We present new method for solving non-stationary advection equations based on the finite volume space discretization and the semi-implicit discretization in time. Its basic idea is that outflow from a cell is treated explicitly while inflow is treated implicitly. Since the matrix of the system in this new I2OE method is determined by the inflow fluxes it is an M-matrix yielding favourable solva...

I N A RECENT study of blood pressure response to intermittent flow and outflow of blood from the circulation (I), it was observed that after suddenly ceasing outflow and then beginning immediately the inflow of blood there usually followed in normal animals a series of damped oscillations in the blood pressure. This effect also occurred when the inflow of blood was suddenly stopped and was foll...

We apply the lattice Boltzmann equation (LBE) with multiple-relaxation-time (MRT) collision model to simulate laminar flows in two-dimensions (2D). In order to simulate flows in an unbounded domain with the LBE method, we need to address two issues: stretched nonuniform mesh and inflow and outflow boundary conditions. We use the interpolated grid stretching method to address the need of non-uni...

The ability to elicit distinct duty cycles from the same self-regulating microfluidic oscillator device would greatly enhance the versatility of this micro-machine as a tool, capable of recapitulating in vitro the diverse oscillatory processes that occur within natural systems. We report a novel approach to realize this using the coordinated modulation of input volumetric flow rate ratio and fl...

With HeartMate II (HMII) implants increasing so has the frequency of device exchange. However, identifying inflow cannula obstruction, pump thrombosis, or outflow obstruction as the mechanism of pump dysfunction can be difficult. Echocardiography, CT angiogram, and cardiac catheterization are not definitive in determining the location of pump failure. Therefore, intraoperative examination is of...

We describe a simple, inexpensive, and very effective method of achieving circumferential flow reduction during direct percutaneous cyanoacrylate embolization of a high-flow vascular malformation of the scalp. By using a plastic "cookie cutter" placed over the lesion and applying various degrees of pressure, both venous outflow from and arterial inflow into the lesion were limited. This flow re...

BACKGROUND AND PURPOSE Plaque formation at arterial bifurcations depends on vessel anatomy, particularly the relative sizes of the branches, and the ratio of the outflow to inflow area. The facts that carotid plaque is more common in men and that carotid bruits in the absence of stenosis are more frequent in women raise the possibility that there are sex differences in carotid bifurcation anato...

Background and Purpose—Why is carotid plaque often so strikingly asymmetrical within individuals, and why does the extent of disease vary so considerably between individuals with similar systemic risk factors? Variability of carotid bifurcation anatomy is a possible explanation. Flow models suggest that vessel anatomy, in particular vessel diameter and area ratios, affects plaque formation at a...

BACKGROUND AND PURPOSE Why is carotid plaque often so strikingly asymmetrical within individuals, and why does the extent of disease vary so considerably between individuals with similar systemic risk factors? Variability of carotid bifurcation anatomy is a possible explanation. Flow models suggest that vessel anatomy, in particular vessel diameter and area ratios, affects plaque formation at a...

We present the results from axisymmetric time-dependent hydrodynamical calculations of gas flows which are under the influence of gravity of a black hole in quasars. We assume that the flows are nonrotating and exposed to quasar radiation. We take into account X-ray heating and the radiation force due to electron scattering and spectral lines. To compute the radiation field, we consider an opti...