A steady-state flow model was used to optimize methods of data analysis, to investigate variables that affect the time-density curves, and to determine the accuracy of transit-flow measurements with digital subtraction angiography. The most accurate data were obtained by using a small region of interest placed within the vessel, averaged data acquisition, and a gamma-variate fit applied to the ...

Abstract. The flowing of powders brings a new challenging and interesting problem to the CFD community: at very high concentrations and low rate-of-strain, grains are in permanent contact, rolling on each other. Therefore a frictional stress model must be taken into account. This can be done using plasticity and similar theories in which the granular material behaviour is assumed to be independ...

Optimization of operation conditions (temperature, time, solvent: solid proportion) of subcritical water hydrolysis (SWH) is needed so that it can be considered an effective process for second generation bioethanol manufacturing. The objective of this study was to optimize operation conditions using a semi-batch SWH system equipped with a 50 mL reaction vessel. Initially, the process was carrie...

High concentrations of the ciliate Epidinium Crawley are associated with damaged regions of fresh plant material undergoing digestion in the sheep rumen. This finding supports that postulate that sequestration in the rumen explains the low rate of passage of protozoa despite the high flow rate of liquid from the rumen. The maintenance of Epidinium in the rumen, despite their slow growth rate, i...

Cerium dioxide, CeO2-δ, remains one of the most attractive materials under consideration for solar-driven thermochemical production of chemical fuels. Understanding the rate-limiting factors in fuel production is essential for maximizing the efficacy of the thermochemical process. The rate of response is measured here via electrical conductance relaxation methods using porous ceria structures w...

background: constructed wetlands (cw s ) are mimic filtration process in natural wetlands that effectively remove variety pollutants from wastewater. the main objective was the feasibility evaluation for using of subsurface flow constructed wetland in nitrogen and phosphorus removal from synthetic based on domestic wastewater in lab scale. methods: in this study, a synthetic wetland subsurface ...

The material accreting onto Sgr A* most probably comes from the nearby stars. We analyze the pattern of this flow at distances of a fraction of a parsec and we argue that the net angular momentum of this material is low but non-negligible, and the initially supersonic disk accretion changes into subsonic flow with constant angular momentum. Next we estimate the flow parameters at a distance RBH...