In open channels, the relationship between the specific energy and the flow depth exhibits a minimum, and the corresponding flow conditions are called critical flow conditions. Herein they are reanalyzed on the basis of the depth-averaged Bernoulli equation. At critical flow, there is only one possible flow depth, and a new analytical expression of that characteristic depth is developed for ide...

BACKGROUND AND PURPOSE Established methods of ultrasonic perfusion imaging using a bolus application of echo contrast agent provide only qualitative data because of various physical phenomena. This study was intended to investigate whether a new ultrasound perfusion imaging method termed contrast burst depletion imaging (CODIM) may provide semiquantitative measures of parenchymal perfusion inde...

Abstract A split-by-edges tree of a graph G is a binary tree T where the root = V(G), every leaf is an independent set in G, and for every other node N in T with children L and R there is an edge uv in G such that u and v are in N, L = N – v and R = N – u. Every maximum independent set in G is in the same layer M, which is guarantied to be found in a layer by layer search of T. Every depth-firs...

In this paper, dry etching of silicon micro-trenches were completed with a time multiplexed inductively coupled plasma (ICP) etcher. By change the time of etching and passivation cycles, applied electrode and coil powers, gas flow rates and the gas flow overlap due to the finite time response of the mass flow controllers, the etch rate of silicon and mask materials, aspect ratio, the profiles o...

Experiments on oscillating flow at the abrupt transition between a two-dimensional channel and essentially infinite space are presented. It is shown that phenomena associated with the transition are functions of three independent dimensionless parameters including the dimensionless radius rounding the edge of the end of the channel. The effect of each of these three parameters on the time-avera...

lemon is one of the most important citrus fruit and is consumed as fresh and dry. in this study the effect of fruit moisture content on the size, sphericity, geometric mean diameters and kernel density were studied. the bulk density and porosity were also evaluated in three different arrangements. airflow resistance is a fundamental parameter for designing an efficient drying and aeration syste...

shock formation due to flow compressibility and its interaction with boundary layer has inappropriate effects, such as drag increase and flow separation. many methods have been proposed for reduction of these effects, such as vortex generator, suction, and blowing. this paper numerically studies the problem of flow control for naca0012 airfoil with porous media at transonic flow. porous media, ...