scholarly journals Visualization of CD2 interaction with LFA-3 and determination of the two-dimensional dissociation constant for adhesion receptors in a contact area.

1996 ◽  
Vol 132 (3) ◽  
pp. 465-474 ◽  
Author(s):  
M L Dustin ◽  
L M Ferguson ◽  
P Y Chan ◽  
T A Springer ◽  
D E Golan
Keyword(s):  
Contact Area ◽  
Dissociation Constants ◽  
Three Dimensional ◽  
Lateral Diffusion ◽  
Solution Phase ◽  
Phospholipid Bilayer ◽  
Cell Contact ◽  
Two Dimensional ◽  
Adhesion Receptors ◽  
Dimensional Solution

Many adhesion receptors have high three-dimensional dissociation constants (Kd) for counter-receptors compared to the KdS of receptors for soluble extracellular ligands such as cytokines and hormones. Interaction of the T lymphocyte adhesion receptor CD2 with its counter-receptor, LFA-3, has a high solution-phase Kd (16 microM at 37 degrees C), yet the CD2/LFA-3 interaction serves as an effective adhesion mechanism. We have studied the interaction of CD2 with LFA-3 in the contact area between Jurkat T lymphoblasts and planar phospholipid bilayers containing purified, fluorescently labeled LFA-3. Redistribution and lateral mobility of LFA-3 were measured in contact areas as functions of the initial LFA-3 surface density and of time after contact of the cells with the bilayers. LFA-3 accumulated at sites of contact with a half-time of approximately 15 min, consistent with the previously determined kinetics of adhesion strengthening. The two-dimensional Kd for the CD2/LFA-3 interaction was 21 molecules/microns 2, which is lower than the surface densities of CD2 on T cells and LFA-3 on most target or stimulator cells. Thus, formation of CD2/LFA-3 complexes should be highly favored in physiological interactions. Comparison of the two-dimensional (membrane-bound) and three-dimensional (solution-phase) KdS suggest that cell-cell contact favors CD2/LFA-3 interaction to a greater extent than that predicted by the three-dimensional Kd and the intermembrane distance at the site of contact. LFA-3 molecules in the contact site were capable of lateral diffusion in the plane of the phospholipid bilayer and did not appear to be irreversibly trapped in the contact area, consistent with a rapid off-rate. These data provide insights into the function of low affinity interactions in adhesion.

A Model for Heat Transfer From Embedded Blood Vessels in Two-Dimensional Tissue Preparations

1995 ◽  
Vol 117 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Liang Zhu ◽  
Sheldon Weinbaum
Keyword(s):  
Heat Transfer ◽  
Blood Vessels ◽  
Three Dimensional ◽  
Tissue Preparation ◽  
Basic Solution ◽  
Two Dimensional ◽  
Dimensional Solution ◽  
Tissue Conductivity ◽  
Thermal Equilibration ◽  
Insight Into

Two-dimensional microvascular tissue preparations have been extensively used to study blood flow in the microcirculation, and, most recently, the mechanism of thermal equilibration between thermally significant countercurrent artery-vein pairs. In this paper, an approximate three-dimensional solution for the heat transfer from a periodic array of blood vessels in a tissue preparation of uniform thickness with surface convection is constructed using a newly derived fundamental solution for a Green’s function for this flow geometry. This approximate solution is exact when the ratio K′ of the blood to tissue conductivity is unity and a highly accurate approximation when K′ ≠ 1. This basic solution is applied to develop a model for the heat transfer from a countercurrent artery-vein pair in an exteriorized rat cremaster muscle preparation. The numerical results provide important new insight into the design of microvascular experiments in which the axial variation of the thermal equilibration in microvessels can be measured for the first time. The solutions also provide new insight into the design of fluted fins and microchips that are convectively cooled by internal pores.

scholarly journals Comparison of Two- and Three-Dimensional Flow Computations With Laser Anemometer Measurements in a Transonic Compressor Rotor

1983 ◽  
Vol 105 (3) ◽  
pp. 596-605 ◽  
Author(s):  
R. V. Chima ◽  
A. J. Strazisar
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Maximum Flow ◽  
Wave System ◽  
Two Dimensional ◽  
Dimensional Solution ◽  
Transonic Compressor ◽  
Function Solution ◽  
Compressor Rotor ◽  
Laser Anemometer

Two-and three-dimensional inviscid solutions for the flow within a transonic axial compressor rotor at design speed are compared to laser anemometer measurements at maximum flow and near stall operating points. Computational details of the two-dimensional axisymmetric stream function solution and the three-dimensional full Euler solution are described. Upstream of the rotor, the two and three-dimensional solutions for radial distribution of relative Mach number and total pressure agree well with the data. Within the bow wave system and the blade row, the axisymmetric two-dimensional solution shows only qualitative agreement with the data.

scholarly journals Comparison of Two and Three Dimensional Flow Computations With Laser Anemometer Measurements in a Transonic Compressor Rotor

1982 ◽  
Author(s):  
R. V. Chima ◽  
A. J. Strazisar
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Maximum Flow ◽  
Wave System ◽  
Two Dimensional ◽  
Dimensional Solution ◽  
Transonic Compressor ◽  
Function Solution ◽  
Compressor Rotor ◽  
Laser Anemometer

Two and three-dimensional inviscid solutions for the flow within a transonic axial compressor rotor at design speed are compared to laser anemometer measurements at maximum flow and near stall operating points. Computational details of the two-dimensional axisymmetric stream function solution and the three-dimensional full Euler solution are described. Upstream of rotor, the two-dimensional and three-dimensional solutions for radial distribution of relative Mach number and total pressure agree well with the data. Within the bow wave system and the blade row, the axisymmetric two-dimensional solution shows only qualitative agreement with the data.

Three-dimensional flow near a two-dimensional stagnation point

1967 ◽  
Vol 28 (1) ◽  
pp. 149-151 ◽  
Author(s):  
A. Davey ◽  
D. Schofield
Keyword(s):  
Boundary Layer ◽  
Numerical Solution ◽  
Stagnation Point ◽  
Incompressible Flow ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Solution ◽  
Boundary Layer Equations ◽  
Viscous Incompressible Flow

This paper shows the existence of a three-dimensional solution of the boundary-layer equations of viscous incompressible flow in the immediate neighbourhood of a two-dimensional stagnation point of attachment. The numerical solution has been obtained.

scholarly journals Maximal heat transfer between two parallel plates

2018 ◽  
Vol 851 ◽  
Author(s):  
Shingo Motoki ◽  
Genta Kawahara ◽  
Masaki Shimizu
Keyword(s):  
Heat Transfer ◽  
Velocity Field ◽  
Large Scale ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Two Dimensional ◽  
Parallel Plates ◽  
Solution Branch ◽  
Search Range ◽  
Dimensional Solution

The divergence-free time-independent velocity field has been determined so as to maximise heat transfer between two parallel plates with a constant temperature difference under the constraint of fixed total enstrophy. The present variational problem is the same as that first formulated by Hassanzadeh et al. (J. Fluid Mech., vol. 751, 2014, pp. 627–662); however, the search range for optimal states has been extended to a three-dimensional velocity field. A scaling of the Nusselt number $Nu$ with the Péclet number $Pe$ (i.e., the square root of the non-dimensionalised enstrophy with thermal diffusion time scale), $Nu\sim Pe^{2/3}$, has been found in the three-dimensional optimal states, corresponding to the asymptotic scaling with the Rayleigh number $Ra$, $Nu\sim Ra^{1/2}$, expected to appear in an ultimate state, and thus to the Taylor energy dissipation law in high-Reynolds-number turbulence. At $Pe\sim 10^{0}$, a two-dimensional array of large-scale convection rolls provides maximal heat transfer. A three-dimensional optimal solution emerges from bifurcation on the two-dimensional solution branch at $Pe\sim 10^{1}$, and the three-dimensional solution branch has been tracked up to $Pe\sim 10^{4}$ (corresponding to $Ra\approx 2.7\times 10^{6}$). At $Pe\gtrsim 10^{3}$, the optimised velocity fields consist of convection cells with hierarchical self-similar vortical structures, and the temperature fields exhibit a logarithmic-like mean profile near the walls.

Three-Dimensional Deformations

1996 ◽  
Author(s):  
T. T. C. Ting
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Anisotropic Elasticity ◽  
Two Dimensional ◽  
Elastic Solids ◽  
Elastic Materials ◽  
Dimensional Solution ◽  
Line Integral ◽  
Isotropic Elasticity ◽  
Anisotropic Elastic

There appears to be very little study, if any, on the extension of Stroh's formalism to three-dimensional deformations of anisotropic elastic materials. In most three-dimensional problems the analyses employ approaches that are remotely related to Stroh's two-dimensional formalism. This is not unexpected, since this has been the situation between two-dimensional and three-dimensional isotropic elasticity. However it needs not be the case for three-dimensional anisotropic elasticity. Much can be gained if a connection to the Stroh formalism can be established. Barnett and Lothe (1975a) appeared to be the only ones who made a connection between a three-dimensional solution and Stroh's two-dimensional formalism. Earlier, several investigators obtained the Green's function for the infinite anisotropic medium in term of a line integral on an oblique plane in the three-dimensional space. That line integral, as we will see here, is one of Barnett-Lothe tensors on an oblique plane. We propose in this chapter extensions and applications of Stroh's two-dimensional formalism to certain three-dimensional deformations of anisotropic elastic solids.

Two-Dimensional Green’s Functions for Elastic Bi-materials

1992 ◽  
Vol 59 (2) ◽  
pp. 321-327 ◽  
Author(s):  
J. L. Carvalho ◽  
J. H. Curran
Keyword(s):  
Boundary Element Method ◽  
Hydraulic Fracturing ◽  
Boundary Element ◽  
Plane Strain ◽  
Three Dimensional ◽  
Fundamental Solutions ◽  
Two Dimensional ◽  
Dimensional Solution ◽  
Dimensional Plane ◽  
Element Method

Two-dimensional plane-strain fundamental solutions for elastic bi-materials are developed using the nuclei of strain method. The method is a reduction of the threedimensional approach previously derived by Vijayakumar and Cormack. The structure of the three-dimensional solution is preserved and the two-dimensional nuclei of strain and their corresponding vector functions are reported in this paper. Application of these solutions to the boundary element method is demonstrated via a hydraulic fracturing example.

The Influence of a Free Surface on the Hydroelastic Stability of a Flat Panel

1972 ◽  
Vol 39 (1) ◽  
pp. 53-58 ◽  
Author(s):  
D. S. Weaver ◽  
T. E. Unny
Keyword(s):  
Free Surface ◽  
Three Dimensional ◽  
Surface Displacement ◽  
Two Dimensional ◽  
Flat Panel ◽  
Dimensional Solution ◽  
Dimensional Approximation ◽  
Free Surface Displacement

This paper examines the influence of a parallel free surface on the hydroelastic stability of a flat panel. A quasi-two-dimensional approximation is made for the free surface displacement and the results compared with the more general but cumbersome three-dimensional solution. This comparison shows that the former approach is quite reasonable as well as being considerably simpler and more instructive. It is found that the free surface has no effect for depth ratios greater than about one half and is stabilizing for smaller depth ratios.

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