introduction lead-based shields are the most widely used attenuators in x-ray and gamma ray fields. the heavy weight, toxicity and corrosion of lead have led researchers towards the development of non-lead shields. materials and methods the purpose of this study was to design multi-layered shields for protection against x-rays and gamma rays in diagnostic radiology and nuclear medicine. in this...

in the present study, a comprehensive and systematic strategy was described to evaluate the performance of several three-way calibration methods on a bio-analytical problem. parallel factor analysis (parafac), alternating trilinear decomposition (atld), self-weighted alternating trilinear decomposition (swatld), alternating penalty trilinear decomposition (aptld) and unfolded partial least squa...

gas compressibility factor (z-factor) is an important parameter widely applied in petroleum and chemical engineering. experimental measurements, equations of state (eoss) and empirical correlations are the most common sources in z-factor calculations. however, these methods have serious limitations such as being time-consuming as well as those from a computational point of view, like instabilit...

objective(s):multi-epitopic protein vaccines and direction of vaccine delivery to dendritic cells (dcs) are promising approaches for enhancing immune responses against mutable pathogens. escherichia coli is current host for expression of recombinant proteins, and it is important to optimize expression condition. the aim of this study was the optimization of multi-epitopic hiv-1 tat/pol/gag/env ...

background: the frequency of the multi-drug resistance 1 (mdr1) gene c3435t polymorphism differs in various ethnical populations such as asian, african, and caucasians populations. a silent c3435t polymorphism in exon 26 of mdr1 has been reported to be associated with a decreased expression of p-gp in tt genotypes carriers compared with cc genotypes carriers. materials and methods: to evaluate ...

in this paper we propose a relatively new semi-analytical technique to approximate the solution ofnonlinear multi-order fractional differential equations (fdes). we present some results concerning to the uniqueness of solution of nonlinear multi-order fdes and discuss the existence of solution for nonlinear multi-order fdes in reproducing kernel hilbert space (rkhs). we further give an error an...

multi agent markov decision processes (mmdps), as the generalization of markov decision processes to the multi agent case, have long been used for modeling multi agent system and are used as a suitable framework for multi agent reinforcement learning. in this paper, a generalized learning automata based algorithm for finding optimal policies in mmdp is proposed. in the proposed algorithm, mmdp ...

modelling and forecasting stock market is a challenging task for economists and engineers since it has a dynamic structure and nonlinear characteristic. this nonlinearity affects the efficiency of the price characteristics. using an artificial neural network (ann) is a proper way to model this nonlinearity and it has been used successfully in one-step-ahead and multi-step-ahead prediction of di...

data envelopment analysis (dea) is a method for measuring the efficiency of peer decision making units (dmus) with multiple inputs and outputs. the traditional dea treats decision making units under evaluation as black boxes and calculates their efficiencies with first inputs and last outputs. this carries the notion of missing some intermediate measures in the process of changing the inputs to...

gamma-rays emitted from the ground surface relate to the primary mineralogy and geochemistryof the bedrock, and the secondary weathered materials. this information can contribute significantly to anunderstanding of the geochemical and pedogenetic history of a region. the main aim of this paper was to study the relationship between ground gamma-ray data and basement geochemistry in the lese catc...