Background: Monte Carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. Advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the MCNB4B Monte Carlo code. The simulations were carried out for the three common neutron sources, namely the 252Cf, the 241Am/Be and the DD neutron generator w...

Background: Several landmine detection methods, based on nuclear techniques, have been suggested up to now. Neutron-induced gamma emission, neutron and gamma attenuation, and fast neutron backscattering are the nuclear methods used for landmine detection. In this paper an optimized (safe and effective) moderating structure using an 241Am-Be neutron source for detecting landmines has been invest...

Neutron dose-equivalent buildup factors were calculated for point isotropic neutron sources irradiating infinite slablike shields of lead, iron and water using the MCNP code. The factors are presented for some source neutron energies in the range from 0.025 eV to 14 MeV, and for shield thicknesses from 0.5 to 10 mfp. Since the MCNP code considers all kinds of neutron interactions with matter, a...

introduction bnct is an effective method to destroy brain tumoral cells while sparing the healthy tissues. the recommended flux for epithermal neutrons is 109 n/cm2s, which has the most effectiveness on deep-seated tumors. in this paper, it is indicated that using d-t neutron source and optimizing of beam shaping assembly (bsa) leads to treating brain tumors in a reasonable time where all iaea ...

conclusions in hbeag positive chb patients, low serum hbsag level is a useful predictor of compensated cirrhosis. objectives the aim of our study was to evaluate serum hbsag level as a biomarker for compensated cirrhosis in hepatitis b e antigen (hbeag) positive chb patients. patients and methods two-hundred and one hbeag-positive chinese chb patients with or without cirrhosis were enrolled in ...

A study of the correlations between the stoichiometry, secondary phases and transition metal ordering of LiNi(0.5)Mn(1.5)O(4) was undertaken by characterizing samples synthesized at different temperatures. Insight into the composition of the samples was obtained by electron microscopy, neutron diffraction and X-ray absorption spectroscopy. In turn, analysis of cationic ordering was performed by...

Porosity is a key parameter on thermal barrier coatings, directly influencing conductivity and strain tolerance. Suspension high velocity oxy-fuel (SHVOF) spraying enables the use of sub-micron particles as feedstock, increasing control over porosity introducing nano-sized pores; these fine-scale porosities being challenging to measure. Neutron scattering represents non-destructive technique, c...