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fault Location Approach to Distribution Networks Based on Custom State Estimator

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Journal of Modern Power Systems and Clean Energy 2023年第6期11卷 1878-1889页

作者： Luis f.Ugarte Madson C.de Almeida Luís H.t.Bandória IEEE Department of Systems and Energy State University of CampinasSão Paulo 13083-970Brazil

this paper presents a properly designed branchcurrent based state estimator(BCBSE)used as the main core ofan accurate fault location approach(fLA)devoted to distribution *** to the approaches available in the literature,it uses only a limited set of conventional measurementsobtained from smart meters to accurately locate faults at busesor branches without requiring measurements provided by phasor measurement units(PMUs).this is possible due to themethods used to model the angular reference and the faultedbus,in addition to the proper choice of the weights in the stateestimator(SE).the proposed approach is based on a searchingprocedure composed of up to three stages:①the identificationof the faulted zones;②the identification of the bus closest tothe fault;and③the location of the fault itself,searching onbranches connected to the bus closest to the ***,this paper presents a comprehensive assessment of the proposedapproach,even considering the presence of distributed generation,and a sensitivity study on the proper weights required bythe SE for fault location purposes,which can not be found inthe *** show that the proposed BCBSE-basedfLA is robust,accurate,and aligned with the requirements ofthe traditional and active distribution networks.

关键词： Active distribution network branch current based state estimator fault location smart meter

Dynamics of the plane and solitary waves in a Noguchi network:Effects of the nonlinear quadratic dispersion

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Chinese Physics B 2020年第3期29卷 105-111页

作者： S A t fonkoua M S Ngounou G R Deffo f B Pelap S B Yamgoue A fomethe Unite de Recherche de Matiere Condensee d’Electronique et de traitement du Signal(UR-MACEtS) Faculte des SciencesUniversite de DschangBP 67 DschangCameroun Unite de Recherche de Mecanique et de Modelisation des Systemes Physiques(UR-2MSP) Faculte des SciencesUniversite de DschangBP 69 DschangCameroun Department of Physics Higher Teacher Training College BambiliUniversity of BamendaP.O.Box 39 BamendaCameroon

We consider a modified Noguchi network and study the impact of the nonlinear quadratic dispersion on the dynamics of modulated waves. In the semi-discrete limit, we show that the dynamics of these waves are governed by a nonlinear cubic Schrodinger equation. from the graphical analysis of the coefficients of this equation, it appears that the nonlinear quadratic dispersion counterbalances the effects of the linear dispersion in the frequency domain. Moreover, we establish that this nonlinear quadratic dispersion provokes the disappearance of some regions of modulational instability in the dispersion curve compared to the results earlier obtained by Pelap et al.(Phys. Rev. E 91 022925(2015)). We also find that the nonlinear quadratic dispersion limit considerably affects the nature, stability, and characteristics of the waves which propagate through the system. furthermore, the results of the numerical simulations performed on the exact equations describing the network are found to be in good agreement with the analytical predictions.

关键词： Noguchi network nonlinear quadratic dispersion modulational instability soliton

Distribution characteristics of polychlorinated biphenyls (PCBs) in coastal areas of Okinawa Island,Japan

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Chinese Journal of Oceanology and Limnology 2007年第3期25卷 247-253页

作者： M.A.SHEIKH f.NAKAMA t.OOMORI Marine and Environmental Science Graduate School of Engineering and Science University of the Ryukyus 1 Senbaru Nishihara-Town Okinawa 903-0213 Japan Detachment 3 Air Force Institute for Operational Health (AFIOH) Armstrong Laboratory Department of Chemistry Biology and Marine Science Faculty of Science University of the Ryukyus 1 Senbaru Nishihara-Town Okinawa 903-0213

Surface sediment and seawater samples were collected from coastal areas around Okinawa Island from September 2001 to May 2002. the samples were analyzed for total polychlorinated biphenyl (PCB) levels and homolog composition. the results show that total PCB levels ranged from 0.32 to 128.7 ng/g (dry wt.) in sediment and 1.59 to 2.48 ng/L in seawater. the levels exceed the Environmental Quality Standard (EQS) for water pollution of Japan. the distribution of PCB homolog showed different patterns in the sediments and seawaters. Penta-chlorobiphenyls (CBs) comprised the main congener group in seawater, while hexa-CBs were more abundant homologs in the sediments. the heavily contaminated sites featured higher CBs, including penta-CBs, hexa-CBs, and hepta-CBs, than those in less contaminated sites where tri-CBs dominated. this study provides current distribution and geochemical behavior of PCBs in the coastal areas around Okinawa Island.

关键词： PCBs Okinawa Island homolog coastal pollution

Designing metallic glasses with optimal combinations of glass-forming ability and mechanical properties

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Journal of Materials Science & technology 2021年第8期67卷 254-264页

作者： S.J.Wu Z.Q.Liu R.t.Qu Z.f.Zhang Laboratory of fatigue and fracture for Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

It is a long-standing challenge to search for metallic glasses(MGs)with optimal combinations of glassforming ability(GfA),strength and toughness in the vast compositional *** taking into account both recently developed ellipse criterion and temperature-based GfA criterion,here we established quantitative correlations among compositions,elastic constants,GfA and mechanical properties of MGs,which enable to predict the GfA,fracture strength and fracture surface simultaneously in advance once the compositions of MGs are *** data confirm the validity of this approach in ***,a strategy for designing MGs with optimal combinations of strength,toughness and GfA is proposed,which allows for high-throughput discovering glass formers with excellent mechanical properties.

关键词： Metallic glass Composition Elastic constant Mechanical property Glass-forming ability

Enhanced helium ion irradiation tolerance in a fe-Co-Ni-Cr-Al-ti high-entropy alloy with L12 nanoparticles

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Journal of Materials Science & technology 2023年第12期143卷 169-177页

作者： Y.L.Zhao f.L.Meng t.Yang J.H.Luan S.f.Liu G.M.Yeli W.t.Lin W.H.Liu X.J.Liu C.t.Liu J.J.Kai School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Materials Science and Engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina Department of Mechanical Engineering City University of Hong KongHong KongChina Institute of Nuclear&New Energy technology Tsinghua UniversityBeijing 100084China

L12-strengthened high entropy alloys(HEAs)with excellent room and high-temperature mechanical prop-erties have been proposed as promising candidates as structural materials for advanced nuclear ***,knowledge about their radiation response is fairly *** the present work,a novel HEA with a high density of L12 nanoparticles was irradiated with He ion at 500°*** electron microscope(tEM)and atom probe tomography(APt)were employed to study the evolution of mi-crostructural stability and radiation-induced *** to the single-phase feCoNiCr HEA,the main microstructural features were numerous large faulted dislocation loops and helium *** the irradiation resistance of the present L12-strengthened HEA is much improved in terms of reduced bubble size,which could be attributed to the considerable He trapping efficiency of the coherent pre-cipitate/matrix interface and the enhanced capability of the interface for damage elimination when the matrix channel width is *** analysis revealed that an inverse-Kirkendall-mechanism-dominated radiation-induced segregation(RIS)occurs around bubbles,where a significant Co enrichment and Ni de-pletion can be clearly *** addition,the competing dynamics of ballistic mixing and elemental clustering that raised from the irradiation-enhanced diffusion in a highly supersaturated matrix,along with the low precipitation nucleation barrier due to the small lattice misfit,lead to a dynamical pre-cipitation dissolution and re-precipitation appears under *** a promising phenomenon is expected to promote a potential self-healing effect and could in turn provide a sustainable irradiation tolerance over the operational lifetime of a reactor.

关键词： L12 nanoparticles High-entropy alloy Helium bubble Phase stability Radiation-induced segregation

Effect of water injection on the cavitation control:experiments on a NACA66(MOD)hydrofoil

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Acta Mechanica Sinica 2020年第5期36卷 999-1017,I0001页

作者： W.Wang t.tang Q.D.Zhang X.f.Wang Z.Y.An t.H.tong Z.J.Li School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of EducationDalian University of TechnologyDalian 116024China

the objective of this work is to investigate experimentally controlling cavitating flow over NACA66(MOD)hydrofoils by means of an active water injection along its suction *** continuous water vertically jets out of the chamber inside the hydrofoil through evenly distributed surface *** were carried out in cavitation water *** high-speed visualization technology and the particle image velocimetry(PIV)system to study the sheetlcloud cavity *** studied the effects of this active control on cavity evolution with four kinds of jet flow at two different jet *** analyzed the effect of water injection on the mechanism of the cavitating flow *** results were all compared with that for the original hydrofoil without jet and show that the active jet can effectively suppress the sheet/cloud cavitation characterized by shrinking the attached cavity size and breaking the large-scaled cloud sheding vortex cavity into small-scaled *** optimum effectiveness of cavitation suppression is affected by the jet flow rates and jet *** water injection at flow rate coefficient 0.0245 with the jet position of 0.45C reduces the maximum sheet cavity length by 79.4%and the cavity shedding is diminished completely,which gives the most superior effect of sheet cavitation *** jet blocks the re-entrant jet moving upstream and weakens the power of re-entrant jet and thus restrains the cavitation development effectively and stabilizes the flow field.

关键词： Cavitation active control Sheet/cloud cavitation.Water injection Re-entrant jet

Numerical and statistical approach for Casson-Maxwell nanofluid flow with Cattaneo-Christov theory

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Applied Mathematics and Mechanics(English Edition) 2021年第7期42卷 1063-1076页

作者： t.MUSHtAQ A.RAUf S.A.SHEHZAD f.MUStAfA M.HANIf Z.ABBAS Department of Mathematics COMSATS University IslamabadVehari CampusVehari 61100Pakistan Department of Mathematics COMSATS University IslamabadSahiwal CampusSahiwal 57000Pakistan Department of Mathematics The Islamia University of BahawalpurBahawalpur 63100Pakistan

the rheological features of an incompressible axi-symmetric Casson-Maxwell nanofluid flow between two stationary disks are *** lower permeable disk is located at z=-a,while the upper disk is placed at z=*** the disks are porous and subjected to uniform *** fluid properties such as thermal conductivity vary with *** Cattaneo-Christov thermal expression is implemented along with the Buongiorno nanofluid *** operating the similarity functions,the reduced form of the fluid model in terms of ordinary differential equations is obtained and solved by the bvp4 c numerical *** physical quantities are demonstrated graphically on the velocity and temperature ***-dimensional flow arrangements and twodimensional contour patterns against several dimensionless variables are also *** numerical values of the local Nusselt and Sherwood numbers for various quantities are presented in tabular *** intensity of the linear relationship between the Nusselt and Sherwood numbers is assessed through Pearson’s product-moment correlation *** statistical implication of the linear association between variables is also examined by the t-test statistic approach.

关键词： Casson-Maxwell fluid porous disk Buongiorno theory variable thermal conductivity Cattaneo-Christov model uniform injection

Comparison of artificial neural networks with empirical correlations for estimating the average cycle time in conical spouted beds

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Particuology 2019年第1期17卷 48-57页

作者： I. Estiatia M. tellabidea J.f. Saldarriaga H. Altzibara f.B. freirec J.t. freirec M. Olazara Department of Chemical Engineering University of the Basque CountryP.O. box 644E48080 BilbaoSpain Department of Civil and Environmental Engineering Universidad de los AndesCr.1 Este 19A-40BogotaColombia Department of Chemical Engineering Federal University of Sao CarlosRod. Washington Luis-km 235P.O. box 67613565-905Sao CarlosSPBrazil

Conventional spouted beds have been extensively used in many real-life applications but are not suited for all types of materials, especially fine particles, which require internal devices to improve their motion in the spouted bed. However, unlike conventional spouted beds, there are almost no mechanistic or empirical models available for the design of spouted beds with internals. Given the availability of an extensive but not experimentally designed database, the main purpose of this study is to present an analysis of neural networks and empirical models in terms of their suitability to fit and predict average cycle times in conical spouted beds with and without draft tubes. the parameters investigated are particle size, density, contactor angle, gas inlet diameter, static bed height, and draft tube features. Although the amount of information is always a key factor when fitting models, the size of the database used in this study strongly affects the fitting performance of empirical models, whereas artificial neural networks are more influenced by how the data are scaled. Results of model verification show that both techniques are suitable for predicting average cycle times for data outside the range covered by the database.

关键词： Empirical correlation Artificial neural network Average cycle time Conical spouted bed Draft tubes Modeling

Darcy-forchheimer flow of variable conductivity Jeffrey liquid with Cattaneo-Christov heat flux theory

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Applied Mathematics and Mechanics(English Edition) 2017年第4期38卷 557-566页

作者： M. A. MERAJ S.A. SHEHZAD t. HAYAt f.M. ABBASI A. ALSAEDI Department of Mathematics COMSATS Institute of Information TechnologySahiwal 57000Pakistan Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan NAAM Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Mathematics COMSATS Institute of Information TechnologyIslamabad 44000Pakistan

the role of the Cattaneo-Christov heat flux theory in the two-dimensional laminar flow of the Jeffrey liquid is discussed with a vertical sheet. the salient feature in the energy equation is accounted due to the implementation of the Cattaneo-Christov heat flux. A liquid with variable thermal conductivity is considered in the Darcy-forchheimer porous space. the mathematical expressions of momentum and energy are coupled due to the presence of mixed convection. A highly nonlinear coupled system of equations is tackled with the homotopic algorithm. the convergence of the homotopy expressions is calculated graphically and numerically. the solutions of the velocity and temperature are expressed for various values of the Deborah number, the ratio of the relaxation time to the retardation time, the porosity parameter, the mixed convective parameter, the Darcy-forchheimer parameter, and the conductivity parameter. the results show that the velocity and temperature are higher in fourier＇s law of heat conduction cases in comparison with the Cattaneo-Christov heat flux model.

关键词： Darcy-forchheimer porous medium variable conductivity Jeffrey liquid Cattaneo-Christov heat flux