abstract in order to investigate the removal of copper, nickel, zinc and chromium from industrial waste water by a sand–soil–organic matter filter column, this experiment was conducted at a completely randomized design with sixteen treatments and four replications. p.v.c tubes (columns) with 66.5 cm height and 10 cm diameter were chosen and filled from down to top by coarse gravel (15 cm), sand...

In this paper, a modified auto zeroed integrator is used to design and simulate a low-voltage high-Q switched capacitor pseudo 2-path filter.  The filter is a sixth–order Chebyshev band-pass filter operating at sampling frequency of 1MHz and center frequency of 250 kHz with a quality factor of 50. The proposed filter has both low-voltage and high speed properties of the auto zeroed integrators ...

In this paper, a novel technique for the design of two-channel Quadrature Mirror Filter (QMF) banks with linear phase in frequency domain is presented. To satisfy the exact reconstruction condition of the filter bank, low-pass prototype filter response in pass-band, transition band and stop band is optimized using unconstrained indirect update optimization method. The objective function is form...

one of the common problems in reflection seismic records in the land is the existence of surface waves with high amplitude and low frequency which cause the most important parts of reflective signals to be masked. therefore, it is necessary to attenuate them by processing and acquisition methods. as it is impossible to attenuate the surface waves completely, and sometimes it is likely to damage...

background: hemodialysis is a process of removing waste and excess fluid from blood when kidneys cannot function efficiently. it often involves diverting blood to the filter of the dialysis machin to be cleared of toxic substances. fouling of pores in dialysis membrane caused by adhesion of plasma protein and other toxins will reduce the efficacy of the filtre. objective: in this study, the inf...

introduction: one of the main complications of hemodialysis in patients with chronic renal failure is hypoxemia which is related to several factors including the type of filter. the aim of this study was to evaluate the hypoxemia levels in patients undergoing hemodialysis with focus on the type of filter. methods: in a crossover clinical trial, 29 patients from emodialysis ward of fatemieh hosp...

background the first commercial system for digital radiography was introduced in 1987, and it has evolved a great deal since then. currently, it is possible to enhance images in digital radiography. objectives the aim of this study is to evaluate the diagnostic accuracy of image enhancement in direct digital radiography as it relates to interproximal carries assessment. conclusions using these ...