BACKGROUND AND OBJECTIVES Maintenance hemodialysis (MHD) patients with larger body or fat mass have greater survival than normal to low mass. We hypothesized that mid-arm muscle circumference (MAMC), a conveniently measured surrogate of lean body mass (LBM), has stronger association with clinical outcomes than triceps skinfold (TSF), a surrogate of fat mass. DESIGN, SETTINGS, PARTICIPANTS, & ...

A digital imaging technique is used to characterize pore-scale structures and to predict fluid flow at the scale. Heterogeneity at the pore-scale can be assessed by the micro-Computed Tomography (micro-CT), which provides complicated boundary conditions of porous media, and it can also be identified by the numerical flow simulation using the lattice-Boltzmann method (LBM) on the digital image. ...

A new implementation of boundary condition based on the half-covolume and bounce-back rule for the non-equilibrium distribution function for the finite volume LBM is proposed here. The numerical simulation results for the expansion channel flow and driven cavity problem indicate that this method is workable for arbitrary meshes. In addition, the fourth order Runge–Kutta scheme is found to be a ...

An elevated total RBC volume (TRCV) in milliliters per kilogram of body weight has been an essential criterion for determining whether a person is polycythemic. This may be misleading in obese subjects as the TRCV per kilogram of fat is only one-tenth that of the TRCV of the lean body mass (LBM). Various formulas based on surface area have been used to account for this difference, but they are ...

The lattice Boltzmann method (LBM) is an increasingly popular approach for solving fluid flows in a wide range of applications. The LBM yields regular, data-parallel computations; hence, it is especially well fitted to massively parallel hardware such as graphics processing units (GPU). Up to now, though, single-GPU implementations of the LBM are of moderate practical interest since the on-boar...

Our recent efforts focusing on improving the lattice Boltzmann method (LBM) are introduced, including an incompressible LB model without compressible effect, a flexible thermal LBM with simple structure for Bousinesq fluids, and a robust boundary scheme. We use them to simulate the lid-driven cavity flow at Reynolds numbers 5000–50000, the natural convection due to internal heat generation in a...

In this paper we present a topology optimization technique applicable to a broad range of flow design problems. We propose also a discrete adjoint formulation effective for a wide class of Lattice Boltzmann Methods (LBM). This adjoint formulation is used to calculate sensitivity of the LBM solution to several type of parameters, both global and local. The numerical scheme for solving the adjoin...

The performance of many CFD applications, like the lattice Boltzmann method (LBM), on popular cluster computers can fall far short of the impressive peak performance numbers. Using a large scale LBM application, we demonstrate the different performance characteristics of modern supercomputers. Classical vector systems (NEC SX8) still combine excellent performance with a well established optimiz...

We describe a high-performance implementation of the lattice Boltzmann method (LBM) for sparse 3D geometries on graphic processors (GPU). The main contribution of this work is a data layout that allows to minimise the number of redundant memory transactions during the propagation step of LBM. We show that by using a uniform mesh of small three-dimensional tiles and a careful data placement it i...

Several factors such as respiratory muscle strength, lung compliance, resistance to airflow etc., affect the lung functions. Studies on pulmonary functions in relation to body composition are lacking. We hypothesized that lung functions both in the obese and the undernourished subjects would be reduced due to mechanical disadvantages. Therefore, the present study was designed with the aim to co...