Search results for "RECESS"
showing 10 items of 379 documents
Effects of Raising Minimum Wage: Theory, Evidence and Future Challenges
2013
Abstract Minimum wage is one of the most studied topics in economics. This paper examines some of the most important issues related to the effects of raising minimum wage, based on new contributions in theoretical and empirical research, roughly since 2008. Our purpose was to find in the literature an explanation for the recent raise of minimum wage, in some European Union countries and United States and to identify possible effects of this evolution. Most of the studies point little or no employment response to modest increases in the minimum wage, but we argue there are some other effects to consider.
A Note on Palaeolithic Soundscapes. Further Thoughts on the LMT (Landscape Mind Theory)
2010
Homo sapiens sapies' mind possesses a cognitive module specifically for landscape that spatially organizes perceptions, representations and individual and collective knowledge. This module also acts in the conceptual and symbolic organization of sounds.
Optimal control of the inversion of two spins in Nuclear Magnetic Resonance
2012
International audience; We investigate the optimal control of the inversion of two spin 1/2 particles in Nuclear Magnetic Resonance. The two spins, which differ by their resonance offset, are controlled by the same radio frequency magnetic field. Using the Pontryagin Maximum Principle, we compute the optimal control sequence which allows to reach the target state in a given time, while minimizing the energy of the magnetic field. A comparison with the time-optimal solution for bounded control amplitude realizing the same control in the same time is made. An experimental illustration is done using techniques of Nuclear Magnetic Resonance.
Measurement of the Permanent Electric Dipole Moment of the $^{129}$Xe Atom
2019
We report on a measurement of the $CP$-violating permanent electric dipole moment (EDM) of the neutral $^{129}\mathrm{Xe}$ atom. Our experimental approach is based on the detection of the free precession of co-located nuclear spin-polarized $^{3}\mathrm{He}$ and $^{129}\mathrm{Xe}$ samples. The EDM measurement sensitivity benefits strongly from long spin coherence times of several hours achieved in diluted gases and homogeneous weak magnetic fields of about 400 nT. A finite EDM is indicated by a change in the precession frequency, as an electric field is periodically reversed with respect to the magnetic guiding field. Our result $(\ensuremath{-}4.7\ifmmode\pm\else\textpm\fi{}6.4)\ifmmode\t…
Probing Lorentz invariance and other fundamental symmetries in3He/129Xe clock-comparison experiments
2011
We discuss the design and performance of a very sensitive low-field magnetometer based on the detection of free spin precession of gaseous, nuclear polarized 3He or 129Xe samples with a SQUID as magnetic flux detector. Characteristic spin precession times T*2 of up to 60 h were measured in low magnetic fields (about 1μT) and in the regime of motional narrowing. With the detection of the free precession of co-located 3He/129Xe nuclear spins (clock comparison), the device can be used as ultra-sensitive probe for non-magnetic spin interactions, since the magnetic dipole interaction (Zeeman-term) drops out in the weighted frequency difference, i.e., Δω = ωHe− γHe/γXe·ωXe. We report on searches …
Spin dynamics in the single-ion magnet [Er(W5O18)2]9−
2018
In this work we present a detailed NMR and ${\ensuremath{\mu}}^{+}\mathrm{SR}$ investigation of the spin dynamics in the new hydrated sodium salt containing the single-ion magnet ${[\mathrm{Er}{({\mathrm{W}}_{5}{\mathrm{O}}_{18})}_{2}]}^{9\ensuremath{-}}$. The $^{1}\mathrm{H}\phantom{\rule{0.16em}{0ex}}\mathrm{NMR}$ absorption spectra at various applied magnetic fields present a line broadening on decreasing temperature which indicates a progressive spin freezing of the single-molecule magnetic moments. The onset of quasistatic local magnetic fields, due to spin freezing, is observed also in the muon relaxation curves at low temperature. Both techniques yield a local field distribution of t…
Anomalous Muon Knight Shift Behavior in a Cd Single Crystal
1983
For the positive muon implanted in a metal the precession frequency shift due to hyperfine fields can be measured with high precision. This provides means to obtain information about the local electronic structure of a hydrogen like impurity in any metal in the indefinitely dilute impurity concentration. Ref. 1 gives a summary of the muon Knight shift (KS) investigations in 18 nontransition (simple) metals and some transition metals and discusses the results in the context of the electronic structure of hydrogen in metals.
Search for Spin-Dependent Short-Range Interaction with an 3He/129Xe Clock Comparison Experiment
2016
We performed an experiment to search for a new spin-dependent P- and T-violating nucleon–nucleon interaction [Formula: see text] which is mediated by light pseudoscalar bosons such as axions or axionlike particles. This interaction causes a shift [Formula: see text] in the precession frequency of nuclear spin polarized gases in the presence of an unpolarized mass. In order to measure this frequency shift a 3He/[Formula: see text]Xe comagnetometer was used which is based on the detection of free precession of 3He and [Formula: see text]Xe nuclear spins using SQUIDs as detectors. For the upper limit of [Formula: see text] we obtained 7.1[Formula: see text]nHz. With this value, an upper limit…
Measurement of the g Factor of the Bound Electron in Hydrogen-like Oxygen 16O7+
2003
The measurement of the g factor of the electron bound in a hydrogen-like ion is a high- accuracy test of the theory of Quantum Electrodynamics (QED) in strong fields. Here we report on the measurement of the g factor of the bound electron in hydrogen-like oxygen 16O7+. In our experiment a single 16O7+ ion is stored in a Penning trap. Quantum jumps between the two spin states (spin up and spin down) are induced by a microwave field at the spin precession frequency of the bound electron. The g factor of the bound electron is obtained by varying the microwave frequency and counting the number of spin flips. Our experimental value for the g factor of the bound electron is gexp(16O7+) = 2.000 04…
Traducción y género: el estado de la cuestión en España
2011
Todo proceso experimenta periodos de avance e involución. Ahora que el feminismo resulta relevante en tantas esferas de la acción política en el mundo, ya sean locales o internacionales, y que la traducción es, más que nunca, reconocida y valorada como un instrumento en las relaciones políticas, este parece ser un buen momento para reflexionar sobre el estado de la cuestión en torno al feminismo dentro del mundo de la traducción, donde es ya innegable que se entrelazan la política y el lenguaje. Son muchas las preguntas que cabría formularse: ¿sigue siendo la traducción feminista un campo de investigación interesante en España? ¿Han avanzado al mismo ritmo la teoría y la práctica? ¿Han alte…