Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 11 of 11

Full-Text Articles in Physics

Early Rayleigh-Scatter Lidar Temperature Measurements From The Lower Thermosphere, Leda Sox, Vincent B. Wickwar May 2015

Early Rayleigh-Scatter Lidar Temperature Measurements From The Lower Thermosphere, Leda Sox, Vincent B. Wickwar

Leda Sox

Rayleigh-scatter lidar observations were made on many clear nights at the Atmospheric Lidar Observatory (ALO) at Utah State University (USU) from 1993 to 2004 in the altitude range 45–90 km. An upgraded facility, 66 times more sensitive, has been brought on line. It has resulted in temperature measurements with maximum altitudes that extend into new territory—the lower thermosphere. All-night temperature averages have been recorded up to an altitude of 114 km. Temperatures from each month, starting in June 2014, are presented and discussed. They are compared to each other, to the ALO-USU climatology from the original lidar, and to temperatures …


Unmasking The Mysteries Of High-Mass X-Ray Binaries (Hmxbs): The Role Of The Electron Beam Ion Trap (Ebit), Carey L. Baxter, Greg Brown, Natalie Hell Aug 2012

Unmasking The Mysteries Of High-Mass X-Ray Binaries (Hmxbs): The Role Of The Electron Beam Ion Trap (Ebit), Carey L. Baxter, Greg Brown, Natalie Hell

Carey L Baxter

The Electron Beam Ion Trap (EBIT) uses a very narrow electron beam (~60μm) to excite and trap ions. X-ray emissions of the excited ions are then diffracted and analyzed. I studied specific spectral emission lines of ionized silicon. This data can be used as a point of reference for similar spectra measured by the satellite Chandra so that the Doppler shift due to wind around the accretion disks of High Mass X-ray Binaries (HMXBs) can be calculated. HMXBs are pairs of stars that are luminous in X-rays. They are composed of a donor star that gives up mass to an …


Essentials Of The Theory Of Abstraction - Lecture, Subhajit Kumar Ganguly Jan 2012

Essentials Of The Theory Of Abstraction - Lecture, Subhajit Kumar Ganguly

Subhajit Kumar Ganguly

In not favouring solutions or sets of solutions, the principle of zero-postulation drives away any unwanted incompleteness from the description of the world. It is the interactions between the possible exhaustive set of solutions that creates the impression pointedness or directiveness in the universe, leading to the formation of clusters, as discussed earlier. These interactions may be chaotic in nature, giving rise to attractor points where the directiveness inside any given system asymptotically seem to approach. It is this directiveness, in turn, inside a given system or in the universe as a whole, that is the cause of all known …


Analysis Of The Theory Of Abstraction, Subhajit Kumar Ganguly Jan 2011

Analysis Of The Theory Of Abstraction, Subhajit Kumar Ganguly

Subhajit Kumar Ganguly

In this paper,a few more implications of the laws of physical transactions as per the Theory of Abstraction are dealt with.Analysis of these implications suggests the existence of `hidden` mass and `hidden` energy in a given physical transaction.Trajectory - examination of such possible transport is carried out. Relativistic cyclist phenomena are also dealt with in this paper.


Dielectric Relaxation Behaviour Of Glycine In Acqueous Solution Medium In The Microwave Frequency Region, Ajaya Kumar Kavala Apr 2008

Dielectric Relaxation Behaviour Of Glycine In Acqueous Solution Medium In The Microwave Frequency Region, Ajaya Kumar Kavala

Mr Ajaya Kumar Kavala

No abstract provided.


Direct Observation Of H2 Binding To A Metal Oxide Surface, J. Z. Larese, T. Arnold, L. Frazier, R. J. Hinde, A. J. Ramirez-Cuesta Jan 2008

Direct Observation Of H2 Binding To A Metal Oxide Surface, J. Z. Larese, T. Arnold, L. Frazier, R. J. Hinde, A. J. Ramirez-Cuesta

Robert Hinde

Inelastic neutron scattering is used to probe the dynamical response of H2 films adsorbed on MgO(100) as a function of film thickness. Concomitant diffraction measurements and a reduced-dimensionality quantum dynamical model provide insight into the molecule-surface interaction potential. At monolayer thickness, the rotational motion is strongly influenced by the surface, so that the molecules behave like quasiplanar rotors. These findings have a direct impact on understanding how molecular hydrogen binds to the surface of materials used in catalytic and storage applications.


Interaction-Induced Dipole Moment Of The Ar–H2 Dimer: Dependence On The H2 Bond Length, Robert J. Hinde Jan 2006

Interaction-Induced Dipole Moment Of The Ar–H2 Dimer: Dependence On The H2 Bond Length, Robert J. Hinde

Robert Hinde

We present ab initio calculations of the interaction-induced dipole moment of the Ar–H2 van der Waals dimer. The primary focus of our calculations is on the H2 bond length dependence of the dipole moment, which determines the intensities of both the collision-induced H2 = 1 ← 0 fundamental band in gaseous Ar–H2 mixtures and the dopant-induced H2 = 1 ← 0 absorption feature in Ar-doped solid H2 matrices. Our calculations employ large atom-centered basis sets, diffuse bond functions positioned between the two monomers, and a coupled cluster treatment of valence electron correlation; core-valence correlation …


Population Size Bias In Descendant-Weighted Diffusion Quantum Monte Carlo Simulations, G. Lee Warren, Robert Hinde Jan 2006

Population Size Bias In Descendant-Weighted Diffusion Quantum Monte Carlo Simulations, G. Lee Warren, Robert Hinde

Robert Hinde

We consider the influence of population size on the accuracy of diffusion quantum Monte Carlo simulations that employ descendant weighting or forward walking techniques to compute expectation values of observables that do not commute with the Hamiltonian. We show that for a simple model system, the d-dimensional isotropic harmonic oscillator, the population size must increase rapidly with d in order to ensure that the simulations produce accurate results. When the population size is too small, expectation values computed using descendant-weighted diffusion quantum Monte Carlo simulations exhibit significant systematic biases.


Vibrational Dependence Of The H2–H2 C6 Coefficients, Robert Hinde Jan 2005

Vibrational Dependence Of The H2–H2 C6 Coefficients, Robert Hinde

Robert Hinde

We use the sum-over-states formalism to compute the imaginary-frequency dipole polarizabilities for H2, as a function of the H–H bond length, at the full configuration interaction level of theory using atom-centered d-aug-cc-pVQZ basis sets. From these polarizabilities, we obtain isotropic and anisotropic C6 dispersion coefficients for a pair of H2 molecules as functions of the two molecules’ bond lengths.


Infrared-Active Vibron Bands Associated With Substitutional Impurities In Solid Parahydrogen, Robert Hinde Jan 2003

Infrared-Active Vibron Bands Associated With Substitutional Impurities In Solid Parahydrogen, Robert Hinde

Robert Hinde

We present a model for the line shapes of infrared-active Q1(0) vibron bands observed in solid parahydrogen doped with low concentrations of spherical substitutional impurities. The line shapes are highly sensitive to the H2 vibrational dependence of the dopant–H2 interaction. When this vibrational dependence is strong, the dopant can trap the infrared-active vibron in its first solvation shell; in this case, the trapped vibron manifests itself in the absorption spectrum as a narrow feature to the red of the pure solid’s vibron band.


The He-Lih Potential Energy Surface Revisited. I. An Interpolated Rigid Rotor Surface, Robert Hinde Jan 1999

The He-Lih Potential Energy Surface Revisited. I. An Interpolated Rigid Rotor Surface, Robert Hinde

Robert Hinde

We reconsider the potential energy surface of the He–LiH system recently examined by Gianturco and co-workers [F. A. Gianturco et al., Chem. Phys. 215, 227 (1997)]. We compute the He–LiH interaction energy at the CCSD(T) level using large correlation consistent atomic basis sets supplemented with bond functions. To capture the severe anisotropy of the He–LiH potential, we interpolate our ab initio points in the angular direction with cubic splines, then expand the splines in terms of Legendre polynomials. The resulting smooth potential surface differs substantially from that of Gianturco et al.; in particular, our attractive He–LiH well is more …