Myocardial perfusion SPECT imaging with Tc99m-sestamibi is the most accurate non-invasive means of detecting coronary artery disease and assessing the severity of perfusion abnormalities in the patients with coronary stenosis. Though simple and straight forward the results produced by the technique is very much affected by the details being used. One of the main problems with the test, wh...

Background: In CT systems, the machine utilizes a bowtie filter to shape the X-ray beam and remove lower energy photons. The shape of this bowtie filter is complicated and its geometry is often not available in detail. These renders the CT dose index (CTDI) to have different values in measurement versus Monte Carlo simulation studies and other analytical calculations especially in dosimetry of ...

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...

In this paper, a new voltage controlled first order all-pass filter is presented. The proposed circuit employs a single differential voltage dual-X second generation current conveyor (DV-DXCCII) and a grounded capacitor only. The proposed all-pass filter provides both inverting and non inverting voltage-mode outputs from the same configuration simultaneously without any matching condition. Non-...

Filter is one of the main components of embankment dams. By a simple but effective performance, filter protects the dam against erosion and soil scouring in impervious core caused by leakage (piping) and makes it safe. Interaction between filter and erodible base soil is a complex phenomenon which is dependent upon several factors, and has challenged researchers for better understanding the fil...

in the several past years, extended kalman filter (ekf) and unscented kalman filter (ukf) havebecame basic algorithm for state-variables and parameters estimation of discrete nonlinear systems.the ukf has consistently outperformed for estimation. sometimes least estimation error doesn't yieldwith ukf for the most nonlinear systems. in this paper, we use a new approach for a two variablesta...

here, we propose an optical filter and an optical power splitter based on two-dimensionalphotonic crystal all circular ring resonators. these structures are made of a square lattice ofsilicon rods with the refractive index n1=3.464 surrounded by air (with refractive indexn2=1). first, we have designed the filter and by using that, we designed a power splitter. thetransmission efficiency and qua...