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Measuring the impact of suspending Umrah, a global mass gathering in Saudi Arabia on the COVID‑19 pandemic (open access)

Measuring the impact of suspending Umrah, a global mass gathering in Saudi Arabia on the COVID‑19 pandemic

This article uses a stratified SEIR epidemic model to evaluate the impact of Umrah, a global Muslim pilgrimage to Mecca, on the spread of the COVID-19 pandemic during the month of Ramadan, the peak of the Umrah season. The analyses provide insights into the effects of global mass gatherings on the progression of the COVID-19 pandemic locally and globally.
Date: September 6, 2021
Creator: Alshammari, Sultanah M.; Almutiry, Waleed K.; Gwalani, Harsha; Algarni, Saeed M. & Saeedi, Kawther
System: The UNT Digital Library
Developmental programming of DNA methylation and gene expression patterns is associated with extreme cardiovascular tolerance to anoxia in the common snapping turtle (open access)

Developmental programming of DNA methylation and gene expression patterns is associated with extreme cardiovascular tolerance to anoxia in the common snapping turtle

This article explores DNA methylation's role in the regulation of gene expression in reptiles. Results show that embryonic hypoxia programs DNA methylation and gene expression patterns and that these changes are associated with enhanced cardiac anoxia tolerance in snapping turtles later in life.
Date: September 6, 2021
Creator: Ruhr, Ilan; Bierstedt, Jacob; Rhen, Turk; Das, Debojyoti; Singh, Sunil Kumar; Miller, Solielle et al.
System: The UNT Digital Library
State of the world's raptors: Distributions, threats, and conservation recommendations (open access)

State of the world's raptors: Distributions, threats, and conservation recommendations

Article exploring the International Union for the Conservation of Nature's Red List to examine the conservation status, distributions, threats, and conservation recommendations for all 557 raptor species.
Date: September 6, 2018
Creator: McClure, Christopher J.W.; Westrip, James R.S.; Johnson, Jeff A.; Schulwitz, Sarah; Virani, Munir Z.; Davies, Robert et al.
System: The UNT Digital Library
A Latent Profile Analysis of Violent Offenders Based on PCL-R Factor Scores: Criminogenic Needs and Recidivism Risk (open access)

A Latent Profile Analysis of Violent Offenders Based on PCL-R Factor Scores: Criminogenic Needs and Recidivism Risk

Article describes study where latent profile analysis was used to investigate if homogeneous latent classes of psychopathy exist within a sample of 215 adult male violent offenders from Berlin, Germany.
Date: September 6, 2019
Creator: Lehmann, Robert Johann Bernhard; Neumann, Craig S.; Hare, Robert Douglas; Biedermann, Jürgen; Dahle, Klaus-Peter & Mokros, Andreas
System: The UNT Digital Library
Inertial Fusion and High-Energy-Density Science in the United States (open access)

Inertial Fusion and High-Energy-Density Science in the United States

Inertial fusion and high-energy density science worldwide is poised to take a great leap forward. In the US, programs at the University of Rochester, Sandia National Laboratories, Los Alamos National Laboratory, Lawrence Livermore National Laboratory (LLNL), the Naval Research Laboratory, and many smaller laboratories have laid the groundwork for building a facility in which fusion ignition can be studied in the laboratory for the first time. The National Ignition Facility (NIF) is being built by the Department of Energy's National Nuclear Security Agency to provide an experimental test bed for the US Stockpile Stewardship Program (SSP) to ensure the dependability of the country's nuclear deterrent without underground nuclear testing. NIF and other large laser systems being planned such as the Laser MegaJoule (LMJ) in France will also make important contributions to basic science, the development of inertial fusion energy, and other scientific and technological endeavors. NIF will be able to produce extreme temperatures and pressures in matter. This will allow simulating astrophysical phenomena (on a tiny scale) and measuring the equation of state of material under conditions that exist in planetary cores.
Date: September 6, 2001
Creator: Tarter, C B
System: The UNT Digital Library
Simultaneous reactions at disk and porous electrodes (open access)

Simultaneous reactions at disk and porous electrodes

Advances in electrochemical engineering are reviewed and the methodology of analysis of electrochemical systems outlined. Examples illustrative of current research concern simultaneous reactions for flow-through porous electrodes and the more fundamental system of a rotating-disk electrode. Here the undesirable side reaction is the formation of dissolved hydrogen, and the main reaction is the deposition of copper from sulfuric acid solutions. Distributions of reaction rate, concentration, and potential describe the detailed system behavior. The side reaction is responsible for the poorly defined limiting-current plateau on the disk electrode and provides a limit for the maximum flow rate at which good recovery can be achieved with the porous electrode. 16 figures.
Date: September 6, 1976
Creator: Newman, J.
System: The UNT Digital Library
Simulation of Edge Plasmas in DIII-D Double-Null Configurations (open access)

Simulation of Edge Plasmas in DIII-D Double-Null Configurations

We present fluid model simulation results for the edge plasma in the DIII-D tokamak with unbalanced double-null magnetic configurations, including cross field drifts. Input parameters are typical of low-power operation in DIII-D. For high-recycling the plasma tends to be detached from all divertor plates. Midplane plasma and electric field profiles are relatively insensitive to the magnetic imbalance. Divertor heat flux profiles exhibit sharp peaks due to cross-field drifts when the ion grad-B drift direction is away from the x-point toward the magnetic axis.
Date: September 6, 2001
Creator: Rensink, M. E.; Lasnier, C. J.; Petrie, T. W.; Porter, G. D. & Rognlien, T D
System: The UNT Digital Library
Design, Implementation and Optimization of a Parallel Monte Carlo Particle Transport Code (open access)

Design, Implementation and Optimization of a Parallel Monte Carlo Particle Transport Code

None
Date: September 6, 2004
Creator: Procassini, R J; Taylor, J M; Greenman, G M; O'Brien, M J & Cullen, D E
System: The UNT Digital Library
Modeling, Fabrication and Testing of a Diamond-Machined Germanium Immersion Grating (open access)

Modeling, Fabrication and Testing of a Diamond-Machined Germanium Immersion Grating

None
Date: September 6, 2002
Creator: Kuzmenko, P J; Little, L M; Davis, P J & Little, S L
System: The UNT Digital Library
Higher-Order Semi-Implicit Projection Methods (open access)

Higher-Order Semi-Implicit Projection Methods

A semi-implicit form of the method of spectral deferred corrections is applied to the solution of the incompressible Navier-Stokes equations. A methodology for constructing semi-implicit projection methods with arbitrarily high order of temporal accuracy in both the velocity and pressure is presented. Three variations of projection methods are discussed which differ in the manner in which the auxiliary velocity and the pressure are calculated. The presentation will make clear that project methods in general need not be viewed as fractional step methods as is often the practice. Two simple numerical examples re used to demonstrate fourth-order accuracy in time for an implementation of each variation of projection method.
Date: September 6, 2001
Creator: Minion, M. L.
System: The UNT Digital Library
Design of Long Induction Linacs (open access)

Design of Long Induction Linacs

A self-consistent design strategy for induction linacs is presented which addresses the issues of brightness preservation against space charge induced emittance growth, minimization of the beam breakup instability and the suppression of beam centroid motion due to chromatic effects (corkscrew) and misaligned focusing elements. A simple steering algorithm is described that widens the effective energy bandwidth of the transport system.
Date: September 6, 1990
Creator: Caporaso, G.J. & Cole, A.G.
System: The UNT Digital Library
A high resolution capacitive imaging sensor for manufacturing applications (open access)

A high resolution capacitive imaging sensor for manufacturing applications

A high resolution capacitive image sensing technique for measuring edge and surface profiles during manufacturing processes has been invented. A prototype device utilizing this technique consists of two 0.020 in. (500 {mu}m) diameter electrodes fabricated on a printed circuit board with a 0.010 in. (250 {mu}m) gap between them. As the device is mechanically scanned over the workpiece, the spatial variations in the edge or surface to be measured interfere with an electric field imposed between the electrodes, altering the mutual capacitance. The sensor functions as a near field proximity sensor producing range images of surface imperfections. This sensor has been used in applications requiring a preview image of burrs on the edge of a machined part and other processes requiring an inspection image after automated deburring operations. 10 refs., 8 figs.
Date: September 6, 1990
Creator: Novak, J. L. & Wiczer, J. J.
System: The UNT Digital Library
Ablation gas dynamics of low-Z materials illuminated by soft x-rays (open access)

Ablation gas dynamics of low-Z materials illuminated by soft x-rays

Though many of our results will have much greater generality, the main purpose of this paper is to provide a simple, accurate, physical theory of what happens when a Planckian spectrum of soft x-rays is incident on one side of the slab of initially cold, dense material, of small nuclear charge Z. Our approach will be to consider in some detail the idealized situation. A semi-infinite (x {le} 0) slab of initially cold (T < 300 K), dense ({rho} {approximately} 1 {minus} 10 g/cc), low-Z (Z < 5) material is suddenly subjected at time t = 0 and thereafter to radiation incoming from x = +{infinity} with a specific intensity in directions toward the slab that is Planckian, characterized by a black-body temperature, T{sub R} in the soft x-ray region.
Date: September 6, 1991
Creator: Hatchett, S.P.
System: The UNT Digital Library
Small power plant reverse trade mission (open access)

Small power plant reverse trade mission

This draft report was prepared as required by Task No. 2 of the US Department of Energy, Grant No. FG07-89ID12850 Reverse Trade Mission to Acquaint International Representatives with US Power Plant and Drilling Technology'' (mission). As described in the grant proposal, this report covers the reactions of attendees toward US technology, its possible use in their countries, and an evaluation of the mission by the staff leaders. Note this is the draft report of one of two missions carried out under the same contract number. Because of the diversity of the mission subjects and the different attendees at each, a separate report for each mission has been prepared. This draft report has been sent to all mission attendees, specific persons in the US Department of Energy and Los Alamos National Lab., the California Energy Commission (CEC), and various other governmental agencies.
Date: September 6, 1989
Creator: unknown
System: The UNT Digital Library
An Update on the Status of the NIF Power Conditioning System (open access)

An Update on the Status of the NIF Power Conditioning System

The National Ignition Facility (NIF) Power Conditioning System provides the pulsed excitation required to drive flashlamps in the laser's optical amplifiers. Modular in design, each of the 192 Main Energy Storage Modules (MESMs) stores up to 2.2 MJ of electrical energy in its capacitor bank before delivering the energy to 20 pairs of flashlamps in a 400 {micro}s pulse (10% power points). The peak current of each MESM discharge is 0.5 MA. Production, installation, commissioning and operation of the NIF Power Conditioning continue to progress rapidly, with the goals of completing accelerated production and commissioning by early 2008, while maintaining an aggressive operation schedule. To date, more than 97% of the required modules have been assembled, shipped and installed in the facility, representing more that 380 MJ of stored energy available for driving NIF flashlamps. The MESMs have displayed outstanding reliability during daily, multiple-shift operations.
Date: September 6, 2007
Creator: Arnold, P. A.; Hulsey, S.; Ullery, G. T.; Petersen, D. E.; Pendleton, D. L.; Ollis, C. W. et al.
System: The UNT Digital Library
More visible effects of the hidden sector (open access)

More visible effects of the hidden sector

There is a growing appreciation that hidden sector dynamics may affect the supersymmetry breaking parameters in the visible sector (supersymmetric standard model), especially when the dynamics is strong and superconformal. We point out that there are effects that have not been previously discussed in the literature. For example, the gaugino masses are suppressed relative to the gravitino mass. We discuss their implications in the context of various mediation mechanisms. The issues discussed include anomaly mediation with singlets, the mu (B mu) problem in gauge and gaugino mediation, and distinct mass spectra for the superparticles that have not been previously considered.
Date: September 6, 2007
Creator: Murayama, Hitoshi; Murayama, Hitoshi; Nomura, Yasunori & Poland, David
System: The UNT Digital Library
Atomistically-informed Dislocation Dynamics in fcc Crystals (open access)

Atomistically-informed Dislocation Dynamics in fcc Crystals

We develop a nodal dislocation dynamics (DD) model to simulate plastic processes in fcc crystals. The model explicitly accounts for all slip systems and Burgers vectors observed in fcc systems, including stacking faults and partial dislocations. We derive simple conservation rules that describe all partial dislocation interactions rigorously and allow us to model and quantify cross-slip processes, the structure and strength of dislocation junctions and the formation of fcc-specific structures such as stacking fault tetrahedra. The DD framework is built upon isotropic non-singular linear elasticity, and supports itself on information transmitted from the atomistic scale. In this fashion, connection between the meso and micro scales is attained self-consistently with core parameters fitted to atomistic data. We perform a series of targeted simulations to demonstrate the capabilities of the model, including dislocation reactions and dissociations and dislocation junction strength. Additionally we map the four-dimensional stress space relevant for cross-slip and relate our findings to the plastic behavior of monocrystalline fcc metals.
Date: September 6, 2006
Creator: Martinez, E.; Marian, J.; Arsenlis, T.; Victoria, M. & Perlado, J. M.
System: The UNT Digital Library
An atomic force microcopy study of the mechanical and electricalproperties of monolayer films of molecules with aromatic end groups (open access)

An atomic force microcopy study of the mechanical and electricalproperties of monolayer films of molecules with aromatic end groups

The effect of intermolecular {pi}-{pi} stacking on the electrical and mechanical properties of monolayer films molecules containing aromatic groups was studied using atomic force microscopy. Two types of aromatic molecules, (4-mercaptophenyl) anthrylacetylene (MPAA) and (4-mercaptophenyl)-phenylacetylene (MPPA) were used as model systems with different {pi}-{pi} stacking strength. Monolayer films of these molecules on Au(111) surfaces exhibited conductivities differing by more than one order of magnitude, MPAA being the most conductive and MPPA the least conductive. The response to compressive loads by the AFM tip was also found to be very different for both molecules. In MPAA films distinct molecular conductivity changes are observed upon mechanical perturbation. This effect however was not observed on the MPPA film, where intermolecular {pi}-{pi} interactions are likely weaker.
Date: September 6, 2007
Creator: Fang, Liang; Park, J.Y.; Ma, H.; Jen, A.K.-Y. & Salmeron, M.
System: The UNT Digital Library
Interaction of Nocturnal Low-Level Jets with Urban Geometries as seen in Joint URBAN 2003 Data (open access)

Interaction of Nocturnal Low-Level Jets with Urban Geometries as seen in Joint URBAN 2003 Data

As accurate modeling of atmospheric flows in urban environments requires sophisticated representation of complex urban geometries, much work has been devoted to treatment of the urban surface. However, the importance of the larger-scale flow impinging upon the urban complex to the flow, transport and dispersion within it and downwind has received less attention. Building-resolving computational fluid dynamics (CFD) models are commonly employed to investigate interactions between the flow and three-dimensional structures comprising the urban environment, however such models are typically forced with simplified boundary conditions that fail to include important regional-scale phenomena that can strongly influence the flow within the urban complex and downwind. This paper investigates the interaction of an important and frequently occurring regional-scale phenomenon, the nocturnal low-level jet (LLJ), with urban-scale turbulence and dispersion in Oklahoma City using data from the Joint URBAN 2003 (JU2003) field experiment. Two simulations of nocturnal tracer release experiments from JU2003 using Lawrence Livermore National laboratory's FEM3MP CFD model yield differing levels of agreement with the observations in wind speed, turbulence kinetic energy (TKE) and concentration profiles in the urban wake, approximately 750m downwind of the central business district. Profiles of several observed turbulence parameters at this location indicate characteristics of both …
Date: September 6, 2006
Creator: Lundquist, J. K. & Mirocha, J. D.
System: The UNT Digital Library
Geometric metastability, quivers and holography (open access)

Geometric metastability, quivers and holography

We use large N duality to study brane/anti-brane configurations on a class of Calabi-Yau manifolds. With only branes present, the Calabi-Yau manifolds in question give rise to N=2 ADE quiver theories deformed by superpotential terms. We show that the large N duality conjecture of hep-th/0610249 reproduces correctly the known qualitative features of the brane/anti-brane physics. In the supersymmetric case, the gauge theories have Seiberg dualities which are represented as flops in the geometry. Moreover, the holographic dual geometry encodes the whole RG flow of the gauge theory. In the non-supersymmetric case, the large N duality predicts that the brane/anti-brane theories also enjoy such dualities, and allows one to pick out the good description at a given energy scale.
Date: September 6, 2007
Creator: Aganagic, Mina; Aganagic, Mina; Beem, Christopher & Freivogel, Ben
System: The UNT Digital Library
Exploring Lifetime Effects in Femtoscopy (open access)

Exploring Lifetime Effects in Femtoscopy

We investigate the role of lifetime effects from resonances and emission duration tails in femtoscopy at RHIC in two Blast-Wave models. We find the non-Gaussian components compare well with published source imaged data, but the value of R{sub out} obtained from Gaussian fits is not insensitive to the non-Gaussian contributions when realistic acceptance cuts are applied to models.
Date: September 6, 2005
Creator: Brown, D.; Soltz, R.; Newby, J. & Kisiel, A.
System: The UNT Digital Library
Alignment validation (open access)

Alignment validation

The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.
Date: September 6, 2008
Creator: ALICE; ATLAS; CMS; LHCb & Golling, Tobias
System: The UNT Digital Library
Material dynamics under extreme conditions of pressure and strain rate (open access)

Material dynamics under extreme conditions of pressure and strain rate

Solid state experiments at extreme pressures (10-100 GPa) and strain rates ({approx}10{sup 6}-10{sup 8}s{sup -1}) are being developed on high-energy laser facilities, and offer the possibility for exploring new regimes of materials science. These extreme solid-state conditions can be accessed with either shock loading or with a quasi-isentropic ramped pressure drive. Velocity interferometer measurements establish the high pressure conditions. Constitutive models for solid-state strength under these conditions are tested by comparing 2D continuum simulations with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples. Lattice compression, phase, and temperature are deduced from extended x-ray absorption fine structure (EXAFS) measurements, from which the shock-induced {alpha}-{omega} phase transition in Ti and the {alpha}-{var_epsilon} phase transition in Fe are inferred to occur on sub-nanosec time scales. Time resolved lattice response and phase can also be measured with dynamic x-ray diffraction measurements, where the elastic-plastic (1D-3D) lattice relaxation in shocked Cu is shown to occur promptly (&lt; 1 ns). Subsequent large-scale molecular dynamics (MD) simulations elucidate the microscopic dynamics that underlie the 3D lattice relaxation. Deformation mechanisms are identified by examining the residual microstructure in recovered samples. The slip-twinning threshold in single-crystal Cu shocked along the [001] direction is shown to …
Date: September 6, 2005
Creator: Remington, Bruce A.; Allen, Patrick; Bringa, Eduaro; Hawreliak, Jim; Ho, Darwin; Lorenz, K. Thomas et al.
System: The UNT Digital Library
Structural Properties of Ge Nanocrystals Embedded inSapphire (open access)

Structural Properties of Ge Nanocrystals Embedded inSapphire

None
Date: September 6, 2006
Creator: Sharp, I. D.; Xu, Q.; Yi, D. O.; Yuan, C. W.; Beeman, J. W.; Yu, K. M. et al.
System: The UNT Digital Library