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Using meshes to change the characteristics of simulated rainfall produced by spray nozzles

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International Soil and Water Conservation Research 2014年第2期2卷 67-78页

作者： Sílvia C.P.Carvalho João L.M.P.de Lima M.Isabel P.de Lima Department of Civil Engineering Faculty of Science and TechnologyUniversity of CoimbraCoimbraPortugal Department of Civil Engineering Campus II-University of CoimbraRua Luís Reis Santos3030-788 CoimbraPortugal

Rainfall simulators have been used for many years contributing to the understanding of soil and water conservation ***,rainfall simulators’design and operation might be rather demanding for achieving specific rainfall intensity distributions and drop characteristics and are still open for *** study explores the potential of combining spray nozzle simulators with meshes to change rainfall characteristics,namely drop properties(drop diameters and fall speeds).A rainfall simulator laboratory set-up was prepared that enabled the incorporation of different wire meshes beneath the spray *** tests conducted in this exploratory work included different types of spray nozzles,mesh materials(plastic and steel),square apertures and wire thicknesses,and positions of the meshes in relation to the *** intensity and drop size distribution and fall speed were *** showed that the meshes combined with nozzles increased the mean rainfall intensity on the 1 m^(2) control plot below the nozzle and altered the rain drops’properties,by increasing the mass-weighted mean drop diameter,for example.

关键词： Rainfall simulators Spray nozzle meshes Drop characteristics

Finite Element meshes Auto-Generation for the Welted Bifurcation

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Computer Aided Drafting,Design and Manufacturing 2004年第2期14卷 1-7页

作者： YUANMei LIYa-ping SchoolofMechanicalEngineering WuhanInstituteofTechnologyWuhan430073China SchoolofMechanicalEngineering WuhanUniversityWuhan430073China

In this paper, firstly, a mathematical model for a specific kind of welted bifurcation is established, the parametric equation for the intersecting curve is resulted in. Secondly, a method for partitioning finite element meshes of the welted bifurcation is put forward, its main idea is that developing the main pipe surface and the branch pipe surface respectively, dividing meshes on each developing plane and obtaining meshes points, then transforming their plane coordinates into space coordinates. Finally, an applied program for finite element meshes auto-generation is simply introduced, which adopt ObjectARX technique and its running result can be shown in AutoCAD. The meshes generated in AutoCAD can be exported conveniently to most of finite element analysis soft wares, and the finite element computing result can satisfy the engineering precision requirement.

关键词： finite element meshes ObjectARX bifurcation

A predictor-corrector scheme for solving nonlinear fractional differential equations with uniform and nonuniform meshes

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International Journal of Modeling, Simulation, and Scientific Computing 2019年第5期10卷 108-142页

作者： Mohammad Javidi Mahdi Saedshoar Heris Bashir Ahmad Faculty of Mathematical Sciences University of Tabriz TabrizIran Nonlinear Analysis and Applied Mathematics Research Group(NAAM)King Abdulaziz University P.O.Box 80203 Jeddah 21589Saudi Arabia

In this paper,we develop two algorithms for solving linear and nonlinear fractional differential equations involving Caputo *** designing new predictor–corrector(PC)schemes,we select the mesh points based on the two equal-height and equal-area ***,the error bounds of PC schemes with uniform and equidistributing meshes are ***,examples are constructed for illustrating the obtained PC schemes with uniform and equidistributing meshes.A comparative study is also presented.

关键词： meshes fractional uniform

Dynamic Mechanical Properties of Tissue after Long-Term Implantation of Collagen and Polypropylene meshes in Animal Models

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Open Journal of Urology 2013年第3期3卷 155-159页

作者： Michail G. Christodoulou Apostolos Papalois Dionysios Mouzakis Stefanos Zaoutsos Theodoros Kouranos Miltiadis Seferlis Charilaos Katsifotis Angelos Liapis 2nd Department of Obstetrics and Gynecology Aretaieio Hospital University of Athens Athens Greece Department of Mechanical Engineering Technological Educational Institute of Larissa Larissa Greece Department of Urology General Hospital of Athens Polycliniki Athens Greece Experimental Research Center ELPEN Athens Greece

Purpose: Pelvic floor reconstructive surgery has grown significantly in recent years. A wide variety of available types of meshes exist but the safety and success has not been adequately proven. We sought to evaluate the effects on dynamic biomechanical properties of tissue after long-term implantation of synthetic and biological grafts. Methods: A total of 96 New Zealand white female rabbits (approximately 3 kg) were used, 72 of which were surgically implanted with acellular, collagen mesh (n = 36) or nonabsorbable monofilament polypropylene mesh (n = 36). There was a no mesh-rupture of fascia group (n = 12) and a second, no-mesh, no-fascia rupture control group (n = 12). In the 59 rabbits, of 72 (13 died) tissue was harvested 3 months (n = 24), 6 months (n = 23) and 9 months (n = 12) later, while in the fascia rupture group, tissue was harvested 6 months later. Tissue samples (2 × 2 cm) underwent dynamic mechanical analysis (DMA) testing during which the dynamic rigidity and tissue damping capacities were measured. The statistical analysis was performed with General Linear Model with Tukeys post hoc testing (sPss v.17.0). Results: With respect to mesh type, the rabbit tissue in which polypropylene mesh was used showed the greatest dynamic rigidity. Those with biological mesh delivered the lowest rigidity results, while the two other groups had almost similar behavior. The meshes exhibited their highest relative dynamic tissue stiffening effect at 9 months. Conclusions: Biological mesh causes lower tissue rigidity, resulting in inferior mechanical response and thus seems to be inferior to polypropylene.

关键词： Biomechanical Properties Tissue Stiffening Collagen-Polypropylene meshes

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Preface

Science China(Technological Sciences) 2024年第4期67卷 965-965页

作者： LI Xu School of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China

The numerical manifold method(NMM)is a numerical method pioneered by Genhua Shi in 1991 to approximate continuousdiscontinuous(C-D)fields.C-D fields are widespread and involve complex boundaries,moving discontinuities,geometrical uncertainties,*** the C-D problems can be quite challenging to the classic finite element method(FEM)using conforming *** and updating the meshes to conform to the complex boundaries,moving discontinuities。

关键词： meshes manifold moving

A High-order Coupled Compact Integrated RBF Approximation Based Domain Decomposition Algorithm for Second-order Differential Problems

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Computer Modeling in Engineering & Sciences 2015年第4期104卷 251-304页

作者： C.M.T.Tien N.Pham-Sy N.Mai-Duy C.-D.Tran T.Tran-Cong Computational Engineering and Science Research Centre Faculty of HealthEngineering and SciencesThe University of Southern QueenslandToowoombaQueensland 4350Australia

This paper presents a high-order coupled compact integrated RBF(CC IRBF)approximation based domain decomposition(DD)algorithm for the discretisation of second-order differential *** Schwarz DD algorithms,including one-level additive/multiplicative and two-level additive/multiplicative/hybrid,are *** CCIRBF based DD algorithms are analysed with different mesh sizes,numbers of subdomains and overlap sizes for Poisson *** convergence analysis shows that the CCIRBF two-level multiplicative version is the most effective algorithm among various schemes employed ***,the present CCIRBF two-level method converges quite rapidly even when the domain is divided into many subdomains,which shows great promise for either serial or parallel *** practical tests,we then incorporate the CCIRBF into serial and parallel two-level multiplicative *** numerical examples,including those governed by Poisson and Navier-Stokes equations are analysed to demonstrate the accuracy and efficiency of the serial and parallel algorithms implemented with the *** results show:(i)the CCIRBF-Serial and-Parallel algorithms have the capability to reach almost the same solution accuracy level of the CCIRBF-Single domain,which is ideal in terms of computational calculations;(ii)the CCIRBF-Serial and-Parallel algorithms are highly accurate in comparison with standard finite difference,compact finite difference and some other schemes;(iii)the proposed CCIRBF-Serial and-Parallel algorithms may be used as alternatives to solve large-size problems which the CCIRBF-Single domain may not be able to deal *** ability of producing stable and highly accurate results of the proposed serial and parallel schemes is believed to be the contribution of the coarse mesh of the two-level domain decomposition and the CCIRBF *** is noted that the focus of this paper is on the derivation of highly accurate serial and parallel algorithms

关键词： Coupled compact integrated RBF (CCIRBF) Schwarz domain decomposition one-level two-level coarse meshes additive multiplicative hybrid serial parallel colouring technique Poisson equation Naiver-Stokes equation liddriven cavity

Further results on ultraconvergence derivative recovery for odd-order rectangular finite elements

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Science China Mathematics 2009年第8期52卷 1671-1684页

作者： WEI JiDong ZHU QiDing College of Mathematics and Computer Science Hunan Normal UniversityChangsha 410081China Department of Mathematics Hengyang Normal UniversityHengyang 421000China

For rectangular finite element, we give a superconvergence method by SPR technique based on the generalization of a new ultraconvergence record and the sharp Green function estimates, by which we prove that the derivative has ultra-convergence of order O(hk+3) (k 3 being odd) and displacement has order of O(hk+4) (k 4 being even) at the locally symmetry points.

关键词： finite element ultra-convergence locally symmetric meshes SPR operator

High order finite volume methods for singular perturbation problems

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Science China Mathematics 2008年第8期51卷 1391-1400页

作者： CHEN ZhongYing HE ChongNan WU Bin Department of Scientific Computing and Computer Applications Sun Yat-Sen UniversityGuangzhou 510275China College of Mathematics and Computer Science Guangxi University for NationalitiesNanning 530006China

In this paper we establish a high order finite volume method for the fourth order singular perturbation *** conjunction with the optimal meshes,the numerical solutions resulting from the method have optimal convergenc... 详细信息

关键词： finite volume methods optimal meshes singular perturbation problems

ON THE DEEP SEA DEMERSAL FISH COMMUNITIES OF THE EAST CHINA SEA

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Chinese Journal of Oceanology and Limnology 1989年第2期7卷 157-168页

作者：沈金鳌程炎宏 Shanghai Fisheries University East China Sea Fisheries Research Institute

Cluster analysis of data on the species similarity index offish samples taken at various sampling stations of different depths by the R /V " Dongfang " of the East China Sea Fisheries Research Institute, Chinese Academy of Fisheries Science, during the deep sea demersal fish resources survey in May - November, 1981, showed deep sea demersal fish fauna of the western part of the East China Sea can be grouped into the following communities :1)The outer continental shelf community ,2)The continental slope community, and3)The western Okinawa Trough community .The authors found that not only the species diversity index, but also the species similarity index are important criteria to reflect the structure of biotic community.

关键词： similarity continental triangular fauna shelf outer EAST depths meshes biotic