This paper presents a novel microstrip low-pass filter with good performance. A complete detailed theoretical analysis for the proposed filter is given using equivalent circuit models. The proposed filter applying multiple cascaded modified radial stubs resonators provides a sharp cut off frequency response that has a 185 dB/GHz roll off rate. Also, U-shaped attenuators provide a wide stop-band...

soil water potential was determined for three soil samples (i.e. 0-30, 30-60 and 60-90 cm depth) by the filter paper method (hamblin, 1981) and also for four non-destructive soil samples (i.e. 0-30, 30-50, 50-75 and 75-90 cm horizon) using pressure plate method.  in filter paper method, the filter paper is placed in hydraulic contact with the soil until an equilibrium state is attained in which...

E valuating a virus filter should, in theory, be a straightforward exercise. Membrane-based filtration is a robust virus-reduction technology that plays an important role in virus safety for most drug production processes. An appropriate virus filter for a given process is generally selected through preliminary testing with relevant drug feed material. Data acquired during such tests are used t...

an air filter is a significant element of any mechanical ventilation system. however, the importance and performance evaluation of air filters have not been well publicized and related scientific reports are scarce. in this study, a transportable, off-line, air filter-testing unit (the unit) was designed and utilized to simulate the filter housing of a mechanical ventilation system. the unit wa...

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...

Heparin surface coated hemofilters and tubing sets were evaluated in comparison to identical but uncoated controls in 8 bovine experiments (74+/-6 kg). No heparin was given (neither systemically nor in the priming fluid). The hemofilters were primed with one liter of Ringer's lactate in both groups and the maximal filter performance (arterial line pressure 300 mmHg; transmembrane pressure (TM...

A simple idea of the frequency transformation where each delay of the original real lowpass filter transfer function is replaced by the same allpass filter allows a lot of flexibility in manipulating the original filter to fit the required specification. The simple cases of real first-order transformations and a very few second-order ones have been suggested by Constantinides in the early 1970s...