942 research outputs found
Fast atom diffraction inside a molecular beam epitaxy chamber, a rich combination
Two aspects of the contribution of grazing incidence fast atom diffraction
(GIFAD) to molecular beam epitaxy (MBE) are reviewed here: the ability of GIFAD
to provide \emph{in-situ} a precise description of the atomic-scale surface
topology, and its ability to follow larger-scale changes in surface roughness
during layer-by-layer growth. Recent experimental and theoretical results
obtained for the He atom beam incident along the highly corrugated direction of the (24) reconstructed GaAs(001) surface are
summarized and complemented by the measurements and calculations for the beam
incidence along the weakly corrugated [010] direction where a periodicity twice
smaller as expected is observed. The combination of the experiment, quantum
scattering matrix calculations, and semiclassical analysis allows in this case
to reveal structural characteristics of the surface. For the in situ
measurements of GIFAD during molecular beam epitaxy of GaAs on GaAs surface we
analyse the change in elastic and inelastic contributions in the scattered
beam, and the variation of the diffraction pattern in polar angle scattering.
This analysis outlines the robustness, the simplicity and the richness of the
GIFAD as a technique to monitor the layer-by-layer epitaxial growth
Lesson Learned from Collecting Quantified Self Information via Mobile and Wearable Devices
The ubiquity and affordability of mobile and wearable devices has enabled us to continually and digitally record our daily life activities. Consequently, we are seeing the growth of data collection experiments in several scientific disciplines. Although these have yielded promising results, mobile and wearable data collection experiments are often restricted to a specific configuration that has been designed for a unique study goal. These approaches do not address all the real-world challenges of “continuous data collection” systems. As a result, there have been few discussions or reports about such issues that are faced when “implementing these platforms” in a practical situation. To address this, we have summarized our technical and user-centric findings from three lifelogging and Quantified Self data collection studies, which we have conducted in real-world settings, for both smartphones and smartwatches. In addition to (i) privacy and (ii) battery related issues; based on our findings we recommend further works to consider (iii) implementing multivariate reflection of the data; (iv) resolving the uncertainty and data loss; and (v) consider to minimize the manual intervention required by users. These findings have provided insights that can be used as a guideline for further Quantified Self or lifelogging studies
Entropic corrections to Newton's law
In this short letter we calculate separately the generalized uncertainty
principle (GUP) and self gravitational corrections to the Newton's
gravitational formula. We show that for a complete description of the GUP and
self-gravity effects, both temperature and the entropy must be modified.Comment: 4 pages, Accepted for publication in "Physica Scripta",Title changed,
Major revisio
p-Wave holographic superconductors with Weyl corrections
We study the (3+1) dimensional p-wave holographic superconductors with Weyl
corrections both numerically and analytically. We describe numerically the
behavior of critical temperature with respect to charge density
in a limited range of Weyl coupling parameter and we find in general
the condensation becomes harder with the increase of parameter . In
strong coupling limit of Yang-Mills theory, we show that the minimum value of
obtained from analytical approach is in good agreement with the
numerical results, and finally show how we got remarkably a similar result in
the critical exponent 1/2 of the chemical potential and the order
parameter with the numerical curves of superconductors.Comment: 7 pages, 1 figure, 1 table. One refrence added, presentations
improve
Effect of pioglitazone on decreasing of proteinuria in type 2 diabetic patients with nephropathy
Introduction: Diabetic nephropathy that means albuminuria greater than 30 mg/day, affects about one third of diabetic patients. There are many studies about the effect of different medications for diabetic nephropathy with controversy in their results. So, the aim of the study was to investigate the effect of pioglitazone on decreasing of proteinuria in type II diabetic patients and nephropathy. Methods and materials: It is a double blind clinical trial. At first, 2356 medical carts of the patients were evaluated and 76 patients with type 2 diabetes mellitus with proteinuria greater than 250 mg / day were enrolled in 2 equal groups. In the case group, pioglitazone 15 mg/day was prescribed and patients in the control group received placebo for two months. At the beginning of the study and after 2 months, urinary protein during 24 h was measured in all of the patients and data were entered to SPSS (version23) and evaluated by using Chi- square, Mc Nemar, paired t-test and logistic regression model. Results: At the beginning of the study, urine protein during 24 h in the case and control groups were 957.7 ± 385.1 and 972.1 ± 378.6 respectively (P =.872). So, after 2 months the mean proteinuria in the case and control groups were 647.3 ± 367.2 and 896 ± 372.4 respectively that is valuable (P = 0.005). Pioglitazone had the considerable effect on FBS,HbA1c and blood triglyceride too. Conclusion: The study showed that low dose of pioglitazone is an effective, safe and inexpensive method in reducing of proteinuria in type2 diabetic patients with nephropathy
Stochastic Analysis of Tsunami Hazard of the 1945 Makran Subduction Zone Mw 8.1–8.3 Earthquakes
© 2020 by the authors. Historical records of major earthquakes in the northwestern Indian Ocean along the Makran Subduction Zone (MSZ) indicate high potential tsunami hazards for coastal regions of Pakistan, Iran, Oman, and western India. There are fast-growing and populous cities and ports that are economically important, such as Chabahar (Iran), Gwadar (Pakistan), Muscat (Oman), and Mumbai (India). In this study, we assess the tsunami hazard of the 1945 MSZ event (fatalities ≈300 people) using stochastic earthquake rupture models of Mw 8.1–8.3 by considering uncertainties related to rupture geometry and slip heterogeneity. To quantify the uncertainty of earthquake source characteristics in tsunami hazard analysis, 1000 stochastic tsunami scenarios are generated via a stochastic source modeling approach. There are main objectives of this study: (1) developing stochastic earthquake slip models for the MSZ, (2) comparing results of the simulation with the existing observations of the 1945 event, and (3) evaluating the effect of uncertain fault geometry and earthquake slip based on simulated near-shore wave profiles. The 1945 Makran earthquake is focused upon by comparing model predictions with existing observations, consisting of far-field tsunami waveforms recorded on tide gauges in Karachi and Mumbai and coseismic deformation along the Pakistani coast. The results identify the source model that matches the existing observations of the 1945 Makran event best among the stochastic sources. The length, width, mean slip, and maximum slip of the identified source model are 270 km, 130 km, 2.9 m, and 19.3 m, respectively. Moreover, the sensitivity of the maximum tsunami heights along the coastline to the location of a large-slip area is highlighted. The maximum heights of the tsunami and coseismic deformation results at Ormara are in the range of 0.3–7.0 m and −2.7 to 1.1 m, respectively, for the 1000 stochastic source models.Canada Research Chair program (950-232015) ; the NSERC Discovery Grant; the Royal Society (UK) gran
Gauss-Bonnet holographic superconductors with magnetic field
We study the Gauss-Bonnet (GB) holographic superconductors in the presence of
an external magnetic field. We describe the phenomena away from the probe
limit. We derive the critical magnetic field of the GB holographic
superconductors with backreaction. Our analytical approach matches the
numerical calculations. We calculate the backreaction corrections up to first
order of to the critical temperature and the
critical magnetic field for a GB superconductor. We show that the GB
coupling makes the condensation weaker but the backreaction
corrections make the critical magnetic field stronger.Comment: 9 pages, 4 figures. Accepted for publication by EP
Simulating Supersonic Turbulence in Magnetized Molecular Clouds
We present results of large-scale three-dimensional simulations of weakly
magnetized supersonic turbulence at grid resolutions up to 1024^3 cells. Our
numerical experiments are carried out with the Piecewise Parabolic Method on a
Local Stencil and assume an isothermal equation of state. The turbulence is
driven by a large-scale isotropic solenoidal force in a periodic computational
domain and fully develops in a few flow crossing times. We then evolve the flow
for a number of flow crossing times and analyze various statistical properties
of the saturated turbulent state. We show that the energy transfer rate in the
inertial range of scales is surprisingly close to a constant, indicating that
Kolmogorov's phenomenology for incompressible turbulence can be extended to
magnetized supersonic flows. We also discuss numerical dissipation effects and
convergence of different turbulence diagnostics as grid resolution refines from
256^3 to 1024^3 cells.Comment: 10 pages, 3 figures, to appear in the proceedings of the DOE/SciDAC
2009 conferenc
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