Introduction: The role of radiotherapy as a part of cancer management increases every year around the world. Thus, Radiation protection in the design of radiotherapy rooms are of great importance.   Materials and Methods: In present study using Monte Carlo method, MCNPX code, fourteen types of developed high density concretes with densities ranging from 2.45 ...

Geometrical structure, nuclear magnetic resonance (N1,1It) chemical shielding tensors, and chemical shiftsof silicon and carbon nucler are investigated for twn infinite size zigzag and armchair single-walled siliconcarbide nanotabes (SiCNTs). Geometrical structures of SieNTs, Sit bonds and bond angles of St and Cvertices in both zigzag and armchair nanotubes, Indicate that bond lengths are appr...

In this research, the Magnetite nanoparticles (Fe304) were prepared by coprecipitation of Fe- andGinger is a well known spice and flavoring agent which has also been used in traditional medicine inmany countries. Ginger contains essential oils including gingerol and zingiberene. It also containspungent principles such as zingerone, and shogaol. In the paper six theoretical methods were used toc...

Recent theoretical developments permit the prediction of 1H, 13C, 15N, and 19F nuclear magnetic resonance chemical shifts in proteins and offer new ways of analyzing secondary and tertiary structure as well as for probing protein electrostatics. For 13C, phi, psi torsion angles dominate shielding for C alpha and C beta, but the addition of hydrogen bonding and electrostatics gives even better a...

The chemical shielding is the most familiar and universal parameter in the field of nuclear magnetic resonance (NMR). It may be calculated or measured experimentally; it may be studied by gas phase, liquid phase, or solid phase NMR, as well as by quantum mechanical methods. This chapter will introduce NMR both from a theoretical and an experimental standpoint, and quantum theory. The following ...

The effect of rotation and vibration on the nuclear magnetic resonance ~NMR! shielding constants was computed for HF, F2, N2, CO, and HBr. The shielding constants for H, C, N, O, and F nuclei were calculated using sum-over-states density functional perturbation theory ~SOS-DFPT!. Diatomic ro-vibrational states were calculated from a discrete variable representation using Morse potentials and po...

J. Matusiak, J. Wyciślik, Institute of Welding, Gliwice, Poland The article presents the results of research into the fume and gas emission during MIG/MAG arc weld brazing. Investigations were conducted for hot dip coated steel sheets with zinc and zinc and iron alloy coatings. Steel grades of DX 54D Z 100 MBO and DX 54D ZF 100 RBO were used during research. ARC shielding gases applied were Ar ...

We compute the magnetic shielding tensor within the London approximation and estimate the Knight shift of single-wall carbon nanotubes. Our results indicate that high resolution 13C NMR should be able to separate the metallic and insulator character of the nanotubes since a 11 ppm splitting is predicted from the respective resonances. As a model for disorder, bending, and defects in these struc...

The change in (1)H NMR chemical shifts upon hydrogen bonding was investigated using both experimental and theoretical methods. The (1)H NMR spectra of a number of phenols were recorded in CDCl(3) and DMSO solvents. For phenol, 2- and 4-cyanophenol and 2-nitrophenol the OH chemical shifts were measured as a function of concentration in CDCl(3). The plots were all linear with concentration, the g...

DSHIFT is a web server for predicting chemical shifts of DNA sequences in random coil form or double helical B-form. The prediction methods are based on sets of published reference chemical shift values and correction factors which account for shielding or deshielding effects from neighboring nucleotides. Proton, carbon and phosphorus chemical shift predictions are available for random coil DNA...