16,347 research outputs found
Review of: Marsh, C., Unparalleled Reforms: China's Rise, Russia's Fall, and the Interdependence of Transition
No abstract available
Positive Mass Theorem on Manifolds admitting Corners along a Hypersurface
We study a class of non-smooth asymptotically flat manifolds on which metrics
fails to be across a hypersurface . We first give an
approximation scheme to mollify the metric, then we prove that the Positive
Mass Theorem still holds on these manifolds if a geometric boundary condition
is satisfied by metrics separated by .Comment: 17 page
SL(2,C) gravity on noncommutative space with Poisson structure
The Einstein's gravity theory can be formulated as an SL(2,C) gauge theory in
terms of spinor notations. In this paper, we consider a noncommutative space
with the Poisson structure and construct an SL(2,C) formulation of gravity on
such a space. Using the covariant coordinate technique, we build a gauge
invariant action in which, according to the Seiberg-Witten map, the physical
degrees of freedom are expressed in terms of their commutative counterparts up
to the first order in noncommutative parameters.Comment: 12 pages, no figures; v2: 13 pages, clarifications and references
added; v3: clarifications added; v4: more clarifications and references
added, final version to appear in Phys. Rev.
Solubilization of M2 Transmembrane Peptide of Influenza A in Pure Water: Implications for Emergence of Proteins and Protein-embedded Primeval Membranes in Unsalted Oceans
We demonstrated that M2 transmembrane peptide, one of the most hydrophobic sequences in nature, can be solublized to at least ~100 µM in unsalted water without any lipid molecules. Strikingly, the M2 peptide also forms a highly-helical conformation in water which remains almost unchanged even at 95 ºC, as characterized by CD spectroscopy. Our result has critical implications in understanding emergence of proteins and protein-embedded primeval membranes in unsalted oceans
Thermochemistry of yavapaiite KFe(SO4)2: Formation and decomposition
Yavapaiite, KFe(SO4)2, is a rare mineral in nature, but its structure is considered as a reference
for many synthetic compounds in the alum supergroup. Several authors mention the formation of yavapaiite by heating potassium jarosite above ca. 400°C. To understand the thermal decomposition of jarosite, thermodynamic data for phases in the K-Fe-S-O-(H) system, including yavapaiite, are needed. A synthetic sample of yavapaiite was characterized in this work by X-ray
diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal analysis. Based on X-ray diffraction pattern refinement, the unit cell dimensions for this sample were found to be a = 8.152 ± 0.001 Ă
, b = 5.151 ± 0.001 Ă
, c = 7.875
± 0.001 Ă
, and ÎČ = 94.80°. Thermal decomposition indicates that the final breakdown of the yavapaiite structure takes place at 700°C (first major endothermic peak), but the decomposition starts earlier, around 500°C. The enthalpy of formation from the elements of yavapaiite, KFe(SO4)2, ÎH°f = â2042.8 ± 6.2 kJ/mol, was determined by high-temperature oxide melt solution calorimetry. Using literature data for hematite, corundum, and Fe/Al sulfates, the standard entropy and Gibbs free energy of formation of yavapaiite at 25°C (298 K) were calculated as S°(yavapaiite) = 224.7 ± 2.0 J.molâ1.Kâ1 and ÎG°f = â1818.8 ± 6.4 kJ/mol. The
equilibrium decomposition curve for the reaction jarosite = yavapaiite + Fe2O3 + H2O has been calculated, at pH2O = 1 atm, the phase boundary lies at 219 ± 2°C
Recipient of the 2012 Alumni Distinguished Leadership Award
Before turning 30, Winjie Tang Miao was named a hospital president and in 2011, she was tapped to lead the development of the newest hospital in the Texas Health Resources system. Miaoâs rise to the top follows her success in previous health care administration leadership roles. Miao oversaw the development of more than $500 million in construction projects and the growth and development of a nationally-recognized breast health program. She is recognized as a âtrue visionaryâ with âa strong ability to grow inpatient and outpatient volumes, expand services in the community and advance quality in many areas of the hospital.â Miao is also active in her community and has won several awards, including recognition by Beckerâs Hospital Review as one of â25 Healthcare Leaders Under Age 40â in 2011 and one of Modern Healthcareâs âUp and Comersâ in 2008. She says some of her most fulfilling work was when she served as a clinic director opening a new medical clinic in an underserved village in Africa. Miao received her B.S. in Biomedical Engineering from Johns Hopkins University and her Master of Healthcare Administration degree from the University of North Carolina at Chapel Hill
- âŠ