Intrinsic energy resolution in γ-radiation detectors is limited by nonlinear quenching that varies as the second or third power of local excitation density. Using a numerical model for local light yield depending on measured quenching rates, kinetic order, and carrier mobilities, we employ Monte Carlo simulations of energy deposited at each local excitation density to calculate electron energy response that can be directly compared with Compton coincidence and K-dip experiments. Agreement is found for NaI:Tl and SrI2:Eu using thermalized carrier diffusion and linear quenched fraction deduced from total light yield. This lays the groundwork for testing refinements with recent hot-electron extensions of the model.

This paper shows a comparison between different nanostructured oxides, obtained by polymeric precursor method, regarding their activity for biodiesel conversion from oil–methanol mixtures. The basicity/acidity and surface area (SA) of the oxides were taken in account to analyze the catalytic activity in the transesterification reaction. The temperature dependence for the heterogeneous catalysts was analyzed, where only CaO showed activities at 70 °C (∼98% of conversion), while the other oxides, SnO2, ZnO, TiO2, CaTiO3, were observed active only at 150 °C for the reaction parameters adopted. The results revealed that the highest activity observed is not associated to SA only but mainly with the surface basicity. This suggest that, for oxides synthesized by the polymeric precursor method, the surface basicity surpasses the particle size effects in catalysis in a way to promote the transesterification reaction.

Gold nanoparticles (AuNPs) were biosynthesized using Bacillus megaterium, a common soil bacterium. Transmission electron microscopy images revealed that well-developed, spherical, homogeneous nanoparticles are formed extracellularly in reactions containing aqueous chloroaurate ions and conditioned medium at pH 4. Atomic force microscopy measurements showed that adhesion forces between biosynthesized AuNPs and breast cancer cells were almost six times greater than adhesion forces between biosynthesized AuNPs and normal breast cells. Furthermore, adhesion forces of biosynthesized AuNPs to breast cancer cells were three times greater than adhesion forces between chemically synthesized AuNPs and the same breast cancer cells. Finally, adhesion forces between biosynthesized AuNPs conjugated to breast-specific antibodies (AuNP-Ab conjugates), and breast cancer cells were almost five times greater than adhesion forces between unconjugated AuNPs and breast cancer cells. The implications of the results are discussed for the development of nanostructures for the targeted detection and treatment of breast cancer.

Quasicrystalline precipitates in ZrAlNiCuNb alloy were systematically studied by transmission electron microscopy. It was found that precipitates always contain various linear phason strains. By electron diffraction analysis, two types of linear phason strain with two different directions perpendicular to the incident beam described by strain matrices with only one nonzero element were identified. After measuring the deviations of diffraction spots and quantitatively fitting against their perpendicular components of the reciprocal lattice vectors, the phason strain matrices were obtained. Domain structures formed as a result of linear phason strain variants along directions with equal probability. Electron diffraction and high-resolution electron imaging provide supportive evidence of this result.

Comparisons of structural, optical, and magnetic properties between KY(WO4)2 (KYW) powders doped with Gd3+ from 0.5 up to 100 mol% and KGd(WO4)2and KYW single crystals have been made. For this purpose, x-ray diffraction (XRD), infrared (IR), Raman, and electron paramagnetic resonance (EPR) spectra were collected. The XRD studies have verified the quality of the synthesis of compounds and have shown the differences in the positions of the diffraction peaks due to the change in concentration of gadolinium ions. Raman and IR spectra confirmed that the phases are isostructural. The optimization of the spin Hamiltonian parameters and EPR data simulation was achieved by using the electron paramagnetic resonance and nuclear magnetic resonance (EPR-NMR) program. Changes in kind of magnetic interactions were found and analyzed from the point of view of their dependence of the compound form (powder, single crystal), temperature, and gadolinium ion concentration. The investigated compounds revealed complex interactions between gadolinium ions both in a type and a strength.

Carbothermal reduction of semiconducting TiO2 into highly conductive titanium oxycarbide (TiOxCy) was investigated. The thermally produced uniform carbon layer on TiO2 (Degussa P25) protects the TiO2 nanoparticles from sintering and, at the same time, supplies the carbon source for doping TiO2 with carbon. At low temperatures (e.g., 700 °C), carbon only substitutes part of the oxide and distorts the TiO2 lattice to form TiO2−xCx with only substitutional carbon. When the carbon-doped TiO2 is annealed at a higher temperature (1100 °C), x-ray diffraction and x-ray photoelectron spectroscopy results showed that TiOxCy, a solid solution of TiO and TiC, was formed, which displays different diffraction peaks and binding energies. It was shown that TiOxCy has much better oxygen revolution reaction activity than TiO2 or TiO2−xCx. Further studies showed that the TiOxCyobtained can be used as a support for metal electrocatalyst, leading to a bifunctional catalyst effective for both oxygen reduction and evolution reactions.