background: in neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials.   objective: the purpose of this study is to evaluate dose distribution in the presence of  10 b ,  157 gd  and  33 s  ne...

Background: Prompt gamma neutron activation analysis (PGNAA) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. Also it is a valuable diagnostic tool for total body elemental measurements. 252Cf and 241Am-Be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

background: the aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or pmma), a150 plastic and te- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. materials and methods: thermal neutron fluence, photon dose and epithermal neut...

Terahertz (THz) absorption and neutron vibrational spectra for solid-phase short-chain peptide sequences at 77 and 298 K are reported. We demonstrate that a high degree of spectral and structural information exists for these systems in the 1–15 THz (33–500 cm ) spectral range. The density and uniqueness of distinct spectral features for each system suggests that sequence-dependent structural in...

The combined local structure techniques, extended x-ray absorption fine structure and neutron pair distribution function analysis, have been used for temperatures 4< or =T< or =330 K to rule out a large Jahn-Teller (JT) distortion of the Co-O bond in La1-xSrxCoO3 for a significant fraction of Co sites (x< or =0.35), indicating few, if any, JT-active, singly occupied e_{g} Co sites exist.

The apparent partial specific volume, phi, of a protein (or other macromolecule) and the absolute concentration, c, can be determined from the densimetry of solutions and diffusates in 1H2O , 2H2O and 1H2O/2H2O mixtures if the ratios of concentrations (relative concentrations) are known. The densimetry method allows a non-destructive check on total macromolecule concentrations without prior kno...

Recent infrared and neutron scattering data provide evidence for strong electron-phonon coupling in the 52 meV/420 cm-’ range in YBa&u,O,. From a simple model of two coupled oscillators it is shown that a linear electron-phonon coupling can give the observed antiresonance structure in the frequency-dependent conductivity. We argue that the coupling is to the bound carriers responsible for the m...

The fl decay of the neutron-deficient isotope l°3In was investigated by using total absorption y-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the fl-decay strength in striking disagreement with high-resolution y-ray data. The result is discussed in comparison with shell-model predictions. @ 1998 Elsevier Science B.V. PACS: 21.10.-k; 21.60.Cs; 23....

Recent probing of H2O-D2O mixtures by various means (neutron deep inelastic scattering, Raman absorption, electrical H/D conductivity) revealed an unexpected dependence of the relevant physical quantities on the isotopic composition of the mixture. We show that these observations can find their physical rationale in the context of an approach to the physics of liquid water which takes into acco...