The Experts below are selected from a list of 79179 Experts worldwide ranked by ideXlab platform

William B Guertal - One of the best experts on this subject based on the ideXlab platform.

  • Modeling flow and transport in unsaturated fractured rock: an evaluation of the Continuum Approach.
    Journal of contaminant hydrology, 2003
    Co-Authors: Hui-hai Liu, Charles B Haukwa, C Fredrik Ahlers, Gudmundur S Bodvarsson, Alan L Flint, William B Guertal
    Abstract:

    Because the Continuum Approach is relatively simple and straightforward to implement, it has been commonly used in modeling flow and transport in unsaturated fractured rock. However, the usefulness of this Approach can be questioned in terms of its adequacy for representing fingering flow and transport in unsaturated fractured rock. The Continuum Approach thus needs to be evaluated carefully by comparing simulation results with field observations directly related to unsaturated flow and transport processes. This paper reports on such an evaluation, based on a combination of model calibration and prediction, using data from an infiltration test carried out in a densely fractured rock within the unsaturated zone of Yucca Mountain, Nevada. Comparisons between experimental and modeling results show that the Continuum Approach may be able to capture important features of flow and transport processes observed from the test. The modeling results also show that matrix diffusion may have a significant effect on the overall transport behavior in unsaturated fractured rocks, which can be used to estimate effective fracture-matrix interface areas based on tracer transport data. While more theoretical, numerical, and experimental studies are needed to provide a conclusive evaluation, this study suggests that the Continuum Approach is useful for modeling flow and transport in unsaturated, densely fractured rock.

Neelesh A Patankar - One of the best experts on this subject based on the ideXlab platform.

  • A Continuum Approach to reproduce molecular-scale slip behaviour
    Journal of Fluid Mechanics, 2010
    Co-Authors: Neelesh A Patankar
    Abstract:

    In this work we explore if it is possible to reproduce molecular-scale slip behaviour by using Continuum equations. To that end it is noted that molecular-scale slip is affected by three factors: (i) near the wall, the fluid experiences a potential because of the wall; (ii) the fluid density responds to that potential, and hence, fluid compressibility is relevant; and (iii) the fluid can lose momentum to the wall. To incorporate these features we simulate shear flow of a compressible fluid between two walls in the presence of a potential. Compressibility effect is found to be important only in the near-wall region. The slip length is calculated from the mean velocity profile. The slip-length-versus-shear-rate trend is similar to that in molecular dynamic calculations. First, there is a constant value of the slip length at low shear rates. Then, the slip length increases beyond a critical shear rate. Lastly, the slip length reaches another constant value if the wall momentum loss parameter is non-zero. The scaling for the critical shear rate emerges from our results. The value of the slip length increases if the wall potential is less corrugated and if the momentum loss to the wall is low. An understanding of the overall force balance during various slip modes emerges from the governing equations.

Robert C. Bird - One of the best experts on this subject based on the ideXlab platform.

  • Rethinking Wrongful Discharge: A Continuum Approach
    2004
    Co-Authors: Robert C. Bird
    Abstract:

    Over two hundred articles have been written critiquing employment at-will and wrongful discharge since 1985. However, little radical change has occurred in state courts on this issue in some time. In spite of strong judicial resistance to modify employment at will, wrongful discharge scholarship is still saturated with normative criticism of the doctrine. Scholarship in this area can deliver a valued benefit if it focuses on understanding wrongful discharge systematically as a coherent body of law. This article adopts a descriptive-Continuum Approach that organizes wrongful discharge law into five distinct and interrelated categories. This article also provides a sequential, systematic method for classifying employer discharges within the broad Continuum of wrongful discharge law. Finally, this article uses a case study to highlight the benefits of the descriptive-Continuum Approach for courts, employers and employees alike.

  • Rethinking Wrongful Discharge: A Descriptive-Continuum Approach
    SSRN Electronic Journal, 2003
    Co-Authors: Robert C. Bird
    Abstract:

    Over two hundred articles have been written critiquing employment at-will and wrongful discharge since 1985. However, little radical change has occurred in state courts on this issue in some time. In spite of strong judicial resistance to modify employment at will, wrongful discharge scholarship is still saturated with normative criticism of the doctrine. Scholarship in this area can deliver a valued benefit if it focuses on understanding wrongful discharge systematically as a coherent body of law. This article adopts a "descriptive-Continuum" Approach that organizes wrongful discharge law into five distinct and interrelated categories. This article also provides a sequential, systematic method for classifying employer discharges within the broad Continuum of wrongful discharge law. Finally, this article uses a case study to highlight the benefits of the descriptive-Continuum Approach for courts, employers and employees alike.

Hui-hai Liu - One of the best experts on this subject based on the ideXlab platform.

  • Modeling flow and transport in unsaturated fractured rock: an evaluation of the Continuum Approach.
    Journal of contaminant hydrology, 2003
    Co-Authors: Hui-hai Liu, Charles B Haukwa, C Fredrik Ahlers, Gudmundur S Bodvarsson, Alan L Flint, William B Guertal
    Abstract:

    Because the Continuum Approach is relatively simple and straightforward to implement, it has been commonly used in modeling flow and transport in unsaturated fractured rock. However, the usefulness of this Approach can be questioned in terms of its adequacy for representing fingering flow and transport in unsaturated fractured rock. The Continuum Approach thus needs to be evaluated carefully by comparing simulation results with field observations directly related to unsaturated flow and transport processes. This paper reports on such an evaluation, based on a combination of model calibration and prediction, using data from an infiltration test carried out in a densely fractured rock within the unsaturated zone of Yucca Mountain, Nevada. Comparisons between experimental and modeling results show that the Continuum Approach may be able to capture important features of flow and transport processes observed from the test. The modeling results also show that matrix diffusion may have a significant effect on the overall transport behavior in unsaturated fractured rocks, which can be used to estimate effective fracture-matrix interface areas based on tracer transport data. While more theoretical, numerical, and experimental studies are needed to provide a conclusive evaluation, this study suggests that the Continuum Approach is useful for modeling flow and transport in unsaturated, densely fractured rock.

El Mostafa Qannari - One of the best experts on this subject based on the ideXlab platform.

  • From Multiblock Partial Least Squares to Multiblock Redundancy Analysis. A Continuum Approach
    Informatica, 2011
    Co-Authors: Stéphanie Bougeard, El Mostafa Qannari, Coralie Lupo, Mohamed Hanafi
    Abstract:

    For the purpose of exploring and modelling the relationships between a dataset and several datasets, multiblock Partial Least Squares is a widely-used regression technique. It is designed as an extension of PLS which aims at linking two datasets. In the same vein, we propose an extension of Redundancy Analysis to the multiblock setting. We show that PLS and multiblock Redundancy Analysis aim at maximizing the same criterion but the constraints are different. From the solutions of both these Approaches, it turns out that they are the two end points of a Continuum Approach that we propose to investigate.

  • Continuum redundancy-PLS regression: A simple Continuum Approach
    Computational Statistics & Data Analysis, 2008
    Co-Authors: Stéphanie Bougeard, Mohamed Hanafi, El Mostafa Qannari
    Abstract:

    The relationships between two data sets are investigated. The aim is to predict one data set from the other. New formulations of Redundancy Analysis and Partial Least Square Regression (PLS) are discussed, clearly showing the connexions between these two popular methods. Moreover, it is shown that the Redundancy Analysis and PLS regression are the two end points of a Continuum Approach. Properties related to this Continuum Approach are discussed, showing how the multicolinearity problem is handled. The interest of the general strategy of analysis is illustrated on the basis of a data set pertaining to epidemiology.