University of Texas at Austin

About: University of Texas at Austin is a education organization based out in Austin, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 94352 authors who have published 206297 publications receiving 9070052 citations. The organization is also known as: UT-Austin & UT Austin.

Systematic AB Initio Gradient Calculation of Molecular Geometries, Force Constants, and Dipole Moment Derivatives

Abstract: Systematic ab initio gradient calculation of molecular geometries, force constants, and dipole moment derivatives is described. A new basis set, denoted 4-21, is presented for first-row atoms. It is nearly equivalent to the 4-31G set but requires less computational effort. Completely optimized Hartree-Fock geometries of 18 molecules are compared using several basis sets, with and without polarization functions. The question of the best representation of molecular force fields is discussed, and a set of standardized internal coordinates is suggested for future work. Quadratic and the most important cubic force constants and dipole moment derivatives of first-row hydrides are calculated using the 4-21 basis set, and the results are compared with those from other basis sets, including near-Hartree-Fock ones. Force-field calculations on larger molecules with the 4-21 basis are summarized. A general formulation of the rotational correction to dipole moment derivatives is given.

Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis

Abstract: The Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the entire sky in five frequency bands between 23 and 94 GHz with polarization-sensitive radiometers. We present 3 year full-sky maps of the polarization and analyze them for foreground emission and cosmological implications. These observations open up a new window for understanding how the universe began and help set a foundation for future observations. WMAP observes significant levels of polarized foreground emission due to both Galactic synchrotron radiation and thermal dust emission. Synchrotron radiation is the dominant signal at l < 50 and ν 40 GHz, while thermal dust emission is evident at 94 GHz. The least contaminated channel is at 61 GHz. We present a model of polarized foreground emission that captures the large angular scale characteristics of the microwave sky. After applying a Galactic mask that cuts 25.7% of the sky, we show that the high Galactic latitude rms polarized foreground emission, averaged over l = 4-6, ranges from ≈5 μK at 22 GHz to 0.6 μK at 61 GHz. By comparison, the levels of intrinsic CMB polarization for a ΛCDM model with an optical depth of τ = 0.09 and assumed tensor-to-scalar ratio r = 0.3 are ≈0.3 μK for E-mode polarization and ≈0.1 μK for B-mode polarization. To analyze the maps for CMB polarization at l < 16, we subtract a model of the foreground emission that is based primarily on a scaling WMAP's 23 GHz map. In the foreground-corrected maps, we detect l(l + 1)C/2π = 0.086 ± 0.029 (μK)2. This is interpreted as the result of rescattering of the CMB by free electrons released during reionization at zr = 10.9 for a model with instantaneous reionization. By computing the likelihood of just the EE data as a function of τ we find τ = 0.10 ± 0.03. When the same EE data are used in the full six-parameter fit to all WMAP data (TT, TE, EE), we find τ = 0.09 ± 0.03. Marginalization over the foreground subtraction affects this value by δτ < 0.01. We see no evidence for B modes, limiting them to l(l + 1)C/2π = -0.04 ± 0.03 (μK)2. We perform a template fit to the E-mode and B-mode data with an approximate model for the tensor scalar ratio. We find that the limit from the polarization signals alone is r < 2.2 (95% CL), where r is evaluated at k = 0.002 Mpc-1. This corresponds to a limit on the cosmic density of gravitational waves of ΩGWh2 < 5 × 10-12. From the full WMAP analysis, we find r < 0.55 (95% CL) corresponding to a limit of ΩGWh2 < 1 × 10-12 (95% CL). The limit on r is approaching the upper bound of predictions for some of the simplest models of inflation, r ~ 0.3.

Generalized second law of thermodynamics in black-hole physics

Abstract: In previous work we introduced the concept of black-hole entropy, which we identified with the surface area of the black hole in question expressed in units of the Planck length squared. We suggested that the appropriate generalization of the second law for a region containing a black hole is that the black-hole entropy plus the common entropy in the black-hole exterior never decreases. Here we establish the validity of this law for the infall of an entropy-bearing system into a much larger and more massive generic stationary black hole. To do this we determine a general lower bound for the increase in black-hole entropy, and an upper bound for the entropy of the system, while allowing for quantum effects at each stage. In passing we show that the generalized second law is a statistical law which becomes over-whelmingly probable in the limit of a macroscopic system. We also consider briefly more general situations. Finally, we give two simple examples of predictions made by the generalized second law for black-hole formation processes.

The Female Sexual Function Index (FSFI): Cross-Validation and Development of Clinical Cutoff Scores

Abstract: The Female Sexual Function Index (FSFI) is a brief, multidimensional scale for assessing sexual function in women. The scale has received initial psychometric evaluation, including studies of reliability, convergent validity, and discriminant validity (Meston, 2003; Rosen et al., 2000). The present study was designed to cross-validate the FSFI in several samples of women with mixed sexual dysfunctions (N = 568) and to develop diagnostic cut-off scores for potential classification of women's sexual dysfunction. Some of these samples were drawn from our previous validation studies (N = 414), and some were added for purposes of the present study (N = 154). The combined data set consisted of multiple samples of women with sexual dysfunction diagnoses (N = 307), including female sexual arousal disorder (FSAD), hypoactive sexual desire disorder (HSDD), female sexual orgasm disorder (FSOD), dyspareunia/vaginismus (pain), and multiple sexual dysfunctions, in addition to a large sample of nondysfunctional controls...