in this paper, electronic, structural, and spectroscopic properties of mono-, di-, tri-, andtetrafluorothiophenes and their radical cations are studied using the density functional theory andb3lyp method with 6-311++g** basis set. also the effects of the number and position of thesubstituent on the electrochemical properties of the thiophene ring have been studied usingoptimized structures obta...

effects of temperature and percentage of organic modifier were studied on retention and selectivity in rp-hplc using solvation parameter model. the system constants were determined by multiple linear regression analysis from experimental values in the retention factor for a group of different solutes with known descriptors by computer using the program spss/pc. the experimental results showed t...

Anisotropic dielectric response occurs naturally due to the presence of gradation, like in functionally graded materials or graded biological cells. However, these materials with locally anisotropic dielectric responses can have macroscopically isotropic responses. In treating graded particles of anisotropic materials, traditional isotropic gradation methods need to be modified. In this work, w...

The complex antenna factor (CAF) introduced to measure transient electromagnetic fields or electromagnetic pulses and its applications are investigated. The equations of the three-antenna method for determining the CAF of a dipole antenna, a log-periodic dipole array antenna (LPDA), and a monopole antenna are derived. The results of the waveform reconstructions using the CAF are compared with t...

In this paper a printed dipole antenna and three slot antennas are designed to operate at 10 GHz for use in radar systems. A parametric study of each antenna and comparison between their radiation properties including return loss, bandwidth, directivity, efficiency and radiation patterns for 6element linear array are introduced. Microstrip slot antennas show wider bandwidth, less coupling and s...

EEG is a noninvasive technique useful for the human brain mapping and for the estimation of neural electrical activities in human brain. A goal of processing EEG signals of a subject is the localization of neural current sources in human brain known as dipoles. Although this location estimation problem can be modeled as a particular kind of parameter estimation problem as in array signal proces...

enzymes catalyze many biological reactions. the rates of chemical reaction in the presence ofenzymes are, in some cases, accelerated more than 10 orders of magnitude relative to thecorresponding rates in solution.in this paper a comparison between optimized structures of two enzyme molecules in aspect ofenergy and dipole moment in different conditions including presence of metallic ion, without...

Various methods have been proposed to solve magnetoencephalographic inverse problems although the problem itself is ill-posed and in principle infinite number of solutions are possible. Among them, the simplest method is the single dipole in a spherical head model, which has been practically used in a lot of papers to get the dipoles activated by the sensory and cognitive tasks. However, if the...