19,307 research outputs found
Influence of Lifshitz transitions and correlation effects on the scattering rates of the charge carriers in iron-based superconductors
Minimum model calculations on the co-action of hole vanishing Lifshitz
transitions and correlation effects in ferropnictides are presented. The
calculations predict non-Fermi-liquid behaviour and huge mass enhancements of
the charge carriers at the Fermi level. The findings are compared with recent
ARPES experiments and with measurements of transport and thermal properties of
ferropnictides. The results from the calculation can be also applied to other
unconventional superconductors and question the traditional view of quantum
critical points.Comment: 6 pages, 6 figure
Effects of long-term farmyard manure applications on soil organic matter, nitrogen mineralization and crop yield – a modeling study –
To develop sustainable cropping systems we need to predict both short-term and long-term effects of management practices on soil fertility. For this purpose agro-ecosystem simulation models are valuable tools. We used the Daisy model to simulate a three-year crop rotation (beetroot, onion, white clover, potato) over a period of 40 years. With this rotation, three rates of farmyard manure were tested (0, 15, 28 t ha-1 year-1). After 40 years without manure soil organic matter carbon (SOM-C) decreased by approximately 40%, and increased by 27% with the highest application rate. SOM turnover did not reach equilibrium at the end of the experiment. Nitrogen mineralization from SOM followed in the long-term (40 years) the slowly changing time courses of SOM. However, manure applications affected mineralization and hence crop yield and nitrogen losses much more in the short-term (1 to 2 years) than in the long-term
A little beyond tomorrow
The present and long range benefits of space technology to man and his world are discussed. Data cover communications, education, earth resources, health, transportation, and manufacture of products in space
Resonant Elastic Soft X-Ray Scattering
Resonant (elastic) soft x-ray scattering (RSXS) offers a unique element,
site, and valence specific probe to study spatial modulations of charge, spin,
and orbital degrees of freedom in solids on the nanoscopic length scale. It
cannot only be used to investigate single crystalline materials. This method
also enables to examine electronic ordering phenomena in thin films and to zoom
into electronic properties emerging at buried interfaces in artificial
heterostructures. During the last 20 years, this technique, which combines
x-ray scattering with x-ray absorption spectroscopy, has developed into a
powerful probe to study electronic ordering phenomena in complex materials and
furthermore delivers important information on the electronic structure of
condensed matter. This review provides an introduction to the technique, covers
the progress in experimental equipment, and gives a survey on recent RSXS
studies of ordering in correlated electron systems and at interfaces
Bus voltage compensation circuit for controlling direct current motor
Automatic control of voltage supply to direct current moto
Measurement of the Proteinase Inhibitors of the Bovine Pancreas by Radioimmunoassay
Bovine pancreas contains two polypeptide trypsin inhibitors that are not homologous and differ in their inhibitory activity towards chymotrypsin, kallikrein, elastase, and other serine proteinases. The Kunitz inhibitor and the Kazal inhibitor are present in approximately equimolar concentrations in bovine pancreatic tissue, yet only the Kazal inhibitor is detectable in the pancreatic juice. The Kazal inhibitor has been named the pancreatic secretory trypsin inhibitor, PSTI because its concentration in the pancreatic juice parallels that of the exocrine secretory proteins. The Kunitz inhibitor is considered the intracellular inhibitor, however, no direct information is available concerning the intracellular localization of these inhibitors in the pancreas. The preparation of /sup 125/I-labeled derivatives of Kazal and Kunitz inhibitors by the lactoperoxidase method and a radioimmunoassay for each inhibitor are described
Stationary phase slip state in quasi-one-dimensional rings
The nonuniform superconducting state in a ring in which the order parameter
vanishing at one point is studied. This state is characterized by a jump of the
phase by at the point where the order parameter becomes zero. In uniform
rings such a state is a saddle-point state and consequently unstable. However,
for non-uniform rings with e.g. variations of geometrical or physical
parameters or with attached wires this state can be stabilized and may be
realized experimentally.Comment: 6 pages, 7 figures, RevTex 4.0 styl
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