15,978 research outputs found
Ion-retarding lens improves the abundance sensitivity of tandem mass spectrometers
Ion-retarding lens which increases the abundance sensitivity of tandem magnetic-analyzer mass spectrometers measures isotopes of low abundance in mass positions adjacent to isotopes of high abundance. The lens increases the abundance sensitivity for isotopes lying farther from high abundance isotopes than the energy cutoff of the lens
Multilevel Governance and Women's Legislative Representation
Research shows that electoral systems, gender quotas and a country's socio-economic development affect women's legislative representation (WLR). Less attention is paid to the effects of the rise of regional political arenas and multilevel politics on WLR. Due to less costly and competitive electoral campaigns, women can have easier access to regional legislatures. We argue that this relationship is mitigated by the distribution of competences between the different levels of the political system and that decentralization's effect on WLR at the regional level is dependent on the regions’ political power. To test this, we use an original dataset on WLR in 383 regional parliaments in 19 European countries from 1970 to 2018. Results of the three-level models show that more political authority vested into regions leads to a lower level of WLR in the legislatures of the more politically powerful regions in comparison with not only the regions possessing less authority but also with the national parliament. Possible explanations for this effect, such as the attractiveness of these positions to the mostly male political elite and, consequently, increased costs and competitiveness of electoral campaigns, are suggested.Introduction Multilevel governance and women's political representation Data Analysis Conclusion Acknowledgements Supporting information Reference
Recovery of the Shape of the Mass Power Spectrum from the Lyman-alpha Forest
We propose a method for recovering the shape of the mass power spectrum on
large scales from the transmission fluctuations of the Lyman-alpha forest,
which takes into account directly redshift-space distortions. The procedure, in
discretized form, involves the inversion of a triangular matrix which projects
the mass power spectrum in 3-D real-space to the transmission power spectrum in
1-D redshift-space. We illustrate the method by performing a linear calculation
relating the two. A method that does not take into account redshift-space
anisotropy tends to underestimate the steepness of the mass power spectrum, in
the case of linear distortions. The issue of the effective bias-factor for the
linear distortion kernel is discussed.Comment: 18 pages, 4 figures; minor revision
Exact calculation of three-body contact interaction to second order
For a system of fermions with a three-body contact interaction the
second-order contributions to the energy per particle are
calculated exactly. The three-particle scattering amplitude in the medium is
derived in closed analytical form from the corresponding two-loop rescattering
diagram. We compare the (genuine) second-order three-body contribution to with the second-order term due to the density-dependent
effective two-body interaction, and find that the latter term dominates. The
results of the present study are of interest for nuclear many-body calculations
where chiral three-nucleon forces are treated beyond leading order via a
density-dependent effective two-body interaction.Comment: 9 pages, 6 figures, to be published in European Journal
Non-Minimal Inflation after WMAP3
The Wilkinson Microwave Anisotropy Probe (WMAP) three year results are used
to constraint non-minimal inflation models. Two different non-minimally coupled
scalar field potentials are considered to calculate corresponding slow-roll
parameters of non-minimal inflation. The results of numerical analysis of
parameter space are compared with WMAP3 data to find appropriate new
constraints on the values of the non-minimal coupling. A detailed comparison of
our results with previous studies reveals the present status of the non-minimal
inflation model after WMAP3.Comment: 16 pages, 11 figures, 2 tables, Revised Versio
Monolithic Arrays of Grating-Surface-Emitting Diode Lasers and Quantum Well Modulators for Optical Communications
The electro-optic switching properties of injection-coupled coherent 2-D grating-surface-emitting laser arrays with multiple gain sections and quantum well active layers are discussed and demonstrated. Within such an array of injection-coupled grating-surface-emitting lasers, a single gain section can be operated as intra-cavity saturable loss element that can modulate the output of the entire array. Experimental results demonstrate efficient sub-nanosecond switching of high power grading-surface-emitting laser arrays by using only one gain section as an intra-cavity loss modulator
gamma Doradus pulsation in two pre-main sequence stars discovered by CoRoT
Pulsations in pre-main sequence stars have been discovered several times
within the last years. But nearly all of these pulsators are of delta
Scuti-type. gamma Doradus-type pulsation in young stars has been predicted by
theory, but lack observational evidence. We present the investigation of
variability caused by rotation and (gammaDoradus-type) pulsation in two
pre-main sequence members of the young open cluster NGC2264 using
high-precision time series photometry from the CoRoT satellite and dedicated
high-resolution spectroscopy. Time series photometry of NGC2264VAS20 and NGC
2264VAS87 was obtained by the CoRoT satellite during the dedicated short run
SRa01 in March 2008. NGC2264VAS87 was re-observed by CoRoT during the short run
SRa05 in December 2011 and January 2012. Frequency analysis was conducted using
Period04 and SigSpec. The spectral analysis was performed using equivalent
widths and spectral synthesis. The frequency analysis yielded 10 and 14
intrinsic frequencies for NGC2264VAS20 and NGC2264VAS 87, respectively, in the
range from 0 to 1.5c/d which are attributed to be caused by a combination of
rotation and pulsation. The effective temperatures were derived to be
6380150K for NGC2264VAS20 and 6220150K for NGC2264VAS87. Membership
of the two stars to the cluster is confirmed independently using X-ray fluxes,
radial velocity measurements and proper motions available in the literature.
The derived Li abundances of log n(Li)=3.34 and 3.54 for NGC2264VAS20 and
NGC2264VAS87, respectively, are in agreement with the Li abundance for other
stars in NGC2264 of similar Teff reported in the literature. We conclude that
the two objects are members of NGC2264 and therefore are in their pre-main
sequence evolutionary stage. Assuming that part of their variability is caused
by pulsation, these two stars might be the first pre-main sequence gamma
Doradus candidates.Comment: 11 pages, 10 figures, A&A accepte
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