163 research outputs found
Cryogenic Calibration Setup for Broadband Complex Impedance Measurements
Reflection measurements give access to the complex impedance of a material on
a wide frequency range. This is of interest to study the dynamical properties
of various materials, for instance disordered superconductors. However
reflection measurements made at cryogenic temperature suffer from the
difficulty to reliably subtract the circuit contribution. Here we report on the
design and first tests of a setup able to precisely calibrate in situ the
sample reflection, at 4.2 K and up to 2 GHz, by switching and measuring, during
the same cool down, the sample and three calibration standards.Comment: (6 pages, 6 figures
Magnetic field-induced quantum superconductor-insulator transition in
A study of magnetic-field tuned superconductor-insulator transitions in
amorphous thin films shows that quantum
superconductor-insulator transitions are characterized by an unambiguous
signature -- a kink in the temperature profile of the critical magnetic field.
Using this criterion, we show that the nature of the magnetic-field tuned
superconductor-insulator transition depends on the orientation of the field
with respect to the film. For perpendicular magnetic field, the transition is
controlled by quantum fluctuations with indications for the existence of a Bose
insulator; while for parallel magnetic field, the transition is classical,
driven by the breaking of Cooper pairs at the temperature dependent critical
field .Comment: 5 pages, 4 figure
Gender Disparity in Composition and Compensation Among Maryland Hospital Executives
Introduction: Senior executive positions in hospitals have traditionally been held by men, and do not reflect the gender, racial, ethnic, and cultural diversities of the communities they serve. Despite sex parity in medical school graduates, women remain underrepresented in hospital executive leadership positions. In this study, the authors examined differences in gender composition and compensation of Maryland hospital executives.
Methods: The authors examined 47 Maryland hospitals’ publicly available tax forms from 2013-2018. Data collected included hospital revenue and executive positions’ count, salary, and gender. Executive positions included President and/or Chief Executive Officer (P/CEO), Chief Financial Officer (CFO), Chief Medical Officer (CMO), Chief Nursing Officer (CNO), and Chief Operating Officer (COO). All monetary values were inflation-adjusted to the 2017 dollar.
Results: Women executives were underrepresented across most roles: P/CEO (41/272, 15%), CFO (72/260, 28%), CMO (28/182, 15%), and COO (44/147, 30%). CNO showed a higher proportion of women executives (129/140, 92%). There were no significant changes in the proportion of women executives over the study period (p=0.19). Men CNO’s had significantly higher salaries as a percentage of hospital revenue (0.16% vs 0.12%, p=0.04) and men COOs had significantly higher salaries as a percentage of hospital positive profit (3.65% vs 2.24%, p\u3c0.01).
Conclusion: Data from Maryland hospitals suggest that women remain underrepresented in healthcare executive roles. Further, women executives are generally undercompensated compared to men in similar roles. This study further highlights the need for mentorship and dedicated career pathways to improve women representation in leadership roles in healthcare
Axion searches with the EDELWEISS-II experiment
We present new constraints on the couplings of axions and more generic
axion-like particles using data from the EDELWEISS-II experiment. The EDELWEISS
experiment, located at the Underground Laboratory of Modane, primarily aims at
the direct detection of WIMPs using germanium bolometers. It is also sensitive
to the low-energy electron recoils that would be induced by solar or dark
matter axions. Using a total exposure of up to 448 kg.d, we searched for
axion-induced electron recoils down to 2.5 keV within four scenarios involving
different hypotheses on the origin and couplings of axions. We set a 95% CL
limit on the coupling to photons GeV in
a mass range not fully covered by axion helioscopes. We also constrain the
coupling to electrons, , similar to the more
indirect solar neutrino bound. Finally we place a limit on , where is the
effective axion-nucleon coupling for Fe. Combining these results we
fully exclude the mass range keV for DFSZ axions and
keV for KSVZ axions
Proceedings of the third French-Ukrainian workshop on the instrumentation developments for HEP
The reports collected in these proceedings have been presented in the third
French-Ukrainian workshop on the instrumentation developments for high-energy
physics held at LAL, Orsay on October 15-16. The workshop was conducted in the
scope of the IDEATE International Associated Laboratory (LIA). Joint
developments between French and Ukrainian laboratories and universities as well
as new proposals have been discussed. The main topics of the papers presented
in the Proceedings are developments for accelerator and beam monitoring,
detector developments, joint developments for large-scale high-energy and
astroparticle physics projects, medical applications.Comment: 3rd French-Ukrainian workshop on the instrumentation developments for
High Energy Physics, October 15-16, 2015, LAL, Orsay, France, 94 page
Temperature-dependent transport measurements with Arduino
The current performances of single-board microcontrollers render them attractive, not only for basic applications, but also for more elaborate projects, amongst which are physics teaching or research. In this article, we show how temperature-dependent transport measurements can be performed by using an Arduino board, from cryogenic temperatures up to room temperature or above. We focus on two of the main issues for this type of
experiments: the determination of the sample temperature and the measurement of its resistance. We also detail two student-led experiments: evidencing the magnetocaloric effect in Gadolinium and measuring the resistive transition of a high critical temperature superconductor
LiMoO Scintillating Bolometers for Rare-Event Search Experiments
We report on the development of scintillating bolometers based on lithium
molybdate crystals containing molybdenum depleted in the double- active
isotope Mo (LiMoO). We used two
LiMoO cubic samples, 45 mm side and 0.28 kg each,
produced following purification and crystallization protocols developed for
double- search experiments with Mo-enriched LiMoO
crystals. Bolometric Ge detectors were utilized to register scintillation
photons emitted by the LiMoO crystal
scintillators. The measurements were performed in the CROSS cryogenic set-up at
the Canfranc underground laboratory (Spain). We observed that the
LiMoO scintillating bolometers are characterized
by excellent spectrometric performance (3--6 keV FWHM at 0.24--2.6 MeV
's), moderate scintillation signal (0.3--0.6 keV/MeV depending on
light collection conditions) and high radiopurity (Th and Ra
activities are below a few Bq/kg), comparable to the best reported results
of low-temperature detectors based on LiMoO with natural or
Mo-enriched molybdenum content. Prospects of
LiMoO bolometers for use in rare-event search
experiments are briefly discussed.Comment: Prepared for submission to MDPI Sensors; 16 pages, 7 figures, and 3
table
Purification of molybdenum oxide, growth and characterization of medium size zinc molybdate crystals for the LUMINEU program
The LUMINEU program aims at performing a pilot experiment on neutrinoless
double beta decay of 100Mo using radiopure ZnMoO4 crystals operated as
scintillating bolometers. Growth of high quality radiopure crystals is a
complex task, since there are no commercially available molybdenum compounds
with the required levels of purity and radioactive contamination. This paper
discusses approaches to purify molybdenum and synthesize compound for high
quality radiopure ZnMoO4 crystal growth. A combination of a double sublimation
(with addition of zinc molybdate) with subsequent recrystallization in aqueous
solutions (using zinc molybdate as a collector) was used. Zinc molybdate
crystals up to 1.5 kg were grown by the low-thermal-gradient Czochralski
technique, their optical, luminescent, diamagnetic, thermal and bolometric
properties were tested.Comment: Contribution to Proc. of Int. Workshop on Radiopure Scintillators
RPSCINT 2013, 17-20 September 2013, Kyiv, Ukraine; to be published in EPJ Web
of Conferences; expected to be online in January 2014; 6 pages, 6 figures,
and 3 table
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