introduction conventional water treatment consist of unit processes include coagulation, flocculation, clarification, filtration and disinfection that goal is removal of turbidity, color and certain bacterial species. in filtration process flocculated substances that have not removed in pervious stage are sediment. filter media is often silica sand that removal mechanism is complex and consists...

in this research, the effect of friction between the liquid metal and the sand mould wall and the effect of passage of liquid through a vertical bend and through a ceramic filter on the fluid flow and the melt velocity has been studied by measuring the velocity of the melt and direct observation of the liquid flow through the different parts of a naturally-pressurized running system. the fricti...

A low voltage square root domain filter based on the MOSFET square law is proposed. Through the verification of HSPICE simulation, the extendibility and the reliability of the design procedure are proven. A design technique for current-mode square-root domain band-pass filter simulation in a 0.18 μm CMOS process. The basic building block consists of current-mode current mirrors, square-root cir...

This study investigated the impacts of two best management practices (BMPs) recommended by US Environmental Protection Agency on Pb weathering and leachability in shooting range soils. The two BMPs included replacing soil berm with sand berm and periodically removing bullets or shot from a berm. A column experiment corresponding to the first BMP was conducted by mixing the bullets with sand/soi...

Abstract. An operator-splitting algorithm is presented for the solution of a partial differential equation arising in the modeling of deposition processes in sand mechanics. Sand piles evolution is modeled by an advection-diffusion equation, with a non-smooth diffusion operator that contains a point-wise constraint on the gradient of the solution. Piecewise linear finite elements are used for t...

The presence of microbial contaminants in urban stormwater is a significant concern for public health; however, their removal by traditional stormwater biofilters has been reported as inconsistent and inadequate. Recent work has explored the use of biochar to improve performance of stormwater biofilters under simplified conditions that do not consider potential effects of biofilm development on...

Abstract Hydraulic fracturing is an important technical means to improve the development effect of low-permeability oil and gas reservoirs. However, for low pressure, low-permeability, tight, high-clay sandstone reservoirs, conventional propped can cause serious damage reservoir restrict effect. The pre-acid technology combines acid treatment with sand-fracturing technology. A system that meets...

conventional sand filtration which has become a common wastewater treatment technology to satisfy regulations appointed for effluent reuse, suffers from the disadvantage of high energy for backwashing. the subject of this study is application of downflow floating media prior to coarse sand filtration, which requires less water for backwash. two pilots have been employed in two stages. for the f...

Many experimental studies demonstrate a match between the transfer function of sensory neurons and the statistics of natural stimuli. However, neurons might not be able to adapt to any given stimulus statistics due to very basic constraints. The high-pass nature of spike-frequency adaptation (Benda and Herz, 2003) emphasizes fast stimulus components over slow stimuli (Benda et al., 2005). The c...

Clusters of Microcalcifications which appear like small white grains of sand on Mammograms are the earliest signs of Breast Cancer. In this work we employ a Gabor filter bank for texture analysis of mammograms to detect microcalcifications. A subset of the Gabor filter bank with a certain central frequency and different orientations is used to obtain the Gabor-filtered images. The filtered imag...