A comprehensive review on radioactive waste cycle from generation to disposal

Journal of Radioanalytical and Nuclear Chemistry - Radioactive wastes are the byproduct of nuclear technology and industrial processes. Unlike any other waste stream, radioactive wastes are...     

Poly(4-vinylpyridine) catalyzed chemoselective O-TMS protection of alcohols and phenols and N-Boc protection of amines

Poly(4-vinylpyridine) (PVP) acts as an efficient and reusable catalyst for the selective and efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) and N-tert-butoxycarbonylation of amines with (Boc)₂O. All reactions were performed under mild conditions in good to high yields.     

Magnetic and magnetization properties of electrodeposited fcc CoPt nanowire arrays

Magnetic and magnetization properties of fcc Co_1−xPt_x (x?0.3) alloy nanowires fabricated by electrodeposition into self-synthesized anodic alumina templates are investigated. Magnetization curves, measured for varying wire geometries, show a crossover of easy axis of magnetization from parallel to perpendicular to the nanowire axis as a function of the diameter and length. The measured values of coercivity (H_c) and remanent squareness (SQ) of CoPt nanowire arrays, as a function of angle (θ) between the field and wire axis, support the crossover of easy axis of magnetization. The curling mode of the magnetization reversal process is observed for CoPt nanowire arrays. At low temperatures, the easy axis for magnetization of the nanowires is observed to deviate from the room-temperature orientation.     

Selective Monoarylation of Primary Amines Using the Pd‐PEPPSI‐IPentCl Precatalyst

A single set of reaction conditions for the palladium‐catalyzed amination of a wide variety of (hetero)aryl halides using primary alkyl amines has been developed. By combining the exceptionally high reactivity of the Pd‐PEPPSI‐IPent^Cl catalyst (PEPPSI=pyridine enhanced precatalyst preparation, stabilization, and initiation) with the soluble and nonaggressive sodium salt of BHT (BHT=2,6‐di‐tert‐butyl‐hydroxytoluene), both six‐ and five‐membered (hetero)aryl halides undergo efficient and selective amination.     

Infrared lattice vibrations in CuGe2P3

Infrared reflectivity spectra of CuGe₂P₃ single crystals are measured at room temperature in the wavenumber range from 180 to 4000 cm⁻¹. From an analysis of the spectra the parameters of five vibrational modes are determined. The results are discussed in terms of the Keating model and are compared with lattice vibrational data for ZnGeP₂, CdGeP₂, and CuSi₂P₃.     

Infrared optical properties and crystal structure of Cu2GeS3

Infrared reflectivity and transmission spectra of Cu₂GeS₃ are measured at room temperature in the wavenumber range from 180 to 4000 cm⁻¹. From an analysis of the spectra the parameters of the fundamental infrared active lattice modes and of the two-phonon combination modes are determined. From a comparison of the experimental data with group theoretical predictions for the structure models proposed for Cu₂GeS₃ in the literature it is concluded that Cu₂GeS₃ crystallizes in a monoclinic lattice.     

Numerical optimisation of process parameters for combined quasi-static and impulse forming

Mathematical optimisation of technological forming processes requires expensive simulations to evaluate objective function and constraint values as well as their derivative and Hessian informations. Therefore numerical linearisation methods like the finite difference method or the BFGS-update are necessary. In this work the effects of these approximation techniques are studied. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Infrared optical properties of (CuGe2P3)1−x(6 Ge)x solid solutions

Infrared reflectivity spectra of (CuGe₂P₃)_1−x(6 Ge)_x mixed crystals with compositions in the range x = 0.07–0.33 are measured at room temperature in the wavenumber range from 180 to 4000 cm⁻¹. An analysis of the spectra reveals six vibrational modes. The composition dependence of the mode frequencies and of the free carrier concentration and mobility is given and compared with infrared optical data for CuGe₂P₃.