2,832 research outputs found
Changes in union membership over time : a panel analysis for West Germany
Despite the apparent stability of the wage bargaining institutions in West Germany, aggregate union membership has been declining dramatically since the early 90's. However, aggregate gross membership numbers do not distinguish by employment status and it is impossible to disaggregate these sufficiently. This paper uses four waves of the German Socioeconomic Panel in 1985, 1989, 1993, and 1998 to perform a panel analysis of net union membership among employees. We estimate a correlated random effects probit model suggested in Chamberlain (1984) to take proper account of individual specfic effects. Our results suggest that at the individual level the propensity to be a union member has not changed considerably over time. Thus, the aggregate decline in membership is due to composition effects. We also use the estimates to predict net union density at the industry level based on the IAB employment subsample for the time period 1985 to 1997. JEL - Klassifikation: J
Quantum engineering of squeezed states for quantum communication and metrology
We report the experimental realization of squeezed quantum states of light,
tailored for new applications in quantum communication and metrology. Squeezed
states in a broad Fourier frequency band down to 1 Hz has been observed for the
first time. Nonclassical properties of light in such a low frequency band is
required for high efficiency quantum information storage in electromagnetically
induced transparency (EIT) media. The states observed also cover the frequency
band of ultra-high precision laser interferometers for gravitational wave
detection and can be used to reach the regime of quantum non-demolition
interferometry. And furthermore, they cover the frequencies of motions of
heavily macroscopic objects and might therefore support the attempts to observe
entanglement in our macroscopic world.Comment: 12 pages, 3 figure
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Intermixing at the InxSy/Cu2ZnSn(S,Se)4 Heterojunction and Its Impact on the Chemical and Electronic Interface Structure
We report on the chemical and electronic structure of the interface between a thermally co-evaporated InxSy buffer and a Cu2ZnSn(S,Se)4 (CZTSSe) absorber for thin-film solar cells. To date, such cells have achieved energy conversion efficiencies up to 8.6%. Using surface-sensitive X-ray and UV photoelectron spectroscopy, combined with inverse photoemission and bulk-sensitive soft X-ray emission spectroscopy, we find a complex character of the buffer layer. It includes oxygen, as well as selenium and copper that diffused from the absorber into the InxSy buffer, exhibits an electronic band gap of 2.50 ± 0.18 eV at the surface, and leads to a small cliff in the conduction band alignment at the InxSy/CZTSSe interface. After an efficiency-increasing annealing step at 180 °C in nitrogen atmosphere, additional selenium diffusion leads to a reduced band gap at the buffer layer surface (2.28 ± 0.18 eV)
Changes in Union Membership Over Time : A Panel Analysis for West Germany
Despite the apparent stability of the wage bargaining institutions in West Germany, aggregate union membership has been declining dramatically since the early 90's. However, aggregate gross membership numbers do not distinguish by employment status and it is impossible to disaggregate these su±ciently. This paper uses four waves of the German Socioeconomic Panel in 1985, 1989, 1993, and 1998 to perform a panel analysis of net union membership among employees. We estimate a correlated random effects probit model suggested in Chamberlain (1984) to take proper account of individual specific effects. Our results suggest that at the individual level the propensity to be a union member has not changed considerably over time. Thus, the aggregate decline in membership is due to composition effects. We also use the estimates to predict net union density at the industry level based on the IAB employment subsample for the time period 1985 to 1997
Test of Lorentz Symmetry by using a 3He/129Xe Co-Magnetometer
To test Lorentz symmetry we used a 3He/129Xe co-magnetometer. We will give a
short summary of our experimental setup and the results of our latest
measurements. We obtained preliminary results for the equatorial component of
the background field interacting with the spin of the bound neutron: b_n < 3.72
x 10^(-32) GeV (95 C.L.).Comment: Presented at the Fifth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 28 - July 2, 201
Limit on Lorentz and CPT violation of the bound Neutron Using a Free Precession 3He/129Xe co-magnetometer
We report on the search for Lorentz violating sidereal variations of the
frequency difference of co-located spin-species while the Earth and hence the
laboratory reference frame rotates with respect to a relic background field.
The co-magnetometer used is based on the detection of freely precessing nuclear
spins from polarized 3He and 129Xe gas samples using SQUIDs as low-noise
magnetic flux detectors. As result we can determine the limit for the
equatorial component of the background field interacting with the spin of the
bound neutron to be bn < 3.7 x 10^{-32} GeV (95 C.L.).Comment: 5 pages, 4 figure
Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura-families Chirostylidae, Galatheidae and Kiwaidae)
220 páginas, 5 figuras, 1 tabla.[EN] This adaptation text reproduces Anexo I of the dissertation “Results”: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el PacĂfico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771[ES] Este artĂculo es una adaptaciĂłn del Anexo I de la tesis doctoral: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el PacĂfico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771Taxonomic and ecological interest in squat lobsters has grown considerably over the last two decades. A checklist of the
870 current valid species of squat lobsters of the world (families Chirostylidae, Galatheidae and Kiwaidae) is presented.
The compilation includes the complete taxonomic synonymy and geographical distribution of each species plus type
information (type locality, repository and registration number). The numbers of described species in the world’s major
ocean basins are summarised.Peer reviewe
Keck-Nirspec Infrared OH Lines: Oxygen Abundances in Metal-Poor Stars Down to [Fe/H] = -2.9
Infrared OH lines at 1.5 - 1.7 um in the H band were obtained with the
NIRSPEC high-resolution spectrograph at the 10m Keck Telescope for a sample of
seven metal-poor stars. Detailed analyses have been carried out, based on
optical high-resolution data obtained with the FEROS spectrograph at ESO.
Stellar parameters were derived by adopting infrared flux method effective
temperatures, trigonometric and/or evolutionary gravities and metallicities
from FeII lines. We obtain that the sample stars with metallicities [Fe/H] <
-2.2 show a mean oxygen abundance [O/Fe] ~ 0.54, for a solar oxygen abundance
of epsilon(O) = 8.87, or [O/Fe] ~ 0.64 if epsilon(O) = 8.77 is assumed.Comment: To be published in ApJ 575 (August 10
Continuous variable polarization entanglement, experiment and analysis
We generate and characterise continuous variable polarization entanglement
between two optical beams. We first produce quadrature entanglement, and by
performing local operations we transform it into a polarization basis. We
extend two entanglement criteria, the inseparability criteria proposed by Duan
{\it et al.}\cite{Duan00} and the Einstein-Podolsky-Rosen paradox criteria
proposed by Reid and Drummond\cite{Reid88}, to Stokes operators; and use them
to charactise the entanglement. Our results for the Einstein-Podolsky-Rosen
paradox criteria are visualised in terms of uncertainty balls on the
Poincar\'{e} sphere. We demonstrate theoretically that using two quadrature
entangled pairs it is possible to entangle three orthogonal Stokes operators
between a pair of beams, although with a bound times more stringent
than for the quadrature entanglement.Comment: 12 pages, 13 figure
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