objective: the aim of this study is to evaluate the effect of tissue composition on dose distribution in electron beam radiotherapy. methods : a siemens primus linear accelerator and a phantom were simulated using mcnpx monte carlo code. in a homogeneous cylindrical phantom, six types of soft tissue and three types of tissue-equivalent materials were investigated. the tissues included muscle (s...

Computing the exact ideal and nadir criterion values is a very ‎important subject in ‎multi-‎objective linear programming (MOLP) ‎problems‎‎. In fact‎, ‎these values define the ideal and nadir points as lower and ‎upper bounds on the nondominated points‎. ‎Whereas determining the ‎ideal point is an easy work‎, ‎because it is equivalent to optimize a ‎convex function (linear function) over a con...

Linear stability analysis of the three dimensional plane wake flow is performed using a mapped finite di?erence scheme in a domain which is doubly infinite in the cross–stream direction of wake flow. The physical domain in cross–stream direction is mapped to the computational domain using a cotangent mapping of the form y = ?cot(??). The Squire transformation [2], proposed by Squire, is also us...

in this research work, the parameters affecting the settling velocity within the thickeners were studied by introducing an equivalent shape factor. several thickener feed samples of different densities including copper, lead and zinc, and coal were prepared. the settling tests were performed on the samples, and the corresponding settling curves were plotted. using the linear regression analysis...