background:  radiochromic film is used for radiation dose measurement, xr-rv3 is used in fluoroscopy and ebt2 film in radiation therapy. the aim was to determine if the dosimetric properties of these two films are comparable in megavolt photon beams. materials and methods: comparison measurements included: calibration curves, heterogeneous phantom dose profiles, and nasopharynx dose distributio...

‎Here‎, ‎we give a two phases algorithm based on integrating differential evolution (DE) algorithm with modified hybrid genetic algorithm (MHGA) for solving the associated nonlinear programming problem of a nonlinear optimal control problem‎. ‎In the first phase‎, ‎DE starts with a completely random initial population where each individual‎, ‎or solution‎...

there is a great interest in developing rapid analytical methods and provide appropriate parametersfor quantitative analysis of compounds derived from refractory pollutants. such methods are important forroutine quality control analysis of an effluent before being discharged into the environment. therefore, a rapid methodology for identification and quantification of some aliphatic acids is pro...

in this study, porous scaffolds from poly(d,l-lactic acid) have been prepared via liquid- liquid phase separation method in ternary system of polymer-1,4-dioxane-water. polymer dissolved in dioxane in 1.5, 2.5 and 5 % wt/v and the solvent/non-solvent ratios were 13/87, 15/85 and 17/83. cloud point curves prepared by visual turbidometry. in order to obtain porous scaffolds with inter-connected p...

in this study, a manganite sample with a nominal formula of la0.9sr0.1mno3 was prepared by the microwave assisted sol-gel method and annealing at various temperatures. the structural and magnetic properties of the samples were investigated by xrd, fesem and ac susceptometer, respectively. xrd analysis showed that the samples are a nearly single phase. fesem micrographs showed that by increasing...

Neural-network dynamics frequently organize in assemblies of synchronized neurons that are thought to encode and store sensory information. We have investigated the mechanisms leading to the emergence of these neural assemblies with models of coupled oscillators. In particular, we used experimentally estimated phase-resetting curves (PRC) of real neurons (mitral cells) to realistically describe...

Type I membrane oscillators such as the Connor model (Connor et al. 1977) and the Morris-Lecar model (Morris and Lecar 1981) admit very low frequency oscillations near the critical applied current. Hansel et al. (1995) have numerically shown that synchrony is difficult to achieve with these models and that the phase resetting curve is strictly positive. We use singular perturbation methods and ...

Phase reduction is an invaluable technique for investigating the dynamics of nonlinear limit cycle oscillators. Central to the implementation of phase reduction is the ability to calculate phase response curves (PRCs), which describe an oscillator's response to an external perturbation. Current experimental techniques for inferring PRCs require data from individual oscillators, which can be imp...

The Kepler mission has allowed the detection of numerous multi-planet exosystems where the planetary orbits are relatively compact. The first such system detected was Kepler-11 which has six known planets at the present time. These kinds of systems offer unique opportunities to study constraints on planetary albedos by taking advantage of both the precision timing and photometry provided by Kep...

the main purpose of this investigation is to study the effect of near miscible co2 injection in different porous mediums on both lab and field scales. this effect can be traced by the change of two-phase gas-oil relative permeability curves. in this work, the experiments have been performed on three rock types (i.e. sandstone, dolomite, and artificial fractured sandstone) based on an incrementa...