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Sample records for volume methods foundation

  1. Condition Assessment Survey (CAS) Program. Deficiency standards and inspections methods manual: Volume 1, 0.01 Foundations and footings

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    General information is presented for asset determinant factor/CAS repair codes/CAS cost factors; guide sheet tool & material listing; testing methods; inspection frequency; standard system design life tables; system work breakdown structure; and general system/material data. Deficiency standards and inspection methods are given for footings - spread/strip/grade beams; foundation walls; foundation dampproofing/waterproofing; excavation/backfill/ and piles & caissons.

  2. Physical foundations and experience of application of method of determination of volumes of all group of pore channels in powders and porous bodies

    International Nuclear Information System (INIS)

    Gabelkov, S.V.

    2011-01-01

    Physical foundations of the method of determination of the relative volumes of each group of pore channels that are available in a porous body on removal of work liquid from them at its evaporation were developed. Advantages and disadvantages are given, experience using of this method is extended at creating of ceramic matrix (cubic zirconia and magnesium-aluminium spinel) for isolation of high active waste. This method in combination with method of electronic microscopy has given an ability to investigate destruction of agglomerates and aggregates of xerogels and powders at milling and pressing, agglomeration of powders at its production and evolution of each component of pore spaces at sintering of porous bodies.

  3. Foundation, and also method for its production

    NARCIS (Netherlands)

    Katsma, H.

    2001-01-01

    Foundation, and method for the production of such a foundation. It is proposed that it be based on prefabricated concrete elements. The elements consist of base elements (2) and end elements (4). Each element is provided with two sockets for receiving pretensioning cables (6), which sockets are

  4. Information architecture. Volume 1, The foundations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    The Information Management Planning and Architecture Coordinating Team was formed to establish an information architecture framework to meet DOE`s current and future information needs. This department- wide activity was initiated in accordance with the DOE Information Management Strategic Plan; it also supports the Departmental Strategic Plan. It recognizes recent changes in emphasis as reflected in OMB Circular A-130 and the Information Resources Management Planning Process Improvement Team recommendations. Sections of this document provides the foundation for establishing DOE`s Information Architecture: Background, Business Case (reduced duplication of effort, increased integration of activities, improved operational capabilities), Baseline (technology baseline currently in place within DOE), Vision (guiding principles for future DOE Information Architecture), Standards Process, Policy and Process Integration (describes relations between information architecture and business processes), and Next Steps. Following each section is a scenario. A glossary of terms is provided.

  5. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy

    2014-05-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  6. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2014-01-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  7. Foundations of Digital Methods : Query Design

    NARCIS (Netherlands)

    Rogers, R.; Schäfer, M.T.; van Es, K.

    2017-01-01

    Broadly speaking digital methods may be considered the deployment of online tools and data for the purposes of social and medium research. More speci cally, they derive from online methods, or methods of the medium, which are reimagined and repurposed for research. The methods to be repurposed are

  8. Mathematical foundation of the optimization-based fluid animation method

    DEFF Research Database (Denmark)

    Erleben, Kenny; Misztal, Marek Krzysztof; Bærentzen, Jakob Andreas

    2011-01-01

    We present the mathematical foundation of a fluid animation method for unstructured meshes. Key contributions not previously treated are the extension to include diffusion forces and higher order terms of non-linear force approximations. In our discretization we apply a fractional step method to ...

  9. Mathematical foundations of the projection-operator method

    International Nuclear Information System (INIS)

    Moore, S.M.

    1979-01-01

    Mathematical foundations are determined for the projection-operator method developed by Zwanzig and Mori and used in the study of cooperative phenomena in non-equilibrium processes. It is shown that the Hilbert space of operators can be taken as the Hilbert-Schmidt class. Comments are made on the possibility of a complete formulation of quantum mechanics in terms of this Hilbert space. (author)

  10. Assessing the foundation of the Trojan Horse Method

    Science.gov (United States)

    Bertulani, C. A.; Hussein, M. S.; Typel, S.

    2018-01-01

    We discuss the foundation of the Trojan Horse Method (THM) within the Inclusive Non-Elastic Breakup (INEB) theory. We demonstrate that the direct part of the INEB cross section, which is of two-step character, becomes, in the DWBA limit of the three-body theory with appropriate approximations and redefinitions, similar in structure to the one-step THM cross section. We also discuss the connection of the THM to the Surrogate Method (SM), which is a genuine two-step process.

  11. Applications of the observational method in deep foundations

    Directory of Open Access Journals (Sweden)

    Fathi M. Abdrabbo

    2012-12-01

    Full Text Available The observational method was introduced into geotechnical engineering to improve both theories and construction techniques. This method was developed to avoid highly conservative assumptions about soil properties in geotechnical design when faced with unavoidable uncertainties of natural ground conditions. The assumptions involved in soil mechanics theories usually differ to a certain extent from reality. These assumptions can be improved by employing an observational database. Thus, theories of geotechnical engineering can be developed by observations during the construction stage. Moreover, precise management of construction work by close observations is essential to avoid risk and to alter the design if needed to match the real conditions. This paper sheds some light on the importance of the observational concept in deep foundations through three case studies. The first one demonstrates the effect of working hypotheses on design outputs of an open caisson of 22 m internal diameter. The other two case studies present the difference between theory and reality during construction stage of auger cast-in-place piles (ACIP in difficult subsoil conditions. Importance of merging the documented theories with the available observations is discussed. The study shows that working hypotheses and engineering models affect the cost and the time required for construction of deep foundations. Field observations are essential during installation of ACIP at a site. Some precautions should be considered when drilling ACIP through sandstone of inclined top surface. These precautions are mainly dependent upon field observations during construction. ACIP can be used effectively in soil formations that have galleries and caves using a cement–bentonite mixture to fill the holes of the unsuccessful piles. Finally, the paper shares a series of practical guidelines with engineering community all over the world that may assist in design and construction of deep

  12. Discussion of the Method to Determine the Ultimate Bearing Capacity of Soil Foundation

    Science.gov (United States)

    Du, Peng; Liu, Xiaoling; Zhang, Yangfu

    2017-12-01

    Combining literature examples, this paper has carried out Contrastive analysis of the theoretical formula method and finite element method about the ultimate bearing capacity of foundation, To verify rationality and superiority of the incremental load method in finite element ABAQUS in solving the bearing capacity of foundation soil. The study can provide certain reference for practical engineering calculation and analysis of foundation bearing capacity.

  13. Load calculation methods for offshore wind turbine foundations

    DEFF Research Database (Denmark)

    Passon, Patrik; Branner, Kim

    2014-01-01

    Calculation of design loads for offshore wind turbine (OWT) foundations is typically performed in a joint effort between wind turbine manufactures and foundation designers (FDs). Ideally, both parties would apply the same fully integrated design tool and model for that purpose. However, such solu...

  14. Foundations of quantum chromodynamics: Perturbative methods in gauge theories

    International Nuclear Information System (INIS)

    Muta, T.

    1986-01-01

    This volume develops the techniques of perturbative QCD in great detail starting with field theory. Aside from extensive treatments of the renormalization group technique, the operator product expansion formalism and their applications to short-distance reactions, this book provides a comprehensive introduction to gauge field theories. Examples and exercises are provided to amplify the discussions on important topics. Contents: Introduction; Elements of Quantum Chromodynamics; The Renormalization Group Method; Asymptotic Freedom; Operator Product Expansion Formalism; Applications; Renormalization Scheme Dependence; Factorization Theorem; Further Applications; Power Corrections; Infrared Problem. Power Correlations; Infrared Problem

  15. Temperature monitoring in large volume spread footing foundations: case study "Parque da Cidade" - São Paulo

    Directory of Open Access Journals (Sweden)

    D. Couto

    Full Text Available ABSTRACT In recent years, the construction of foundation elements from large-volume reinforced concrete is becoming increasingly common. This implies a potential increase in the risk of cracks of thermal origin, due to the heat of hydration of cement. Under these circumstances, these concrete elements need to be treated using the mass concrete theory, widespread in dam construction, but little used when designing buildings. This paper aims to present a case study about the procedures and problems involved in the construction of a spread footing with a volume of approximately 800m³ designed for the foundation of a shopping center in São Paulo, Brazil.

  16. Main issues of pile foundation at waterfront development and its prevention method

    Science.gov (United States)

    Manap, N.; Tan, K. Y.; Syahrom, N.

    2017-12-01

    Pile foundation is widely used in construction and building marine structures. This is because pile foundation is an important structure and should have long-term durability. However, in waterfront development, a lot of issues from the seawater should be considered distinctively because it consists of many problems that can affect the building structure especially the foundation of the building. Thus, a research should be conducted to identify issues of pile foundation at waterfront development and determine its prevention methods. The research was carried out through interviews with the developers and contractors from the projects of Lexis Hibiscus at Port Dickson, Negeri Sembilan and Redevelopment for Deep-Water Facilities at Quay 6 in Pasir Gudang, Johor, Malaysia. The objectives of this research are to identify issues of pile foundation and to determine the prevention methods of pile foundation issues at waterfront development. All respondents agreed that the main issues of pile foundations at waterfront development are the wave and tide condition. The prevention methods of the issue faced at waterfront development that are most frequently used for the pile foundation are coating system and concrete cover. This research is beneficial to all developers and contractors to ensure pile foundations at waterfront development can be protected by using the prevention methods.

  17. Research on horizontal displacement monitoring method of deep foundation pit based on laser projecting sensing technology

    Science.gov (United States)

    Liu, Peng; Xie, Shulin; Zhang, Lixiao; Zhou, Guangyi; Zhao, Xuefeng

    2018-03-01

    A certain level of horizontal displacement will occur during excavation or subsequent construction of deep foundation pit. If the support is improper and the horizontal displacement of the foundation pit is too large, it will cause collapse and even affect the buildings around the foundation pit, which will endanger people's life and property. Therefore, the horizontal displacement monitoring of deep foundation pit becomes more and more important. At present, the electronic total station is often used to monitor the horizontal displacement of the foundation pit, but this monitoring method is expensive, prone to accidental errors, and can not be used for real-time monitoring. Therefore, a method of monitoring the horizontal displacement of deep foundation pit by using laser projection sensing technique is proposed in this paper. The horizontal displacement of the foundation pit is replaced by the displacement of the laser spot emitted by the laser, and the horizontal displacement of the foundation pit can be obtained by identifying the displacement of the laser spot projected on the screen. A series of experiments show that the accuracy of this monitoring method meets the engineering requirements and greatly reduces the cost, which provides a new technology for the displacement monitoring of deep foundation pit.

  18. Colorado Conference on iterative methods. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The conference provided a forum on many aspects of iterative methods. Volume I topics were:Session: domain decomposition, nonlinear problems, integral equations and inverse problems, eigenvalue problems, iterative software kernels. Volume II presents nonsymmetric solvers, parallel computation, theory of iterative methods, software and programming environment, ODE solvers, multigrid and multilevel methods, applications, robust iterative methods, preconditioners, Toeplitz and circulation solvers, and saddle point problems. Individual papers are indexed separately on the EDB.

  19. Two-step nuclear reactions: The Surrogate Method, the Trojan Horse Method and their common foundations

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Mahir S. [DCTA, Instituto Tecnologico de Aeronautica, Sao Jose dos Campos, SP (Brazil); Universidade de Sao Paulo, Instituto de Estudos Avancados, C. P. 72012, Sao Paulo, SP (Brazil); Universidade de Sao Paulo, Instituto de Fisica, C. P. 66318, Sao Paulo, SP (Brazil)

    2017-05-15

    In this Letter I argue that the Surrogate Method, used to extract the fast neutron capture cross section on actinide target nuclei, which has important practical application for the next generation of breeder reactors, and the Trojan Horse Method employed to extract reactions of importance to nuclear astrophysics, have a common foundation, the Inclusive Non-Elastic Breakup (INEB) Theory. Whereas the Surrogate Method relies on the premise that the extracted neutron cross section in a (d, p) reaction is predominantly a compound-nucleus one, the Trojan Horse Method assumes a predominantly direct process for the secondary reaction induced by the surrogate fragment. In general, both methods contain both direct and compound contributions, and I show how these seemingly distinct methods are in fact the same but at different energies and different kinematic regions. The unifying theory is the rather well developed INEB theory. (orig.)

  20. Two-step nuclear reactions: The Surrogate Method, the Trojan Horse Method and their common foundations

    International Nuclear Information System (INIS)

    Hussein, Mahir S.

    2017-01-01

    In this Letter I argue that the Surrogate Method, used to extract the fast neutron capture cross section on actinide target nuclei, which has important practical application for the next generation of breeder reactors, and the Trojan Horse Method employed to extract reactions of importance to nuclear astrophysics, have a common foundation, the Inclusive Non-Elastic Breakup (INEB) Theory. Whereas the Surrogate Method relies on the premise that the extracted neutron cross section in a (d, p) reaction is predominantly a compound-nucleus one, the Trojan Horse Method assumes a predominantly direct process for the secondary reaction induced by the surrogate fragment. In general, both methods contain both direct and compound contributions, and I show how these seemingly distinct methods are in fact the same but at different energies and different kinematic regions. The unifying theory is the rather well developed INEB theory. (orig.)

  1. The evaluation method of soil-spring for the analyses of foundation structures on layered bedsoil

    International Nuclear Information System (INIS)

    Satoh, S.; Sasaki, F.

    1985-01-01

    When performing the finite element method analysis of foundation structures, such as mat slab of reactor buildings and turbine buildings, it is very important to evaluate and model the soil-spring mechanism between foundation and soil correctly. In this model, this paper presents the method in which soil-spring mechanism is evaluated from the theoretical solution. In this theory the semi-infinite elastic solid is assumed to be made of multi-layered soil systems. From the analytical example, it is concluded that the stress analysis of foundation structures on multi-layered soil systems cannot be evaluated by the conventional methods. (orig.)

  2. Method and apparatus for imaging volume data

    International Nuclear Information System (INIS)

    Drebin, R.; Carpenter, L.C.

    1987-01-01

    An imaging system projects a two dimensional representation of three dimensional volumes where surface boundaries and objects internal to the volumes are readily shown, and hidden surfaces and the surface boundaries themselves are accurately rendered by determining volume elements or voxels. An image volume representing a volume object or data structure is written into memory. A color and opacity is assigned to each voxel within the volume and stored as a red (R), green (G), blue (B), and opacity (A) component, three dimensional data volume. The RGBA assignment for each voxel is determined based on the percentage component composition of the materials represented in the volume, and thus, the percentage of color and transparency associated with those materials. The voxels in the RGBA volume are used as mathematical filters such that each successive voxel filter is overlayed over a prior background voxel filter. Through a linear interpolation, a new background filter is determined and generated. The interpolation is successively performed for all voxels up to the front most voxel for the plane of view. The method is repeated until all display voxels are determined for the plane of view. (author)

  3. Calculation of foundation response to spatially varying ground motion by finite element method

    International Nuclear Information System (INIS)

    Wang, F.; Gantenbein, F.

    1995-01-01

    This paper presents a general method to compute the response of a rigid foundation of arbitrary shape resting on a homogeneous or multilayered elastic soil when subjected to a spatially varying ground motion. The foundation response is calculated from the free-field ground motion and the contact tractions between the foundation and the soil. The spatial variation of ground motion in this study is introduced by a coherence function and the contact tractions are obtained numerically using the Finite Element Method in the process of calculating the dynamic compliance of the foundation. Applications of this method to a massless rigid disc supported on an elastic half space and to that founded on an elastic medium consisting of a layer of constant thickness supported on an elastic half space are described. The numerical results obtained are in very good agreement with analytical solutions published in the literature. (authors). 5 refs., 8 figs

  4. The Hartree-Fock seniority method and its foundation

    International Nuclear Information System (INIS)

    Gomez, J.M.G.; Prieto, C.

    1987-01-01

    The seniority scheme is discussed in the framewok of quasi-spin formalism. It is shown that the ground-state wave function of the seniority scheme can be determined self-consistently from a set of Hartree-Fock seniority equations derived from the variational prinicple. The method takes into account the mean-field and the pairing correlations in nuclei at the same time. Angular momentum and particle number are exactly conserved. (author)

  5. Interesting Developments in Testing Methods Applied to Foundation Piles

    Science.gov (United States)

    Sobala, Dariusz; Tkaczyński, Grzegorz

    2017-10-01

    Both: piling technologies and pile testing methods are a subject of current development. New technologies, providing larger diameters or using in-situ materials, are very demanding in terms of providing proper quality of execution of works. That concerns the material quality and continuity which define the integral strength of pile. On the other side we have the capacity of the ground around the pile and its ability to carry the loads transferred by shaft and pile base. Inhomogeneous nature of soils and a relatively small amount of tested piles imposes very good understanding of small amount of results. In some special cases the capacity test itself form an important cost in the piling contract. This work presents a brief description of selected testing methods and authors remarks based on cooperation with Universities constantly developing new ideas. Paper presents some experience based remarks on integrity testing by means of low energy impact (low strain) and introduces selected (Polish) developments in the field of closed-end pipe piles testing based on bi-directional loading, similar to Osterberg idea, but without sacrificial hydraulic jack. Such test is suitable especially when steel piles are used for temporary support in the rivers, where constructing of conventional testing appliance with anchor piles or kentledge meets technical problems. According to the author’s experience, such tests were not yet used on the building site but they bring a real potential especially, when the displacement control can be provided from the river bank using surveying techniques.

  6. Nonlinear Conservation Laws and Finite Volume Methods

    Science.gov (United States)

    Leveque, Randall J.

    Introduction Software Notation Classification of Differential Equations Derivation of Conservation Laws The Euler Equations of Gas Dynamics Dissipative Fluxes Source Terms Radiative Transfer and Isothermal Equations Multi-dimensional Conservation Laws The Shock Tube Problem Mathematical Theory of Hyperbolic Systems Scalar Equations Linear Hyperbolic Systems Nonlinear Systems The Riemann Problem for the Euler Equations Numerical Methods in One Dimension Finite Difference Theory Finite Volume Methods Importance of Conservation Form - Incorrect Shock Speeds Numerical Flux Functions Godunov's Method Approximate Riemann Solvers High-Resolution Methods Other Approaches Boundary Conditions Source Terms and Fractional Steps Unsplit Methods Fractional Step Methods General Formulation of Fractional Step Methods Stiff Source Terms Quasi-stationary Flow and Gravity Multi-dimensional Problems Dimensional Splitting Multi-dimensional Finite Volume Methods Grids and Adaptive Refinement Computational Difficulties Low-Density Flows Discrete Shocks and Viscous Profiles Start-Up Errors Wall Heating Slow-Moving Shocks Grid Orientation Effects Grid-Aligned Shocks Magnetohydrodynamics The MHD Equations One-Dimensional MHD Solving the Riemann Problem Nonstrict Hyperbolicity Stiffness The Divergence of B Riemann Problems in Multi-dimensional MHD Staggered Grids The 8-Wave Riemann Solver Relativistic Hydrodynamics Conservation Laws in Spacetime The Continuity Equation The 4-Momentum of a Particle The Stress-Energy Tensor Finite Volume Methods Multi-dimensional Relativistic Flow Gravitation and General Relativity References

  7. Data Mining Foundations and Intelligent Paradigms Volume 2 Statistical, Bayesian, Time Series and other Theoretical Aspects

    CERN Document Server

    Jain, Lakhmi

    2012-01-01

    Data mining is one of the most rapidly growing research areas in computer science and statistics. In Volume 2 of this three volume series, we have brought together contributions from some of the most prestigious researchers in theoretical data mining. Each of the chapters is self contained. Statisticians and applied scientists/ engineers will find this volume valuable. Additionally, it provides a sourcebook for graduate students interested in the current direction of research in data mining.

  8. Solving hyperbolic equations with finite volume methods

    CERN Document Server

    Vázquez-Cendón, M Elena

    2015-01-01

    Finite volume methods are used in numerous applications and by a broad multidisciplinary scientific community. The book communicates this important tool to students, researchers in training and academics involved in the training of students in different science and technology fields. The selection of content is based on the author’s experience giving PhD and master courses in different universities. In the book the introduction of new concepts and numerical methods go together with simple exercises, examples and applications that contribute to reinforce them. In addition, some of them involve the execution of MATLAB codes. The author promotes an understanding of common terminology with a balance between mathematical rigor and physical intuition that characterizes the origin of the methods. This book aims to be a first contact with finite volume methods. Once readers have studied it, they will be able to follow more specific bibliographical references and use commercial programs or open source software withi...

  9. Method of measuring a liquid pool volume

    Science.gov (United States)

    Garcia, G.V.; Carlson, N.M.; Donaldson, A.D.

    1991-03-19

    A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools is disclosed, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figures.

  10. Development and analysis of finite volume methods

    International Nuclear Information System (INIS)

    Omnes, P.

    2010-05-01

    This document is a synthesis of a set of works concerning the development and the analysis of finite volume methods used for the numerical approximation of partial differential equations (PDEs) stemming from physics. In the first part, the document deals with co-localized Godunov type schemes for the Maxwell and wave equations, with a study on the loss of precision of this scheme at low Mach number. In the second part, discrete differential operators are built on fairly general, in particular very distorted or nonconforming, bidimensional meshes. These operators are used to approach the solutions of PDEs modelling diffusion, electro and magneto-statics and electromagnetism by the discrete duality finite volume method (DDFV) on staggered meshes. The third part presents the numerical analysis and some a priori as well as a posteriori error estimations for the discretization of the Laplace equation by the DDFV scheme. The last part is devoted to the order of convergence in the L2 norm of the finite volume approximation of the solution of the Laplace equation in one dimension and on meshes with orthogonality properties in two dimensions. Necessary and sufficient conditions, relatively to the mesh geometry and to the regularity of the data, are provided that ensure the second-order convergence of the method. (author)

  11. Discrete singular convolution method for the analysis of Mindlin plates on elastic foundations

    International Nuclear Information System (INIS)

    Civalek, Omer; Acar, Mustafa Hilmi

    2007-01-01

    The method of discrete singular convolution (DSC) is used for the bending analysis of Mindlin plates on two-parameter elastic foundations for the first time. Two different realizations of singular kernels, such as the regularized Shannon's delta (RSD) kernel and Lagrange delta sequence (LDS) kernel, are selected as singular convolution to illustrate the present algorithm. The methodology and procedures are presented and bending problems of thick plates on elastic foundations are studied for different boundary conditions. The influence of foundation parameters and shear deformation on the stress resultants and deflections of the plate have been investigated. Numerical studies are performed and the DSC results are compared well with other analytical solutions and some numerical results

  12. Study on monitoring of deep foundation pit with SMW engineering method plus anchor cable retaining structure

    Science.gov (United States)

    Chen, Wenzhao; Cui, Wenping

    2018-03-01

    The SMW method has many advantages, such as little influence on the surrounding environment, good watertight performance, wide range of application, short construction period, low cost and so on. In this paper, we chose the SMW engineering method combined with anchor cable to support structure in the second phase deep foundation pit of Jinan LuJinDongCheng as the research object, monitored and analysed the horizontal displacement of the pile top, Peripheral surface subsidence and internal force of the anchor cable in the foundation pit. We also discussed the displacement, internal force of anchor cable and the settlement of surrounding environment in the excavation of foundation pit and in different stages of construction. Conclusion:(1)The maximum horizontal displacement of the retaining structure is closely related to the depth and time of excavation, the construction of anchor cable can well limit the deformation of pile body; (2)Groundwater seepage caused by foundation pit dewatering will change the effective stress of soil. The change of groundwater level has an important influence on the working behavior of smw anchor cable supporting structure.

  13. Topology optimization using the finite volume method

    DEFF Research Database (Denmark)

    in this presentation is focused on a prototype model for topology optimization of steady heat diffusion. This allows for a study of the basic ingredients in working with FVM methods when dealing with topology optimization problems. The FVM and FEM based formulations differ both in how one computes the design...... derivative of the system matrix K and in how one computes the discretized version of certain objective functions. Thus for a cost function for minimum dissipated energy (like minimum compliance for an elastic structure) one obtains an expression c = u^\\T \\tilde{K}u $, where \\tilde{K} is different from K...... the well known Reuss lower bound. [1] Bendsøe, M.P.; Sigmund, O. 2004: Topology Optimization - Theory, Methods, and Applications. Berlin Heidelberg: Springer Verlag [2] Versteeg, H. K.; W. Malalasekera 1995: An introduction to Computational Fluid Dynamics: the Finite Volume Method. London: Longman...

  14. Finite Volume Method for Unstructured Grid

    International Nuclear Information System (INIS)

    Casmara; Kardana, N.D.

    1997-01-01

    The success of a computational method depends on the solution algorithm and mesh generation techniques. cell distributions are needed, which allow the solution to be calculated over the entire body surface with sufficient accuracy. to handle the mesh generation for multi-connected region such as multi-element bodies, the unstructured finite volume method will be applied. the advantages of the unstructured meshes are it provides a great deal more flexibility for generating meshes about complex geometries and provides a natural setting for the use of adaptive meshing. the governing equations to be discretized are inviscid and rotational euler equations. Applications of the method will be evaluated on flow around single and multi-component bodies

  15. Homotopy perturbation method for free vibration analysis of beams on elastic foundation

    International Nuclear Information System (INIS)

    Ozturk, Baki; Coskun, Safa Bozkurt; Koc, Mehmet Zahid; Atay, Mehmet Tarik

    2010-01-01

    In this study, the homotopy perturbation method (HPM) is applied for free vibration analysis of beam on elastic foundation. This numerical method is applied on a previously available case study. Analytical solutions and frequency factors are evaluated for different ratios of axial load N acting on the beam to Euler buckling load, N r . The application of HPM for the particular problem in this study gives results which are in excellent agreement with both analytical solutions and the variational iteration method (VIM) solutions for the case considered in this study and the differential transform method (DTM) results available in the literature.

  16. Using gas blow methods to realize accurate volume measurement of radioactivity liquid

    International Nuclear Information System (INIS)

    Zhang Caiyun

    2010-01-01

    For liquid which has radioactivity, Realized the accurate volume measurement uncertainty less than 0.2% (k=2) by means of gas blow methods presented in the 'American National Standard-Nuclear Material Control-Volume Calibration Methods(ANSI N15.19-1989)' and the 'ISO Committee Drafts (ISO/TC/85/SC 5N 282 )' and Explored a set methods of Data Processing. In the article, the major problems is to solve data acquisition and function foundation and measurement uncertainty estimate. (authors)

  17. Analytical Method Used to Calculate Pile Foundations with the Widening Up on a Horizontal Static Impact

    Science.gov (United States)

    Kupchikova, N. V.; Kurbatskiy, E. N.

    2017-11-01

    This paper presents a methodology for the analytical research solutions for the work pile foundations with surface broadening and inclined side faces in the ground array, based on the properties of Fourier transform of finite functions. The comparative analysis of the calculation results using the suggested method for prismatic piles, piles with surface broadening prismatic with precast piles and end walls with precast wedges on the surface is described.

  18. Radioisotopic methods for quality control of works and studies while constructing foundations and underground structures

    International Nuclear Information System (INIS)

    Smorodinov, M.I.

    1980-01-01

    The data on the use of radioisotope methods of quality control of various kinds of construction works when building foundations and underground constructions and when carrying out scientific research, are presented. Devices and equipment are described, their block diagrams are presented. The experience in using radioisotope devices to control the quality of construction works, is presented. The problems of economic effectivenes of works using radioisotope devices are solved

  19. Foundation Structure

    DEFF Research Database (Denmark)

    2009-01-01

    Method of installing a bucket foundation structure comprising one, two, three or more skirts, into soils in a controlled manner. The method comprises two stages: a first stage being a design phase and the second stage being an installation phase. In the first stage, design parameters are determined...... relating to the loads on the finished foundation structure; soil profile on the location; allowable installation tolerances, which parameters are used to estimate the minimum diameter and length of the skirts of the bucket. The bucket size is used to simulate load situations and penetration into foundation...

  20. Large deflection analysis of laminated composite plates resting on nonlinear elastic foundations by the method of discrete singular convolution

    International Nuclear Information System (INIS)

    Baltacioglu, A.K.; Civalek, O.; Akgoez, B.; Demir, F.

    2011-01-01

    This paper presents nonlinear static analysis of a rectangular laminated composite thick plate resting on nonlinear two-parameter elastic foundation with cubic nonlinearity. The plate formulation is based on first-order shear deformation theory (FSDT). The governing equation of motion for a rectangular laminated composite thick plate is derived by using the von Karman equation. The nonlinear static deflections of laminated plates on elastic foundation are investigated using the discrete singular convolution method. The effects of foundation and geometric parameters of plates on nonlinear deflections are investigated. The validity of the present method is demonstrated by comparing the present results with those available in the literature. - Highlights: → Large deflection analysis of laminated composite plates are investigated. → As foundation, nonlinear elastic models have been used firstly. → The effects of three-parameter foundation are investigated in detail.

  1. Method of calculating pilestrip foundations in case of karst hole formation

    Directory of Open Access Journals (Sweden)

    Gotman Al'fred Leonidovich

    2014-02-01

    Full Text Available The paper presents pile strip foundations in the areas with karst risk. The analysis of karst hole formation mechanism shows the lateral soil pressure on the piles caused by the downfallen soil on the hole rims, which transfers around the hole edges during karst hole formation. In this case, the horizontal pressure of the pile reactive force in the area of the pile connection with the raft is transferred to the raft. Pile failure at the hole boundaries will lead to the increase of the raft bearing distance above the karst hole. The inadequate raft bearing capacity can provoke the emergency situation. The existing Codes on karst protective foundations design do not contain the analysis of pile and raft horizontal pressure under the downfallen soil.The goal of this work is to develop the method of pile strip foundations analysis in the areas with karst risk in case of karst hole formation. The analysis of stress-strain state of the system “foundation soil — pile foundation” was carried out using numerical modeling in geotechnical program MIDAS GTS. As a result of numerical investigations, the diagrams of lateral soil pressure onto the piles and the raft are plotted. The pile pressure is approximated with the linear or bilinear function in dependence on geometrical dimensions of the karst hole and strength characteristics of soil that generates the horizontal pressure.In the Codes, the analysis of a pile under lateral soil pressure is given for a pile with the free end. In the problem examined, the pile head has the hinged bearing in place of the connection with the raft. In view of the given boundary data, the pile design scheme is plotted. The inner forces and displacements of the pile are determined by integrating the differential equation of a pile bending. The consistent integrations are evaluated out of the boundary conditions. The boundary values of inner forces and displacements are evaluated from the equality conditions of

  2. Chemical Method of Urine Volume Measurement

    Science.gov (United States)

    Petrack, P.

    1967-01-01

    A system has been developed and qualified as flight hardware for the measurement of micturition volumes voided by crewmen during Gemini missions. This Chemical Urine Volume Measurement System (CUVMS) is used for obtaining samples of each micturition for post-flight volume determination and laboratory analysis for chemical constituents of physiological interest. The system is versatile with respect to volumes measured, with a capacity beyond the largest micturition expected to be encountered, and with respect to mission duration of inherently indefinite length. The urine sample is used for the measurement of total micturition volume by a tracer dilution technique, in which a fixed, predetermined amount of tritiated water is introduced and mixed into the voided urine, and the resulting concentration of the tracer in the sample is determined with a liquid scintillation spectrometer. The tracer employed does not interfere with the analysis for the chemical constituents of the urine. The CUVMS hardware consists of a four-way selector valve in which an automatically operated tracer metering pump is incorporated, a collection/mixing bag, and tracer storage accumulators. The assembled system interfaces with a urine receiver at the selector valve inlet, sample bags which connect to the side of the selector valve, and a flexible hose which carries the excess urine to the overboard drain connection. Results of testing have demonstrated system volume measurement accuracy within the specification limits of +/-5%, and operating reliability suitable for system use aboard the GT-7 mission, in which it was first used.

  3. Dynamic-stiffness matrix of embedded and pile foundations by indirect boundary-element method

    International Nuclear Information System (INIS)

    Wolf, J.P.; Darbre, G.R.

    1984-01-01

    The boundary-integral equation method is well suited for the calculation of the dynamic-stiffness matrix of foundations embedded in a layered visco-elastic halfspace (or a transmitting boundary of arbitrary shape), which represents an unbounded domain. It also allows pile groups to be analyzed, taking pile-soil-pile interaction into account. The discretization of this boundary-element method is restricted to the structure-soil interface. All trial functions satisfy exactly the field equations and the radiation condition at infinity. In the indirect boundary-element method distributed source loads of initially unknown intensities act on a source line located in the excavated part of the soil and are determined such that the prescribed boundary conditions on the structure-soil interface are satisfied in an average sense. In the two-dimensional case the variables are expanded in a Fourier integral in the wave number domain, while in three dimensions, Fourier series in the circumferential direction and bessel functions of the wave number domain, while in three dimensions, Fourier series in the circumferential direction and Bessel functions of the wave number in the radial direction are selected. Accurate results arise with a small number of parameters of the loads acting on a source line which should coincide with the structure-soil interface. In a parametric study the dynamic-stiffness matrices of rectangular foundations of various aspect ratios embedded in a halfplane and in a layer built-in at its base are calculated. For the halfplane, the spring coefficients for the translational directions hardly depend on the embedment, while the corresponding damping coefficients increase for larger embedments, this tendency being more pronounced in the horizontal direction. (orig.)

  4. Eclecticism as the foundation of meta-theoretical, mixed methods and interdisciplinary research in social sciences.

    Science.gov (United States)

    Kroos, Karmo

    2012-03-01

    This article examines the value of "eclecticism" as the foundation of meta-theoretical, mixed methods and interdisciplinary research in social sciences. On the basis of the analysis of the historical background of the concept, it is first suggested that eclecticism-based theoretical scholarship in social sciences could benefit from the more systematic research method that has been developed for synthesizing theoretical works under the name metatheorizing. Second, it is suggested that the mixed methods community could base its research approach on philosophical eclecticism instead of pragmatism because the basic idea of eclecticism is much more in sync with the nature of the combined research tradition. Finally, the Kuhnian frame is used to support the argument for interdisciplinary research and, hence, eclecticism in social sciences (rather than making an argument against multiple paradigms). More particularly, it is suggested that integrating the different (inter)disciplinary traditions and schools into one is not necessarily desirable at all in social sciences because of the complexity and openness of the research field. If it is nevertheless attempted, experience in economics suggests that paradigmatic unification comes at a high price.

  5. Translating the foundational model of anatomy into french using knowledge-based and lexical methods

    Directory of Open Access Journals (Sweden)

    Merabti Tayeb

    2011-10-01

    Full Text Available Abstract Background The Foundational Model of Anatomy (FMA is the reference ontology regarding human anatomy. FMA vocabulary was integrated into the Health Multi Terminological Portal (HMTP developed by CISMeF based on the CISMeF Information System which also includes 26 other terminologies and controlled vocabularies, mainly in French. However, FMA is primarily in English. In this context, the translation of FMA English terms into French could also be useful for searching and indexing French anatomy resources. Various studies have investigated automatic methods to assist the translation of medical terminologies or create multilingual medical vocabularies. The goal of this study was to facilitate the translation of FMA vocabulary into French. Methods We compare two types of approaches to translate the FMA terms into French. The first one is UMLS-based on the conceptual information of the UMLS metathesaurus. The second method is lexically-based on several Natural Language Processing (NLP tools. Results The UMLS-based approach produced a translation of 3,661 FMA terms into French whereas the lexical approach produced a translation of 3,129 FMA terms into French. A qualitative evaluation was made on 100 FMA terms translated by each method. For the UMLS-based approach, among the 100 translations, 52% were manually rated as "very good" and only 7% translations as "bad". For the lexical approach, among the 100 translations, 47% were rated as "very good" and 20% translations as "bad". Conclusions Overall, a low rate of translations were demonstrated by the two methods. The two approaches permitted us to semi-automatically translate 3,776 FMA terms from English into French, this was to added to the existing 10,844 French FMA terms in the HMTP (4,436 FMA French terms and 6,408 FMA terms manually translated.

  6. Boundary integral equation methods and numerical solutions thin plates on an elastic foundation

    CERN Document Server

    Constanda, Christian; Hamill, William

    2016-01-01

    This book presents and explains a general, efficient, and elegant method for solving the Dirichlet, Neumann, and Robin boundary value problems for the extensional deformation of a thin plate on an elastic foundation. The solutions of these problems are obtained both analytically—by means of direct and indirect boundary integral equation methods (BIEMs)—and numerically, through the application of a boundary element technique. The text discusses the methodology for constructing a BIEM, deriving all the attending mathematical properties with full rigor. The model investigated in the book can serve as a template for the study of any linear elliptic two-dimensional problem with constant coefficients. The representation of the solution in terms of single-layer and double-layer potentials is pivotal in the development of a BIEM, which, in turn, forms the basis for the second part of the book, where approximate solutions are computed with a high degree of accuracy. The book is intended for graduate students and r...

  7. Safety assessment of a shallow foundation using the random finite element method

    Science.gov (United States)

    Zaskórski, Łukasz; Puła, Wojciech

    2015-04-01

    A complex structure of soil and its random character are reasons why soil modeling is a cumbersome task. Heterogeneity of soil has to be considered even within a homogenous layer of soil. Therefore an estimation of shear strength parameters of soil for the purposes of a geotechnical analysis causes many problems. In applicable standards (Eurocode 7) there is not presented any explicit method of an evaluation of characteristic values of soil parameters. Only general guidelines can be found how these values should be estimated. Hence many approaches of an assessment of characteristic values of soil parameters are presented in literature and can be applied in practice. In this paper, the reliability assessment of a shallow strip footing was conducted using a reliability index β. Therefore some approaches of an estimation of characteristic values of soil properties were compared by evaluating values of reliability index β which can be achieved by applying each of them. Method of Orr and Breysse, Duncan's method, Schneider's method, Schneider's method concerning influence of fluctuation scales and method included in Eurocode 7 were examined. Design values of the bearing capacity based on these approaches were referred to the stochastic bearing capacity estimated by the random finite element method (RFEM). Design values of the bearing capacity were conducted for various widths and depths of a foundation in conjunction with design approaches DA defined in Eurocode. RFEM was presented by Griffiths and Fenton (1993). It combines deterministic finite element method, random field theory and Monte Carlo simulations. Random field theory allows to consider a random character of soil parameters within a homogenous layer of soil. For this purpose a soil property is considered as a separate random variable in every element of a mesh in the finite element method with proper correlation structure between points of given area. RFEM was applied to estimate which theoretical

  8. Vibration analysis of Euler-Bernoulli beam with open cracks on elastic foundations using differential transformation method and generalized differential quadrature method

    International Nuclear Information System (INIS)

    Shin, Young Jae; Hwang, Ki Sup; Yun, Jong Hak

    2006-01-01

    The main purpose of this paper is to apply Differential Transformation Method(DTM) and Generalized Differential Quadrature Method(GDQM) to vibration analysis of Euler-Bernoulli beam with open cracks on elastic foundation. In this paper the concepts of DTM and GDQM were briefly introduced. The governing equation of motion of the beam with open cracks on elastic foundation is derived. The cracks are modeled by massless substitute spring. The effects of the crack location, size and the foundation constants, on the natural frequencies of the beam, are investigated. Numerical calculations are carried out and compared with previous published results

  9. Hilbert's 'Foundations of Physics': Gravitation and electromagnetism within the axiomatic method

    Science.gov (United States)

    Brading, K. A.; Ryckman, T. A.

    2008-01-01

    In November and December 1915, Hilbert presented two communications to the Göttingen Academy of Sciences under the common title 'The Foundations of Physics'. Versions of each eventually appeared in the Nachrichten of the Academy. Hilbert's first communication has received significant reconsideration in recent years, following the discovery of printer's proofs of this paper, dated 6 December 1915. The focus has been primarily on the 'priority dispute' over the Einstein field equations. Our contention, in contrast, is that the discovery of the December proofs makes it possible to see the thematic linkage between the material that Hilbert cut from the published version of the first communication and the content of the second, as published in 1917. The latter has been largely either disregarded or misinterpreted, and our aim is to show that (a) Hilbert's two communications should be regarded as part of a wider research program within the overarching framework of 'the axiomatic method' (as Hilbert expressly stated was the case), and (b) the second communication is a fine and coherent piece of work within this framework, whose principal aim is to address an apparent tension between general invariance and causality (in the precise sense of Cauchy determination), pinpointed in Theorem I of the first communication. This is not the same problem as that found in Einstein's 'hole argument'-something that, we argue, never confused Hilbert.

  10. The spectral volume method as applied to transport problems

    International Nuclear Information System (INIS)

    McClarren, Ryan G.

    2011-01-01

    We present a new spatial discretization for transport problems: the spectral volume method. This method, rst developed by Wang for computational fluid dynamics, divides each computational cell into several sub-cells and enforces particle balance on each of these sub-cells. Also, these sub-cells are used to build a polynomial reconstruction in the cell. The idea of dividing cells into many cells is a generalization of the simple corner balance and other similar schemes. The spectral volume method preserves particle conservation and preserves the asymptotic diffusion limit. We present results from the method on two transport problems in slab geometry using discrete ordinates and second through sixth order spectral volume schemes. The numerical results demonstrate the accuracy and preservation of the diffusion limit of the spectral volume method. Future work will explore possible bene ts of the scheme for high-performance computing and for resolving diffusive boundary layers. (author)

  11. Starting Where the People Are: The African Medical and Research Foundation (AMREF). Carnegie Quarterly, Volume XXXII, Number 2.

    Science.gov (United States)

    Carnegie Quarterly, 1987

    1987-01-01

    This issue of the "Carnegie Quarterly" describes three projects that are being conducted by the African Medical and Research Foundation (AMREF). The projects are the following: (1) building community participation in health care at Lake Kenyatta; (2) the role of community education in disease control among the Turkana people at…

  12. Comparison of different precondtioners for nonsymmtric finite volume element methods

    Energy Technology Data Exchange (ETDEWEB)

    Mishev, I.D.

    1996-12-31

    We consider a few different preconditioners for the linear systems arising from the discretization of 3-D convection-diffusion problems with the finite volume element method. Their theoretical and computational convergence rates are compared and discussed.

  13. Three-dimensional reconstruction volume: a novel method for volume measurement in kidney cancer.

    Science.gov (United States)

    Durso, Timothy A; Carnell, Jonathan; Turk, Thomas T; Gupta, Gopal N

    2014-06-01

    The role of volumetric estimation is becoming increasingly important in the staging, management, and prognostication of benign and cancerous conditions of the kidney. We evaluated the use of three-dimensional reconstruction volume (3DV) in determining renal parenchymal volumes (RPV) and renal tumor volumes (RTV). We compared 3DV with the currently available methods of volume assessment and determined its interuser reliability. RPV and RTV were assessed in 28 patients who underwent robot-assisted laparoscopic partial nephrectomy for kidney cancer. Patients with a preoperative creatinine level of kidney pre- and postsurgery overestimated 3D reconstruction volumes by 15% to 102% and 12% to 101%, respectively. In addition, volumes obtained from 3DV displayed high interuser reliability regardless of experience. 3DV provides a highly reliable way of assessing kidney volumes. Given that 3DV takes into account visible anatomy, the differences observed using previously published methods can be attributed to the failure of geometry to accurately approximate kidney or tumor shape. 3DV provides a more accurate, reproducible, and clinically useful tool for urologists looking to improve patient care using analysis related to volume.

  14. Topology optimization using the finite volume method

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Allan; Bendsøe, Martin P.; Sigmund, Ole

    2005-01-01

    in this presentation is focused on a prototype model for topology optimization of steady heat diffusion. This allows for a study of the basic ingredients in working with FVM methods when dealing with topology optimization problems. The FVM and FEM based formulations differ both in how one computes the design...... derivative of the system matrix $\\mathbf K$ and in how one computes the discretized version of certain objective functions. Thus for a cost function for minimum dissipated energy (like minimum compliance for an elastic structure) one obtains an expression $ c = \\mathbf u^\\T \\tilde{\\mathbf K} \\mathbf u...... the arithmetic and harmonic average with the latter being the well known Reuss lower bound. [1] Bendsøe, MP and Sigmund, O 2004: Topology Optimization - Theory, Methods, and Applications. Berlin Heidelberg: Springer Verlag [2] Versteeg, HK and Malalasekera, W 1995: An introduction to Computational Fluid Dynamics...

  15. Evaluation of Bearing Capacity of Strip Foundation Subjected to Eccentric Inclined Loads Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Ahmed Majeed Ali

    2016-08-01

    Full Text Available In real conditions of structures, foundations like retaining walls, industrial machines and platforms in offshore areas are commonly subjected to eccentrically inclined loads. This type of loading significantly affects the overall stability of shallow foundations due to exposing the foundation into two components of loads (horizontal and vertical and consequently reduces the bearing capacity Based on a numerical analysis performed using finite element software (Plaxis 3D Foundation, the behavior of model strip foundation rested on dry sand under the effect of eccentric inclined loads with different embedment ratios (D/B ranging from (0-1 has been explored. The results display that, the bearing capacity of strip foundation is noticeably decreased with the increase of inclination angle (α and eccentricity ratio (e/B. As well as, a reduction factor (RF expression was appointed to measure the degree of decreasing in the bearing capacity when the model footing is subjected to eccentric inclined load. It was observed that, the (RF decreases as the embedment ratio increases. Moreover, the test results also exhibit that, the model footing bearing capacity is reduced by about (69% when the load inclination is varied from (0° to 20° and the model footing is on the surface. While, the rate of decreasing in the bearing capacity was found to be (58%, for both cases of footing when they are at embedment ratios of (0.5 and 1.0. Also, a comparative study was carried out between the present results and previous experimental test results under the same conditions (soil properties and boundary condition. A good agreement was obtained between the predicted bearing capacities for the two related studies.

  16. Optimal Design, Reliability And Sensitivity Analysis Of Foundation Plate

    Directory of Open Access Journals (Sweden)

    Tvrdá Katarína

    2015-12-01

    Full Text Available This paper deals with the optimal design of thickness of a plate rested on Winkler’s foundation. First order method was used for the optimization, while maintaining different restrictive conditions. The aim is to obtain a minimum volume of the foundation plate. At the end some probabilistic and safety analysis of the deflection of the foundation using LHS Monte Carlo method are presented.

  17. Computational Methods in Stochastic Dynamics Volume 2

    CERN Document Server

    Stefanou, George; Papadopoulos, Vissarion

    2013-01-01

    The considerable influence of inherent uncertainties on structural behavior has led the engineering community to recognize the importance of a stochastic approach to structural problems. Issues related to uncertainty quantification and its influence on the reliability of the computational models are continuously gaining in significance. In particular, the problems of dynamic response analysis and reliability assessment of structures with uncertain system and excitation parameters have been the subject of continuous research over the last two decades as a result of the increasing availability of powerful computing resources and technology.   This book is a follow up of a previous book with the same subject (ISBN 978-90-481-9986-0) and focuses on advanced computational methods and software tools which can highly assist in tackling complex problems in stochastic dynamic/seismic analysis and design of structures. The selected chapters are authored by some of the most active scholars in their respective areas and...

  18. Hydrothermal analysis in engineering using control volume finite element method

    CERN Document Server

    Sheikholeslami, Mohsen

    2015-01-01

    Control volume finite element methods (CVFEM) bridge the gap between finite difference and finite element methods, using the advantages of both methods for simulation of multi-physics problems in complex geometries. In Hydrothermal Analysis in Engineering Using Control Volume Finite Element Method, CVFEM is covered in detail and applied to key areas of thermal engineering. Examples, exercises, and extensive references are used to show the use of the technique to model key engineering problems such as heat transfer in nanofluids (to enhance performance and compactness of energy systems),

  19. Volume Sculpting Using the Level-Set Method

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas; Christensen, Niels Jørgen

    2002-01-01

    In this paper, we propose the use of the Level--Set Method as the underlying technology of a volume sculpting system. The main motivation is that this leads to a very generic technique for deformation of volumetric solids. In addition, our method preserves a distance field volume representation....... A scaling window is used to adapt the Level--Set Method to local deformations and to allow the user to control the intensity of the tool. Level--Set based tools have been implemented in an interactive sculpting system, and we show sculptures created using the system....

  20. The volume of fluid method in spherical coordinates

    NARCIS (Netherlands)

    Janse, A.M.C.; Janse, A.M.C.; Dijk, P.E.; Kuipers, J.A.M.

    2000-01-01

    The volume of fluid (VOF) method is a numerical technique to track the developing free surfaces of liquids in motion. This method can, for example, be applied to compute the liquid flow patterns in a rotating cone reactor. For this application a spherical coordinate system is most suited. The novel

  1. Evaluation of the dynamic responses of high rise buildings with respect to the direct methods for soil-foundation-structure interaction effects and comparison with the approximate methods

    Directory of Open Access Journals (Sweden)

    Jahangir Khazaei

    2017-08-01

    Full Text Available In dynamic analysis, modeling of soil medium is ignored because of the infinity and complexity of the soil behavior and so the important effects of these terms are neglected, while the behavior of the soil under the structure plays an important role in the response of the structure during an earthquake. In fact, the soil layers and soil foundation structure interaction phenomena can increase the applied seismic forces during earthquakes that has been examined with different methods. In this paper, effects of soil foundation structure interaction on a steel high rise building has been modeled using Abaqus software for nonlinear dynamic analysis with finite element direct method and simulation of infinite boundary condition for soil medium and also approximate Cone model. In the direct method, soil, structure and foundation are modeled altogether. In other hand, for using Cone model as a simple model, dynamic stiffness coefficients have been employed to simulate soil with considering springs and dashpots in all degree of freedom. The results show that considering soil foundation structure interaction cause increase in maximum lateral displacement of structure and the friction coefficient of soil-foundation interface can alter the responses of structure. It was also observed that the results of the approximate methods have good agreement for engineering demands.

  2. New simple method for fast and accurate measurement of volumes

    International Nuclear Information System (INIS)

    Frattolillo, Antonio

    2006-01-01

    A new simple method is presented, which allows us to measure in just a few minutes but with reasonable accuracy (less than 1%) the volume confined inside a generic enclosure, regardless of the complexity of its shape. The technique proposed also allows us to measure the volume of any portion of a complex manifold, including, for instance, pipes and pipe fittings, valves, gauge heads, and so on, without disassembling the manifold at all. To this purpose an airtight variable volume is used, whose volume adjustment can be precisely measured; it has an overall capacity larger than that of the unknown volume. Such a variable volume is initially filled with a suitable test gas (for instance, air) at a known pressure, as carefully measured by means of a high precision capacitive gauge. By opening a valve, the test gas is allowed to expand into the previously evacuated unknown volume. A feedback control loop reacts to the resulting finite pressure drop, thus contracting the variable volume until the pressure exactly retrieves its initial value. The overall reduction of the variable volume achieved at the end of this process gives a direct measurement of the unknown volume, and definitively gets rid of the problem of dead spaces. The method proposed actually does not require the test gas to be rigorously held at a constant temperature, thus resulting in a huge simplification as compared to complex arrangements commonly used in metrology (gas expansion method), which can grant extremely accurate measurement but requires rather expensive equipments and results in time consuming methods, being therefore impractical in most applications. A simple theoretical analysis of the thermodynamic cycle and the results of experimental tests are described, which demonstrate that, in spite of its simplicity, the method provides a measurement accuracy within 0.5%. The system requires just a few minutes to complete a single measurement, and is ready immediately at the end of the process. The

  3. Safe jack-up method permits repairs of tank bottoms and foundations

    International Nuclear Information System (INIS)

    de Wit, J.

    1991-01-01

    The oil and chemical industries use many thousands of steel tanks to store crude oil, oil products, and chemical liquids. The majority of these tanks are 30-40 years old. Tank bottoms are likely to begin leaking in the coming years, as these tanks get older. The European technique of jacking up a tank and repairing its foundation allows the thorough inspection of the underside of the tank bottom and the removal of saturated foundation material. And the possibility of soil and groundwater pollution is reduced to a minimum. With good, regular maintenance, the lifetime of a storage tank is very long. But experience has shown that special attention should be paid to the tank's bottom. Tank bottoms are only 5 or 6 mm thick, and in the last 10 years, an increasing number of leaks in tank bottoms have been reported. Tank foundations are affected by these leaks. This article describes the resulting procedure, which is used successfully in many European countries, but is not yet common in the U.S

  4. Cellwise conservative unsplit advection for the volume of fluid method

    DEFF Research Database (Denmark)

    Comminal, Raphaël; Spangenberg, Jon; Hattel, Jesper Henri

    2015-01-01

    We present a cellwise conservative unsplit (CCU) advection scheme for the volume of fluid method (VOF) in 2D. Contrary to other schemes based on explicit calculations of the flux balances, the CCU advection adopts a cellwise approach where the pre-images of the control volumes are traced......-overlapping donating regions and pre-images with conforming edges to their neighbors, resulting in the conservativeness and the boundedness (liquid volume fraction inside the interval [0, 1]) of the CCU advection scheme. Finally, the update of the liquid volume fractions is computed from the intersections of the pre......-image polygons with the reconstructed interfaces. The CCU scheme is tested on several benchmark tests for the VOF advection, together with the standard piecewise linear interface calculation (PLIC). The geometrical errors of the CCU compare favorably with other unsplit VOF-PLIC schemes. Finally, potential...

  5. Teaching Thermal Hydraulics & Numerical Methods: An Introductory Control Volume Primer

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, D.S.

    2004-10-03

    This paper covers the basics of the implementation of the control volume method in the context of the Homogeneous Equilibrium Model (HEM)(T/H) code using the conservation equations of mass, momentum, and energy. This primer uses the advection equation as a template. The discussion will cover the basic equations of the control volume portion of the course in the primer, which includes the advection equation, numerical methods, along with the implementation of the various equations via FORTRAN into computer programs and the final result for a three equation HEM code and its validation.

  6. Copper Mountain conference on iterative methods: Proceedings: Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This volume (the second of two) contains information presented during the last two days of the Copper Mountain Conference on Iterative Methods held April 9-13, 1996 at Copper Mountain, Colorado. Topics of the sessions held these two days include domain decomposition, Krylov methods, computational fluid dynamics, Markov chains, sparse and parallel basic linear algebra subprograms, multigrid methods, applications of iterative methods, equation systems with multiple right-hand sides, projection methods, and the Helmholtz equation. Selected papers indexed separately for the Energy Science and Technology Database.

  7. Different partial volume correction methods lead to different conclusions

    DEFF Research Database (Denmark)

    Greve, Douglas N; Salat, David H; Bowen, Spencer L

    2016-01-01

    A cross-sectional group study of the effects of aging on brain metabolism as measured with (18)F-FDG-PET was performed using several different partial volume correction (PVC) methods: no correction (NoPVC), Meltzer (MZ), Müller-Gärtner (MG), and the symmetric geometric transfer matrix (SGTM) usin...

  8. A method of measuring a molten metal liquid pool volume

    Science.gov (United States)

    Garcia, G.V.; Carlson, N.M., Donaldson, A.D.

    1990-12-12

    A method of measuring a molten metal liquid pool volume and in particular molten titanium liquid pools, including the steps of (a) generating an ultrasonic wave at the surface of the molten metal liquid pool, (b) shining a light on the surface of a molten metal liquid pool, (c) detecting a change in the frequency of light, (d) detecting an ultrasonic wave echo at the surface of the molten metal liquid pool, and (e) computing the volume of the molten metal liquid. 3 figs.

  9. ABIM Foundation

    Science.gov (United States)

    ... In conjunction with the… mailchi.mp View on Facebook ABIM Foundation shared Business Radio Powered by The Wharton School's post. 2 days ago View on Facebook ABIM Foundation 2 days ago The Android version ...

  10. Iterative algorithm for the volume integral method for magnetostatics problems

    International Nuclear Information System (INIS)

    Pasciak, J.E.

    1980-11-01

    Volume integral methods for solving nonlinear magnetostatics problems are considered in this paper. The integral method is discretized by a Galerkin technique. Estimates are given which show that the linearized problems are well conditioned and hence easily solved using iterative techniques. Comparisons of iterative algorithms with the elimination method of GFUN3D shows that the iterative method gives an order of magnitude improvement in computational time as well as memory requirements for large problems. Computational experiments for a test problem as well as a double layer dipole magnet are given. Error estimates for the linearized problem are also derived

  11. Copper Mountain conference on iterative methods: Proceedings: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This volume (one of two) contains information presented during the first three days of the Copper Mountain Conference on Iterative Methods held April 9-13, 1996 at Copper Mountain, Colorado. Topics of the sessions held these three days included nonlinear systems, parallel processing, preconditioning, sparse matrix test collections, first-order system least squares, Arnoldi`s method, integral equations, software, Navier-Stokes equations, Euler equations, Krylov methods, and eigenvalues. The top three papers from a student competition are also included. Selected papers indexed separately for the Energy Science and Technology Database.

  12. Radionuclide method for blood volume determination in kidneys

    International Nuclear Information System (INIS)

    Trindev, P.; Nikolov, D.; Shejretova, E.; Garcheva-Tsacheva, M.

    1989-01-01

    The method is applied in nephrology for diagnosing changes in blood circulation of the kidneys. The blood volume of each kidney is determined separately by perfusion angioscintigraphy (PAS) with improved accuracy. The method consists in intravenous injection of 300-450 MBq 99m Tc for in-vivo labelling of the erythrocytes. About 30 images are registered every 2 sec, and through zones of interest perfusion histograms of kidneys are derived. Ten minutes later kidneys images (one full-face and two profiles) are registered. Correction coefficients for kidneys depth are derived and the activities registered according to full-face images and amplitudes of perfusion histograms are corrected. The activity of 1 ml blood is determined from blood sample of the patient. The blood volume of each kidney is expressed as a ratio of the activity corrected for background and depth and the activity of 1 ml blood of the sample. 1 claim

  13. Foundations of measurement

    CERN Document Server

    Suppes, Patrick

    1989-01-01

    Foundations of Measurement offers the most coherently organized treatment of the topics and issues central to measurement. Much of the research involved has been scattered over several decades and a multitude of journals--available in many instances only to specialties. With the publication of Volumes two and three of this important work, Foundations of Measurement is the most comprehensive presentation in the area of measurement.

  14. Introductory guide to foundations

    CSIR Research Space (South Africa)

    Donaldson, GW

    1973-01-01

    Full Text Available . The secret of successful foundations is knowing just how much the subsoil can support. As one goes deeper, the ability of the ground to support a load becomes greater so that the foundation engineer can choose between deep foundations and the expense... beginstoinaease. When the house is ~ ~ p l e t e d it shelters the gmund f f ~ m sun and wind and the moisture content i- wen more rapidly- Leaking pipes and sewers increase the volume of water fed to the clay while ornamental trees planted around the house...

  15. Development op finite volume methods for fluid dynamics

    International Nuclear Information System (INIS)

    Delcourte, S.

    2007-09-01

    We aim to develop a finite volume method which applies to a greater class of meshes than other finite volume methods, restricted by orthogonality constraints. We build discrete differential operators over the three staggered tessellations needed for the construction of the method. These operators verify some analogous properties to those of the continuous operators. At first, the method is applied to the Div-Curl problem, which can be viewed as a building block of the Stokes problem. Then, the Stokes problem is dealt with with various boundary conditions. It is well known that when the computational domain is polygonal and non-convex, the order of convergence of numerical methods is deteriorated. Consequently, we have studied how an appropriate local refinement is able to restore the optimal order of convergence for the Laplacian problem. At last, we have discretized the non-linear Navier-Stokes problem, using the rotational formulation of the convection term, associated to the Bernoulli pressure. With an iterative algorithm, we are led to solve a saddle-point problem at each iteration. We give a particular interest to this linear problem by testing some pre-conditioners issued from finite elements, which we adapt to our method. Each problem is illustrated by numerical results on arbitrary meshes, such as strongly non-conforming meshes. (author)

  16. Construction of large-thickness sand cushions for NPP foundations

    International Nuclear Information System (INIS)

    Krantsfel'd, Ya.L.; Losievskaya, I.K.; Kovalenko, R.P.; Mutalipov, A.

    1982-01-01

    A study is made on some technological peculiarities of preparation of NPP foundations and control methods of foundation density. As an example the experience of cement-sand foundation construction for two 900 MW power-units at the Koeberg South Africa NPP is briefly described. The experience of artificial foundation construction at this NPP indicates both the possibility of obtaining the required quality of cement-sand cushions and commercial construction of large volume of such cushions by acceptable rates and the necessity of unification of work quality characteristics

  17. Methods for obtaining a uniform volume concentration of implanted ions

    International Nuclear Information System (INIS)

    Reutov, V.F.

    1995-01-01

    Three simple practical methods of irradiations with high energy particles providing the conditions for obtaining a uniform volume concentration of the implanted ions in the massive samples are described in the present paper. Realization of the condition of two-sided irradiation of a plane sample during its rotation in the flux of the projectiles is the basis of the first method. The use of free air as a filter with varying absorbent ability due to movement of the irradiated sample along ion beam brought to the atmosphere is at the basis of the second method of uniform ion alloying. The third method for obtaining a uniform volume concentration of the implanted ions in a massive sample consists of irradiation of a sample through the absorbent filter in the shape of a foil curved according to the parabolic law moving along its surface. The first method is the most effective for obtaining a great number of the samples, for example, for mechanical tests, the second one - for irradiation in different gaseous media, and the third one - for obtaining high concentrations of the implanted ions under controlled (regulated) thermal and deformation conditions. 2 refs., 7 figs

  18. Grouting for Pile Foundation Improvement

    NARCIS (Netherlands)

    Van der Stoel, A.E.C.

    2001-01-01

    The aim of this research was to examine the use of grouting methods for pile foundation improvement, a generic term that is used here to define both foundation renovation (increasing the bearing capacity of a pile foundation that has insufficient bearing capacity) and foundation protection

  19. Derivation Method for the Foundation Boundaries of Hydraulic Numerical Simulation Models Based on the Elastic Boussinesq Solution

    Directory of Open Access Journals (Sweden)

    Jintao Song

    2015-01-01

    Full Text Available The foundation boundaries of numerical simulation models of hydraulic structures dominated by a vertical load are investigated. The method used is based on the stress formula for fundamental solutions to semi-infinite space body elastic mechanics under a vertical concentrated force. The limit method is introduced into the original formula, which is then partitioned and analyzed according to the direction of the depth extension of the foundation. The point load will be changed to a linear load with a length of 2a. Inverse proportion function assumptions are proposed at parameter a and depth l of the calculation points to solve the singularity questions of elastic stress in a semi-infinite space near the ground. Compared with the original formula, changing the point load to a linear load with a length of 2a is more reasonable. Finally, the boundary depth criterion of a hydraulic numerical simulation model is derived and applied to determine the depth boundary formula for gravity dam numerical simulations.

  20. A Method of Function Space for Vertical Impedance Function of a Circular Rigid Foundation on a Transversely Isotropic Ground

    Directory of Open Access Journals (Sweden)

    Morteza Eskandari-Ghadi

    2014-06-01

    Full Text Available This paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semi-infinite transversely isotropic alluvium. To this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. The governing partial differential equation for the potential function is solved via implementing Hankel integral transforms in radial direction. The vertical and radial components of displacement vector are determined with the use of transformed displacement-potential function relationships. The mixed boundary conditions at the surface are satisfied by specifying the traction between the rigid foundation and the underneath alluvium in a special function space introduced in this paper, where the vertical displacements are forced to satisfy the rigid boundary condition. Through exercising these restraints, the normal traction and then the vertical impedance function are obtained. The results are then compared with the existing results in the literature for the simpler case of isotropic half-space, which shows an excellent agreement. Eventually, the impedance functions are presented in terms of dimensionless frequency for different materials. The method presented here may be used to obtain the impedance function in any other direction as well as in buried footing in layered media.

  1. Development op finite volume methods for fluid dynamics; Developpement de methodes de volumes finis pour la mecanique des fluides

    Energy Technology Data Exchange (ETDEWEB)

    Delcourte, S

    2007-09-15

    We aim to develop a finite volume method which applies to a greater class of meshes than other finite volume methods, restricted by orthogonality constraints. We build discrete differential operators over the three staggered tessellations needed for the construction of the method. These operators verify some analogous properties to those of the continuous operators. At first, the method is applied to the Div-Curl problem, which can be viewed as a building block of the Stokes problem. Then, the Stokes problem is dealt with with various boundary conditions. It is well known that when the computational domain is polygonal and non-convex, the order of convergence of numerical methods is deteriorated. Consequently, we have studied how an appropriate local refinement is able to restore the optimal order of convergence for the Laplacian problem. At last, we have discretized the non-linear Navier-Stokes problem, using the rotational formulation of the convection term, associated to the Bernoulli pressure. With an iterative algorithm, we are led to solve a saddle-point problem at each iteration. We give a particular interest to this linear problem by testing some pre-conditioners issued from finite elements, which we adapt to our method. Each problem is illustrated by numerical results on arbitrary meshes, such as strongly non-conforming meshes. (author)

  2. Genomic similarity and kernel methods I: advancements by building on mathematical and statistical foundations.

    Science.gov (United States)

    Schaid, Daniel J

    2010-01-01

    Measures of genomic similarity are the basis of many statistical analytic methods. We review the mathematical and statistical basis of similarity methods, particularly based on kernel methods. A kernel function converts information for a pair of subjects to a quantitative value representing either similarity (larger values meaning more similar) or distance (smaller values meaning more similar), with the requirement that it must create a positive semidefinite matrix when applied to all pairs of subjects. This review emphasizes the wide range of statistical methods and software that can be used when similarity is based on kernel methods, such as nonparametric regression, linear mixed models and generalized linear mixed models, hierarchical models, score statistics, and support vector machines. The mathematical rigor for these methods is summarized, as is the mathematical framework for making kernels. This review provides a framework to move from intuitive and heuristic approaches to define genomic similarities to more rigorous methods that can take advantage of powerful statistical modeling and existing software. A companion paper reviews novel approaches to creating kernels that might be useful for genomic analyses, providing insights with examples [1]. Copyright © 2010 S. Karger AG, Basel.

  3. HSC Foundation

    Science.gov (United States)

    ... in disability information or services and that add value to our existing programs. The Foundation also works to bring additional support to initiatives by serving as funding partners on projects that have local impact and national relevance. Supporting a Continuum of Care The HSC Foundation ...

  4. Corporate Foundations

    DEFF Research Database (Denmark)

    Herlin, Heidi; Thusgaard Pedersen, Janni

    2013-01-01

    action between business and NGOs through convening, translation, collaboration, and mediation. Our study provides valuable insights into the tri-part relationship of company foundation NGO by discussing the implications of corporate foundations taking an active role in the realm of corporate social...... responsibility (CSR). The paper hence illuminates the fascinating and overlooked role of corporate foundations as potential bridges between business and civil society. It also informs theory on boundary organizations by clarifying challenges and limits of such institutions.......This paper aims to explore the potential of Danish corporate foundations as boundary organizations facilitating relationships between their founding companies and non-governmental organizations (NGOs). Hitherto, research has been silent about the role of corporate foundations in relation to cross...

  5. Physical foundations of image quality in nuclear medicine. Methods for its evaluation

    International Nuclear Information System (INIS)

    Perez Diaz, Marlen; Diaz Rizo, Oscar

    2007-01-01

    The present paper describes the main physical factors which characterize image quality in Nuclear Medicine from the physical and mathematical point of view. A conceptual description of how image system (gamma camera) degrades the information emitted by the object is also presented. A critical review of some qualitative and quantitative methods for grading image quality, collateral to equipment quality control, follows this material. Among these methods we present the ROC analysis, Clustering Techniques and Discriminant Analysis. As a part of the two last ones, we also analyze the main factors which determine image quality and how they produce changes in the quantitative physical variables measured on the images. A comparison among the methods is also presented, remarking their utility to check image quality, as well as the main advantages and disadvantages of each one (au)

  6. Seismic resistance evaluation methods for foundation ground of nuclear power plant and for critical civil engineering structures

    International Nuclear Information System (INIS)

    1985-01-01

    The Ground Integrity Subcommittee was established in September, 1979, in the Japan Society of Civil Engineers to systematize the relation among the survey, test, analysis, evaluation, design and construction of diverse geological features and grounds. The results were put in order in March, 1984. In this paper, the main results of examination by the Aseismatic Design Working Group consisted of three groups are reported. It was decided to evaluate the aseismatic capability of the foundation ground and surrounding slopes of reactor buildings and important outdoor structures so that the function of supporting buildings and installations is not impaired, and that influence is not exerted on the maintenance of the function of buildings and installations. The basic concept, design earthquake force and standard values for the evaluation of the aseismatic stability of the foundation ground and surrounding slopes of reactor buildings are described. The basic concept and the comparison of various methods of aseismatic calculation are reported regarding the evaluation of the aseismatic stability of important outdoor structures in civil engineering field. (Kako, I.)

  7. A volume-based method for denoising on curved surfaces

    KAUST Repository

    Biddle, Harry; von Glehn, Ingrid; Macdonald, Colin B.; Marz, Thomas

    2013-01-01

    We demonstrate a method for removing noise from images or other data on curved surfaces. Our approach relies on in-surface diffusion: we formulate both the Gaussian diffusion and Perona-Malik edge-preserving diffusion equations in a surface-intrinsic way. Using the Closest Point Method, a recent technique for solving partial differential equations (PDEs) on general surfaces, we obtain a very simple algorithm where we merely alternate a time step of the usual Gaussian diffusion (and similarly Perona-Malik) in a small 3D volume containing the surface with an interpolation step. The method uses a closest point function to represent the underlying surface and can treat very general surfaces. Experimental results include image filtering on smooth surfaces, open surfaces, and general triangulated surfaces. © 2013 IEEE.

  8. A volume-based method for denoising on curved surfaces

    KAUST Repository

    Biddle, Harry

    2013-09-01

    We demonstrate a method for removing noise from images or other data on curved surfaces. Our approach relies on in-surface diffusion: we formulate both the Gaussian diffusion and Perona-Malik edge-preserving diffusion equations in a surface-intrinsic way. Using the Closest Point Method, a recent technique for solving partial differential equations (PDEs) on general surfaces, we obtain a very simple algorithm where we merely alternate a time step of the usual Gaussian diffusion (and similarly Perona-Malik) in a small 3D volume containing the surface with an interpolation step. The method uses a closest point function to represent the underlying surface and can treat very general surfaces. Experimental results include image filtering on smooth surfaces, open surfaces, and general triangulated surfaces. © 2013 IEEE.

  9. The Strutinsky method and its foundation from the Hartree-Fock-Bogoliubov approximation at finite temperature

    International Nuclear Information System (INIS)

    Brack, M.

    1981-01-01

    Strutinsky's shell-correction method is investigated in the framework of the microscopial Hartree-Fock-Bogoliubov method at finite temperature HFBT. Applying the Strutinsky energy averaging consistently to the normal and abnormal density matrices and to the entropy, we define a self-consistently average HFBT system as the solution of a variational problem. From the latter we derive the generalized Strutinsky energy theorem and the explicit expressions for the shell correction of a statistically excited system of BCS quasiparticles. Using numerical results of HF calculations, we demonstrate the convergence of the Strutinsky expansion and estimate the validity of the partical shell-correction approach. We also discuss the close connections of the Strutinsky energy averaging with semiclassical expansions and their usefulness for solving the average nuclear self-consistency problem. In particular we argue that the Hohenberg-Kohn theorem should hold for the averaged HFBT system and we thus provide a justification of the use of semiclassical density functionals. (orig.)

  10. New method for studying the microscopic foundations of the interacting boson model

    International Nuclear Information System (INIS)

    Klein, A.; Vallieres, M.

    1981-01-01

    We describe (i) a mapping, using a multishell seniority basis, from a prescribed subspace of a shell model space to an associated boson space. (ii) A new dynamical procedure for selecting the collective variables within the boson space, based on the invariance of the trace. (iii) A comparison with exact calculations for a multi-level pairing model, to demonstrate that the method works. (orig.)

  11. Forecasting the vibrational behavior of large turbogenerators on elastic foundations in accordance with probabilistic methods

    International Nuclear Information System (INIS)

    Simon, G.

    1990-01-01

    Using advanced calculation programs, the inherent behavior and response behavior of structures can reliably be predetermined. In contrast, the dynamic forces affecting a system, in particular unbalances, are often unkown. From balancing of individual rotors, only the vibration path amplitudes at the measuring points used are known. However, these may originate from quite different unbalance distributions. Using probabilistic methods, however, values for the vibrational behavior of the overall structure can be derived from this. (orig.) [de

  12. Foundation of the semiclassical approximation by means of path integral methods

    International Nuclear Information System (INIS)

    Krisztinkovics, F.

    1984-01-01

    The aim of our study is to find a technically unique semiclassical treatment to describe the collision processes between heavy ions. Thereby it shall be started from a complete quantum mechanical formulation of the collision process. This aim requires: 1. A completely quantum mechanical initial formulation for the whole system, 2. a unique and conceptually clear transition to semiclassics. In order to fulfil the requirements a method is offered which is in closest connection with the Feynman propagator respectively influence functional. (orig./HSI) [de

  13. Teaching Thermal Hydraulics & Numerical Methods: An Introductory Control Volume Primer

    Energy Technology Data Exchange (ETDEWEB)

    D. S. Lucas

    2004-10-01

    A graduate level course for Thermal Hydraulics (T/H) was taught through Idaho State University in the spring of 2004. A numerical approach was taken for the content of this course since the students were employed at the Idaho National Laboratory and had been users of T/H codes. The majority of the students had expressed an interest in learning about the Courant Limit, mass error, semi-implicit and implicit numerical integration schemes in the context of a computer code. Since no introductory text was found the author developed notes taught from his own research and courses taught for Westinghouse on the subject. The course started with a primer on control volume methods and the construction of a Homogeneous Equilibrium Model (HEM) (T/H) code. The primer was valuable for giving the students the basics behind such codes and their evolution to more complex codes for Thermal Hydraulics and Computational Fluid Dynamics (CFD). The course covered additional material including the Finite Element Method and non-equilibrium (T/H). The control volume primer and the construction of a three-equation (mass, momentum and energy) HEM code are the subject of this paper . The Fortran version of the code covered in this paper is elementary compared to its descendants. The steam tables used are less accurate than the available commercial version written in C Coupled to a Graphical User Interface (GUI). The Fortran version and input files can be downloaded at www.microfusionlab.com.

  14. National comparison on volume sample activity measurement methods

    International Nuclear Information System (INIS)

    Sahagia, M.; Grigorescu, E.L.; Popescu, C.; Razdolescu, C.

    1992-01-01

    A national comparison on volume sample activity measurements methods may be regarded as a step toward accomplishing the traceability of the environmental and food chain activity measurements to national standards. For this purpose, the Radionuclide Metrology Laboratory has distributed 137 Cs and 134 Cs water-equivalent solid standard sources to 24 laboratories having responsibilities in this matter. Every laboratory has to measure the activity of the received source(s) by using its own standards, equipment and methods and report the obtained results to the organizer. The 'measured activities' will be compared with the 'true activities'. A final report will be issued, which plans to evaluate the national level of precision of such measurements and give some suggestions for improvement. (Author)

  15. Twenty-first century quantum mechanics Hilbert space to quantum computers mathematical methods and conceptual foundations

    CERN Document Server

    Fano, Guido

    2017-01-01

    This book is designed to make accessible to nonspecialists the still evolving concepts of quantum mechanics and the terminology in which these are expressed. The opening chapters summarize elementary concepts of twentieth century quantum mechanics and describe the mathematical methods employed in the field, with clear explanation of, for example, Hilbert space, complex variables, complex vector spaces and Dirac notation, and the Heisenberg uncertainty principle. After detailed discussion of the Schrödinger equation, subsequent chapters focus on isotropic vectors, used to construct spinors, and on conceptual problems associated with measurement, superposition, and decoherence in quantum systems. Here, due attention is paid to Bell’s inequality and the possible existence of hidden variables. Finally, progression toward quantum computation is examined in detail: if quantum computers can be made practicable, enormous enhancements in computing power, artificial intelligence, and secure communication will result...

  16. The Theoretical and Methodical Foundations of Formation and Development of the Managerial Knowledge of Enterprise

    Directory of Open Access Journals (Sweden)

    Denysiuk Olga V.

    2017-05-01

    Full Text Available The article defines the relationship between the concepts of «managerial competency» and «managerial knowledge of enterprise». By generalizing the conceptual provisions, a typology of the enterprise’s competencies has been developed. In order to clarify the contents of the concept of managerial competency, the classification attributes of the managerial knowledge of enterprise have been allocated. The need to use management standards (management of business processes, staff, quality, projects, and production in the processes of formation and development of the managerial competencies of the enterprise has been substantiated. The composition of the methodical support of formation and development of the managerial competencies of enterprise have been provided.

  17. Geometrically nonlinear dynamic analysis of doubly curved isotropic shells resting on elastic foundation by a combination of harmonic differential quadrature-finite difference methods

    International Nuclear Information System (INIS)

    Civalek, Oemer

    2005-01-01

    The nonlinear dynamic response of doubly curved shallow shells resting on Winkler-Pasternak elastic foundation has been studied for step and sinusoidal loadings. Dynamic analogues of Von Karman-Donnel type shell equations are used. Clamped immovable and simply supported immovable boundary conditions are considered. The governing nonlinear partial differential equations of the shell are discretized in space and time domains using the harmonic differential quadrature (HDQ) and finite differences (FD) methods, respectively. The accuracy of the proposed HDQ-FD coupled methodology is demonstrated by numerical examples. The shear parameter G of the Pasternak foundation and the stiffness parameter K of the Winkler foundation have been found to have a significant influence on the dynamic response of the shell. It is concluded from the present study that the HDQ-FD methodolgy is a simple, efficient, and accurate method for the nonlinear analysis of doubly curved shallow shells resting on two-parameter elastic foundation

  18. Leak testing plan for the Oak Ridge National Laboratory liquid low-level waste systems (active tanks): Revision 2. Volume 1: Regulatory background and plan approach; Volume 2: Methods, protocols, and schedules; Volume 3: Evaluation of the ORNL/LT-823DP differential pressure leak detection method; Appendix to Revision 2: DOE/EPA/TDEC correspondence

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, D.G.; Wise, R.F.; Starr, J.W.; Maresca, J.W. Jr. [Vista Research, Inc., Mountain View, CA (United States)

    1994-11-01

    This document, the Leak Testing Plan for the Oak Ridge National Laboratory Liquid Low-Level Waste System (Active Tanks), comprises three volumes. The first two volumes address the component-based leak testing plan for the liquid low-level waste system at Oak Ridge, while the third volume describes the performance evaluation of the leak detection method that will be used to test this system. Volume 1, describes that portion of the liquid low-level waste system at that will be tested; it provides the regulatory background, especially in terms of the requirements stipulated in the Federal Facilities Agreement, upon which the leak testing plan is based. Volume 1 also describes the foundation of the plan, portions of which were abstracted from existing federal documents that regulate the petroleum and hazardous chemicals industries. Finally, Volume 1 gives an overview the plan, describing the methods that will be used to test the four classes of components in the liquid low-level waste system. Volume 2 takes the general information on component classes and leak detection methods presented in Volume 1 and shows how it applies particularly to each of the individual components. A complete test plan for each of the components is presented, with emphasis placed on the methods designated for testing tanks. The protocol for testing tank systems is described, and general leak testing schedules are presented. Volume 3 describes the results of a performance evaluation completed for the leak testing method that will be used to test the small tanks at the facility (those less than 3,000 gal in capacity). Some of the details described in Volumes 1 and 2 are expected to change as additional information is obtained, as the viability of candidate release detection methods is proven in the Oak Ridge environment, and as the testing program evolves.

  19. Leak testing plan for the Oak Ridge National Laboratory liquid low-level waste systems (active tanks): Revision 2. Volume 1: Regulatory background and plan approach; Volume 2: Methods, protocols, and schedules; Volume 3: Evaluation of the ORNL/LT-823DP differential pressure leak detection method; Appendix to Revision 2: DOE/EPA/TDEC correspondence

    International Nuclear Information System (INIS)

    Douglas, D.G.; Wise, R.F.; Starr, J.W.; Maresca, J.W. Jr.

    1994-11-01

    This document, the Leak Testing Plan for the Oak Ridge National Laboratory Liquid Low-Level Waste System (Active Tanks), comprises three volumes. The first two volumes address the component-based leak testing plan for the liquid low-level waste system at Oak Ridge, while the third volume describes the performance evaluation of the leak detection method that will be used to test this system. Volume 1, describes that portion of the liquid low-level waste system at that will be tested; it provides the regulatory background, especially in terms of the requirements stipulated in the Federal Facilities Agreement, upon which the leak testing plan is based. Volume 1 also describes the foundation of the plan, portions of which were abstracted from existing federal documents that regulate the petroleum and hazardous chemicals industries. Finally, Volume 1 gives an overview the plan, describing the methods that will be used to test the four classes of components in the liquid low-level waste system. Volume 2 takes the general information on component classes and leak detection methods presented in Volume 1 and shows how it applies particularly to each of the individual components. A complete test plan for each of the components is presented, with emphasis placed on the methods designated for testing tanks. The protocol for testing tank systems is described, and general leak testing schedules are presented. Volume 3 describes the results of a performance evaluation completed for the leak testing method that will be used to test the small tanks at the facility (those less than 3,000 gal in capacity). Some of the details described in Volumes 1 and 2 are expected to change as additional information is obtained, as the viability of candidate release detection methods is proven in the Oak Ridge environment, and as the testing program evolves

  20. Vasculitis Foundation

    Science.gov (United States)

    ... Our Board Our Team Anniversary Vasculitis Foundation Newsletters Annual Reports Press Page Literature Order Form Join Contact Us Dream Big Donate Donate Support the VF Through the Amazon Smile Program United Way Giving Ways to Give ...

  1. Marfan Foundation

    Science.gov (United States)

    ... The Marfan Foundation Marfan & Related Disorders What is Marfan Syndrome? What are Related Disorders? What are the Signs? ... Click to see what's happening around the country! Marfan syndrome is a life-threatening genetic disorder, and an ...

  2. CARES Foundation

    Science.gov (United States)

    ... Foundation Video Get Involved EMS and Newborn Screening campaigns Clincal trials Fundraisers Support groups Connect and promote with Social Media: Facebook , Twitter , Instagram and LinkedIn News & Notes from ...

  3. Prediction method of seismic residual deformation of caisson quay wall in liquefied foundation

    Science.gov (United States)

    Wang, Li-Yan; Liu, Han-Long; Jiang, Peng-Ming; Chen, Xiang-Xiang

    2011-03-01

    The multi-spring shear mechanism plastic model in this paper is defined in strain space to simulate pore pressure generation and development in sands under cyclic loading and undrained conditions, and the rotation of principal stresses can also be simulated by the model with cyclic behavior of anisotropic consolidated sands. Seismic residual deformations of typical caisson quay walls under different engineering situations are analyzed in detail by the plastic model, and then an index of liquefaction extent is applied to describe the regularity of seismic residual deformation of caisson quay wall top under different engineering situations. Some correlated prediction formulas are derived from the results of regression analysis between seismic residual deformation of quay wall top and extent of liquefaction in the relative safety backfill sand site. Finally, the rationality and the reliability of the prediction methods are validated by test results of a 120 g-centrifuge shaking table, and the comparisons show that some reliable seismic residual deformation of caisson quay can be predicted by appropriate prediction formulas and appropriate index of liquefaction extent.

  4. Statistics in science the foundations of statistical methods in biology, physics and economics

    CERN Document Server

    Costantini, Domenico

    1990-01-01

    An inference may be defined as a passage of thought according to some method. In the theory of knowledge it is customary to distinguish deductive and non-deductive inferences. Deductive inferences are truth preserving, that is, the truth of the premises is preserved in the con­ clusion. As a result, the conclusion of a deductive inference is already 'contained' in the premises, although we may not know this fact until the inference is performed. Standard examples of deductive inferences are taken from logic and mathematics. Non-deductive inferences need not preserve truth, that is, 'thought may pass' from true premises to false conclusions. Such inferences can be expansive, or, ampliative in the sense that the performances of such inferences actually increases our putative knowledge. Standard non-deductive inferences do not really exist, but one may think of elementary inductive inferences in which conclusions regarding the future are drawn from knowledge of the past. Since the body of scientific knowledge i...

  5. Porosity, Bulk Density, and Volume Reduction During Drying: Review of Measurement Methods and Coefficient Determinations

    NARCIS (Netherlands)

    Qiu, J.; Khalloufi, S.; Martynenko, A.; Dalen, van G.; Schutyser, M.A.I.; Almeida-Rivera, C.

    2015-01-01

    Several experimental methods for measuring porosity, bulk density and volume reduction during drying of foodstuff are available. These methods include among others geometric dimension, volume displacement, mercury porosimeter, micro-CT, and NMR. However, data on their accuracy, sensitivity, and

  6. Method of reducing the volume of radioactive waste

    International Nuclear Information System (INIS)

    Buckley, L.P.; Burrill, K.A.; Desjardins, C.D.; Salter, R.S.

    1984-01-01

    There is provided a method of reducing the volume of radioactive waste, comprising: pyrolyzing the radioactive waste in the interior of a vessel, while passing superheated steam through the vessel at a temperature in the range 500 to 700 degrees C, a pressure in the range 1.0 to 3.5 MPa, and at a flow rate in the range 4 to 50 mL/s/m 3 of the volume of the vessel interior, to cause pyrohydrolysis of the waste and to remove carbon-containing components of the pyrolyzed waste from the vessel as gaseous oxides, leaving an ash residue in the vessel. Entrained particles present with the gaseous oxides are filtered and acidic vapours present with the gaseous oxides are removed by solid sorbent. Steam and any organic substances present with the gaseous oxides are condensed and the ash is removed from the vessel. The radioactive waste may be deposited upon an upper screen in the vessel, so that a substantial portion of the pyrolysis of the radioactive waste takes place while the radioactive waste is on the upper screen, and pyrolyzed waste falls through the upper screen onto a lower screen, where another substantial portion of the pyrohydrolysis takes place. The ash residue falls through the lower screen

  7. Method of volume-reducing processing for radioactive wastes

    International Nuclear Information System (INIS)

    Sato, Koei; Yamauchi, Noriyuki; Hirayama, Toshihiko.

    1985-01-01

    Purpose: To process the processing products of radioactive liquid wastes and burnable solid wastes produced from nuclear facilities into stable solidification products by heat melting. Method: At first, glass fiber wastes of contaminated air filters are charged in a melting furnace. Then, waste products obtained through drying, sintering, incineration, etc. are mixed with a proper amount of glass fibers and charged into the melting furnace. Both of the charged components are heated to a temperature at which the glass fibers are melted. The burnable materials are burnt out to provide a highly volume-reduced products. When the products are further heated to a temperature at which metals or metal oxides of a higher melting point than the glass fiber, the glass fibers and the metals or metal oxides are fused to each other to be combined in a molecular structure into more stabilized products. The products are excellent in strength, stability, durability and leaching resistance at ambient temperature. (Kamimura, M.)

  8. Viscous wing theory development. Volume 1: Analysis, method and results

    Science.gov (United States)

    Chow, R. R.; Melnik, R. E.; Marconi, F.; Steinhoff, J.

    1986-01-01

    Viscous transonic flows at large Reynolds numbers over 3-D wings were analyzed using a zonal viscid-inviscid interaction approach. A new numerical AFZ scheme was developed in conjunction with the finite volume formulation for the solution of the inviscid full-potential equation. A special far-field asymptotic boundary condition was developed and a second-order artificial viscosity included for an improved inviscid solution methodology. The integral method was used for the laminar/turbulent boundary layer and 3-D viscous wake calculation. The interaction calculation included the coupling conditions of the source flux due to the wing surface boundary layer, the flux jump due to the viscous wake, and the wake curvature effect. A method was also devised incorporating the 2-D trailing edge strong interaction solution for the normal pressure correction near the trailing edge region. A fully automated computer program was developed to perform the proposed method with one scalar version to be used on an IBM-3081 and two vectorized versions on Cray-1 and Cyber-205 computers.

  9. Foundations of stochastic analysis

    CERN Document Server

    Rao, M M; Lukacs, E

    1981-01-01

    Foundations of Stochastic Analysis deals with the foundations of the theory of Kolmogorov and Bochner and its impact on the growth of stochastic analysis. Topics covered range from conditional expectations and probabilities to projective and direct limits, as well as martingales and likelihood ratios. Abstract martingales and their applications are also discussed. Comprised of five chapters, this volume begins with an overview of the basic Kolmogorov-Bochner theorem, followed by a discussion on conditional expectations and probabilities containing several characterizations of operators and mea

  10. Estimating traffic volume on Wyoming low volume roads using linear and logistic regression methods

    Directory of Open Access Journals (Sweden)

    Dick Apronti

    2016-12-01

    Full Text Available Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effective alternative to taking traffic counts. This is because traditional traffic counts are expensive and impractical for low priority roads. The purpose of this paper is to present the development of two alternative means of cost-effectively estimating traffic volumes for low volume roads in Wyoming and to make recommendations for their implementation. The study methodology involves reviewing existing studies, identifying data sources, and carrying out the model development. The utility of the models developed were then verified by comparing actual traffic volumes to those predicted by the model. The study resulted in two regression models that are inexpensive and easy to implement. The first regression model was a linear regression model that utilized pavement type, access to highways, predominant land use types, and population to estimate traffic volume. In verifying the model, an R2 value of 0.64 and a root mean square error of 73.4% were obtained. The second model was a logistic regression model that identified the level of traffic on roads using five thresholds or levels. The logistic regression model was verified by estimating traffic volume thresholds and determining the percentage of roads that were accurately classified as belonging to the given thresholds. For the five thresholds, the percentage of roads classified correctly ranged from 79% to 88%. In conclusion, the verification of the models indicated both model types to be useful for accurate and cost-effective estimation of traffic volumes for low volume Wyoming roads. The models developed were recommended for use in traffic volume estimations for low volume roads in pavement management and environmental impact assessment studies.

  11. Arthritis Foundation

    Science.gov (United States)

    ... Vision Leadership News Partners & Sponsors Careers Code of Ethics Financials Annual Report Contact Us Privacy Policy Terms & Conditions Donate Press Store Blog Community Local Offices Kids Get Arthritis Too Español Arthritis Today Social Media Newsletters Sign Up for E-Newsletters Arthritis Foundation ...

  12. ACARP Project C10059. ACARP manual of modern coal testing methods. Volume 2: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Sakurovs, R.; Creelman, R.; Pohl, J.; Juniper, L. [CSIRO Energy Technology, Sydney, NSW (Australia)

    2002-07-01

    The Manual summarises the purpose, applicability, and limitations of a range of standard and modern coal testing methods that have potential to assist the coal company technologist to better evaluate coal performance. It is presented in two volumes. This second volume provides more detailed information regarding the methods discussed in Volume 1.

  13. Well balanced finite volume methods for nearly hydrostatic flows

    International Nuclear Information System (INIS)

    Botta, N.; Klein, R.; Langenberg, S.; Luetzenkirchen, S.

    2004-01-01

    In numerical approximations of nearly hydrostatic flows, a proper representation of the dominant hydrostatic balance is of crucial importance: unbalanced truncation errors can induce unacceptable spurious motions, e.g., in dynamical cores of models for numerical weather prediction (NWP) in particular near steep topography. In this paper we develop a new strategy for the construction of discretizations that are 'well-balanced' with respect to dominant hydrostatics. The classical idea of formulating the momentum balance in terms of deviations of pressure from a balanced background distribution is realized here through local, time dependent hydrostatic reconstructions. Balanced discretizations of the pressure gradient and of the gravitation source term are achieved through a 'discrete Archimedes' buoyancy principle'. This strategy is applied to extend an explicit standard finite volume Godunov-type scheme for compressible flows with minimal modifications. The resulting method has the following features: (i) It inherits its conservation properties from the underlying base scheme. (ii) It is exactly balanced, even on curvilinear grids, for a large class of near-hydrostatic flows. (iii) It solves the full compressible flow equations without reference to a background state that is defined for an entire vertical column of air. (iv) It is robust with respect to details of the implementation, such as the choice of slope limiting functions, or the particularities of boundary condition discretizations

  14. Design method for marine direct drive volume control ahead actuator

    Directory of Open Access Journals (Sweden)

    WANG Haiyang

    2018-02-01

    Full Text Available [Objectives] In order to reduce the size, weight and auxiliary system configuration of marine ahead actuators, this paper proposes a kind of direct drive volume control electro-hydraulic servo ahead actuator. [Methods] The protruding and indenting control of the servo oil cylinder are realized through the forward and reverse of the bidirectional working gear pump, and the flow matching valve implements the self-locking of the ahead actuator in the target position. The mathematical model of the ahead actuator is established, and an integral separation fuzzy PID controller designed. On this basis, using AMESim software to build a simulation model of the ahead actuator, and combined with testing, this paper completes an analysis of the control strategy research and dynamic and static performance of the ahead actuator. [Results] The experimental results agree well with the simulation results and verify the feasibility of the ahead actuator's design. [Conclusions] The research results of this paper can provide valuable references for the integration and miniaturization design of marine ahead actuators.

  15. MRI definition of target volumes using fuzzy logic method for three-dimensional conformal radiation therapy

    International Nuclear Information System (INIS)

    Caudrelier, Jean-Michel; Vial, Stephane; Gibon, David; Kulik, Carine; Fournier, Charles; Castelain, Bernard; Coche-Dequeant, Bernard; Rousseau, Jean

    2003-01-01

    Purpose: Three-dimensional (3D) volume determination is one of the most important problems in conformal radiation therapy. Techniques of volume determination from tomographic medical imaging are usually based on two-dimensional (2D) contour definition with the result dependent on the segmentation method used, as well as on the user's manual procedure. The goal of this work is to describe and evaluate a new method that reduces the inaccuracies generally observed in the 2D contour definition and 3D volume reconstruction process. Methods and Materials: This new method has been developed by integrating the fuzziness in the 3D volume definition. It first defines semiautomatically a minimal 2D contour on each slice that definitely contains the volume and a maximal 2D contour that definitely does not contain the volume. The fuzziness region in between is processed using possibility functions in possibility theory. A volume of voxels, including the membership degree to the target volume, is then created on each slice axis, taking into account the slice position and slice profile. A resulting fuzzy volume is obtained after data fusion between multiorientation slices. Different studies have been designed to evaluate and compare this new method of target volume reconstruction and a classical reconstruction method. First, target definition accuracy and robustness were studied on phantom targets. Second, intra- and interobserver variations were studied on radiosurgery clinical cases. Results: The absolute volume errors are less than or equal to 1.5% for phantom volumes calculated by the fuzzy logic method, whereas the values obtained with the classical method are much larger than the actual volumes (absolute volume errors up to 72%). With increasing MRI slice thickness (1 mm to 8 mm), the phantom volumes calculated by the classical method are increasing exponentially with a maximum absolute error up to 300%. In contrast, the absolute volume errors are less than 12% for phantom

  16. A new electric method for non-invasive continuous monitoring of stroke volume and ventricular volume-time curves

    Directory of Open Access Journals (Sweden)

    Konings Maurits K

    2012-08-01

    Full Text Available Abstract Background In this paper a new non-invasive, operator-free, continuous ventricular stroke volume monitoring device (Hemodynamic Cardiac Profiler, HCP is presented, that measures the average stroke volume (SV for each period of 20 seconds, as well as ventricular volume-time curves for each cardiac cycle, using a new electric method (Ventricular Field Recognition with six independent electrode pairs distributed over the frontal thoracic skin. In contrast to existing non-invasive electric methods, our method does not use the algorithms of impedance or bioreactance cardiography. Instead, our method is based on specific 2D spatial patterns on the thoracic skin, representing the distribution, over the thorax, of changes in the applied current field caused by cardiac volume changes during the cardiac cycle. Since total heart volume variation during the cardiac cycle is a poor indicator for ventricular stroke volume, our HCP separates atrial filling effects from ventricular filling effects, and retrieves the volume changes of only the ventricles. Methods ex-vivo experiments on a post-mortem human heart have been performed to measure the effects of increasing the blood volume inside the ventricles in isolation, leaving the atrial volume invariant (which can not be done in-vivo. These effects have been measured as a specific 2D pattern of voltage changes on the thoracic skin. Furthermore, a working prototype of the HCP has been developed that uses these ex-vivo results in an algorithm to decompose voltage changes, that were measured in-vivo by the HCP on the thoracic skin of a human volunteer, into an atrial component and a ventricular component, in almost real-time (with a delay of maximally 39 seconds. The HCP prototype has been tested in-vivo on 7 human volunteers, using G-suit inflation and deflation to provoke stroke volume changes, and LVot Doppler as a reference technique. Results The ex-vivo measurements showed that ventricular filling

  17. Method for extracting an equivalent Winkler model of the 3D dynamic soil-structure interaction of large-diameter offshore monopile foundations

    NARCIS (Netherlands)

    Versteijlen, W.G.; De Oliveira Barbosa, J.M.; Van Dalen, K.N.; Metrikine, A.

    2015-01-01

    The motivation for this work stems from the offshore wind industry, where designers are faced with a discrepancy between the available design methods and the typical dimensions of the offshore wind foundations that call for other design approaches. Throughout the years, much valuable work has been

  18. Simulation of biological flow and transport in complex geometries using embedded boundary/volume-of-fluid methods

    International Nuclear Information System (INIS)

    Trebotich, David

    2007-01-01

    We have developed a simulation capability to model multiscale flow and transport in complex biological systems based on algorithms and software infrastructure developed under the SciDAC APDEC CET. The foundation of this work is a new hybrid fluid-particle method for modeling polymer fluids in irregular microscale geometries that enables long-time simulation of validation experiments. Both continuum viscoelastic and discrete particle representations have been used to model the constitutive behavior of polymer fluids. Complex flow environment geometries are represented on Cartesian grids using an implicit function. Direct simulation of flow in the irregular geometry is then possible using embedded boundary/volume-of-fluid methods without loss of geometric detail. This capability has been used to simulate biological flows in a variety of application geometries including biomedical microdevices, anatomical structures and porous media

  19. Methods for determining enzymatic activity comprising heating and agitation of closed volumes

    Science.gov (United States)

    Thompson, David Neil; Henriksen, Emily DeCrescenzo; Reed, David William; Jensen, Jill Renee

    2016-03-15

    Methods for determining thermophilic enzymatic activity include heating a substrate solution in a plurality of closed volumes to a predetermined reaction temperature. Without opening the closed volumes, at least one enzyme is added, substantially simultaneously, to the closed volumes. At the predetermined reaction temperature, the closed volumes are agitated and then the activity of the at least one enzyme is determined. The methods are conducive for characterizing enzymes of high-temperature reactions, with insoluble substrates, with substrates and enzymes that do not readily intermix, and with low volumes of substrate and enzyme. Systems for characterizing the enzymes are also disclosed.

  20. Comparison of the accuracy of three angiographic methods for calculating left ventricular volume measurement

    International Nuclear Information System (INIS)

    Hu Lin; Cui Wei; Shi Hanwen; Tian Yingping; Wang Weigang; Feng Yanguang; Huang Xueyan; Liu Zhisheng

    2003-01-01

    Objective: To compare the relative accuracy of three methods measuring left ventricular volume by X-ray ventriculography: single plane area-length method, biplane area-length method, and single-plane Simpson's method. Methods: Left ventricular casts were obtained within 24 hours after death from 12 persons who died from non-cardiac causes. The true left ventricular cast volume was measured by water displacement. The calculated volume of the casts was obtained with 3 angiographic methods, i.e., single-plane area-length method, biplane area-length method, and single-plane Simpson's method. Results: The actual average volume of left ventricular casts was (61.17±26.49) ml. The left ventricular volume was averagely (97.50±35.56) ml with single plane area-length method, (90.51±36.33) ml with biplane area-length method, and (65.00± 23.63) ml with single-plane Simpson's method. The left ventricular volumes calculated with single-plane and biplane area-length method were significantly larger than that the actual volumes (P 0.05). The left ventricular volumes calculated with single-plane and biplane area-length method were significantly larger than those calculated with single-plane Simpson's method (P 0.05). The over-estimation of left ventricular volume by single plane area-length method (36.34±17.98) ml and biplane area-length method (29.34±15.59) ml was more obvious than that calculated by single-plane Simpson's method (3.83±8.48) ml. Linear regression analysis showed that there was close correlations between left ventricular volumes calculated with single plane area-length method, biplane area-length method, Simpson's method and the true volume (all r>0.98). Conclusion: Single-plane Simpson's method is more accurate than single plane area-length method and biplane area-length method for left ventricular volume measurement; however, both the single-plane and biplane area-length methods could be used in clinical practice, especially in those imaging modality

  1. Method and apparatus for probing relative volume fractions

    Science.gov (United States)

    Jandrasits, Walter G.; Kikta, Thomas J.

    1998-01-01

    A relative volume fraction probe particularly for use in a multiphase fluid system includes two parallel conductive paths defining therebetween a sample zone within the system. A generating unit generates time varying electrical signals which are inserted into one of the two parallel conductive paths. A time domain reflectometer receives the time varying electrical signals returned by the second of the two parallel conductive paths and, responsive thereto, outputs a curve of impedance versus distance. An analysis unit then calculates the area under the curve, subtracts the calculated area from an area produced when the sample zone consists entirely of material of a first fluid phase, and divides this calculated difference by the difference between an area produced when the sample zone consists entirely of material of the first fluid phase and an area produced when the sample zone consists entirely of material of a second fluid phase. The result is the volume fraction.

  2. Urban Run-off Volumes Dependency on Rainfall Measurement Method

    DEFF Research Database (Denmark)

    Pedersen, L.; Jensen, N. E.; Rasmussen, Michael R.

    2005-01-01

    Urban run-off is characterized with fast response since the large surface run-off in the catchments responds immediately to variations in the rainfall. Modeling such type of catchments is most often done with the input from very few rain gauges, but the large variation in rainfall over small areas...... resolutions and single gauge rainfall was fed to a MOUSE run-off model. The flow and total volume over the event is evaluated....

  3. New method of assigning uncertainty in volume calibration

    International Nuclear Information System (INIS)

    Lechner, J.A.; Reeve, C.P.; Spiegelman, C.H.

    1980-12-01

    This paper presents a practical statistical overview of the pressure-volume calibration curve for large nuclear materials processing tanks. It explains the appropriateness of applying splines (piecewise polynomials) to this curve, and it presents an overview of the associated statistical uncertainties. In order to implement these procedures, a practical and portable FORTRAN IV program is provided along with its users' manual. Finally, the recommended procedure is demonstrated on actual tank data collected by NBS

  4. Calculating the tumor volume of acoustic neuromas: comparison of ABC/2 formula with planimetry method.

    Science.gov (United States)

    Yu, Yi-Lin; Lee, Meei-Shyuan; Juan, Chun-Jung; Hueng, Dueng-Yuan

    2013-08-01

    The ABC/2 equation is commonly applied to measure the volume of intracranial hematoma. However, the precision of ABC/2 equation in estimating the tumor volume of acoustic neuromas is less addressed. The study is to evaluate the accuracy of the ABC/2 formula by comparing with planimetry method for estimating the tumor volumes. Thirty-two patients diagnosed with acoustic neuroma received contrast-enhanced magnetic resonance imaging of brain were recruited. The volume was calculated by the ABC/2 equation and planimetry method (defined as exact volume) at the same time. The 32 patients were divided into three groups by tumor volume to avoid volume-dependent overestimation (6 ml). The tumor volume by ABC/2 method was highly correlated to that calculated by planimetry method using linear regression analysis (R2=0.985). Pearson correlation coefficient (r=0.993, pABC/2 formula is an easy method in estimating the tumor volume of acoustic neuromas that is not inferior to planimetry method. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Monte Carlo Method with Heuristic Adjustment for Irregularly Shaped Food Product Volume Measurement

    Directory of Open Access Journals (Sweden)

    Joko Siswantoro

    2014-01-01

    Full Text Available Volume measurement plays an important role in the production and processing of food products. Various methods have been proposed to measure the volume of food products with irregular shapes based on 3D reconstruction. However, 3D reconstruction comes with a high-priced computational cost. Furthermore, some of the volume measurement methods based on 3D reconstruction have a low accuracy. Another method for measuring volume of objects uses Monte Carlo method. Monte Carlo method performs volume measurements using random points. Monte Carlo method only requires information regarding whether random points fall inside or outside an object and does not require a 3D reconstruction. This paper proposes volume measurement using a computer vision system for irregularly shaped food products without 3D reconstruction based on Monte Carlo method with heuristic adjustment. Five images of food product were captured using five cameras and processed to produce binary images. Monte Carlo integration with heuristic adjustment was performed to measure the volume based on the information extracted from binary images. The experimental results show that the proposed method provided high accuracy and precision compared to the water displacement method. In addition, the proposed method is more accurate and faster than the space carving method.

  6. Monte Carlo method with heuristic adjustment for irregularly shaped food product volume measurement.

    Science.gov (United States)

    Siswantoro, Joko; Prabuwono, Anton Satria; Abdullah, Azizi; Idrus, Bahari

    2014-01-01

    Volume measurement plays an important role in the production and processing of food products. Various methods have been proposed to measure the volume of food products with irregular shapes based on 3D reconstruction. However, 3D reconstruction comes with a high-priced computational cost. Furthermore, some of the volume measurement methods based on 3D reconstruction have a low accuracy. Another method for measuring volume of objects uses Monte Carlo method. Monte Carlo method performs volume measurements using random points. Monte Carlo method only requires information regarding whether random points fall inside or outside an object and does not require a 3D reconstruction. This paper proposes volume measurement using a computer vision system for irregularly shaped food products without 3D reconstruction based on Monte Carlo method with heuristic adjustment. Five images of food product were captured using five cameras and processed to produce binary images. Monte Carlo integration with heuristic adjustment was performed to measure the volume based on the information extracted from binary images. The experimental results show that the proposed method provided high accuracy and precision compared to the water displacement method. In addition, the proposed method is more accurate and faster than the space carving method.

  7. Supplier Portfolio Selection and Optimum Volume Allocation: A Knowledge Based Method

    NARCIS (Netherlands)

    Aziz, Romana; Aziz, R.; van Hillegersberg, Jos; Kersten, W.; Blecker, T.; Luthje, C.

    2010-01-01

    Selection of suppliers and allocation of optimum volumes to suppliers is a strategic business decision. This paper presents a decision support method for supplier selection and the optimal allocation of volumes in a supplier portfolio. The requirements for the method were gathered during a case

  8. Test work of sand compaction pile method on coal ash soil foundation. Sekitanbai jiban ni okeru sand compaction pile koho no shiken seko

    Energy Technology Data Exchange (ETDEWEB)

    Goto, K.; Maeda, S.; Shibata, T. (The Kansai Electric Power Co. Inc., Osaka (Japan))

    1992-01-25

    As an electric power supply source after the 1990 {prime}s, Nos. 5 and 6 units are additionally being constructed by Kansai Electric Power in its Himeji Power Station No.1 which is an exclusively LNG burning power station. The additional construction site of those units is of soil foundation reclaimed with coal ash which was used residual product in the existing No.1 through No.4 units. As a result of soil foundation survey, the coal ash layer and sand layer were known to be of material to be possibly liquidized at the time of earthquake. As measures against the liquidization, application was basically made of a sand compaction pile (SCP) method which is economical and abundant in record. However, that method was so short of record in the coal ash layer that its evaluation was difficult in soil reforming effect. Therefore, its applicability was evaluated by a work test on the site, which resulted in a confirmation that the coal ash as well as the sand can be sufficiently reformed by the SCP method. Started in September, 1991, the additional construction of Nos. 5 and 6 units in Himeji Power Station No.1 uses a 1.5m pitch SCP method to reform the soil foundation. 3 refs., 10 figs., 1 tab.

  9. Lung lesion doubling times: values and variability based on method of volume determination

    International Nuclear Information System (INIS)

    Eisenbud Quint, Leslie; Cheng, Joan; Schipper, Matthew; Chang, Andrew C.; Kalemkerian, Gregory

    2008-01-01

    Purpose: To determine doubling times (DTs) of lung lesions based on volumetric measurements from thin-section CT imaging. Methods: Previously untreated patients with ≥ two thin-section CT scans showing a focal lung lesion were identified. Lesion volumes were derived using direct volume measurements and volume calculations based on lesion area and diameter. Growth rates (GRs) were compared by tissue diagnosis and measurement technique. Results: 54 lesions were evaluated including 8 benign lesions, 10 metastases, 3 lymphomas, 15 adenocarcinomas, 11 squamous carcinomas, and 7 miscellaneous lung cancers. Using direct volume measurements, median DTs were 453, 111, 15, 181, 139 and 137 days, respectively. Lung cancer DTs ranged from 23-2239 days. There were no significant differences in GRs among the different lesion types. There was considerable variability among GRs using different volume determination methods. Conclusions: Lung cancer doubling times showed a substantial range, and different volume determination methods gave considerably different DTs

  10. A volume of fluid method based on multidimensional advection and spline interface reconstruction

    International Nuclear Information System (INIS)

    Lopez, J.; Hernandez, J.; Gomez, P.; Faura, F.

    2004-01-01

    A new volume of fluid method for tracking two-dimensional interfaces is presented. The method involves a multidimensional advection algorithm based on the use of edge-matched flux polygons to integrate the volume fraction evolution equation, and a spline-based reconstruction algorithm. The accuracy and efficiency of the proposed method are analyzed using different tests, and the results are compared with those obtained recently by other authors. Despite its simplicity, the proposed method represents a significant improvement, and compares favorably with other volume of fluid methods as regards the accuracy and efficiency of both the advection and reconstruction steps

  11. Finite elements volumes methods: applications to the Navier-Stokes equations and convergence results

    International Nuclear Information System (INIS)

    Emonot, P.

    1992-01-01

    In the first chapter are described the equations modeling incompressible fluid flow and a quick presentation of finite volumes method. The second chapter is an introduction to the finite elements volumes method. The box model is described and a method adapted to Navier-Stokes problems is proposed. The third chapter shows a fault analysis of the finite elements volumes method for the Laplacian problem and some examples in one, two, three dimensional calculations. The fourth chapter is an extension of the error analysis of the method for the Navier-Stokes problem

  12. Buckling of Bucket Foundations

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2012-01-01

    In this paper, the risk of structural buckling during installation of large-diameter bucket foundations is addressed using numerical methods. Imperfect geometries are introduced based on the pre-buckling mode shapes from a linear Eigenvalue buckling analysis. Various imperfect geometries are intr...

  13. Optimization Foundations and Applications

    CERN Document Server

    Miller, H Ronald

    2011-01-01

    A thorough and highly accessible resource for analysts in a broad range of social sciences. Optimization: Foundations and Applications presents a series of approaches to the challenges faced by analysts who must find the best way to accomplish particular objectives, usually with the added complication of constraints on the available choices. Award-winning educator Ronald E. Miller provides detailed coverage of both classical, calculus-based approaches and newer, computer-based iterative methods. Dr. Miller lays a solid foundation for both linear and nonlinear models and quickly moves on to dis

  14. Foundations of predictive analytics

    CERN Document Server

    Wu, James

    2012-01-01

    Drawing on the authors' two decades of experience in applied modeling and data mining, Foundations of Predictive Analytics presents the fundamental background required for analyzing data and building models for many practical applications, such as consumer behavior modeling, risk and marketing analytics, and other areas. It also discusses a variety of practical topics that are frequently missing from similar texts. The book begins with the statistical and linear algebra/matrix foundation of modeling methods, from distributions to cumulant and copula functions to Cornish--Fisher expansion and o

  15. Protection Parameters against the Cracks by the Method of Volume Compensation Dam

    Directory of Open Access Journals (Sweden)

    Bulatov Georgiy

    2016-01-01

    Full Text Available This article provides estimates the parameters of protection from cracking dam due to volume compensation method. This article discusses the method of compensation dam volume. This method allows calculating the settings of security causing cracks the dam. Presents graphs of horizontal deformations of elongation calculated surface along the length of the construction and in time. Showing horizontal stress distribution diagram in the ground around the pile in plan and in section. Given all the necessary formulas for the method of compensation of the dam volume.

  16. Numerical study of the stress-strain state of reinforced plate on an elastic foundation by the Bubnov-Galerkin method

    Science.gov (United States)

    Beskopylny, Alexey; Kadomtseva, Elena; Strelnikov, Grigory

    2017-10-01

    The stress-strain state of a rectangular slab resting on an elastic foundation is considered. The slab material is isotropic. The slab has stiffening ribs that directed parallel to both sides of the plate. Solving equations are obtained for determining the deflection for various mechanical and geometric characteristics of the stiffening ribs which are parallel to different sides of the plate, having different rigidity for bending and torsion. The calculation scheme assumes an orthotropic slab having different cylindrical stiffness in two mutually perpendicular directions parallel to the reinforcing ribs. An elastic foundation is adopted by Winkler model. To determine the deflection the Bubnov-Galerkin method is used. The deflection is taken in the form of an expansion in a series with unknown coefficients by special polynomials, which are a combination of Legendre polynomials.

  17. Feasibility of the left ventricular volume measurement by acoustic quantification method. Comparison with ultrafast computed tomography

    International Nuclear Information System (INIS)

    Tomimoto, Shigehiro; Nakatani, Satoshi; Tanaka, Norio; Uematsu, Masaaki; Beppu, Shintaro; Nagata, Seiki; Hamada, Seiki; Takamiya, Makoto; Miyatake, Kunio

    1995-01-01

    Acoustic quantification (AQ: the real-time automated boundary detection system) allows instantaneous measurement of cardiac chamber volumes. The feasibility of this method was evaluated by comparing the left ventricular (LV) volumes obtained with AQ to those derived from ultrafast computed tomography (UFCT), which enables accurate measurements of LV volumes even in the presence of LV asynergy, in 23 patients (8 with ischemic heart disease, 5 with cardiomyopathy, 3 with valvular heart disease). Both LV end-diastolic and end-systolic volumes obtained with the AQ method were in good agreement with those obtained with UFCT (y=1.04χ-16.9, r=0.95; y=0.87χ+15.7, r=0.91; respectively). AQ was reliable even in the presence of LV asynergy. Interobserver variability for the AQ measurement was 10.2%. AQ provides a new, clinically useful method for real-time accurate estimation of the left ventricular volume. (author)

  18. Feasibility of the left ventricular volume measurement by acoustic quantification method. Comparison with ultrafast computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Tomimoto, Shigehiro; Nakatani, Satoshi; Tanaka, Norio; Uematsu, Masaaki; Beppu, Shintaro; Nagata, Seiki; Hamada, Seiki; Takamiya, Makoto; Miyatake, Kunio [National Cardiovascular Center, Suita, Osaka (Japan)

    1995-01-01

    Acoustic quantification (AQ: the real-time automated boundary detection system) allows instantaneous measurement of cardiac chamber volumes. The feasibility of this method was evaluated by comparing the left ventricular (LV) volumes obtained with AQ to those derived from ultrafast computed tomography (UFCT), which enables accurate measurements of LV volumes even in the presence of LV asynergy, in 23 patients (8 with ischemic heart disease, 5 with cardiomyopathy, 3 with valvular heart disease). Both LV end-diastolic and end-systolic volumes obtained with the AQ method were in good agreement with those obtained with UFCT (y=1.04{chi}-16.9, r=0.95; y=0.87{chi}+15.7, r=0.91; respectively). AQ was reliable even in the presence of LV asynergy. Interobserver variability for the AQ measurement was 10.2%. AQ provides a new, clinically useful method for real-time accurate estimation of the left ventricular volume. (author).

  19. Quantification and variability in colonic volume with a novel magnetic resonance imaging method

    DEFF Research Database (Denmark)

    Nilsson, M; Sandberg, Thomas Holm; Poulsen, Jakob Lykke

    2015-01-01

    Background: Segmental distribution of colorectal volume is relevant in a number of diseases, but clinical and experimental use demands robust reliability and validity. Using a novel semi-automatic magnetic resonance imaging-based technique, the aims of this study were to describe: (i) inter......-individual and intra-individual variability of segmental colorectal volumes between two observations in healthy subjects and (ii) the change in segmental colorectal volume distribution before and after defecation. Methods: The inter-individual and intra-individual variability of four colorectal volumes (cecum...... (p = 0.02). Conclusions & Inferences: Imaging of segmental colorectal volume, morphology, and fecal accumulation is advantageous to conventional methods in its low variability, high spatial resolution, and its absence of contrast-enhancing agents and irradiation. Hence, the method is suitable...

  20. Variation in Measurements of Transtibial Stump Model Volume A Comparison of Five Methods

    NARCIS (Netherlands)

    Bolt, A.; de Boer-Wilzing, V. G.; Geertzen, J. H. B.; Emmelot, C. H.; Baars, E. C. T.; Dijkstra, P. U.

    Objective: To determine the right moment for fitting the first prosthesis, it is necessary to know when the volume of the stump has stabilized. The aim of this study is to analyze variation in measurements of transtibial stump model volumes using the water immersion method, the Design TT system, the

  1. Variant of a volume-of-fluid method for surface tension-dominant two ...

    Indian Academy of Sciences (India)

    2013-12-27

    Dec 27, 2013 ... face tension-dominant two-phase flows are explained. ... for one particular fluid inside a cell as its material volume divided by the total ... the reconstructed interface and the velocity field, and the final part ..... Welch S W J and Wilson J 2000 A volume of fluid based method for fluid flows with phase change. J.

  2. Critical length sampling: a method to estimate the volume of downed coarse woody debris

    Science.gov (United States)

    G& #246; ran St& #229; hl; Jeffrey H. Gove; Michael S. Williams; Mark J. Ducey

    2010-01-01

    In this paper, critical length sampling for estimating the volume of downed coarse woody debris is presented. Using this method, the volume of downed wood in a stand can be estimated by summing the critical lengths of down logs included in a sample obtained using a relascope or wedge prism; typically, the instrument should be tilted 90° from its usual...

  3. A new method to estimate the atomic volume of ternary intermetallic compounds

    International Nuclear Information System (INIS)

    Pani, M.; Merlo, F.

    2011-01-01

    The atomic volume of an A x B y C z ternary intermetallic compound can be calculated starting from volumes of some proper A-B, A-C and B-C binary phases. The three methods by Colinet, Muggianu and Kohler, originally used to estimate thermodynamic quantities, and a new method here proposed, were tested to derive volume data in eight systems containing 91 ternary phases with the known structure. The comparison between experimental and calculated volume values shows the best agreement both for the Kohler method and for the new proposed procedure. -- Graphical abstract: Synopsys: the volume of a ternary intermetallic compound can be calculated starting from volumes of some binary phases, selected by the methods of Colinet, Muggianu, Kohler and a new method proposed here. The so obtained values are compared with the experimental ones for eight ternary systems. Display Omitted Research highlights: → The application of some thermodinamic methods to a crystallochemical problem. → The prevision of the average atomic volume of ternary intermetallic phases. → The proposal of a new procedure to select the proper starting set of binary phases.

  4. A Monte Carlo method and finite volume method coupled optical simulation method for parabolic trough solar collectors

    International Nuclear Information System (INIS)

    Liang, Hongbo; Fan, Man; You, Shijun; Zheng, Wandong; Zhang, Huan; Ye, Tianzhen; Zheng, Xuejing

    2017-01-01

    Highlights: •Four optical models for parabolic trough solar collectors were compared in detail. •Characteristics of Monte Carlo Method and Finite Volume Method were discussed. •A novel method was presented combining advantages of different models. •The method was suited to optical analysis of collectors with different geometries. •A new kind of cavity receiver was simulated depending on the novel method. -- Abstract: The PTC (parabolic trough solar collector) is widely used for space heating, heat-driven refrigeration, solar power, etc. The concentrated solar radiation is the only energy source for a PTC, thus its optical performance significantly affects the collector efficiency. In this study, four different optical models were constructed, validated and compared in detail. On this basis, a novel coupled method was presented by combining advantages of these models, which was suited to carry out a mass of optical simulations of collectors with different geometrical parameters rapidly and accurately. Based on these simulation results, the optimal configuration of a collector with highest efficiency can be determined. Thus, this method was useful for collector optimization and design. In the four models, MCM (Monte Carlo Method) and FVM (Finite Volume Method) were used to initialize photons distribution, as well as CPEM (Change Photon Energy Method) and MCM were adopted to describe the process of reflecting, transmitting and absorbing. For simulating reflection, transmission and absorption, CPEM was more efficient than MCM, so it was utilized in the coupled method. For photons distribution initialization, FVM saved running time and computation effort, whereas it needed suitable grid configuration. MCM only required a total number of rays for simulation, whereas it needed higher computing cost and its results fluctuated in multiple runs. In the novel coupled method, the grid configuration for FVM was optimized according to the “true values” from MCM of

  5. Incineration method for volume reduction and disposal of transuranic waste

    International Nuclear Information System (INIS)

    Borham, B.M.

    1985-01-01

    The Process Experimental Pilot Plant (PREPP) at Idaho National Engineering Laboratory (INEL) is designed to process 7 TPD of transuranic (TRU) waste producing 8.5 TPD of cemented waste and 4100 ACFM of combustion gases with a volume reduction of up to 17:1. The waste and its container are shredded then fed to a rotary kiln heated to 1700 0 F, then cooled and classified by a trommel screen. The fine portion is mixed with a cement grout which is placed with the coarse portion in steel drums for disposal at the Waste Isolation Pilot Plant (WIPP). The kiln off-gas is reheated to 2000 0 F to destroy any remaining hydrocarbons and toxic volatiles. The gases are cooled and passed in a venturi scrubber to remove particulates and corrosive gases. The venturi off-gas is passed through a mist eliminator and is reheated to 50 0 F above the dew point prior to passing through a High Efficiency Particulate Air (HEPA) filter. The scrub solution is concentrated to 25% solids by an inertial filter. The sludge containing the combustion chemical contaminants is encapsulated with the residue of the incinerated waste

  6. Volume Equalization Method for Land Grading Design: Uniform ...

    African Journals Online (AJOL)

    muğla üniversitesi

    2011-05-23

    May 23, 2011 ... *Corresponding author. E-mail: ... Land grading has been in practice for a long time, but land-grading ... method was based on least-squares theory and he showed its ... Srinisava (1996) developed a nonlinear optimization.

  7. Development of production methods of volume source by the resinous solution which has hardening

    CERN Document Server

    Motoki, R

    2002-01-01

    Volume sources is used for standard sources by radioactive measurement using Ge semiconductor detector of environmental sample, e.g. water, soil and etc. that require large volume. The commercial volume source used in measurement of the water sample is made of agar-agar, and that used in measurement of the soil sample is made of alumina powder. When the plastic receptacles of this two kinds of volume sources were damaged, the leakage contents cause contamination. Moreover, if hermetically sealing performance of volume source made of agar-agar fell, volume decrease due to an evaporation off moisture gives an error to radioactive measurement. Therefore, we developed the two type methods using unsaturated polyester resin, vinilester resin, their hardening agent and acrylicresin. The first type is due to dispersing the hydrochloric acid solution included the radioisotopes uniformly in each resin and hardening the resin. The second is due to dispersing the alumina powder absorbed the radioisotopes in each resin an...

  8. A finite volume method for cylindrical heat conduction problems based on local analytical solution

    KAUST Repository

    Li, Wang

    2012-10-01

    A new finite volume method for cylindrical heat conduction problems based on local analytical solution is proposed in this paper with detailed derivation. The calculation results of this new method are compared with the traditional second-order finite volume method. The newly proposed method is more accurate than conventional ones, even though the discretized expression of this proposed method is slightly more complex than the second-order central finite volume method, making it cost more calculation time on the same grids. Numerical result shows that the total CPU time of the new method is significantly less than conventional methods for achieving the same level of accuracy. © 2012 Elsevier Ltd. All rights reserved.

  9. A finite volume method for cylindrical heat conduction problems based on local analytical solution

    KAUST Repository

    Li, Wang; Yu, Bo; Wang, Xinran; Wang, Peng; Sun, Shuyu

    2012-01-01

    A new finite volume method for cylindrical heat conduction problems based on local analytical solution is proposed in this paper with detailed derivation. The calculation results of this new method are compared with the traditional second-order finite volume method. The newly proposed method is more accurate than conventional ones, even though the discretized expression of this proposed method is slightly more complex than the second-order central finite volume method, making it cost more calculation time on the same grids. Numerical result shows that the total CPU time of the new method is significantly less than conventional methods for achieving the same level of accuracy. © 2012 Elsevier Ltd. All rights reserved.

  10. Behavior Modeling -- Foundations and Applications

    DEFF Research Database (Denmark)

    This book constitutes revised selected papers from the six International Workshops on Behavior Modelling - Foundations and Applications, BM-FA, which took place annually between 2009 and 2014. The 9 papers presented in this volume were carefully reviewed and selected from a total of 58 papers...

  11. ABC/2 Method Does not Accurately Predict Cerebral Arteriovenous Malformation Volume.

    Science.gov (United States)

    Roark, Christopher; Vadlamudi, Venu; Chaudhary, Neeraj; Gemmete, Joseph J; Seinfeld, Joshua; Thompson, B Gregory; Pandey, Aditya S

    2018-02-01

    Stereotactic radiosurgery (SRS) is a treatment option for cerebral arteriovenous malformations (AVMs) to prevent intracranial hemorrhage. The decision to proceed with SRS is usually based on calculated nidal volume. Physicians commonly use the ABC/2 formula, based on digital subtraction angiography (DSA), when counseling patients for SRS. To determine whether AVM volume calculated using the ABC/2 method on DSA is accurate when compared to the exact volume calculated from thin-cut axial sections used for SRS planning. Retrospective search of neurovascular database to identify AVMs treated with SRS from 1995 to 2015. Maximum nidal diameters in orthogonal planes on DSA images were recorded to determine volume using ABC/2 formula. Nidal target volume was extracted from operative reports of SRS. Volumes were then compared using descriptive statistics and paired t-tests. Ninety intracranial AVMs were identified. Median volume was 4.96 cm3 [interquartile range (IQR) 1.79-8.85] with SRS planning methods and 6.07 cm3 (IQR 1.3-13.6) with ABC/2 methodology. Moderate correlation was seen between SRS and ABC/2 (r = 0.662; P ABC/2 (t = -3.2; P = .002). When AVMs were dichotomized based on ABC/2 volume, significant differences remained (t = 3.1, P = .003 for ABC/2 volume ABC/2 volume > 7 cm3). The ABC/2 method overestimates cerebral AVM volume when compared to volumetric analysis from SRS planning software. For AVMs > 7 cm3, the overestimation is even greater. SRS planning techniques were also significantly different than values derived from equations for cones and cylinders. Copyright © 2017 by the Congress of Neurological Surgeons

  12. A New Volume-Of-Fluid Method in Openfoam

    DEFF Research Database (Denmark)

    Pedersen, Johan Rønby; Eltard-Larsen, Bjarke; Bredmose, Henrik

    methods have become quiteadvanced and accurate on structured meshes, there is still room for improvement when it comesto unstructured meshes of the type needed to simulate ows in and around complex geometricstructures. We have recently developed a new geometric VOF algorithm called isoAdvector forgeneral...... limited interface compression, with the new isoAd-vector method. Our test case is a steady 2D stream function wave propagating in a periodicdomain. Based on a series of simulations with different numerical settings, we conclude that theintroduction of isoAdvector has a significant effect on wave...

  13. The finite volume method in computational fluid dynamics an advanced introduction with OpenFOAM and Matlab

    CERN Document Server

    Moukalled, F; Darwish, M

    2016-01-01

    This textbook explores both the theoretical foundation of the Finite Volume Method (FVM) and its applications in Computational Fluid Dynamics (CFD). Readers will discover a thorough explanation of the FVM numerics and algorithms used for the simulation of incompressible and compressible fluid flows, along with a detailed examination of the components needed for the development of a collocated unstructured pressure-based CFD solver. Two particular CFD codes are explored. The first is uFVM, a three-dimensional unstructured pressure-based finite volume academic CFD code, implemented within Matlab. The second is OpenFOAM®, an open source framework used in the development of a range of CFD programs for the simulation of industrial scale flow problems. With over 220 figures, numerous examples and more than one hundred exercise on FVM numerics, programming, and applications, this textbook is suitable for use in an introductory course on the FVM, in an advanced course on numerics, and as a reference for CFD programm...

  14. Estimation method for volumes of hot spots created by heavy ions

    International Nuclear Information System (INIS)

    Kanno, Ikuo; Kanazawa, Satoshi; Kajii, Yuji

    1999-01-01

    As a ratio of volumes of hot spots to cones, which have the same lengths and bottom radii with the ones of hot spots, a simple and convenient method for estimating the volumes of hot spots is described. This calculation method is useful for the study of damage producing mechanism in hot spots, and is also convenient for the estimation of the electron-hole densities in plasma columns created by heavy ions in semiconductor detectors. (author)

  15. Simple method for the generation of multiple homogeneous field volumes inside the bore of superconducting magnets.

    Science.gov (United States)

    Chou, Ching-Yu; Ferrage, Fabien; Aubert, Guy; Sakellariou, Dimitris

    2015-07-17

    Standard Magnetic Resonance magnets produce a single homogeneous field volume, where the analysis is performed. Nonetheless, several modern applications could benefit from the generation of multiple homogeneous field volumes along the axis and inside the bore of the magnet. In this communication, we propose a straightforward method using a combination of ring structures of permanent magnets in order to cancel the gradient of the stray field in a series of distinct volumes. These concepts were demonstrated numerically on an experimentally measured magnetic field profile. We discuss advantages and limitations of our method and present the key steps required for an experimental validation.

  16. Finite Volume Method for Pricing European Call Option with Regime-switching Volatility

    Science.gov (United States)

    Lista Tauryawati, Mey; Imron, Chairul; Putri, Endah RM

    2018-03-01

    In this paper, we present a finite volume method for pricing European call option using Black-Scholes equation with regime-switching volatility. In the first step, we formulate the Black-Scholes equations with regime-switching volatility. we use a finite volume method based on fitted finite volume with spatial discretization and an implicit time stepping technique for the case. We show that the regime-switching scheme can revert to the non-switching Black Scholes equation, both in theoretical evidence and numerical simulations.

  17. Errors of the backextrapolation method in determination of the blood volume

    Science.gov (United States)

    Schröder, T.; Rösler, U.; Frerichs, I.; Hahn, G.; Ennker, J.; Hellige, G.

    1999-01-01

    Backextrapolation is an empirical method to calculate the central volume of distribution (for example the blood volume). It is based on the compartment model, which says that after an injection the substance is distributed instantaneously in the central volume with no time delay. The occurrence of recirculation is not taken into account. The change of concentration with time of indocyanine green (ICG) was observed in an in vitro model, in which the volume was recirculating in 60 s and the clearance of the ICG could be varied. It was found that the higher the elimination of ICG, the higher was the error of the backextrapolation method. The theoretical consideration of Schröder et al ( Biomed. Tech. 42 (1997) 7-11) was proved. If the injected substance is eliminated somewhere in the body (i.e. not by radioactive decay), the backextrapolation method produces large errors.

  18. Fiscal 1999 survey report. Survey of long-term strategy for energy technology: Volume 1 (Survey of foundation for strategy formulation for industrial technologies - strategy for environmental foundation buildup); 1999 nendo choki energy gijutsu senryaku nado ni kansuru chosa hokokusho. 1. Sangyo gijutsu senryaku sakutei kiban chosa (kankyo kiban seibi senryaku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Japan has to prepare itself to behave accurately, and to stay technologically competitive, in the severe competition age to come in which it will fail to find leaders to follow. To fulfill this goal, Japan has to collect sufficient information and analyze it relative to the current state and future prospect of industrial technologies in Japan and overseas and various factors that will influence them, and to develop industrial technology related policies based firmly on scientific and theoretical foundations to be established using the thus-acquired knowledge. Under the circumstances, a survey is conducted of innovative, technological foundations, such as industrial technology related efforts in and out of Japan. The report consists of two volumes that cover what are described below. For the survey of technology related policies pursued in various countries abroad, literature and the like are investigated concerning technology related measures, budgets, and decision making processes in America, Britain, Germany, France, and the European Union, and the results are compiled so that their systems may be compared with each other. In the survey of Japan's technology related innovative systems, case studies are made about commodities over which Japan is relatively high in competitive power. Specifically, commodities manufactured by Japan's businesses and occupying 75% or more of the global share are investigated. (NEDO)

  19. Fiscal 1999 survey report. Survey of long-term strategy for energy technology: Volume 1 (Survey of foundation for strategy formulation for industrial technologies - strategy for environmental foundation buildup); 1999 nendo choki energy gijutsu senryaku nado ni kansuru chosa hokokusho. 1. Sangyo gijutsu senryaku sakutei kiban chosa (kankyo kiban seibi senryaku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Japan has to prepare itself to behave accurately, and to stay technologically competitive, in the severe competition age to come in which it will fail to find leaders to follow. To fulfill this goal, Japan has to collect sufficient information and analyze it relative to the current state and future prospect of industrial technologies in Japan and overseas and various factors that will influence them, and to develop industrial technology related policies based firmly on scientific and theoretical foundations to be established using the thus-acquired knowledge. Under the circumstances, a survey is conducted of innovative, technological foundations, such as industrial technology related efforts in and out of Japan. The report consists of two volumes that cover what are described below. For the survey of technology related policies pursued in various countries abroad, literature and the like are investigated concerning technology related measures, budgets, and decision making processes in America, Britain, Germany, France, and the European Union, and the results are compiled so that their systems may be compared with each other. In the survey of Japan's technology related innovative systems, case studies are made about commodities over which Japan is relatively high in competitive power. Specifically, commodities manufactured by Japan's businesses and occupying 75% or more of the global share are investigated. (NEDO)

  20. Method of monitoring volume activity of natural radioactive aerosol

    International Nuclear Information System (INIS)

    Dvorak, V.

    1980-01-01

    The method of monitoring radioactivity of a aerosol trapped, eg., with a filter is based on counting quasi-coincidences of the RaC-RaC' and ThC-ThC' decay. The first electronic unit counts quasi-coincidences at a time interval proportional to the ThC' half-life while the second electronic unit counts quasi-coincidences at a time interval proportional to the RaC' half-life, reduced by the time interval of the first electronic unit. The quasi-coincidences are evaluated of the RaC-RaC' decay independently of the ThC-ThC' quasi-coincidences and the decay products of the trapped radon and thoron gases are thus offset separately. (J.P.)

  1. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 4, Organic methods

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    This interim notice covers the following: extractable organic halides in solids, total organic halides, analysis by gas chromatography/Fourier transform-infrared spectroscopy, hexadecane extracts for volatile organic compounds, GC/MS analysis of VOCs, GC/MS analysis of methanol extracts of cryogenic vapor samples, screening of semivolatile organic extracts, GPC cleanup for semivolatiles, sample preparation for GC/MS for semi-VOCs, analysis for pesticides/PCBs by GC with electron capture detection, sample preparation for pesticides/PCBs in water and soil sediment, report preparation, Florisil column cleanup for pesticide/PCBs, silica gel and acid-base partition cleanup of samples for semi-VOCs, concentrate acid wash cleanup, carbon determination in solids using Coulometrics` CO{sub 2} coulometer, determination of total carbon/total organic carbon/total inorganic carbon in radioactive liquids/soils/sludges by hot persulfate method, analysis of solids for carbonates using Coulometrics` Model 5011 coulometer, and soxhlet extraction.

  2. Calculating regional tissue volume for hyperthermic isolated limb perfusion: Four methods compared.

    Science.gov (United States)

    Cecchin, D; Negri, A; Frigo, A C; Bui, F; Zucchetta, P; Bodanza, V; Gregianin, M; Campana, L G; Rossi, C R; Rastrelli, M

    2016-12-01

    Hyperthermic isolated limb perfusion (HILP) can be performed as an alternative to amputation for soft tissue sarcomas and melanomas of the extremities. Melphalan and tumor necrosis factor-alpha are used at a dosage that depends on the volume of the limb. Regional tissue volume is traditionally measured for the purposes of HILP using water displacement volumetry (WDV). Although this technique is considered the gold standard, it is time-consuming and complicated to implement, especially in obese and elderly patients. The aim of the present study was to compare the different methods described in the literature for calculating regional tissue volume in the HILP setting, and to validate an open source software. We reviewed the charts of 22 patients (11 males and 11 females) who had non-disseminated melanoma with in-transit metastases or sarcoma of the lower limb. We calculated the volume of the limb using four different methods: WDV, tape measurements and segmentation of computed tomography images using Osirix and Oncentra Masterplan softwares. The overall comparison provided a concordance correlation coefficient (CCC) of 0.92 for the calculations of whole limb volume. In particular, when Osirix was compared with Oncentra (validated for volume measures and used in radiotherapy), the concordance was near-perfect for the calculation of the whole limb volume (CCC = 0.99). With methods based on CT the user can choose a reliable plane for segmentation purposes. CT-based methods also provides the opportunity to separate the whole limb volume into defined tissue volumes (cortical bone, fat and water). Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Mesothelioma Applied Research Foundation

    Science.gov (United States)

    ... Foundation Experts Can Answer Your Questions! The Mesothelioma Applied Research Foundation's team of experts is available to answer ... a law firm. Read more about the Mesothelioma Applied Research Foundation . TO GET HELP CALL: (877) End-Meso ...

  4. Comparative methods for quantifying thyroid volume using planar imaging and SPECT

    International Nuclear Information System (INIS)

    Zaidi, H.

    1996-01-01

    Thyroid volume determination using planar imaging is a procedure often performed in routine nuclear medicine, but is hampered by several physical difficulties, in particular by structures which overlie or underlie the organ of interest. SPECT enables improved accuracy over planar imaging in the determination of the volume since it is derived from the 3-D data rather than from a 2-D projection with a certain geometric assumption regarding the thyroid configuration. By using the phantoms of known volume, it was possible to estimate the accuracy of 3 different methods of determining thyroid volume from planar imaging used in clinical routine. The experimental results demonstrate that compared with conventional scintigraphy, thyroid phantom volumes were most accurately determined with SPECT when attenuation and scatter corrections are performed which allows accurate radiation dosimetry in humans without the need for assumptions on organ size or concentrations. Poster 181. (author)

  5. Design of a micro-irrigation system based on the control volume method

    Directory of Open Access Journals (Sweden)

    Chasseriaux G.

    2006-01-01

    Full Text Available A micro-irrigation system design based on control volume method using the back step procedure is presented in this study. The proposed numerical method is simple and consists of delimiting an elementary volume of the lateral equipped with an emitter, called « control volume » on which the conservation equations of the fl uid hydrodynamicʼs are applied. Control volume method is an iterative method to calculate velocity and pressure step by step throughout the micro-irrigation network based on an assumed pressure at the end of the line. A simple microcomputer program was used for the calculation and the convergence was very fast. When the average water requirement of plants was estimated, it is easy to choose the sum of the average emitter discharge as the total average fl ow rate of the network. The design consists of exploring an economical and effi cient network to deliver uniformly the input fl ow rate for all emitters. This program permitted the design of a large complex network of thousands of emitters very quickly. Three subroutine programs calculate velocity and pressure at a lateral pipe and submain pipe. The control volume method has already been tested for lateral design, the results from which were validated by other methods as fi nite element method, so it permits to determine the optimal design for such micro-irrigation network

  6. Scintigraphic method for evaluating reductions in local blood volumes in human extremities

    DEFF Research Database (Denmark)

    Blønd, L; Madsen, Jan Lysgård

    2000-01-01

    in the experiment. Evaluation of one versus two scintigraphic projections, trials for assessment of the reproducibility, a comparison of the scintigraphic method with a water-plethysmographic method and registration of the fractional reduction in blood volume caused by exsanguination as a result of simple elevation......% in the lower limb experiment and 6% in the upper limb experiment. We found a significant relation (r = 0.42, p = 0.018) between the results obtained by the scintigraphic method and the plethysmographic method. In fractions, a mean reduction in blood volume of 0.49+0.14 (2 SD) was found after 1 min of elevation......We introduce a new method for evaluating reductions in local blood volumes in extremities, based on the combined use of autologue injection of 99mTc-radiolabelled erythrocytes and clamping of the limb blood flow by the use of a tourniquet. Twenty-two healthy male volunteers participated...

  7. Efficient 3D Volume Reconstruction from a Point Cloud Using a Phase-Field Method

    Directory of Open Access Journals (Sweden)

    Darae Jeong

    2018-01-01

    Full Text Available We propose an explicit hybrid numerical method for the efficient 3D volume reconstruction from unorganized point clouds using a phase-field method. The proposed three-dimensional volume reconstruction algorithm is based on the 3D binary image segmentation method. First, we define a narrow band domain embedding the unorganized point cloud and an edge indicating function. Second, we define a good initial phase-field function which speeds up the computation significantly. Third, we use a recently developed explicit hybrid numerical method for solving the three-dimensional image segmentation model to obtain efficient volume reconstruction from point cloud data. In order to demonstrate the practical applicability of the proposed method, we perform various numerical experiments.

  8. Nondestructive Determination of Reinforcement Volume Fractions in Particulate Composites : Ultrasonic Method

    International Nuclear Information System (INIS)

    Jeong, Hyun Jo

    1998-01-01

    A nondestructive ultrasonic technique is presented for estimating the reinforcement volume fractions of particulate composites. The proposed technique employs a theoretical model which accounts for composite microstructures, together with a measurement of ultrasonic velocity to determine the reinforcement volume fractions. The approach is used for a wide range of SiC particulate reinforced Al matrix (SiC p /AI) composites. The method is considered to be reliable in determining the reinforcement volume fractions. The technique could be adopted in a production unit for the quality assessment of the metal matrix particulate composite extrusions

  9. Impedance ratio method for urine conductivity-invariant estimation of bladder volume

    Directory of Open Access Journals (Sweden)

    Thomas Schlebusch

    2014-09-01

    Full Text Available Non-invasive estimation of bladder volume could help patients with impaired bladder volume sensation to determine the right moment for catheterisation. Continuous, non-invasive impedance measurement is a promising technology in this scenario, although influences of body posture and unknown urine conductivity limit wide clinical use today. We studied impedance changes related to bladder volume by simulation, in-vitro and in-vivo measurements with pigs. In this work, we present a method to reduce the influence of urine conductivity to cystovolumetry and bring bioimpedance cystovolumetry closer to a clinical application.

  10. Effect of Water Volume and Biogas Volumetric Flowrate in Biogas Purification Through Water Scrubbing Method

    Directory of Open Access Journals (Sweden)

    Hendry Sakke Tira

    2016-05-01

    Full Text Available Energy supply is a crucial issue in the world in the last few years. The increase in energy demand caused by population growth and resource depletion of world oil reserves provides determination to produce and to use renewable energies. One of the them is biogas. However, until now the use of biogas has not yet been maximized because of its poor purity. According to the above problem, the research has been carried out using the method of water absorption. Under this method it is expected that the rural community is able to apply it. Therefore, their economy and productivity can be increased. This study includes variations of absorbing water volume (V and input biogas volume flow rate (Q. Raw biogas which is flowed into the absorbent will be analyzed according to the determined absorbing water volume and input biogas volume rate. Improvement on biogas composition through the biogas purification method was obtained. The level of CO2 and H2S was reduced significantly specifically in the early minutes of purification process. On the other hand, the level of CH4 was increased improving the quality of raw biogas. However, by the time of biogas purification the composition of purified biogas was nearly similar to the raw biogas. The main reason for this result was an increasing in pH of absorbent. It was shown that higher water volume and slower biogas volume rate obtained better results in reducing the CO2 and H2S and increasing CH4 compared to those of lower water volume and higher biogas volume rate respectively. The purification method has a good promising in improving the quality of raw biogas and has advantages as it is cheap and easy to be operated.

  11. Effect of Water Volume and Biogas Volumetric Flowrate in Biogas Purification Through Water Scrubbing Method

    Directory of Open Access Journals (Sweden)

    Hendry Sakke Tira

    2014-10-01

    Full Text Available Energy supply is a crucial issue in the world in the last few years. The increase in energy demand caused by population growth and resource depletion of world oil reserves provides determination to produce and to use renewable energies. One of the them is biogas. However, until now the use of biogas has not yet been maximized because of its poor purity. According to the above problem, the research has been carried out using the method of water absorption. Under this method it is expected that the rural community is able to apply it. Therefore, their economy and productivity can be increased. This study includes variations of absorbing water volume (V and input biogas volume flow rate (Q. Raw biogas which is flowed into the absorbent will be analyzed according to the determined absorbing water volume and input biogas volume rate. Improvement on biogas composition through the biogas purification method was obtained. The level of CO2 and H2S was reduced significantly specifically in the early minutes of purification process. On the other hand, the level of CH4 was increased improving the quality of raw biogas. However, by the time of biogas purification the composition of purified biogas was nearly similar to the raw biogas. The main reason for this result was an increasing in pH of absorbent. It was shown that higher water volume and slower biogas volume rate obtained better results in reducing the CO2 and H2S and increasing CH4 compared to those of lower water volume and higher biogas volume rate respectively. The purification method has a good promising in improving the quality of raw biogas and has advantages as it is cheap and easy to be operated.

  12. Fast multiview three-dimensional reconstruction method using cost volume filtering

    Science.gov (United States)

    Lee, Seung Joo; Park, Min Ki; Jang, In Yeop; Lee, Kwan H.

    2014-03-01

    As the number of customers who want to record three-dimensional (3-D) information using a mobile electronic device increases, it becomes more and more important to develop a method which quickly reconstructs a 3-D model from multiview images. A fast multiview-based 3-D reconstruction method is presented, which is suitable for the mobile environment by constructing a cost volume of the 3-D height field. This method consists of two steps: the construction of a reliable base surface and the recovery of shape details. In each step, the cost volume is constructed using photoconsistency and then it is filtered according to the multiscale. The multiscale-based cost volume filtering allows the 3-D reconstruction to maintain the overall shape and to preserve the shape details. We demonstrate the strength of the proposed method in terms of computation time, accuracy, and unconstrained acquisition environment.

  13. Method of phase-Doppler anemometry free from the measurement-volume effect.

    Science.gov (United States)

    Qiu, H; Hsu, C T

    1999-05-01

    A novel method is developed to improve the accuracy of particle sizing in laser phase-Doppler anemometry (PDA). In this method the vector sum of refractive and reflective rays is taken into consideration in describing a dual-mechanism-scattering model caused by a nonuniformly illuminated PDA measurement volume. The constraint of the single-mechanism-scattering model in the conventional PDA is removed. As a result the error caused by the measurement-volume effect, which consists of a Gaussian-beam defect and a slit effect, can be eliminated. This new method can be easily implemented with minimal modification of the conventional PDA system. The results of simulation based on the generalized Lorenz-Mie theory show that the new method can provide a PDA system free from the measurement-volume effect.

  14. Adaptive Finite Volume Method for the Shallow Water Equations on Triangular Grids

    Directory of Open Access Journals (Sweden)

    Sudi Mungkasi

    2016-01-01

    Full Text Available This paper presents a numerical entropy production (NEP scheme for two-dimensional shallow water equations on unstructured triangular grids. We implement NEP as the error indicator for adaptive mesh refinement or coarsening in solving the shallow water equations using a finite volume method. Numerical simulations show that NEP is successful to be a refinement/coarsening indicator in the adaptive mesh finite volume method, as the method refines the mesh or grids around nonsmooth regions and coarsens them around smooth regions.

  15. A novel OPC method to reduce mask volume with yield-aware dissection

    International Nuclear Information System (INIS)

    Xie Chunlei; Chen Ye; Shi Zheng

    2013-01-01

    Growing data volume of masks tremendously increases manufacture cost. The cost increase is partially due to the complicated optical proximity corrections applied on mask design. In this paper, a yield-aware dissection method is presented. Based on the recognition of yield related mask context, the dissection result provides sufficient degrees of freedom to keep fidelity on critical sites while still retaining the frugality of modified designs. Experiments show that the final mask volume using the new method is reduced to about 50% of the conventional method. (semiconductor technology)

  16. A lattice Boltzmann coupled to finite volumes method for solving phase change problems

    Directory of Open Access Journals (Sweden)

    El Ganaoui Mohammed

    2009-01-01

    Full Text Available A numerical scheme coupling lattice Boltzmann and finite volumes approaches has been developed and qualified for test cases of phase change problems. In this work, the coupled partial differential equations of momentum conservation equations are solved with a non uniform lattice Boltzmann method. The energy equation is discretized by using a finite volume method. Simulations show the ability of this developed hybrid method to model the effects of convection, and to predict transfers. Benchmarking is operated both for conductive and convective situation dominating solid/liquid transition. Comparisons are achieved with respect to available analytical solutions and experimental results.

  17. Three-Dimensional Phase Field Simulations of Hysteresis and Butterfly Loops by the Finite Volume Method

    International Nuclear Information System (INIS)

    Xi Li-Ying; Chen Huan-Ming; Zheng Fu; Gao Hua; Tong Yang; Ma Zhi

    2015-01-01

    Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg–Landau equations using a finite volume method. The influence of externally mechanical loadings with a tensile strain and a compressive strain on the hysteresis and butterfly loops is studied numerically. Different from the traditional finite element and finite difference methods, the finite volume method is applicable to simulate the ferroelectric phase transitions and properties of ferroelectric materials even for more realistic and physical problems. (paper)

  18. The discrete ordinate method in association with the finite-volume method in non-structured mesh; Methode des ordonnees discretes associee a la methode des volumes finis en maillage non structure

    Energy Technology Data Exchange (ETDEWEB)

    Le Dez, V; Lallemand, M [Ecole Nationale Superieure de Mecanique et d` Aerotechnique (ENSMA), 86 - Poitiers (France); Sakami, M; Charette, A [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees

    1997-12-31

    The description of an efficient method of radiant heat transfer field determination in a grey semi-transparent environment included in a 2-D polygonal cavity with surface boundaries that reflect the radiation in a purely diffusive manner is proposed, at the equilibrium and in radiation-conduction coupling situation. The technique uses simultaneously the finite-volume method in non-structured triangular mesh, the discrete ordinate method and the ray shooting method. The main mathematical developments and comparative results with the discrete ordinate method in orthogonal curvilinear coordinates are included. (J.S.) 10 refs.

  19. The discrete ordinate method in association with the finite-volume method in non-structured mesh; Methode des ordonnees discretes associee a la methode des volumes finis en maillage non structure

    Energy Technology Data Exchange (ETDEWEB)

    Le Dez, V.; Lallemand, M. [Ecole Nationale Superieure de Mecanique et d`Aerotechnique (ENSMA), 86 - Poitiers (France); Sakami, M.; Charette, A. [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees

    1996-12-31

    The description of an efficient method of radiant heat transfer field determination in a grey semi-transparent environment included in a 2-D polygonal cavity with surface boundaries that reflect the radiation in a purely diffusive manner is proposed, at the equilibrium and in radiation-conduction coupling situation. The technique uses simultaneously the finite-volume method in non-structured triangular mesh, the discrete ordinate method and the ray shooting method. The main mathematical developments and comparative results with the discrete ordinate method in orthogonal curvilinear coordinates are included. (J.S.) 10 refs.

  20. An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions.

    Science.gov (United States)

    Hummelink, S; Verhulst, Arico C; Maal, Thomas J J; Hoogeveen, Yvonne L; Schultze Kool, Leo J; Ulrich, Dietmar J O

    2017-07-01

    Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available nowadays, we can combine information to preoperatively plan the optimal flap volume to be harvested. In this proof-of-concept, we investigated whether projection of a virtual flap planning onto the patient's abdomen using a projection method could result in harvesting the correct flap volume. In six patients (n = 9 breasts), 3D stereophotogrammetry and CTA data were combined from which a virtual flap planning was created comprising perforator locations, blood vessel trajectory and flap size. All projected perforators were verified with Doppler ultrasound. Intraoperative flap measurements were collected to validate the determined flap delineation volume. The measured breast volume using 3D stereophotogrammetry was 578 ± 127 cc; on CTA images, 527 ± 106 cc flap volumes were planned. The nine harvested flaps weighed 533 ± 109 g resulting in a planned versus harvested flap mean difference of 5 ± 27 g (flap density 1.0 g/ml). In 41 out of 42 projected perforator locations, a Doppler signal was audible. This proof-of-concept shows in small numbers that flap volumes can be included into a virtual DIEP flap planning, and transferring the virtual planning to the patient through a projection method results in harvesting approximately the same volume during surgery. In our opinion, this innovative approach is the first step in consequently achieving symmetric breast volumes in DIEP flap breast reconstructions. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  1. A control volume based finite difference method for solving the equilibrium equations in terms of displacements

    DEFF Research Database (Denmark)

    Hattel, Jesper; Hansen, Preben

    1995-01-01

    This paper presents a novel control volume based FD method for solving the equilibrium equations in terms of displacements, i.e. the generalized Navier equations. The method is based on the widely used cv-FDM solution of heat conduction and fluid flow problems involving a staggered grid formulati....... The resulting linear algebraic equations are solved by line-Gauss-Seidel....

  2. ADSA Foundation Scholar Award: Trends in culture-independent methods for assessing dairy food quality and safety: emerging metagenomic tools.

    Science.gov (United States)

    Yeung, Marie

    2012-12-01

    Enhancing the quality and safety of dairy food is critical to maintaining the competitiveness of dairy products in the food and beverage market and in reinforcing consumer confidence in the dairy industry. Raw milk quality has a significant effect on finished product quality. Several microbial groups found in raw milk have been shown to adversely affect the shelf life of pasteurized milk. Current microbiological criteria used to define milk quality are based primarily on culture-dependent methods, some of which are perceived to lack the desired sensitivity and specificity. To supplement traditional methods, culture-independent methods are increasingly being used to identify specific species or microbial groups, and to detect indicator genes or proteins in raw milk or dairy products. Some molecular subtyping techniques have been developed to track the transmission of microbes in dairy environments. The burgeoning "-omics" technologies offer new and exciting opportunities to enhance our understanding of food quality and safety in relation to microbes. Metagenomics has the potential to characterize microbial diversity, detect nonculturable microbes, and identify unique sequences or other factors associated with dairy product quality and safety. In this review, fluid milk will be used as the primary example to examine the adequacy and validity of conventional methods, the current trend of culture-independent methods, and the potential applications of metagenomics in dairy food research. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. X-Ray analysis and methods for nondestructive control (On the 100-anniversary of X-ray foundation)

    International Nuclear Information System (INIS)

    Sosnin, F.R.

    1995-01-01

    Brief consideration is given to the history of X-ray discovery, formation of domestic X-ray industry. Principles of operation and potentialities of X-ray diffraction analysis, gammagraphy, radioscopy, radiometric analysis are described briefly. Domestic and foreign scientists, institutes and companies who contributed much to development of methods for nondestructive control are listed

  4. New Internet search volume-based weighting method for integrating various environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Changyoon, E-mail: changyoon@yonsei.ac.kr; Hong, Taehoon, E-mail: hong7@yonsei.ac.kr

    2016-01-15

    Weighting is one of the steps in life cycle impact assessment that integrates various characterized environmental impacts as a single index. Weighting factors should be based on the society's preferences. However, most previous studies consider only the opinion of some people. Thus, this research proposes a new weighting method that determines the weighting factors of environmental impact categories by considering public opinion on environmental impacts using the Internet search volumes for relevant terms. To validate the new weighting method, the weighting factors for six environmental impacts calculated by the new weighting method were compared with the existing weighting factors. The resulting Pearson's correlation coefficient between the new and existing weighting factors was from 0.8743 to 0.9889. It turned out that the new weighting method presents reasonable weighting factors. It also requires less time and lower cost compared to existing methods and likewise meets the main requirements of weighting methods such as simplicity, transparency, and reproducibility. The new weighting method is expected to be a good alternative for determining the weighting factor. - Highlight: • A new weighting method using Internet search volume is proposed in this research. • The new weighting method reflects the public opinion using Internet search volume. • The correlation coefficient between new and existing weighting factors is over 0.87. • The new weighting method can present the reasonable weighting factors. • The proposed method can be a good alternative for determining the weighting factors.

  5. New Internet search volume-based weighting method for integrating various environmental impacts

    International Nuclear Information System (INIS)

    Ji, Changyoon; Hong, Taehoon

    2016-01-01

    Weighting is one of the steps in life cycle impact assessment that integrates various characterized environmental impacts as a single index. Weighting factors should be based on the society's preferences. However, most previous studies consider only the opinion of some people. Thus, this research proposes a new weighting method that determines the weighting factors of environmental impact categories by considering public opinion on environmental impacts using the Internet search volumes for relevant terms. To validate the new weighting method, the weighting factors for six environmental impacts calculated by the new weighting method were compared with the existing weighting factors. The resulting Pearson's correlation coefficient between the new and existing weighting factors was from 0.8743 to 0.9889. It turned out that the new weighting method presents reasonable weighting factors. It also requires less time and lower cost compared to existing methods and likewise meets the main requirements of weighting methods such as simplicity, transparency, and reproducibility. The new weighting method is expected to be a good alternative for determining the weighting factor. - Highlight: • A new weighting method using Internet search volume is proposed in this research. • The new weighting method reflects the public opinion using Internet search volume. • The correlation coefficient between new and existing weighting factors is over 0.87. • The new weighting method can present the reasonable weighting factors. • The proposed method can be a good alternative for determining the weighting factors.

  6. A simple, quantitative method using alginate gel to determine rat colonic tumor volume in vivo.

    Science.gov (United States)

    Irving, Amy A; Young, Lindsay B; Pleiman, Jennifer K; Konrath, Michael J; Marzella, Blake; Nonte, Michael; Cacciatore, Justin; Ford, Madeline R; Clipson, Linda; Amos-Landgraf, James M; Dove, William F

    2014-04-01

    Many studies of the response of colonic tumors to therapeutics use tumor multiplicity as the endpoint to determine the effectiveness of the agent. These studies can be greatly enhanced by accurate measurements of tumor volume. Here we present a quantitative method to easily and accurately determine colonic tumor volume. This approach uses a biocompatible alginate to create a negative mold of a tumor-bearing colon; this mold is then used to make positive casts of dental stone that replicate the shape of each original tumor. The weight of the dental stone cast correlates highly with the weight of the dissected tumors. After refinement of the technique, overall error in tumor volume was 16.9% ± 7.9% and includes error from both the alginate and dental stone procedures. Because this technique is limited to molding of tumors in the colon, we utilized the Apc(Pirc/+) rat, which has a propensity for developing colonic tumors that reflect the location of the majority of human intestinal tumors. We have successfully used the described method to determine tumor volumes ranging from 4 to 196 mm³. Alginate molding combined with dental stone casting is a facile method for determining tumor volume in vivo without costly equipment or knowledge of analytic software. This broadly accessible method creates the opportunity to objectively study colonic tumors over time in living animals in conjunction with other experiments and without transferring animals from the facility where they are maintained.

  7. Gastrointestinal tract volume measurement method using a compound eye type endoscope

    Science.gov (United States)

    Yoshimoto, Kayo; Yamada, Kenji; Watabe, Kenji; Kido, Michiko; Nagakura, Toshiaki; Takahashi, Hideya; Nishida, Tsutomu; Iijima, Hideki; Tsujii, Masahiko; Takehara, Tetsuo; Ohno, Yuko

    2015-03-01

    We propose an intestine volume measurement method using a compound eye type endoscope. This method aims at assessment of the gastrointestinal function. Gastrointestinal diseases are mainly based on morphological abnormalities. However, gastrointestinal symptoms are sometimes apparent without visible abnormalities. Such diseases are called functional gastrointestinal disorder, for example, functional dyspepsia, and irritable bowel syndrome. One of the major factors for these diseases is abnormal gastrointestinal motility. For the diagnosis of the gastrointestinal tract, both aspects of organic and functional assessment is important. While endoscopic diagnosis is essential for assessment of organic abnormalities, three-dimensional information is required for assessment of the functional abnormalities. Thus, we proposed the three dimensional endoscope system using compound eye. In this study, we forces on the volume of gastrointestinal tract. The volume of the gastrointestinal tract is thought to related its function. In our system, we use a compound eye type endoscope system to obtain three-dimensional information of the tract. The volume can be calculated by integrating the slice data of the intestine tract shape using the obtained three-dimensional information. First, we evaluate the proposed method by known-shape tube. Then, we confirm that the proposed method can measure the tract volume using the tract simulated model. Our system can assess the wall of gastrointestinal tract directly in a three-dimensional manner. Our system can be used for examination of gastric morphological and functional abnormalities.

  8. Visualizing Volume to Help Students Understand the Disk Method on Calculus Integral Course

    Science.gov (United States)

    Tasman, F.; Ahmad, D.

    2018-04-01

    Many research shown that students have difficulty in understanding the concepts of integral calculus. Therefore this research is interested in designing a classroom activity integrated with design research method to assist students in understanding the integrals concept especially in calculating the volume of rotary objects using disc method. In order to support student development in understanding integral concepts, this research tries to use realistic mathematical approach by integrating geogebra software. First year university student who takes a calculus course (approximately 30 people) was chosen to implement the classroom activity that has been designed. The results of retrospective analysis show that visualizing volume of rotary objects using geogebra software can assist the student in understanding the disc method as one way of calculating the volume of a rotary object.

  9. Polish Foundation for Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Polish Foundation for Energy Efficiency (FEWE) was established in Poland at the end of 1990. FEWE, as an independent and non-profit organization, has the following objectives: to strive towards an energy efficient national economy, and to show the way and methods by use of which energy efficiency can be increased. The activity of the Foundation covers the entire territory of Poland through three regional centers: in Warsaw, Katowice and Cracow. FEWE employs well-known and experienced specialists within thermal and power engineering, civil engineering, economy and applied sciences. The organizer of the Foundation has been Battelle Memorial Institute - Pacific Northwest Laboratories from the USA.

  10. 3D automatic segmentation method for retinal optical coherence tomography volume data using boundary surface enhancement

    Directory of Open Access Journals (Sweden)

    Yankui Sun

    2016-03-01

    Full Text Available With the introduction of spectral-domain optical coherence tomography (SD-OCT, much larger image datasets are routinely acquired compared to what was possible using the previous generation of time-domain OCT. Thus, there is a critical need for the development of three-dimensional (3D segmentation methods for processing these data. We present here a novel 3D automatic segmentation method for retinal OCT volume data. Briefly, to segment a boundary surface, two OCT volume datasets are obtained by using a 3D smoothing filter and a 3D differential filter. Their linear combination is then calculated to generate new volume data with an enhanced boundary surface, where pixel intensity, boundary position information, and intensity changes on both sides of the boundary surface are used simultaneously. Next, preliminary discrete boundary points are detected from the A-Scans of the volume data. Finally, surface smoothness constraints and a dynamic threshold are applied to obtain a smoothed boundary surface by correcting a small number of error points. Our method can extract retinal layer boundary surfaces sequentially with a decreasing search region of volume data. We performed automatic segmentation on eight human OCT volume datasets acquired from a commercial Spectralis OCT system, where each volume of datasets contains 97 OCT B-Scan images with a resolution of 496×512 (each B-Scan comprising 512 A-Scans containing 496 pixels; experimental results show that this method can accurately segment seven layer boundary surfaces in normal as well as some abnormal eyes.

  11. Volume of Structures in the Fetal Brain Measured with a New Semiautomated Method.

    Science.gov (United States)

    Ber, R; Hoffman, D; Hoffman, C; Polat, A; Derazne, E; Mayer, A; Katorza, E

    2017-11-01

    Measuring the volume of fetal brain structures is challenging due to fetal motion, low resolution, and artifacts caused by maternal tissue. Our aim was to introduce a new, simple, Matlab-based semiautomated method to measure the volume of structures in the fetal brain and present normal volumetric curves of the structures measured. The volume of the supratentorial brain, left and right hemispheres, cerebellum, and left and right eyeballs was measured retrospectively by the new semiautomated method in MR imaging examinations of 94 healthy fetuses. Four volume ratios were calculated. Interobserver agreement was calculated with the intraclass correlation coefficient, and a Bland-Altman plot was drawn for comparison of manual and semiautomated method measurements of the supratentorial brain. We present normal volumetric curves and normal percentile values of the structures measured according to gestational age and of the ratios between the cerebellum and the supratentorial brain volume and the total eyeball and the supratentorial brain volume. Interobserver agreement was good or excellent for all structures measured. The Bland-Altman plot between manual and semiautomated measurements showed a maximal relative difference of 7.84%. We present a technologically simple, reproducible method that can be applied prospectively and retrospectively on any MR imaging protocol, and we present normal volumetric curves measured. The method shows results like manual measurements while being less time-consuming and user-dependent. By applying this method on different cranial and extracranial structures, anatomic and pathologic, we believe that fetal volumetry can turn from a research tool into a practical clinical one. © 2017 by American Journal of Neuroradiology.

  12. Semianalytical analysis of shear walls with the use of discrete-continual finite element method. Part 1: Mathematical foundations

    Directory of Open Access Journals (Sweden)

    Akimov Pavel

    2016-01-01

    Full Text Available The distinctive paper is devoted to the two-dimensional semi-analytical solution of boundary problems of analysis of shear walls with the use of discrete-continual finite element method (DCFEM. This approach allows obtaining the exact analytical solution in one direction (so-called “basic” direction, also decrease the size of the problem to one-dimensional common finite element analysis. The resulting multipoint boundary problem for the first-order system of ordinary differential equations with piecewise constant coefficients is solved analytically. The proposed method is rather efficient for evaluation of the boundary effect (such as the stress field near the concentrated force. DCFEM also has a completely computer-oriented algorithm, computational stability, optimal conditionality of resultant system and it is applicable for the various loads at an arbitrary point or a region of the wall.

  13. Endoscopic clipping for gastrointestinal tumors. A method to define the target volume more precisely

    International Nuclear Information System (INIS)

    Riepl, M.; Klautke, G.; Fehr, R.; Fietkau, R.; Pietsch, A.

    2000-01-01

    Background: In many cases it is not possible to exactly define the extension of carcinoma of the gastrointestinal tract with the help of computertomography scans made for 3-D-radiation treatment planning. Consequently, the planning of external beam radiotherapy is made more difficult for the gross tumor volume as well as, in some cases, also for the clinical target volume. Patients and Methods: Eleven patients with macrosocpic tumors (rectal cancer n = 5, cardiac cancer n = 6) were included. Just before 3-D planning, the oral and aboral border of the tumor was marked endoscopically with hemoclips. Subsequently, CT scans for radiotherapy planning were made and the clinical target volume was defined. Five to 6 weeks thereafter, new CT scans were done to define the gross tumor volume for boost planning. Two investigators independently assessed the influence of the hemoclips on the different planning volumes, and whether the number of clips was sufficient to define the gross tumor volume. Results: In all patients, the implantation of the clips was done without complications. Start of radiotherapy was not delayed. With the help of the clips it was possible to exactly define the position and the extension of the primary tumor. The clinical target volume was modified according to the position of the clips in 5/11 patients; the gross tumor volume was modified in 7/11 patients. The use of the clips made the documentation and verification of the treatment portals by the simulator easier. Moreover, the clips helped the surgeon to define the primary tumor region following marked regression after neoadjuvant therapy in 3 patients. Conclusions: Endoscopic clipping of gastrointestinal tumors helps to define the tumor volumes more precisely in radiation therapy. The clips are easily recognized on the portal films and, thus, contribute to quality control. (orig.) [de

  14. Rio Grande Floodway, Truth or Consequences Unit, NM, Cuchillo Negro Dam Foundation Report. Volume 3. Appendix E, Appendix F and Appendix G

    Science.gov (United States)

    1992-12-01

    a 50 per cent reduction in explosives load. The explosives should be well distributed in the hole using decks and detonating cord do- nlines . Line...8217 Handbook Describing Practical Methods of Using Explosives for Various Purposes 0 Prepared by TECHNICAL MARKETING SERVICES - EXPLOSIVES Sixth Edition

  15. Weibull statistics effective area and volume in the ball-on-ring testing method

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund

    2014-01-01

    The ball-on-ring method is together with other biaxial bending methods often used for measuring the strength of plates of brittle materials, because machining defects are remote from the high stresses causing the failure of the specimens. In order to scale the measured Weibull strength...... to geometries relevant for the application of the material, the effective area or volume for the test specimen must be evaluated. In this work analytical expressions for the effective area and volume of the ball-on-ring test specimen is derived. In the derivation the multiaxial stress field has been accounted...

  16. Hybrid Finite Element and Volume Integral Methods for Scattering Using Parametric Geometry

    DEFF Research Database (Denmark)

    Volakis, John L.; Sertel, Kubilay; Jørgensen, Erik

    2004-01-01

    n this paper we address several topics relating to the development and implementation of volume integral and hybrid finite element methods for electromagnetic modeling. Comparisons of volume integral equation formulations with the finite element-boundary integral method are given in terms of accu...... of vanishing divergence within the element but non-zero curl. In addition, a new domain decomposition is introduced for solving array problems involving several million degrees of freedom. Three orders of magnitude CPU reduction is demonstrated for such applications....

  17. Superolateral Hoffa's fat pad (SHFP) oedema and patellar cartilage volume loss: quantitative analysis using longitudinal data from the Foundation for the National Institute of Health (FNIH) Osteoarthritis Biomarkers Consortium.

    Science.gov (United States)

    Haj-Mirzaian, Arya; Guermazi, Ali; Hafezi-Nejad, Nima; Sereni, Christopher; Hakky, Michael; Hunter, David J; Zikria, Bashir; Roemer, Frank W; Demehri, Shadpour

    2018-04-12

    To determine the association of superolateral Hoffa's fat pad (SHFP) oedema and patellofemoral joint structural damage in participants of Foundation for the National Institute of Health Osteoarthritis Biomarkers Consortium study. Baseline and 24-month MRIs of 600 subjects were assessed. The presence of SHFP oedema (using 0-3 grading scale) and patellar morphology metrics were determined using baseline MRI. Quantitative patellar cartilage volume and semi-quantitative MRI osteoarthritis knee score (MOAKS) variables were extracted. The associations between SHFP oedema and patellar cartilage damage, bone marrow lesion (BML), osteophyte and morphology were evaluated in cross-sectional model. In longitudinal analysis, the associations between oedema and cartilage volume loss (defined using reliable change index) and MOAKS worsening were evaluated. In cross-sectional evaluations, the presence of SHFP oedema was associated with simultaneous lateral patellar cartilage/BML defects and inferior-medial patellar osteophyte size. A significant positive correlation between the degree of patella alta and SHFP oedema was detected (r = 0.259, p < 0.001). The presence of oedema was associated with 24-month cartilage volume loss (odds ratio (OR) 2.11, 95% confidence interval 1.46-3.06) and medial patellar BML size (OR 1.92 (1.15-3.21)) and number (OR 2.50 (1.29-4.88)) worsening. The optimal cut-off value for the grade of baseline SHFP oedema regarding both presence and worsening of patellar structural damage was ≥ 1 (presence of any SHFP hyperintensity). The presence of SHFP oedema could be considered as a predictor of future patellar cartilage loss and BML worsening, and an indicator of simultaneous cartilage, BML and osteophyte defects. • SHFP oedema was associated with simultaneous lateral patellar OA-related structural damage. • SHFP oedema was associated with longitudinal patellar cartilage loss over 24 months. • SHFP oedema could be considered as indicator and predictor

  18. A novel method for the evaluation of uncertainty in dose-volume histogram computation.

    Science.gov (United States)

    Henríquez, Francisco Cutanda; Castrillón, Silvia Vargas

    2008-03-15

    Dose-volume histograms (DVHs) are a useful tool in state-of-the-art radiotherapy treatment planning, and it is essential to recognize their limitations. Even after a specific dose-calculation model is optimized, dose distributions computed by using treatment-planning systems are affected by several sources of uncertainty, such as algorithm limitations, measurement uncertainty in the data used to model the beam, and residual differences between measured and computed dose. This report presents a novel method to take them into account. To take into account the effect of associated uncertainties, a probabilistic approach using a new kind of histogram, a dose-expected volume histogram, is introduced. The expected value of the volume in the region of interest receiving an absorbed dose equal to or greater than a certain value is found by using the probability distribution of the dose at each point. A rectangular probability distribution is assumed for this point dose, and a formulation that accounts for uncertainties associated with point dose is presented for practical computations. This method is applied to a set of DVHs for different regions of interest, including 6 brain patients, 8 lung patients, 8 pelvis patients, and 6 prostate patients planned for intensity-modulated radiation therapy. Results show a greater effect on planning target volume coverage than in organs at risk. In cases of steep DVH gradients, such as planning target volumes, this new method shows the largest differences with the corresponding DVH; thus, the effect of the uncertainty is larger.

  19. Study of Anti-Sliding Stability of a Dam Foundation Based on the Fracture Flow Method with 3D Discrete Element Code

    Directory of Open Access Journals (Sweden)

    Chong Shi

    2017-10-01

    Full Text Available Fractured seepage is an important factor affecting the interface stability of rock mass. It is closely related to fracture properties and hydraulic conditions. In this study, the law of seepage in a single fracture surface based on modified cubic law is described, and the three-dimensional discrete element method is used to simulate the dam foundation structure of the Capulin San Pablo (Costa Rica hydropower station. The effect of construction joints and developed structure on dam stability is studied, and its permeability law and sliding stability are also evaluated. It is found that the hydraulic-mechanical coupling with strength reduction method in DEM is more appropriate to use to study the seepage-related problems of fractured rock mass, which considers practical conditions, such as the roughness of and the width of fracture. The strength reduction method provides a more accurate safety factor of dam when considering the deformation coordination with bedrocks. It is an important method with which to study the stability of seepage conditions in complex structures. The discrete method also provided an effective and reasonable way of determining seepage control measures.

  20. A method for bubble volume calculating in vertical two-phase flow

    International Nuclear Information System (INIS)

    Wang, H Y; Dong, F

    2009-01-01

    The movement of bubble is a basic subject in gas-liquid two-phase flow research. A method for calculating bubble volume which is one of the most important characters in bubble motion research was proposed. A suit of visualized experimental device was designed and set up. Single bubble rising in stagnant liquid in a rectangular tank was studied using the high-speed video system. Bubbles generated by four orifice with different diameter (1mm, 2mm, 3mm, 4mm) were recorded respectively. Sequences of recorded high-speed images were processed by digital image processing method, such as image noise remove, binary image transform, bubble filling, and so on. then, Several parameters could be obtained from the processed image. Bubble area, equivalent diameter, bubble velocity, bubble acceleration are all indispensable in bubble volume calculating. In order to get the force balance equation, forces that work on bubble along vertical direction, including drag force, virtual mass force, buoyancy, gravity and liquid thrust, were analyzed. Finally, the bubble volume formula could be derived from the force balance equation and bubble parameters. Examples were given to shown the computing process and results. Comparison of the bubble volume calculated by geomettic method and the present method have shown the superiority of the proposed method in this paper.

  1. /sup 3/H-dextran method for measurements of the blood volume in the rat choroid

    Energy Technology Data Exchange (ETDEWEB)

    Matsusaka, T [Osaka Prefectural Center for Adult Diseases (Japan); Morimoto, K; Kikkawa, Y

    1980-01-01

    A new method was developed using /sup 3/H-dextran for measuring the blood volume in the choroid. Under pentobarbital-anesthesia, albino rats weighing 200 grams were perfused through the left ventricle with a 2.5 percent glutaraldehyde solution containing the radioactive dextran. The procedure allowed exchange of the choroidal blood with the /sup 3/H-dextran solution with a simultaneous fixation of the choroid. The blood volume in the choroid was calculated from the radioactivity count, which is estimated to be 1.690 x 10/sup -4/ ml per mg wet weight and 5.070 x 10/sup -4/ ml per mg dry weight. Epinephrine subconjunctivally injected diminished the blood volume in the choroid by 68 percent. Pretreatment with lidocaine almost nullified the effect of epinephrine. Applicability of this method to the analytical study of the choroidal circulation is discussed.

  2. 3H-dextran method for measurements of the blood volume in the rat choroid

    International Nuclear Information System (INIS)

    Matsusaka, Toshihiko; Morimoto, Kazuhiro; Kikkawa, Yoshizo.

    1980-01-01

    A new method was developed using 3 H-dextran for measuring the blood volume in the choroid. Under pentobarbital-anesthesia, albino rats weighing 200 grams were perfused through the left ventricle with a 2.5 percent glutaraldehyde solution containing the radioactive dextran. The procedure allowed exchange of the choroidal blood with the 3 H-dextran solution with a simultaneous fixation of the choroid. The blood volume in the choroid was calculated from the radioactivity count, which is estimated to be 1.690 x 10 -4 ml per mg wet weight and 5.070 x 10 -4 ml per mg dry weight. Epinephrine subconjunctivally injected diminished the blood volume in the choroid by 68 percent. Pretreatment with lidocaine almost nullified the effect of epinephrine. Applicability of this method to the analytical study of the choroidal circulation is discussed. (author)

  3. A Novel Grey Wave Method for Predicting Total Chinese Trade Volume

    Directory of Open Access Journals (Sweden)

    Kedong Yin

    2017-12-01

    Full Text Available The total trade volume of a country is an important way of appraising its international trade situation. A prediction based on trade volume will help enterprises arrange production efficiently and promote the sustainability of the international trade. Because the total Chinese trade volume fluctuates over time, this paper proposes a Grey wave forecasting model with a Hodrick–Prescott filter (HP filter to forecast it. This novel model first parses time series into long-term trend and short-term cycle. Second, the model uses a general GM (1,1 to predict the trend term and the Grey wave forecasting model to predict the cycle term. Empirical analysis shows that the improved Grey wave prediction method provides a much more accurate forecast than the basic Grey wave prediction method, achieving better prediction results than autoregressive moving average model (ARMA.

  4. Gastropod shell size and architecture influence the applicability of methods used to estimate internal volume.

    Science.gov (United States)

    Ragagnin, Marilia Nagata; Gorman, Daniel; McCarthy, Ian Donald; Sant'Anna, Bruno Sampaio; de Castro, Cláudio Campi; Turra, Alexander

    2018-01-11

    Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g., computed tomography (CT). This study undertakes the first assessment of the measurement reproducibility of three contrasting approaches across a spectrum of shell architectures and sizes. While our results suggested a certain level of variability inherent for all methods, we conclude that a single measure using sand/water is likely to be sufficient for the majority of studies. However, care must be taken as precision may decline with increasing shell size and structural complexity. CT provided less variation between repeat measures but volume estimates were consistently lower compared to sand/water and will need methodological improvements before it can be used as an alternative. CT indicated volume may be also underestimated using sand/water due to the presence of air spaces visible in filled shells scanned by CT. Lastly, we encourage authors to clearly describe how volume estimates were obtained.

  5. The Development of a Finite Volume Method for Modeling Sound in Coastal Ocean Environment

    Energy Technology Data Exchange (ETDEWEB)

    Long, Wen; Yang, Zhaoqing; Copping, Andrea E.; Jung, Ki Won; Deng, Zhiqun

    2015-10-28

    : As the rapid growth of marine renewable energy and off-shore wind energy, there have been concerns that the noises generated from construction and operation of the devices may interfere marine animals’ communication. In this research, a underwater sound model is developed to simulate sound prorogation generated by marine-hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite volume and finite difference methods are developed to solve the 3D Helmholtz equation of sound propagation in the coastal environment. For finite volume method, the grid system consists of triangular grids in horizontal plane and sigma-layers in vertical dimension. A 3D sparse matrix solver with complex coefficients is formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method is applied to efficiently solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model is then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generated by human activities in a range-dependent setting, such as offshore wind energy platform constructions and tidal stream turbines. As a proof of concept, initial validation of the finite difference solver is presented for two coastal wedge problems. Validation of finite volume method will be reported separately.

  6. The Finite Elements Method (FEM versus traditional Methods (TM, in the estimation of settlement and modulus of soil reaction for foundation slabs design on soils with natural or man-made cavities

    Directory of Open Access Journals (Sweden)

    Escolano-Sánchez, F.

    2015-03-01

    Full Text Available Direct foundations with continuous elements, such as slabs, provide more advantages than direct foundations with isolated elements, such as footings, and deep foundations, such as piles, in the case of soil with natural or man-made cavities. The slabs are usually designed by two-dimensional models which show their shape on the plant, on a lineal elastic support, represented by a modulus of soil reaction. Regarding the settlement estimation, the following article compares the Finite Elements Method (FEM versus the classical Method (CM to select the modulus of soil reaction used to design foundations slabs in sensitive soils and sites with possible cavities or collapses. This analysis includes one of these cavities in the design to evaluate the risk of fail.Las cimentaciones directas con elementos continuos «losas», tienen ventajas sobre las cimentaciones directas con elementos aislados «zapatas» y sobre las cimentaciones profundas «pilotes», frente a la presencia de terrenos problemáticos. Las losas se diseñan de forma habitual con modelos bidimensionales que representan su forma en planta, apoyada en un medio elástico y lineal, representado por un módulo de balasto. En el presente artículo se realiza un análisis comparativo, para la estimación de asientos, entre el Método de Elementos Finitos (FEM y el Método Clásico (MC, para la elección de los módulos de balasto que se utilizan en el diseño de losas de cimentación en terrenos con blandones y cavidades naturales o antrópicas. Este análisis considera el peligro de la presencia de una de estas cavidades dentro de su diseño, de esta forma, el riesgo de fallo puede ser valorado por ambos métodos.

  7. Volume Measurement Algorithm for Food Product with Irregular Shape using Computer Vision based on Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Joko Siswantoro

    2014-11-01

    Full Text Available Volume is one of important issues in the production and processing of food product. Traditionally, volume measurement can be performed using water displacement method based on Archimedes’ principle. Water displacement method is inaccurate and considered as destructive method. Computer vision offers an accurate and nondestructive method in measuring volume of food product. This paper proposes algorithm for volume measurement of irregular shape food product using computer vision based on Monte Carlo method. Five images of object were acquired from five different views and then processed to obtain the silhouettes of object. From the silhouettes of object, Monte Carlo method was performed to approximate the volume of object. The simulation result shows that the algorithm produced high accuracy and precision for volume measurement.

  8. ACARP Project C10059. ACARP manual of modern coal testing methods. Volume 1: The manual

    Energy Technology Data Exchange (ETDEWEB)

    Sakurovs, R.; Creelman, R.; Pohl, J.; Juniper, L. [CSIRO Energy Technology, Sydney, NSW (Australia)

    2002-07-01

    The Manual summarises the purpose, applicability, and limitations of a range of standard and modern coal testing methods that have potential to assist the coal company technologist to better evaluate coal performance. The first volume sets out the Modern Coal Testing Methods in summarised form that can be used as a quick guide to practitioners to assist in selecting the best technique to solve their problems.

  9. Precision of a new bedside method for estimation of the circulating blood volume

    DEFF Research Database (Denmark)

    Christensen, P; Eriksen, B; Henneberg, S W

    1993-01-01

    The present study is a theoretical and experimental evaluation of a modification of the carbon monoxide method for estimation of the circulating blood volume (CBV) with respect to the precision of the method. The CBV was determined from measurements of the CO-saturation of hemoglobin before and a......, determination of CBV can be performed with an amount of CO that gives rise to a harmless increase in the carboxyhemoglobin concentration.(ABSTRACT TRUNCATED AT 250 WORDS)...

  10. New finite volume methods for approximating partial differential equations on arbitrary meshes

    International Nuclear Information System (INIS)

    Hermeline, F.

    2008-12-01

    This dissertation presents some new methods of finite volume type for approximating partial differential equations on arbitrary meshes. The main idea lies in solving twice the problem to be dealt with. One addresses the elliptic equations with variable (anisotropic, antisymmetric, discontinuous) coefficients, the parabolic linear or non linear equations (heat equation, radiative diffusion, magnetic diffusion with Hall effect), the wave type equations (Maxwell, acoustics), the elasticity and Stokes'equations. Numerous numerical experiments show the good behaviour of this type of method. (author)

  11. Constitutive Modelling in Thermomechanical Processes, Using The Control Volume Method on Staggered Grid

    DEFF Research Database (Denmark)

    Thorborg, Jesper

    , however, is constituted by the implementation of the $J_2$ flow theory in the control volume method. To apply the control volume formulation on the process of hardening concrete viscoelastic stress-strain models has been examined in terms of various rheological models. The generalized 3D models are based...... on two different suggestions in the literature, that is compressible or incompressible behaviour of the viscos response in the dashpot element. Numerical implementation of the models has shown very good agreement with corresponding analytical solutions. The viscoelastic solid mechanical model is used...

  12. Simulation of pore pressure accumulation under cyclic loading using Finite Volume Method

    DEFF Research Database (Denmark)

    Tang, Tian; Hededal, Ole

    2014-01-01

    This paper presents a finite volume implementation of a porous, nonlinear soil model capable of simulating pore pressure accumulation under cyclic loading. The mathematical formulations are based on modified Biot’s coupled theory by substituting the original elastic constitutive model...... with an advanced elastoplastic model suitable for describing monotonic as well as cyclic loading conditions. The finite volume method is applied to discretize these formulations. The resulting set of coupled nonlinear algebraic equations are then solved by a ’segregated’ solution procedure. An efficient return...

  13. Foundations for renewables

    Energy Technology Data Exchange (ETDEWEB)

    Neidlein, H.C. [German Agency Scherer Schnell Walser und Partner (Germany)

    2007-07-01

    In Germany, 77 foundations promote renewable energy technology with around Euro 25 million annually. The most important internationally active foundations, however, can be found in the Anglo-Saxon countries. (orig.)

  14. Toxicology Education Foundation

    Science.gov (United States)

    ... bodies and our world. Welcome to the Toxicology Education Foundation! Our mission is to enhance public understanding ... In with us, follow our Tweets, choose Toxicology Education Foundation as your preferred charity through Smile.Amazon. ...

  15. Skin Cancer Foundation

    Science.gov (United States)

    ... Host a Fundraising Event | About Us | Store The Skin Cancer Foundation The Skin Cancer Foundation is the ... Handbook A "Sunscreen Gene"? Skin Cancer Facts & Statistics Skin Cancer Treatment Glossary Information on medications and procedures ...

  16. Robert Wood Johnson Foundation

    Science.gov (United States)

    Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We Work Grants ... Learn more For Grantees and Grantseekers The Robert Wood Johnson Foundation funds a wide array of programs ...

  17. Curvature computation in volume-of-fluid method based on point-cloud sampling

    Science.gov (United States)

    Kassar, Bruno B. M.; Carneiro, João N. E.; Nieckele, Angela O.

    2018-01-01

    This work proposes a novel approach to compute interface curvature in multiphase flow simulation based on Volume of Fluid (VOF) method. It is well documented in the literature that curvature and normal vector computation in VOF may lack accuracy mainly due to abrupt changes in the volume fraction field across the interfaces. This may cause deterioration on the interface tension forces estimates, often resulting in inaccurate results for interface tension dominated flows. Many techniques have been presented over the last years in order to enhance accuracy in normal vectors and curvature estimates including height functions, parabolic fitting of the volume fraction, reconstructing distance functions, coupling Level Set method with VOF, convolving the volume fraction field with smoothing kernels among others. We propose a novel technique based on a representation of the interface by a cloud of points. The curvatures and the interface normal vectors are computed geometrically at each point of the cloud and projected onto the Eulerian grid in a Front-Tracking manner. Results are compared to benchmark data and significant reduction on spurious currents as well as improvement in the pressure jump are observed. The method was developed in the open source suite OpenFOAM® extending its standard VOF implementation, the interFoam solver.

  18. A simple method to estimate restoration volume as a possible predictor for tooth fracture.

    Science.gov (United States)

    Sturdevant, J R; Bader, J D; Shugars, D A; Steet, T C

    2003-08-01

    Many dentists cite the fracture risk posed by a large existing restoration as a primary reason for their decision to place a full-coverage restoration. However, there is poor agreement among dentists as to when restoration placement is necessary because of the inability to make objective measurements of restoration size. The purpose of this study was to compare a new method to estimate restoration volumes in posterior teeth with analytically determined volumes. True restoration volume proportion (RVP) was determined for 96 melamine typodont teeth: 24 each of maxillary second premolar, mandibular second premolar, maxillary first molar, and mandibular first molar. Each group of 24 was subdivided into 3 groups to receive an O, MO, or MOD amalgam preparation design. Each preparation design was further subdivided into 4 groups of increasingly larger size. The density of amalgam used was calculated according to ANSI/ADA Specification 1. The teeth were weighed before and after restoration with amalgam. Restoration weight was calculated, and the density of amalgam was used to calculate restoration volume. A liquid pycnometer was used to calculate coronal volume after sectioning the anatomic crown from the root horizontally at the cementoenamel junction. True RVP was calculated by dividing restoration volume by coronal volume. An occlusal photograph and a bitewing radiograph were made of each restored tooth to provide 2 perpendicular views. Each image was digitized, and software was used to measure the percentage of the anatomic crown restored with amalgam. Estimated RVP was calculated by multiplying the percentage of the anatomic crown restored from the 2 views together. Pearson correlation coefficients were used to compare estimated RVP with true RVP. The Pearson correlation coefficient of true RVP with estimated RVP was 0.97 overall (Pvolume of restorative material in coronal tooth structure. The fact that it can be done in a nondestructive manner makes it attractive for

  19. The Danish Industrial Foundations

    DEFF Research Database (Denmark)

    Thomsen, Steen

    and governed, what role it plays in the Danish economy, and how industrial foundation-owned companies perform. The book is the result of a large collaborative research project, led by the author, on industrial foundations. Some global companies such as IKEA, Robert Bosch or the Tata Group are foundation...

  20. Solar panel foundation device

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, W.W.

    1983-03-29

    A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.

  1. A flexible and accurate digital volume correlation method applicable to high-resolution volumetric images

    Science.gov (United States)

    Pan, Bing; Wang, Bo

    2017-10-01

    Digital volume correlation (DVC) is a powerful technique for quantifying interior deformation within solid opaque materials and biological tissues. In the last two decades, great efforts have been made to improve the accuracy and efficiency of the DVC algorithm. However, there is still a lack of a flexible, robust and accurate version that can be efficiently implemented in personal computers with limited RAM. This paper proposes an advanced DVC method that can realize accurate full-field internal deformation measurement applicable to high-resolution volume images with up to billions of voxels. Specifically, a novel layer-wise reliability-guided displacement tracking strategy combined with dynamic data management is presented to guide the DVC computation from slice to slice. The displacements at specified calculation points in each layer are computed using the advanced 3D inverse-compositional Gauss-Newton algorithm with the complete initial guess of the deformation vector accurately predicted from the computed calculation points. Since only limited slices of interest in the reference and deformed volume images rather than the whole volume images are required, the DVC calculation can thus be efficiently implemented on personal computers. The flexibility, accuracy and efficiency of the presented DVC approach are demonstrated by analyzing computer-simulated and experimentally obtained high-resolution volume images.

  2. A New Class of Non-Linear, Finite-Volume Methods for Vlasov Simulation

    International Nuclear Information System (INIS)

    Banks, J.W.; Hittinger, J.A.

    2010-01-01

    Methods for the numerical discretization of the Vlasov equation should efficiently use the phase space discretization and should introduce only enough numerical dissipation to promote stability and control oscillations. A new high-order, non-linear, finite-volume algorithm for the Vlasov equation that discretely conserves particle number and controls oscillations is presented. The method is fourth-order in space and time in well-resolved regions, but smoothly reduces to a third-order upwind scheme as features become poorly resolved. The new scheme is applied to several standard problems for the Vlasov-Poisson system, and the results are compared with those from other finite-volume approaches, including an artificial viscosity scheme and the Piecewise Parabolic Method. It is shown that the new scheme is able to control oscillations while preserving a higher degree of fidelity of the solution than the other approaches.

  3. Pleural liquid clearance rate measured in awake sheep by the volume of dilution method

    International Nuclear Information System (INIS)

    Broaddus, V.C.; Wiener-Kronish, J.P.; Berthiaume, Y.; Staub, N.C.

    1986-01-01

    The authors reported 24h clearance of mock pleural effusions measured terminally in sheep. To measure effusion volume at different times in the same sheep, they injected 111 In-transferrin and measured its dilution. In 5 sheep with effusions of known sizes, the method was accurate to +/-10%. In 5 awake sheep, the authors injected 10 ml/kg of a 1% protein solution via a non-penetrating rib capsule. At 6h, the authors measured the volume by the dilution method and at 24h by direct recovery. The clearance rate in each animal was constant at 2.9-6.0%/h (average 4.8 +/- 1.3%/h). This new method gives a reliable two point clearance rate and requires fewer animals

  4. ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

    International Nuclear Information System (INIS)

    Nagai, Katsuaki; Ushijima, Satoru

    2010-01-01

    A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

  5. ALE finite volume method for free-surface Bingham plastic fluids with general curvilinear coordinates

    Science.gov (United States)

    Nagai, Katsuaki; Ushijima, Satoru

    2010-06-01

    A numerical prediction method has been proposed to predict Bingham plastic fluids with free-surface in a two-dimensional container. Since the linear relationships between stress tensors and strain rate tensors are not assumed for non-Newtonian fluids, the liquid motions are described with Cauchy momentum equations rather than Navier-Stokes equations. The profile of a liquid surface is represented with the two-dimensional curvilinear coordinates which are represented in each computational step on the basis of the arbitrary Lagrangian-Eulerian (ALE) method. Since the volumes of the fluid cells are transiently changed in the physical space, the geometric conservation law is applied to the finite volume discretizations. As a result, it has been shown that the present method enables us to predict reasonably the Bingham plastic fluids with free-surface in a container.

  6. A spatial discretization of the MHD equations based on the finite volume - spectral method

    International Nuclear Information System (INIS)

    Miyoshi, Takahiro

    2000-05-01

    Based on the finite volume - spectral method, we present new discretization formulae for the spatial differential operators in the full system of the compressible MHD equations. In this approach, the cell-centered finite volume method is adopted in a bounded plane (poloidal plane), while the spectral method is applied to the differential with respect to the periodic direction perpendicular to the poloidal plane (toroidal direction). Here, an unstructured grid system composed of the arbitrary triangular elements is utilized for constructing the cell-centered finite volume method. In order to maintain the divergence free constraint of the magnetic field numerically, only the poloidal component of the rotation is defined at three edges of the triangular element. This poloidal component is evaluated under the assumption that the toroidal component of the operated vector times the radius, RA φ , is linearly distributed in the element. The present method will be applied to the nonlinear MHD dynamics in an realistic torus geometry without the numerical singularities. (author)

  7. Know your tools - concordance of different methods for measuring brain volume change after ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Yassi, Nawaf; Campbell, Bruce C.V.; Davis, Stephen M.; Bivard, Andrew [The University of Melbourne, Departments of Medicine and Neurology, Melbourne Brain Centre rate at The Royal Melbourne Hospital, Parkville, Victoria (Australia); Moffat, Bradford A.; Steward, Christopher; Desmond, Patricia M. [The University of Melbourne, Department of Radiology, The Royal Melbourne Hospital, Parkville (Australia); Churilov, Leonid [The University of Melbourne, The Florey Institute of Neurosciences and Mental Health, Parkville (Australia); Parsons, Mark W. [University of Newcastle and Hunter Medical Research Institute, Priority Research Centre for Translational Neuroscience and Mental Health, Newcastle (Australia)

    2015-07-15

    Longitudinal brain volume changes have been investigated in a number of cerebral disorders as a surrogate marker of clinical outcome. In stroke, unique methodological challenges are posed by dynamic structural changes occurring after onset, particularly those relating to the infarct lesion. We aimed to evaluate agreement between different analysis methods for the measurement of post-stroke brain volume change, and to explore technical challenges inherent to these methods. Fifteen patients with anterior circulation stroke underwent magnetic resonance imaging within 1 week of onset and at 1 and 3 months. Whole-brain as well as grey- and white-matter volume were estimated separately using both an intensity-based and a surface watershed-based algorithm. In the case of the intensity-based algorithm, the analysis was also performed with and without exclusion of the infarct lesion. Due to the effects of peri-infarct edema at the baseline scan, longitudinal volume change was measured as percentage change between the 1 and 3-month scans. Intra-class and concordance correlation coefficients were used to assess agreement between the different analysis methods. Reduced major axis regression was used to inspect the nature of bias between measurements. Overall agreement between methods was modest with strong disagreement between some techniques. Measurements were variably impacted by procedures performed to account for infarct lesions. Improvements in volumetric methods and consensus between methodologies employed in different studies are necessary in order to increase the validity of conclusions derived from post-stroke cerebral volumetric studies. Readers should be aware of the potential impact of different methods on study conclusions. (orig.)

  8. Know your tools - concordance of different methods for measuring brain volume change after ischemic stroke

    International Nuclear Information System (INIS)

    Yassi, Nawaf; Campbell, Bruce C.V.; Davis, Stephen M.; Bivard, Andrew; Moffat, Bradford A.; Steward, Christopher; Desmond, Patricia M.; Churilov, Leonid; Parsons, Mark W.

    2015-01-01

    Longitudinal brain volume changes have been investigated in a number of cerebral disorders as a surrogate marker of clinical outcome. In stroke, unique methodological challenges are posed by dynamic structural changes occurring after onset, particularly those relating to the infarct lesion. We aimed to evaluate agreement between different analysis methods for the measurement of post-stroke brain volume change, and to explore technical challenges inherent to these methods. Fifteen patients with anterior circulation stroke underwent magnetic resonance imaging within 1 week of onset and at 1 and 3 months. Whole-brain as well as grey- and white-matter volume were estimated separately using both an intensity-based and a surface watershed-based algorithm. In the case of the intensity-based algorithm, the analysis was also performed with and without exclusion of the infarct lesion. Due to the effects of peri-infarct edema at the baseline scan, longitudinal volume change was measured as percentage change between the 1 and 3-month scans. Intra-class and concordance correlation coefficients were used to assess agreement between the different analysis methods. Reduced major axis regression was used to inspect the nature of bias between measurements. Overall agreement between methods was modest with strong disagreement between some techniques. Measurements were variably impacted by procedures performed to account for infarct lesions. Improvements in volumetric methods and consensus between methodologies employed in different studies are necessary in order to increase the validity of conclusions derived from post-stroke cerebral volumetric studies. Readers should be aware of the potential impact of different methods on study conclusions. (orig.)

  9. The Reflective Foundation

    DEFF Research Database (Denmark)

    Lunde Jørgensen, Ida

    Private foundations and cultural philanthropy by élites is viewed with increasing skepticism in recent years, begging the question of the extent to which foundations reflect on their role vis a vis wider societal norms. Through the prism of the New Carlsberg Foundation, financed by the brewery...... Carlsberg A/S, the paper seeks to elucidate the way in which one culturally significant foundation from Denmark has reflected on - and legitimated - its work and investments at critical moments in the past decades. The paper indicates a foundation with a high degree of reflection on the wider societal...

  10. Mathematical foundations of biomechanics.

    Science.gov (United States)

    Niederer, Peter F

    2010-01-01

    The aim of biomechanics is the analysis of the structure and function of humans, animals, and plants by means of the methods of mechanics. Its foundations are in particular embedded in mathematics, physics, and informatics. Due to the inherent multidisciplinary character deriving from its aim, biomechanics has numerous connections and overlapping areas with biology, biochemistry, physiology, and pathophysiology, along with clinical medicine, so its range is enormously wide. This treatise is mainly meant to serve as an introduction and overview for readers and students who intend to acquire a basic understanding of the mathematical principles and mechanics that constitute the foundation of biomechanics; accordingly, its contents are limited to basic theoretical principles of general validity and long-range significance. Selected examples are included that are representative for the problems treated in biomechanics. Although ultimate mathematical generality is not in the foreground, an attempt is made to derive the theory from basic principles. A concise and systematic formulation is thereby intended with the aim that the reader is provided with a working knowledge. It is assumed that he or she is familiar with the principles of calculus, vector analysis, and linear algebra.

  11. Environmental Foundations in Germany

    Directory of Open Access Journals (Sweden)

    Thomas Krikser

    2015-05-01

    Full Text Available Foundations in Germany were examined in the context of environmental issues. Data from environmental foundations show that there is huge difference between private and public foundations concerning financial settings. Furthermore, environment is often not the only objective and sometimes not even processed. Our analysis shows that there are different types of foundations with regard to environmental scopes and activities. Although “attractive topics” such as biodiversity and landscape conservation seem to be more important to foundations, less visible topics such as pollution prevention remain merely a “blind spot.” Together, these findings suggest that there is only a limited potential of private foundations compared with public foundations. Nevertheless, there might be an impact on environmental awareness and local sustainability.

  12. Foundations of ionizing radiation dosimetry

    International Nuclear Information System (INIS)

    Denisenko, O.N.; Pereslegin, I.A.

    1985-01-01

    Foundations of dosimetry in application to radiotherapy are presented. General characteristics of ionizing radiations and main characteristics of ionizing radiation sources, mostly used in radiotherapy, are given. Values and units for measuring ionizing radiation (activity of a radioactive substance, absorbed dose, exposure dose, integral dose and dose equivalent are considered. Different methods and instruments for ionizing radiation dosimetry are discussed. The attention is paid to the foundations of clinical dosimetry (representation of anatomo-topographic information, choice of radiation conditions, realization of radiation methods, corrections for a configuration and inhomogeneity of a patient's body, account of biological factors of radiation effects, instruments of dose field formation, control of irradiation procedure chosen)

  13. Comparative study of finite element method, isogeometric analysis, and finite volume method in elastic wave propagation of stress discontinuities

    Czech Academy of Sciences Publication Activity Database

    Berezovski, A.; Kolman, Radek; Blažek, Jiří; Kopačka, Ján; Gabriel, Dušan; Plešek, Jiří

    2014-01-01

    Roč. 19, č. 12 (2014) ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] R&D Projects: GA ČR(CZ) GAP101/11/0288; GA ČR(CZ) GAP101/12/2315 Institutional support: RVO:61388998 Keywords : elastic wave propagation * finite element method * isogeometric analysis * finite volume method * stress discontinuities * spurious oscillations Subject RIV: JR - Other Machinery http://www.ndt.net/events/ECNDT2014/app/content/Paper/25_Berezovski_Rev1.pdf

  14. A self-sampling method to obtain large volumes of undiluted cervicovaginal secretions.

    Science.gov (United States)

    Boskey, Elizabeth R; Moench, Thomas R; Hees, Paul S; Cone, Richard A

    2003-02-01

    Studies of vaginal physiology and pathophysiology sometime require larger volumes of undiluted cervicovaginal secretions than can be obtained by current methods. A convenient method for self-sampling these secretions outside a clinical setting can facilitate such studies of reproductive health. The goal was to develop a vaginal self-sampling method for collecting large volumes of undiluted cervicovaginal secretions. A menstrual collection device (the Instead cup) was inserted briefly into the vagina to collect secretions that were then retrieved from the cup by centrifugation in a 50-ml conical tube. All 16 women asked to perform this procedure found it feasible and acceptable. Among 27 samples, an average of 0.5 g of secretions (range, 0.1-1.5 g) was collected. This is a rapid and convenient self-sampling method for obtaining relatively large volumes of undiluted cervicovaginal secretions. It should prove suitable for a wide range of assays, including those involving sexually transmitted diseases, microbicides, vaginal physiology, immunology, and pathophysiology.

  15. Flow simulation of a Pelton bucket using finite volume particle method

    International Nuclear Information System (INIS)

    Vessaz, C; Jahanbakhsh, E; Avellan, F

    2014-01-01

    The objective of the present paper is to perform an accurate numerical simulation of the high-speed water jet impinging on a Pelton bucket. To reach this goal, the Finite Volume Particle Method (FVPM) is used to discretize the governing equations. FVPM is an arbitrary Lagrangian-Eulerian method, which combines attractive features of Smoothed Particle Hydrodynamics and conventional mesh-based Finite Volume Method. This method is able to satisfy free surface and no-slip wall boundary conditions precisely. The fluid flow is assumed weakly compressible and the wall boundary is represented by one layer of particles located on the bucket surface. In the present study, the simulations of the flow in a stationary bucket are investigated for three different impinging angles: 72°, 90° and 108°. The particles resolution is first validated by a convergence study. Then, the FVPM results are validated with available experimental data and conventional grid-based Volume Of Fluid simulations. It is shown that the wall pressure field is in good agreement with the experimental and numerical data. Finally, the torque evolution and water sheet location are presented for a simulation of five rotating Pelton buckets

  16. Noninvasive measurement of cardiopulmonary blood volume: evaluation of the centroid method

    International Nuclear Information System (INIS)

    Fouad, F.M.; MacIntyre, W.J.; Tarazi, R.C.

    1981-01-01

    Cardiopulmonary blood volume (CPV) and mean pulmonary transit time (MTT) determined by radionuclide measurements (Tc-99m HSA) were compared with values obtained from simultaneous dye-dilution (DD) studies (indocyanine green). The mean transit time was obtained from radionuclide curves by two methods: the peak-to-peak time and the interval between the two centroids determined from the right and left-ventricular time-concentration curves. Correlation of dye-dilution MTT and peak-to-peak time was significant (r = 0.79, p < 0.001), but its correlation with centroid-derived values was better (r = 0.86, p < 0.001). CPV values (using the centroid method for radionuclide technique) correlated significantly with values derived from dye-dilution curves (r = 0.74, p < 0.001). Discrepancies between the two were greater the more rapid the circulation (r = 0.61, p < 0.01), suggesting that minor inaccuracies of dye-dilution methods, due to positioning or delay of the system, can become magnified in hyperkinetic conditions. The radionuclide method is simple, repeatable, and noninvasive, and it provides simultaneous evaluation of pulmonary and systemic hemodynamics. Further, calculation of the ratio of cardiopulmonary to total blood volume can be used as an index of overall venous distensibility and relocation of intravascular blood volume

  17. Characterization of hazardous waste sites: a methods manual. Volume 2. Available sampling methods (second edition)

    International Nuclear Information System (INIS)

    Ford, P.J.; Turina, P.J.; Seely, D.E.

    1984-12-01

    Investigations at hazardous waste sites and sites of chemical spills often require on-site measurements and sampling activities to assess the type and extent of contamination. This document is a compilation of sampling methods and materials suitable to address most needs that arise during routine waste site and hazardous spill investigations. The sampling methods presented in this document are compiled by media, and were selected on the basis of practicality, economics, representativeness, compatability with analytical considerations, and safety, as well as other criteria. In addition to sampling procedures, sample handling and shipping, chain-of-custody procedures, instrument certification, equipment fabrication, and equipment decontamination procedures are described. Sampling methods for soil, sludges, sediments, and bulk materials cover the solids medium. Ten methods are detailed for surface waters, groundwater and containerized liquids; twelve are presented for ambient air, soil gases and vapors, and headspace gases. A brief discussion of ionizing radiation survey instruments is also provided

  18. An enhanced finite volume method to model 2D linear elastic structures

    CSIR Research Space (South Africa)

    Suliman, Ridhwaan

    2014-04-01

    Full Text Available . Suliman) Preprint submitted to Applied Mathematical Modelling July 22, 2013 Keywords: finite volume, finite element, locking, error analysis 1. Introduction Since the 1960s, the finite element method has mainly been used for modelling the mechanics... formulation provides higher accuracy 2 for displacement solutions. It is well known that the linear finite element formulation suffers from sensitivity to element aspect ratio or shear locking when subjected to bend- ing [16]. Fallah [8] and Wheel [6] present...

  19. Application of the finite volume method in the simulation of saturated flows of binary mixtures

    International Nuclear Information System (INIS)

    Murad, M.A.; Gama, R.M.S. da; Sampaio, R.

    1989-12-01

    This work presents the simulation of saturated flows of an incompressible Newtonian fluid through a rigid, homogeneous and isotropic porous medium. The employed mathematical model is derived from the Continuum Theory of Mixtures and generalizes the classical one which is based on Darcy's Law form of the momentum equation. In this approach fluid and porous matrix are regarded as continuous constituents of a binary mixture. The finite volume method is employed in the simulation. (author) [pt

  20. Pressure-volume-temperature gauging method experiment using liquid nitrogen under microgravity condition of parabolic flight

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Man Su; Park, Hana; Yoo, Don Gyu; Jeong, Sang Kwon [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, KAIST, Daejeon (Korea, Republic of); Jung, Young Suk [Launcher Systems Development Team, Korea Aerospace Research Institute, Daejeon (Korea, Republic of)

    2014-06-15

    Measuring an exact amount of remaining cryogenic liquid propellant under microgravity condition is one of the important issues of rocket vehicle. A Pressure-Volume-Temperature (PVT) gauging method is attractive due to its minimal additional hardware and simple gauging process. In this paper, PVT gauging method using liquid nitrogen is investigated under microgravity condition with parabolic flight. A 9.2 litre metal cryogenic liquid storage tank containing approximately 30% of liquid nitrogen is pressurized by ambient temperature helium gas. During microgravity condition, the inside of the liquid tank becomes near-isothermal condition within 1 K difference indicated by 6 silicon diode sensors vertically distributed in the middle of the liquid tank. Helium injection with higher mass flow rate after 10 seconds of the waiting time results in successful measurements of helium partial pressure in the tank. Average liquid volume measurement error is within 11% of the whole liquid tank volume and standard deviation of errors is 11.9. As a result, the applicability of PVT gauging method to liquid.

  1. Pressure-volume-temperature gauging method experiment using liquid nitrogen under microgravity condition of parabolic flight

    International Nuclear Information System (INIS)

    Seo, Man Su; Park, Hana; Yoo, Don Gyu; Jeong, Sang Kwon; Jung, Young Suk

    2014-01-01

    Measuring an exact amount of remaining cryogenic liquid propellant under microgravity condition is one of the important issues of rocket vehicle. A Pressure-Volume-Temperature (PVT) gauging method is attractive due to its minimal additional hardware and simple gauging process. In this paper, PVT gauging method using liquid nitrogen is investigated under microgravity condition with parabolic flight. A 9.2 litre metal cryogenic liquid storage tank containing approximately 30% of liquid nitrogen is pressurized by ambient temperature helium gas. During microgravity condition, the inside of the liquid tank becomes near-isothermal condition within 1 K difference indicated by 6 silicon diode sensors vertically distributed in the middle of the liquid tank. Helium injection with higher mass flow rate after 10 seconds of the waiting time results in successful measurements of helium partial pressure in the tank. Average liquid volume measurement error is within 11% of the whole liquid tank volume and standard deviation of errors is 11.9. As a result, the applicability of PVT gauging method to liquid

  2. Optimization of radiation therapy, III: a method of assessing complication probabilities from dose-volume histograms

    International Nuclear Information System (INIS)

    Lyman, J.T.; Wolbarst, A.B.

    1987-01-01

    To predict the likelihood of success of a therapeutic strategy, one must be able to assess the effects of the treatment upon both diseased and healthy tissues. This paper proposes a method for determining the probability that a healthy organ that receives a non-uniform distribution of X-irradiation, heat, chemotherapy, or other agent will escape complications. Starting with any given dose distribution, a dose-cumulative-volume histogram for the organ is generated. This is then reduced by an interpolation scheme (involving the volume-weighting of complication probabilities) to a slightly different histogram that corresponds to the same overall likelihood of complications, but which contains one less step. The procedure is repeated, one step at a time, until there remains a final, single-step histogram, for which the complication probability can be determined. The formalism makes use of a complication response function C(D, V) which, for the given treatment schedule, represents the probability of complications arising when the fraction V of the organ receives dose D and the rest of the organ gets none. Although the data required to generate this function are sparse at present, it should be possible to obtain the necessary information from in vivo and clinical studies. Volume effects are taken explicitly into account in two ways: the precise shape of the patient's histogram is employed in the calculation, and the complication response function is a function of the volume

  3. A 3-D method for delineation of activity distributions and assessment of functional organ volumes with SPECT

    International Nuclear Information System (INIS)

    Wang, Y.; Karolinska Hospital and Karolinska Inst., Stockholm; Jacobsson, H.; Jacobson, S.H.; Kimiaei, S.; Larsson, S.A.

    1995-01-01

    The distrubution volume of an organ may have a clinical impact in many cases and various methods have been designed to make volume assessments. In this paper, we describe a new method for delineation of the distribution outline and volume determination. The method is based on smoothing, differentiation, image relaxation and voxel counting of single photon emission computer tomography (SPECT) image sets with 3-D operators. A special routine corrects for the inherent thickness of the voxel-based outline. Phantom experiments, using a SPECT system with LEGP-collimator and a 64x64 acquisition matrix with 6.3x6.3 mm 2 pixel size, demonstrated good correlation between the measured and the true volumes. For volumes larger than 120 cc the correlation coefficient was 0.9999 with SE 1.0 cc and an average relative deviation of 0.49%. For volumes below 120 cc, the accuracy was impaired due to low resolution power. By improving the system spatial resolution with an LEHR-collimator and a smaller pixel-size (4.1x4.1 mm 2 ), good accuracy was achieved also for volumes in the range from 3 to 120 cc. Measurements of 15 differently shaped phantoms of volumes between 3 and 104 cc demonstrated high correlation between measured and true volumes: R=0.9921 and SE=0.74 cc (5.3%). For volumes as small as 3 and 5 cc, the difference between the true and the assessed volume was 0.6 cc. The reproducibility of the method was within 3% for volumes above 120 cc and within 7% for volumes below. Due to this accuracy, we conclude that the method can be applied for various clinical routine and research applications using SPECT. (orig.)

  4. Report of a CSNI workshop on uncertainty analysis methods. Volume 1 + 2

    International Nuclear Information System (INIS)

    Wickett, A.J.; Yadigaroglu, G.

    1994-08-01

    The OECD NEA CSNI Principal Working Group 2 (PWG2) Task Group on Thermal Hydraulic System Behaviour (TGTHSB) has, in recent years, received presentations of a variety of different methods to analyze the uncertainty in the calculations of advanced unbiased (best estimate) codes. Proposals were also made for an International Standard Problem (ISP) to compare the uncertainty analysis methods. The objectives for the Workshop were to discuss and fully understand the principles of uncertainty analysis relevant to LOCA modelling and like problems, to examine the underlying issues from first principles, in preference to comparing and contrasting the currently proposed methods, to reach consensus on the issues identified as far as possible while not avoiding the controversial aspects, to identify as clearly as possible unreconciled differences, and to issue a Status Report. Eight uncertainty analysis methods were presented. A structured discussion of various aspects of uncertainty analysis followed - the need for uncertainty analysis, identification and ranking of uncertainties, characterisation, quantification and combination of uncertainties and applications, resources and future developments. As a result, the objectives set out above were, to a very large extent, achieved. Plans for the ISP were also discussed. Volume 1 contains a record of the discussions on uncertainty methods. Volume 2 is a compilation of descriptions of the eight uncertainty analysis methods presented at the workshop

  5. A point-value enhanced finite volume method based on approximate delta functions

    Science.gov (United States)

    Xuan, Li-Jun; Majdalani, Joseph

    2018-02-01

    We revisit the concept of an approximate delta function (ADF), introduced by Huynh (2011) [1], in the form of a finite-order polynomial that holds identical integral properties to the Dirac delta function when used in conjunction with a finite-order polynomial integrand over a finite domain. We show that the use of generic ADF polynomials can be effective at recovering and generalizing several high-order methods, including Taylor-based and nodal-based Discontinuous Galerkin methods, as well as the Correction Procedure via Reconstruction. Based on the ADF concept, we then proceed to formulate a Point-value enhanced Finite Volume (PFV) method, which stores and updates the cell-averaged values inside each element as well as the unknown quantities and, if needed, their derivatives on nodal points. The sharing of nodal information with surrounding elements saves the number of degrees of freedom compared to other compact methods at the same order. To ensure conservation, cell-averaged values are updated using an identical approach to that adopted in the finite volume method. Here, the updating of nodal values and their derivatives is achieved through an ADF concept that leverages all of the elements within the domain of integration that share the same nodal point. The resulting scheme is shown to be very stable at successively increasing orders. Both accuracy and stability of the PFV method are verified using a Fourier analysis and through applications to the linear wave and nonlinear Burgers' equations in one-dimensional space.

  6. Does Categorization Method Matter in Exploring Volume-Outcome Relation? A Multiple Categorization Methods Comparison in Coronary Artery Bypass Graft Surgery Surgical Site Infection.

    Science.gov (United States)

    Yu, Tsung-Hsien; Tung, Yu-Chi; Chung, Kuo-Piao

    2015-08-01

    Volume-infection relation studies have been published for high-risk surgical procedures, although the conclusions remain controversial. Inconsistent results may be caused by inconsistent categorization methods, the definitions of service volume, and different statistical approaches. The purpose of this study was to examine whether a relation exists between provider volume and coronary artery bypass graft (CABG) surgical site infection (SSI) using different categorization methods. A population-based cross-sectional multi-level study was conducted. A total of 10,405 patients who received CABG surgery between 2006 and 2008 in Taiwan were recruited. The outcome of interest was surgical site infection for CABG surgery. The associations among several patient, surgeon, and hospital characteristics was examined. The definition of surgeons' and hospitals' service volume was the cumulative CABG service volumes in the previous year for each CABG operation and categorized by three types of approaches: Continuous, quartile, and k-means clustering. The results of multi-level mixed effects modeling showed that hospital volume had no association with SSI. Although the relation between surgeon volume and surgical site infection was negative, it was inconsistent among the different categorization methods. Categorization of service volume is an important issue in volume-infection study. The findings of the current study suggest that different categorization methods might influence the relation between volume and SSI. The selection of an optimal cutoff point should be taken into account for future research.

  7. Semiautomatic volume of interest drawing for 18F-FDG image analysis - method and preliminary results

    International Nuclear Information System (INIS)

    Green, A.J.; Baig, S.; Begent, R.H.J.; Francis, R.J.

    2008-01-01

    Functional imaging of cancer adds important information to the conventional measurements in monitoring response. Serial 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET), which indicates changes in glucose metabolism in tumours, shows great promise for this. However, there is a need for a method to quantitate alterations in uptake of FDG, which accounts for changes in tumour volume and intensity of FDG uptake. Selection of regions or volumes [ROI or volumes of interest (VOI)] by hand drawing, or simple thresholding, suffers from operator-dependent drawbacks. We present a simple, robust VOI growing method for this application. The method requires a single seed point within the visualised tumour and another in relevant normal tissue. The drawn tumour VOI is insensitive to the operator inconsistency and is, thus, a suitable basis for comparative measurements. The method is validated using a software phantom. We demonstrate the use of the method in the assessment of tumour response in 31 patients receiving chemotherapy for various carcinomas. Valid assessment of tumour response could be made 2-4 weeks after starting chemotherapy, giving information for clinical decision making which would otherwise have taken 9-12 weeks. Survival was predicted from FDG-PET 2-4 weeks after starting chemotherapy (p = 0.04) and after 9-12 weeks FDG-PET gave a better prediction of survival (p = 0.002) than CT or MRI (p = 0.015). FDG-PET using this method of analysis has potential as a routine tool for optimising use of chemotherapy and improving its cost effectiveness. It also has potential for increasing the accuracy of response assessment in clinical trials of novel therapies. (orig.)

  8. Shells on elastic foundations

    International Nuclear Information System (INIS)

    Das, Y.C.; Kedia, K.K.

    1977-01-01

    No realistic analytical work in the area of Shells on Elastic Foundations has been reported in the literature. Various foundation models have been proposed by several authors. These models involve one or more than one parameters to characterise the foundation medium. Some of these models cannot be used to derive the basic equations governing the behaviour of shells on elastic foundations. In the present work, starting from an elastic continuum hypothesis, a mathematical model for foundation has been derived in curvilinear orthogonal coordinates by the help of principle of virtual displacements, treating one of the virtual displacements as known to satisfy certain given conditions at its edge surfaces. In this model, several foundation parameters can be considered and it can also be used for layered medium of both finite and infinite thickness. (Auth.)

  9. A comparative study of lattice Boltzmann and volume of fluid method for two dimensional multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Seung Yeob [Korea Atomic Energy Research Institute (KAERI), Daejeon (Korea, Republic of); Ko, Sung Ho [Dept. of Mechanical Design Engineering, Chungnam National University, Daejeon (Korea, Republic of)

    2012-08-15

    The volume of fluid (VOF) model of FLUENT and the lattice Boltzmann method (LBM) are used to simulate two-phase flows. Both methods are validated for static and dynamic bubble test cases and then compared to experimental results. The VOF method does not reduce the spurious currents of the static droplet test and does not satisfy the Laplace law for small droplets at the acceptable level, as compared with the LBM. For single bubble flows, simulations are executed for various Eotvos numbers, Morton numbers and Reynolds numbers, and the results of both methods agree well with the experiments in the case of low Eotvos numbers. For high Eotvos numbers, the VOF results deviated from the experiments. For multiple bubbles, the bubble flow characteristics are related by the wake of the leading bubble. The coaxial and oblique coalescence of the bubbles are simulated successfully and the subsequent results are presented. In conclusion, the LBM performs better than the VOF method.

  10. Extrusion Process by Finite Volume Method Using OpenFoam Software

    International Nuclear Information System (INIS)

    Matos Martins, Marcelo; Tonini Button, Sergio; Divo Bressan, Jose; Ivankovic, Alojz

    2011-01-01

    The computational codes are very important tools to solve engineering problems. In the analysis of metal forming process, such as extrusion, this is not different because the computational codes allow analyzing the process with reduced cost. Traditionally, the Finite Element Method is used to solve solid mechanic problems, however, the Finite Volume Method (FVM) have been gaining force in this field of applications. This paper presents the velocity field and friction coefficient variation results, obtained by numerical simulation using the OpenFoam Software and the FVM to solve an aluminum direct cold extrusion process.

  11. Hanford environmental analytical methods: Methods as of March 1990. Volume 3, Appendix A2-I

    Energy Technology Data Exchange (ETDEWEB)

    Goheen, S.C.; McCulloch, M.; Daniel, J.L.

    1993-05-01

    This paper from the analytical laboratories at Hanford describes the method used to measure pH of single-shell tank core samples. Sludge or solid samples are mixed with deionized water. The pH electrode used combines both a sensor and reference electrode in one unit. The meter amplifies the input signal from the electrode and displays the pH visually.

  12. Relationship between CT visual score and lung volume which is measured by helium dilution method and body plethysmographic method in patients with pulmonary emphysema

    International Nuclear Information System (INIS)

    Toyoshima, Hideo; Ishibashi, Masayoshi; Senju, Syoji; Tanaka, Hideki; Aritomi, Takamichi; Watanabe, Kentaro; Yoshida, Minoru

    1997-01-01

    We examined the relationship between CT visual score and pulmonary function studies in patients with pulmonary emphysema. Lung volume was measured using helium dilution method and body plethysmographic method. Although airflow obstruction and overinflation measured by helium dilution method did not correlate with CT visual score, CO diffusing capacity per alveolar volume (DL CO /V A ) showed significant negative correlation with CT visual score (r=-0.49, p CO /V A reflect pathologic change in pulmonary emphysema. Further, both helium dilution method and body plethysmographic method are required to evaluate lung volume of pulmonary emphysema because of its ventilatory unevenness. (author)

  13. Non Machinable Volume Calculation Method for 5-Axis Roughing Based on Faceted Models through Closed Bounded Area Evaluation

    Directory of Open Access Journals (Sweden)

    Kiswanto Gandjar

    2017-01-01

    Full Text Available The increase in the volume of rough machining on the CBV area is one of the indicators of increased efficiencyof machining process. Normally, this area is not subject to the rough machining process, so that the volume of the rest of the material is still big. With the addition of CC point and tool orientation to CBV area on a complex surface, the finishing will be faster because the volume of the excess material on this process will be reduced. This paper presents a method for volume calculation of the parts which do not allow further occurrence of the machining process, particulary for rough machining on a complex object. By comparing the total volume of raw materials and machining area volume, the volume of residual material,on which machining process cannot be done,can be determined. The volume of the total machining area has been taken into account for machiningof the CBV and non CBV areas. By using delaunay triangulation for the triangle which includes the machining and CBV areas. The volume will be calculated using Divergence(Gaussian theorem by focusing on the direction of the normal vector on each triangle. This method can be used as an alternative to selecting tothe rough machining methods which select minimum value of nonmachinable volume so that effectiveness can be achieved in the machining process.

  14. Predicting uncertainty in future marine ice sheet volume using Bayesian statistical methods

    Science.gov (United States)

    Davis, A. D.

    2015-12-01

    The marine ice instability can trigger rapid retreat of marine ice streams. Recent observations suggest that marine ice systems in West Antarctica have begun retreating. However, unknown ice dynamics, computationally intensive mathematical models, and uncertain parameters in these models make predicting retreat rate and ice volume difficult. In this work, we fuse current observational data with ice stream/shelf models to develop probabilistic predictions of future grounded ice sheet volume. Given observational data (e.g., thickness, surface elevation, and velocity) and a forward model that relates uncertain parameters (e.g., basal friction and basal topography) to these observations, we use a Bayesian framework to define a posterior distribution over the parameters. A stochastic predictive model then propagates uncertainties in these parameters to uncertainty in a particular quantity of interest (QoI)---here, the volume of grounded ice at a specified future time. While the Bayesian approach can in principle characterize the posterior predictive distribution of the QoI, the computational cost of both the forward and predictive models makes this effort prohibitively expensive. To tackle this challenge, we introduce a new Markov chain Monte Carlo method that constructs convergent approximations of the QoI target density in an online fashion, yielding accurate characterizations of future ice sheet volume at significantly reduced computational cost.Our second goal is to attribute uncertainty in these Bayesian predictions to uncertainties in particular parameters. Doing so can help target data collection, for the purpose of constraining the parameters that contribute most strongly to uncertainty in the future volume of grounded ice. For instance, smaller uncertainties in parameters to which the QoI is highly sensitive may account for more variability in the prediction than larger uncertainties in parameters to which the QoI is less sensitive. We use global sensitivity

  15. A novel finite volume discretization method for advection-diffusion systems on stretched meshes

    Science.gov (United States)

    Merrick, D. G.; Malan, A. G.; van Rooyen, J. A.

    2018-06-01

    This work is concerned with spatial advection and diffusion discretization technology within the field of Computational Fluid Dynamics (CFD). In this context, a novel method is proposed, which is dubbed the Enhanced Taylor Advection-Diffusion (ETAD) scheme. The model equation employed for design of the scheme is the scalar advection-diffusion equation, the industrial application being incompressible laminar and turbulent flow. Developed to be implementable into finite volume codes, ETAD places specific emphasis on improving accuracy on stretched structured and unstructured meshes while considering both advection and diffusion aspects in a holistic manner. A vertex-centered structured and unstructured finite volume scheme is used, and only data available on either side of the volume face is employed. This includes the addition of a so-called mesh stretching metric. Additionally, non-linear blending with the existing NVSF scheme was performed in the interest of robustness and stability, particularly on equispaced meshes. The developed scheme is assessed in terms of accuracy - this is done analytically and numerically, via comparison to upwind methods which include the popular QUICK and CUI techniques. Numerical tests involved the 1D scalar advection-diffusion equation, a 2D lid driven cavity and turbulent flow case. Significant improvements in accuracy were achieved, with L2 error reductions of up to 75%.

  16. An efficicient data structure for three-dimensional vertex based finite volume method

    Science.gov (United States)

    Akkurt, Semih; Sahin, Mehmet

    2017-11-01

    A vertex based three-dimensional finite volume algorithm has been developed using an edge based data structure.The mesh data structure of the given algorithm is similar to ones that exist in the literature. However, the data structures are redesigned and simplied in order to fit requirements of the vertex based finite volume method. In order to increase the cache efficiency, the data access patterns for the vertex based finite volume method are investigated and these datas are packed/allocated in a way that they are close to each other in the memory. The present data structure is not limited with tetrahedrons, arbitrary polyhedrons are also supported in the mesh without putting any additional effort. Furthermore, the present data structure also supports adaptive refinement and coarsening. For the implicit and parallel implementation of the FVM algorithm, PETSc and MPI libraries are employed. The performance and accuracy of the present algorithm are tested for the classical benchmark problems by comparing the CPU time for the open source algorithms.

  17. Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volume

    International Nuclear Information System (INIS)

    Malkov, Serghei; Wang, Jeff; Kerlikowske, Karla; Cummings, Steven R.; Shepherd, John A.

    2009-01-01

    Purpose: This study describes the design and characteristics of a highly accurate, precise, and automated single-energy method to quantify percent fibroglandular tissue volume (%FGV) and fibroglandular tissue volume (FGV) using digital screening mammography. Methods: The method uses a breast tissue-equivalent phantom in the unused portion of the mammogram as a reference to estimate breast composition. The phantom is used to calculate breast thickness and composition for each image regardless of x-ray technique or the presence of paddle tilt. The phantom adheres to the top of the mammographic compression paddle and stays in place for both craniocaudal and mediolateral oblique screening views. We describe the automated method to identify the phantom and paddle orientation with a three-dimensional reconstruction least-squares technique. A series of test phantoms, with a breast thickness range of 0.5-8 cm and a %FGV of 0%-100%, were made to test the accuracy and precision of the technique. Results: Using test phantoms, the estimated repeatability standard deviation equaled 2%, with a ±2% accuracy for the entire thickness and density ranges. Without correction, paddle tilt was found to create large errors in the measured density values of up to 7%/mm difference from actual breast thickness. This new density measurement is stable over time, with no significant drifts in calibration noted during a four-month period. Comparisons of %FGV to mammographic percent density and left to right breast %FGV were highly correlated (r=0.83 and 0.94, respectively). Conclusions: An automated method for quantifying fibroglandular tissue volume has been developed. It exhibited good accuracy and precision for a broad range of breast thicknesses, paddle tilt angles, and %FGV values. Clinical testing showed high correlation to mammographic density and between left and right breasts.

  18. Uncertainty associated with assessing semen volume: are volumetric and gravimetric methods that different?

    Science.gov (United States)

    Woodward, Bryan; Gossen, Nicole; Meadows, Jessica; Tomlinson, Mathew

    2016-12-01

    The World Health Organization laboratory manual for the examination of human semen suggests that an indirect measurement of semen volume by weighing (gravimetric method) is more accurate than a direct measure using a serological pipette. A series of experiments were performed to determine the level of discrepancy between the two methods using pipettes and a balance which had been calibrated to a traceable standard. The median weights of 1.0ml and 5.0ml of semen were 1.03 g (range 1.02-1.05 g) and 5.11 g (range 4.95-5.16 g), respectively, suggesting a density for semen between 1.03g and 1.04 g/ml. When the containers were re-weighed after the removal of 5.0 ml semen using a serological pipette, the mean residual loss was 0.12 ml (120 μl) or 0.12 g (median 100 μl, range 70-300 μl). Direct comparison of the volumetric and gravimetric methods in a total of 40 samples showed a mean difference of 0.25ml (median 0.32 ± 0.67ml) representing an error of 8.5%. Residual semen left in the container by weight was on average 0.11 g (median 0.10 g, range 0.05-0.19 g). Assuming a density of 1 g/ml then the average error between volumetric and gravimetric methods was approximately 8% (p gravimetric measurement of semen volume. Laboratories may therefore prefer to provide in-house quality assurance data in order to be satisfied that 'estimating' semen volume is 'fit for purpose' as opposed to assuming a lower uncertainty associated with the WHO recommended method.

  19. Profiles of Nine Community Colleges with Successful Foundations.

    Science.gov (United States)

    Angel, Dan; Gares, Dale

    1981-01-01

    College profiles include the following information: type of college, location, enrollment, age of college, total budget, foundation's years of experience, non-profit status, total foundation assets, dollar support for 1979-80, responsibility for foundation, number of foundation board members, most successful fund-raising methods, and restrictions…

  20. Monte Carlo method for critical systems in infinite volume: The planar Ising model.

    Science.gov (United States)

    Herdeiro, Victor; Doyon, Benjamin

    2016-10-01

    In this paper we propose a Monte Carlo method for generating finite-domain marginals of critical distributions of statistical models in infinite volume. The algorithm corrects the problem of the long-range effects of boundaries associated to generating critical distributions on finite lattices. It uses the advantage of scale invariance combined with ideas of the renormalization group in order to construct a type of "holographic" boundary condition that encodes the presence of an infinite volume beyond it. We check the quality of the distribution obtained in the case of the planar Ising model by comparing various observables with their infinite-plane prediction. We accurately reproduce planar two-, three-, and four-point of spin and energy operators. We also define a lattice stress-energy tensor, and numerically obtain the associated conformal Ward identities and the Ising central charge.

  1. Characteristic Behavior of Bucket Foundations

    DEFF Research Database (Denmark)

    Barari, Amin

    political and industrial forces(particularly in northern Europe) supporting the development of the offshore wind industry. The overall aim of the research presented in this thesis was to improve the design of offshore wind turbine foundations. The work was divided into two main researchefforts: geotechnical...... reduce the risks and costsrelated to offshore geotechnics. The thesis examines: 1.Characteristic Behavior of Bucket Foundations 2. Modeling of Water Flow through Porous Media The outcomes of each of the research contributions are summarized in four research articles, either directly or indirectly...... engineering experiments to gain insight into the behavior of offshore bucket foundations, and development of methods to improve the study of infiltration intounsaturated soils, an important problem in geo-environmental engineering. The outcomes of the research have the potential to directly or indirectly...

  2. Clinical determination of the volume of the neurocranium in infancy. A presentation of two new methods.

    Science.gov (United States)

    Mösch, D; Mösch, H P; Kaiser, G

    1983-05-01

    Two useful methods for the exact volumetric measurement of the neurocranium are introduced. Using these methods in a transversal study, mean ratio and range for normal boys and girls from birth to six months can be defined. Longitudinal studies and comparative literature research confirm the accuracy of these standard values. The application to pathological cases shows that hypogenesis of the neurocranium can be recognized earlier and more accurately by measuring the volume than by measuring the circumference of the head. Both methods are easy to apply and can be expected of every child. However, method B (dipping in the neurocranium and measuring the displaced water on a scale) has proved to be more accurate, simpler and faster.

  3. Precision of a new bedside method for estimation of the circulating blood volume

    DEFF Research Database (Denmark)

    Christensen, P; Eriksen, B; Henneberg, S W

    1993-01-01

    The present study is a theoretical and experimental evaluation of a modification of the carbon monoxide method for estimation of the circulating blood volume (CBV) with respect to the precision of the method. The CBV was determined from measurements of the CO-saturation of hemoglobin before...... ventilation with the CO gas mixture. The amount of CO administered during each determination of CBV resulted in an increase in the CO saturation of hemoglobin of 2.1%-3.9%. A theoretical noise propagation analysis was performed by means of the Monte Carlo method. The analysis showed that a CO dose...... patients. The coefficients of variation were 6.2% and 4.7% in healthy and diseased subjects, respectively. Furthermore, the day-to-day variation of the method with respect to the total amount of circulating hemoglobin (nHb) and CBV was determined from duplicate estimates separated by 24-48 h. In conclusion...

  4. Numerical simulation of bubble deformation in magnetic fluids by finite volume method

    International Nuclear Information System (INIS)

    Yamasaki, Haruhiko; Yamaguchi, Hiroshi

    2017-01-01

    Bubble deformation in magnetic fluids under magnetic field is investigated numerically by an interface capturing method. The numerical method consists of a coupled level-set and VOF (Volume of Fluid) method, combined with conservation CIP (Constrained Interpolation Profile) method with the self-correcting procedure. In the present study considering actual physical properties of magnetic fluid, bubble deformation under given uniform magnetic field is analyzed for internal magnetic field passing through a magnetic gaseous and liquid phase interface. The numerical results explain the mechanism of bubble deformation under presence of given magnetic field. - Highlights: • A magnetic field analysis is developed to simulate the bubble dynamics in magnetic fluid with two-phase interface. • The elongation of bubble increased with increasing magnetic flux intensities due to strong magnetic normal force. • Proposed technique explains the bubble dynamics, taking into account of the continuity of the magnetic flux density.

  5. Evaluation of methods for MR imaging of human right ventricular heart volumes and mass

    International Nuclear Information System (INIS)

    Jauhiainen, T.; Jaervinen, V.M.; Hekali, P.E.

    2002-01-01

    Purpose: To assess the utility of two different imaging directions in the evaluation of human right ventricular (RV) heart volumes and mass with MR imaging; to compare breath-hold vs. non-breath-hold imaging in volume analysis; and to compare turbo inversion recovery imaging (TIR) with gradient echo imaging in RV mass measurement. Material and Methods: We examined 12 healthy volunteers (age 27-59 years). Breath-hold gradient echo MR imaging was performed in two imaging planes: 1) perpendicular to the RV inflow tract (RVIT view), and 2) in the transaxial view (TA view). The imaging was repeated in the TA view while the subjects were breathing freely. To analyze RV mass using TIR images, the RV was again imaged at end-diastole using the two views. The RV end-diastolic cavity (RVEDV) and muscle volume as well as end-systolic cavity volume (RVESV) were determined with the method of discs. All measurements were done blindly twice to assess repeatability of image analysis. To assess reproducibility of the measurements, 6 of the subjects were imaged twice at an interval of 5-9 weeks. Results: RVEDV averaged 133.2 ml, RVESV 61.5 ml and the RVmass 46.2 g in the RVIT view and 119.9 ml, 56.9 ml and 38.3 g in the TA view, respectively. The volumes obtained with breath-holding were slightly but not significantly smaller than the volumes obtained during normal breathing. There were no marked differences in the RV muscle mass obtained with gradient echo imaging compared to TIR imaging in either views. Repeatability of volume analysis was better in TA than RVIT view: the mean differences were 0.7±4.0 ml and 5.4±14.0 ml in end-diastole and 1.6±3.1 ml and 1.5±13.9 ml in end-systole, respectively. Repeatability of mass analysis was good in both TIR and cine images in the RVIT view but slightly better in TIR images: 0.5±2.4 g compared to 0.8±2.9 g in cine images. Reproducibility of imaging was good, mean differences for RVEDV and RVESV were 1.0±4.8 ml and 0.8±2.8 ml

  6. Evaluation of bias-correction methods for ensemble streamflow volume forecasts

    Directory of Open Access Journals (Sweden)

    T. Hashino

    2007-01-01

    Full Text Available Ensemble prediction systems are used operationally to make probabilistic streamflow forecasts for seasonal time scales. However, hydrological models used for ensemble streamflow prediction often have simulation biases that degrade forecast quality and limit the operational usefulness of the forecasts. This study evaluates three bias-correction methods for ensemble streamflow volume forecasts. All three adjust the ensemble traces using a transformation derived with simulated and observed flows from a historical simulation. The quality of probabilistic forecasts issued when using the three bias-correction methods is evaluated using a distributions-oriented verification approach. Comparisons are made of retrospective forecasts of monthly flow volumes for a north-central United States basin (Des Moines River, Iowa, issued sequentially for each month over a 48-year record. The results show that all three bias-correction methods significantly improve forecast quality by eliminating unconditional biases and enhancing the potential skill. Still, subtle differences in the attributes of the bias-corrected forecasts have important implications for their use in operational decision-making. Diagnostic verification distinguishes these attributes in a context meaningful for decision-making, providing criteria to choose among bias-correction methods with comparable skill.

  7. Angular finite volume method for solving the multigroup transport equation with piecewise average scattering cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Calloo, A.; Vidal, J.F.; Le Tellier, R.; Rimpault, G., E-mail: ansar.calloo@cea.fr, E-mail: jean-francois.vidal@cea.fr, E-mail: romain.le-tellier@cea.fr, E-mail: gerald.rimpault@cea.fr [CEA, DEN, DER/SPRC/LEPh, Saint-Paul-lez-Durance (France)

    2011-07-01

    This paper deals with the solving of the multigroup integro-differential form of the transport equation for fine energy group structure. In that case, multigroup transfer cross sections display strongly peaked shape for light scatterers and the current Legendre polynomial expansion is not well-suited to represent them. Furthermore, even if considering an exact scattering cross sections representation, the scattering source in the discrete ordinates method (also known as the Sn method) being calculated by sampling the angular flux at given directions, may be wrongly computed due to lack of angular support for the angular flux. Hence, following the work of Gerts and Matthews, an angular finite volume solver has been developed for 2D Cartesian geometries. It integrates the multigroup transport equation over discrete volume elements obtained by meshing the unit sphere with a product grid over the polar and azimuthal coordinates and by considering the integrated flux per solid angle element. The convergence of this method has been compared to the S{sub n} method for a highly anisotropic benchmark. Besides, piecewise-average scattering cross sections have been produced for non-bound Hydrogen atoms using a free gas model for thermal neutrons. LWR lattice calculations comparing Legendre representations of the Hydrogen scattering multigroup cross section at various orders and piecewise-average cross sections for this same atom are carried out (while keeping a Legendre representation for all other isotopes). (author)

  8. Angular finite volume method for solving the multigroup transport equation with piecewise average scattering cross sections

    International Nuclear Information System (INIS)

    Calloo, A.; Vidal, J.F.; Le Tellier, R.; Rimpault, G.

    2011-01-01

    This paper deals with the solving of the multigroup integro-differential form of the transport equation for fine energy group structure. In that case, multigroup transfer cross sections display strongly peaked shape for light scatterers and the current Legendre polynomial expansion is not well-suited to represent them. Furthermore, even if considering an exact scattering cross sections representation, the scattering source in the discrete ordinates method (also known as the Sn method) being calculated by sampling the angular flux at given directions, may be wrongly computed due to lack of angular support for the angular flux. Hence, following the work of Gerts and Matthews, an angular finite volume solver has been developed for 2D Cartesian geometries. It integrates the multigroup transport equation over discrete volume elements obtained by meshing the unit sphere with a product grid over the polar and azimuthal coordinates and by considering the integrated flux per solid angle element. The convergence of this method has been compared to the S_n method for a highly anisotropic benchmark. Besides, piecewise-average scattering cross sections have been produced for non-bound Hydrogen atoms using a free gas model for thermal neutrons. LWR lattice calculations comparing Legendre representations of the Hydrogen scattering multigroup cross section at various orders and piecewise-average cross sections for this same atom are carried out (while keeping a Legendre representation for all other isotopes). (author)

  9. Simulation of Jetting in Injection Molding Using a Finite Volume Method

    Directory of Open Access Journals (Sweden)

    Shaozhen Hua

    2016-05-01

    Full Text Available In order to predict the jetting and the subsequent buckling flow more accurately, a three dimensional melt flow model was established on a viscous, incompressible, and non-isothermal fluid, and a control volume-based finite volume method was employed to discretize the governing equations. A two-fold iterative method was proposed to decouple the dependence among pressure, velocity, and temperature so as to reduce the computation and improve the numerical stability. Based on the proposed theoretical model and numerical method, a program code was developed to simulate melt front progress and flow fields. The numerical simulations for different injection speeds, melt temperatures, and gate locations were carried out to explore the jetting mechanism. The results indicate the filling pattern depends on the competition between inertial and viscous forces. When inertial force exceeds the viscous force jetting occurs, then it changes to a buckling flow as the viscous force competes over the inertial force. Once the melt contacts with the mold wall, the melt filling switches to conventional sequential filling mode. Numerical results also indicate jetting length increases with injection speed but changes little with melt temperature. The reasonable agreements between simulated and experimental jetting length and buckling frequency imply the proposed method is valid for jetting simulation.

  10. Brachytherapy dose-volume histogram computations using optimized stratified sampling methods

    International Nuclear Information System (INIS)

    Karouzakis, K.; Lahanas, M.; Milickovic, N.; Giannouli, S.; Baltas, D.; Zamboglou, N.

    2002-01-01

    A stratified sampling method for the efficient repeated computation of dose-volume histograms (DVHs) in brachytherapy is presented as used for anatomy based brachytherapy optimization methods. The aim of the method is to reduce the number of sampling points required for the calculation of DVHs for the body and the PTV. From the DVHs are derived the quantities such as Conformity Index COIN and COIN integrals. This is achieved by using partial uniform distributed sampling points with a density in each region obtained from a survey of the gradients or the variance of the dose distribution in these regions. The shape of the sampling regions is adapted to the patient anatomy and the shape and size of the implant. For the application of this method a single preprocessing step is necessary which requires only a few seconds. Ten clinical implants were used to study the appropriate number of sampling points, given a required accuracy for quantities such as cumulative DVHs, COIN indices and COIN integrals. We found that DVHs of very large tissue volumes surrounding the PTV, and also COIN distributions, can be obtained using a factor of 5-10 times smaller the number of sampling points in comparison with uniform distributed points

  11. Establishing a University Foundation.

    Science.gov (United States)

    Lemish, Donald L.

    A handbook on how to establish a university foundation is presented. It presupposes that a foundation will be used as the umbrella organization for receiving all private gifts, restricted and unrestricted, for the benefit of a public college or university; and hence it chiefly addresses readers from public colleges and universities. Information is…

  12. Foundations for Critical Thinking

    Science.gov (United States)

    Bers, Trudy; Chun, Marc; Daly, William T.; Harrington, Christine; Tobolowsky, Barbara F.

    2015-01-01

    "Foundations for Critical Thinking" explores the landscape of critical-thinking skill development and pedagogy through foundational chapters and institutional case studies involving a range of students in diverse settings. By establishing a link between active learning and improved critical thinking, this resource encourages all higher…

  13. Modelling Foundations and Applications

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 8th European Conference on Modelling Foundations and Applications, held in Kgs. Lyngby, Denmark, in July 2012. The 20 revised full foundations track papers and 10 revised full applications track papers presented were carefully reviewed...

  14. The Monopod Bucket Foundation

    DEFF Research Database (Denmark)

    Bakmar, Christian LeBlanc; Ahle, Kim; Nielsen, Søren A.

    2009-01-01

    Following the successful installation of a prototype of a monopod bucket foundation, also called a “monopod suction caisson”, at Horns Rev 2 Offshore Wind Farm, Denmark, in 2009, DONG Energy is currently developing a commercialization strategy. The monopod bucket foundation is a promising...

  15. The Jan Korec Foundation

    International Nuclear Information System (INIS)

    2007-01-01

    In this video-film activities of the the Jan Korec Foundation are presented. The Jan Korec Foundation supports students of technical sciences, sport activities, science and support of book publishing, humanitarian supports, the environment protection as well as support of different social projects.

  16. Evaluation of two-phase flow solvers using Level Set and Volume of Fluid methods

    Science.gov (United States)

    Bilger, C.; Aboukhedr, M.; Vogiatzaki, K.; Cant, R. S.

    2017-09-01

    Two principal methods have been used to simulate the evolution of two-phase immiscible flows of liquid and gas separated by an interface. These are the Level-Set (LS) method and the Volume of Fluid (VoF) method. Both methods attempt to represent the very sharp interface between the phases and to deal with the large jumps in physical properties associated with it. Both methods have their own strengths and weaknesses. For example, the VoF method is known to be prone to excessive numerical diffusion, while the basic LS method has some difficulty in conserving mass. Major progress has been made in remedying these deficiencies, and both methods have now reached a high level of physical accuracy. Nevertheless, there remains an issue, in that each of these methods has been developed by different research groups, using different codes and most importantly the implementations have been fine tuned to tackle different applications. Thus, it remains unclear what are the remaining advantages and drawbacks of each method relative to the other, and what might be the optimal way to unify them. In this paper, we address this gap by performing a direct comparison of two current state-of-the-art variations of these methods (LS: RCLSFoam and VoF: interPore) and implemented in the same code (OpenFoam). We subject both methods to a pair of benchmark test cases while using the same numerical meshes to examine a) the accuracy of curvature representation, b) the effect of tuning parameters, c) the ability to minimise spurious velocities and d) the ability to tackle fluids with very different densities. For each method, one of the test cases is chosen to be fairly benign while the other test case is expected to present a greater challenge. The results indicate that both methods can be made to work well on both test cases, while displaying different sensitivity to the relevant parameters.

  17. Direct and indirect methods for the quantification of leg volume: Comparison between water displacement volumetry, the disk model method and the frustum sign model method, using the correlation coefficient and the limits of agreement

    NARCIS (Netherlands)

    D.M.K.S. Kaulesar Sukul (D. M K S); P.Th. den Hoed (Pieter); T. Johannes (Tanja); R. van Dolder (R.); E. Benda (Eric)

    1993-01-01

    textabstractVolume changes can be measured either directly by water-displacement volumetry or by various indirect methods in which calculation of the volume is based on circumference measurements. The aim of the present study was to determine the most appropriate indirect method for lower leg volume

  18. Linear programming foundations and extensions

    CERN Document Server

    Vanderbei, Robert J

    2001-01-01

    Linear Programming: Foundations and Extensions is an introduction to the field of optimization. The book emphasizes constrained optimization, beginning with a substantial treatment of linear programming, and proceeding to convex analysis, network flows, integer programming, quadratic programming, and convex optimization. The book is carefully written. Specific examples and concrete algorithms precede more abstract topics. Topics are clearly developed with a large number of numerical examples worked out in detail. Moreover, Linear Programming: Foundations and Extensions underscores the purpose of optimization: to solve practical problems on a computer. Accordingly, the book is coordinated with free efficient C programs that implement the major algorithms studied: -The two-phase simplex method; -The primal-dual simplex method; -The path-following interior-point method; -The homogeneous self-dual methods. In addition, there are online JAVA applets that illustrate various pivot rules and variants of the simplex m...

  19. Experimental studies for the development of a new method for stroke volume measuring using X-ray videodensitometry

    International Nuclear Information System (INIS)

    Odenthal, H.J.

    1982-01-01

    Quantitative videodensitometry was studied with a view to its possible application as a new, non-invasive method of measuring cardiac stroke volume. To begin with, the accuracy of roentgen volumetric measurements was determined. After this, blood volume variations were measured by densitometry in five animal experiments. The findings were compared with the volumes measured by a flowmeter in the pulmonary artery. The total stroke volume was found to be proportional to the difference between the maximum and mean densitometric volume. A comparison between videodensitometry and other non-invasive methods showed that, in a stable circulatory system, the results of videodensitometry are equally reliable as, or even more reliable than, those of the conventional methods. (orig./MG) [de

  20. Bayesian prediction of future ice sheet volume using local approximation Markov chain Monte Carlo methods

    Science.gov (United States)

    Davis, A. D.; Heimbach, P.; Marzouk, Y.

    2017-12-01

    We develop a Bayesian inverse modeling framework for predicting future ice sheet volume with associated formal uncertainty estimates. Marine ice sheets are drained by fast-flowing ice streams, which we simulate using a flowline model. Flowline models depend on geometric parameters (e.g., basal topography), parameterized physical processes (e.g., calving laws and basal sliding), and climate parameters (e.g., surface mass balance), most of which are unknown or uncertain. Given observations of ice surface velocity and thickness, we define a Bayesian posterior distribution over static parameters, such as basal topography. We also define a parameterized distribution over variable parameters, such as future surface mass balance, which we assume are not informed by the data. Hyperparameters are used to represent climate change scenarios, and sampling their distributions mimics internal variation. For example, a warming climate corresponds to increasing mean surface mass balance but an individual sample may have periods of increasing or decreasing surface mass balance. We characterize the predictive distribution of ice volume by evaluating the flowline model given samples from the posterior distribution and the distribution over variable parameters. Finally, we determine the effect of climate change on future ice sheet volume by investigating how changing the hyperparameters affects the predictive distribution. We use state-of-the-art Bayesian computation to address computational feasibility. Characterizing the posterior distribution (using Markov chain Monte Carlo), sampling the full range of variable parameters and evaluating the predictive model is prohibitively expensive. Furthermore, the required resolution of the inferred basal topography may be very high, which is often challenging for sampling methods. Instead, we leverage regularity in the predictive distribution to build a computationally cheaper surrogate over the low dimensional quantity of interest (future ice

  1. Analysis of the neutron flux in an annular pulsed reactor by using finite volume method

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Mário A.B. da; Narain, Rajendra; Bezerra, Jair de L., E-mail: mabs500@gmail.com, E-mail: narain@ufpe.br, E-mail: jairbezerra@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociências. Departamento de Energia Nuclear

    2017-07-01

    Production of very intense neutron sources is important for basic nuclear physics and for material testing and isotope production. Nuclear reactors have been used as sources of intense neutron fluxes, although the achievement of such levels is limited by the inability to remove fission heat. Periodic pulsed reactors provide very intense fluxes by a rotating modulator near a subcritical core. A concept for the production of very intense neutron fluxes that combines features of periodic pulsed reactors and steady state reactors was proposed by Narain (1997). Such a concept is known as Very Intense Continuous High Flux Pulsed Reactor (VICHFPR) and was analyzed by using diffusion equation with moving boundary conditions and Finite Difference Method with Crank-Nicolson formalism. This research aims to analyze the flux distribution in the Very Intense Continuous Flux High Pulsed Reactor (VICHFPR) by using the Finite Volume Method and compares its results with those obtained by the previous computational method. (author)

  2. Methods of Celestial Mechanics Volume II: Application to Planetary System, Geodynamics and Satellite Geodesy

    CERN Document Server

    Beutler, Gerhard

    2005-01-01

    G. Beutler's Methods of Celestial Mechanics is a coherent textbook for students as well as an excellent reference for practitioners. Volume II is devoted to the applications and to the presentation of the program system CelestialMechanics. Three major areas of applications are covered: (1) Orbital and rotational motion of extended celestial bodies. The properties of the Earth-Moon system are developed from the simplest case (rigid bodies) to more general cases, including the rotation of an elastic Earth, the rotation of an Earth partly covered by oceans and surrounded by an atmosphere, and the rotation of an Earth composed of a liquid core and a rigid shell (Poincaré model). (2) Artificial Earth Satellites. The oblateness perturbation acting on a satellite and the exploitation of its properties in practice is discussed using simulation methods (CelestialMechanics) and (simplified) first order perturbation methods. The perturbations due to the higher-order terms of the Earth's gravitational potential and reso...

  3. Hybrid Multiscale Finite Volume method for multiresolution simulations of flow and reactive transport in porous media

    Science.gov (United States)

    Barajas-Solano, D. A.; Tartakovsky, A. M.

    2017-12-01

    We present a multiresolution method for the numerical simulation of flow and reactive transport in porous, heterogeneous media, based on the hybrid Multiscale Finite Volume (h-MsFV) algorithm. The h-MsFV algorithm allows us to couple high-resolution (fine scale) flow and transport models with lower resolution (coarse) models to locally refine both spatial resolution and transport models. The fine scale problem is decomposed into various "local'' problems solved independently in parallel and coordinated via a "global'' problem. This global problem is then coupled with the coarse model to strictly ensure domain-wide coarse-scale mass conservation. The proposed method provides an alternative to adaptive mesh refinement (AMR), due to its capacity to rapidly refine spatial resolution beyond what's possible with state-of-the-art AMR techniques, and the capability to locally swap transport models. We illustrate our method by applying it to groundwater flow and reactive transport of multiple species.

  4. Analysis of the neutron flux in an annular pulsed reactor by using finite volume method

    International Nuclear Information System (INIS)

    Silva, Mário A.B. da; Narain, Rajendra; Bezerra, Jair de L.

    2017-01-01

    Production of very intense neutron sources is important for basic nuclear physics and for material testing and isotope production. Nuclear reactors have been used as sources of intense neutron fluxes, although the achievement of such levels is limited by the inability to remove fission heat. Periodic pulsed reactors provide very intense fluxes by a rotating modulator near a subcritical core. A concept for the production of very intense neutron fluxes that combines features of periodic pulsed reactors and steady state reactors was proposed by Narain (1997). Such a concept is known as Very Intense Continuous High Flux Pulsed Reactor (VICHFPR) and was analyzed by using diffusion equation with moving boundary conditions and Finite Difference Method with Crank-Nicolson formalism. This research aims to analyze the flux distribution in the Very Intense Continuous Flux High Pulsed Reactor (VICHFPR) by using the Finite Volume Method and compares its results with those obtained by the previous computational method. (author)

  5. The role of foundations: Rockefeller Foundation.

    Science.gov (United States)

    Rockefeller, David

    The consequences of climate change and the impacts of human activity on the environment have made it clearer than ever before that we must evolve our current model of public health to better account for the inextricable link between human health and the natural systems on which it depends-creating a "public health 2.0" that builds on the innovations of the twentieth century to account for a world where humans have bypassed planetary boundaries to achieve well-being. First coined at the Rockefeller Foundation's Centennial gathering in Beijing in 2013, "Planetary Health" will factor in future health and environmental harms over present-day gains, particularly those that disproportionately affect the poor and those in developing nations. To build this new field, foundations must address the challenge of information, increasing support for research to bridge knowledge gaps on the links between economic development, natural systems, and human health.

  6. Scintigraphic method for evaluating reductions in local blood volumes in human extremities

    DEFF Research Database (Denmark)

    Blønd, L; Madsen, Jan Lysgård

    2000-01-01

    were carried out. No significant differences between results obtained by the use of one or two scintigraphic projections were found. The between-subject coefficient of variation was 14% in the lower limb experiment and 11% in the upper limb experiment. The within-subject coefficient of variation was 6......% in the lower limb experiment and 6% in the upper limb experiment. We found a significant relation (r = 0.42, p = 0.018) between the results obtained by the scintigraphic method and the plethysmographic method. In fractions, a mean reduction in blood volume of 0.49+0.14 (2 SD) was found after 1 min of elevation...... of the lower limb and a mean reduction of 0.45+/-0.10 (2 SD) after half a minute of elevation of the upper limb. We conclude that the method is precise and can be used in investigating physiologic and pathophysiologic mechanisms in relation to blood volumes of limbs not subject to research previously....

  7. Method for volume reduction and encapsulation of water-bearing, low-level radioactive wastes

    International Nuclear Information System (INIS)

    1982-01-01

    The invention relates to the processing of water-bearing wastes, especially those containing radioactive materials from nuclear power plants like light-water moderated and cooled reactors. The invention provides a method to reduce the volume of wastes like contaminated coolants and to dispose them safely. According to the invention, azeotropic drying is applied to remove the water. Distilation temperatures are chosen to be lower than the lowest boiling point of the mixture components. In the preferred version, a polymerizing monomer is used to obtain the azeotropic mixture. In doing so, encapsulation is possible by combination with a co-reactive polymer that envelopes the waste material. (G.J.P.)

  8. Method of moments solution of volume integral equations using higher-order hierarchical Legendre basis functions

    DEFF Research Database (Denmark)

    Kim, Oleksiy S.; Jørgensen, Erik; Meincke, Peter

    2004-01-01

    An efficient higher-order method of moments (MoM) solution of volume integral equations is presented. The higher-order MoM solution is based on higher-order hierarchical Legendre basis functions and higher-order geometry modeling. An unstructured mesh composed of 8-node trilinear and/or curved 27...... of magnitude in comparison to existing higher-order hierarchical basis functions. Consequently, an iterative solver can be applied even for high expansion orders. Numerical results demonstrate excellent agreement with the analytical Mie series solution for a dielectric sphere as well as with results obtained...

  9. A finite volume method for density driven flows in porous media

    Directory of Open Access Journals (Sweden)

    Hilhorst Danielle

    2013-01-01

    Full Text Available In this paper, we apply a semi-implicit finite volume method for the numerical simulation of density driven flows in porous media; this amounts to solving a nonlinear convection-diffusion parabolic equation for the concentration coupled with an elliptic equation for the pressure. We compute the solutions for two specific problems: a problem involving a rotating interface between salt and fresh water and the classical but difficult Henry’s problem. All solutions are compared to results obtained by running FEflow, a commercial software package for the simulation of groundwater flow, mass and heat transfer in porous media.

  10. NUMERICAL MODELLING OF CHICKEN-FOOT FOUNDATION

    Directory of Open Access Journals (Sweden)

    Vipman Tandjiria

    1999-01-01

    Full Text Available This paper presents an analysis of the chicken-foot foundation using the finite element method. The foundation is considered as a reinforced concrete slab resting on a number of reinforced concrete pipes filled with and surrounded by in-situ soil. The soil and the pipes were modelled by isoparametric solid elements while the slab was modelled by isoparametric thick-plate elements. The study was intended to illustrate the basic mechanism of the chicken-foot foundation. Three cases have been considered for the parametric studies. The parameters investigated are thickness of slab, length of pipes and spacing between pipes. It is shown that such a foundation improves the behaviour of the raft foundation. It is also found that all the parameters used in the parametric studies influence the behaviour of the chicken-foot foundation.

  11. Simulation of 3D parachute fluid–structure interaction based on nonlinear finite element method and preconditioning finite volume method

    Directory of Open Access Journals (Sweden)

    Fan Yuxin

    2014-12-01

    Full Text Available A fluid–structure interaction method combining a nonlinear finite element algorithm with a preconditioning finite volume method is proposed in this paper to simulate parachute transient dynamics. This method uses a three-dimensional membrane–cable fabric model to represent a parachute system at a highly folded configuration. The large shape change during parachute inflation is computed by the nonlinear Newton–Raphson iteration and the linear system equation is solved by the generalized minimal residual (GMRES method. A membrane wrinkling algorithm is also utilized to evaluate the special uniaxial tension state of membrane elements on the parachute canopy. In order to avoid large time expenses during structural nonlinear iteration, the implicit Hilber–Hughes–Taylor (HHT time integration method is employed. For the fluid dynamic simulations, the Roe and HLLC (Harten–Lax–van Leer contact scheme has been modified and extended to compute flow problems at all speeds. The lower–upper symmetric Gauss–Seidel (LU-SGS approximate factorization is applied to accelerate the numerical convergence speed. Finally, the test model of a highly folded C-9 parachute is simulated at a prescribed speed and the results show similar characteristics compared with experimental results and previous literature.

  12. The ratio of right ventricular volume to left ventricular volume reflects the impact of pulmonary regurgitation independently of the method of pulmonary regurgitation quantification

    International Nuclear Information System (INIS)

    Śpiewak, Mateusz; Małek, Łukasz A.; Petryka, Joanna; Mazurkiewicz, Łukasz; Miłosz, Barbara; Biernacka, Elżbieta K.; Kowalski, Mirosław; Hoffman, Piotr; Demkow, Marcin; Miśko, Jolanta; Rużyłło, Witold

    2012-01-01

    Background: Previous studies have advocated quantifying pulmonary regurgitation (PR) by using PR volume (PRV) instead of commonly used PR fraction (PRF). However, physicians are not familiar with the use of PRV in clinical practice. The ratio of right ventricle (RV) volume to left ventricle volume (RV/LV) may better reflect the impact of PR on the heart than RV end-diastolic volume (RVEDV) alone. We aimed to compare the impact of PRV and PRF on RV size expressed as either the RV/LV ratio or RVEDV (mL/m 2 ). Methods: Consecutive patients with repaired tetralogy of Fallot were included (n = 53). PRV, PRF and ventricular volumes were measured with the use of cardiac magnetic resonance. Results: RVEDV was more closely correlated with PRV when compared with PRF (r = 0.686, p 2.0 [area under the curve (AUC) PRV = 0.770 vs AUC PRF = 0.777, p = 0.86]. Conversely, with the use of the RVEDV-based criterion (>170 mL/m 2 ), PRV proved to be superior over PRF (AUC PRV = 0.770 vs AUC PRF = 0.656, p = 0.0028]. Conclusions: PRV and PRF have similar significance as measures of PR when the RV/LV ratio is used instead of RVEDV. The RV/LV ratio is a universal marker of RV dilatation independent of the method of PR quantification applied (PRF vs PRV)

  13. Volume-monitored chest CT: a simplified method for obtaining motion-free images near full inspiratory and end expiratory lung volumes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Kathryn S. [The Ohio State University College of Medicine, Columbus, OH (United States); Long, Frederick R. [Nationwide Children' s Hospital, The Children' s Radiological Institute, Columbus, OH (United States); Flucke, Robert L. [Nationwide Children' s Hospital, Department of Pulmonary Medicine, Columbus, OH (United States); Castile, Robert G. [The Research Institute at Nationwide Children' s Hospital, Center for Perinatal Research, Columbus, OH (United States)

    2010-10-15

    Lung inflation and respiratory motion during chest CT affect diagnostic accuracy and reproducibility. To describe a simple volume-monitored (VM) method for performing reproducible, motion-free full inspiratory and end expiratory chest CT examinations in children. Fifty-two children with cystic fibrosis (mean age 8.8 {+-} 2.2 years) underwent pulmonary function tests and inspiratory and expiratory VM-CT scans (1.25-mm slices, 80-120 kVp, 16-40 mAs) according to an IRB-approved protocol. The VM-CT technique utilizes instruction from a respiratory therapist, a portable spirometer and real-time documentation of lung volume on a computer. CT image quality was evaluated for achievement of targeted lung-volume levels and for respiratory motion. Children achieved 95% of vital capacity during full inspiratory imaging. For end expiratory scans, 92% were at or below the child's end expiratory level. Two expiratory exams were judged to be at suboptimal volumes. Two inspiratory (4%) and three expiratory (6%) exams showed respiratory motion. Overall, 94% of scans were performed at optimal volumes without respiratory motion. The VM-CT technique is a simple, feasible method in children as young as 4 years to achieve reproducible high-quality full inspiratory and end expiratory lung CT images. (orig.)

  14. Evaluation of left ventricular volume by MRI using modified Simpson's rule method

    International Nuclear Information System (INIS)

    Okamura, Masahiro; Kondo, Takeshi; Anno, Naoko

    1990-01-01

    The conventional contrast left ventriculogrpahy (LVG) has been the gold standard for estimating left ventricular volume (LVV), but it is an invasive technique, and volume overload must be caused by contrast medium. the true left ventricular (LV) long axis may not be obtained by LVG in routine right anterior oblique (RAO) projection. MRI, on the other hand, is noninvasive, does not require contrast medium, and permits to obtain the true LV long axis sections. Thus, MRI seems the ideal technique for estimating LVV. To estimate LVV, we have developed the on-line programs for calculating LVV by single-plane (SMS) or biplane modified Simpson's rule method (BMS), and have applied these programs to the water in the bottle with the elliptic short axis plane, normal volunteer and patients with various heart diseases. In the water phantom, the water volume calculated by the BMS was more accurate than the SMS. In nine normal volunteers, multiple LV short axis sections in each end-systole and end-diastole were obtained by ECG-gated spin echo MRI, LVV as standard was calculated by true Simpson's rule method (TS) on these images. Then both vertical and horizontal LV long axis sections were also obtained by ECG-gated field echo (FE) rephasing cine MRI, LVV was calculated by the BMS or SMS on these images. The BMS or SMS significantly correlated (r=0.974, r=0.927, 0.947) with TS for estimating LVV, respectively. In 20 patients with various heart diseases, both vertical and horizontal LV long axis sections were obtained by FE cine MRI. LVV (r=0.907 and r=0.901) and EF (r=0.822 and r=0.938) calculated by the SMS on the vertical or horizontal LV long axis sections significantly correlated with the conventional RAO-LVG, respectively. In conclusion, the MRI using our on-line programs would be clinically useful for estimating LVV and EF. (author)

  15. SOLA-VOF, 2-D Transient Hydrodynamic Using Fractional Volume of Fluid Method

    International Nuclear Information System (INIS)

    Nichols, B.D.; Hirt, C.W.; Hotchkiss, R.S.

    1991-01-01

    1 - Description of problem or function: SOLA-VOF is a program for the solution of two-dimensional transient fluid flow with free boundaries, based on the concept of a fractional volume of fluid (VOF). Its basic mode of operation is for single fluid calculations having multiple free surfaces. However, SOLA-VOF can also be used for calculations involving two fluids separated by a sharp interface. In either case, the fluids may be treated as incompressible or as having limited compressibility. Surface tension forces with wall adhesion are permitted in both cases. Internal obstacles may be defined by blocking out any desired combination of cells in the mesh, which is composed of rectangular cells of variable size. 2 - Method of solution: The basis of the SOLA-VOF method is the fractional volume of fluid scheme for tracking free boundaries. In this technique, a function F(x,y,t) is defined whose value is unity at any point occupied by fluid and zero elsewhere. When averaged over the cells of a computational mesh, the average value of F in a cell is equal to the fractional volume of the cell occupied by fluid. In particular, a unit value of F corresponds to a cell full of fluid, whereas a zero value indicates that the cell contains no fluid. Cells with F values between zero and one contain a free surface. SOLA-VOF uses an Eulerian mesh of rectangular cells having variable sizes. The fluid equations solved are the finite difference approximations of the Navier-Stokes equations. 3 - Restrictions on the complexity of the problem: The setting of array dimensions is controlled through PARAMETER statements

  16. High order spectral volume and spectral difference methods on unstructured grids

    Science.gov (United States)

    Kannan, Ravishekar

    The spectral volume (SV) and the spectral difference (SD) methods were developed by Wang and Liu and their collaborators for conservation laws on unstructured grids. They were introduced to achieve high-order accuracy in an efficient manner. Recently, these methods were extended to three-dimensional systems and to the Navier Stokes equations. The simplicity and robustness of these methods have made them competitive against other higher order methods such as the discontinuous Galerkin and residual distribution methods. Although explicit TVD Runge-Kutta schemes for the temporal advancement are easy to implement, they suffer from small time step limited by the Courant-Friedrichs-Lewy (CFL) condition. When the polynomial order is high or when the grid is stretched due to complex geometries or boundary layers, the convergence rate of explicit schemes slows down rapidly. Solution strategies to remedy this problem include implicit methods and multigrid methods. A novel implicit lower-upper symmetric Gauss-Seidel (LU-SGS) relaxation method is employed as an iterative smoother. It is compared to the explicit TVD Runge-Kutta smoothers. For some p-multigrid calculations, combining implicit and explicit smoothers for different p-levels is also studied. The multigrid method considered is nonlinear and uses Full Approximation Scheme (FAS). An overall speed-up factor of up to 150 is obtained using a three-level p-multigrid LU-SGS approach in comparison with the single level explicit method for the Euler equations for the 3rd order SD method. A study of viscous flux formulations was carried out for the SV method. Three formulations were used to discretize the viscous fluxes: local discontinuous Galerkin (LDG), a penalty method and the 2nd method of Bassi and Rebay. Fourier analysis revealed some interesting advantages for the penalty method. These were implemented in the Navier Stokes solver. An implicit and p-multigrid method was also implemented for the above. An overall speed

  17. Teaching Thermal Hydraulics and Numerical Methods: An Introductory Control Volume Primer

    International Nuclear Information System (INIS)

    D. S. Lucas

    2004-01-01

    A graduate level course for Thermal Hydraulics (T/H) was taught through Idaho State University in the spring of 2004. A numerical approach was taken for the content of this course since the students were employed at the Idaho National Laboratory and had been users of T/H codes. The majority of the students had expressed an interest in learning about the Courant Limit, mass error, semi-implicit and implicit numerical integration schemes in the context of a computer code. Since no introductory text was found the author developed notes taught from his own research and courses taught for Westinghouse on the subject. The course started with a primer on control volume methods and the construction of a Homogeneous Equilibrium Model (HEM) (T/H) code. The primer was valuable for giving the students the basics behind such codes and their evolution to more complex codes for Thermal Hydraulics and Computational Fluid Dynamics (CFD). The course covered additional material including the Finite Element Method and non-equilibrium (T/H). The control volume primer and the construction of a three-equation (mass, momentum and energy) HEM code are the subject of this paper . The Fortran version of the code covered in this paper is elementary compared to its descendants. The steam tables used are less accurate than the available commercial version written in C Coupled to a Graphical User Interface (GUI). The Fortran version and input files can be downloaded at www.microfusionlab.com

  18. Modelling of Evaporator in Waste Heat Recovery System using Finite Volume Method and Fuzzy Technique

    Directory of Open Access Journals (Sweden)

    Jahedul Islam Chowdhury

    2015-12-01

    Full Text Available The evaporator is an important component in the Organic Rankine Cycle (ORC-based Waste Heat Recovery (WHR system since the effective heat transfer of this device reflects on the efficiency of the system. When the WHR system operates under supercritical conditions, the heat transfer mechanism in the evaporator is unpredictable due to the change of thermo-physical properties of the fluid with temperature. Although the conventional finite volume model can successfully capture those changes in the evaporator of the WHR process, the computation time for this method is high. To reduce the computation time, this paper develops a new fuzzy based evaporator model and compares its performance with the finite volume method. The results show that the fuzzy technique can be applied to predict the output of the supercritical evaporator in the waste heat recovery system and can significantly reduce the required computation time. The proposed model, therefore, has the potential to be used in real time control applications.

  19. Dynamics study of free volume properties of SMA/SMMA blends by PAL method

    International Nuclear Information System (INIS)

    Jiang, Z.Y.; Jiang, X.Q.; Huang, Y.J.; Lin, J.; Li, S.M.; Li, S.Z.; Hsia, Y.F.

    2006-01-01

    Miscibility of poly(styrene-co-maleic anhydride) (containing 7 wt% maleic anhydride)/poly(styrene-co-methyl methacrylate) (containing 40 wt% styrene) blends were previously studied. It was obtained that SMA70 (containing 70 wt% of SMA in SMA/SMMA blends) is miscible in molecular level but SMA20 is not. In this paper, the two blends selected were used to investigate the temperature dependence of free volume parameters. It showed there are different deviations of free volume parameters in SMA20 and SMA70, and it was interesting that temperature dependence of ortho-positronium lifetime τ 3 of the SMA20 mixture exhibits two breaks in the range temperature from 90 deg. C to 120 deg. C, which revealed that the mixture has two glass transition ranges. Also, ortho-positronium lifetime τ 3 of the SMA20 mixture is nearly constant in the temperature range from 130 deg. C to 160 deg. C. These indicated that SMA20 blend is phase-separated in room temperature and become miscible above 130 deg. C, which may be due to steric hindrance effect of phenyl rings of SMMA and SMA. From the deviation of o-Ps lifetimes of SMA70, the single glass transition temperature of SMA70 blend was shown. Combining the previous study, it was further concluded that PAL method seems to be a powerful method to detect in situ phase behavior of immiscible polymer blends and glass transition of miscible polymer blends

  20. Measurement of disintegration rates of 60Co volume sources by the sum-peak method

    International Nuclear Information System (INIS)

    Kawano, Takao; Ebihara, Hiroshi

    1991-01-01

    The sum-peak method has been applied to the determination of the disintegration rates of 60 Co volume sources (1.05 x 10 4 Bq, 1.05 x 10 3 Bq and 1.05 x 10 2 Bq, in 100-ml polyethylene bottles) by using a NaI(Tl) detector of a diameter of 50 mm and a height of 50 mm. The experimental results showed that decreasing the disintegration rates resulted in enlarged underestimation in comparison with the true disintegration rates. It was presumed that the underestimations of the disintegration rates determined by the sum-peak method resulted from the overestimations of the areas under the sum peaks caused by the overlap of the area under the Compton scattering of the γ-ray (2614 keV) emitted from a naturally occurring radionuclide 208 Tl under the sum peaks. (author)

  1. Gas permeation measurement under defined humidity via constant volume/variable pressure method

    KAUST Repository

    Jan Roman, Pauls

    2012-02-01

    Many industrial gas separations in which membrane processes are feasible entail high water vapour contents, as in CO 2-separation from flue gas in carbon capture and storage (CCS), or in biogas/natural gas processing. Studying the effect of water vapour on gas permeability through polymeric membranes is essential for materials design and optimization of these membrane applications. In particular, for amine-based CO 2 selective facilitated transport membranes, water vapour is necessary for carrier-complex formation (Matsuyama et al., 1996; Deng and Hägg, 2010; Liu et al., 2008; Shishatskiy et al., 2010) [1-4]. But also conventional polymeric membrane materials can vary their permeation behaviour due to water-induced swelling (Potreck, 2009) [5]. Here we describe a simple approach to gas permeability measurement in the presence of water vapour, in the form of a modified constant volume/variable pressure method (pressure increase method). © 2011 Elsevier B.V.

  2. Test Functions for Three-Dimensional Control-Volume Mixed Finite-Element Methods on Irregular Grids

    National Research Council Canada - National Science Library

    Naff, R. L; Russell, T. F; Wilson, J. D

    2000-01-01

    .... For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error...

  3. New digital measurement methods for left ventricular volume using real-time three-dimensional echocardiography: comparison with electromagnetic flow method and magnetic resonance imaging

    Science.gov (United States)

    Qin, J. J.; Jones, M.; Shiota, T.; Greenberg, N. L.; Firstenberg, M. S.; Tsujino, H.; Zetts, A. D.; Sun, J. P.; Cardon, L. A.; Odabashian, J. A.; hide

    2000-01-01

    AIM: The aim of this study was to investigate the feasibility and accuracy of using symmetrically rotated apical long axis planes for the determination of left ventricular (LV) volumes with real-time three-dimensional echocardiography (3DE). METHODS AND RESULTS: Real-time 3DE was performed in six sheep during 24 haemodynamic conditions with electromagnetic flow measurements (EM), and in 29 patients with magnetic resonance imaging measurements (MRI). LV volumes were calculated by Simpson's rule with five 3DE methods (i.e. apical biplane, four-plane, six-plane, nine-plane (in which the angle between each long axis plane was 90 degrees, 45 degrees, 30 degrees or 20 degrees, respectively) and standard short axis views (SAX)). Real-time 3DE correlated well with EM for LV stroke volumes in animals (r=0.68-0.95) and with MRI for absolute volumes in patients (r-values=0.93-0.98). However, agreement between MRI and apical nine-plane, six-plane, and SAX methods in patients was better than those with apical four-plane and bi-plane methods (mean difference = -15, -18, -13, vs. -31 and -48 ml for end-diastolic volume, respectively, Pmethods of real-time 3DE correlated well with reference standards for calculating LV volumes. Balancing accuracy and required time for these LV volume measurements, the apical six-plane method is recommended for clinical use.

  4. Pulmonary Fibrosis Foundation

    Science.gov (United States)

    ... submissions. MORE We Imagine a World Without Pulmonary Fibrosis The Pulmonary Fibrosis Foundation mobilizes people and resources to provide ... its battle against the deadly lung disease, pulmonary fibrosis (PF). PULMONARY FIBROSIS WALK SURPASSES PARTICIPATION AND FUNDRAISING GOALS Nearly ...

  5. Women's Heart Foundation

    Science.gov (United States)

    ... News Email: Click for e-News archive The Women's Heart Foundation is a 501c3 dedicated to prevention, ... Care Initiative® to achieve excellence of care of women. Executive nurses, civic leaders, women survivors and sponsors ...

  6. Pediatric Brain Tumor Foundation

    Science.gov (United States)

    ... navigate their brain tumor diagnosis. WATCH AND SHARE Brain tumors and their treatment can be deadly so ... Pediatric Central Nervous System Cancers Read more >> Pediatric Brain Tumor Foundation 302 Ridgefield Court, Asheville, NC 28806 ...

  7. Children's Brain Tumor Foundation

    Science.gov (United States)

    ... 2 Family Donate Volunteer Justin's Hope Fund Children’s Brain Tumor Foundation, A non-profit organization, was founded ... and the long term outlook for children with brain and spinal cord tumors through research, support, education, ...

  8. The foundations of statistics

    CERN Document Server

    Savage, Leonard J

    1972-01-01

    Classic analysis of the foundations of statistics and development of personal probability, one of the greatest controversies in modern statistical thought. Revised edition. Calculus, probability, statistics, and Boolean algebra are recommended.

  9. National Psoriasis Foundation

    Science.gov (United States)

    ... 723-9166 | Submit a Question | Learn More National Psoriasis Foundation provides you with the help you need to best manage your psoriasis or psoriatic arthritis, while promoting research to find ...

  10. Hepatitis B Foundation

    Science.gov (United States)

    ... worldwide 2 Billion People have been infected with Hepatitis B Worldwide The Hepatitis B Foundation is working ... of people living with hepatitis B. Learn About Hepatitis B in 11 Other Languages . Resource Video See ...

  11. Multiple Myeloma Research Foundation

    Science.gov (United States)

    ... MMRF Founder Kathy Giusti named 1 of 100 Visionaries of our time by the Einstein Foundation Learn More September 8, 2017 Tom Brokaw gives inspiring speech at MMRF Leadership Circle Summit on how his life was changed, ...

  12. American Lyme Disease Foundation

    Science.gov (United States)

    ... Infectious Diseases, 35: 451-464, 2002) What is Lyme Disease? Lyme disease (LD) is an infection caused by ... mission with your own tax-deductible contribution. American Lyme Disease Foundation, Inc. PO Box 466 Lyme, CT 06371 ...

  13. American Vitiligo Research Foundation

    Science.gov (United States)

    ... Place Vitiligo Voices Contact Welcome to The American Vitiligo Foundation Home Page Top Isabella T., California An ... 20.00 USD 20 for - 35.00 USD Vitiligo Doesn't Scare Me by Kim Kirkland Kim ...

  14. Moebius Syndrome Foundation

    Science.gov (United States)

    ... craniofacial/neurological disorder. Individuals with Moebius syndrome cannot smile or frown, and do not have lateral eye ... the organization to ensure that they are in line with the mission of the Moebius Syndrome Foundation. ...

  15. National Headache Foundation

    Science.gov (United States)

    ... Headache Topic Sheets (Spanish) Headache FAQ NHF Webinars Education Modules MigrainePro™ Children’s Headache Disorders New Perspectives on Caffeine and Headache War Veterans Health Resource Initiative National Headache Foundation Brochures ...

  16. Intracranial Hypertension Research Foundation

    Science.gov (United States)

    ... PARTNERSHIPS Meet our Fundraising Partners Tweet Welcome Intracranial hypertension (IH) is the general term for the neurological ... high. (Old names for IH include Benign Intracranial Hypertension and Pseudotumor Cerebri). The Intracranial Hypertension Research Foundation ...

  17. Oral Cancer Foundation

    Science.gov (United States)

    ... Get involved Understanding Dental Research People Resources About Understanding Events Get involved Dental Research Resources Contact Sitemap The Oral Cancer Foundation admin 2017-11-12T16:49:25+ ...

  18. Foundations of laser spectroscopy

    CERN Document Server

    Stenholm, Stig

    2005-01-01

    A simple presentation of the theoretical foundations of steady-state laser spectroscopy, this text helps students to apply theory to calculations with a systematic series of examples and exercises. 1984 edition.

  19. International OCD Foundation

    Science.gov (United States)

    ... and productive lives. Join Donate Volunteer Events International OCD Foundation Research. Resources. Respect. About OCD About IOCDF ... Donate Here Why Should You Attend the Annual OCD Conference? Watch the Video Find Help Search the ...

  20. Foundational aspects of security

    DEFF Research Database (Denmark)

    Chatzikokolakis, Konstantinos; Mödersheim, Sebastian Alexander; Palamidessi, Catuscia

    2014-01-01

    This Special Issue of the Journal of Computer Security focuses on foundational aspects of security, which in recent years have helped change much of the way we think about and approach system security.......This Special Issue of the Journal of Computer Security focuses on foundational aspects of security, which in recent years have helped change much of the way we think about and approach system security....

  1. Foundations of Neuromorphic Computing

    Science.gov (United States)

    2013-05-01

    paradigms: few sensors/complex computations and many sensors/simple computation. Challenges with Nano-enabled Neuromorphic Chips A wide variety of...FOUNDATIONS OF NEUROMORPHIC COMPUTING MAY 2013 FINAL TECHNICAL REPORT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION...2009 – SEP 2012 4. TITLE AND SUBTITLE FOUNDATIONS OF NEUROMORPHIC COMPUTING 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT NUMBER N/A 5c. PROGRAM

  2. Research on volume metrology method of large vertical energy storage tank based on internal electro-optical distance-ranging method

    Science.gov (United States)

    Hao, Huadong; Shi, Haolei; Yi, Pengju; Liu, Ying; Li, Cunjun; Li, Shuguang

    2018-01-01

    A Volume Metrology method based on Internal Electro-optical Distance-ranging method is established for large vertical energy storage tank. After analyzing the vertical tank volume calculation mathematical model, the key processing algorithms, such as gross error elimination, filtering, streamline, and radius calculation are studied for the point cloud data. The corresponding volume values are automatically calculated in the different liquids by calculating the cross-sectional area along the horizontal direction and integrating from vertical direction. To design the comparison system, a vertical tank which the nominal capacity is 20,000 m3 is selected as the research object, and there are shown that the method has good repeatability and reproducibility. Through using the conventional capacity measurement method as reference, the relative deviation of calculated volume is less than 0.1%, meeting the measurement requirements. And the feasibility and effectiveness are demonstrated.

  3. Foundation heat transfer analysis for buildings with thermal piles

    International Nuclear Information System (INIS)

    Almanza Huerta, Luis Enrique; Krarti, Moncef

    2015-01-01

    Highlights: • A numerical transient thermal model for thermo-active foundations is developed. • Thermal interactions between thermal piles and building foundations are evaluated. • A simplified analysis method of thermal interactions between thermal piles and building foundations is developed. - Abstract: Thermal piles or thermo-active foundations utilize heat exchangers embedded within foundation footings to heat and/or cool buildings. In this paper, the impact of thermal piles on building foundation heat transfer is investigated. In particular, a simplified analysis method is developed to estimate the annual ground-coupled foundation heat transfer when buildings are equipped with thermal piles. First, a numerical analysis of the thermal performance of thermo-active building foundations is developed and used to assess the interactions between thermal piles and slab-on-grade building foundations. The impact of various design parameters and operating conditions is evaluated including foundation pile depth, building slab width, foundation insulation configuration, and soil thermal properties. Based on the results of a series of parametric analyses, a simplified analysis method is presented to assess the impact of the thermal piles on the annual heat fluxes toward or from the building foundations. A comparative evaluation of the predictions of the simplified analysis method and those obtained from the detailed numerical analysis indicated good agreement with prediction accuracy lower than 5%. Moreover, it is found that thermal piles can affect annual building foundation heat loss/gain by up to 30% depending on foundation size and insulation level

  4. Computational methods and modeling. 1. Sampling a Position Uniformly in a Trilinear Hexahedral Volume

    International Nuclear Information System (INIS)

    Urbatsch, Todd J.; Evans, Thomas M.; Hughes, H. Grady

    2001-01-01

    Monte Carlo particle transport plays an important role in some multi-physics simulations. These simulations, which may additionally involve deterministic calculations, typically use a hexahedral or tetrahedral mesh. Trilinear hexahedrons are attractive for physics calculations because faces between cells are uniquely defined, distance-to-boundary calculations are deterministic, and hexahedral meshes tend to require fewer cells than tetrahedral meshes. We discuss one aspect of Monte Carlo transport: sampling a position in a tri-linear hexahedron, which is made up of eight control points, or nodes, and six bilinear faces, where each face is defined by four non-coplanar nodes in three-dimensional Cartesian space. We derive, code, and verify the exact sampling method and propose an approximation to it. Our proposed approximate method uses about one-third the memory and can be twice as fast as the exact sampling method, but we find that its inaccuracy limits its use to well-behaved hexahedrons. Daunted by the expense of the exact method, we propose an alternate approximate sampling method. First, calculate beforehand an approximate volume for each corner of the hexahedron by taking one-eighth of the volume of an imaginary parallelepiped defined by the corner node and the three nodes to which it is directly connected. For the sampling, assume separability in the parameters, and sample each parameter, in turn, from a linear pdf defined by the sum of the four corner volumes at each limit (-1 and 1) of the parameter. This method ignores the quadratic portion of the pdf, but it requires less storage, has simpler sampling, and needs no extra, on-the-fly calculations. We simplify verification by designing tests that consist of one or more cells that entirely fill a unit cube. Uniformly sampling complicated cells that fill a unit cube will result in uniformly sampling the unit cube. Unit cubes are easily analyzed. The first problem has four wedges (or tents, or A frames) whose

  5. Comparison of left and right ventricular volume measurement using the Simpson's method and the area length method

    International Nuclear Information System (INIS)

    Hergan, Klaus; Schuster, Antonius; Fruehwald, Julia; Mair, Michael; Burger, Ralph; Toepker, Michael

    2008-01-01

    Purpose: To compare ventricular volume measurement using a volumetric approach in the three standard cardiac planes and ventricular volume estimation by a geometrical model, the Area-Length method (ALM). Materials and methods: Fifty-six healthy volunteers were examined (27 males, 29 females) on a 1.5 T MR-unit with ECG-triggered steady state free precision (SSFP) Cine-MR sequences and parallel image acquisition. Multiple slices in standardized planes including the short-axis view (sa), 4-chamber view (4ch), left and right 2-chamber views (2ch) were used to cover the whole heart. End-systolic and end-diastolic ventricular volumes (EDV, ESV), stroke volume (SV), and ejection fraction (EF) were calculated with Simpson's rule in all planes and with ALM in the 2ch and 4ch planes. Global function parameters measured in the sa plane were compared with those obtained in the other imaging planes. Results: A very good correlation is observed when comparing functional parameters calculated with Simpson's rule in all imaging planes: for instance, the mean EDV/ESV of the left and right ventricle of the female population group measured in sa, 4ch, and 2ch: left ventricle EDV/ESV 114.3/44.4, 120.9/46.5, and 117.7/45.3 ml; right ventricle EDV/ESV 106.6/46.0, 101.2/41.1, and 103.5/43.0 ml. Functional parameters of the left ventricle calculated with ALM in 2ch and 4ch correlate to parameters obtained in sa with Simpson's rule in the range of 5-10%: for instance, the EDV/ESV of the left ventricle of the male population group measured in the sa, 4ch, and 2ch: 160.3/63.5, 163.1/59.0, and 167.0/65.7 ml. Functional parameters of the right ventricle measured with ALM in 4ch are 40-50% lower and calculated in 2ch almost double as high as compared with the parameters obtained in sa with Simpson's rule: for instance, male right ventricular EDV/ESV measured in sa, 4ch, and 2ch: 153.4/68.1, 97.5/34.5, and 280.2/123.2 ml. The EF correlates for all imaging planes measured with the Simpson's rule

  6. Optimization of the Water Volume in the Buckets of Pico Hydro Overshot Waterwheel by Analytical Method

    Science.gov (United States)

    Budiarso; Adanta, Dendy; Warjito; Siswantara, A. I.; Saputra, Pradhana; Dianofitra, Reza

    2018-03-01

    Rapid economic and population growth in Indonesia lead to increased energy consumption, including electricity needs. Pico hydro is considered as the right solution because the cost of investment and operational cost are fairly low. Additionally, Indonesia has many remote areas with high hydro-energy potential. The overshot waterwheel is one of technology that is suitable to be applied in remote areas due to ease of operation and maintenance. This study attempts to optimize bucket dimensions with the available conditions. In addition, the optimization also has a good impact on the amount of generated power because all available energy is utilized maximally. Analytical method is used to evaluate the volume of water contained in bucket overshot waterwheel. In general, there are two stages performed. First, calculation of the volume of water contained in each active bucket is done. If the amount total of water contained is less than the available discharge in active bucket, recalculation at the width of the wheel is done. Second, calculation of the torque of each active bucket is done to determine the power output. As the result, the mechanical power generated from the waterwheel is 305 Watts with the efficiency value of 28%.

  7. SU-E-J-35: Using CBCT as the Alternative Method of Assessing ITV Volume

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Y; Turian, J; Templeton, A; Redler, G; Chu, J [Rush University Medical Center, Chicago, IL (United States)

    2015-06-15

    Purpose To study the accuracy of Internal Target Volumes (ITVs) created on cone beam CT (CBCT) by comparing the visible target volume on CBCT to volumes (GTV, ITV, and PTV) outlined on free breathing (FB) CT and 4DCT. Methods A Quasar Cylindrical Motion Phantom with a 3cm diameter ball (14.14 cc) embedded within a cork insert was set up to simulate respiratory motion with a period of 4 seconds and amplitude of 2cm superioinferiorly and 1cm anterioposteriorly. FBCT and 4DCT images were acquired. A PTV-4D was created on the 4DCT by applying a uniform margin of 5mm to the ITV-CT. PTV-FB was created by applying a margin of the motion range plus 5mm, i.e. total of 1.5cm laterally and 2.5cm superioinferiorly to the GTV outlined on the FBCT. A dynamic conformal arc was planned to treat the PTV-FB with 1mm margin. A CBCT was acquired before the treatment, on which the target was delineated. During the treatment, the position of the target was monitored using the EPID in cine mode. Results ITV-CBCT and ITV-CT were measured to be 56.6 and 62.7cc, respectively, with a Dice Coefficient (DC) of 0.94 and disagreement in center of mass (COM) of 0.59 mm. On the other hand, GTV-FB was 11.47cc, 19% less than the known volume of the ball. PTV-FB and PTV-4D were 149 and 116 cc, with a DC of 0.71. Part of the ITV-CT was not enclosed by the PTV-FB despite the large margin. The cine EPID images have confirmed geometrical misses of the target. Similar under-coverage was observed in one clinical case and captured by the CBCT, where the implanted fiducials moved outside PTV-FB. Conclusion ITV-CBCT is in good agreement with ITV-CT. When 4DCT was not available, CBCT can be an effective alternative in determining and verifying the PTV margin.

  8. A moving control volume method for smooth computation of hydrodynamic forces and torques on immersed bodies

    Science.gov (United States)

    Nangia, Nishant; Patankar, Neelesh A.; Bhalla, Amneet P. S.

    2017-11-01

    Fictitious domain methods for simulating fluid-structure interaction (FSI) have been gaining popularity in the past few decades because of their robustness in handling arbitrarily moving bodies. Often the transient net hydrodynamic forces and torques on the body are desired quantities for these types of simulations. In past studies using immersed boundary (IB) methods, force measurements are contaminated with spurious oscillations due to evaluation of possibly discontinuous spatial velocity of pressure gradients within or on the surface of the body. Based on an application of the Reynolds transport theorem, we present a moving control volume (CV) approach to computing the net forces and torques on a moving body immersed in a fluid. The approach is shown to be accurate for a wide array of FSI problems, including flow past stationary and moving objects, Stokes flow, and high Reynolds number free-swimming. The approach only requires far-field (smooth) velocity and pressure information, thereby suppressing spurious force oscillations and eliminating the need for any filtering. The proposed moving CV method is not limited to a specific IB method and is straightforward to implement within an existing parallel FSI simulation software. This work is supported by NSF (Award Numbers SI2-SSI-1450374, SI2-SSI-1450327, and DGE-1324585), the US Department of Energy, Office of Science, ASCR (Award Number DE-AC02-05CH11231), and NIH (Award Number HL117163).

  9. Stress strain modelling of casting processes in the framework of the control volume method

    DEFF Research Database (Denmark)

    Hattel, Jesper; Andersen, Søren; Thorborg, Jesper

    1998-01-01

    Realistic computer simulations of casting processes call for the solution of both thermal, fluid-flow and stress/strain related problems. The multitude of the influencing parameters, and their non-linear, transient and temperature dependent nature, make the calculations complex. Therefore the nee......, the present model is based on the mainly decoupled representation of the thermal, mechanical and microstructural processes. Examples of industrial applications, such as predicting residual deformations in castings and stress levels in die casting dies, are presented...... for fast, flexible, multidimensional numerical methods is obvious. The basis of the deformation and stress/strain calculation is a transient heat transfer analysis including solidification. This paper presents an approach where the stress/strain and the heat transfer analysis uses the same computational...... domain, which is highly convenient. The basis of the method is the control volume finite difference approach on structured meshes. The basic assumptions of the method are shortly reviewed and discussed. As for other methods which aim at application oriented analysis of casting deformations and stresses...

  10. A critical analysis of some popular methods for the discretisation of the gradient operator in finite volume methods

    Science.gov (United States)

    Syrakos, Alexandros; Varchanis, Stylianos; Dimakopoulos, Yannis; Goulas, Apostolos; Tsamopoulos, John

    2017-12-01

    Finite volume methods (FVMs) constitute a popular class of methods for the numerical simulation of fluid flows. Among the various components of these methods, the discretisation of the gradient operator has received less attention despite its fundamental importance with regards to the accuracy of the FVM. The most popular gradient schemes are the divergence theorem (DT) (or Green-Gauss) scheme and the least-squares (LS) scheme. Both are widely believed to be second-order accurate, but the present study shows that in fact the common variant of the DT gradient is second-order accurate only on structured meshes whereas it is zeroth-order accurate on general unstructured meshes, and the LS gradient is second-order and first-order accurate, respectively. This is explained through a theoretical analysis and is confirmed by numerical tests. The schemes are then used within a FVM to solve a simple diffusion equation on unstructured grids generated by several methods; the results reveal that the zeroth-order accuracy of the DT gradient is inherited by the FVM as a whole, and the discretisation error does not decrease with grid refinement. On the other hand, use of the LS gradient leads to second-order accurate results, as does the use of alternative, consistent, DT gradient schemes, including a new iterative scheme that makes the common DT gradient consistent at almost no extra cost. The numerical tests are performed using both an in-house code and the popular public domain partial differential equation solver OpenFOAM.

  11. Solving transient conduction and radiation heat transfer problems using the lattice Boltzmann method and the finite volume method

    International Nuclear Information System (INIS)

    Mishra, Subhash C.; Roy, Hillol K.

    2007-01-01

    The lattice Boltzmann method (LBM) was used to solve the energy equation of a transient conduction-radiation heat transfer problem. The finite volume method (FVM) was used to compute the radiative information. To study the compatibility of the LBM for the energy equation and the FVM for the radiative transfer equation, transient conduction and radiation heat transfer problems in 1-D planar and 2-D rectangular geometries were considered. In order to establish the suitability of the LBM, the energy equations of the two problems were also solved using the FVM of the computational fluid dynamics. The FVM used in the radiative heat transfer was employed to compute the radiative information required for the solution of the energy equation using the LBM or the FVM (of the CFD). To study the compatibility and suitability of the LBM for the solution of energy equation and the FVM for the radiative information, results were analyzed for the effects of various parameters such as the scattering albedo, the conduction-radiation parameter and the boundary emissivity. The results of the LBM-FVM combination were found to be in excellent agreement with the FVM-FVM combination. The number of iterations and CPU times in both the combinations were found comparable

  12. The finite volume element (FVE) and multigrid method for the incompressible Navier-Stokes equations

    International Nuclear Information System (INIS)

    Gu Lizhen; Bao Weizhu

    1992-01-01

    The authors apply FVE method to discrete INS equations with the original variable, in which the bilinear square finite element and the square finite volume are chosen. The discrete schemes of INS equations are presented. The FMV multigrid algorithm is applied to solve that discrete system, where DGS iteration is used as smoother, DGS distributive mode for the INS discrete system is also presented. The sample problems for the square cavity flow with Reynolds number Re≤100 are successfully calculated. The numerical solutions show that the results with 1 FMV is satisfactory and when Re is not large, The FVE discrete scheme of the conservative INS equations and that of non-conservative INS equations with linearization both can provide almost same accuracy

  13. A solution of two-dimensional magnetohydrodynamic flow using the finite volume method

    Directory of Open Access Journals (Sweden)

    Naceur Sonia

    2014-01-01

    Full Text Available This paper presents the two dimensional numerical modeling of the coupling electromagnetic-hydrodynamic phenomena in a conduction MHD pump using the Finite volume Method. Magnetohydrodynamic problems are, thus, interdisciplinary and coupled, since the effect of the velocity field appears in the magnetic transport equations, and the interaction between the electric current and the magnetic field appears in the momentum transport equations. The resolution of the Maxwell's and Navier Stokes equations is obtained by introducing the magnetic vector potential A, the vorticity z and the stream function y. The flux density, the electromagnetic force, and the velocity are graphically presented. Also, the simulation results agree with those obtained by Ansys Workbench Fluent software.

  14. Application of volume of fluid method for simulation of a droplet impacting a fiber

    Directory of Open Access Journals (Sweden)

    M. Khalili

    2016-06-01

    Full Text Available In the present work, impact of a Newtonian drop on horizontal thin fibers with circular cross section is simulated in 2D views. The numerical simulations of the phenomena are carried out using volume of fluid (VOF method for tracking the free surface motion. Impacting of a Newtonian droplet on a circular thin fiber (350μm radius investigated numerically. The main focus of this simulation is to acquire threshold radius and velocity of a drop which is entirely captured by the fiber. The model agrees well with the experiments and demonstrates the threshold radius decreased generally with the increase of impact velocity. In other words, for velocity larger than threshold velocity of capture perhaps only a small portion of fluid is stuck on the solid and the rest of the drop is ejected for impact velocity smaller than critical velocity the drop is totally captured. This threshold velocity has been determined when the impact is centered.

  15. Methods development for assessing air pollution control benefits. Volume V, executive summary

    International Nuclear Information System (INIS)

    Brookshire, D.S.; Crocker, T.D.; d'Arge, R.C.; Ben-David, S.; Kneese, A.V.; Schulze, W.D.

    1979-02-01

    The studies summarized by this volume represent original efforts to construct both a conceptually consistent and empirically verifiable set of methods for assessing environmental quality improvement benefits. While the state-of-the-art does not at present make it possible to provide highly accurate estimates of the benefits of reduced human or plant exposure to air pollutants, these studies nevertheless provide a set of fundamental benchmarks on which further efforts might be built. There are: many benefits traditionally viewed as intangible and therefore non-measurable can, in fact, be measured and be made comparable to economic values as expressed in markets; aesthetic and morbidity effects may dominate the measure of benefits as opposed to previous emphases on mortality health effects; and the likely economic benefits of air quality improvements are perhaps as much as an order of magnitude greater than previous studies had hypothesized

  16. Development of a high-order finite volume method with multiblock partition techniques

    Directory of Open Access Journals (Sweden)

    E. M. Lemos

    2012-03-01

    Full Text Available This work deals with a new numerical methodology to solve the Navier-Stokes equations based on a finite volume method applied to structured meshes with co-located grids. High-order schemes used to approximate advective, diffusive and non-linear terms, connected with multiblock partition techniques, are the main contributions of this paper. Combination of these two techniques resulted in a computer code that involves high accuracy due the high-order schemes and great flexibility to generate locally refined meshes based on the multiblock approach. This computer code has been able to obtain results with higher or equal accuracy in comparison with results obtained using classical procedures, with considerably less computational effort.

  17. FINITE VOLUME METHOD FOR SOLVING THREE-DIMENSIONAL ELECTRIC FIELD DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Paţiuc V.I.

    2011-04-01

    Full Text Available The paper examines a new approach to finite volume method which is used to calculate the electric field spatially homogeneous three-dimensional environment. It is formulated the problem Dirihle with building of the computational grid on base of space partition, which is known as Delone triangulation with the use of Voronoi cells. It is proposed numerical algorithm for calculating the potential and electric field strength in the space formed by a cylinder placed in the air. It is developed algorithm and software which were for the case, when the potential on the inner surface of the cylinder has been assigned and on the outer surface and the bottom of cylinder it was assigned zero potential. There are presented results of calculations of distribution in the potential space and electric field strength.

  18. Measurement of cardiac ventricular volumes using multidetector row computed tomography: comparison of two- and three-dimensional methods

    International Nuclear Information System (INIS)

    Montaudon, M.; Laffon, E.; Berger, P.; Corneloup, O.; Latrabe, V.; Laurent, F.

    2006-01-01

    This study compared a three-dimensional volumetric threshold-based method to a two-dimensional Simpson's rule based short-axis multiplanar method for measuring right (RV) and left ventricular (LV) volumes, stroke volumes, and ejection fraction using electrocardiography-gated multidetector computed tomography (MDCT) data sets. End-diastolic volume (EDV) and end-systolic volume (ESV) of RV and LV were measured independently and blindly by two observers from contrast-enhanced MDCT images using commercial software in 18 patients. For RV and LV the three-dimensionally calculated EDV and ESV values were smaller than those provided by two-dimensional short axis (10%, 5%, 15% and 26% differences respectively). Agreement between the two methods was found for LV (EDV/ESV: r=0.974/0.910, ICC=0.905/0.890) but not for RV (r=0.882/0.930, ICC=0.663/0.544). Measurement errors were significant only for EDV of LV using the two-dimensional method. Similar reproducibility was found for LV measurements, but the three-dimensional method provided greater reproducibility for RV measurements than the two-dimensional. The threshold value supported three-dimensional method provides reproducible cardiac ventricular volume measurements, comparable to those obtained using the short-axis Simpson based method. (orig.)

  19. Factors affecting volume calculation with single photon emission tomography (SPECT) method

    International Nuclear Information System (INIS)

    Liu, T.H.; Lee, K.H.; Chen, D.C.P.; Ballard, S.; Siegel, M.E.

    1985-01-01

    Several factors may influence the calculation of absolute volumes (VL) from SPECT images. The effect of these factors must be established to optimize the technique. The authors investigated the following on the VL calculations: % of background (BG) subtraction, reconstruction filters, sample activity, angular sampling and edge detection methods. Transaxial images of a liver-trunk phantom filled with Tc-99m from 1 to 3 μCi/cc were obtained in 64x64 matrix with a Siemens Rota Camera and MDS computer. Different reconstruction filters including Hanning 20,32, 64 and Butterworth 20, 32 were used. Angular samplings were performed in 3 and 6 degree increments. ROI's were drawn manually and with an automatic edge detection program around the image after BG subtraction. VL's were calculated by multiplying the number of pixels within the ROI by the slice thickness and the x- and y- calibrations of each pixel. One or 2 pixel per slice thickness was applied in the calculation. An inverse correlation was found between the calculated VL and the % of BG subtraction (r=0.99 for 1,2,3 μCi/cc activity). Based on the authors' linear regression analysis, the correct liver VL was measured with about 53% BG subtraction. The reconstruction filters, slice thickness and angular sampling had only minor effects on the calculated phantom volumes. Detection of the ROI automatically by the computer was not as accurate as the manual method. The authors conclude that the % of BG subtraction appears to be the most important factor affecting the VL calculation. With good quality control and appropriate reconstruction factors, correct VL calculations can be achieved with SPECT

  20. Comparison between different methods of breast implant volume choice and degree of postoperative satisfaction

    Directory of Open Access Journals (Sweden)

    RAFAEL DAIBERT DE SOUZA MOTTA

    2018-02-01

    Full Text Available ABSTRACT Objectives: to assess the degree of patient satisfaction after undergoing breast augmentation and compare three different, easy, inexpensive and universal methods of preoperative choice of breast implant volume. Methods: a prospective study was carried out at University Hospital Pedro Ernesto of State University of Rio de Janeiro, in 94 women from Rio de Janeiro, aged 18 to 49 years, submitted to breast augmentation mammaplasty with breast implant due to hypomastia. All implants were textured, with a round base and high projection and were introduced into the retroglandular space through an inframammary access. The patients were divided into three groups: Control, Silicone and MamaSize®, with 44, 25 and 25 patients, respectively. Satisfaction questionnaires were applied in the pre and postoperative periods by the same evaluator, through the visual analogue scale, in which ‘0’ meant very unsatisfied and ‘100’ very satisfied for the four variables: shape, size, symmetry and consistency. The degree of satisfaction with the surgical scar was also assessed in the postoperative period. Results: when the preoperative and postoperative satisfaction levels were compared, there was a difference in all variables for the three groups, with statistical significance. However, when the postoperative data were compared with each other, there was no significant difference. The degree of satisfaction with the surgical scar was high. Conclusion: the augmentation mammaplasty with breast implant had a high index of satisfaction among patients. However, there was no difference in the degree of satisfaction in the postoperative period between the three methodologies of breast volume measurement.

  1. Imaging and quantification of anomaly volume using an eight-electrode 'hemiarray' EIT reconstruction method.

    Science.gov (United States)

    Sadleir, R J; Zhang, S U; Tucker, A S; Oh, Sungho

    2008-08-01

    Electrical impedance tomography (EIT) is particularly well-suited to applications where its portability, rapid acquisition speed and sensitivity give it a practical advantage over other monitoring or imaging systems. An EIT system's patient interface can potentially be adapted to match the target environment, and thereby increase its utility. It may thus be appropriate to use different electrode positions from those conventionally used in EIT in these cases. One application that may require this is the use of EIT on emergency medicine patients; in particular those who have suffered blunt abdominal trauma. In patients who have suffered major trauma, it is desirable to minimize the risk of spinal cord injury by avoiding lifting them. To adapt EIT to this requirement, we devised and evaluated a new electrode topology (the 'hemiarray') which comprises a set of eight electrodes placed only on the subject's anterior surface. Images were obtained using a two-dimensional sensitivity matrix and weighted singular value decomposition reconstruction. The hemiarray method's ability to quantify bleeding was evaluated by comparing its performance with conventional 2D reconstruction methods using data gathered from a saline phantom. We found that without applying corrections to reconstructed images it was possible to estimate blood volume in a two-dimensional hemiarray case with an uncertainty of around 27 ml. In an approximately 3D hemiarray case, volume prediction was possible with a maximum uncertainty of around 38 ml in the centre of the electrode plane. After application of a QI normalizing filter, average uncertainties in a two-dimensional hemiarray case were reduced to about 15 ml. Uncertainties in the approximate 3D case were reduced to about 30 ml.

  2. Optimal Placement Method of RFID Readers in Industrial Rail Transport for Uneven Rail Traflc Volume Management

    Science.gov (United States)

    Rakhmangulov, Aleksandr; Muravev, Dmitri; Mishkurov, Pavel

    2016-11-01

    The issue of operative data reception on location and movement of railcars is significant the constantly growing requirements of the provision of timely and safe transportation. The technical solution for efficiency improvement of data collection on rail rolling stock is the implementation of an identification system. Nowadays, there are several such systems, distinguished in working principle. In the authors' opinion, the most promising for rail transportation is the RFID technology, proposing the equipping of the railway tracks by the stationary points of data reading (RFID readers) from the onboard sensors on the railcars. However, regardless of a specific type and manufacturer of these systems, their implementation is affiliated with the significant financing costs for large, industrial, rail transport systems, owning the extensive network of special railway tracks with a large number of stations and loading areas. To reduce the investment costs for creation, the identification system of rolling stock on the special railway tracks of industrial enterprises has developed the method based on the idea of priority installation of the RFID readers on railway hauls, where rail traffic volumes are uneven in structure and power, parameters of which is difficult or impossible to predict on the basis of existing data in an information system. To select the optimal locations of RFID readers, the mathematical model of the staged installation of such readers has developed depending on the non-uniformity value of rail traffic volumes, passing through the specific railway hauls. As a result of that approach, installation of the numerous RFID readers at all station tracks and loading areas of industrial railway stations might be not necessary,which reduces the total cost of the rolling stock identification and the implementation of the method for optimal management of transportation process.

  3. Impact of consensus contours from multiple PET segmentation methods on the accuracy of functional volume delineation

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, A. [Saarland University Medical Centre, Department of Nuclear Medicine, Homburg (Germany); Vermandel, M. [U1189 - ONCO-THAI - Image Assisted Laser Therapy for Oncology, University of Lille, Inserm, CHU Lille, Lille (France); CHU Lille, Nuclear Medicine Department, Lille (France); Baillet, C. [CHU Lille, Nuclear Medicine Department, Lille (France); Dewalle-Vignion, A.S. [U1189 - ONCO-THAI - Image Assisted Laser Therapy for Oncology, University of Lille, Inserm, CHU Lille, Lille (France); Modzelewski, R.; Vera, P.; Gardin, I. [Centre Henri-Becquerel and LITIS EA4108, Rouen (France); Massoptier, L.; Parcq, C.; Gibon, D. [AQUILAB, Research and Innovation Department, Loos Les Lille (France); Fechter, T.; Nestle, U. [University Medical Center Freiburg, Department for Radiation Oncology, Freiburg (Germany); German Cancer Consortium (DKTK) Freiburg and German Cancer Research Center (DKFZ), Heidelberg (Germany); Nemer, U. [University Medical Center Freiburg, Department of Nuclear Medicine, Freiburg (Germany)

    2016-05-15

    The aim of this study was to evaluate the impact of consensus algorithms on segmentation results when applied to clinical PET images. In particular, whether the use of the majority vote or STAPLE algorithm could improve the accuracy and reproducibility of the segmentation provided by the combination of three semiautomatic segmentation algorithms was investigated. Three published segmentation methods (contrast-oriented, possibility theory and adaptive thresholding) and two consensus algorithms (majority vote and STAPLE) were implemented in a single software platform (Artiview registered). Four clinical datasets including different locations (thorax, breast, abdomen) or pathologies (primary NSCLC tumours, metastasis, lymphoma) were used to evaluate accuracy and reproducibility of the consensus approach in comparison with pathology as the ground truth or CT as a ground truth surrogate. Variability in the performance of the individual segmentation algorithms for lesions of different tumour entities reflected the variability in PET images in terms of resolution, contrast and noise. Independent of location and pathology of the lesion, however, the consensus method resulted in improved accuracy in volume segmentation compared with the worst-performing individual method in the majority of cases and was close to the best-performing method in many cases. In addition, the implementation revealed high reproducibility in the segmentation results with small changes in the respective starting conditions. There were no significant differences in the results with the STAPLE algorithm and the majority vote algorithm. This study showed that combining different PET segmentation methods by the use of a consensus algorithm offers robustness against the variable performance of individual segmentation methods and this approach would therefore be useful in radiation oncology. It might also be relevant for other scenarios such as the merging of expert recommendations in clinical routine and

  4. Finite volume multigrid method of the planar contraction flow of a viscoelastic fluid

    Science.gov (United States)

    Moatssime, H. Al; Esselaoui, D.; Hakim, A.; Raghay, S.

    2001-08-01

    This paper reports on a numerical algorithm for the steady flow of viscoelastic fluid. The conservative and constitutive equations are solved using the finite volume method (FVM) with a hybrid scheme for the velocities and first-order upwind approximation for the viscoelastic stress. A non-uniform staggered grid system is used. The iterative SIMPLE algorithm is employed to relax the coupled momentum and continuity equations. The non-linear algebraic equations over the flow domain are solved iteratively by the symmetrical coupled Gauss-Seidel (SCGS) method. In both, the full approximation storage (FAS) multigrid algorithm is used. An Oldroyd-B fluid model was selected for the calculation. Results are reported for planar 4:1 abrupt contraction at various Weissenberg numbers. The solutions are found to be stable and smooth. The solutions show that at high Weissenberg number the domain must be long enough. The convergence of the method has been verified with grid refinement. All the calculations have been performed on a PC equipped with a Pentium III processor at 550 MHz. Copyright

  5. Response matrix of regular moderator volumes with 3He detector using Monte Carlo methods

    International Nuclear Information System (INIS)

    Baltazar R, A.; Vega C, H. R.; Ortiz R, J. M.; Solis S, L. O.; Castaneda M, R.; Soto B, T. G.; Medina C, D.

    2017-10-01

    In the last three decades the uses of Monte Carlo methods, for the estimation of physical phenomena associated with the interaction of radiation with matter, have increased considerably. The reason is due to the increase in computing capabilities and the reduction of computer prices. Monte Carlo methods allow modeling and simulating real systems before their construction, saving time and costs. The interaction mechanisms between neutrons and matter are diverse and range from elastic dispersion to nuclear fission; to facilitate the neutrons detection, is necessary to moderate them until reaching electronic equilibrium with the medium at standard conditions of pressure and temperature, in this state the total cross section of the 3 He is large. The objective of the present work was to estimate the response matrix of a proportional detector of 3 He using regular volumes of moderator through Monte Carlo methods. Neutron monoenergetic sources with energies of 10 -9 to 20 MeV and polyethylene moderators of different sizes were used. The calculations were made with the MCNP5 code; the number of stories for each detector-moderator combination was large enough to obtain errors less than 1.5%. We found that for small moderators the highest response is obtained for lower energy neutrons, when increasing the moderator dimension we observe that the response decreases for neutrons of lower energy and increases for higher energy neutrons. The total sum of the responses of each moderator allows obtaining a response close to a constant function. (Author)

  6. Coupled Finite Volume and Finite Element Method Analysis of a Complex Large-Span Roof Structure

    Science.gov (United States)

    Szafran, J.; Juszczyk, K.; Kamiński, M.

    2017-12-01

    The main goal of this paper is to present coupled Computational Fluid Dynamics and structural analysis for the precise determination of wind impact on internal forces and deformations of structural elements of a longspan roof structure. The Finite Volume Method (FVM) serves for a solution of the fluid flow problem to model the air flow around the structure, whose results are applied in turn as the boundary tractions in the Finite Element Method problem structural solution for the linear elastostatics with small deformations. The first part is carried out with the use of ANSYS 15.0 computer system, whereas the FEM system Robot supports stress analysis in particular roof members. A comparison of the wind pressure distribution throughout the roof surface shows some differences with respect to that available in the engineering designing codes like Eurocode, which deserves separate further numerical studies. Coupling of these two separate numerical techniques appears to be promising in view of future computational models of stochastic nature in large scale structural systems due to the stochastic perturbation method.

  7. NUMERICAL SIMULATION OF ELECTRICAL IMPEDANCE TOMOGRAPHY PROBLEM AND STUDY OF APPROACH BASED ON FINITE VOLUME METHOD

    Directory of Open Access Journals (Sweden)

    Ye. S. Sherina

    2014-01-01

    Full Text Available This research has been aimed to carry out a study of peculiarities that arise in a numerical simulation of the electrical impedance tomography (EIT problem. Static EIT image reconstruction is sensitive to a measurement noise and approximation error. A special consideration has been given to reducing of the approximation error, which originates from numerical implementation drawbacks. This paper presents in detail two numerical approaches for solving EIT forward problem. The finite volume method (FVM on unstructured triangular mesh is introduced. In order to compare this approach, the finite element (FEM based forward solver was implemented, which has gained the most popularity among researchers. The calculated potential distribution with the assumed initial conductivity distribution has been compared to the analytical solution of a test Neumann boundary problem and to the results of problem simulation by means of ANSYS FLUENT commercial software. Two approaches to linearized EIT image reconstruction are discussed. Reconstruction of the conductivity distribution is an ill-posed problem, typically requiring a large amount of computation and resolved by minimization techniques. The objective function to be minimized is constructed of measured voltage and calculated boundary voltage on the electrodes. A classical modified Newton type iterative method and the stochastic differential evolution method are employed. A software package has been developed for the problem under investigation. Numerical tests were conducted on simulated data. The obtained results could be helpful to researches tackling the hardware and software issues for medical applications of EIT.

  8. Hybrid finite volume/ finite element method for radiative heat transfer in graded index media

    Science.gov (United States)

    Zhang, L.; Zhao, J. M.; Liu, L. H.; Wang, S. Y.

    2012-09-01

    The rays propagate along curved path determined by the Fermat principle in the graded index medium. The radiative transfer equation in graded index medium (GRTE) contains two specific redistribution terms (with partial derivatives to the angular coordinates) accounting for the effect of the curved ray path. In this paper, the hybrid finite volume with finite element method (hybrid FVM/FEM) (P.J. Coelho, J. Quant. Spectrosc. Radiat. Transf., vol. 93, pp. 89-101, 2005) is extended to solve the radiative heat transfer in two-dimensional absorbing-emitting-scattering graded index media, in which the spatial discretization is carried out using a FVM, while the angular discretization is by a FEM. The FEM angular discretization is demonstrated to be preferable in dealing with the redistribution terms in the GRTE. Two stiff matrix assembly schemes of the angular FEM discretization, namely, the traditional assembly approach and a new spherical assembly approach (assembly on the unit sphere of the solid angular space), are discussed. The spherical assembly scheme is demonstrated to give better results than the traditional assembly approach. The predicted heat flux distributions and temperature distributions in radiative equilibrium are determined by the proposed method and compared with the results available in other references. The proposed hybrid FVM/FEM method can predict the radiative heat transfer in absorbing-emitting-scattering graded index medium with good accuracy.

  9. Hybrid finite volume/ finite element method for radiative heat transfer in graded index media

    International Nuclear Information System (INIS)

    Zhang, L.; Zhao, J.M.; Liu, L.H.; Wang, S.Y.

    2012-01-01

    The rays propagate along curved path determined by the Fermat principle in the graded index medium. The radiative transfer equation in graded index medium (GRTE) contains two specific redistribution terms (with partial derivatives to the angular coordinates) accounting for the effect of the curved ray path. In this paper, the hybrid finite volume with finite element method (hybrid FVM/FEM) (P.J. Coelho, J. Quant. Spectrosc. Radiat. Transf., vol. 93, pp. 89-101, 2005) is extended to solve the radiative heat transfer in two-dimensional absorbing-emitting-scattering graded index media, in which the spatial discretization is carried out using a FVM, while the angular discretization is by a FEM. The FEM angular discretization is demonstrated to be preferable in dealing with the redistribution terms in the GRTE. Two stiff matrix assembly schemes of the angular FEM discretization, namely, the traditional assembly approach and a new spherical assembly approach (assembly on the unit sphere of the solid angular space), are discussed. The spherical assembly scheme is demonstrated to give better results than the traditional assembly approach. The predicted heat flux distributions and temperature distributions in radiative equilibrium are determined by the proposed method and compared with the results available in other references. The proposed hybrid FVM/FEM method can predict the radiative heat transfer in absorbing-emitting-scattering graded index medium with good accuracy.

  10. Foundations of mechanics

    International Nuclear Information System (INIS)

    Zorski, Henryk; Bazanski, Stanislaw; Gutowski, Roman; Slawianowski, Jan; Wilmanski, Krysztof; Wozniak, Czeslaw

    1992-01-01

    In the last 3 decades the field of mechanics has seen spectacular progress due to the demand for applications in problems of cosmology, thermonuclear fusion, metallurgy, etc. This book provides a broad and thorough overview on the foundations of mechanics. It discusses theoretical mechanics and continuum mechanics, as well as phenomenological thermodynamics, quantum mechanics and relativistic mechanics. Each chapter presents the basic physical facts of interest without going into details and derivations and without using advanced mathematical formalism. The first part constitutes a classical exposition of Lagrange's and Hamiltonian's analytical mechanics on which most of the continuum theory is based. The section on continuum mechanics focuses mainly on the axiomatic foundations, with many pointers for further research in this area. Special attention is given to modern continuum thermodynamics, both for the foundations and applications. A section on quantum mechanics is also included, since the phenomenological description of various quantum phenomena is becoming of increasing importance. refs.; figs.; tabs

  11. Hybrid finite-volume/transported PDF method for the simulation of turbulent reactive flows

    Science.gov (United States)

    Raman, Venkatramanan

    A novel computational scheme is formulated for simulating turbulent reactive flows in complex geometries with detailed chemical kinetics. A Probability Density Function (PDF) based method that handles the scalar transport equation is coupled with an existing Finite Volume (FV) Reynolds-Averaged Navier-Stokes (RANS) flow solver. The PDF formulation leads to closed chemical source terms and facilitates the use of detailed chemical mechanisms without approximations. The particle-based PDF scheme is modified to handle complex geometries and grid structures. Grid-independent particle evolution schemes that scale linearly with the problem size are implemented in the Monte-Carlo PDF solver. A novel algorithm, in situ adaptive tabulation (ISAT) is employed to ensure tractability of complex chemistry involving a multitude of species. Several non-reacting test cases are performed to ascertain the efficiency and accuracy of the method. Simulation results from a turbulent jet-diffusion flame case are compared against experimental data. The effect of micromixing model, turbulence model and reaction scheme on flame predictions are discussed extensively. Finally, the method is used to analyze the Dow Chlorination Reactor. Detailed kinetics involving 37 species and 158 reactions as well as a reduced form with 16 species and 21 reactions are used. The effect of inlet configuration on reactor behavior and product distribution is analyzed. Plant-scale reactors exhibit quenching phenomena that cannot be reproduced by conventional simulation methods. The FV-PDF method predicts quenching accurately and provides insight into the dynamics of the reactor near extinction. The accuracy of the fractional time-stepping technique in discussed in the context of apparent multiple-steady states observed in a non-premixed feed configuration of the chlorination reactor.

  12. Physical Foundations of Cosmology

    International Nuclear Information System (INIS)

    Stewart, J M

    2006-01-01

    In 1952, Mme Yvonne Choquet-Bruhat published a major paper, Theoreme d'existence pour certains systemes d'equations aux derivees partielles non lineaires (Acta Math. 88 141-225), which laid the foundation for modern studies of the Cauchy problem in general relativity. The fiftieth anniversary of this event was celebrated with an eponymous Cargese Summer School in 2002. The proceedings of that summer school are summarized electronically (as audio, video, transparencies and lecture notes, where available) on a DVD archive included with this volume, and are also available on the internet. However the organizers decided that a separate volume describing the 'state of the art in mathematical general relativity' would be useful, and this book is the result. It includes some material not covered in the school and excludes some school material which has been covered adequately elsewhere. About one fifth of the book is devoted to a survey of Smoothness at Null Infinity and the Structure of Initial Data by Helmut Friedrich. This is a modern study of gravitational radiation, and the analysis of Einstein's equations. It is extremely helpful to survey all of this material, including some of the latest developments, using a consistent notation. This article is strongly recommended to anyone hoping to gain a foothold in this area. Lars Andersson has surveyed, in The Global Existence Problem in General Relativity, some results and conjectures about the global properties of 3+1-dimensional spacetimes with a compact Cauchy surface. Again it is very useful to have essentially all of the known results presented in a consistent notation. This material is not on the DVD. Yvonne Choquet-Bruhat has contributed a long research paper, Future Complete U(1) Symmetric Einsteinian Spacetimes, the Unpolarized Case. There is a non-linear stability theorem due to her and Vincent Moncrief in which spacetime is of the form M x R where M is a circle bundle over a compact orientable surface of genus

  13. Solution of the square lid-driven cavity flow of a Bingham plastic using the finite volume method

    OpenAIRE

    Syrakos, Alexandros; Georgiou, Georgios C.; Alexandrou, Andreas N.

    2016-01-01

    We investigate the performance of the finite volume method in solving viscoplastic flows. The creeping square lid-driven cavity flow of a Bingham plastic is chosen as the test case and the constitutive equation is regularised as proposed by Papanastasiou [J. Rheol. 31 (1987) 385-404]. It is shown that the convergence rate of the standard SIMPLE pressure-correction algorithm, which is used to solve the algebraic equation system that is produced by the finite volume discretisation, severely det...

  14. Foundations of Risk Analysis

    CERN Document Server

    Aven, Terje

    2012-01-01

    Foundations of Risk Analysis presents the issues core to risk analysis - understanding what risk means, expressing risk, building risk models, addressing uncertainty, and applying probability models to real problems. The author provides the readers with the knowledge and basic thinking they require to successfully manage risk and uncertainty to support decision making. This updated edition reflects recent developments on risk and uncertainty concepts, representations and treatment. New material in Foundations of Risk Analysis includes:An up to date presentation of how to understand, define and

  15. Right ventricular volume determination by two-dimensional echocardiography and radiography in model hearts using a subtraction method

    International Nuclear Information System (INIS)

    Krebs, W.; Erbel, R.; Schweizer, P.; Richter, H.A.; Massberg, I.; Meyer, J.; Effert, S.; Henn, G.

    1982-01-01

    The irregularity and complexity of the right ventricle is the reason why no accurate method for right ventricular volume determination exists. A new method for right ventricular volume determination particularly for two-dimensional echocardiography was developed - it is called subtraction method - and was compared with the pyramid and Simpson's methods. The partial volume of the left ventricle and septum was subtracted from total volume of right and left ventricle including interventricular septum. Thus right ventricular volume resulted. Total and partial volume were computer-assisted calculated by use of biplane methods, preferably Simpson's rule. The method was proved with thinwall silicon-rubber model hearts of the left and right ventricle. Two orthogonal planes in the long-axis were filmed by radiography or scanned in a water bath by two-dimensional echocardiography equivalent to RAO and LAO-projections of cineangiocardiograms or to four- and two-chamber views of apical two-dimensional echocardiograms. For calculation of the major axes of the elliptical sections, summed up by Simpson's rule, they were derived from the LAO-projection and the four-chamber view, respectively, the minor axis approximated from the RAO-projection and the two-chamber view. For comparison of direct-measured volume and two-dimensional echocardiographically determined volume, regression equation was given by y = 1.01 x - 3.2, correlation-coefficient, r = 0.977, and standard error of estimate (SEE) +-10.5 ml. For radiography, regression equation was y = 0.909 x + 13.3, r = 0.983, SEE = +-8.0 ml. For pyramid method and Simpson's rule, higher standard errors and lower correlation coefficients were found. Between radiography and two-dimensional echocardiography a mean difference of 4.3 +- 13.2 ml, using subtraction method, and -10.2 +- 22.9 ml, using pyramid method, as well as -0.6 +- 18.5 ml, using Simpson's rule, were calculated for right ventricular volume measurements. (orig./APR) [de

  16. An element-based finite-volume method approach for naturally fractured compositional reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Marcondes, Francisco [Federal University of Ceara, Fortaleza (Brazil). Dept. of Metallurgical Engineering and Material Science], e-mail: marcondes@ufc.br; Varavei, Abdoljalil; Sepehrnoori, Kamy [The University of Texas at Austin (United States). Petroleum and Geosystems Engineering Dept.], e-mails: varavei@mail.utexas.edu, kamys@mail.utexas.edu

    2010-07-01

    An element-based finite-volume approach in conjunction with unstructured grids for naturally fractured compositional reservoir simulation is presented. In this approach, both the discrete fracture and the matrix mass balances are taken into account without any additional models to couple the matrix and discrete fractures. The mesh, for two dimensional domains, can be built of triangles, quadrilaterals, or a mix of these elements. However, due to the available mesh generator to handle both matrix and discrete fractures, only results using triangular elements will be presented. The discrete fractures are located along the edges of each element. To obtain the approximated matrix equation, each element is divided into three sub-elements and then the mass balance equations for each component are integrated along each interface of the sub-elements. The finite-volume conservation equations are assembled from the contribution of all the elements that share a vertex, creating a cell vertex approach. The discrete fracture equations are discretized only along the edges of each element and then summed up with the matrix equations in order to obtain a conservative equation for both matrix and discrete fractures. In order to mimic real field simulations, the capillary pressure is included in both matrix and discrete fracture media. In the implemented model, the saturation field in the matrix and discrete fractures can be different, but the potential of each phase in the matrix and discrete fracture interface needs to be the same. The results for several naturally fractured reservoirs are presented to demonstrate the applicability of the method. (author)

  17. Methods for quantitative measurement of tooth wear using the area and volume of virtual model cusps.

    Science.gov (United States)

    Kim, Soo-Hyun; Park, Young-Seok; Kim, Min-Kyoung; Kim, Sulhee; Lee, Seung-Pyo

    2018-04-01

    Clinicians must examine tooth wear to make a proper diagnosis. However, qualitative methods of measuring tooth wear have many disadvantages. Therefore, this study aimed to develop and evaluate quantitative parameters using the cusp area and volume of virtual dental models. The subjects of this study were the same virtual models that were used in our former study. The same age group classification and new tooth wear index (NTWI) scoring system were also reused. A virtual occlusal plane was generated with the highest cusp points and lowered vertically from 0.2 to 0.8 mm to create offset planes. The area and volume of each cusp was then measured and added together. In addition to the former analysis, the differential features of each cusp were analyzed. The scores of the new parameters differentiated the age and NTWI groups better than those analyzed in the former study. The Spearman ρ coefficients between the total area and the area of each cusp also showed higher scores at the levels of 0.6 mm (0.6A) and 0.8A. The mesiolingual cusp (MLC) showed a statistically significant difference ( P <0.01) from the other cusps in the paired t -test. Additionally, the MLC exhibited the highest percentage of change at 0.6A in some age and NTWI groups. Regarding the age groups, the MLC showed the highest score in groups 1 and 2. For the NTWI groups, the MLC was not significantly different in groups 3 and 4. These results support the proposal that the lingual cusp exhibits rapid wear because it serves as a functional cusp. Although this study has limitations due to its cross-sectional nature, it suggests better quantitative parameters and analytical tools for the characteristics of cusp wear.

  18. Evaluation of the reconstruction method and effect of partial volume in brain scintiscanning

    International Nuclear Information System (INIS)

    Pinheiro, Monica Araujo

    2016-01-01

    Alzheimer's disease is a neurodegenerative disorder, on which occurs a progressive and irreversible destruction of neurons. According to the World Health Organization (WHO) 35.6 million people are living with dementia, being recommended that governments prioritize early diagnosis techniques. Laboratory and psychological tests for cognitive assessment are conducted and further complemented by neurological imaging from nuclear medicine exams in order to establish an accurate diagnosis. The image quality evaluation and reconstruction process effects are important tools in clinical routine. In the present work, these quality parameters were studied, and the effects of partial volume (PVE) for lesions of different sizes and geometries that are attributed to the limited resolution of the equipment. In dementia diagnosis, this effect can be confused with intake losses due to cerebral cortex atrophy. The evaluation was conducted by two phantoms of different shapes as suggested by (a) American College of Radiology (ACR) and (b) National Electrical Manufacturers Association (NEMA) for Contrast, Contrast-to-Noise Ratio (CNR) and Recovery Coefficient (RC) calculation versus lesions shape and size. Technetium-99m radionuclide was used in a local brain scintigraphy protocol, for proportions lesion to background of 2:1, 4:1, 6:1, 8:1 and 10:1. Fourteen reconstruction methods were used for each concentration applying different filters and algorithms. Before the analysis of all image properties, the conclusion is that the predominant effect is the partial volume, leading to errors of measurement of more than 80%. Furthermore, it was demonstrate that the most effective method of reconstruction is FBP with Metz filter, providing better contrast and contrast to noise ratio results. In addition, this method shows the best Recovery Coefficients correction for each lesion. The ACR phantom showed the best results assigned to a more precise reconstruction of a cylinder, which does not

  19. Variation in Results of Volume Measurements of Stumps of Lower-Limb Amputees : A Comparison of 4 Methods

    NARCIS (Netherlands)

    de Boer-Wilzing, Vera G.; Bolt, Arjen; Geertzen, Jan H.; Emmelot, Cornelis H.; Baars, Erwin C.; Dijkstra, Pieter U.

    de Boer-Wilzing VG, Bolt A, Geertzen JH, Emmelot CH, Baars EC, Dijkstra PU. Variation in results of volume measurements of stumps of lower-limb amputees: a comparison of 4 methods. Arch Phys Med Rehabil 2011;92:941-6. Objective: To analyze the reliability of 4 methods (water immersion,

  20. A rapid method for estimation of Pu-isotopes in urine samples using high volume centrifuge.

    Science.gov (United States)

    Kumar, Ranjeet; Rao, D D; Dubla, Rupali; Yadav, J R

    2017-07-01

    The conventional radio-analytical technique used for estimation of Pu-isotopes in urine samples involves anion exchange/TEVA column separation followed by alpha spectrometry. This sequence of analysis consumes nearly 3-4 days for completion. Many a times excreta analysis results are required urgently, particularly under repeat and incidental/emergency situations. Therefore, there is need to reduce the analysis time for the estimation of Pu-isotopes in bioassay samples. This paper gives the details of standardization of a rapid method for estimation of Pu-isotopes in urine samples using multi-purpose centrifuge, TEVA resin followed by alpha spectrometry. The rapid method involves oxidation of urine samples, co-precipitation of plutonium along with calcium phosphate followed by sample preparation using high volume centrifuge and separation of Pu using TEVA resin. Pu-fraction was electrodeposited and activity estimated using 236 Pu tracer recovery by alpha spectrometry. Ten routine urine samples of radiation workers were analyzed and consistent radiochemical tracer recovery was obtained in the range 47-88% with a mean and standard deviation of 64.4% and 11.3% respectively. With this newly standardized technique, the whole analytical procedure is completed within 9h (one working day hour). Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Analysis of one-dimensional nonequilibrium two-phase flow using control volume method

    International Nuclear Information System (INIS)

    Minato, Akihiko; Naitoh, Masanori

    1987-01-01

    A one-dimensional numerical analysis model was developed for prediction of rapid flow transient behavior involving boiling. This model was based on six conservation equations of time averaged parameters of gas and liquid behavior. These equations were solved by using a control volume method with an explicit time integration. This model did not use staggered mesh scheme, which had been commonly used in two-phase flow analysis. Because void fraction and velocity of each phase were defined at the same location in the present model, effects of void fraction on phase velocity calculation were treated directly without interpolation. Though non-staggered mesh scheme was liable to cause numerical instability with zigzag pressure field, stability was achieved by employing the Godunov method. In order to verify the present analytical model, Edwards' pipe blow down and Zaloudek's initially subcooled critical two-phase flow experiments were analyzed. Stable solutions were obtained for rarefaction wave propagation with boiling and transient two-phase flow behavior in a broken pipe by using this model. (author)

  2. Sensitivity and uncertainty analyses applied to criticality safety validation, methods development. Volume 1

    International Nuclear Information System (INIS)

    Broadhead, B.L.; Hopper, C.M.; Childs, R.L.; Parks, C.V.

    1999-01-01

    This report presents the application of sensitivity and uncertainty (S/U) analysis methodologies to the code/data validation tasks of a criticality safety computational study. Sensitivity and uncertainty analysis methods were first developed for application to fast reactor studies in the 1970s. This work has revitalized and updated the available S/U computational capabilities such that they can be used as prototypic modules of the SCALE code system, which contains criticality analysis tools currently used by criticality safety practitioners. After complete development, simplified tools are expected to be released for general use. The S/U methods that are presented in this volume are designed to provide a formal means of establishing the range (or area) of applicability for criticality safety data validation studies. The development of parameters that are analogous to the standard trending parameters forms the key to the technique. These parameters are the D parameters, which represent the differences by group of sensitivity profiles, and the ck parameters, which are the correlation coefficients for the calculational uncertainties between systems; each set of parameters gives information relative to the similarity between pairs of selected systems, e.g., a critical experiment and a specific real-world system (the application)

  3. Numerical method for time-dependent localized corrosion analysis with moving boundaries by combining the finite volume method and voxel method

    International Nuclear Information System (INIS)

    Onishi, Yuki; Takiyasu, Jumpei; Amaya, Kenji; Yakuwa, Hiroshi; Hayabusa, Keisuke

    2012-01-01

    Highlights: ► A novel numerical method to analyze time dependent localized corrosion is developed. ► It takes electromigration, mass diffusion, chemical reactions, and moving boundaries. ► Our method perfectly satisfies the conservation of mass and electroneutrality. ► The behavior of typical crevice corrosion is successfully simulated. ► Both verification and validation of our method are carried out. - Abstract: A novel numerical method for time-dependent localized corrosion analysis is presented. Electromigration, mass diffusion, chemical reactions, and moving boundaries are considered in the numerical simulation of localized corrosion of engineering alloys in an underwater environment. Our method combines the finite volume method (FVM) and the voxel method. The FVM is adopted in the corrosion rate calculation so that the conservation of mass is satisfied. A newly developed decoupled algorithm with a projection method is introduced in the FVM to decouple the multiphysics problem into the electrostatic, mass transport, and chemical reaction analyses with electroneutrality maintained. The polarization curves for the corroding metal are used as boundary conditions for the metal surfaces to calculate the corrosion rates. The voxel method is adopted in updating the moving boundaries of cavities without remeshing and mesh-to-mesh solution mapping. Some modifications of the standard voxel method, which represents the boundaries as zigzag-shaped surfaces, are introduced to generate smooth surfaces. Our method successfully reproduces the numerical and experimental results of a capillary electrophoresis problem. Furthermore, the numerical results are qualitatively consistent with the experimental results for several examples of crevice corrosion.

  4. Fluorescence Exclusion: A Simple Method to Assess Projected Surface, Volume and Morphology of Red Blood Cells Stored in Blood Bank

    Directory of Open Access Journals (Sweden)

    Camille Roussel

    2018-05-01

    Full Text Available Red blood cells (RBC ability to circulate is closely related to their surface area-to-volume ratio. A decrease in this ratio induces a decrease in RBC deformability that can lead to their retention and elimination in the spleen. We recently showed that a subpopulation of “small RBC” with reduced projected surface area accumulated upon storage in blood bank concentrates, but data on the volume of these altered RBC are lacking. So far, single cell measurement of RBC volume has remained a challenging task achieved by a few sophisticated methods some being subject to potential artifacts. We aimed to develop a reproducible and ergonomic method to assess simultaneously RBC volume and morphology at the single cell level. We adapted the fluorescence exclusion measurement of volume in nucleated cells to the measurement of RBC volume. This method requires no pre-treatment of the cell and can be performed in physiological or experimental buffer. In addition to RBC volume assessment, brightfield images enabling a precise definition of the morphology and the measurement of projected surface area can be generated simultaneously. We first verified that fluorescence exclusion is precise, reproducible and can quantify volume modifications following morphological changes induced by heating or incubation in non-physiological medium. We then used the method to characterize RBC stored for 42 days in SAG-M in blood bank conditions. Simultaneous determination of the volume, projected surface area and morphology allowed to evaluate the surface area-to-volume ratio of individual RBC upon storage. We observed a similar surface area-to-volume ratio in discocytes (D and echinocytes I (EI, which decreased in EII (7% and EIII (24%, sphero-echinocytes (SE; 41% and spherocytes (S; 47%. If RBC dimensions determine indeed the ability of RBC to cross the spleen, these modifications are expected to induce the rapid splenic entrapment of the most morphologically altered RBC

  5. Lymphoma Research Foundation

    Science.gov (United States)

    ... Follow LRF Watch LRF Contact Us National Headquarters Wall Street Plaza 88 Pine Street, Suite 2400 | New York, NY 10005 212-349-2910 | 212-349-2886 Fax LRF@lymphoma.org LRF Helpline 800-500-9976 Helpline@lymphoma.org © 2012 Lymphoma Research Foundation | Privacy Policy

  6. Impedance of Bucket Foundations

    DEFF Research Database (Denmark)

    Andersen, Lars; Ibsen, Lars Bo; Liingaard, Morten

    2008-01-01

    Modern offshore wind turbines are flexible structures with natural frequencies near the excitation frequencies related to wave and wind-induced loads. In order to obtain a reliable prediction of the structural response, the dynamic stiffness of the foundation must be evaluated accurately. This pa...

  7. BrightFocus Foundation

    Science.gov (United States)

    ... About BrightFocus Foundation Featured Content BrightFocus: Investing in Science to Save Mind and Sight We're here to help. Explore ... recognition is very important. Monday, November 6, 2017 New Diagnosis? Managing a mind and sight disease is a journey. And you’ ...

  8. Foundations of factor analysis

    CERN Document Server

    Mulaik, Stanley A

    2009-01-01

    Introduction Factor Analysis and Structural Theories Brief History of Factor Analysis as a Linear Model Example of Factor AnalysisMathematical Foundations for Factor Analysis Introduction Scalar AlgebraVectorsMatrix AlgebraDeterminants Treatment of Variables as Vectors Maxima and Minima of FunctionsComposite Variables and Linear Transformations Introduction Composite Variables Unweighted Composite VariablesDifferentially Weighted Composites Matrix EquationsMulti

  9. American Porphyria Foundation

    Science.gov (United States)

    ... Nicole Castelano Gregary Edwards Megan Parrish ~ How the dog I didn't want became the dog I'd always dreamed of Darnisha Davenport Liz ... or through the site for commercial or public purposes. The American Porphyria Foundation (APF) Tax Forms 990 ...

  10. Foundations of powder metallurgy

    International Nuclear Information System (INIS)

    Libenson, G.A.

    1987-01-01

    Consideration is being given to physicochemical foundations and technology of metal powders, moulding and sintering of bars, made of them or their mixtures with nonmetal powders. Data on he design of basic equipment used in the processes of powder metallurgy and its servicing are presented. General requirements of safety engineering when fabricating metal powders and products of them are mentioned

  11. Numerical Methods in Atmospheric and Oceanic Modelling: The Andre J. Robert Memorial Volume

    Science.gov (United States)

    Rosmond, Tom

    Most people, even including some in the scientific community, do not realize how much the weather forecasts they use to guide the activities of their daily lives depend on very complex mathematics and numerical methods that are the basis of modern numerical weather prediction (NWP). André Robert (1929-1993), to whom Numerical Methods in Atmospheric and Oceanic Modelling is dedicated, had a career that contributed greatly to the growth of NWP and the role that the atmospheric computer models of NWP play in our society. There are probably no NWP models running anywhere in the world today that do not use numerical methods introduced by Robert, and those of us who work with and use these models everyday are indebted to him.The first two chapters of the volume are chronicles of Robert's life and career. The first is a 1987 interview by Harold Ritchie, one of Robert's many proteges and colleagues at the Canadian Atmospheric Environment Service. The interview traces Robert's life from his birth in New York to French Canadian parents, to his emigration to Quebec at an early age, his education and early employment, and his rise in stature as one of the preeminent research meteorologists of our time. An amusing anecdote he relates is his impression of weather forecasts while he was considering his first job as a meteorologist in the early 1950s. A newspaper of the time placed the weather forecast and daily horoscope side by side, and Robert regarded each to have a similar scientific basis. Thankfully he soon realized there was a difference between the two, and his subsequent career certainly confirmed the distinction.

  12. New methods to interpolate large volume of data from points or particles (Mesh-Free) methods application for its scientific visualization

    International Nuclear Information System (INIS)

    Reyes Lopez, Y.; Yervilla Herrera, H.; Viamontes Esquivel, A.; Recarey Morfa, C. A.

    2009-01-01

    In the following paper we developed a new method to interpolate large volumes of scattered data, focused mainly on the results of the Mesh free Methods, Points Methods and the Particles Methods application. Through this one, we use local radial basis function as interpolating functions. We also use over-tree as the data structure that allows to accelerate the localization of the data that influences to interpolate the values at a new point, speeding up the application of scientific visualization techniques to generate images from large data volumes from the application of Mesh-free Methods, Points and Particle Methods, in the resolution of diverse models of physics-mathematics. As an example, the results obtained after applying this method using the local interpolation functions of Shepard are shown. (Author) 22 refs

  13. On Foundation Improvement By Sand Replacement | Abam | Global ...

    African Journals Online (AJOL)

    This paper describes a simple foundation improvement method involving the replacement of poor foundation bearing soils with sand and the resultant improvement in bearing capacity and the minimization of settlement at the site of a large storage tank. Minimum thickness of sand replacement for various foundation loads ...

  14. Towards Ontological Foundations for Agent Modeling Concepts using UFO

    NARCIS (Netherlands)

    Guizzardi, G.; Wagner, Gerd

    Foundational ontologies provide the basic concepts upon which any domain-specific ontology is built. This paper presents a new foundational ontology, UFO, and shows how it can be used as a foundation of agent concepts and for evaluating agent-oriented modeling methods. UFO is derived from a

  15. Validation of hippocampal volumes measured using a manual method and two automated methods (FreeSurfer and IBASPM) in chronic major depressive disorder

    Energy Technology Data Exchange (ETDEWEB)

    Tae, Woo Suk; Lee, Kang Uk; Nam, Eui-Cheol; Kim, Keun Woo [Kangwon National University College of Medicine, Neuroscience Research Institute, Kangwon (Korea); Kim, Sam Soo [Kangwon National University College of Medicine, Neuroscience Research Institute, Kangwon (Korea); Kangwon National University Hospital, Department of Radiology, Kangwon-do (Korea)

    2008-07-15

    To validate the usefulness of the packages available for automated hippocampal volumetry, we measured hippocampal volumes using one manual and two recently developed automated volumetric methods. The study included T1-weighted magnetic resonance imaging (MRI) of 21 patients with chronic major depressive disorder (MDD) and 20 normal controls. Using coronal turbo field echo (TFE) MRI with a slice thickness of 1.3 mm, the hippocampal volumes were measured using three methods: manual volumetry, surface-based parcellation using FreeSurfer, and individual atlas-based volumetry using IBASPM. In addition, the intracranial cavity volume (ICV) was measured manually. The absolute left hippocampal volume of the patients with MDD measured using all three methods was significantly smaller than the left hippocampal volume of the normal controls (manual P=0.029, FreeSurfer P=0.035, IBASPM P=0.018). After controlling for the ICV, except for the right hippocampal volume measured using FreeSurfer, both measured hippocampal volumes of the patients with MDD were significantly smaller than the measured hippocampal volumes of the normal controls (right manual P=0.019, IBASPM P=0.012; left manual P=0.003, FreeSurfer P=0.010, IBASPM P=0.002). In the intrarater reliability test, the intraclass correlation coefficients (ICCs) were all excellent (manual right 0.947, left 0.934; FreeSurfer right 1.000, left 1.000; IBASPM right 1.000, left 1.000). In the test of agreement between the volumetric methods, the ICCs were right 0.846 and left 0.848 (manual and FreeSurfer), and right 0.654 and left 0.717 (manual and IBASPM). The automated hippocampal volumetric methods showed good agreement with manual hippocampal volumetry, but the volume measured using FreeSurfer was 35% larger and the agreement was questionable with IBASPM. Although the automated methods could detect hippocampal atrophy in the patients with MDD, the results indicate that manual hippocampal volumetry is still the gold standard

  16. Validation of hippocampal volumes measured using a manual method and two automated methods (FreeSurfer and IBASPM) in chronic major depressive disorder

    International Nuclear Information System (INIS)

    Tae, Woo Suk; Lee, Kang Uk; Nam, Eui-Cheol; Kim, Keun Woo; Kim, Sam Soo

    2008-01-01

    To validate the usefulness of the packages available for automated hippocampal volumetry, we measured hippocampal volumes using one manual and two recently developed automated volumetric methods. The study included T1-weighted magnetic resonance imaging (MRI) of 21 patients with chronic major depressive disorder (MDD) and 20 normal controls. Using coronal turbo field echo (TFE) MRI with a slice thickness of 1.3 mm, the hippocampal volumes were measured using three methods: manual volumetry, surface-based parcellation using FreeSurfer, and individual atlas-based volumetry using IBASPM. In addition, the intracranial cavity volume (ICV) was measured manually. The absolute left hippocampal volume of the patients with MDD measured using all three methods was significantly smaller than the left hippocampal volume of the normal controls (manual P=0.029, FreeSurfer P=0.035, IBASPM P=0.018). After controlling for the ICV, except for the right hippocampal volume measured using FreeSurfer, both measured hippocampal volumes of the patients with MDD were significantly smaller than the measured hippocampal volumes of the normal controls (right manual P=0.019, IBASPM P=0.012; left manual P=0.003, FreeSurfer P=0.010, IBASPM P=0.002). In the intrarater reliability test, the intraclass correlation coefficients (ICCs) were all excellent (manual right 0.947, left 0.934; FreeSurfer right 1.000, left 1.000; IBASPM right 1.000, left 1.000). In the test of agreement between the volumetric methods, the ICCs were right 0.846 and left 0.848 (manual and FreeSurfer), and right 0.654 and left 0.717 (manual and IBASPM). The automated hippocampal volumetric methods showed good agreement with manual hippocampal volumetry, but the volume measured using FreeSurfer was 35% larger and the agreement was questionable with IBASPM. Although the automated methods could detect hippocampal atrophy in the patients with MDD, the results indicate that manual hippocampal volumetry is still the gold standard

  17. 29 CFR 779.342 - Methods of computing annual volume of sales.

    Science.gov (United States)

    2010-07-01

    ... STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Exemptions for Certain Retail or Service...) of the Act are specified in terms of the “annual dollar volume of sales” of goods or of services (or... annual dollar volume before deduction of those taxes which are excluded in determining whether the $250...

  18. Comparison of three methods for registration of abdominal/pelvic volume data sets from functional-anatomic scans

    Science.gov (United States)

    Mahmoud, Faaiza; Ton, Anthony; Crafoord, Joakim; Kramer, Elissa L.; Maguire, Gerald Q., Jr.; Noz, Marilyn E.; Zeleznik, Michael P.

    2000-06-01

    The purpose of this work was to evaluate three volumetric registration methods in terms of technique, user-friendliness and time requirements. CT and SPECT data from 11 patients were interactively registered using: a 3D method involving only affine transformation; a mixed 3D - 2D non-affine (warping) method; and a 3D non-affine (warping) method. In the first method representative isosurfaces are generated from the anatomical images. Registration proceeds through translation, rotation, and scaling in all three space variables. Resulting isosurfaces are fused and quantitative measurements are possible. In the second method, the 3D volumes are rendered co-planar by performing an oblique projection. Corresponding landmark pairs are chosen on matching axial slice sets. A polynomial warp is then applied. This method has undergone extensive validation and was used to evaluate the results. The third method employs visualization tools. The data model allows images to be localized within two separate volumes. Landmarks are chosen on separate slices. Polynomial warping coefficients are generated and data points from one volume are moved to the corresponding new positions. The two landmark methods were the least time consuming (10 to 30 minutes from start to finish), but did demand a good knowledge of anatomy. The affine method was tedious and required a fair understanding of 3D geometry.

  19. Comparison of six methods of segmentation of tumor volume on the {sup 18}F-F.D.G. PET scan with reference histological volume in non small cell bronchopulmonary cancers; Comparaison de six methodes de segmentation du volume tumoral sur la {sup 18}F-FDG TEP-TDM avec le volume de reference anatomopathologique dans les cancers bronchopulmonaires non a petites cellules

    Energy Technology Data Exchange (ETDEWEB)

    Venel, Y.; Garhi, H.; Baulieu, J.L.; Prunier-Aesch, C. [CHRU de Tours-Bretonneau, Service de Medecine Nucleaire, 37 - Tours (France); Muret, A. de [CHRU de Tours-Bretonneau, Service de Radiotherapie, 37 - Tours (France); Barillot, I. [CHRU de Tours-Bretonneau, Service d' Anatomopathologie, 37 - Tours (France)

    2008-06-15

    The {sup 18}F-F.D.G. PET has demonstrated its importance in oncology, for initial extension and efficacy of anti tumoral therapeutics. Several studies have attempted to prove its utility to define tumoral volumes for conformational radiotherapy in non small cell lung cancers. Some authors have suggested the use of threshold of tumor intensity uptake with 40 or 50% of maximal intensity. Black et al. have determined contouring with linear regression formula of mean semi-quantitative index of tumor uptake (standard uptake value): SUV{sub threshold} = 0.307 Sub{sub average} + 0.588. Nestle et al. have taken into account the background noise intensity and mean intensity of the tumor: I{sub threshold} = {beta} I{sub average} +I{sub noise} with {beta} 0.15. Our study was done in collaboration with Inserm U618 team and has compared volumes defined on PET scan defined according to different methods based on intensity or S.U.V. to the tumour volume determined on CT scan by radio physicist. We have compared those volumes with histological volume that we considered for reference. Four patients have been included. They had {sup 18}F-F.D.G. PET scan followed by complete tumoral removal surgery. Specific histological procedure allowed to define complete size of the tumor in re expanded lung. Comparatively to pathology, the volumes obtained using I{sub max} 40 and I{sub max} 50 are all underestimated. The volumes defined by Black's et al. method are under evaluated for the two largest tumours (15.8% to 22%) and overestimated for the two smallest ones (17.9 to 82.9%). Nestle's et al. method, using {beta} = 0.15, correctly estimates two tumor volumes over 2 cm, but overestimates the two small tumors (79.6 to 124%). Finally, the corrected Nestle's et al. formula (using {beta} = 0.264) overestimates three tumours. Volumes defined on CT scan by radio physicist are correct for one lesion, underestimated for one and overestimated for two other ones (44 and 179.5%). Nestle

  20. The role of geophysical ERT method to evaluate the leakproofness of diapragm wall of deep foundation trenches on the example of the construction of retail and office complex in Lublin, Poland

    Directory of Open Access Journals (Sweden)

    Pacanowski Grzegorz

    2014-12-01

    Full Text Available This paper addresses the problem of assessing the leakproofness of the bottom of a deep foundation trench, secured by cavity wall, using geophysical methods of electrical resistivity tomography. The study was conducted on a large construction project in Lublin, in a place where there are complicated soil-water conditions: the groundwater level is above the proposed depth of foundation trench, the subsoil is heterogeneous, and there are karsted and weathered carbonate sediments with confined aquifer below the bottom of the trench. A hydraulic fracture occurred at the bottom of the trench during the engineering works, which caused the water flow into the trench. In order to recognize the soil-water conditions the first stage of geophysical measurements of electrical resistivity tomography (ERT was made. The applied methodology allowed to determine the extent of the hydraulic fracture zone within the bottom of foundation trench. In order to assess the leakproofness of Diaphragm Wall the geophysical ERT measurements were repeated (stage 2 A clear reduction in the value of the electrical resistivity of soils in the area of hydraulic fracture was caused by clay injection. The results of ERT measurements are discussed and graphically presented.

  1. Study of scattering cross section of a plasma column using Green's function volume integral equation method

    Science.gov (United States)

    Soltanmoradi, Elmira; Shokri, Babak

    2017-05-01

    In this article, the electromagnetic wave scattering from plasma columns with inhomogeneous electron density distribution is studied by the Green's function volume integral equation method. Due to the ready production of such plasmas in the laboratories and their practical application in various technological fields, this study tries to find the effects of plasma parameters such as the electron density, radius, and pressure on the scattering cross-section of a plasma column. Moreover, the incident wave frequency influence of the scattering pattern is demonstrated. Furthermore, the scattering cross-section of a plasma column with an inhomogeneous collision frequency profile is calculated and the effect of this inhomogeneity is discussed first in this article. These results are especially used to determine the appropriate conditions for radar cross-section reduction purposes. It is shown that the radar cross-section of a plasma column reduces more for a larger collision frequency, for a relatively lower plasma frequency, and also for a smaller radius. Furthermore, it is found that the effect of the electron density on the scattering cross-section is more obvious in comparison with the effect of other plasma parameters. Also, the plasma column with homogenous collision frequency can be used as a better shielding in contrast to its inhomogeneous counterpart.

  2. Two-dimensional transient thermal analysis of a fuel rod by finite volume method

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Rhayanne Yalle Negreiros; Silva, Mário Augusto Bezerra da; Lira, Carlos Alberto de Oliveira, E-mail: ryncosta@gmail.com, E-mail: mabs500@gmail.com, E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear

    2017-07-01

    One of the greatest concerns when studying a nuclear reactor is the warranty of safe temperature limits all over the system at all time. The preservation of core structure along with the constraint of radioactive material into a controlled system are the main focus during the operation of a reactor. The purpose of this paper is to present the temperature distribution for a nominal channel of the AP1000 reactor developed by Westinghouse Co. during steady-state and transient operations. In the analysis, the system was subjected to normal operation conditions and then to blockages of the coolant flow. The time necessary to achieve a new safe stationary stage (when it was possible) was presented. The methodology applied in this analysis was based on a two-dimensional survey accomplished by the application of Finite Volume Method (FVM). A steady solution is obtained and compared with an analytical analysis that disregard axial heat transport to determine its relevance. The results show the importance of axial heat transport consideration in this type of study. A transient analysis shows the behavior of the system when submitted to coolant blockage at channel's entrance. Three blockages were simulated (10%, 20% and 30%) and the results show that, for a nominal channel, the system can still be considerate safe (there's no bubble formation until that point). (author)

  3. A METHOD OF RAPID CULTIVATION OF RADISH SEED PLANTS IN PLASTIC POTS OF SMALL-VOLUME

    Directory of Open Access Journals (Sweden)

    V. A. Stepanov

    2017-01-01

    Full Text Available The development of cheap and rapid breeding methods to breed  the lines used for  hybrid  F1  production  is a very actual task. The study was carried out with a use of radish varieties originated at VNIISSOK and breeding lines obtained by crossing components of different origin with male  sterility  in  winter  glass  greenhouse.  The  mother plants were grown  on the trays Plantec 64, while seedplants were grown in plastic pots of 1 liter capacity. The some morphobiological features such as the small habitus of see-plant; smaller number of secondary branching and absence of following branches; and consequently, the low yield of seeds were revealed in seed-plants of radish being grown in plastic pots. The period of ontogenesis in radish at first winter-spring rotation with this cultivation approach was reduced to 92 days. At the second summer-autumn rotation with additional lighting the duration of period of ontogenesis was essentially shorter than in the first rotation.  The utilization of  small-volume capacities in winter glass greenhouse to grow the radish seed-plants has permitted to produce two generations a year.

  4. Optimized waveform relaxation domain decomposition method for discrete finite volume non stationary convection diffusion equation

    International Nuclear Information System (INIS)

    Berthe, P.M.

    2013-01-01

    In the context of nuclear waste repositories, we consider the numerical discretization of the non stationary convection diffusion equation. Discontinuous physical parameters and heterogeneous space and time scales lead us to use different space and time discretizations in different parts of the domain. In this work, we choose the discrete duality finite volume (DDFV) scheme and the discontinuous Galerkin scheme in time, coupled by an optimized Schwarz waveform relaxation (OSWR) domain decomposition method, because this allows the use of non-conforming space-time meshes. The main difficulty lies in finding an upwind discretization of the convective flux which remains local to a sub-domain and such that the multi domain scheme is equivalent to the mono domain one. These difficulties are first dealt with in the one-dimensional context, where different discretizations are studied. The chosen scheme introduces a hybrid unknown on the cell interfaces. The idea of up winding with respect to this hybrid unknown is extended to the DDFV scheme in the two-dimensional setting. The well-posedness of the scheme and of an equivalent multi domain scheme is shown. The latter is solved by an OSWR algorithm, the convergence of which is proved. The optimized parameters in the Robin transmission conditions are obtained by studying the continuous or discrete convergence rates. Several test-cases, one of which inspired by nuclear waste repositories, illustrate these results. (author) [fr

  5. Development and Analysis of Volume Multi-Sphere Method Model Generation using Electric Field Fitting

    Science.gov (United States)

    Ingram, G. J.

    Electrostatic modeling of spacecraft has wide-reaching applications such as detumbling space debris in the Geosynchronous Earth Orbit regime before docking, servicing and tugging space debris to graveyard orbits, and Lorentz augmented orbits. The viability of electrostatic actuation control applications relies on faster-than-realtime characterization of the electrostatic interaction. The Volume Multi-Sphere Method (VMSM) seeks the optimal placement and radii of a small number of equipotential spheres to accurately model the electrostatic force and torque on a conducting space object. Current VMSM models tuned using force and torque comparisons with commercially available finite element software are subject to the modeled probe size and numerical errors of the software. This work first investigates fitting of VMSM models to Surface-MSM (SMSM) generated electrical field data, removing modeling dependence on probe geometry while significantly increasing performance and speed. A proposed electric field matching cost function is compared to a force and torque cost function, the inclusion of a self-capacitance constraint is explored and 4 degree-of-freedom VMSM models generated using electric field matching are investigated. The resulting E-field based VMSM development framework is illustrated on a box-shaped hub with a single solar panel, and convergence properties of select models are qualitatively analyzed. Despite the complex non-symmetric spacecraft geometry, elegantly simple 2-sphere VMSM solutions provide force and torque fits within a few percent.

  6. A multi-step dealloying method to produce nanoporous gold with no volume change and minimal cracking

    Energy Technology Data Exchange (ETDEWEB)

    Sun Ye [Department of Chemical and Materials Engineering, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, KY 40506 (United States); Balk, T. John [Department of Chemical and Materials Engineering, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, KY 40506 (United States)], E-mail: balk@engr.uky.edu

    2008-05-15

    We report a simple two-step dealloying method for producing bulk nanoporous gold with no volume change and no significant cracking. The galvanostatic dealloying method used here appears superior to potentiostatic methods for fabricating millimeter-scale samples. Care must be taken when imaging the nanoscale, interconnected sponge-like structure with a focused ion beam, as even brief exposure caused immediate and extensive cracking of nanoporous gold, as well as ligament coarsening at the surface00.

  7. CENTRIFUGAL VIBRATION TEST OF RC PILE FOUNDATION

    Science.gov (United States)

    Higuchi, Shunichi; Tsutsumiuchi, Takahiro; Otsuka, Rinna; Ito, Koji; Ejiri, Joji

    It is necessary that nonlinear responses of structures are clarified by soil-structure interaction analysis for the purpose of evaluating the seismic performances of underground structure or foundation structure. In this research, centrifuge shake table tests of reinforced concrete pile foundation installed in the liquefied ground were conducted. Then, finite element analyses for the tests were conducted to confirm an applicability of the analytical method by comparing the experimental results and analytical results.

  8. The ratio of right ventricular volume to left ventricular volume reflects the impact of pulmonary regurgitation independently of the method of pulmonary regurgitation quantification

    Energy Technology Data Exchange (ETDEWEB)

    Śpiewak, Mateusz, E-mail: mspiewak@ikard.pl [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Małek, Łukasz A., E-mail: lmalek@ikard.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Interventional Cardiology and Angiology, Institute of Cardiology, Warsaw (Poland); Petryka, Joanna, E-mail: joannapetryka@hotmail.com [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Mazurkiewicz, Łukasz, E-mail: lmazurkiewicz@ikard.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiomyopathy, Institute of Cardiology, Warsaw (Poland); Miłosz, Barbara, E-mail: barbara-milosz@o2.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Biernacka, Elżbieta K., E-mail: kbiernacka@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw (Poland); Kowalski, Mirosław, E-mail: mkowalski@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw (Poland); Hoffman, Piotr, E-mail: phoffman@ikard.pl [Department of Congenital Heart Diseases, Institute of Cardiology, Warsaw (Poland); Demkow, Marcin, E-mail: mdemkow@ikard.pl [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Miśko, Jolanta, E-mail: jmisko@wp.pl [Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Rużyłło, Witold, E-mail: wruzyllo@ikard.pl [Institute of Cardiology, Warsaw (Poland)

    2012-10-15

    Background: Previous studies have advocated quantifying pulmonary regurgitation (PR) by using PR volume (PRV) instead of commonly used PR fraction (PRF). However, physicians are not familiar with the use of PRV in clinical practice. The ratio of right ventricle (RV) volume to left ventricle volume (RV/LV) may better reflect the impact of PR on the heart than RV end-diastolic volume (RVEDV) alone. We aimed to compare the impact of PRV and PRF on RV size expressed as either the RV/LV ratio or RVEDV (mL/m{sup 2}). Methods: Consecutive patients with repaired tetralogy of Fallot were included (n = 53). PRV, PRF and ventricular volumes were measured with the use of cardiac magnetic resonance. Results: RVEDV was more closely correlated with PRV when compared with PRF (r = 0.686, p < 0.0001, and r = 0.430, p = 0.0014, respectively). On the other hand, both PRV and PRF showed a good correlation with the RV/LV ratio (r = 0.691, p < 0.0001, and r = 0.685, p < 0.0001, respectively). Receiver operating characteristic analysis showed that both measures of PR had similar ability to predict severe RV dilatation when the RV/LV ratio-based criterion was used, namely the RV/LV ratio > 2.0 [area under the curve (AUC){sub PRV} = 0.770 vs AUC{sub PRF} = 0.777, p = 0.86]. Conversely, with the use of the RVEDV-based criterion (>170 mL/m{sup 2}), PRV proved to be superior over PRF (AUC{sub PRV} = 0.770 vs AUC{sub PRF} = 0.656, p = 0.0028]. Conclusions: PRV and PRF have similar significance as measures of PR when the RV/LV ratio is used instead of RVEDV. The RV/LV ratio is a universal marker of RV dilatation independent of the method of PR quantification applied (PRF vs PRV)

  9. Netherlands foundation for radioastronomy

    International Nuclear Information System (INIS)

    1979-01-01

    A report of the board is followed by departmental reports from the Westerbork Telescope Group, Dwingeloo Telescope Group, Computer Group, Laboratory and Central Technical Services, Astronomy Group, Administration of the Foundation/General Affairs and Personnel Council. Astronomical reports describe radio astronomical research carried out by the Foundation staff and at the Kapteyn Laboratory Groningen, Leiden Observatory, Utrecht Observatory and the Laboratorio di Radioastronomia Bologna, Italy. Progress in the extension of the synthesis radio telescope and investigations into the possibility of substantially increasing the SRT data rate for solar observations, are outlined. Appendices shows the organisational structure, the names of the employees, the operating budget, the observing facilities at Westerbork and Dwingeloo, and the publications and reports published in 1978 and related to observations made with these facilities. (C.F.)

  10. Antithetic Foundations of Economics

    OpenAIRE

    Marin DINU

    2011-01-01

    This paper aims at decrypting the manner in which the foundations of Economics as a science and the meanings of the relevant explanatory formulas are being shaped. My analytical endeavor focuses on understanding the peculiarities of what is referred to as the object of study of the science known as Economics, an academic synthesis of concept-related breakthroughs regarding economicity. The explicit purpose of this analysis is to identify perennial benchmarks in economic c...

  11. Mathematical foundations of thermodynamics

    CERN Document Server

    Giles, R; Stark, M; Ulam, S

    2013-01-01

    Mathematical Foundations of Thermodynamics details the core concepts of the mathematical principles employed in thermodynamics. The book discusses the topics in a way that physical meanings are assigned to the theoretical terms. The coverage of the text includes the mechanical systems and adiabatic processes; topological considerations; and equilibrium states and potentials. The book also covers Galilean thermodynamics; symmetry in thermodynamics; and special relativistic thermodynamics. The book will be of great interest to practitioners and researchers of disciplines that deal with thermodyn

  12. Topological Foundations of Electromagnetism

    CERN Document Server

    Barrett, Terrence W

    2008-01-01

    Topological Foundations of Electromagnetism seeks a fundamental understanding of the dynamics of electromagnetism; and marshals the evidence that in certain precisely defined topological conditions, electromagnetic theory (Maxwell's theory) must be extended or generalized in order to provide an explanation and understanding of, until now, unusual electromagnetic phenomena. Key to this generalization is an understanding of the circumstances under which the so-called A potential fields have physical effects. Basic to the approach taken is that the topological composition of electromagnetic field

  13. Foundations of image science

    CERN Document Server

    Barrett, Harrison H

    2013-01-01

    Winner of the 2006 Joseph W. Goodman Book Writing Award! A comprehensive treatment of the principles, mathematics, and statistics of image science In today's visually oriented society, images play an important role in conveying messages. From seismic imaging to satellite images to medical images, our modern society would be lost without images to enhance our understanding of our health, our culture, and our world. Foundations of Image Science presents a comprehensive treatment of the principles, mathematics, and st

  14. Foundations for Moral Relativism

    OpenAIRE

    Velleman, J. David

    2015-01-01

    In this new edition of Foundations for Moral Relativism, a distinguished moral philosopher tames a bugbear of current debate about cultural difference. J. David Velleman shows that different communities can indeed be subject to incompatible moralities, because their local mores are rationally binding. At the same time, he explains why the mores of different communities, even when incompatible, are still variations on the same moral themes. The book thus maps out a universe of many moral world...

  15. Foundations of wireless and electronics

    CERN Document Server

    Scroggie, M G

    1984-01-01

    Foundations of Wireless and Electronics, 10th Edition covers the cathode-ray and microwave tubes; modern pulse methods; f.m. detectors; basic processes of transmission; and reception, computers, and non-sinusoidal signal amplification. The book starts by giving a general overview of a complete electronic system, electricity and circuits, capacitance, and inductance. The text also discusses alternating currents (a.c.), including the frequency and phase of a.c.; the capacitance and inductance in a.c. circuits; and the capacitance and inductance in a series. Diodes, triode, transistor equivalent

  16. Foundations of combinatorics with applications

    CERN Document Server

    Bender, Edward A

    2006-01-01

    This introduction to combinatorics, the foundation of the interaction between computer science and mathematics, is suitable for upper-level undergraduates and graduate students in engineering, science, and mathematics.The four-part treatment begins with a section on counting and listing that covers basic counting, functions, decision trees, and sieving methods. The following section addresses fundamental concepts in graph theory and a sampler of graph topics. The third part examines a variety of applications relevant to computer science and mathematics, including induction and recursion, sorti

  17. Wronski's Foundations of Mathematics.

    Science.gov (United States)

    Wagner, Roi

    2016-09-01

    Argument This paper reconstructs Wronski's philosophical foundations of mathematics. It uses his critique of Lagrange's algebraic analysis as a vignette to introduce the problems that he raised, and argues that these problems have not been properly appreciated by his contemporaries and subsequent commentators. The paper goes on to reconstruct Wronski's mathematical law of creation and his notions of theory and techne, in order to put his objections to Lagrange in their philosophical context. Finally, Wronski's proof of his universal law (the expansion of a given function by any series of functions) is reviewed in terms of the above reconstruction. I argue that Wronski's philosophical approach poses an alternative to the views of his contemporary mainstream mathematicians, which brings up the contingency of their choices, and bridges the foundational concerns of early modernity with those of the twentieth-century foundations crisis. I also argue that Wronski's views may be useful to contemporary philosophy of mathematical practice, if they are read against their metaphysical grain.

  18. Systems and methods for the detection of low-level harmful substances in a large volume of fluid

    Science.gov (United States)

    Carpenter, Michael V.; Roybal, Lyle G.; Lindquist, Alan; Gallardo, Vincente

    2016-03-15

    A method and device for the detection of low-level harmful substances in a large volume of fluid comprising using a concentrator system to produce a retentate and analyzing the retentate for the presence of at least one harmful substance. The concentrator system performs a method comprising pumping at least 10 liters of fluid from a sample source through a filter. While pumping, the concentrator system diverts retentate from the filter into a container. The concentrator system also recirculates at least part of the retentate in the container again through the filter. The concentrator system controls the speed of the pump with a control system thereby maintaining a fluid pressure less than 25 psi during the pumping of the fluid; monitors the quantity of retentate within the container with a control system, and maintains a reduced volume level of retentate and a target volume of retentate.

  19. COBRA-SFS [Spent Fuel Storage]: A thermal-hydraulic analysis computer code: Volume 1, Mathematical models and solution method

    International Nuclear Information System (INIS)

    Rector, D.R.; Wheeler, C.L.; Lombardo, N.J.

    1986-11-01

    COBRA-SFS (Spent Fuel Storage) is a general thermal-hydraulic analysis computer code used to predict temperatures and velocities in a wide variety of systems. The code was refined and specialized for spent fuel storage system analyses for the US Department of Energy's Commercial Spent Fuel Management Program. The finite-volume equations governing mass, momentum, and energy conservation are written for an incompressible, single-phase fluid. The flow equations model a wide range of conditions including natural circulation. The energy equations include the effects of solid and fluid conduction, natural convection, and thermal radiation. The COBRA-SFS code is structured to perform both steady-state and transient calculations: however, the transient capability has not yet been validated. This volume describes the finite-volume equations and the method used to solve these equations. It is directed toward the user who is interested in gaining a more complete understanding of these methods

  20. A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

    International Nuclear Information System (INIS)

    Ou, Ming-Ching; Chuang, Ming-Tsung; Lin, Xi-Zhang; Tsai, Hong-Ming; Chen, Shu-Yuan; Liu, Yi-Sheng

    2013-01-01

    Purpose: To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. Materials and methods: A total of 43 liver cirrhosis patients (mean age, 62.19 ± 9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. Results: PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81 ± 1.69 × 10 3 /mm 3 before PSE to 8.56 ± 3.14 × 10 3 /mm 3 at 1 week after PSE (P < 0.001). Mean platelet count significantly increased from 62.00 ± 22.62 × 10 3 /mm 3 before PSE to 95.40 ± 46.29 × 10 3 /mm 3 1 week after PSE (P < 0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearman's rho [ρ] = 0.687, P < 0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16 ± 8.96%. Conclusions: The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearman's ρ = 0.687

  1. Hardy–Weinberg Equilibrium and the Foundations of Evolutionary ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 9. Hardy–Weinberg Equilibrium and the Foundations of Evolutionary Genetics - The Dance of the Genes. Amitabh Joshi. Series Article Volume 13 Issue 9 September 2008 pp 812-835 ...

  2. Hardy–Weinberg Equilibrium and the Foundations of Evolutionary ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 2. Hardy–Weinberg Equilibrium and the Foundations of Evolutionary Genetics - Incorporating Mutation and Migration. Amitabh Joshi. Series Article Volume 16 Issue 2 February 2011 pp 116-128 ...

  3. Three dimensional periodic foundations for base seismic isolation

    International Nuclear Information System (INIS)

    Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

    2015-01-01

    Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

  4. Use of reinforced soil foundation (RSF) to support shallow foundation.

    Science.gov (United States)

    2008-11-01

    The main objective of this research study is to investigate potential benefits of using the reinforced soil foundations to improve the bearing capacity and to reduce the settlement of shallow foundations on soils. This includes examining influences o...

  5. Thermodynamic foundations of applications of ab initio methods for determination of the adsorbate equilibria: hydrogen at the GaN(0001) surface.

    Science.gov (United States)

    Kempisty, Pawel; Strąk, Paweł; Sakowski, Konrad; Kangawa, Yoshihiro; Krukowski, Stanisław

    2017-11-08

    Thermodynamic foundations of ab initio modeling of vapor-solid and vapor-surface equilibria are introduced. The chemical potential change is divided into enthalpy and entropy terms. The enthalpy path passes through vapor-solid transition at zero temperature. The entropy path avoids the singular point at zero temperature passing a solid-vapor transition under normal conditions, where evaporation entropy is employed. In addition, the thermal changes are calculated. The chemical potential difference contribution of the following terms: vaporization enthalpy, vaporization entropy, the temperature-entropy related change, the thermal enthalpy change and mechanical pressure is obtained. The latter term is negligibly small for the pressure typical for epitaxy. The thermal enthalpy change is two orders smaller than the first three terms which have to be taken into account explicitly. The configurational vaporization entropy change is derived for adsorption processes. The same formulation is derived for vapor-surface equilibria using hydrogen at the GaN(0001) surface as an example. The critical factor is the dependence of the enthalpy of evaporation (desorption energy) on the pinning of the Fermi level bringing a drastic change of the value from 2.24 eV to -2.38 eV. In addition it is shown that entropic contributions considerable change the hydrogen equilibrium pressure over the GaN(0001) surface by several orders of magnitude. Thus a complete and exact formulation of vapor-solid and vapor-surface equilibria is presented.

  6. An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions

    NARCIS (Netherlands)

    Hummelink, S.L.; Verhulst, A.C.; Maal, T.J.J.; Hoogeveen, Y.L.; Schultze Kool, L.J.; Ulrich, D.J.O.

    2017-01-01

    BACKGROUND: Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available

  7. A simple method for the production of large volume 3D macroporous hydrogels for advanced biotechnological, medical and environmental applications

    Science.gov (United States)

    Savina, Irina N.; Ingavle, Ganesh C.; Cundy, Andrew B.; Mikhalovsky, Sergey V.

    2016-02-01

    The development of bulk, three-dimensional (3D), macroporous polymers with high permeability, large surface area and large volume is highly desirable for a range of applications in the biomedical, biotechnological and environmental areas. The experimental techniques currently used are limited to the production of small size and volume cryogel material. In this work we propose a novel, versatile, simple and reproducible method for the synthesis of large volume porous polymer hydrogels by cryogelation. By controlling the freezing process of the reagent/polymer solution, large-scale 3D macroporous gels with wide interconnected pores (up to 200 μm in diameter) and large accessible surface area have been synthesized. For the first time, macroporous gels (of up to 400 ml bulk volume) with controlled porous structure were manufactured, with potential for scale up to much larger gel dimensions. This method can be used for production of novel 3D multi-component macroporous composite materials with a uniform distribution of embedded particles. The proposed method provides better control of freezing conditions and thus overcomes existing drawbacks limiting production of large gel-based devices and matrices. The proposed method could serve as a new design concept for functional 3D macroporous gels and composites preparation for biomedical, biotechnological and environmental applications.

  8. A consistent method for finite volume discretization of body forces on collocated grids applied to flow through an actuator disk

    DEFF Research Database (Denmark)

    Troldborg, Niels; Sørensen, Niels N.; Réthoré, Pierre-Elouan

    2015-01-01

    This paper describes a consistent algorithm for eliminating the numerical wiggles appearing when solving the finite volume discretized Navier-Stokes equations with discrete body forces in a collocated grid arrangement. The proposed method is a modification of the Rhie-Chow algorithm where the for...

  9. A superlinearly convergent finite volume method for the incompressible Navier-Stokes equations on staggered unstructured grids

    International Nuclear Information System (INIS)

    Vidovic, D.; Segal, A.; Wesseling, P.

    2004-01-01

    A method for linear reconstruction of staggered vector fields with special treatment of the divergence is presented. An upwind-biased finite volume scheme for solving the unsteady incompressible Navier-Stokes equations on staggered unstructured triangular grids that uses this reconstruction is described. The scheme is applied to three benchmark problems and is found to be superlinearly convergent in space

  10. Impact loads on beams on elastic foundations

    International Nuclear Information System (INIS)

    Kameswara Rao, N.S.V.; Prasad, B.B.

    1975-01-01

    Quite often, complex structural components are idealised as beams in engineering analysis and design. Also, equations governing the responses of shallow shells are mathematically equivalent to the equations governing the responses of beams on elastic foundations. Hence with possible applications in several technical disciplines, the behaviour of beams on elastic foundations subjected to impact loads is studied in detail in the present investigation both analytically and experimentally. The analytical methods include analysis and energy method. The effect of foundation parameters (stiffness, and damping constants) on the dynamic responses of the beam-foundation system has been analysed. In modal analysis, the free-vibration equation has been solved by replacing the applied impulse by suitable initial conditions and the solution has been obtained as the linear combination of an infinite sequence of discrete eigen-vectors. In the energy method, the beam-foundation system is treated to be under forced vibrations and the forcing function has been obtained using the Hertz's law of impact. In the case of free-free end conditions of the beam, the rigid body modes and the elastic modes have been superposed to obtain the total response. The responses predicted using modal analysis are higher than those obtained using energy method. From the present study it is observed that model analysis is preferable to energy method. (Auth.)

  11. Gray-Matter Volume Estimate Score: A Novel Semi-Automatic Method Measuring Early Ischemic Change on CT

    OpenAIRE

    Song, Dongbeom; Lee, Kijeong; Kim, Eun Hye; Kim, Young Dae; Lee, Hye Sun; Kim, Jinkwon; Song, Tae-Jin; Ahn, Sung Soo; Nam, Hyo Suk; Heo, Ji Hoe

    2015-01-01

    Background and Purpose We developed a novel method named Gray-matter Volume Estimate Score (GRAVES), measuring early ischemic changes on Computed Tomography (CT) semi-automatically by computer software. This study aimed to compare GRAVES and Alberta Stroke Program Early CT Score (ASPECTS) with regards to outcome prediction and inter-rater agreement. Methods This was a retrospective cohort study. Among consecutive patients with ischemic stroke in the anterior circulation who received intra-art...

  12. Electrical method for the measurements of volume averaged electron density and effective coupled power to the plasma bulk

    Science.gov (United States)

    Henault, M.; Wattieaux, G.; Lecas, T.; Renouard, J. P.; Boufendi, L.

    2016-02-01

    Nanoparticles growing or injected in a low pressure cold plasma generated by a radiofrequency capacitively coupled capacitive discharge induce strong modifications in the electrical parameters of both plasma and discharge. In this paper, a non-intrusive method, based on the measurement of the plasma impedance, is used to determine the volume averaged electron density and effective coupled power to the plasma bulk. Good agreements are found when the results are compared to those given by other well-known and established methods.

  13. Determination of disintegration rates of a 60Co point source and volume sources by the sum-peak method

    International Nuclear Information System (INIS)

    Kawano, Takao; Ebihara, Hiroshi

    1990-01-01

    The disintegration rates of 60 Co as a point source (<2 mm in diameter on a thin plastic disc) and volume sources (10-100 mL solutions in a polyethylene bottle) are determined by the sum-peak method. The sum-peak formula gives the exact disintegration rate for the point source at different positions from the detector. However, increasing the volume of the solution results in enlarged deviations from the true disintegration rate. Extended sources must be treated as an amalgam of many point sources. (author)

  14. Static Behaviour of Bucket Foundations

    DEFF Research Database (Denmark)

    Larsen, Kim André

    One new foundation concept in relation to offshore wind turbines is bucket foundations. The concept is known from the oil and gas industry, though the load conditions here are significantly different. The bucket foundation can be used as monopod or e.g. tripod foundations for offshore wind turbines....... The monopod concept is investigated in this thesis, regarding the static behaviour from loads relevant to offshore wind turbines. The main issue in this concept is the rotational stiffness of the foundation and the combined capacity dominated by moments. The vertical bearing capacity of bucket foundations...... theory is proposed. The proposed expression applies to plane strain as well as axis-symmetric stress conditions for foundations with smooth or rough bases. A thorough experimental investigation of the static behaviour of bucket foundations subjected to combined loading is carried out. Laboratory tests...

  15. Unknown foundation determination for scour.

    Science.gov (United States)

    2012-04-01

    Unknown foundations affect about 9,000 bridges in Texas. For bridges over rivers, this creates a problem : regarding scour decisions as the calculated scour depth cannot be compared to the foundation depth, and a : very conservative costly approach m...

  16. Wave Forces on Windturbine Foundations

    DEFF Research Database (Denmark)

    Larsen, Brian Juul; Frigaard, Peter

    A testprogramme has been performed to determine the wave forces on two types of foundations for an offshore windturbine. the tested foundation types are a monopile and cone. Furthermore the shaft of the cone has been tested....

  17. AAA Foundation for Traffic Safety

    Science.gov (United States)

    ... of Top Deadly Mistakes Made by Teen Drivers -- AAA AAA: Road debris causes avoidable crashes, deaths Save the ... and 500 deaths! Foundation News Stay Tuned New AAA Foundation for Traffic Safety website coming Fall 2017 ...

  18. A mixed Fourier–Galerkin–finite-volume method to solve the fluid dynamics equations in cylindrical geometries

    International Nuclear Information System (INIS)

    Núñez, Jóse; Ramos, Eduardo; Lopez, Juan M

    2012-01-01

    We describe a hybrid method based on the combined use of the Fourier Galerkin and finite-volume techniques to solve the fluid dynamics equations in cylindrical geometries. A Fourier expansion is used in the angular direction, partially translating the problem to the Fourier space and then solving the resulting equations using a finite-volume technique. We also describe an algorithm required to solve the coupled mass and momentum conservation equations similar to a pressure-correction SIMPLE method that is adapted for the present formulation. Using the Fourier–Galerkin method for the azimuthal direction has two advantages. Firstly, it has a high-order approximation of the partial derivatives in the angular direction, and secondly, it naturally satisfies the azimuthal periodic boundary conditions. Also, using the finite-volume method in the r and z directions allows one to handle boundary conditions with discontinuities in those directions. It is important to remark that with this method, the resulting linear system of equations are band-diagonal, leading to fast and efficient solvers. The benefits of the mixed method are illustrated with example problems. (paper)

  19. Foundation helps refurbish buildings

    International Nuclear Information System (INIS)

    Camenzind, B.

    2006-01-01

    This article looks at the activities of the Swiss 'Climate-Cent' foundation, which is helping support the energetic refurbishment of building envelopes. The conditions which have to be fulfilled to receive grants are explained. Work supported includes the replacement of windows and the insulation of roofs and attics as well as outside walls. Details on the financial support provided and examples of projects supported are given. The source of the finance needed to provide such support - a voluntary levy on petrol - and further support provided in certain Swiss cantons is commented on

  20. Mathematical foundations of elasticity

    CERN Document Server

    Marsden, Jerrold E

    1994-01-01

    This advanced-level study approaches mathematical foundations of three-dimensional elasticity using modern differential geometry and functional analysis. It is directed to mathematicians, engineers and physicists who wish to see this classical subject in a modern setting with examples of newer mathematical contributions. Prerequisites include a solid background in advanced calculus and the basics of geometry and functional analysis.The first two chapters cover the background geometry ― developed as needed ― and use this discussion to obtain the basic results on kinematics and dynamics of con

  1. Web services foundations

    CERN Document Server

    Bouguettaya, Athman; Daniel, Florian

    2013-01-01

    Web services and Service-Oriented Computing (SOC) have become thriving areas of academic research, joint university/industry research projects, and novel IT products on the market. SOC is the computing paradigm that uses Web services as building blocks for the engineering of composite, distributed applications out of the reusable application logic encapsulated by Web services. Web services could be considered the best-known and most standardized technology in use today for distributed computing over the Internet.Web Services Foundations is the first installment of a two-book collection coverin

  2. Instant Zurb Foundation 4

    CERN Document Server

    Arévalo, Jorge

    2013-01-01

    A quick and easy guide that follows a practical approach to rapidly create responsive web pages using Foundation 4 framework, following the mobile-first philosophy.If you are a web developer who wants to get the most out of your HTML5/CSS/JavaScript skills, this book is ideal for you. It is assumed that you will have some experience with these languages, but for those who don't, you can also be up and running in an instant.

  3. Free vibrations and buckling analysis of carbon nanotube-reinforced composite Timoshenko beams on elastic foundation

    International Nuclear Information System (INIS)

    Yas, M.H.; Samadi, N.

    2012-01-01

    This study deals with free vibrations and buckling analysis of nanocomposite Timoshenko beams reinforced by single-walled carbon nanotubes (SWCNTs) resting on an elastic foundation. The SWCNTs are assumed to be aligned and straight with a uniform layout. Four different carbon nanotubes (CNTs) distributions including uniform and three types of functionally graded distributions of CNTs through the thickness are considered. The rule of mixture is used to describe the effective material properties of the nanocomposite beams. The governing equations are derived through using Hamilton's principle and then solved by using the generalized differential quadrature method (GDQM). Natural frequencies and critical buckling load are obtained for nanocomposite beams with different boundary conditions. Effects of several parameters, such as nanotube volume fraction, foundation stiffness parameters, slenderness ratios, CNTs distribution and boundary conditions on both natural frequency and critical buckling load are investigated. The results indicate that the above-mentioned parameters play a very important role on the free vibrations and buckling characteristics of the beam. Highlights: ► Beams with FG-X distribution have highest fundamental frequency. ► Beams with FG-X distribution have highest critical buckling load. ► Using elastic foundation, lead to increase the natural frequency. ► Using elastic foundation, lead to increase the critical buckling load. ► Increasing CNT volume fraction, lead to increase the natural frequency.

  4. Volume reduction of low-level contaminated metal waste by melting: selection of method and conceptual plan

    International Nuclear Information System (INIS)

    Copeland, G.L.; Heestand, R.L.; Mateer, R.S.

    1978-06-01

    A review of the literature and prior experience led to selection of induction melting as the most promising method for volume reduction of low-level transuranic contaminated metal waste. The literature indicates that melting with the appropriate slags significantly lowers the total contamination level of the metals by preferentially concentrating contaminants in the smaller volume of slag. Surface contamination not removed to the slag is diluted in the ingot and is contained uniformly in the metal. This dilution and decontamination offers the potential of lower cost disposal such as shallow burial rather than placement in a national repository. A processing plan is proposed as a model for economic analysis of the collection and volume reduction of contaminated metals. Further development is required to demonstrate feasibility of the plan

  5. Volume-weighted particle-tracking method for solute-transport modeling; Implementation in MODFLOW–GWT

    Science.gov (United States)

    Winston, Richard B.; Konikow, Leonard F.; Hornberger, George Z.

    2018-02-16

    In the traditional method of characteristics for groundwater solute-transport models, advective transport is represented by moving particles that track concentration. This approach can lead to global mass-balance problems because in models of aquifers having complex boundary conditions and heterogeneous properties, particles can originate in cells having different pore volumes and (or) be introduced (or removed) at cells representing fluid sources (or sinks) of varying strengths. Use of volume-weighted particles means that each particle tracks solute mass. In source or sink cells, the changes in particle weights will match the volume of water added or removed through external fluxes. This enables the new method to conserve mass in source or sink cells as well as globally. This approach also leads to potential efficiencies by allowing the number of particles per cell to vary spatially—using more particles where concentration gradients are high and fewer where gradients are low. The approach also eliminates the need for the model user to have to distinguish between “weak” and “strong” fluid source (or sink) cells. The new model determines whether solute mass added by fluid sources in a cell should be represented by (1) new particles having weights representing appropriate fractions of the volume of water added by the source, or (2) distributing the solute mass added over all particles already in the source cell. The first option is more appropriate for the condition of a strong source; the latter option is more appropriate for a weak source. At sinks, decisions whether or not to remove a particle are replaced by a reduction in particle weight in proportion to the volume of water removed. A number of test cases demonstrate that the new method works well and conserves mass. The method is incorporated into a new version of the U.S. Geological Survey’s MODFLOW–GWT solute-transport model.

  6. Problem solving in foundation engineering using foundationPro

    CERN Document Server

    Yamin, Mohammad

    2016-01-01

    This book is at once a supplement to traditional foundation engineering textbooks and an independent problem-solving learning tool. The book is written primarily for university students majoring in civil or construction engineering taking foundation analysis and design courses to encourage them to solve design problems. Its main aim is to stimulate problem solving capability and foster self-directed learning. It also explains the use of the foundationPro software, available at no cost, and includes a set of foundation engineering applications. Taking a unique approach, Dr. Yamin summarizes the general step-by-step procedure to solve various foundation engineering problems, illustrates traditional applications of these steps with longhand solutions, and presents the foundationPro solutions. The special structure of the book allows it to be used in undergraduate and graduate foundation design and analysis courses in civil and construction engineering. The book stands as valuable resource for students, faculty, ...

  7. Shifting Sands, Firm Foundations: Proceedings of the 2009 Annual International Conference of the Association of Tertiary Learning Advisors of Aotearoa/New Zealand (ATLAANZ) (Auckland, New Zealand, November 18-20, 2009). Volume 5

    Science.gov (United States)

    van der Ham, Vanessa, Ed.; Sevillano, Lilia, Ed.; George, Lily, Ed.

    2010-01-01

    The 15 articles in this volume comprise the refereed proceedings of the 2009 ATLAANZ (Association of Tertiary Learning Advisors Aotearoa/New Zealand) conference. The first three chapters focus on collaborative work. In Chapter 1, Ann Pocock shares her experiences of working with other university support services. In Chapter 2, Berni Cooper and…

  8. Cobalt as a gastric juice volume marker: Comparison of two methods of estimation

    International Nuclear Information System (INIS)

    Gana, T.J.; MacPherson, B.R.; Ng, D.; Koo, J.

    1990-01-01

    We investigated the use of cobalt-EDTA, a novel, nonabsorbable liquid phase marker, in the estimation of secretory volumes during topical misoprostol (synthetic PGE, analog) administration in the canine chambered gastric segment. We compared atomic absorption spectrophotometry (AAS) and instrumental neutron activation analysis (INAA) in the estimation of [Co]. Mucosal bathing solutions containing cobalt-EDTA were instilled into and recovered from the chamber by gravity every 15-min period as follows: (i) basal--60 min; (ii) misoprostol periods--150 min (plus 0.1-, 1-, 10-, 100-, and 1000-micrograms doses of misoprostol for two periods per dose). The recovered solutions were analyzed for [Co] by AAS and INAA. Total cobalt recovery by AAS after chamber washout was 102.97 +/- 0.98%. Mean +/- SE volumes (12.14 +/- 0.33 and 13.24 +/- 0.60 ml/15 min) obtained respectively from AAS and INAA were significantly higher (P less than 0.001) than the recovered mean volumes (10.51 +/- 0.17 ml/15 min). The percentage error in volume collection increased (range: 9.3-52.7%) with the volume of secretion. Values of [Co] obtained by the two techniques were comparable and not significantly different from each other (P greater than 0.05). INAA-estimated mean +/- SE [Co] showed consistently higher coefficients of variation. Spectra obtained for all samples during INAA measurements showed significant Compton background activity from 24Na and 38Cl. Cobalt-EDTA did not grossly or histologically damage the gastric mucosa. We conclude that cobalt is not adsorbed, absorbed, or metabolized, and is a suitable and reliable volume marker in this model

  9. On results of measurement and method of behavior analysis for land slide protection wall in excavation works for main building foundation of No.2 plant in Kashiwazaki-Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc

    International Nuclear Information System (INIS)

    Otsuki, Hideo; Tsuchi, Hiroyuki; Nishioka, Toshimichi

    1987-01-01

    Tokyo Electric Power Co. has been constructing the nuclear power station having 8 million kW capacity of seven BWR plants in the site of about 4.2 million m 2 in Niigata Prefecture. No.1 BWR plant of 1100 MWe output started the operation in September, 1985. As a rule, the important structures in nuclear power stations such as a reactor building and a turbine building are to be directly supported on bedrocks, and in this case, on the mudstone of Nishiyama strata. As this Nishiyama strata exists in large depth, the excavation works for the foundations of buildings are to be carried out by installing large scale land slide protection walls. In this report, among the excavation works for the main building foundation of No.2 plant, the results of examining the behavior of the land slide protection wall installed in soft rock ground based on the results of measurement of vertical excavation by land slide protection method and the techniques of its analysis are described. The geological features, the design of land slide protection walls, the measurement of the land slide protection walls and surrounding ground and the results, and the examination of the analysis methods by a beam model and FEM are reported. (Kako, I.)

  10. Disposable photonic integrated circuits for evanescent wave sensors by ultra-high volume roll-to-roll method.

    Science.gov (United States)

    Aikio, Sanna; Hiltunen, Jussi; Hiitola-Keinänen, Johanna; Hiltunen, Marianne; Kontturi, Ville; Siitonen, Samuli; Puustinen, Jarkko; Karioja, Pentti

    2016-02-08

    Flexible photonic integrated circuit technology is an emerging field expanding the usage possibilities of photonics, particularly in sensor applications, by enabling the realization of conformable devices and introduction of new alternative production methods. Here, we demonstrate that disposable polymeric photonic integrated circuit devices can be produced in lengths of hundreds of meters by ultra-high volume roll-to-roll methods on a flexible carrier. Attenuation properties of hundreds of individual devices were measured confirming that waveguides with good and repeatable performance were fabricated. We also demonstrate the applicability of the devices for the evanescent wave sensing of ambient refractive index. The production of integrated photonic devices using ultra-high volume fabrication, in a similar manner as paper is produced, may inherently expand methods of manufacturing low-cost disposable photonic integrated circuits for a wide range of sensor applications.

  11. Monte Carlo Finite Volume Element Methods for the Convection-Diffusion Equation with a Random Diffusion Coefficient

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2014-01-01

    Full Text Available The paper presents a framework for the construction of Monte Carlo finite volume element method (MCFVEM for the convection-diffusion equation with a random diffusion coefficient, which is described as a random field. We first approximate the continuous stochastic field by a finite number of random variables via the Karhunen-Loève expansion and transform the initial stochastic problem into a deterministic one with a parameter in high dimensions. Then we generate independent identically distributed approximations of the solution by sampling the coefficient of the equation and employing finite volume element variational formulation. Finally the Monte Carlo (MC method is used to compute corresponding sample averages. Statistic error is estimated analytically and experimentally. A quasi-Monte Carlo (QMC technique with Sobol sequences is also used to accelerate convergence, and experiments indicate that it can improve the efficiency of the Monte Carlo method.

  12. Comparison of Two Methods for Noninvasive Determination of Stroke Volume During Orthostatic Challenge

    Science.gov (United States)

    Doerr, Donald F.; Ratliff, Duane A.; Sithole, Joseph; Convertino, Victor A.

    2005-01-01

    Background: The real time, beat-by-beat, non-invasive determination of stroke volume (SV) is an important parameter in many aerospace related physiologic protocols. In this study, we compared simultaneous estimates of SV calculated from peripheral pulse waveforms with a more conventional non-invasive technique. Methods: Using a prospective, randomized blinded protocol, ten males and nine females completed 12-mm tilt table protocols. The relative change (%(Delta)) in beat-to-beat SV was estimated non-invasively from changes in pulse waveforms measured by application of infrared finger photoplethysmography (IFP) with a Portapres(Registered TradeMark) blood pressure monitoring device and by thoracic impedance cardiography (TIC). The %(Delta) SV values were calculated from continuous SV measurements in the supine posture and over the first 10 s (T1), second 10 s (T2), and 3.5 minutes (T3) of 80deg head-up tilt (HUT). Results: The average %(Delta) SV measured by IFP at T1 (-11.7 +/- 3.7 %) was statistically less (P measured by TIC at T1 (-21.7 +/- 3.1 %), while the average %(Delta) SV measured by 1FF at T2 (-16.2 +/- 3.9 %) and T3 (-19.1 +/- 3.8 %) were not statistically distinguishable (P > or = 0.322) than the average %(Delta) SV measured by TIC at T2 (-21.8 +/- 2.5 %), and T3 (-22.6 +/- 2.9 %). Correlation coefficients (r(sup 2)) between IFP and TIC were 0.117 (T1), 0.387 (T2), and 0.7 18 (T3). Conclusion: IFP provides beat-to-beat (real time) assessment of %(Delta) SV after 20 sec of transition to an orthostatic challenge that is comparable to the commonly accepted TIC. Our data support the notion that IFP technology which has flown during space missions can be used to accurately assess physiological status and countermeasure effectiveness for orth static problems that may arise in astronauts after space flight. While the peripherally measured IFP response is slightly delayed, the ease of implementing this monitor in the field is advantageous.

  13. Teaching of foundations of radiochemistry on chemical faculty of Moscow State University after M.V. Lomonosov. Methodical ensuring of the subject

    International Nuclear Information System (INIS)

    Luk'yanov, V.B.; Berdonosov, S.S.; Fedoseev, V.M.

    1995-01-01

    The peculiarities of the lecture course on radiochemistry principles in the Moscow State University after M.V. Lomonosov are considered. The methodical provision of the lectures including the curriculum, methodical aids, tasks for self-control and for lecture control, as well as, summary questionary forms, is discussed. 3 refs

  14. Usefulness of acoustic quantification method in left ventricular volume and ejection fraction. Compared with ventriculography and scintigraphy

    International Nuclear Information System (INIS)

    Shibata, Takahiro; Honda, Youichi; Kashiwagi, Hidehiko

    1996-01-01

    Acoustic quantification method (AQ: on-line automated boundary detection system) has proved to have a good correlation with left ventriculography (LVG) and scintigraphy (SG) in patients with normal left ventricular (LV) function. The aim of this study is to determine whether AQ is also useful in patients with abnormal LV function. We examined 54 patients with LV asynergy. End-diastolic volumes with AQ, LVG and SG were 77, 135, 118 ml. A good correlation was found between AQ and LVG and SG (LVG; r=0.81, SG; r=0.68). End-systolic volumes with AQ, LVG and SG were 38, 64 and 57 ml. Left ventricular volumes obtained from AQ had a good correlation with LVG and SG, but were underestimated. LV ejection fraction obtained from AQ had good correlation with those with LVG and SG (LVG; r=0.84. SG; r=0.77). On-line AQ appears to be a useful noninvasive method for evaluation of the left ventricular ejection fraction, but care must be exercised when estimations of left ventricular volumes are made. (author)

  15. Adaptive plasticity model for bucket foundations

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Barari, Amin; Larsen, Kim A.

    2014-01-01

    Based on experimental investigations, the literature proposes different methods for modeling the behavior and capacity of foundations subjected to combined loading. Generally, two methods are used to predict the behavior of foundations: traditional approaches and hardening plasticity solutions......, potential, and failure surfaces are found to be dependent on the embedment ratio (i.e., ratio of skirt length to the diameter) and load path. For the models tested, associated flow is observed to be plausible in the radial planes, whereas nonassociated flow is observed in the planes along the V-axis....

  16. Advances in the discrete ordinates and finite volume methods for the solution of radiative heat transfer problems in participating media

    International Nuclear Information System (INIS)

    Coelho, Pedro J.

    2014-01-01

    Many methods are available for the solution of radiative heat transfer problems in participating media. Among these, the discrete ordinates method (DOM) and the finite volume method (FVM) are among the most widely used ones. They provide a good compromise between accuracy and computational requirements, and they are relatively easy to integrate in CFD codes. This paper surveys recent advances on these numerical methods. Developments concerning the grid structure (e.g., new formulations for axisymmetrical geometries, body-fitted structured and unstructured meshes, embedded boundaries, multi-block grids, local grid refinement), the spatial discretization scheme, and the angular discretization scheme are described. Progress related to the solution accuracy, solution algorithm, alternative formulations, such as the modified DOM and FVM, even-parity formulation, discrete-ordinates interpolation method and method of lines, and parallelization strategies is addressed. The application to non-gray media, variable refractive index media, and transient problems is also reviewed. - Highlights: • We survey recent advances in the discrete ordinates and finite volume methods. • Developments in spatial and angular discretization schemes are described. • Progress in solution algorithms and parallelization methods is reviewed. • Advances in the transient solution of the radiative transfer equation are appraised. • Non-gray media and variable refractive index media are briefly addressed

  17. Gross tumor volume dependency on phase sorting methods of four-dimensional computed tomography images for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Yong; Lim, Sang Wook; Ma, Sun Young; Yu, Je Sang [Dept. of Radiation Oncology, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan (Korea, Republic of)

    2017-09-15

    To see the gross tumor volume (GTV) dependency according to the phase selection and reconstruction methods, we measured and analyzed the changes of tumor volume and motion at each phase in 20 cases with lung cancer patients who underwent image-guided radiotherapy. We retrospectively analyzed four-dimensional computed tomography (4D-CT) images in 20 cases of 19 patients who underwent image-guided radiotherapy. The 4D-CT images were reconstructed by the maximum intensity projection (MIP) and the minimum intensity projection (Min-IP) method after sorting phase as 40%–60%, 30%–70%, and 0%–90%. We analyzed the relationship between the range of motion and the change of GTV according to the reconstruction method. The motion ranges of GTVs are statistically significant only for the tumor motion in craniocaudal direction. The discrepancies of GTV volume and motion between MIP and Min-IP increased rapidly as the wider ranges of duty cycles are selected. As narrow as possible duty cycle such as 40%–60% and MIP reconstruction was suitable for lung cancer if the respiration was stable. Selecting the reconstruction methods and duty cycle is important for small size and for large motion range tumors.

  18. Dual-mixed finite elements for the three-field Stokes model as a finite volume method on staggered grids

    KAUST Repository

    Kou, Jisheng

    2017-06-09

    In this paper, a new three-field weak formulation for Stokes problems is developed, and from this, a dual-mixed finite element method is proposed on a rectangular mesh. In the proposed mixed methods, the components of stress tensor are approximated by piecewise constant functions or Q1 functions, while the velocity and pressure are discretized by the lowest-order Raviart-Thomas element and the piecewise constant functions, respectively. Using quadrature rules, we demonstrate that this scheme can be reduced into a finite volume method on staggered grid, which is extensively used in computational fluid mechanics and engineering.

  19. Adaptive radiotherapy in muscle invasive urinary bladder cancer - An effective method to reduce the irradiated bowel volume

    International Nuclear Information System (INIS)

    Tuomikoski, Laura; Collan, Juhani; Keyrilaeinen, Jani; Visapaeae, Harri; Saarilahti, Kauko; Tenhunen, Mikko

    2011-01-01

    Background and purpose: To evaluate the benefits of adaptive radiotherapy for bladder cancer in decreasing irradiation of small bowel. Material and methods: Five patients with muscle invasive bladder cancer received adaptive radiotherapy to a total dose of 55.8-65 Gy with daily cone-beam computed tomography scanning. The whole bladder was treated to 45-50.4 Gy, followed by a partial bladder boost. The plan of the day was chosen from 3 to 4 pre-planned treatment plans according to the visible extent of bladder wall in cone-beam computed tomography images. Dose volume histograms for intestinal cavity volumes were constructed and compared with corresponding histograms calculated for conventional non-adaptive radiotherapy with single treatment plan of 2 cm CTV-PTV margins. CTV dose coverage in adaptive treatment technique was compared with CTV dose coverage in conventional radiotherapy. Results: The average volume of intestinal cavity receiving ≥45 Gy was reduced from 335 ± 106 cm 3 to 180 ± 113 cm 3 (1SD). The maximum volume of intestinal cavity spared at 45 Gy on a single patient was 240 cm 3 , while the minimum volume was 65 cm 3 . The corresponding reduction in average intestinal cavity volume receiving ≥45 Gy calculated for the whole bladder treatment only was 66 ± 36 cm 3 . CTV dose coverage was improved on two out of five patients and decreased on three patients. Conclusions: Adaptive radiotherapy considerably reduces dose to the small bowel, while maintaining the dose coverage of CTV at similar level when compared to the conventional treatment technique.

  20. Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    1979-01-01

    The last day of March 1978 marked the completion of the first 3 years of operation of the Radiation Effects Research Foundation in Hiroshima and Nagasaki. RERF was established on 1 April 1975 as successor to the Atomic Bomb Casualty Commission which had been in continuous operation since 1947. This record of the first 3 years of operation consists of selected reports and other documents prepared in the course of conducting the business of RERF and includes a brief history, a late radiation effects that might be conducted at RERF. The wisdom and thought given to the research program and its operation by the Scientific Council and the Board of Directors is reflected in the minutes of their meetings which are included in the Appendix. (Mori, K.)

  1. Foundations of quantum gravity

    CERN Document Server

    Lindesay, James

    2013-01-01

    Exploring how the subtleties of quantum coherence can be consistently incorporated into Einstein’s theory of gravitation, this book is ideal for researchers interested in the foundations of relativity and quantum physics. The book examines those properties of coherent gravitating systems that are most closely connected to experimental observations. Examples of consistent co-gravitating quantum systems whose overall effects upon the geometry are independent of the coherence state of each constituent are provided, and the properties of the trapping regions of non-singular black objects, black holes, and a dynamic de Sitter cosmology are discussed analytically, numerically, and diagrammatically. The extensive use of diagrams to summarise the results of the mathematics enables readers to bypass the need for a detailed understanding of the steps involved. Assuming some knowledge of quantum physics and relativity, the book provides textboxes featuring supplementary information for readers particularly interested ...

  2. Foundations of signal processing

    CERN Document Server

    Vetterli, Martin; Goyal, Vivek K

    2014-01-01

    This comprehensive and engaging textbook introduces the basic principles and techniques of signal processing, from the fundamental ideas of signals and systems theory to real-world applications. Students are introduced to the powerful foundations of modern signal processing, including the basic geometry of Hilbert space, the mathematics of Fourier transforms, and essentials of sampling, interpolation, approximation and compression. The authors discuss real-world issues and hurdles to using these tools, and ways of adapting them to overcome problems of finiteness and localisation, the limitations of uncertainty and computational costs. Standard engineering notation is used throughout, making mathematical examples easy for students to follow, understand and apply. It includes over 150 homework problems and over 180 worked examples, specifically designed to test and expand students' understanding of the fundamentals of signal processing, and is accompanied by extensive online materials designed to aid learning, ...

  3. Cálculo do volume na equação de van der Waals pelo método de cardano Volume calculation in van der Waals equation by the cardano method

    Directory of Open Access Journals (Sweden)

    Nelson H. T. Lemes

    2010-01-01

    Full Text Available Analytical solutions of a cubic equation with real coefficients are established using the Cardano method. The method is first applied to simple third order equation. Calculation of volume in the van der Waals equation of state is afterwards established. These results are exemplified to calculate the volumes below and above critical temperatures. Analytical and numerical values for the compressibility factor are presented as a function of the pressure. As a final example, coexistence volumes in the liquid-vapor equilibrium are calculated. The Cardano approach is very simple to apply, requiring only elementary operations, indicating an attractive method to be used in teaching elementary thermodynamics.

  4. Assessment of the ABC/2 Method of Epidural Hematoma Volume Measurement as Compared to Computer-Assisted Planimetric Analysis.

    Science.gov (United States)

    Hu, Ting-Ting; Yan, Ling; Yan, Peng-Fei; Wang, Xuan; Yue, Ge-Fen

    2016-01-01

    Epidural hematoma volume (EDHV) is an independent predictor of prognosis in patients with epidural hematoma (EDH) and plays a central role in treatment decision making. This study's objective was to determine the accuracy and reliability of the widely used volume measurement method ABC/2 in estimating EDHV by comparing it to the computer-assisted planimetric method. A data set of computerized tomography (CT) scans of 35 patients with EDH was evaluated to determine the accuracy of ABC/2 method, using computer-assisted planimetric technique to establish the reference criterion of EDHV for each patient. Another data set was constructed by randomly selecting 5 patients then replicating each case twice to yield 15 patients. Intra- and interobserver reliability were evaluated by asking four observers to independently estimate EDHV for the latter data set using the ABC/2 method. Estimation of EDHV using the ABC/2 method showed high intra- and interobserver reliability (intra-class correlation coefficient = .99). These estimates were closely correlated with planimetric measures (r = .99). But the ABC/2 method generally overestimated EDHV, especially in the nonellipsoid-like group. The difference between the ABC/2 measures and planimetric measures was statistically significant (p ABC/2 method could be used for EDHV measurement, which would contribute to treatment decision making as well as clinical outcome prediction. However, clinicians should be aware that the ABC/2 method results in a general volume overestimation. Future studies focusing on justification of the technique to improve its accuracy would be of practical value. © The Author(s) 2015.

  5. Mathematical foundation of geodesy selected papers of Torben Krarup

    CERN Document Server

    Borre, K

    2006-01-01

    This volume contains selected papers by Torben Krarup, one of the most important geodesists of the 20th century. The collection includes the famous booklet "A Contribution to the Mathematical Foundation of Physical Geodesy" from 1969, the unpublished "Molodenskij letters" from 1973, the final version of "Integrated Geodesy" from 1978, "Foundation of a Theory of Elasticity for Geodetic Networks" from 1974, as well as trend-setting papers on the theory of adjustment.

  6. RELAP5/MOD3 code manual: Code structure, system models, and solution methods. Volume 1

    International Nuclear Information System (INIS)

    1995-08-01

    The RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents, and operational transients, such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling, approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I provides modeling theory and associated numerical schemes

  7. ATHENA code manual. Volume 1. Code structure, system models, and solution methods

    International Nuclear Information System (INIS)

    Carlson, K.E.; Roth, P.A.; Ransom, V.H.

    1986-09-01

    The ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) code has been developed to perform transient simulation of the thermal hydraulic systems which may be found in fusion reactors, space reactors, and other advanced systems. A generic modeling approach is utilized which permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of a complete facility. Several working fluids are available to be used in one or more interacting loops. Different loops may have different fluids with thermal connections between loops. The modeling theory and associated numerical schemes are documented in Volume I in order to acquaint the user with the modeling base and thus aid effective use of the code. The second volume contains detailed instructions for input data preparation

  8. Neutron and synchrotron radiation for condensed matter studies. Volume 1: theory, instruments and methods

    International Nuclear Information System (INIS)

    Baruchel, J.; Hodeau, J.L.; Lehmann, M.S.; Regnard, J.R.; Schlenker, C.

    1993-01-01

    This book provides the basic information required by a research scientist wishing to undertake studies using neutrons or synchrotron radiation at a Large Facility. These lecture notes result from 'HERCULES', a course that has been held in Grenoble since 1991 to train young scientists in these fields. They cover the production of neutrons and synchrotron radiation and describe all aspects of instrumentation. In addition, this work outlines the basics of the various fields of research pursued at these Large Facilities. It consists of a series of chapters written by experts in the particular fields. While following a progression and constituting a lecture course on neutron and x-ray scattering, these chapters can also be read independently. This first volume will be followed by two further volumes concerned with the applications to solid state physics and chemistry, and to biology and soft condensed matter properties

  9. A novel method for the angiographic estimation of the percentage of spleen volume embolized during partial splenic embolization

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Ming-Ching; Chuang, Ming-Tsung [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Lin, Xi-Zhang [Department of Internal Medicine, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Tsai, Hong-Ming; Chen, Shu-Yuan [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China); Liu, Yi-Sheng, E-mail: taicheng100704@yahoo.com.tw [Department of Diagnostic Radiology, National Cheng-Kung University Hospital, No. 138 Sheng Li Road, Tainan 704, Taiwan, ROC (China)

    2013-08-15

    Purpose: To evaluate the efficacy of estimating the volume of spleen embolized in partial splenic embolization (PSE) by measuring the diameters of the splenic artery and its branches. Materials and methods: A total of 43 liver cirrhosis patients (mean age, 62.19 ± 9.65 years) with thrombocytopenia were included. Among these, 24 patients underwent a follow-up CT scan which showed a correlation between angiographic estimation and measured embolized splenic volume. Estimated splenic embolization volume was calculated by a method based on diameters of the splenic artery and its branches. The diameters of each of the splenic arteries and branches were measured via 2D angiographic images. Embolization was performed with gelatin sponges. Patients underwent follow-up with serial measurement of blood counts and liver function tests. The actual volume of embolized spleen was determined by computed tomography (CT) measuring the volumes of embolized and non-embolized spleen two months after PSE. Results: PSE was performed without immediate major complications. The mean WBC count significantly increased from 3.81 ± 1.69 × 10{sup 3}/mm{sup 3} before PSE to 8.56 ± 3.14 × 10{sup 3}/mm{sup 3} at 1 week after PSE (P < 0.001). Mean platelet count significantly increased from 62.00 ± 22.62 × 10{sup 3}/mm{sup 3} before PSE to 95.40 ± 46.29 × 10{sup 3}/mm{sup 3} 1 week after PSE (P < 0.001). The measured embolization ratio was positively correlated with estimated embolization ratio (Spearman's rho [ρ] = 0.687, P < 0.001). The mean difference between the actual embolization ratio and the estimated embolization ratio was 16.16 ± 8.96%. Conclusions: The method provides a simple method to quantitatively estimate embolized splenic volume with a correlation of measured embolization ratio to estimated embolization ratio of Spearman's ρ = 0.687.

  10. Novel reprocessing methods with nuclide separation for volume reduction of high level radioactive waste

    International Nuclear Information System (INIS)

    Suzuki, Tatsuya

    2015-01-01

    We have proposed the reprocessing system with nuclide separation processes based on the chromatographic technique in the hydrochloric acid solution system. Our proposing system consists of the dissolution process, the reprocessing process, the MA separation process, and nuclide separation processes. In our proposing processes, the pyridine resin is used as a main separation media. We expect that our proposing will contribute to that volume reduction of high level radioactive waste by combining the transmutation techniques, usage of valuable elements, and so on. (author)

  11. Preliminary analytical study on the feasibility of using reinforced concrete pile foundations for renewable energy storage by compressed air energy storage technology

    Science.gov (United States)

    Tulebekova, S.; Saliyev, D.; Zhang, D.; Kim, J. R.; Karabay, A.; Turlybek, A.; Kazybayeva, L.

    2017-11-01

    Compressed air energy storage technology is one of the promising methods that have high reliability, economic feasibility and low environmental impact. Current applications of the technology are mainly limited to energy storage for power plants using large scale underground caverns. This paper explores the possibility of making use of reinforced concrete pile foundations to store renewable energy generated from solar panels or windmills attached to building structures. The energy will be stored inside the pile foundation with hollow sections via compressed air. Given the relatively small volume of storage provided by the foundation, the required storage pressure is expected to be higher than that in the large-scale underground cavern. The high air pressure typically associated with large temperature increase, combined with structural loads, will make the pile foundation in a complicated loading condition, which might cause issues in the structural and geotechnical safety. This paper presents a preliminary analytical study on the performance of the pile foundation subjected to high pressure, large temperature increase and structural loads. Finite element analyses on pile foundation models, which are built from selected prototype structures, have been conducted. The analytical study identifies maximum stresses in the concrete of the pile foundation under combined pressure, temperature change and structural loads. Recommendations have been made for the use of reinforced concrete pile foundations for renewable energy storage.

  12. Development of volume reduction method of cesium contaminated soil with magnetic separation

    International Nuclear Information System (INIS)

    Yukumatsu, Kazuki; Nomura, Naoki; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro

    2016-01-01

    In this study, we developed a new volume reduction technique for cesium contaminated soil by magnetic separation. Cs in soil is mainly adsorbed on clay which is the smallest particle constituent in the soil, especially on paramagnetic 2:1 type clay minerals which strongly adsorb and fix Cs. Thus selective separation of 2:1 type clay with a superconducting magnet could enable to reduce the volume of Cs contaminated soil. The 2:1 type clay particles exist in various particle sizes in the soil, which leads that magnetic force and Cs adsorption quantity depend on their particle size. Accordingly, we examined magnetic separation conditions for efficient separation of 2:1 type clay considering their particle size distribution. First, the separation rate of 2:1 type clay for each particle size was calculated by particle trajectory simulation, because magnetic separation rate largely depends on the objective size. According to the calculation, 73 and 89 % of 2:1 type clay could be separated at 2 and 7 T, respectively. Moreover we calculated dose reduction rate on the basis of the result of particle trajectory simulation. It was indicated that 17 and 51 % of dose reduction would be possible at 2 and 7 T, respectively. The difference of dose reduction rate at 2 T and 7 T was found to be separated a fine particle. It was shown that magnetic separation considering particle size distribution would contribute to the volume reduction of contaminated soil

  13. The method of estimating the irradiated lung volume in primary breast irradiation

    International Nuclear Information System (INIS)

    Leite, Miguel Torres Teixeira; Marques, Iara Silva; Geraldo, Jony Marques

    1999-01-01

    Tangential breast fields irradiation usually includes some volume of lung and it is occasionally associated with pneumonitis. The estimation of the amount of lung irradiated can be determined measuring the central lung distance (CLD) by the port films, and it must be inferior to 2.5 cm. The purpose of this study was to determine through a linear regression analysis the relationship between CLD and the geometrical parameters of the treatment, and to develop an equation to predict this volume. The studied population consisted of 100 patients who received definitive radiation for clinical stage I and II breast cancer between January, 1996 and June, 1997. According to the contour of the breast and thorax was determined the angle of the tangential fields. In 71% of the patients the CLD measured by the portal films were superior to 2.5 cm, requiring a new beam arrangement. We develop a simple and convenient quantitative model to predict the irradiated lung volume based on portal films. We need further analysis in order to include variables and antomical variations. (author)

  14. A new graphic method for evaluation of distribution volume on N-isopropyl-p-[123I]iodoamphetamine (IMP) SPECT

    International Nuclear Information System (INIS)

    Odano, Ikuo; Takahashi, Naoya; Ohtaki, Hiroh; Noguchi, Eikichi; Hatano, Masayoshi; Yamasaki, Yoshihiro; Nishihara, Mamiko; Ohkubo, Masaki; Yokoi, Takashi.

    1993-01-01

    We developed a new graphic method using N-isopropyl-p-[ 123 I]iodoamphetamine (IMP) and SPECT of the brain, the graph on which all three parameters, cerebral blood flow, distribution volume (V d ) and delayed count to early count ratio (Delayed/Early ratio), were able to be evaluated simultaneously. The kinetics of 123 I-IMP in the brain was analyzed by a 2-compartment model, and a standard input function was prepared by averaging the time activity curves of 123 I-IMP in arterial blood on 6 patients with small cerebral infarction etc. including 2 normal controls. Being applied this method to the differential diagnosis between Parkinson's disease and progressive supranuclear palsy, we were able to differentiate both with a glance, because the distribution volume of the frontal lobe significantly decreased in Parkinson's disease (Mean±SD; 26±6 ml/g). This method was clinically useful. We think that the distribution volume of 123 I-IMP may reflect its retention mechanism in the brain, and the values are related to amine, especially to dopamine receptors and its metabolism. (author)

  15. A combined volume-of-fluid method and low-Mach-number approach for DNS of evaporating droplets in turbulence

    Science.gov (United States)

    Dodd, Michael; Ferrante, Antonino

    2017-11-01

    Our objective is to perform DNS of finite-size droplets that are evaporating in isotropic turbulence. This requires fully resolving the process of momentum, heat, and mass transfer between the droplets and surrounding gas. We developed a combined volume-of-fluid (VOF) method and low-Mach-number approach to simulate this flow. The two main novelties of the method are: (i) the VOF algorithm captures the motion of the liquid gas interface in the presence of mass transfer due to evaporation and condensation without requiring a projection step for the liquid velocity, and (ii) the low-Mach-number approach allows for local volume changes caused by phase change while the total volume of the liquid-gas system is constant. The method is verified against an analytical solution for a Stefan flow problem, and the D2 law is verified for a single droplet in quiescent gas. We also demonstrate the schemes robustness when performing DNS of an evaporating droplet in forced isotropic turbulence.

  16. Cardiac chamber volumes by echocardiography using a new mathematical method: A promising technique for zero-G use

    Science.gov (United States)

    Buckey, J. C.; Beattie, J. M.; Gaffney, F. A.; Nixon, J. V.; Blomqvist, C. G.

    1984-01-01

    Accurate, reproducible, and non-invasive means for ventricular volume determination are needed for evaluating cardiovascular function zero-gravity. Current echocardiographic methods, particularly for the right ventricle, suffer from a large standard error. A new mathematical approach, recently described by Watanabe et al., was tested on 1 normal formalin-fixed human hearts suspended in a mineral oil bath. Volumes are estimated from multiple two-dimensional echocardiographic views recorded from a single point at sequential angles. The product of sectional cavity area and center of mass for each view summed over the range of angles (using a trapezoidal rule) gives volume. Multiple (8-14) short axis right ventricle and left ventricle views at 5.0 deg intervals were videotaped. The images were digitized by two independent observers (leading-edge to leading-edge technique) and analyzed using a graphics tablet and microcomputer. Actual volumes were determined by filling the chambers with water. These data were compared to the mean of the two echo measurements.

  17. An ancillary method in urine cytology: Nucleolar/nuclear volume ratio for discrimination between benign and malignant urothelial cells.

    Science.gov (United States)

    Tone, Kiyoshi; Kojima, Keiko; Hoshiai, Keita; Kumagai, Naoya; Kijima, Hiroshi; Kurose, Akira

    2016-06-01

    The essential of urine cytology for the diagnosis and the follow-up of urothelial neoplasia has been widely recognized. However, there are some cases in which a definitive diagnosis cannot be made due to difficulty in discriminating between benign and malignant. This study evaluated the practicality of nucleolar/nuclear volume ratio (%) for the discrimination. Using Papanicolaou-stained slides, 253 benign urothelial cells and 282 malignant urothelial cells were selected and divided into a benign urothelial cell and an urothelial carcinoma (UC) cell groups. Three suspicious cases and four cases in which discrimination between benign and malignant was difficult were prepared for verification test. Subject cells were decolorized and stained with 4',6-diamidino-2-phenylindole for detection of the nuclei and the nucleoli. Z-stack method was performed to analyze. When the cutoff point of 1.514% discriminating benign urothelial cells and UC cells from nucleolar/nuclear volume ratio (%) was utilized, the sensitivity was 56.0%, the specificity was 88.5%, the positive predictive value was 84.5%, and the negative predictive value was 64.4%. Nuclear and nucleolar volume, number of the nucleoli, and nucleolar/nuclear volume ratio (%) were significantly higher in the UC cell group than in the benign urothelial cell group (P benign and malignant urothelial cells, providing possible additional information in urine cytology. Diagn. Cytopathol. 2016;44:483-491. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  18. Effect of solution volume covariation on the growth mechanism of Au nanorods using the seed-mediated method

    International Nuclear Information System (INIS)

    Ma, Xiao; Wang, Moo-Chin; Feng, Jinyang; Zhao, Xiujian

    2015-01-01

    The effect of solution volume covariation on the growth mechanism of Au nanorods synthesized using a seed-mediated method was studied. The results from the ultraviolet–visible absorption spectra of gold nanorods (GNRs) revealed that the transverse surface plasmon resonance was ∼550 nm for all GNR samples synthesized in various total volumes of growth solutions. The wavelength of longitudinal surface plasmon resonance of GNRs increased from 757 to 915 nm, with the total volume of growth solution being raised from 10 to 320 ml. Moreover, the calculated aspect ratio (AR) also increased from 3.55 to 5.21 while the total volume of growth solution increased from 10 to 320 ml. Transmission electron microscopy microstructures showed that the growth mechanism of GNRs along 〈1 0 0〉 is in accordance with the hypothesis that the ratio of the number of monodispersed Au atoms existing in the growth solution to the number of seeds explain the behavior of Au atoms deposited on the nanorods with respect to all of the constituent concentrations in the growth solution on the AR of GNRs

  19. Fluence map optimization (FMO) with dose–volume constraints in IMRT using the geometric distance sorting method

    International Nuclear Information System (INIS)

    Lan Yihua; Li Cunhua; Ren Haozheng; Zhang Yong; Min Zhifang

    2012-01-01

    A new heuristic algorithm based on the so-called geometric distance sorting technique is proposed for solving the fluence map optimization with dose–volume constraints which is one of the most essential tasks for inverse planning in IMRT. The framework of the proposed method is basically an iterative process which begins with a simple linear constrained quadratic optimization model without considering any dose–volume constraints, and then the dose constraints for the voxels violating the dose–volume constraints are gradually added into the quadratic optimization model step by step until all the dose–volume constraints are satisfied. In each iteration step, an interior point method is adopted to solve each new linear constrained quadratic programming. For choosing the proper candidate voxels for the current dose constraint adding, a so-called geometric distance defined in the transformed standard quadratic form of the fluence map optimization model was used to guide the selection of the voxels. The new geometric distance sorting technique can mostly reduce the unexpected increase of the objective function value caused inevitably by the constraint adding. It can be regarded as an upgrading to the traditional dose sorting technique. The geometry explanation for the proposed method is also given and a proposition is proved to support our heuristic idea. In addition, a smart constraint adding/deleting strategy is designed to ensure a stable iteration convergence. The new algorithm is tested on four cases including head–neck, a prostate, a lung and an oropharyngeal, and compared with the algorithm based on the traditional dose sorting technique. Experimental results showed that the proposed method is more suitable for guiding the selection of new constraints than the traditional dose sorting method, especially for the cases whose target regions are in non-convex shapes. It is a more efficient optimization technique to some extent for choosing constraints than

  20. Fluence map optimization (FMO) with dose-volume constraints in IMRT using the geometric distance sorting method.

    Science.gov (United States)

    Lan, Yihua; Li, Cunhua; Ren, Haozheng; Zhang, Yong; Min, Zhifang

    2012-10-21

    A new heuristic algorithm based on the so-called geometric distance sorting technique is proposed for solving the fluence map optimization with dose-volume constraints which is one of the most essential tasks for inverse planning in IMRT. The framework of the proposed method is basically an iterative process which begins with a simple linear constrained quadratic optimization model without considering any dose-volume constraints, and then the dose constraints for the voxels violating the dose-volume constraints are gradually added into the quadratic optimization model step by step until all the dose-volume constraints are satisfied. In each iteration step, an interior point method is adopted to solve each new linear constrained quadratic programming. For choosing the proper candidate voxels for the current dose constraint adding, a so-called geometric distance defined in the transformed standard quadratic form of the fluence map optimization model was used to guide the selection of the voxels. The new geometric distance sorting technique can mostly reduce the unexpected increase of the objective function value caused inevitably by the constraint adding. It can be regarded as an upgrading to the traditional dose sorting technique. The geometry explanation for the proposed method is also given and a proposition is proved to support our heuristic idea. In addition, a smart constraint adding/deleting strategy is designed to ensure a stable iteration convergence. The new algorithm is tested on four cases including head-neck, a prostate, a lung and an oropharyngeal, and compared with the algorithm based on the traditional dose sorting technique. Experimental results showed that the proposed method is more suitable for guiding the selection of new constraints than the traditional dose sorting method, especially for the cases whose target regions are in non-convex shapes. It is a more efficient optimization technique to some extent for choosing constraints than the dose

  1. Development of a unified sizing method for gas radiation heating facilities used in large-volume buildings; Developpement d'une methode de dimensionnement unifiee d'installations de chauffage radiant gaz pour les batiments de grand volume

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, M.; Bego, L.; Douls, Y.; Le Dean, P.; Paradowski, V. [Gaz de France, GDF, Dir. de la Recherche, 75 - Paris (France)

    2000-07-01

    Builders now have perfect command of the natural gas heating technique used for large-volume buildings. However, the sizing of heating facilities still leaves grounds for discussion, whatever the energies actually used. Accordingly, between 1997 and 1999, the ATG (technical association of the Gas industry in France), seven French manufacturers of 'large volume' heating equipment, the Chaleur Et Rayonnement (CER) association and Gaz de France decided to collaborate and develop a 'unified sizing method' for heating facilities using radiating emitters. During the first year of the study, the above partners worked on the said method (theoretical thermal study of the radiative phenomena, and then adaptation to the methods currently used by the various manufacturers). In 1998, with the support of the ADEME (the French environment and energy control agency), the partners tested the method on five industrial buildings (studying the thermal behavior and making air renewal measurements with search gases). This work made it possible to either confirm or adapt the theoretical evaluations which had been made originally. In 1999, a software program was produced to make the developed method more user friendly. The program can be used to determine the power to be installed, but also to assess the quality of the chosen configuration of the emitters (unit power, inclination, orientation) for optimum customer comfort. (authors)

  2. An inverse analysis of a transient 2-D conduction-radiation problem using the lattice Boltzmann method and the finite volume method coupled with the genetic algorithm

    International Nuclear Information System (INIS)

    Das, Ranjan; Mishra, Subhash C.; Ajith, M.; Uppaluri, R.

    2008-01-01

    This article deals with the simultaneous estimation of parameters in a 2-D transient conduction-radiation heat transfer problem. The homogeneous medium is assumed to be absorbing, emitting and scattering. The boundaries of the enclosure are diffuse gray. Three parameters, viz. the scattering albedo, the conduction-radiation parameter and the boundary emissivity, are simultaneously estimated by the inverse method involving the lattice Boltzmann method (LBM) and the finite volume method (FVM) in conjunction with the genetic algorithm (GA). In the direct method, the FVM is used for computing the radiative information while the LBM is used to solve the energy equation. The temperature field obtained in the direct method is used in the inverse method for simultaneous estimation of unknown parameters using the LBM-FVM and the GA. The LBM-FVM-GA combination has been found to accurately predict the unknown parameters

  3. Evaluation of the reconstruction method and effect of partial volume in brain scintiscanning; Avaliacao do metodo de reconstrucao e efeito do volume parcial em cintilografia cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Monica Araujo

    2016-10-01

    Alzheimer's disease is a neurodegenerative disorder, on which occurs a progressive and irreversible destruction of neurons. According to the World Health Organization (WHO) 35.6 million people are living with dementia, being recommended that governments prioritize early diagnosis techniques. Laboratory and psychological tests for cognitive assessment are conducted and further complemented by neurological imaging from nuclear medicine exams in order to establish an accurate diagnosis. The image quality evaluation and reconstruction process effects are important tools in clinical routine. In the present work, these quality parameters were studied, and the effects of partial volume (PVE) for lesions of different sizes and geometries that are attributed to the limited resolution of the equipment. In dementia diagnosis, this effect can be confused with intake losses due to cerebral cortex atrophy. The evaluation was conducted by two phantoms of different shapes as suggested by (a) American College of Radiology (ACR) and (b) National Electrical Manufacturers Association (NEMA) for Contrast, Contrast-to-Noise Ratio (CNR) and Recovery Coefficient (RC) calculation versus lesions shape and size. Technetium-99m radionuclide was used in a local brain scintigraphy protocol, for proportions lesion to background of 2:1, 4:1, 6:1, 8:1 and 10:1. Fourteen reconstruction methods were used for each concentration applying different filters and algorithms. Before the analysis of all image properties, the conclusion is that the predominant effect is the partial volume, leading to errors of measurement of more than 80%. Furthermore, it was demonstrate that the most effective method of reconstruction is FBP with Metz filter, providing better contrast and contrast to noise ratio results. In addition, this method shows the best Recovery Coefficients correction for each lesion. The ACR phantom showed the best results assigned to a more precise reconstruction of a cylinder, which does not

  4. Coupling of a 3-D vortex particle-mesh method with a finite volume near-wall solver

    Science.gov (United States)

    Marichal, Y.; Lonfils, T.; Duponcheel, M.; Chatelain, P.; Winckelmans, G.

    2011-11-01

    This coupling aims at improving the computational efficiency of high Reynolds number bluff body flow simulations by using two complementary methods and exploiting their respective advantages in distinct parts of the domain. Vortex particle methods are particularly well suited for free vortical flows such as wakes or jets (the computational domain -with non zero vorticity- is then compact and dispersion errors are negligible). Finite volume methods, however, can handle boundary layers much more easily due to anisotropic mesh refinement. In the present approach, the vortex method is used in the whole domain (overlapping domain technique) but its solution is highly underresolved in the vicinity of the wall. It thus has to be corrected by the near-wall finite volume solution at each time step. Conversely, the vortex method provides the outer boundary conditions for the near-wall solver. A parallel multi-resolution vortex particle-mesh approach is used here along with an Immersed Boundary method in order to take the walls into account. The near-wall flow is solved by OpenFOAM® using the PISO algorithm. We validate the methodology on the flow past a sphere at a moderate Reynolds number. F.R.S. - FNRS Research Fellow.

  5. A simple method to retrospectively estimate patient dose-area product for chest tomosynthesis examinations performed using VolumeRAD

    Energy Technology Data Exchange (ETDEWEB)

    Båth, Magnus, E-mail: magnus.bath@vgregion.se; Svalkvist, Angelica [Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg SE-413 45, Sweden and Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg SE-413 45 (Sweden); Söderman, Christina [Department of Radiation Physics, Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg SE-413 45 (Sweden)

    2014-10-15

    Purpose: The purpose of the present work was to develop and validate a method of retrospectively estimating the dose-area product (DAP) of a chest tomosynthesis examination performed using the VolumeRAD system (GE Healthcare, Chalfont St. Giles, UK) from digital imaging and communications in medicine (DICOM) data available in the scout image. Methods: DICOM data were retrieved for 20 patients undergoing chest tomosynthesis using VolumeRAD. Using information about how the exposure parameters for the tomosynthesis examination are determined by the scout image, a correction factor for the adjustment in field size with projection angle was determined. The correction factor was used to estimate the DAP for 20 additional chest tomosynthesis examinations from DICOM data available in the scout images, which was compared with the actual DAP registered for the projection radiographs acquired during the tomosynthesis examination. Results: A field size correction factor of 0.935 was determined. Applying the developed method using this factor, the average difference between the estimated DAP and the actual DAP was 0.2%, with a standard deviation of 0.8%. However, the difference was not normally distributed and the maximum error was only 1.0%. The validity and reliability of the presented method were thus very high. Conclusions: A method to estimate the DAP of a chest tomosynthesis examination performed using the VolumeRAD system from DICOM data in the scout image was developed and validated. As the scout image normally is the only image connected to the tomosynthesis examination stored in the picture archiving and communication system (PACS) containing dose data, the method may be of value for retrospectively estimating patient dose in clinical use of chest tomosynthesis.

  6. Evaluation of diastolic phase by left ventricular volume curve using s2-gated equilibrium method among radioisotope angiography

    International Nuclear Information System (INIS)

    Watanabe, Yoshirou; Sakai, Akira; Inada, Mitsuo; Shiraishi, Tomokuni; Kobayashi, Akitoshi

    1982-01-01

    S2-gated (the second heart sound) method was designed by authors. In 6 normal subjects and 16 patients (old myocardial infarction 12 cases, hypertension 2 cases and aortic regurgitation 2 cases), radioisotope (RI) angiography using S2-gated equilibrium method was performed. In RI angiography, sup(99m)Tc-human serum albumin (HSA) 555MBq (15mCi) as tracer, PDP11/34 as minicomputer and PCG/ECG symchromizer (Metro Inst.) were used. Then left ventricular (LV) volume curve by S2-gated and electrocardiogram (ECG) R wave-gated method were obtained. Using LV volume curve, left ventricular ejection fraction (EF), mean ejection rate (mER, s -1 ), mean filling rate (mFR, -1 ) and rapid filling fraction (RFF) were calculated. mFR indicated mean filling rate during rapid filling phase. RFF was defined as the filling fraction during rapid filling phase among stroke volume. S2-gated method was reliable in evaluation of early diastolic phase, compared with ECG-gated method. There was the difference between RFF in normal group and myocardial infarction (MI) group (p < 0.005). RFF in 2 groups were correlated with EF (r = 0.82, p < 0.01). RFF was useful in evaluating MI cases who had normal EF values. The comparison with mER by ECG-gated and mFR by S2-gated was useful in evaluating MI cases who had normal mER values. mFR was remarkably lower than mER in MI group, but was equal to mER in normal group approximately. In conclusion, the evaluation using RFF and mFR by S2-gated method was useful in MI cases who had normal systolic phase indices. (author)

  7. A simple method to retrospectively estimate patient dose-area product for chest tomosynthesis examinations performed using VolumeRAD

    International Nuclear Information System (INIS)

    Båth, Magnus; Svalkvist, Angelica; Söderman, Christina

    2014-01-01

    Purpose: The purpose of the present work was to develop and validate a method of retrospectively estimating the dose-area product (DAP) of a chest tomosynthesis examination performed using the VolumeRAD system (GE Healthcare, Chalfont St. Giles, UK) from digital imaging and communications in medicine (DICOM) data available in the scout image. Methods: DICOM data were retrieved for 20 patients undergoing chest tomosynthesis using VolumeRAD. Using information about how the exposure parameters for the tomosynthesis examination are determined by the scout image, a correction factor for the adjustment in field size with projection angle was determined. The correction factor was used to estimate the DAP for 20 additional chest tomosynthesis examinations from DICOM data available in the scout images, which was compared with the actual DAP registered for the projection radiographs acquired during the tomosynthesis examination. Results: A field size correction factor of 0.935 was determined. Applying the developed method using this factor, the average difference between the estimated DAP and the actual DAP was 0.2%, with a standard deviation of 0.8%. However, the difference was not normally distributed and the maximum error was only 1.0%. The validity and reliability of the presented method were thus very high. Conclusions: A method to estimate the DAP of a chest tomosynthesis examination performed using the VolumeRAD system from DICOM data in the scout image was developed and validated. As the scout image normally is the only image connected to the tomosynthesis examination stored in the picture archiving and communication system (PACS) containing dose data, the method may be of value for retrospectively estimating patient dose in clinical use of chest tomosynthesis

  8. BEDVH--A method for evaluating biologically effective dose volume histograms: Application to eye plaque brachytherapy implants

    International Nuclear Information System (INIS)

    Gagne, Nolan L.; Leonard, Kara L.; Huber, Kathryn E.; Mignano, John E.; Duker, Jay S.; Laver, Nora V.; Rivard, Mark J.

    2012-01-01

    Purpose: A method is introduced to examine the influence of implant duration T, radionuclide, and radiobiological parameters on the biologically effective dose (BED) throughout the entire volume of regions of interest for episcleral brachytherapy using available radionuclides. This method is employed to evaluate a particular eye plaque brachytherapy implant in a radiobiological context. Methods: A reference eye geometry and 16 mm COMS eye plaque loaded with 103 Pd, 125 I, or 131 Cs sources were examined with dose distributions accounting for plaque heterogeneities. For a standardized 7 day implant, doses to 90% of the tumor volume ( TUMOR D 90 ) and 10% of the organ at risk volumes ( OAR D 10 ) were calculated. The BED equation from Dale and Jones and published α/β and μ parameters were incorporated with dose volume histograms (DVHs) for various T values such as T = 7 days (i.e., TUMOR 7 BED 10 and OAR 7 BED 10 ). By calculating BED throughout the volumes, biologically effective dose volume histograms (BEDVHs) were developed for tumor and OARs. Influence of T, radionuclide choice, and radiobiological parameters on TUMOR BEDVH and OAR BEDVH were examined. The nominal dose was scaled for shorter implants to achieve biological equivalence. Results: TUMOR D 90 values were 102, 112, and 110 Gy for 103 Pd, 125 I, and 131 Cs, respectively. Corresponding TUMOR 7 BED 10 values were 124, 140, and 138 Gy, respectively. As T decreased from 7 to 0.01 days, the isobiologically effective prescription dose decreased by a factor of three. As expected, TUMOR 7 BEDVH did not significantly change as a function of radionuclide half-life but varied by 10% due to radionuclide dose distribution. Variations in reported radiobiological parameters caused TUMOR 7 BED 10 to deviate by up to 46%. Over the range of OAR α/β values, OAR 7 BED 10 varied by up to 41%, 3.1%, and 1.4% for the lens, optic nerve, and lacrimal gland, respectively. Conclusions: BEDVH permits evaluation of the

  9. Method and timing of tumor volume measurement for outcome prediction in cervical cancer using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Mayr, Nina A.; Taoka, Toshiaki; Yuh, William T.C.; Denning, Leah M.; Zhen, Weining K.; Paulino, Arnold C.; Gaston, Robert C.; Sorosky, Joel I.; Meeks, Sanford L.; Walker, Joan L.; Mannel, Robert S.; Buatti, John M.

    2002-01-01

    Purpose: Recently, imaging-based tumor volume before, during, and after radiation therapy (RT) has been shown to predict tumor response in cervical cancer. However, the effectiveness of different methods and timing of imaging-based tumor size assessment have not been investigated. The purpose of this study was to compare the predictive value for treatment outcome derived from simple diameter-based ellipsoid tumor volume measurement using orthogonal diameters (with ellipsoid computation) with that derived from more complex contour tracing/region-of-interest (ROI) analysis 3D tumor volumetry. Methods and Materials: Serial magnetic resonance imaging (MRI) examinations were prospectively performed in 60 patients with advanced cervical cancer (Stages IB 2 -IVB/recurrent) at the start of RT, during early RT (20-25 Gy), mid-RT (45-50 Gy), and at follow-up (1-2 months after RT completion). ROI-based volumetry was derived by tracing the entire tumor region in each MR slice on the computer work station. For the diameter-based surrogate ''ellipsoid volume,'' the three orthogonal diameters (d 1 , d 2 , d 3 ) were measured on film hard copies to calculate volume as an ellipsoid (d 1 x d 2 x d 3 x π/6). Serial tumor volumes and regression rates determined by each method were correlated with local control, disease-free and overall survival, and the results were compared between the two measuring methods. Median post-therapy follow-up was 4.9 years (range, 2.0-8.2 years). Results: The best method and time point of tumor size measurement for the prediction of outcome was the tumor regression rate in the mid-therapy MRI examination (at 45-50 Gy) using 3D ROI volumetry. For the pre-RT measurement both the diameter-based method and ROI volumetry provided similar predictive accuracy, particularly for patients with small ( 3 ) and large (≥100 cm 3 ) pre-RT tumor size. However, the pre-RT tumor size measured by either method had much less predictive value for the intermediate-size (40

  10. Nonlinear soil-structure interaction analysis based on the boundary-element method in time domain with application to embedded foundation

    International Nuclear Information System (INIS)

    Wolf, J.P.; Darbre, G.R.

    1985-01-01

    The computational procedure of the so-called truncated indirect boundary-element method is derived. The latter, which is non-local in space and time, represents a rigorous generally applicable procedure for taking into account a layered halfspace in a non-linear soil-structure interaction analysis. As an example, the non-linear soil-structure interaction analysis of a structure embedded in a halfspace with partial uplift of the basement and separation of the side wall is investigated. (orig.)

  11. A non-invasive method of quantifying pancreatic volume in mice using micro-MRI.

    Directory of Open Access Journals (Sweden)

    Jose L Paredes

    Full Text Available In experimental models of pancreatic growth and recovery, changes in pancreatic size are assessed by euthanizing a large cohort of animals at varying time points and measuring organ mass. However, to ascertain this information in clinical practice, patients with pancreatic disorders routinely undergo non-invasive cross-sectional imaging of the pancreas using magnetic resonance imaging (MRI or computed tomography (CT. The aim of the current study was to develop a thin-sliced, optimized sequence protocol using a high field MRI to accurately calculate pancreatic volumes in the most common experimental animal, the mouse. Using a 7 Telsa Bruker micro-MRI system, we performed abdominal imaging in whole-fixed mice in three standard planes: axial, sagittal, and coronal. The contour of the pancreas was traced using Vitrea software and then transformed into a 3-dimensional (3D reconstruction, from which volumetric measurements were calculated. Images were optimized using heart perfusion-fixation, T1 sequence analysis, and 0.2 to 0.4 mm thick slices. As proof of principle, increases in pancreatic volume among mice of different ages correlated tightly with increasing body weight. In summary, this is the first study to measure pancreatic volumes in mice, using a high field 7 Tesla micro-MRI and a thin-sliced, optimized sequence protocol. We anticipate that micro-MRI will improve the ability to non-invasively quantify changes in pancreatic size and will dramatically reduce the number of animals required to serially assess pancreatic growth and recovery.

  12. Research on the Construction Method of Square Permutation Foundation in Photovoltaic Power Station%光伏电站方阵基础的施工方法探讨

    Institute of Scientific and Technical Information of China (English)

    余祖良; 陈魁

    2013-01-01

      通过太阳能电池方阵将太阳能辐射能转换为电能的发电站称为太阳能光伏电站,太阳能光伏电站按照运行方式可分为独立太阳能光伏电站和并网太阳能光伏电站。文章简述了光伏电站方阵基础的几种施工方法。%Taking solar and radiant energy into electric energy by solar arrays is defined as solar photovoltaic power station. It can be categorized into independent solar photo voltaic power station and grid-combined solar photo voltaic power station in its own way. Several construction methods with square permutation foundation in photovoltaic power station are elaborated.

  13. Foundations of resilience thinking.

    Science.gov (United States)

    Curtin, Charles G; Parker, Jessica P

    2014-08-01

    Through 3 broad and interconnected streams of thought, resilience thinking has influenced the science of ecology and natural resource management by generating new multidisciplinary approaches to environmental problem solving. Resilience science, adaptive management (AM), and ecological policy design (EPD) contributed to an internationally unified paradigm built around the realization that change is inevitable and that science and management must approach the world with this assumption, rather than one of stability. Resilience thinking treats actions as experiments to be learned from, rather than intellectual propositions to be defended or mistakes to be ignored. It asks what is novel and innovative and strives to capture the overall behavior of a system, rather than seeking static, precise outcomes from discrete action steps. Understanding the foundations of resilience thinking is an important building block for developing more holistic and adaptive approaches to conservation. We conducted a comprehensive review of the history of resilience thinking because resilience thinking provides a working context upon which more effective, synergistic, and systems-based conservation action can be taken in light of rapid and unpredictable change. Together, resilience science, AM, and EPD bridge the gaps between systems analysis, ecology, and resource management to provide an interdisciplinary approach to solving wicked problems. © 2014 Society for Conservation Biology.

  14. The logical foundations of mathematics

    CERN Document Server

    Hatcher, William S

    1981-01-01

    The Logical Foundations of Mathematics offers a study of the foundations of mathematics, stressing comparisons between and critical analyses of the major non-constructive foundational systems. The position of constructivism within the spectrum of foundational philosophies is discussed, along with the exact relationship between topos theory and set theory.Comprised of eight chapters, this book begins with an introduction to first-order logic. In particular, two complete systems of axioms and rules for the first-order predicate calculus are given, one for efficiency in proving metatheorems, and

  15. The foundations of modern time series analysis

    CERN Document Server

    Mills, Terence C

    2011-01-01

    This book develops the analysis of Time Series from its formal beginnings in the 1890s through to the publication of Box and Jenkins' watershed publication in 1970, showing how these methods laid the foundations for the modern techniques of Time Series analysis that are in use today.

  16. The need for rotational margins in intensity-modulated radiotherapy and a new method for planning target volume design

    International Nuclear Information System (INIS)

    Langer, Mark Peter; Papiez, Lech; Spirydovich, Siarhei; Thai, Van

    2005-01-01

    Purpose: The effect of rotational errors on the coverage of clinical target volumes (CTVs) is examined. A new planning target volume (PTV) construction that considers the individual paths traced by movements of the target boundary points is developed. Methods and Materials: A standard uniform margin expansion was compared with a PTV constructed from the space swept out by a concave moving target. A new method formed the PTV by aggregating the separate convex hulls taken of the positions of the individual target boundary points in a sampling of CTV displacements. Results: A 0.5-cm uniform margin adequate for translations was inadequate given CTV rotation about a fixed off-center axis. A PTV formed of the target's swept-out area was 22% smaller than needed for coverage by a uniform margin, but computationally is not readily extended to translations combined with rotations about a shifting axis. Forming instead the union of convex hulls of the boundary points in a sampling of CTV displacements represented these movements in the PTV design and retained the target's concave shape. Conclusions: Planning target volumes should accommodate target rotation. The union of convex hulls of the boundary point positions in a sampling of displacements can effectively represent multiple sources of deviations while preserving target concavities

  17. Wobbled splatting-a fast perspective volume rendering method for simulation of x-ray images from CT

    International Nuclear Information System (INIS)

    Birkfellner, Wolfgang; Seemann, Rudolf; Figl, Michael; Hummel, Johann; Ede, Christopher; Homolka, Peter; Yang Xinhui; Niederer, Peter; Bergmann, Helmar

    2005-01-01

    3D/2D registration, the automatic assignment of a global rigid-body transformation matching the coordinate systems of patient and preoperative volume scan using projection images, is an important topic in image-guided therapy and radiation oncology. A crucial part of most 3D/2D registration algorithms is the fast computation of digitally rendered radiographs (DRRs) to be compared iteratively to radiographs or portal images. Since registration is an iterative process, fast generation of DRRs-which are perspective summed voxel renderings-is desired. In this note, we present a simple and rapid method for generation of DRRs based on splat rendering. As opposed to conventional splatting, antialiasing of the resulting images is not achieved by means of computing a discrete point spread function (a so-called footprint), but by stochastic distortion of either the voxel positions in the volume scan or by the simulation of a focal spot of the x-ray tube with non-zero diameter. Our method generates slightly blurred DRRs suitable for registration purposes at framerates of approximately 10 Hz when rendering volume images with a size of 30 MB. (note)

  18. Finite volume method for radiative heat transfer in an unstructured flow solver for emitting, absorbing and scattering media

    International Nuclear Information System (INIS)

    Gazdallah, Moncef; Feldheim, Véronique; Claramunt, Kilian; Hirsch, Charles

    2012-01-01

    This paper presents the implementation of the finite volume method to solve the radiative transfer equation in a commercial code. The particularity of this work is that the method applied on unstructured hexahedral meshes does not need a pre-processing step establishing a particular marching order to visit all the control volumes. The solver simply visits the faces of the control volumes as numbered in the hexahedral unstructured mesh. A cell centred mesh and a spatial differencing step scheme to relate facial radiative intensities to nodal intensities is used. The developed computer code based on FVM has been integrated in the CFD solver FINE/Open from NUMECA Int. Radiative heat transfer can be evaluated within systems containing uniform, grey, emitting, absorbing and/or isotropically or linear anisotropically scattering medium bounded by diffuse grey walls. This code has been validated for three test cases. The first one is a three dimensional rectangular enclosure filled with emitting, absorbing and anisotropically scattering media. The second is the differentially heated cubic cavity. The third one is the L-shaped enclosure. For these three test cases a good agreement has been observed when temperature and heat fluxes predictions are compared with references taken, from literature.

  19. Assessment of rigid multi-modality image registration consistency using the multiple sub-volume registration (MSR) method

    International Nuclear Information System (INIS)

    Ceylan, C; Heide, U A van der; Bol, G H; Lagendijk, J J W; Kotte, A N T J

    2005-01-01

    Registration of different imaging modalities such as CT, MRI, functional MRI (fMRI), positron (PET) and single photon (SPECT) emission tomography is used in many clinical applications. Determining the quality of any automatic registration procedure has been a challenging part because no gold standard is available to evaluate the registration. In this note we present a method, called the 'multiple sub-volume registration' (MSR) method, for assessing the consistency of a rigid registration. This is done by registering sub-images of one data set on the other data set, performing a crude non-rigid registration. By analysing the deviations (local deformations) of the sub-volume registrations from the full registration we get a measure of the consistency of the rigid registration. Registration of 15 data sets which include CT, MR and PET images for brain, head and neck, cervix, prostate and lung was performed utilizing a rigid body registration with normalized mutual information as the similarity measure. The resulting registrations were classified as good or bad by visual inspection. The resulting registrations were also classified using our MSR method. The results of our MSR method agree with the classification obtained from visual inspection for all cases (p < 0.02 based on ANOVA of the good and bad groups). The proposed method is independent of the registration algorithm and similarity measure. It can be used for multi-modality image data sets and different anatomic sites of the patient. (note)

  20. A Three-Dimensional, Immersed Boundary, Finite Volume Method for the Simulation of Incompressible Heat Transfer Flows around Complex Geometries

    Directory of Open Access Journals (Sweden)

    Hassan Badreddine

    2017-01-01

    Full Text Available The current work focuses on the development and application of a new finite volume immersed boundary method (IBM to simulate three-dimensional fluid flows and heat transfer around complex geometries. First, the discretization of the governing equations based on the second-order finite volume method on Cartesian, structured, staggered grid is outlined, followed by the description of modifications which have to be applied to the discretized system once a body is immersed into the grid. To validate the new approach, the heat conduction equation with a source term is solved inside a cavity with an immersed body. The approach is then tested for a natural convection flow in a square cavity with and without circular cylinder for different Rayleigh numbers. The results computed with the present approach compare very well with the benchmark solutions. As a next step in the validation procedure, the method is tested for Direct Numerical Simulation (DNS of a turbulent flow around a surface-mounted matrix of cubes. The results computed with the present method compare very well with Laser Doppler Anemometry (LDA measurements of the same case, showing that the method can be used for scale-resolving simulations of turbulence as well.

  1. Foundations of mathematical analysis

    CERN Document Server

    Johnsonbaugh, Richard

    2010-01-01

    This classroom-tested volume offers a definitive look at modern analysis, with views of applications to statistics, numerical analysis, Fourier series, differential equations, mathematical analysis, and functional analysis. Upper-level undergraduate students with a background in calculus will benefit from its teachings, along with beginning graduate students seeking a firm grounding in modern analysis. A self-contained text, it presents the necessary background on the limit concept, and the first seven chapters could constitute a one-semester introduction to limits. Subsequent chapters discuss

  2. Sudden Arrhythmia Death Syndromes (SADS) Foundation

    Science.gov (United States)

    ... SADS Foundation UK SADS Foundation Netherlands SADS Foundation China SADS Foundation Hong Kong Search for: Log in ... research crucial for health of patients and the economy 7/18/2017 More funding for heart disease ...

  3. Evaluating the philosophical foundation of 2013 Curriculum

    Directory of Open Access Journals (Sweden)

    M. Mardiana

    2017-12-01

    Full Text Available The study was to: (1 identify the interpretation toward the philosophical foundation of 2013 Curriculum; and (2 evaluate the philosophical foundation of 2013 Curriculum. In order to achieve these objectives, the researchers implemented the method of philosophy interpretation, namely a method that might discover an individual’s paradigm through the texts or the articles that he or she composed. Furthermore, in order to evaluate the philosophical foundation of 2013 Curriculum the researchers implemented certain criteria and this effort was supported by the expert interview. The data were analyzed by means of hermeneutic method, namely the presence of a relationship among the three elements namely text, interpreter and reader. The conclusions of the study then were as follows: (1 the interpretation toward the philosophical foundation of 2013 Curriculum contained six points namely: (a establishing and developing the nation’s attitude and civilization or the nation’s character, (b developing the curriculum based on the nation’s culture, (c referring to the fact that education had been a process of developing the learning participants’ potentials, (d referring to the fact that education had been based on the nation’s culture and experience in the past, (e referring to the fact that education had been basis of the nation’s life continuity and (f Referring to the fact that education had been adjusted to the life of the learning participants as an individual, a society member and a citizen; (2 the six philosophical reasons namely: (a perennialism, (b essentialism, (c progressivism, (d pragmatism, (e existentialism and (f reconstructionism; (3 the following evaluation results: (a the philosophical foundation of 2013 Curriculum based on the interpretation results had provided clear educational objectives and functions, (b the philosophical foundation of 2013 Curriculum had been in accordance to facts, (c the philosophical foundation of 2013

  4. Comparison of pathogen DNA isolation methods from large volumes of whole blood to improve molecular diagnosis of bloodstream infections.

    Directory of Open Access Journals (Sweden)

    Anne J M Loonen

    Full Text Available For patients suffering from bloodstream infections (BSI molecular diagnostics from whole blood holds promise to provide fast and adequate treatment. However, this approach is hampered by the need of large blood volumes. Three methods for pathogen DNA isolation from whole blood were compared, i.e. an enzymatic method (MolYsis, 1-5 ml, the novel non-enzymatic procedure (Polaris, 1-5 ml, and a method that does not entail removal of human DNA (Triton-Tris-EDTA EasyMAG, 200 µl. These methods were evaluated by processing blood spiked with 0-1000 CFU/ml of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Downstream detection was performed with real-time PCR assays. Polaris and MolYsis processing followed by real-time PCRs enabled pathogen detection at clinically relevant concentrations of 1-10 CFU/ml blood. By increasing sample volumes, concurrent lower cycle threshold (Ct values were obtained at clinically relevant pathogen concentrations, demonstrating the benefit of using larger blood volumes. A 100% detection rate at a concentration of 10 CFU/ml for all tested pathogens was obtained with the Polaris enrichment, whereas comparatively lower detection rates were measured for MolYsis (50-67% and EasyMAG (58-79%. For the samples with a concentration of 1 CFU/ml Polaris resulted in most optimal detection rates of 70-75% (MolYsis 17-50% and TTE-EasyMAG 20-36%. The Polaris method was more reproducible, less labour intensive, and faster (45 minutes (including Qiagen DNA extraction vs. 2 hours (MolYsis. In conclusion, Polaris and MolYsis enrichment followed by DNA isolation and real-time PCR enables reliable and sensitive detection of bacteria and fungi from 5 ml blood. With Polaris results are available within 3 hours, showing potential for improved BSI diagnostics.

  5. A simple method to retrospectively estimate patient dose-area product for chest tomosynthesis examinations performed using VolumeRAD.

    Science.gov (United States)

    Båth, Magnus; Söderman, Christina; Svalkvist, Angelica

    2014-10-01

    The purpose of the present work was to develop and validate a method of retrospectively estimating the dose-area product (DAP) of a chest tomosynthesis examination performed using the VolumeRAD system (GE Healthcare, Chalfont St. Giles, UK) from digital imaging and communications in medicine (DICOM) data available in the scout image. DICOM data were retrieved for 20 patients undergoing chest tomosynthesis using VolumeRAD. Using information about how the exposure parameters for the tomosynthesis examination are determined by the scout image, a correction factor for the adjustment in field size with projection angle was determined. The correction factor was used to estimate the DAP for 20 additional chest tomosynthesis examinations from DICOM data available in the scout images, which was compared with the actual DAP registered for the projection radiographs acquired during the tomosynthesis examination. A field size correction factor of 0.935 was determined. Applying the developed method using this factor, the average difference between the estimated DAP and the actual DAP was 0.2%, with a standard deviation of 0.8%. However, the difference was not normally distributed and the maximum error was only 1.0%. The validity and reliability of the presented method were thus very high. A method to estimate the DAP of a chest tomosynthesis examination performed using the VolumeRAD system from DICOM data in the scout image was developed and validated. As the scout image normally is the only image connected to the tomosynthesis examination stored in the picture archiving and communication system (PACS) containing dose data, the method may be of value for retrospectively estimating patient dose in clinical use of chest tomosynthesis.

  6. Predicting volume of distribution with decision tree-based regression methods using predicted tissue:plasma partition coefficients.

    Science.gov (United States)

    Freitas, Alex A; Limbu, Kriti; Ghafourian, Taravat

    2015-01-01

    Volume of distribution is an important pharmacokinetic property that indicates the extent of a drug's distribution in the body tissues. This paper addresses the problem of how to estimate the apparent volume of distribution at steady state (Vss) of chemical compounds in the human body using decision tree-based regression methods from the area of data mining (or machine learning). Hence, the pros and cons of several different types of decision tree-based regression methods have been discussed. The regression methods predict Vss using, as predictive features, both the compounds' molecular descriptors and the compounds' tissue:plasma partition coefficients (Kt:p) - often used in physiologically-based pharmacokinetics. Therefore, this work has assessed whether the data mining-based prediction of Vss can be made more accurate by using as input not only the compounds' molecular descriptors but also (a subset of) their predicted Kt:p values. Comparison of the models that used only molecular descriptors, in particular, the Bagging decision tree (mean fold error of 2.33), with those employing predicted Kt:p values in addition to the molecular descriptors, such as the Bagging decision tree using adipose Kt:p (mean fold error of 2.29), indicated that the use of predicted Kt:p values as descriptors may be beneficial for accurate prediction of Vss using decision trees if prior feature selection is applied. Decision tree based models presented in this work have an accuracy that is reasonable and similar to the accuracy of reported Vss inter-species extrapolations in the literature. The estimation of Vss for new compounds in drug discovery will benefit from methods that are able to integrate large and varied sources of data and flexible non-linear data mining methods such as decision trees, which can produce interpretable models. Graphical AbstractDecision trees for the prediction of tissue partition coefficient and volume of distribution of drugs.

  7. Crack Monitoring of Operational Wind Turbine Foundations.

    Science.gov (United States)

    Perry, Marcus; McAlorum, Jack; Fusiek, Grzegorz; Niewczas, Pawel; McKeeman, Iain; Rubert, Tim

    2017-08-21

    The degradation of onshore, reinforced-concrete wind turbine foundations is usually assessed via above-ground inspections, or through lengthy excavation campaigns that suspend wind power generation. Foundation cracks can and do occur below ground level, and while sustained measurements of crack behaviour could be used to quantify the risk of water ingress and reinforcement corrosion, these cracks have not yet been monitored during turbine operation. Here, we outline the design, fabrication and field installation of subterranean fibre-optic sensors for monitoring the opening and lateral displacements of foundation cracks during wind turbine operation. We detail methods for in situ sensor characterisation, verify sensor responses against theoretical tower strains derived from wind speed data, and then show that measured crack displacements correlate with monitored tower strains. Our results show that foundation crack opening displacements respond linearly to tower strain and do not change by more than ±5 μ m. Lateral crack displacements were found to be negligible. We anticipate that the work outlined here will provide a starting point for real-time, long-term and dynamic analyses of crack displacements in future. Our findings could furthermore inform the development of cost-effective monitoring systems for ageing wind turbine foundations.

  8. 1D and 2D Numerical Modeling for Solving Dam-Break Flow Problems Using Finite Volume Method

    Directory of Open Access Journals (Sweden)

    Szu-Hsien Peng

    2012-01-01

    Full Text Available The purpose of this study is to model the flow movement in an idealized dam-break configuration. One-dimensional and two-dimensional motion of a shallow flow over a rigid inclined bed is considered. The resulting shallow water equations are solved by finite volumes using the Roe and HLL schemes. At first, the one-dimensional model is considered in the development process. With conservative finite volume method, splitting is applied to manage the combination of hyperbolic term and source term of the shallow water equation and then to promote 1D to 2D. The simulations are validated by the comparison with flume experiments. Unsteady dam-break flow movement is found to be reasonably well captured by the model. The proposed concept could be further developed to the numerical calculation of non-Newtonian fluid or multilayers fluid flow.

  9. Effect of various methods for rectum delineation on relative and absolute dose-volume histograms for prostate IMRT treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Kusumoto, Chiaki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ohira, Shingo [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita (Japan); Miyazaki, Masayoshi [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Ueda, Yoshihiro [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Department of Radiation Oncology, Graduate School of Medicine, Osaka University, Suita (Japan); Isono, Masaru [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Teshima, Teruki, E-mail: teshima-te@mc.pref.osaka.jp [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan)

    2016-07-01

    Several reports have dealt with correlations of late rectal toxicity with rectal dose-volume histograms (DVHs) for high dose levels. There are 2 techniques to assess rectal volume for reception of a specific dose: relative-DVH (R-DVH, %) that indicates relative volume for a vertical axis, and absolute-DVH (A-DVH, cc) with its vertical axis showing absolute volume of the rectum. The parameters of DVH vary depending on the rectum delineation method, but the literature does not present any standardization of such methods. The aim of the present study was to evaluate the effects of different delineation methods on rectal DVHs. The enrollment for this study comprised 28 patients with high-risk localized prostate cancer, who had undergone intensity-modulated radiation therapy (IMRT) with the prescription dose of 78 Gy. The rectum was contoured with 4 different methods using 2 lengths, short (Sh) and long (Lg), and 2 cross sections, rectum (Rec) and rectal wall (Rw). Sh means the length from 1 cm above the seminal vesicles to 1 cm below the prostate and Lg the length from the rectosigmoid junction to the anus. Rec represents the entire rectal volume including the rectal contents and Rw the rectal volume of the area with a wall thickness of 4 mm. We compared dose-volume parameters by using 4 rectal contour methods for the same plan with the R-DVHs as well as the A-DVHs. For the high dose levels, the R-DVH parameters varied widely. The mean of V{sub 70} for Sh-Rw was the highest (19.4%) and nearly twice as high as that for Lg-Rec (10.4%). On the contrary, only small variations were observed in the A-DVH parameters (4.3, 4.3, 5.5, and 5.5 cc for Sh-Rw, Lg-Rw, Sh-Rec, and Lg-Rec, respectively). As for R-DVHs, the parameters of V{sub 70} varied depending on the rectal lengths (Sh-Rec vs Lg-Rec: R = 0.76; Sh-Rw vs Lg-Rw: R = 0.85) and cross sections (Sh-Rec vs Sh-Rw: R = 0.49; Lg-Rec vs Lg-Rw: R = 0.65). For A-DVHs, however, the parameters of Sh rectal A-DVHs hardly changed

  10. Methods for volume reduction and recycling of LLW arising from decommissioning of nuclear installations

    International Nuclear Information System (INIS)

    Krause, G.; Bergstroem, L.

    2003-01-01

    Radioactive contaminated waste is a great cost factor for nuclear power plants and other nuclear industry. On the deregulated electricity market the price of produced kWh is an important competition tool. Therefore many power producers in the process to achieve savings and hence low production costs have given waste minimization and volume reduction highest priority. Studsvik RadWaste AB in Nykoeping, Sweden, is successfully providing incineration and scrap metal treatment services for customers from Europe, Japan and the USA. Since 1987 thousands of tonnes of metal have been released for unrestricted re-use and recycling in commercial steel industry. The incineration service, provided since 1976, results in 97% volume reduction and generates biologically inert ash suitable for disposal in a final radioactive waste repository. Both processes, which are quality and environmentally certified, reduce the cost of interim storage and disposal. In addition, the companies within the Studsvik Group offer a wide range of services such as transportation, measurement and safeguard, site assistance, industrial cleaning and decontamination in connection with demolition on site. (authors)

  11. Al- Khwarizmi and axiomatic foundation of algebra

    International Nuclear Information System (INIS)

    Fares, N.

    2015-01-01

    This paper intends to investigate the axiomatic foundations of algebra, as they were presented in the book of algebra of al-Khwarizmi (9 th century), and as they were developed in many subsequent Arabic works. The paper gives also a description of algebra evolution towards a discipline independent ofgeometry and arithmetic: the two disciplines whosemarriage had led to its birth.By an in depth reading of some details in the text of al Khwarizmi , we concluded that this mathematician intended to lay down the axiomatic foundations of that new discipline. His resort to arithmetical and geometrical means was a way of making his theory more accessible. He used them to justify the axioms: those that were not explicitly introduced per se, and those that were remained implicit. The paper also relies on some unedited writingsof al-Khwarizmi's successors, which could shedlight on the ways they used to consolidate the foundations of algebra and improve its methods. (author)

  12. Comparison of six methods of segmentation of tumor volume on the 18F-F.D.G. PET scan with reference histological volume in non small cell bronchopulmonary cancers

    International Nuclear Information System (INIS)

    Venel, Y.; Garhi, H.; Baulieu, J.L.; Prunier-Aesch, C.; Muret, A. de; Barillot, I.

    2008-01-01

    The 18 F-F.D.G. PET has demonstrated its importance in oncology, for initial extension and efficacy of anti tumoral therapeutics. Several studies have attempted to prove its utility to define tumoral volumes for conformational radiotherapy in non small cell lung cancers. Some authors have suggested the use of threshold of tumor intensity uptake with 40 or 50% of maximal intensity. Black et al. have determined contouring with linear regression formula of mean semi-quantitative index of tumor uptake (standard uptake value): SUV threshold = 0.307 Sub average + 0.588. Nestle et al. have taken into account the background noise intensity and mean intensity of the tumor: I threshold = β I average +I noise with β 0.15. Our study was done in collaboration with Inserm U618 team and has compared volumes defined on PET scan defined according to different methods based on intensity or S.U.V. to the tumour volume determined on CT scan by radio physicist. We have compared those volumes with histological volume that we considered for reference. Four patients have been included. They had 18 F-F.D.G. PET scan followed by complete tumoral removal surgery. Specific histological procedure allowed to define complete size of the tumor in re expanded lung. Comparatively to pathology, the volumes obtained using I max 40 and I max 50 are all underestimated. The volumes defined by Black's et al. method are under evaluated for the two largest tumours (15.8% to 22%) and overestimated for the two smallest ones (17.9 to 82.9%). Nestle's et al. method, using β = 0.15, correctly estimates two tumor volumes over 2 cm, but overestimates the two small tumors (79.6 to 124%). Finally, the corrected Nestle's et al. formula (using β = 0.264) overestimates three tumours. Volumes defined on CT scan by radio physicist are correct for one lesion, underestimated for one and overestimated for two other ones (44 and 179.5%). Nestle's et al. method seems to be the most accurate for tumours over 2 cm of

  13. MoDOT pavement preservation research program volume IV, pavement evaluation tools-data collection methods.

    Science.gov (United States)

    2015-10-01

    The overarching goal of the MoDOT Pavement Preservation Research Program, Task 3: Pavement Evaluation Tools Data : Collection Methods was to identify and evaluate methods to rapidly obtain network-level and project-level information relevant to :...

  14. SUSTAINABLE CONCRETE FOR WIND TURBINE FOUNDATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    BERNDT,M.L.

    2004-06-01

    The use of wind power to generate electricity continues to grow, especially given commitments by various countries throughout the world to ensure that a significant percentage of energy comes from renewable sources. In order to meet such objectives, increasingly larger turbines with higher capacity are being developed. The engineering aspects of larger turbine development tend to focus on design and materials for blades and towers. However, foundations are also a critical component of large wind turbines and represent a significant cost of wind energy projects. Ongoing wind research at BNL is examining two areas: (a) structural response analysis of wind turbine-tower-foundation systems and (b) materials engineering of foundations. This work is investigating the dynamic interactions in wind turbine systems, which in turn assists the wind industry in achieving improved reliability and more cost efficient foundation designs. The results reported herein cover initial studies of concrete mix designs for large wind turbine foundations and how these may be tailored to reduce cost and incorporate sustainability and life cycle concepts. The approach taken was to investigate material substitutions so that the environmental, energy and CO{sub 2}-impact of concrete could be reduced. The use of high volumes of ''waste'' materials in concrete was examined. These materials included fly ash, blast furnace slag and recycled concrete aggregate. In addition, the use of steel fiber reinforcement as a means to improve mechanical properties and potentially reduce the amount of bar reinforcement in concrete foundations was studied. Four basic mixes were considered. These were: (1) conventional mix with no material substitutions, (2) 50% replacement of cement with fly ash, (3) 50% replacement of cement with blast furnace slag and (4) 25% replacement of cement with fly ash and 25% replacement with blast furnace slag. Variations on these mixes included the addition of 1

  15. Antithetic Foundations of Economics

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2011-03-01

    Full Text Available This paper aims at decrypting the manner in which the foundations of Economics as a science and the meanings of the relevant explanatory formulas are being shaped. My analytical endeavor focuses on understanding the peculiarities of what is referred to as the object of study of the science known as Economics, an academic synthesis of concept-related breakthroughs regarding economicity. The explicit purpose of this analysis is to identify perennial benchmarks in economic cognition whereby this ensures its consistency. The implicit purpose is to shape a cognitive model in line with the specifics of the conceptual universe of Economics, as well as with the sources of the economic realities that are subject to a sui-generis relativism. The primary benefit of this endeavor consists in systemizing the conceptual prospects with an antithetic nature that allow for the explanations of the state of economic rationality and generate the understanding of what the source of economicity is and how it behaves. As such, the conclusions are marked by the stringent need of more precisely defining economic knowledge in order to match the changing nature of economic reality, as an expression that embraces the meeting point of two ontological vistas that are methodologically separated by some theories: human nature and human condition. Economics as a science thus features, apart from a conceptual substrate that needs to be spotted, an ontological background that needs to be revealed. The role played by this background appears to be most frequently ignored. The joint identification of both direct and contextual determinants for a sensitive area of humankind, i.e. the economy, is a direction to be followed by the royal path of rational knowledge.

  16. Predicting emergency department volume using forecasting methods to create a "surge response" for noncrisis events.

    Science.gov (United States)

    Chase, Valerie J; Cohn, Amy E M; Peterson, Timothy A; Lavieri, Mariel S

    2012-05-01

    This study investigated whether emergency department (ED) variables could be used in mathematical models to predict a future surge in ED volume based on recent levels of use of physician capacity. The models may be used to guide decisions related to on-call staffing in non-crisis-related surges of patient volume. A retrospective analysis was conducted using information spanning July 2009 through June 2010 from a large urban teaching hospital with a Level I trauma center. A comparison of significance was used to assess the impact of multiple patient-specific variables on the state of the ED. Physician capacity was modeled based on historical physician treatment capacity and productivity. Binary logistic regression analysis was used to determine the probability that the available physician capacity would be sufficient to treat all patients forecasted to arrive in the next time period. The prediction horizons used were 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 8 hours, and 12 hours. Five consecutive months of patient data from July 2010 through November 2010, similar to the data used to generate the models, was used to validate the models. Positive predictive values, Type I and Type II errors, and real-time accuracy in predicting noncrisis surge events were used to evaluate the forecast accuracy of the models. The ratio of new patients requiring treatment over total physician capacity (termed the care utilization ratio [CUR]) was deemed a robust predictor of the state of the ED (with a CUR greater than 1 indicating that the physician capacity would not be sufficient to treat all patients forecasted to arrive). Prediction intervals of 30 minutes, 8 hours, and 12 hours performed best of all models analyzed, with deviances of 1.000, 0.951, and 0.864, respectively. A 95% significance was used to validate the models against the July 2010 through November 2010 data set. Positive predictive values ranged from 0.738 to 0.872, true positives ranged from 74% to 94%, and

  17. Coupled numerical approach combining finite volume and lattice Boltzmann methods for multi-scale multi-physicochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li; He, Ya-Ling [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Kang, Qinjun [Computational Earth Science Group (EES-16), Los Alamos National Laboratory, Los Alamos, NM (United States); Tao, Wen-Quan, E-mail: wqtao@mail.xjtu.edu.cn [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2013-12-15

    A coupled (hybrid) simulation strategy spatially combining the finite volume method (FVM) and the lattice Boltzmann method (LBM), called CFVLBM, is developed to simulate coupled multi-scale multi-physicochemical processes. In the CFVLBM, computational domain of multi-scale problems is divided into two sub-domains, i.e., an open, free fluid region and a region filled with porous materials. The FVM and LBM are used for these two regions, respectively, with information exchanged at the interface between the two sub-domains. A general reconstruction operator (RO) is proposed to derive the distribution functions in the LBM from the corresponding macro scalar, the governing equation of which obeys the convection–diffusion equation. The CFVLBM and the RO are validated in several typical physicochemical problems and then are applied to simulate complex multi-scale coupled fluid flow, heat transfer, mass transport, and chemical reaction in a wall-coated micro reactor. The maximum ratio of the grid size between the FVM and LBM regions is explored and discussed. -- Highlights: •A coupled simulation strategy for simulating multi-scale phenomena is developed. •Finite volume method and lattice Boltzmann method are coupled. •A reconstruction operator is derived to transfer information at the sub-domains interface. •Coupled multi-scale multiple physicochemical processes in micro reactor are simulated. •Techniques to save computational resources and improve the efficiency are discussed.

  18. Finite Volume Methods for Incompressible Navier-Stokes Equations on Collocated Grids with Nonconformal Interfaces

    DEFF Research Database (Denmark)

    Kolmogorov, Dmitry

    turbine computations, collocated grid-based SIMPLE-like algorithms are developed for computations on block-structured grids with nonconformal interfaces. A technique to enhance both the convergence speed and the solution accuracy of the SIMPLE-like algorithms is presented. The erroneous behavior, which...... versions of the SIMPLE algorithm. The new technique is implemented in an existing conservative 2nd order finite-volume scheme flow solver (EllipSys), which is extended to cope with grids with nonconformal interfaces. The behavior of the discrete Navier-Stokes equations is discussed in detail...... Block LU relaxation scheme is shown to possess several optimal conditions, which enables to preserve high efficiency of the multigrid solver on both conformal and nonconformal grids. The developments are done using a parallel MPI algorithm, which can handle multiple numbers of interfaces with multiple...

  19. On the problem of low-temperature air adsorption studies by the volume method

    International Nuclear Information System (INIS)

    Gur'yanov, V.V.; Gashin, V.M.; Shcherbakov, V.P.; Misin, M.S.; Sizova, G.P.

    1975-01-01

    The properties of a porous structure and the adsorption of a series of carbon adsorbents at 77 K were studied. It was shown that isotherms may be constructed within the framework of the theory of volume filling only for a degree of filling of theta>20.5. Deviations from theoretical curves are observed with practically no accumulation in the high-vacuum equipment of carbon-adsorbed helium, hydrogen, and neon. Therefore the initial parts of the air-adsorption isotherm at 77 K may not be used for characterizing the adsorption properties and parameters of the porous structure of a microporous adsorbent. The effect of adsorbent microporosity on the adsorption isotherm begins to appear only when the pressure of the poorly sorbed components of the air is less than the total pressure of the nitrogen and oxygen

  20. A large volume striped bass egg incubation chamber: design and comparison with a traditional method

    Science.gov (United States)

    Harper, C.J.

    2009-01-01

    I conducted a comparative study of a new jar design (experimental chamber) with a standard egg incubation vessel (McDonald jar). Experimental chambers measured 0.4 m in diameter by 1.3 m in height and had a volume of 200 L. McDonald hatching jars measured 16 cm in diameter by 45 cm in height and had a volume of 6 L. Post-hatch survival was estimated at 48, 96 and 144 h. Stocking rates resulted in an average egg density of 21.9 eggs ml-1 (range = 21.6 – 22.1) for McDonald jars and 10.9 eggs ml-1 (range = 7.0 – 16.8) for experimental chambers. I was unable to detect an effect of container type on survival to 48, 96 or 144 h. At 144 h striped bass fry survival averaged 37.3% for McDonald jars and 34.2% for experimental chambers. Survival among replicates was significantly different. Survival of striped bass significantly decreased between 96 and 144 h. Mean survival among replicates ranged from 12.4 to 57.3%. I was unable to detect an effect of initial stocking density on survival. Experimental jars allow for incubation of a larger number of eggs in a much smaller space. As hatchery production is often limited by space or water supply, experimental chambers offer an alternative to extending spawning activities, thereby reducing manpower and cost. However, the increase in the number of eggs per rearing container does increase the risk associated with catastrophic loss of a production unit. I conclude the experimental chamber is suitable for striped bass egg incubation.