27,205 research outputs found
Employment, wage structure, and the economic cycle: differences between immigrants and natives in Germany and the UK
Differences in the cyclical pattern of employment and wages of immigrants relative
to natives have largely gone unnoticed in the migration literature. In this paper we
show that immigrants and natives react differently to the economic cycle. Based on
over two decades of micro data, our investigation is for two of the largest immigrant
receiving countries in Europe which at the same time are characterised by different
immigrant populations as well as different economic cycles, Germany and the UK.
Understanding the magnitude, nature and possible causes of differences in
responses is relevant for assessing the economic performance of immigrant
communities over time. We show that there are substantial differences in cyclical
responses between immigrants and natives. Our analysis illustrates the magnitude of
these differences, while distinguishing between different groups of immigrants.
Differences in responses may be due to differences in the skill distribution between
immigrant groups and natives, or differences in demand for immigrants and natives
of the same skills due to differential allocation of immigrants and natives across
industries and regions. We demonstrate that substantial differences in cyclical
patterns remain, even within narrowly defined groups. Finally, we estimate a more
structural factor type model that, using regional variation in economic conditions,
separates responses to economic shocks from a secular trend and allows us to
obtain a summary measure for these differences within education groups
Tool pre-tensions covers prior to lacing
In securing a bulky object in a storage compartment, a cinching or tightening tool is used to draw two opposing cover halves together at a predetermined tension to permit quick lacing to retain the stored object. This tool is also useful in fabrication industries to draw components together during assembly or treating
2H and 13C NMR studies on the temperature-dependent water and protein dynamics in hydrated elastin, myoglobin and collagen
2H NMR spin-lattice relaxation and line-shape analyses are performed to study
the temperature-dependent dynamics of water in the hydration shells of
myoglobin, elastin, and collagen
Effective Operators for Double-Beta Decay
We use a solvable model to examine double-beta decay, focusing on the
neutrinoless mode. After examining the ways in which the neutrino propagator
affects the corresponding matrix element, we address the problem of finite
model-space size in shell-model calculations by projecting our exact wave
functions onto a smaller subspace. We then test both traditional and more
recent prescriptions for constructing effective operators in small model
spaces, concluding that the usual treatment of double-beta-decay operators in
realistic calculations is unable to fully account for the neglected parts of
the model space. We also test the quality of the Quasiparticle Random Phase
Approximation and examine a recent proposal within that framework to use
two-neutrino decay to fix parameters in the Hamiltonian. The procedure
eliminates the dependence of neutrinoless decay on some unfixed parameters and
reduces the dependence on model-space size, though it doesn't eliminate the
latter completely.Comment: 10 pages, 8 figure
Spatially heterogeneous dynamics and dynamic facilitation in a model of viscous silica
Performing molecular dynamics simulations, we find that the structural
relaxation dynamics of viscous silica, the prototype of a strong glass former,
are spatially heterogeneous and cannot be understood as a statistical bond
breaking process. Further, we show that high particle mobility predominantly
propagates continuously through the melt, supporting the concept of dynamic
facilitation emphasized in recent theoretical work.Comment: 4 pages, 4 figure
Production of radioactive isotopes through cosmic muon spallation in KamLAND
Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in ν detectors, double-β-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of ^(11)C. Data from the Kamioka liquid-scintillator antineutrino detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillators, and for checking estimates from current simulations based upon MUSIC, FLUKA, and GEANT4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be Y_n=(2.8±0.3)×10^(-4) μ^(-1) g^(-1) cm^2. For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment
Measurement of neutrino oscillation with KamLAND: Evidence of spectral distortion
We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 v_e candidate events with energies above 3.4 MeV compared to 365.2±23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8±7.3 expected background events, the statistical significance for reactor v_e over bar (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from v_e oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Δm^2=7.9_(-0.5)^(+0.6)x10^(-5) eV^2. A global analysis of data from KamLAND and solar-neutrino experiments yields
Δm^2=7.9_(-0.5)^(+0.6)x10^(-5) eV^2 and tan^2θ=0.40_(-0.07)^(+0.10), the most precise determination to date
Leaky cavities with unwanted noise
A phenomenological approach is developed that allows one to completely
describe the effects of unwanted noise, such as the noise associated with
absorption and scattering, in high-Q cavities. This noise is modeled by a block
of beam splitters and an additional input-output port. The replacement schemes
enable us to formulate appropriate quantum Langevin equations and input-output
relations. It is demonstrated that unwanted noise renders it possible to
combine a cavity input mode and the intracavity mode in a nonmonochromatic
output mode. Possible applications to unbalanced and cascaded homodyning of the
intracavity mode are discussed and the advantages of the latter method are
shown.Comment: 13 pages, 7 figures; published versio
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