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Open volume defects created by 1 MeV Fe+ implantation up to a damage of 15 displacements per atom into Fe14wt%Cr and into oxide dispersion strengthened (ODS) Fe14wt%Cr were investigated by positron annihilation spectroscopy, especially single Doppler broadening (DBS) and coincidence Doppler broadening spectroscopies (cDBS). The influence of W and Ti alloying elements on the evolution of defects during ion implantation were probed in addition. Whereas no effect of the W and Ti alloying constituents on the line-shape parameters S and W could be detected both before and after ion implantation, fine dispersed Y2O3 particles showed important changes in the structural properties compared to pure FeCr steel, which could be detected by DBS and cDBS. The distribution of the electron momenta in implanted ODS Fe14Cr, obtained with cDBS, shows that oxide particles form obstacles for expanded vacancy mobility and that the vacancies are localized around the oxide particles.

Abutilon theophrasti causes -severe yield losses in maize and soybean (70 % - 72%). A. theophrasti management is crucial for optimum crop production. Prevention is a pre-requisite to reduce weed pressure and investigation into weed bioecology is needed. This study characterized the morphological and genetic variation of eleven A. theophrasti accessions representative of a climatic gradient distribution range from north (47° N) to southeast Europe(39 ° N) and north America (43ºN). To evaluate interpopulation variability, seed were characterized with morphological parameters (length; width; thickness; weight and volume of 100 seeds) and biomolecular markers: trnL-trnF; trnH-trnK; trnT-psbC and matK. Multivariate and univariate analyses were performed to estimate genetic diversity within and among populations. Populations from north and southern Europe were separated in two groups according to seed morphology. However it was not possible to associate seed morphological traits to genetic variability. All gene sequences (cpDNA genome) presented the same nucleotide sequence

We report the first principle calculations of the lattice dynamics of KNi$_{2}$Se$_2$ together with the Raman scattering study.\ We have observed three out of four Raman active modes predicted by the factor group analysis. Calculated phonon frequencies are in good agreement with experimental findings.\ Contrary to its iron counterpart (K$_x$Fe$_{2-y}$Se$_2$), K$_{0.95}$Ni$_{1.86}$Se$_2$ does not show vacancy ordering.

Ultrafine porous cerium dioxide nanopowders were synthesized by relatively new and cost effective hydrothermal method varying the main synthesis parameters temperature of calcination and type of basic solution. Characterization of the as produced powders was performed by X ray diffraction (XRD) atomic force microscopy (AFM) Raman scattering and Brunauer Emmett Teller (BET) method. This study reveals that difference in synthesis parameters has strong influence on the particle size surface area and pore size distribution enabling the more precise control of material properties very important for catalytic and nanosensor applications. (C) 2011 WILEY VCH Verlag GmbH Co. KGaA Weinheim