Search results for "SSB"
showing 10 items of 537 documents
Synchrotron Mössbauer Reflectometry in Materials Science
1999
57Fe nuclear resonant scattering experiments are reported on iron-containing thin films using 14.41 keV synchrotron radiation at angles of grazing incidence around and slightly above the critical angle of the electronic total reflection. In partially oxidised α–Fe films of 20 nm original thickness various oxide and oxihydroxide phases are identified at different depth. In a [Fe/FeSi]10multilayer grown on Zerodur®substrate the Fe—Fe interlayer coupling varies with the distance from the substrate. The antiferromagnetic order of the top layers of this multilayer can be suppressed by external magnetic field. These examples demonstrate the efficiency of synchrotron Mossbauer reflectometry (SMR),…
“Building Integrated Photovoltaics and DSSC-Glassblocks"
2012
According to many market analysts, Building Integrated Photovoltaics (BIPV) represents the future of photovoltaic (PV) industry as well as one of the strategies for the achievement of zero-energy building standards and UE goals for the next years. Dye-sensitised solar cell (DSSC) is a low-cost and very versatile solar technology, offering a wide range of possibilities in terms of colour, transparency and design: hence DSSC are particularly suited for BIPV and could give a big contribution in this direction. Starting from those considerations, this paper will show the first results of a research aimed at the integration of DSSC with the glassblock for the construction of multifunctional tran…
Studies on some antimony(III) complexes with tridentate schiff base ligands
1981
Abstract The antimony(III) complexes FSb(Sab), ClSb(Sab) and ClSb(Sat) containing dianonic, potentially tridentate Schiff-base ligands with ONO(Sab 2− ) and ONS(Sat 2− ) donor atoms have been prepared and characterized. The mass spectra of these derivatives are reported. The occurrence of chelation by the tridentate ligand is inferred from the infrared data. The antimony-121 Mossbauer parameters at 4.2 K are reported. The magnitudes and the positive sign of eQV zz suggest a consistent p-character of the antimony lone-pair orbital. Observed differencies in the isomer shift and eQV zz values are discussed on the basis of the likely distribution of electron density around antimony.
A Global Climatology of Tropical Moisture Exports
2013
Abstract In a recent paper, a climatology of tropical moisture exports (TMEs) to the Northern Hemisphere (NH) was constructed on the basis of 7-day forward trajectories, started daily from the tropical lower troposphere, which were required to reach a water vapor flux of at least 100 g kg−1 m s−1 somewhere north of 35°N. It was shown that TMEs contribute significantly to regional precipitation. Here, the authors complement and extend this work by (i) using 6-hourly European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) data from 1979 to 2010 instead of the earlier 40-yr ECMWF Re-Analysis (ERA-40), (ii) extending the climatology to the Southern Hemispher…
Identifying Rossby wave trains and quantifying their properties
2013
A novel method is introduced to automatically identify upper-level Rossby wave trains and to objectively diagnose their properties. Based on the envelope of the upper tropospheric meridional wind represented in a Hovmoller diagram, the algorithm identifies individual Rossby wave trains as objects. These depend to some extent on user defined parameters. The utility of the method is demonstrated in two areas of application. First, the skill of a particular numerical weather prediction model is analysed for a specific case of a long-lived Rossby wave train. For this purpose, a novel diagnostic is designed based on a Hovmoller diagram of the Rossby wave train objects that contains forecast data…
Long-lived Rossby wave trains as precursors to strong winter cyclones over Europe
2013
The statistical connection between strong surface cyclones over Europe and long-lived upper-tropospheric Rossby wave trains is examined for the Northern Hemisphere winter season using 45 years of reanalysis data. Dates are selected for which the surface pressure anomaly over Central Europe is below a threshold yielding the 5% of lowest values. Composites of upper tropospheric meridional wind for these dates (including a lead or lag in time) display clear signs of a wave train. The composite wave train lives for over two weeks and propagates eastward over more than 360° longitude. The phase speed of individual lows and highs, by contrast, is close to zero and the same is true for the composi…
La teoría de las emociones de Martha Nussbaum: el papel de las emociones en la vida pública
2014
Los objetivos de la presente tesis consisten en: 1) examinar los marcos teóricos desde los que se ha intentado explicar la naturaleza de las emociones, prestando especial atención al marco propuesto por Nussbaum; 2) poner a prueba la propuesta cognitiva-evaluativa de la autora; 3) examinar el contenido cognitivo de las emociones que la autora ha estudiado y ver qué papel desempeñan en la vida pública. The objectives of this thesis are: 1) to examine the theoretical frameworks from which scholars have attempted to explain the nature of emotions, paying special attention to Nussbaum's framework; 2) to test the author's cognitive-evaluative proposal; 3) to examine the cognitive content of the …
Electron trapping centres and cross sections in LiNbO3studied by57Co Mössbauer emission spectroscopy
1999
Fast electron trapping processes and aliovalent charge states following the 57Co(EC)57Fe decay are studied in undoped, 5.4 mol% Mg-doped and 0.1 mol% Fe-doped LiNbO3 in various thermochemical reduction (TCR) states. Static 57Co Mossbauer emission spectra of congruent Mg:LiNbO3 recorded at T = 4.2 K in external magnetic field of 4.6 T are presented. Trapping cross section ratios are derived for Fe3+Li, Nb5+Li and Mg2+Li. A method to determine trap concentrations for TCR states of LiNbO3 is outlined. The electron-capture distance of the traps is found to be 2.7±1.4 nm. As this is much smaller than the 6 keV Auger-electron penetration depth, it is concluded that the distribution of the alioval…
Structural and magnetic properties of the solid solution series Sr2Fe1–xMxReO6(M = Cr, Zn)
2005
Strong correlations between the electronic, structural and magnetic properties have been found during the study of doped double perovskites Sr2Fe1−xMxReO6 (0 ≤ x ≤ 1, M = Zn, Cr). The interplay between the van Hove singularity and the Fermi level plays a crucial role for the magnetic properties. Cr doping of the parent compound Sr2FeReO6 leads to a non-monotonic behaviour of the saturation magnetization and an enhancement for doping levels up to 10%. The Curie temperatures monotonically increase from 401 to 616 K. In contrast, Zn doping leads to a continuous decrease in the saturation magnetization and the Curie temperatures. Superimposed on the electronic effects is the structural influenc…
Mossbauer study on the distribution of iron in high coercivity chromium dioxide particles
1992
/sup 57/Fe Mossbauer spectroscopy is applied to determine the level of iron doping in high-coercivity CrO/sub 2/ particles. It is found that, compared with the conventional preparation process, the particles contain an increased amount of Fe/sup 3+/ ions in the CrO/sub 2/ crystal lattice, giving rise to higher magnetocrystalline anisotropy. This is reflected in coercivities up to over 900 Oe. All samples contain as a secondary iron-containing phase some (Cr/sub 1-x/Fe/sub x/)/sub 2/O/sub 3/. The valence of the iron doping is predominantly +3; very weak signals in the Mossbauer spectra suggest the existence of Fe/sup 4+/ in an amount 2-3% of the total number of iron atoms. >