abstractl density functional theory (dft) was used to investigate the effects of intra-moecular interactions and implicit water molecules on the relative stability and the nmr shielding tensors of hallucinogenic harmine in the monomeric and dimeric states. results represented that the relative stability and the nmr shielding tensors are dependent on the resonance interactions and chemical envir...

background: high density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. over the past eight years, some efficient galena-based concrete samples for shielding x or gamma rays was produced. the goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. materials an...

to minimize renal radiation in abdomical radiotherapy, shielding of the kidneys is essential. ivp-simulator is used as an standard method. in this study, we used 99mtc-dmsa to localize and shield the kidneys and we compared this method with ivp-simulator. the size of the kidneys was proven to be larger as compared with ivp method. the mean of the overlap percentage was 81.88 in right and 82.89 ...

background the use of shielding tools and x-ray beam collimator has extensively been advocated as effective methods to reduce radiation exposure to patients underwent radiological procedures. the aim of this study was to address the use of these protection measures during infant chest radiography. material and methods 348digital and/or analogue infant chest radiographs were reviewed that perfor...

background: in radiation therapy, the sparing of normal tissues can be performed using either multi-leaf collimators or cerrobend blocks. the current work focuses on the physical characteristics of cerrobend blocks including attenuation coefficient, effective penumbra width and isodose curves undulation in penumbral regions. materials and methods: all measurements were performed using a dual en...

the physical and chemical properties of pyrazole and pyrazoline molecules were theoreticallystudied by gaussian 03, software with nmr and molecular orbital calculations at b3lyp/6-31g andb3lyp/6-31+g(d) levels, in gas phase and solution. in this study a comparison effect of threesolvents with different dielectric constants on pyrazole and pyrazoline molecules in aspect energyinteraction between...

To clarify the correspondence between Shielding Effectiveness (SE) of shielding materials and their physical property, we propose an equivalent circuit for a shielding effectiveness test apparatus using a dual TEM cell, and show its validity. By considering the structure of dual TEM cell that consists of a pair of cells coupled via an aperture in their common wall, we defined the capacitance C ...

Sunset solar axions traversing the intense magnetic field of the CERN Axion Solar Telescope (CAST) experiment may be detected in a Time Projection Chamber (TPC) detector, as point-like X-rays signals. These signals could be masked, however, by the inhomogeneous background of materials in the experimental site. A detailed analysis, based on the detector characteristics, the background radiation ...