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Flowing to the East-- Small Hydro in Developing Countries

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Small Hydro Power News 2006年第1期23卷 11-15页

作者： Simon Taylor Drona Upadhyay Maria Laguna engineering consultancy ITpower Project Man-ager at ESHA

While the growth of small hydro has slowed in Europe, things look very different in Asia. The region accounts for two-thirds of the world＇s hydro capacity, and far from slowing down, it is enjoying robust growth. Sim... 详细信息

关键词：发展中国家小水电可持续发展能源利用

Reconciliation of size-density bivariate distributions over a separating node

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Particuology 2008年第3期6卷 167-175页

作者： Bidarahalli Venkoba Rao Vivek Ganvir Sirigeri Jois Gopalakrishna Engineering and Industrial Services Tata Consultancy Services Limited 1Mangaldas RoadPune 411001India Tata Research Development and Design Centre Tata Consultancy Services Limited 54BHadapsar Industrial EstatePune 411013India Department of Mineral Processing Post Graduate CenterSandurKarnataka 583119India

Data reconciliation considers the restoration of mass balance among the noise prone measured data by way of component adjustments for the various particle size or particle density classes or assays over the separating node. In this paper, the method of Lagrange multipliers has been extended to balance bivariate feed and product size-density distributions of coal particles split from a settling column. The settling suspension in the column was split into two product fractions at 40% height from the bottom after a minute settling of homogenized suspension at start. Reconciliation of data assists to estimate solid flow split of particles to the settled stream as well as helps to calculate the profiles of partition curves of the marginal particle size or particle density distributions. In general, Lagrange multiplier method with uniform weighting of its components may not guarantee a smooth partition surface and thus the reconciled data needs further refinement to establish the nature of the surface. In order to overcome this difficulty, a simple alternative method of reconciling bivariate size-density data using partition surface concept is explored in this paper.

关键词： Data reconciliation Size-density partition surface Settling test

Use of incipient motion data for backward erosion piping models

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International Journal of Sediment Research 2019年第5期34卷 401-408页

作者： Vera M.van Beek Bryant A.Robbins Gijs J.C.M.Hoffmans Adam Bezuijen Leo C.van Rijn Deltares U.S.Army Engineer Research and Development Center Ghent University Leovanrijn-Sediment-consultancy

Backward erosion piping involves the gradual removal of granular material under the action of water flow from the foundation of a dam or levee, whereby shallow pipes are formed that grow in the direction opposite to the flow. This pipe-forming process can ultimately lead to failure of a water-retaining structure and is considered one of the most important failure mechanisms for dikes and levees in the Netherlands and the United States. Modeling of this mechanism requires the assessment of hydraulic conditions in the pipe, which are controlled by the particle equilibrium at the pipe wall. Since the pipe’s dimensions are controlled by the inflow to the pipe from the porous medium, the flow through the pipe is thought to be laminar for fine-to medium-grained sands. The literature provides data for incipient motion in laminar flow, which is reviewed here and complemented with data from backward erosion experiments. The experiments illustrate the applicability of the laminar incipient motion data to determine the erosion pipe dimensions and corresponding pipe hydraulics for fine-to medium-grained sands, for the purpose of backward erosion piping modeling.

关键词： Internal erosion Backward erosion piping Cylindrical test Incipient motion Dikes Levees

A DEM investigation on simple shear behavior of dense granular assemblies

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Journal of Central South University 2015年第12期22卷 4844-4855页

作者：史旦达薛剑峰赵振营史跻宇 School of Ocean Science and Engineering Shanghai Maritime University School of Engineering and Information Technology Federation University Australia Jiangsu Zhongshe Engineering consultancy Group

A micromechanical investigation on simple shear behavior of dense granular assemblies was carried out by discrete element *** series of numerical tests were performed to examine the effects of initial porosity,vertical stress and particle shape on simple shear behavior of the samples,*** was found that during simple shear the directions of principal stress and principal strain increment rotate differently with shear strain *** non-coaxiality between the two directions decreases with strain level and may greatly affect the shear behavior of the assemblies,especially their peak friction *** numerical modelling also reveals that the rotation of the principal direction of fabric anisotropy lags behind that of the major principal stress direction during simple shear,which is described as fabric hyteresis *** degrees of fabric and interparticle contact force anisotropies increase as particle angularity increases,whereas the orientations of these anisotropies have not been significantly influenced by particle *** extended stress–dilatancy relationship based on ROWE-DAVIS framework was proposed to consider the non-coaxiality effect under principal stress *** model was validated by present numerical results as well as some published physical test and numerical modelled data.

关键词： simple shear non-coaxiality fabric anisotropy shear strength discrete element method

Practical numerical simulation of the effect of TBM process pressures on soil displacements through 3D shift iteration

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Underground Space 2018年第4期3卷 297-309页

作者： Benno Ring Marc Comulada Ring–consultancy in Tunnelling Alpenstr.582131 StockdorfGermany Maidl Tunnelconsultants Goethestr.7480336 MunichGermany

A 3D-finite element model is illustrated that allows for the iterative simulation of the shield drive with its face and grouting pressures by shifting the determined stresses and displacements after each calculation *** are performed for the tunneling of Rio de Janeiro’s Line 4 and compared to the results of analytical limit equilibrium analyses and monitoring results of the actual TBM-drive.

关键词： Settlements TBM pressures 3D-Finite element method Numerical simulation Shift iteration

Advanced Synthesis Techniques for Microwave Filters

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ZTE Communications 2011年第2期9卷 27-35页

作者： Richard J Cameron Canopus consultancy

With the advent of the ‘digital revolution’ that has made possible services such as the world wide web, satellite broadcasting and mobile and trunk telephony, the finite RF spectrum allocated for terrestrial and satellite telecommunication systems is becoming increasingly crowded. This has impacted significantly upon the performance required from the microwave equipment that comprises these systems. In the case of microwave filters, greater in-band linearity to avoid signal distortion and out-of-band isolation to suppress interference are routinely specified, which can only be satisfied by advanced filtering characteristics. This article presents the coupling matrix approach to the synthesis of prototype filter networks, enabling the realization of the hardware embodying the enhanced performance needed by today’s high capacity systems.

关键词： filter network synthesis coupling matrix microwave filters

A Global Britain?--Brexit:a clumsy English attempt to have their cake and eat it too

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Beijing Review 2020年第45期63卷 26-27页

作者： Adriel Kasonta AK consultancy

Since the British voted to leave the EU in the summer of 2016,it was clear that something that seemed to be simple in theory was to be difficult in *** suffering several parliamentary defeats during her time at 10 Downing Street,Theresa May’s exit deal attempts received a fi nal blow when she was ultimately forced to leave offi ce in disgrace last year.

关键词： Britain something leave

Rheological Behavior of Basalt Fiber Reinforced Asphalt Mastic

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Journal of Wuhan University of Technology(Materials Science) 2014年第5期29卷 950-955页

作者：顾兴宇 XU Tingting NI Fujian Transportation College Southeast University Road Maintenance Technology Engineering Center of Jiangsu Province Jiangsu Zhongshe Engineering consultancy Group Co. LTD

The characters of basalt fiber are analyzed and compared with commonly used fibers. The rheological behaviors of the basalt fiber reinforced asphalt mastic are investigated by the dynamic shear rheological tests and the repeated creep tests. The results show that basalt fiber has excellent reinforced performances, such as high asphalt absorption ratio, low water absorption ratio, high tensile strength, high elastic modulus and high temperature stability. The rutting factor of the fiber reinforced asphalt mastic is higher than the plain asphalt mastic and the reinforced effects are more remarkable under high temperature. The rheological performances of the asphalt mastic demonstrate a good linear relationship between different temperature and loading frequency. The creep stiffness modulus of the asphalt mastic at different loading time can be expressed by power function. Improved Burgers model is used to represent the rheological behaviors of the asphalt mastic with basalt fiber and the model parameters are estimated.

关键词： basalt fiber asphalt mastic dynamic shear rheological test repeated creep test rheological model

LAYERED ARCHITECTURE FOR ASSEMBLING BUSINESS APPLICATIONS FROM DISTRIBUTED COMPONENTS

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Systems Science and Systems Engineering 2004年第1期13卷 60-77页

作者： Hemant JAIN Balarama REDDY School of Business Administration University of Wisconsin-MilwaukeeMilwaukeeWI 53201 Tata Consultancy ServicesSchool of Business Administration University of Wisconsin-MilwaukeeMilwaukeeWI 53201 Tata Consultancy Services

Modern business applications are generally characterized as: distributed across many processors and/or sites, access data from multiple sources and have web-based interfaces. These applications may also involve systems or processes from multiple companies or vendor provided services. The changing business environment and technologies requires that the application be agile and adoptable in short period. Component based development has recently attracted increased attention as a preferred technology for developing business applications. However, the tools and techniques for the design, implementation, management and deployment of applications based on these technologies are at a very early stage of development. This paper presents an overview of a distributed architecture for the deployment of applications based on business components. The application of the architecture in an auto insurance claim domain is briefly described. A number of open research issues have been identified.

关键词： Business component object oriented system software development CBSD EAI