659 research outputs found
Thermal induced flow oscillations in heat exchangers for supercritical fluids
Analytical model has been developed to predict possible unstable behavior in supercritical heat exchangers. From complete model, greatly simplified stability criterion is derived. As result of this criterion, stability of heat exchanger system can be predicted in advance
Stability investigation of thermally induced flow oscillations in cryogenic heat exchangers Final report
Analytic model of thermal flow oscillations in heat exchangers for supercritical fluid
Monitoring of the radio galaxy M 87 at Very High Energy with MAGIC during a low emission state between 2012 and 2015
AbstractWe present the preliminary results from observing the nearby radio galaxy M 87 for 156 hours (between the years 2012 and 2015) with the MAGIC telescopes, which lead to a significant very high energy (VHE, E > 100 GeV) detection of the source in quiescent states each year. Our VHE analysis combined with quasi-simultaneous data at other energies (from gamma-rays, X-rays, optical and radio) provides a unique opportunity to study the source variability and its broadband spectral energy distribution, which is found to disfavour a one-zone synchrotron/synchrotron self-Compton model. Therefore, other alternative scenarios for the photon emission are explored. We also find that the VHE emission is compatible with being produced close to the source radio core as previous data already indicated. A detailed paper presenting full results of the observing campaign is in preparation
The role of ultrafast sequences MRI in the diagnostic evaluation and in the therapeutic option in female stress urinary incontinence.
Abstract 58
InAlAs solar cell on a GaAs substrate employing a graded InxGa1-xAs-InP metamorphic buffer layer
Single junction In0.52Al0.48As solar cells have been grown on a (100) GaAs substrate by employing a 1 mu m thick compositionally graded InxGa1-xAs/InP metamorphic buffer layer to accommodate the 3.9% mismatch. Cells processed from the 0.8 mu m thick InAlAs layers had photovoltaic conversion efficiency of 5% with an open circuit voltage of 0.72 V, short-circuit current density of 9.3 mA/cm(2), and a fill factor of 74.5% under standard air mass 1.5 illumination. The threading dislocation density was estimated to be 3 x 10(8) cm(-2). (C) 2013 American Institute of Physics. (http://dx.doi.org/10.1063/1.4789521
Nonisospectral integrable nonlinear equations with external potentials and their GBDT solutions
Auxiliary systems for matrix nonisospectral equations, including coupled NLS
with external potential and KdV with variable coefficients, were introduced.
Explicit solutions of nonisospectral equations were constructed using the GBDT
version of the B\"acklund-Darboux transformation
Endometriosis and pregnancy. a single institution experience
Endometriosis may compromise the physiological course of pregnancy. The aim of this prospective observational study was to evaluate whether endometriosis causes a higher prevalence of obstetric and neonatal complications as well as a higher risk of caesarean section and to detect a possible correlation between the presence, type, and location of endometriosis and obstetric complications, previous surgery, and pregnancy outcome, as well as the influence of pregnancy on the course of the disease. We compared two cohorts of women with spontaneous pregnancy, with and without endometriosis. Obstetric and neonatal outcomes, mode of delivery, presence, type, and location of endometriotic lesions and the effect of pregnancy on the disease were analyzed. A total of 425 pregnancies were evaluated: 145 cases and 280 controls. Patients with endometriosis showed a higher incidence of miscarriage, threatened miscarriage, threatened preterm labor, preterm delivery, placental abruption, and a higher incidence of caesarean section. A significant correlation with pregnancy-induced hypertension and preeclampsia was found in the presence of adenomyosis. No difference in fetal outcome was found. One case of hemoperitoneum during pregnancy was observed. Pregnancy in women with endometriosis carries a higher risk of obstetric complications, such as miscarriage, threatened miscarriage, preterm labor, preterm birth, and a higher caesarean section rate. Endometriosis does not seem to influence fetal well-being
A new limit on the light speed isotropy from the GRAAL experiment at the ESRF
When the electrons stored in the ring of the European Synchrotron Radiation
Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in
flight) the lower energy of the scattered electron spectra, the Compton Edge
(CE), is given by the two body photon-electron relativistic kinematics and
depends on the velocity of light. A precision measurement of the position of
this CE as a function of the daily variations of the direction of the electron
beam in an absolute reference frame provides a one-way test of Relativistic
Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF
measurements improve the previously existing one-way limits, thus showing the
efficiency of this method and the interest of further studies in this
direction.Comment: Proceed. MG12 meeting, Paris, July, 200
Limits on light-speed anisotropies from Compton scattering of high-energy electrons
The possibility of anisotropies in the speed of light relative to the
limiting speed of electrons is considered. The absence of sidereal variations
in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains
such anisotropies representing the first non-threshold collision-kinematics
study of Lorentz violation. When interpreted within the minimal Standard-Model
Extension, this result yields the two-sided limit of 1.6 x 10^{-14} at 95%
confidence level on a combination of the parity-violating photon and electron
coefficients kappa_{o+} and c. This new constraint provides an improvement over
previous bounds by one order of magnitude.Comment: 4 pages, 4 figure
Designing magnetic properties in CrSBr through hydrostatic pressure and ligand substitution
The ability to control magnetic properties of materials is crucial for
fundamental research and underpins many information technologies. In this
context, two-dimensional materials are a particularly exciting platform due to
their high degree of tunability and ease of implementation into nanoscale
devices. Here we report two approaches for manipulating the A-type
antiferromagnetic properties of the layered semiconductor CrSBr through
hydrostatic pressure and ligand substitution. Hydrostatic pressure compresses
the unit cell, increasing the interlayer exchange energy while lowering the
N\'eel temperature. Ligand substitution, realized synthetically through Cl
alloying, anisotropically compresses the unit cell and suppresses the
Cr-halogen covalency, reducing the magnetocrystalline anisotropy energy and
decreasing the N\'eel temperature. A detailed structural analysis combined with
first-principles calculations reveal that alterations in the magnetic
properties are intricately related to changes in direct Cr-Cr exchange
interactions and the Cr-anion superexchange pathways. Further, we demonstrate
that Cl alloying enables chemical tuning of the interlayer coupling from
antiferromagnetic to ferromagnetic, which is unique amongst known
two-dimensional magnets. The magnetic tunability, combined with a high ordering
temperature, chemical stability, and functional semiconducting properties, make
CrSBr an ideal candidate for pre- and post-synthetic design of magnetism in
two-dimensional materials.Comment: Main text: 17 pages, 4 figures. Supporting Information: 34 pages, 32
figures, 4 table
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