Radiation shielding analysis and design calculations were performed for remote maintenance cells of the proposed National Spallation Neutron Source (NSNS) facility. In the analysis, a calculational strategy utilizing coupled high energy Monte Carlo calculations and multidimensional discrete ordinates calculations was implemented to perform an activation analysis and shielding assessment of the ...

Density functional theory methods(DFT) and natural bond orbital (NBO) analysis were used to investigate the effects of isomerism and side chain mutation at a microscopic level on the stability, binding energy and NMR/NQR tensors of structural isomers, L- methionylasparagine (Met-Asn) and L- asparagylmethionine (Asn-Met) in the gas phase. The results represented that the isomerism and side chain...

We report optimized design of multilayered electromagnetic shield using real coded genetic algorithm. It is observed that the shielding effectiveness in multilayer design is higher than single layered counterpart of equal thickness. An effort has been made to develop an alternative approach to achieve specific objective of identifying the design characteristics of each layer in the multilayered...

Radiation shielding requirements for fusion reactors present different problems than those for fission reactors and accelerators. Fusion devices, particularly tokamak reactors, are complicated by geometry constraints that complicate disposition of fully effective shielding. This paper reviews some of these shielding issues and suggested solutions for optimizing the machine and biological shield...

INTRODUCTION In radiation therapy centers across Iran, protection of normal tissues is usually accomplished by either Cerrobend or lead block shielding. In this study, the influence of these two shielding methods on central axis dose distribution of photon beam a Cobalt unit was investigated in clinical conditions. MATERIALS AND METHODS All measurements were performed for 60Co γ-ray beams and...

OBJECTIVES This study sought to determine the efficacy of patient pelvic lead shielding for the reduction of operator radiation exposure during cardiac catheterization via the radial access in comparison with the femoral access. BACKGROUND Cardiac catheterization via the radial access is associated with significantly increased radiation dose to the patient and the operator. Improvements in ra...

An analysis is made of the charge distribution in a quasi-static thundercloud system with the assumptions that (1) the cloud has a charge separation mechanism at its midpoint and ( 2 ) the conductivity within the cloud is reduced by a given fraction from the free-air conductivity remote from the storm. The charge separation mechanism produces the primary positive dipole of the storm. The analys...

PURPOSE High-radiation exposure occurs during computed tomographic (CT) fluoroscopy. Patient and operator doses during thoracic and abdominal interventional procedures were studied in the present experiment, and a novel shielding device to reduce exposure to the patient and operator was evaluated. MATERIALS AND METHODS With a 16-slice CT scanner in CT fluoroscopy mode (120 kVp, 30 mA), surfac...

Cationic polymers are promising components of the versatile platform of non-viral nucleic acid (NA) delivery agents. For a successful gene delivery system, these NA vehicles need to comprise several functionalities. This work focuses on the modification of oligoaminoamide carriers with hydrophilic oligomer blocks mediating nanoparticle shielding potential, which is necessary to prevent aggregat...