In the treatment of superficial lesions with 8-13 MeV electrons, lead shields are often used to protect the underlying tissue. Measurements were made with film and ion chamber to analyse various aspects of external and internal shielding in electron beam therapy. Data were obtained on the thickness of lead required for shielding, the effect of blocking on dose-rate, electron-backscattering from...

In this work we study the diamagnetic properties of a perfect quantum gas in the presence of a constant magnetic field of intensity B. We investigate the Gibbs semigroup associated to the one particle operator at finite volume, and study its Taylor series with respect to the field parameter ω := eB/c in different topologies. This allows us to prove the existence of the thermodynamic limit for t...

An approximate value of the diamagnetic anisotropy of the tubulin dimer, Δχ dimer, has been determined assuming axial symmetry and that only the α -helices and β -sheets contribute to the anisotropy. Two approaches have been utilized: (a) using the value for the Δχ α for an α -helical peptide bond given by Pauling (1979) and (b) using the previously determined anisotropy of fibrinogen as a cali...

2014 Superconducting shields offer the possibility of obtaining truly zero magnetic fields due to the phenomenon of flux quantization. They also offer excellent shielding from external time varying fields. Various techniques of superconducting shielding will be surveyed and recent results discussed. REVUE DE PHYSIQUE APPLIQUÉE: TOME 5, FÉVRIER 1970, PAGE

We have evaluated the NMR shielding tensors for A:T,G:C,A:U in Watson-crick, and U-quartet. We have computed NMR shielding tensors at B31YP level by using 6-31G(d) basis set. We have compute anisotropy and asymmetry in A:T,G:C,A:U and U-quartet. The NMR shielding tensors were calculated using the GIAO method. The natural bonding orbital analysis (NBO) were performed. NBO calculation have been ...

Numerical simulation of shielding effectiveness (SE) of a perforated shielding enclosure is carried out, using the finite element method (FEM). Possibilities of model definitions and differences between 2D and 3D models are discussed. An important part of any simulation is verification of the model results—here the simulation result are verified in terms of convergence of the model in dependenc...

Applications of liquid crystals (LCs), such as smart windows and the ubiquitous display devices, are based on controlling the orientational and translational order in a small volume of LC medium. Hence, understanding the effects of confinement to the liquid crystal phase behaviour is essential. The NMR shielding of (129)Xe atoms dissolved in LCs constitutes a very sensitive probe to the details...

A new thermoplastic material with extremely desirable physical and radiation shielding properties is presented. The material softens between 108 degrees F and 132 degrees F and can then be easily molded to any desired shape. As it cools down it hardens at about 102 degrees F, retaining its molded shape. It is very light (rho = 1.66 g/cc), compared to most other compensating and shielding materi...

Neoclassical shielding is the dominant mechanism reducing the collisionless zonal flow in a tokamak. Previously, this phenomenon was analyzed in the case of an essentially homogeneous equilibrium since the wavelength of the zonal flow perturbation was assumed to be much less than the scale length of background plasma parameters. This assumption is not appropriate in a tokamak pedestal. Therefor...