Gamma irradiation induced preparation of poly(acrylamide–itaconic acid)/zirconium hydrous oxide for removal of Cs-134 radionuclide and methylene blue

Adsorption experiments were carried out to investigate the removal of Cs-134 radionuclide and methylene blue (MB) from aqueous solution using poly(acrylamide–itaconic acid)/N,N′-methelyenediacrylamide/zirconium hydrous oxide composite [poly(AM–IA)/DAM/Zr(OH)₄] as an adsorbent. The effects of initial pH value, initial concentration of Cs or MB, adsorbent dose, contact time and temperature on adsorption were investigated. Characterization of the prepared composite was carried out using FT-IR, XRD, TGA, DTA, and SEM. The adsorption behaviors showed that the adsorption kinetics and isotherms were in good agreement with the pseudo-second-order and the Langmuir models indicating the chemosorption mechanism. Thermodynamic studies were carried out and it was found that the process was spontaneous exothermic in nature. Discussion of the results of the adsorption behavior showed that the prepared composite can be used as a promising adsorbent for removal of Cs-134 or MB.     

Comparison of radiation detector performance for different metal contacts on CdZnTe deposited by electroless deposition method

A comparative study of four different metals gold (Au), platinum (Pt), ruthenium (Ru) and rhodium (Rh) deposited on CdZnTe(CZT) by the electroless deposition method has been carried out. Two of these materials, Ru and Rh, have been deposited for the first time by this method. In contrast to the Pt deposition, the deposition of Ru and Rh were not carried out under the optimal conditions. The metals deposited on the samples were identified by Total reflection X‐ray Fluorescence (TXRF). Rutherford Backscattering Spectrometry (RBS) analyses show that Au forms the thickest layer (∼160 nm) for the experimental conditions of this work. Current‐voltage measurements show that Pt forms a more linear ohmic contact with the lowest leakage current. A ⁵⁷Co gamma ray spectrum gave a better detector performance with a FWHM 11 keV at 122 keV. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

1-motivic sheaves and the Albanese functor

Using sheaf theoretic methods, we define functors and . The functor extends the one in [L. Barbieri-Viale, B. Kahn, On the derived category of 1-motives, I. Prépublication Mathématique de l’IHÉS (M/07/22), June 2007, 144 pages] to non-necessarily geometric motives. These functors are then used to define higher Néron-Severi groups and higher Albanese sheaves.     

Catalytic dehydrogenation of natural terpenes via CuPd alloy nanoparticles generated on mesoporous graphitic carbon nitride

A facile wet-chemical protocol for the synthesis of bimetallic CuPd alloy nanoparticles (NPs) anchored on mesoporous graphitic carbon nitride (m-gCN), serving as both stabilizer and support material, was presented herein. The presented protocol allowed to synthesize nearly monodisperse CuPd alloy NPs with an average particle size of 3.9 ± 0.9 nm without use of any additional surfactants and to prepare CuPd/m-gCN nanocatalysts with different Cu/Pd compositions (Cu₂₅Pd₇₅/m-gCN, Cu₃₅Pd₆₅/m-gCN, Cu₁₆Pd₇₄/m-gCN, Cu₃₂Pd₆₈/m-gCN, Cu₁₀Pd₉₀/m-gCN, and Cu₅₀Pd₅₀/m-gCN). After the detailed characterization of CuPd/m-gCN nanocatalysts, they were utilized as catalysts in the dehydrogenation of terpenes. Among all tested nanocatalysts, Cu₅₀Pd₅₀/m-gCN showed the highest activity in terms of the product yields within the same reaction time. Various parameters influencing the catalytic activity of Cu₅₀Pd₅₀/m-gCN were studied using himachalene as a model substrate and the optimum conditions were determined. Under the optimized reaction conditions, the catalytic application of Cu₅₀Pd₅₀/m-gCN nanocatalysts was extended to nine different terpenes and the corresponding products were obtained in high conversion yields (>90%) under mild conditions. A reusability test showed that Cu₅₀Pd₅₀/m-gCN nanocatalysts can be re-used up to four cycles without significant loss in their initial activity.