reliability-based design optimization(RBDO)within engineering challenges has prompted the advancement of saddlepoint approximationmethods(SAM)tailored for such *** article offers a detailed overview of the general SAM and summarizes the method characteristics ***,recent enhancements in the SAM theoretical framework are ***,the mean value first-order saddlepoint approximation(MVFOSA)bears resemblance to the conceptual framework of the mean value second-order saddlepoint approximation(MVSOSA);the latter serves as an auxiliary approach to the *** distinction is rooted in the varying expansion orders of the performance function as implemented through the Taylor *** the saddlepoint approximation and third-moment(SATM)and saddlepoint approximation and fourth-moment(SAFM)strategies model the cumulant generating function(CGF)by leveraging the initial random moments of the *** their optimal application domains diverge,each method consistently ensures superior relative precision,enhanced efficiency,and sustained *** method elucidated is exemplified through pertinent RA or RBDO *** juxtaposing them against alternative strategies,the efficacy of these methods becomes *** outcomes proffered are subsequently employed as a foundation for contemplating prospective theoretical and practical research endeavors concerning *** main purpose and value of this article is to review the SAM and reliability-related issues,which can provide some reference and inspiration for future research scholars in this field.

关键词： Reliability analysis reliability-based design optimization saddlepoint approximation

An Improved JSO and Its Application in Spreader Optimization of Large Span Corridor Bridge

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Computer Modeling in engineering & Sciences 2024年第3期138卷 2357-2382页

作者： Shude Fu Xinye Wu Wenjie Wang Yixin Hu Zhengke Li Feng Jiang Fujian Key Laboratory of Digital Simulations for Coastal Civil engineering School of Architecture and Civil EngineeringXiamen UniversityXiamen361005China Xiamen Transportation Infrastructure Intelligent Management and Maintenance engineering Technology Research Center Xiamen361005China Fuzhou Company of China Communications Construction Co. Ltd.Fuzhou350005China

In this paper,given the shortcomings of jellyfish search algorithmwith low search ability in the early stage and easy to fall into local optimal solution,this paper introduces adaptive weight function and elite strategy,improving the global search scope in the early stage and the ability to refine the local development in the later *** the numerical study,the benchmark problem of dimensional optimization with a 10-bar truss structure and simultaneous dimensional shape optimization with a 15-bar truss structure is adopted,and the corresponding penalty method is used for constraint *** test results show that the improved jellyfish search algorithm can provide better truss sections as well as *** when the steel main truss of the large-span covered bridge is lifted,the site is limited and the large lifting equipment cannot enter the site,and the original structure does not meet the problem of stress concentration and large deformation of the bolt group,so the spreader is used to lift,and the improved jellyfish search algorithm is introduced into the design optimization of the *** results show that the improved jellyfish algorithm can efficiently and accurately find out the optimal shape and weight of the spreader,and throughMidas Civil simulation,the spreader used canmeet the requirements of weight and safety.

关键词： Truss optimization improved JSO size optimization shape optimization

Desired Dynamic Equation for Primary Frequency Modulation Control of Gas Turbines

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Energy engineering 2024年第5期121卷 1347-1361页

作者： Aimin Gao Xiaobo Cui Guoqiang Yu Jianjun Shu Tianhai Zhang Thermal Power Center Jiangsu Frontier Electric Technology Co.Ltd.Nanjing211102China school of Energy and Power engineering Nanjing Institute of TechnologyNanjing211167China

Gas turbines play core roles in clean energy supply and the construction of comprehensive energy *** control performance of primary frequency modulation of gas turbines has a great impact on the frequency control of the power ***,there are some control difficulties in the primary frequency modulation control of gas turbines,such as the coupling effect of the fuel control loop and speed control loop,slow tracking speed,and so *** relieve the abovementioned difficulties,a control strategy based on the desired dynamic equation proportional integral(DDE-PI)is proposed in this *** on the parameter stability region,a parameter tuning procedure is *** is carried out to address the ease of use and simplicity of the proposed tuning ***,DDE-PI is applied to the primary frequency modulation system of an MS6001B heavy-duty gas *** simulation results indicate that the gas turbine with the proposed strategy can obtain the best control performance with a strong ability to deal with system *** proposed method shows good engineering application potential.

关键词： Gas turbine primary frequency modulation(PFM) desired dynamic equation(DDE) proportion-integral(PI)

Development of a Three-Dimensional Multiscale Octree SBFEM for Viscoelastic Problems of Heterogeneous Materials

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Computer Modeling in engineering & Sciences 2024年第8期140卷 1831-1861页

作者： Xu Xu Xiaoteng Wang Haitian Yang Zhenjun Yang Yiqian He State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDepartment of Engineering MechanicsDalian University of TechnologyDalian116024China Hubei Key Laboratory of Geotechnical and Structural Safety School of Civil EngineeringWuhan UniversityWuhan430072China Mechanik–Materialtheorie Ruhr-Universität BochumBochum44801Germany

The multiscale method provides an effective approach for the numerical analysis of heterogeneous viscoelastic materials by reducing the degree of freedoms(DOFs).A basic framework of the Multiscale Scaled Boundary Finite Element Method(MsSBFEM)was presented in our previous works,but those works only addressed two-dimensional *** order to solve more realistic problems,a three-dimensional MsSBFEM is further developed in this *** the proposed method,the octree SBFEM is used to deal with the three-dimensional calculation for numerical base functions to bridge small and large scales,the three-dimensional image-based analysis can be conveniently conducted in small-scale and coarse nodes can be flexibly adjusted to improve the computational ***,the Temporally Piecewise Adaptive Algorithm(TPAA)is used to maintain the computational accuracy of multiscale analysis by adaptive calculation in time *** results of numerical examples show that the proposed method can significantly reduce the DOFs for three-dimensional viscoelastic analysis with good *** instance,the DOFs can be reduced by 9021 times compared with Direct Numerical Simulation(DNS)with an average error of 1.87%in the third example,and it is very effective in dealing with three-dimensional complex microstructures directly based on images without any geometric modelling process.

关键词： Three-dimensionalmultiscale viscoelastic analysis numerical base functions octree SBFEM image-based analysis temporally piecewise adaptive algorithm

Numerical analysis on the transport properties and residence time distribution of ribbon biomass particles in a riser reactor based on CFD-DEM approach

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Particuology 2024年第4期87卷 133-146页

作者： Haichao Zhao Conghui Gu Bingyang Xu Yuan Liu Mingpu Du Kaiyuan Deng Jingyu Zhu Iana Voronina Zhulin Yuan school of Energy and Power Jiangsu University of Science and TechnologyZhenjiang212100China China Tobacco Jiangxi Industrial Co.Ltd. Nanchang330096China Institute of Mechanics and Power engineering Ogarev Mordovia State UniversitySaransk430005Russia Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing210096China

A bended ribbon biomass particle model was developed to explore the dynamic transport properties inside a riser *** time distribution(RTD)of the particles was analyzed by using the Eulerian-Lagrange *** effects of sampling height,particle density,particle size and gas-to-solid mass ratio on RTD were *** coupled Computational Fluid Dynamics and Discrete Element Method(CFD-DEM)model was verified firstly by experimental data on pressure drop and residence time distribution density *** simulation results demonstrated that the ribbon biomass particles display a typical annular-core spatial distribution during *** RTD of particles exhibit an approximate single-peaked normal *** mean residence time(MRT)can reach up to 0.7 s when the particle density is 1200 kg/m^(3).Particle with higher density has longer mean residence *** flow patterns are closer to plug flow if particle length over 12 *** particle flow pattern is not sensitive to changes in particle density and size,while the gas-to-material mass ratio has a significant impact on it.

关键词： Riser Gas-solids two-phase flow Ribbon biomass particles Residence time distribution CFD-DEM

Computing large deviation prefactors of stochastic dynamical systems based on machine learning

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Chinese Physics B 2024年第4期33卷 364-373页

作者：李扬袁胜兰陆凌宏志刘先斌 school of Automation Nanjing University of Science and TechnologyNanjing 210094China Department of Mathematics School of SciencesGreat Bay UniversityDongguan 523000China Center for Mathematical Sciences Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Mechanics and Control for Aerospace Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

We present a large deviation theory that characterizes the exponential estimate for rare events in stochastic dynamical systems in the limit of weak *** aim to consider a next-to-leading-order approximation for more accurate calculation of the mean exit time by computing large deviation prefactors with the aid of machine *** specifically,we design a neural network framework to compute quasipotential,most probable paths and prefactors based on the orthogonal decomposition of a vector *** corroborate the higher effectiveness and accuracy of our algorithm with two toy *** experiments demonstrate its powerful functionality in exploring the internal mechanism of rare events triggered by weak random fluctuations.

关键词： machine learning large deviation prefactors stochastic dynamical systems rare events