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Are we centering the adult in youth media education? Decolonizing the reception of youth-produced media texts (open access)

Are we centering the adult in youth media education? Decolonizing the reception of youth-produced media texts

This article explores how the assumptions and values we hold are reflected in our reception and circulation of youth-produced texts in ways that colonize youth interests, sensibilities, and aesthetics. This is the accepted manuscript version of the article.
Date: May 19, 2022
Creator: Vickery, Jacqueline Ryan
System: The UNT Digital Library
Thermal Stress Has Minimal Effects on Bacterial Communities of Thermotolerant Symbiodinium Cultures (open access)

Thermal Stress Has Minimal Effects on Bacterial Communities of Thermotolerant Symbiodinium Cultures

Article comparing the microbial communities of three isolates from different species of the genus Symbiodinium (formerly known as Symbiodinium clade A) with different ecophysiology, levels of interaction with the animal host, and thermal adaptations. Results suggest that bacteria associated or co-cultured with thermotolerant Symbiodinium might play an important role in thermotolerance.
Date: May 19, 2022
Creator: Díaz-Almeyda, Erika M.; Ryba, Tyrone; Ohdera, Aki H.; Shafer, Natali; Link, Caroline; Prado-Zapata, Marcela et al.
System: The UNT Digital Library
People of Color, People of Faith: The Effect of Social Capital and Religion on the Political Participation of Marginalized Communities (open access)

People of Color, People of Faith: The Effect of Social Capital and Religion on the Political Participation of Marginalized Communities

Article exploring how religion, social capital, and nativity intersect in the political mobilization of racial minorities. Collaborative Multiracial Post-Election Survey (CMPS) 2016 data is used to examine the connection between social capital, religion, and political behavior in a novel attempt to systematically identify the unique role of churches in the mobilization of racial minority communities.
Date: May 19, 2020
Creator: Huckle, Kiku & Silva, Andrea
System: The UNT Digital Library

Commentary on "Correlation of solubility of hexamethylene-1,6-bisthiosulphate disodium salt dihydrate versus dielectric constants of water + ethanol mixtures"

This article discusses the finding that Apelblat model equation coefficients are found to give calculated mole fractions that exceed unity for the solubility of hexamethylene-1,6-bisthiosulphate disodium salt dihydrate dissolved in binary aqueous-ethanol solvent mixtures.
Date: May 19, 2017
Creator: Acree, William E. (William Eugene) & Yang, Chunhui
System: The UNT Digital Library
Automated Creation of Analytic Catalog Records for Born-Digital Journal Articles (open access)

Automated Creation of Analytic Catalog Records for Born-Digital Journal Articles

Article summarizing the approach to bibliographic metadata development at the University of Michigan Library for journal articles published and archived in HathiTrust.
Date: May 19, 2015
Creator: Hawkins, Kevin S.
System: The UNT Digital Library
The Grammaticalization of the Spanish Complement-taking Verb without a Complementizer (open access)

The Grammaticalization of the Spanish Complement-taking Verb without a Complementizer

This article examines authentic data samples taken from the Corpus de Referencia del Español Actual (CREA) to uncover any semantic trends commonly observed in verbs taking a sentential complement without the complementizer que in Spanish.
Date: May 19, 2015
Creator: Yoon, Jiyoung
System: The UNT Digital Library
Density Functional Theory in Surface Chemistry and Catalysis (open access)

Density Functional Theory in Surface Chemistry and Catalysis

Recent advances in the understanding of reactivity trends for chemistry at transition metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. Current status of the field is discussed with an emphasis on the role of coupling between theory and experiment and future challenges.
Date: May 19, 2011
Creator: Norskov, Jens
System: The UNT Digital Library
Echo-Enabled Harmonic Generation for Seeded FELs (open access)

Echo-Enabled Harmonic Generation for Seeded FELs

In the x-ray wavelengths, the two leading FEL concepts are the self-amplified spontaneous emission (SASE) configuration and the high-gain harmonic generation (HGHG) scheme. While the radiation from a SASE FEL is coherent transversely, it typically has rather limited temporal coherence. Alternatively, the HGHG scheme allows generation of fully coherent radiation by up-converting the frequency of a high-power seed laser. However, due to the relatively low up-frequency conversion efficiency, multiple stages of HGHG FEL are needed in order to generate x-rays from a UV laser. The up-frequency conversion efficiency can be greatly improved with the recently proposed echo-enabled harmonic generation (EEHG) technique. In this work we will present the concept of EEHG, and address some practically important issues that affect the performance of the seeding. We show how the EEHG can be incorporated in the FEL scheme and what is the expected performance of the EEHG seeded FEL. We will then briefly describe the first proof-of-principle EEHG experiment carried out at the Next Linear Collider Test Accelerator (NLCTA) at SLAC. We will also discuss latest advances in the echo-scheme approach, and refer to subsequent modifications of the original concept.
Date: May 19, 2011
Creator: Stupakov, G.
System: The UNT Digital Library
Exascale Algorithms for Generalized MPI_Comm_split (open access)

Exascale Algorithms for Generalized MPI_Comm_split

None
Date: May 19, 2011
Creator: Moody, A T; Ahn, D H & de Supinski, B R
System: The UNT Digital Library
The National Ignition Facility: Status and Progress Towards Fusion Ignition (open access)

The National Ignition Facility: Status and Progress Towards Fusion Ignition

None
Date: May 19, 2011
Creator: Moses, Edward
System: The UNT Digital Library
The Nature of Accelerating Modes in PBG Fibers (open access)

The Nature of Accelerating Modes in PBG Fibers

Transverse magnetic (TM) modes with phase velocities at or just below the speed of light, c, are intended to accelerate relativistic particles in hollow-core, photonic band gap (PBG) fibers. These are so-called 'surface defect modes', being lattice modes perturbed by the defect to have their frequencies shifted into the band gap, and they can have any phase velocity. PBG fibers also support so-called 'core defect modes' which are characterized as having phase velocities always greater than c and never cross the light line. In this paper we explore the nature of these two classes of accelerating modes and compare their properties.
Date: May 19, 2011
Creator: Noble, TRobert J.
System: The UNT Digital Library
The Space-Based Telescopes for Actionable Refinement of Ephemeris Pathfinder Mission (open access)

The Space-Based Telescopes for Actionable Refinement of Ephemeris Pathfinder Mission

None
Date: May 19, 2011
Creator: Simms, L.; De Vries, W.; RIot, V.; Olivier, S.; Pertica, A.; Bauman, B. et al.
System: The UNT Digital Library
Steady-State Microbunching in a Storage Ring for Generating Coherent Radiation (open access)

Steady-State Microbunching in a Storage Ring for Generating Coherent Radiation

Synchrotrons and storage rings deliver radiation across the electromagnetic spectrum at high repetition rates, and free electron lasers (FELs) produce radiation pulses with high peak brightness. However, at present few light sources can generate both high repetition rate and high brightness outside the optical range. We propose to create steady-state microbunching (SSMB) in a storage ring to produce coherent radiation at a high repetition rate or in continuous wave (CW) mode. In this paper we describe a general mechanism for producing SSMB and give sample parameters for EUV lithography and sub-millimeter sources. We also describe a similar arrangement to produce two pulses with variable spacing for pump-probe experiments. With technological advances, SSMB could reach the soft X-ray range (< 10 nm).
Date: May 19, 2011
Creator: Ratner, Daniel F.; /Stanford U., Appl. Phys. Dept. & Chao, Alexander W.
System: The UNT Digital Library
The degree of 5f electron localization in URu2Si2: electron energy-loss spectroscopy and spin-orbit sum rule analysis (open access)

The degree of 5f electron localization in URu2Si2: electron energy-loss spectroscopy and spin-orbit sum rule analysis

We examine the degree of 5f electron localization in URu{sub 2}Si{sub 2} using spin-orbit sum rule analysis of the U N{sub 4,5} (4d {yields} 5f) edge. When compared to {alpha}-U metal, US, USe, and UTe, which have increasing localization of the 5f states, we find that the 5f states of URu{sub 2}Si{sub 2} are more localized, although not entirely. Spin-orbit analysis shows that intermediate coupling is the correct angular momentum coupling mechanism for URu{sub 2}Si{sub 2} when the 5f electron count is between 2.6 and 2.8. These results have direct ramifications for theoretical assessment of the hidden order state of URu{sub 2}Si{sub 2}, where the degree of localization of the 5f electrons and their contribution to the Fermi surface are critical.
Date: May 19, 2010
Creator: Jeffries, J R; Moore, K T; Butch, N P & Maple, M B
System: The UNT Digital Library
Design Methodology and Consideratios for NOVA 53 MHZ RF Cavities (open access)

Design Methodology and Consideratios for NOVA 53 MHZ RF Cavities

The NO?A Experiment will construct a detector optimized for electron neutrino detection in the existing Neutrino at Main Injector (NuMI) beamline. This beamline is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. The cavities will operate at 53 MHz and three of them will be installed in the Recycler beamline. Thermal stability of the cavities is crucial since this affects the tuning. Results of finite element thermal and structural analysis involving the copper RF cavity will be presented.
Date: May 19, 2010
Creator: Ader, C. & Wildman, D.W.
System: The UNT Digital Library
Electrodeposition of U and Pu on Thin C and Ti Substrates (open access)

Electrodeposition of U and Pu on Thin C and Ti Substrates

Physics experiments aimed at deducing key parameters for use in a variety of programs critical to the mission of the National Laboratories require actinide targets placed onto various substrates. The target material quantity and the substrate desired depend upon the type of experiment being designed. The physicist(s) responsible for the experimental campaign will consult with the radiochemistry staff as to the feasibility of producing a desired target/substrate combination. In this report they discuss the production of U and Pu targets on very thin C and Ti substrates. The techniques used, plating cells designed for, tips, and limits is discussed.
Date: May 19, 2010
Creator: Henderson, R. A. & Gostic, J. M.
System: The UNT Digital Library
The influence of displacement damage on deuterium retentionin tungsten exposed to divertor plasma in DIII-D (open access)

The influence of displacement damage on deuterium retentionin tungsten exposed to divertor plasma in DIII-D

None
Date: May 19, 2010
Creator: Wampler, W R; Rudakov, D L & Lasnier, C J
System: The UNT Digital Library
Progress with Tevatron Electron Lens Head-On Beam-Beam Compensation (open access)

Progress with Tevatron Electron Lens Head-On Beam-Beam Compensation

Tevatron electron lenses have been successfully used to mitigate bunch-to-bunch differences caused by longrange beam-beam interactions. For this purpose, the electron beam with uniform transverse density distribution was used. Another planned application of the electron lens is the suppression of tune spread due to head-on beam-beam collisions. For this purpose, the transverse distribution of the E{sup -} beam must be matched to that of the antiproton beam. In 2009, the Gaussian profile electron gun was installed in one of the Tevatron electron lenses. We report on the first experiments with non-linear beam-beam compensation. Discussed topics include measurement and control of the betatron tune spread, importance of the beam alignment and stability, and effect of electron lens on the antiproton beam lifetime.
Date: May 19, 2010
Creator: Valishev, A.; Kuznetsov, G.; Shiltsev, V.; Stancari, G. & Zhang, X.
System: The UNT Digital Library
A Review of X-ray Diagnostic Calibrations in the 2 to 100 keV Region Using the High Energy X-ray Calibration Facility (HEX) (open access)

A Review of X-ray Diagnostic Calibrations in the 2 to 100 keV Region Using the High Energy X-ray Calibration Facility (HEX)

The precise and accurate measurement of X-rays in the 2 keV to 100 keV region is crucial to the understanding of HED plasmas and warm dense matter in general. With the emergence of inertially confined plasma facilities as the premier platforms for ICF, laboratory astrophysics, and national security related plasma experiments, the need to calibrate diagnostics in the high energy X-ray regime has grown. At National Security Technologies High Energy X-ray Calibration Facility (HEX) in Livermore, California, X-ray imagers, filter-fluorescer spectrometers, crystal spectrometers, image plates, and nuclear diagnostics are calibrated. The HEX can provide measurements of atomic line radiation, X-ray flux (accuracy within 10%), and X-ray energy (accuracy within 1%). The HEX source is comprised of a commercial 160 kV X-ray tube, a fluorescer wheel, a filter wheel, and a lead encasement. The X-ray tube produces a Tungsten bremsstrahlung spectrum which causes a foil to fluoresce line radiation. To minimize bremsstrahlung in the radiation for calibration we also provide various foils as filters. For experimental purposes, a vacuum box capable of 10{sup -7} Torr, as well as HPGe and CdTe radiation detectors, are provided on an optical table. Most geometries and arrangements can be changed to meet experimental needs.
Date: May 19, 2010
Creator: Ali, Zaheer; Pond, T.; Buckles, R. A.; Maddox, B. R.; Chen, C. D.; DeWald, E. L. et al.
System: The UNT Digital Library
Scaling of divertor heat flux profile widths in DIII-D (open access)

Scaling of divertor heat flux profile widths in DIII-D

None
Date: May 19, 2010
Creator: Lasnier, C. J.; Makowski, M. A.; Boedo, J. A.; Allen, S. L.; Brooks, N. H.; Hill, D. N. et al.
System: The UNT Digital Library
Simplified Approach to Evaluation of Beam-Beam Tune Spread Compression by Electron Lens (open access)

Simplified Approach to Evaluation of Beam-Beam Tune Spread Compression by Electron Lens

One of the possible ways to increase luminosity of hadron colliders is the compensation of beam-beam tunespread with an electron lens (EL). At the same time, EL as an additional nonlinear element in the lattice can increase strength of nonlinear resonances so that its overall effect on the beam lifetime will be negative. Time-consuming numerical simulations are often used to study the effects of the EL. In this report we present a simplified model, which uses analytical formulae derived for certain electron beam profiles. Based on these equations the idealized shapes of the compressed tune spread can be rapidly calculated. Obtained footprints were benchmarked against several reference numerical simulations for the Tevatron in order to evaluate the selected configurations. One of the tested criteria was the so-called 'folding' of the compensated footprint, which occurs when particles with different betatron amplitudes have the same tune shift. Also studied were the effects of imperfections, including misalignment of the electron and proton beams, and mismatch of their shapes.
Date: May 19, 2010
Creator: Romanov, A. L.; Valishev, A. A. & Shiltsev, V.
System: The UNT Digital Library
Simulations of Head-On Beam-Beam Compensation at RHIC and LHC (open access)

Simulations of Head-On Beam-Beam Compensation at RHIC and LHC

Electron lenses are proposed as a way to mitigate head-on beam-beam effects for RHIC and LHC upgrades. An extensive effort was put together within the US LARP in order to develop numerical simulations of beam-beam effects in the presence of electron lenses. In this report the results of numerical beam-beam simulations for RHIC and LHC are presented. The effect of electron lenses is demonstrated and sensitivity of beam-beam compensation to machine parameters is discussed.
Date: May 19, 2010
Creator: Valishev, A.
System: The UNT Digital Library
Toroidally resolved structure of heat flux in RMP H-mode discharges on DIII-D (open access)

Toroidally resolved structure of heat flux in RMP H-mode discharges on DIII-D

None
Date: May 19, 2010
Creator: Jakubowski, M. W.; Evans, T. E.; Fenstermacher, M. E.; Lasnier, C. J.; Schmitz, O.; Wolf, R. C. et al.
System: The UNT Digital Library
Broad, intense, quiescent beam of singly charged metal ions obtained by extraction from self-sputtering plasma far above the runaway threshold (open access)

Broad, intense, quiescent beam of singly charged metal ions obtained by extraction from self-sputtering plasma far above the runaway threshold

Dense metal plasmas obtained by self-sputtering far above the runway threshold are well suited to generate intense quiescent ion beams. The dilemma of high current density and charge state purity can be solved when using target materials of low surface binding energy by utilizing non-resonant exchange reactions before ion extraction. Space-charge-limited quiescent beams of Cu+, Zn+, and Bi+ with ~;;10 mA/cm2 have been obtained through multi-aperture gridded ion extraction up to 45 kV from self-sputtering plasmas.
Date: May 19, 2009
Creator: Anders, Andre & Oks, Efim
System: The UNT Digital Library