3,849 research outputs found
CMB anisotropies in the presence of a stochastic magnetic field
Primordial magnetic fields present since before the epoch of matter-radiation
equality have an effect on the anisotropies of the cosmic microwave background.
The CMB anisotropies due to scalar perturbations are calculated in the gauge
invariant formalism for magnetized adiabatic initial conditions. Furthermore
the linear matter power spectrum is calculated. Numerical solutions are
complemented by a qualitative analysis.Comment: 26 pages, 21 figures; sections 2 and 4 expanded; matches version
published in PR
Research into the scintillation behaviour of a few fast organic plastic and fluid scintillators
The Slowdown in Productivity Growth: Analysis of Some Contributing factors
macroeconomics,product growth
Electronic transport properties through thiophenes on switchable domains
The electronic transport of electrons and holes through stacks of
,\ome ga-dicyano-,'-dibutyl- quaterthiophene (DCNDBQT)
as part of a nov el organic ferroic field-effect transistor (OFFET) is
investigated. The novel ap plication of a ferroelectric instead of a dielectric
substrate provides the poss ibility to switch bit-wise the ferroelectric
domains and to employ the polarizat ion of these domains as a gate field in an
organic semiconductor. A device conta ining very thin DCNDBQT films of around
20 nm thickness is intended to be suitab le for logical as well as optical
applications. We investigate the device proper ties with the help of a
phenomenological model called multilayer organic light-e mitting diodes
(MOLED), which was extended to transverse fields. The results sho wed, that
space charge and image charge effects play a crucial role in these org anic
devices
Cavity Reactor Engineering Mockup Critical Experiment
Critical mass of uranium 235 for stainless steel lined cavities in nuclear research and test reactors with heavy water reflecto
The Defenseless Marriage Act: The Constitutionality of the Defense of Marriage Act as an Extension of Congressional Power under the Full Faith and Credit Clause
The Defenseless Marriage Act: The Constitutionality of the Defense of Marriage Act as an Extension of Congressional Power under the Full Faith and Credit Clause
Effect of Drying on Grain Quality -- Moisture Readsorption Causes Fissured Rice Grains
Among others, drying can affect the quality of rice or other cereal grains (with a hard vitreous endosperm) in three prevalent and distinctive ways. These are:1. Through Moisture Readsorption by Dry Rice Grains: Rice, as well as other cereal grains, is hygroscopic. The low-moisture (dried) grain readsorbs moisture from any source to which it is exposed. Moisture adsorbed through the grain surface causes the starch cells to expand and produce compressive stresses. Since the grain is a "free body", compressive stresses are countered by equal but opposite tensile stresses at the grain centre. When the compressive stresses at the surface exceed the tensile strength of the grain at its centre, a fissure develops. Fissured grains usually break during milling. Sources for grain moisture readsorption are discussed.2. Through Moisture Readsorption by Field Rice Grains: When rice grains in the field reach harvest moisture (22%), the field sample may contain grains with moisture contents (MC) between 15 and 45%. Many individual grains may dry to below 15% MC during the day. Such grains can fissure on the stalk when they readsorb moisture at night.3. Through Rapid Drying (To near storage moisture): Rapid drying produces a steep moisture gradient in the grain. As this gradient reclines after drying, the grain surface receives moisture from the interior and expands while the grain interior loses moisture and contracts. As this combination of stresses (compressive at the surface and tensile at the centre) develops with time, the grain fails in tension by pulling itself apart at its centre. The rheological aspects (stress, strain and time) that cause the grain failure are discussed.Most breakage in rice processing can be attributed to grains which were fissured before milling. Moisture readsorption by low-moisture grains in the field before harvest is the most prevalent cause of fissured grains. Mechanical harvesting at a higher moisture content can minimize this type of grain failure. -- Fissuring of the rice grain after drying can be controlled by the drying procedure. Rapid drying which leaves a steep moisture gradient in the grain at the end of drying will cause the grain to fissure after drying. With time the grain fails in tension. Rice drying should not be terminated with a steep moisture gradient in the grain
Life-cycle patterns in male/female differences in job search
We investigate whether women search longer for a job than men and whether these
differences change over the life cycle. Our empirical analysis exploits German
register data on highly attached displaced workers. We apply duration models to
analyze gender differences in job search taking into account observed and unobserved
worker heterogeneity and censoring. Simple survival functions show that displaced
women take longer to find a new job than comparable men. Disaggregation by age
groups reveals that these differences are driven by differential behavior of prime age
women. There is no significant difference in job search duration among the very
young and older workers. These differential outcomes remain even after we control
for differences in human capital, and when time dependence and unobserved
heterogeneity are incorporated into the model
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