bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time interval gating for analysis of cell function using flow cytometry
Authors: Durack Gary , Lawler Gretchen , Kelley Steve , Ragheb Kathy , Roth R. A. , Ganey P. , Robinson J. Paul 
Published: August 2005

AbstractWe propose a method which significantly shortens the time required for both the collection and analysis of data derived from multiple sample, flow cytometric kinetic assays. We have defined the term Time Interval Gating (TIG) to describe this method. TIG effectively allows one flow cytometer to concurrently monitor several samples over the course of a kinetic assay. Data for all samples are stored in a single FCS 2.0 compatible listmode data file which we refer to as the TIG data file. TIG is adaptable to most commerical flow cytometers. Standard listmode analysis software can be used to analyze the TIG data files and correlate any combination of tubes and/or time intervals from the assay. Results for the entire assay can be displayed on a single two parameter plot. This paper describes how TIG is applied to neutrophil oxidative burst measurement using a standard EPICS Elite flow cytometer. In this assay, 11 samples were each monitored for 30 min to identify the extent to which volatile organic chemicals (VOCs) inhibited the oxidation of DCFH in stimulated neutrophils. TIG makes the oxidative burst assay practical for high volume screening by reducing the overall flow cytometer and analysis time required by a factor of ten. In addition, TIG provides an organized approach to managing data acquisition on instruments equipped with automated sampling systems.
Natural killer function in flow cytometry: Identification of human lymphoid subsets able to bind to the NK sensitive target K562
Authors: Vitale M. , Zamai L. , Neri L. M. , Manzoli L. , Facchini A. , Papa S. 
Published: August 2005

AbstractNK cells are a phenotypically, morphologically and functionally heterogeneous population. This has led to the current thought that the non‐MHC restricted cytotoxity is a cellular function that can be associated to different phenotypes. The recognition of the target cell and the conjugate formation is always the first step that eventually leads to the lysis of target. Characterization of the phenotypical pattern of the cells able to bind to K562 targets is the purpose of this study. A multiparametric flow cytometry binding assay has been employed to identify the different K562‐bound lymphocyte subsets. In particular, cells that coexpress the CD16 and CD8 antigens (CD16+8dim+) showed a significantly higher binding capacity than their CD16+8− counterpart. Moreover, the highest binding values have been found in cells that did not express the CD16 antigen at all, but still expressed the CD8dim antigen, such as the small CD8dim+3+ population. These data show that, the NK lytic function being dependent on binding, minor subpopulations must be considered among effector cells, which might correspond to different lytic activities. None of the previously published methodologies that analyze conjugates by flow cytometry or fluorescence microscopy were able to measure the binding capacity of small, double stained, lymphocyte subsets.
Amphotericin B susceptibility testing of Candida species by flow cytometry
Authors: O'Gorman Maurice R. G. , Hopfer Roy L. 
Published: August 2005

AbstractWe have developed an 8 hr flow cytometry (FCM) method for assessing susceptibility of yeasts to amphotericin B (AmpB). The method detects both high‐level and relative‐resistance to the drug. Variables found to affect fluorescence of control and AmpB treated cells included pH, presence of glucose, incubation conditions, concentration and length of exposure to both AmpB and ethidium bromide (ETBR), and the degree of resistance to AmpB. The FCM method was optimized based on increased red fluorescence intensity (RF), decreased forward angle light scatter (FALS), and a negative gating technique. A dose response was seen between 0.1 and 10 μg AmpB/ml for the susceptible control strain. Greater than 50% of cells from all susceptible strains tested transfer into the negative gate when exposed to 2.5 μg Amp B/ml while fewer than 5% of cells of the highly resistant C. tropicalis (ATCC 28707) are affected at concentrations up to 20μg/ml. This method may provide a more accurate assessment of Amp B susceptibility than conventional tube dilution methods.
Subsidence above volumetric and waterdrive gas reservoirs
Authors: Schrefler B. A. , Lewis R. W. , Majorana C. 
Published: August 2005

AbstractA fully coupled consolidation model has been developed for the simulation of the surface subsidence above gas reservoirs. The model is based on the Biot Theory and the material balance equation for hydrocarbon reservoirs. The model is extremely versatile and can handle such complex situations as vertical cross‐sections where several gas reservoirs and aquifers are exploited at different levels. Computer runs were used to generate several reservoir formation profiles and the surface subsidence bowl for a variety of conditions. These results indicate the importance of various parameters which are disregarded in proelasticity models.
Projection conditions on the vorticity in viscous incompressible flows
Authors: Quartapelle L. , Valz‐Gris F. 
Published: August 2005

AbstractThe problem of establishing appropriate conditions for the vorticity transport equation is considered. It is shown that, in viscous incompressible flows, the boundary conditions on the velocity imply conditions of an integral type on the vorticity. These conditions determine a projection of the vorticity field on the linear manifold of the harmonic vector fields. Some computational consequences of the above result in two‐dimensional calculations by means of the nonprimitive variables, stream function and vorticity, are examined. As an example of the application of the discrete analogue of the projection conditions, numerical solutions of the driven cavity problem are reported.
Effect of open boundary condition on numerical simulation of three‐dimensional hydrothermal behavior of Biscayne Bay, Florida
Authors: Sengupta Subrata , Miller H. P. , Lee Samuel S. 
Published: August 2005

AbstractA three‐dimensional time dependent free‐surface model has been used to simulate the velocity and temperature distributions in Biscayne Bay, an estuarine basin in South Florida. Comparisons with tide gauge data and airborne infrared temperature data have been made. Analyses of three‐dimensional velocity structure, phase relationships of velocity with depth and horizontal location have been conducted.One of the major concerns with three‐dimensional models is the specification of conditions at open‐boundaries, since it is rare that complete time dependent variations of variables at these boundaries are available. Two sets of approximate boundary conditions at the Biscayne Bay‐Atlantic Ocean interface have been used for computations. It was found that specification of averaged surface height variation at open boundaries yield significantly better results than specification of estimated values of velocity.
The implementation of normal and/or tangential boundary conditions in finite element codes for incompressible fluid flow
Authors: Engelman M. S. , Sani R. L. , Gresho P. M. 
Published: August 2005

AbstractVarious techniques for implementing normal and/or tangential boundary conditions in finite element codes are reviewed. The principle of global conservation of mass is used to define a unique direction for the outward pointing normal vector at any node on an irregular boundary of a domain containing an incompressible fluid. This information permits the consistent and unambiguous application of essential or natural boundary conditions (or any combination thereof) on the domain boundary regardless of boundary shape or orientation with respect to the co‐ordinate directions in both two and three dimensions. Several numerical examples are presented which demonstrate the effectiveness of the recommended technique.
Longshore boundary conditions for numerical wave models
Authors: Austin D. Ian , Bettess Peter 
Published: August 2005

AbstractThe problem of truncating nearshore finite element wave models is addressed. Incorrect treatment of the artificial boundaries of the model will cause spurious wave reflections. Three methods for dealing with these boundaries: application of constraints, use of the Smith condition and longshore dampers, are proposed. Numerical results show the dampers to be the best method.
Numerical solution of subsonic and transonic cascade flows
Authors: Habashi W. G. , Kotiuga P. L. 
Published: August 2005

AbstractIn this work a study of the application of the finite element method to transonic flows in axial turbomachines is undertaken.Solution techniques capable of accurately predicting flows from the incompressible regime up to the establishment of shocks in the transonic regime are presented. In the subsonic and shockless transonic regimes a local linearization method capable of very rapid convergence is used. In the full transonic regime the artificial compressibility method is employed to exclude downstream influences in the supersonic regions. The two approaches can be combined in a unified package and appropriate switches introduced to select the relevant method in any flow regime.
A survey of some second‐order difference schemes for the steady‐state convection–diffusion equation
Authors: Gupta Murli M. 
Published: August 2005

AbstractThis paper presents a survey of several finite difference schemes for the steady‐state convection–diffusion equation in one and two dimensions. Most difference schemes have O(h2) truncation error. The behaviour of these schemes on a one‐dimensional model problem is analysed in detail, especially for the case when convection dominates diffusion. It is concluded that none of these schemes is universally second order. One recently proposed scheme is found to yield highly inaccurate solutions for the case of practical interest, i.e. when convection dominates diffusion. Extensions to two and threedimensions are also discussed.
Numerical simulation of liquefied fuel spills: I. Instantaneous release into a confined area
Authors: Brandeis Julius , Kansa Edward J. 
Published: August 2005

AbstractThe shallow‐water equations in radial symmetry are solved numerically to simulate the collapse of a cylindrical liquid column into an area surrounded by a concentric dike. The following three subcases of this problem are considered: a liquid column collapsing onto a layer of the same liquid, a liquid column collapsing onto a solid surface, and a column of lighter liquid collapsing onto a heavier liquid (i.e. liquefied natural gas (LNG) spilled onto water). The results for the three categories are compared and the differences and similarities between them are analysed.
Numerical simulation of liquefied fuel spills: II. Instantaneous and continuous LNG spills on an unconfined water surface
Authors: Brandeis Julius , Ermak Donald L. 
Published: August 2005

AbstractA simple numerical model based on the shallow water equations in radial symmetry is used to simulate both instantaneous and continuous spills of liquefied natural gas (LNG) onto a water surface. Using the computed results, a study is made of the similarities and differences in the pool structure resulting from the two types of spills. For instantaneous spills a relation linear on a logarithmic plot is suggested between the maximum pool size and the spill volume. The effects of shear forces and surface cohesivity on the evolution of the spill are also examined.
A frontal method based solution of the quasi‐three‐dimensional finite element model for interconnected aquifer systems. Steady and unsteady equations, with the E.N.S. method for fluid mass balance evaluation
Authors: Sartori L. , Peverieri G. 
Published: August 2005

AbstractThe quasi‐three‐dimensional equations controlling the groundwater flow in heterogeneous and interconnected aquifer systems are discretized by finite elements, considering also the aquifer branching. A new method for fluid mass balance evaluation based on the equivalent nodal source (E.N.S.) concept allows one to express the balance in conservative terms, and interpret finite element equations as nodal balance equations. The solution of the system is based on the frontal method. Use of substructures limits the frontal increase in correspondence to the aquifer branching. In the steady state, the frontal method is integrated with an iterative solution technique to eliminate the frontal increase caused by the presence of aquitards. It converges very rapidly, using a forcing technique with an automatic parameter definition. In the unsteady case the same scope is achieved using a predictor‐corrector procedure which employs the Crank‐Nicolson method in the corrector phase.This very stable procedure permits use of fairly long time‐steps and concerns the case of source terms depending on piezometry (problem of interaction between water table and river). This method has been tested with several fairly complex cases.
Lifting aerofoil calculation using the boundary element method
Authors: Carey G. F. , Kim S. W. 
Published: August 2005

AbstractThe bbundary integral formulation and boundary element method are extended to include lifting flow problems. This involves inclusion of a branch cut in the flow field and imposition of a Kutta condition to determine the circulation, Γ Additional boundary integral contributions arise from the cut surface. Techniques for calculating Γ are developed and we treat, in particular, a superposition procedure which permits very efficient computation. Numerical results are presented for an NACA0012 aerofoil at several angles of attack.
Wave envelope and infinite elements for acoustical radiation
Authors: Astley R. J. 
Published: August 2005

AbstractFinite element models are presented for the calculation of near and far field acoustical radiation. These models are applied to the specific problem of fan noise radiation from axisymmetric turbofan inlets. In all cases conventional acoustic finite elements are used within an inner region close to the inlet. The far field is represented by infinite elements or wave envelope elements. Theory and results are presented for the case with zero mean flow. Comparisons of computed data with analytic solutions and measured values establish the utility of both the infinite element and wave envelope element schemes in determining the near field values of acoustical pressure. The wave envelope scheme is shown to be effective also in the far field. Both schemes use meshes an order of magnitude more sparse that would be required in conventional numerical discretizations, and may consequently be applied at modest computational cost.
Incompressible flow in a rapidly rotating cylinder with a source/sink distribution in the lateral wall and a free inner boundary
Authors: Ribando Robert J. 
Published: August 2005

AbstractThe flow of an incompressible fluid in a rapidly rotating right circular cylinder is considered. A source/sink mass distribution at the lateral wall, which is azimuthally uniform and symmetric across the midplane, causes a deviation from wheel flow. The container is only partially full and the inner free surface is allowed to deviate slightly from the vertical. A finite‐difference solution of the full axisymmetric, non‐linear governing equations was used to obtain the flow field. A special implicit technique for the Coriolis terms which maintains geostrophy was developed and is described. The results obtained for a low Rossby number flow compare quite favourably with the linearized solution. Results are also presented for a case wherein the non‐linear terms are important.
Numerically induced oscillations in finite element approximations to the shallow water equations
Authors: Walters Roy A. 
Published: August 2005

AbstractNumerical noise has been a problem with finite element solutions to the shallow water equations. Two methods used to reduce the noise level are evaluated, and these results are compared with published results for equal‐order interpolations. The two methods are mixed‐interpolation (quadratic interpolation for velocity and linear interpolation for sea level) and a spectral form of the wave equation. Whereas mixed interpolation removes the troublesome sea level mode, it can still have considerable noise in velocity. The spectral wave equation is efficient and does not contain the spurious eigenmodes which contribute to high noise levels.
A stream function finite element solution for two‐dimensional natural convection with accurate representation of nusselt number variations near a corner
Authors: Betts P. L. , Haroutunian V. 
Published: August 2005

AbstractA finite element stream function formulation is presented for the solution to the two‐dimensional double‐glazing problem. Laminar flow with constant properties is considered and the Boussinesq approximation used. A restricted variational principle is used, in conjunction with a triangular finite element of C1 continuity, to discretize the two coupled governing partial differential equations (4th order in stream function and second order in temperature). The resulting non‐linear system of equations is solved in a segregated (decoupled) manner by the Newton‐Raphson linearizing technique.Results are produced for the standard test case of an upright square cavity. These are for Rayleigh numbers in the range 103−105, with a Prandtl number of 0.71. Comparisons are made with benchmark results presented at the 1981 International Comparison study in Venice. In the discussion of results, emphasis is placed on the variation of local Nusselt number along the isothermal walls, particularly near the corner. This reveals a noticeable source of error in the evaluation of the maximum Nusselt number by lower order discretization methods.
An ‘assumed deviatoric stress‐pressure‐velocity’ mixed finite element method for unsteady, convective, incompressible viscous flow: Part II: Computational studies
Authors: Yang Chien‐Tung , Atluri Satya N. 
Published: August 2005

AbstractIn Part I of this paper we presented a mixed finite element method, for solving unsteady, incompressible, convective flows, based on assumed ‘deviatoric stress–velocity–pressure’ fields in each element, which have the features: (i) the convective term is treated by the usual Galerkin technique; (ii) the unknowns in the global system of finite element equations are the nodal velocities, and the ‘constant term’ in the arbitrary pressure field over each element; and (iii) exact integrations are performed over each element.In this paper we present numerical studies, both for steady as well as unsteady cases, of the problems: (a) the driven cavity, (b) Jeffry–Hamel flow in a channel, (c) flow over a ‘backward’ or ‘downstream’ facing step, and (d) flow over a square step. All these problems are two‐dimensional in nature, although certain 3‐D solutions are to be presented in a separate paper. The present results are compared with those which are available in the literature and are based on alternative approaches to treat incompressibility and convective acceleration. The possible merits of the present method are thus pointed out.
Coating flow theory by finite element and asymptotic analysis of the navier‐stokes system
Authors: Kistler S. F. , Scriven L. E. 
Published: August 2005

AbstractCoating flows are laminar free surface flows, preferably steady and two‐dimensional, by which a liquid film is deposited on a substrate. Their theory rests on mass and momentum accounting for which Galerkin's weighted residual method, finite element basis functions, isoparametric mappings, and a new free surface parametrization prove particularly well‐suited, especially in coping with the highly deformed free boundaries, irregular flow domains, and the singular nature of static and dynamic contact lines where fluid interfaces intersect solid surfaces. Typically, short forming zones of rapidly rearranging two‐dimensional flow merge with simpler asymptotic regimes of developing or developed flow upstream and downstream. The two‐dimensional computational domain can be shrunk in size by imposing boundary conditions from asymptotic analysis of those regimes or by matching to one‐dimensional finite element solutions of asymptotic equations.The theory is laid out with special attention to conditions at free surfaces, contact lines, and open inflow and outflow boundaries. Efficient computation of predictions is described with emphasis on a grand Newton iteration that converges rapidly and brings other benefits. Sample results for curtain coating and roll coating flows of Newtonian liquids illustrate the power and effectiveness of the theory.
A natural interpolation formula for Prandtl's singular integrodifferential equation
Authors: Ioakimidis N. I. 
Published: August 2005

AbstractPrandtl's singular integrodifferential equation and related equations appear in problems of aerofoil and propeller theory in fluid mechanics. Here a natural interpolation formula for the approximation to the unknwon function of Prandtl's equation when this is solved numerically by the direct quadrature method, based on the Gauss‐ and Lobatto‐Chebyshev quadrature rules, is proposed. This interpolation formula is analogous to Nyström's natural interpolation formula for Fredholm integral equations of the second kind and the corresponding formula for singular integral equations. Numerical applications of the same formula are also made.
Finite element method for unsteady MHD flow through pipes with arbitrary wall conductivity
Authors: Singh Bani , Lal Jia 
Published: August 2005

AbstractA finite element method is given to obtain the numerical solution of the coupled equations in velocity and magnetic field for unsteady MHD flow through a pipe having arbitrarily conducting walls. Pipes of rectangular, circular and triangular sections have been taken for illustration. Computations have been carried out for different Hartmann numbers and wall conductivity at various time levels. It is found that if the wall conductivity increases, the flux through a section decreases. The same is the effect of increasing the Hartmann number. It is also observed that the steady state is approached at a faster rate for larger Hartmann numbers or larger wall conductivity. Selected graphs are given showing the behaviour of velocity, induced magnetic field and flux across a section.
Modelling fluid flow in fractured‐porous rock masses by finite‐element techniques
Authors: Baca R. G. , Arnett R. C. , Langford D. W. 
Published: August 2005

AbstractOne of the major difficulties of modelling fluid flow processes in hard‐rock geologies is the complex nature of the porosity systems. Hydraulic behaviour in these rock masses is characterized by both porous and fractured interflow zones. Traditionally, fractured‐porous rocks have been modelled as an equivalent porous medium or as a system of fractures separated by impermeable blocks. A new method is proposed that unifies these two approaches for modelling fluid flow processes in fractured‐porous media. The basic idea is to use a combination of isoparametric elements for the porous zones and line elements for the fractures. The coupling between the governing equations for each element type is achieved using the superposition principle. The effectiveness of the new approach is demonstrated by comparing numerical solutions with known solutions for problems of flow and solute transport in fractured‐porous media.