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A Highly Contiguous and Annotated Genome Assembly of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) (open access)

A Highly Contiguous and Annotated Genome Assembly of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus)

Article asserts that the Lesser Prairie-Chicken (Tympanuchus pallidicinctus; LEPC) is an iconic North American prairie grouse, renowned for ornate and spectacular breeding season displays, a species that has been declining in population across much of its historical range, with corresponding precipitous declines in contemporary population abundance, largely due to climatic and anthropogenic factors. The authors describe an annotated reference genome that was generated from a LEPC sample collected from the southern DPS.
Date: March 17, 2023
Creator: Black, Andrew N.; Bondo, Kristin J.; Mularo, Andrew; Hernandez, Alvaro; Yu, Yachi; Stein, Carleigh M. et al.
System: The UNT Digital Library
Polymorphic nature of {332} 〈 113 〉 twinning mode in BCC alloys (open access)

Polymorphic nature of {332} 〈 113 〉 twinning mode in BCC alloys

Article using ab initio calculations and experimental observations to show that {332}<113> twinning can be described as a polymorphic solid-state transformation able to produce either twinned or martensitic structures with a unified transformation path.
Date: March 17, 2022
Creator: Kwasniak, P.; Sun, F.; Mantri, Srinivas Aditya; Banerjee, Rajarshi & Prima, Frederic
System: The UNT Digital Library
Effects of a Need-Supportive Motor Skill Intervention on Children’s Motor Skill Competence and Physical Activity (open access)

Effects of a Need-Supportive Motor Skill Intervention on Children’s Motor Skill Competence and Physical Activity

Study investigates the effect of a need-supportive fundamental movement skill (FMS) program on children’s FMS competence and moderate-to-vigorous physical activity (MVPA), and explores potential gender differences in these effects.
Date: March 17, 2020
Creator: Lee, Joonyoung; Zhang, Tao; Chu, Tsz Lun (Alan) & Gu, Xiangli
System: The UNT Digital Library
Improved Yield and Photosynthate Partitioning in AVP1 Expressing Wheat (Triticum aestivum) Plants (open access)

Improved Yield and Photosynthate Partitioning in AVP1 Expressing Wheat (Triticum aestivum) Plants

Article presents data consistent with the positive effect that the expression of the Arabidopsis thaliana H+-PPase (AVP1) has on reduced carbon partitioning and yield increases in wheat.
Date: March 17, 2020
Creator: Regmi, Kamesh C.; Yogendra, Kalenahalli; Gomes Farias, Júlia; Li, Lin; Kandel, Raju; Yadav, Umesh P. et al.
System: The UNT Digital Library
Confinement of antiprotons in the electrostatic space charge of positrons in a model of the ALPHA antihydrogen trap (open access)

Confinement of antiprotons in the electrostatic space charge of positrons in a model of the ALPHA antihydrogen trap

This article details the equilibrium of a positron plasma in a model of the ALPHA apparatus that is computed using a finite-difference method. The positron plasma in the model extends to axial magnetic mirrors in absence of an octupole field. Formation of a three-dimensional electrostatic potential well is found to occur self-consistently. Well depths under various conditions are evaluated. Also, the equilibrium with an antiproton plasma confined in the potential well is computed.
Date: March 17, 2016
Creator: Lane, Ryan A. & Ordonez, Carlos A.
System: The UNT Digital Library
Application of the Software as a Service Model to the Control of Complex Building Systems (open access)

Application of the Software as a Service Model to the Control of Complex Building Systems

In an effort to create broad access to its optimization software, Lawrence Berkeley National Laboratory (LBNL), in collaboration with the University of California at Davis (UC Davis) and OSISoft, has recently developed a Software as a Service (SaaS) Model for reducing energy costs, cutting peak power demand, and reducing carbon emissions for multipurpose buildings. UC Davis currently collects and stores energy usage data from buildings on its campus. Researchers at LBNL sought to demonstrate that a SaaS application architecture could be built on top of this data system to optimize the scheduling of electricity and heat delivery in the building. The SaaS interface, known as WebOpt, consists of two major parts: a) the investment&amp; planning and b) the operations module, which builds on the investment&amp; planning module. The operational scheduling and load shifting optimization models within the operations module use data from load prediction and electrical grid emissions models to create an optimal operating schedule for the next week, reducing peak electricity consumption while maintaining quality of energy services. LBNL's application also provides facility managers with suggested energy infrastructure investments for achieving their energy cost and emission goals based on historical data collected with OSISoft's system. This paper describes these …
Date: March 17, 2011
Creator: Stadler, Michael; Donadee, Jonathan; Marnay, Chris; Mendes, Goncalo; Appen, Jan von; Megel, Oliver et al.
System: The UNT Digital Library
The Dawn of Nuclear Photonics with Laser-based Gamma-rays (open access)

The Dawn of Nuclear Photonics with Laser-based Gamma-rays

A renaissance in nuclear physics is occurring around the world because of a new kind of incredibly bright, gamma-ray light source that can be created with short pulse lasers and energetic electron beams. These highly Mono-Energetic Gamma-ray (MEGa-ray) sources produce narrow, laser-like beams of incoherent, tunable gamma-rays and are enabling access and manipulation of the nucleus of the atom with photons or so called 'Nuclear Photonics'. Just as in the early days of the laser when photon manipulation of the valence electron structure of the atom became possible and enabling to new applications and science, nuclear photonics with laser-based gamma-ray sources promises both to open up wide areas of practical isotope-related, materials applications and to enable new discovery-class nuclear science. In the United States, the development of high brightness and high flux MEGa-ray sources is being actively pursued at the Lawrence Livermore National Laboratory in Livermore (LLNL), California near San Francisco. The LLNL work aims to create by 2013 a machine that will advance the state of the art with respect to source the peak brightness by 6 orders of magnitude. This machine will create beams of 1 to 2.3 MeV photons with color purity matching that of common lasers. …
Date: March 17, 2011
Creator: Barty, C J
System: The UNT Digital Library
Investigation of the Unoccupied Electronic Structure of UO2 with Bermstrahlung Isochromat Spectroscopy and X-Ray Absorption Spectroscopy (open access)

Investigation of the Unoccupied Electronic Structure of UO2 with Bermstrahlung Isochromat Spectroscopy and X-Ray Absorption Spectroscopy

UO{sub 2} is an important nuclear fuel for electrical power generation. Global goal : Actinides (5f electron systems) exhibit fascinating physical and chemical properties, due to 5f electron correlation, including the highly radioactive systems such as Pu. Onsite Instrumentation: A spectroscopic system containing spin resolved photoelectron spectroscopy (SRPES) and bremsstrahlung isochromat spectroscopy (BIS) has been built and commissioned at LLNL. ALS Instrumentation: The XAS was done on Beamline 8. Both Total Electron Yield (TEY) and Total Fluorescence Yield (TFY) were used. TFY is less surface sensitive than TEY. A combined experimental and theoretical study of Uranium Dioxide has been performed, including XAS, BIS, XPS and spectral simulations. The Conduction Bands or Unoccupied Density of States (UDOS) of UO{sub 2} are shown to be divided into two parts, the lower region being U5f-O2p and the upper region U6d-O2p. This means that UO{sub 2} is an f-f Mott Insulator, electron-correlated system. The keys to success with the XAS were the (1) the utilization of both TEY and TFY and (2) the accurate co-location of the uranium and oxygen states, which in turn hinged upon a proper calibration of the gratings of the beamline monochromator. The calibration of the gratings was greatly aided …
Date: March 17, 2011
Creator: Tobin, J. G.; Yu, S. W.; Crowhurst, J. C.; Sharma, S.; Dewhurst, J. K.; Olalde-Velasco, P. et al.
System: The UNT Digital Library
Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides (open access)

Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides

The subjects of discussion included: VUV photoelectron spectroscopy, X-ray photoelectron spectroscopy, Synchrotron-radiation-based photoelectron spectroscopy, Soft x-ray absorption spectroscopy, Soft x-ray emission spectroscopy, Inverse photoelectron spectroscopy, Bremstrahlung Isochromat Spectroscopy, Low energy IPES, Resonant inverse photoelectron spectroscopy.
Date: March 17, 2011
Creator: Tobin, J. G.
System: The UNT Digital Library
A Comparison of Three Voting Methods for Bagging with the MLEM2 Algorithm (open access)

A Comparison of Three Voting Methods for Bagging with the MLEM2 Algorithm

This paper presents results of experiments on some data sets using bagging on the MLEM2 rule induction algorithm. Three different methods of ensemble voting, based on support (a non-democratic voting in which ensembles vote with their strengths), strength only (an ensemble with the largest strength decides to which concept a case belongs) and democratic voting (each ensemble has at most one vote) were used. Our conclusions are that though in most cases democratic voting was the best, it is not significantly better than voting based on support. The strength voting was the worst voting method.
Date: March 17, 2010
Creator: Cohagan, Clinton; Grzymala-Busse, Jerzy W. & Hippe, Zdzislaw S.
System: The UNT Digital Library
Femtosecond isomerization dynamics in the ethylene cation measured in an EUV-pump NIR-probe configuration (open access)

Femtosecond isomerization dynamics in the ethylene cation measured in an EUV-pump NIR-probe configuration

Dynamics in the excited ethylene cation C{sub 2}H{sub 4}{sup +} lead to isomerization to the ethylidene configuration (HC-CH{sub 3}){sup +}, which is predicted to be a transient configuration for electronic relaxation. With an intense femtosecond EUV (extreme ultraviolet) pump pulse to populate the excited state, and an NIR (near infrared) probe pulse to produce the fragments CH{sup +} and CH{sub 3}{sup +} (which provides a direct signature of ethylidene), we measure optimum fragment yields at a probe delay of 80 fs. Also, an H{sub 2}-stretch transient configuration, yielding H{sub 2}{sup +} upon probing, is found to succeed the ethylidene configuration. We find that a simple single- or double-decay model does not match the data, and we present a modified model (introduction of an isomerization delay of 50 {+-} 25 fs) that does provide agreement.
Date: March 17, 2009
Creator: van Tilborg, Jeroen; Allison, Tom; Wright, Travis; Hertlein, Marc; Falcone, Roger; Liu, Yanwei et al.
System: The UNT Digital Library
Impact of Eliminating Mercury Removal Pretreatment on the Performance of a High Level Radioactive Waste Melter Offgas System (open access)

Impact of Eliminating Mercury Removal Pretreatment on the Performance of a High Level Radioactive Waste Melter Offgas System

The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: (1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; (2) adjust feed rheology; and (3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid pretreatment has been proposed to eliminate the production of hydrogen in the pretreatment systems; alternative reductants would be used to control redox. However, elimination of formic acid would result in significantly more mercury in the melter feed; the current specification is no more than 0.45 wt%, while the maximum expected prior to pretreatment is about 2.5 wt%. An engineering study has been undertaken to estimate the effects of eliminating mercury removal on the melter offgas system performance. A homogeneous gas-phase oxidation model …
Date: March 17, 2009
Creator: Zamecnik, J. & Alexander Choi, A.
System: The UNT Digital Library
Slow Hydrogen Transfer Reactions of Oxo- and Hydroxo-Vanadium Compounds: The Importance of Intrinsic Barriers (open access)

Slow Hydrogen Transfer Reactions of Oxo- and Hydroxo-Vanadium Compounds: The Importance of Intrinsic Barriers

Article on slow hydrogen atom transfer reactions of oxo- and hydroxo-vanadium compounds and the importance of intrinsic barriers.
Date: March 17, 2009
Creator: Waidmann, Christopher; Zhou, Xin; Tsai, Erin A.; Kaminsky, Werner; Hrovat, David A.; Borden, Weston T. et al.
System: The UNT Digital Library
Active Damping of the E-P Instability at the Los Alamos Proton Storage Ring (open access)

Active Damping of the E-P Instability at the Los Alamos Proton Storage Ring

A prototype of an analog, transverse (vertical) feedback system for active damping of the two-stream (e-p) instability has been developed and successfully tested at the Los Alamos Proton Storage Ring (PSR). This system was able to improve the instability threshold by approximately 30% (as measured by the change in RF buncher voltage at instability threshold). The feedback system configuration, setup procedures, and optimization of performance are described. Results of several experimental tests of system performance are presented including observations of instability threshold improvement and grow-damp experiments, which yield estimates of instability growth and damping rates. A major effort was undertaken to identify and study several factors limiting system performance. Evidence obtained from these tests suggests that performance of the prototype was limited by higher instability growth rates arising from beam leakage into the gap at lower RF buncher voltage and the onset of instability in the horizontal plane, which had no feedback.
Date: March 17, 2008
Creator: Macek, R. J.; Assadi, S.; Byrd, J. M.; Deibele, C. E.; Henderson, S. D.; Lee, S. Y. et al.
System: The UNT Digital Library
Beam Dynamics Studies for the SPARC Project (open access)

Beam Dynamics Studies for the SPARC Project

The aim of the SPARC project, is to promote an R&amp;D activity oriented to the development of a high brightness photoinjector to drive SASE-FEL experiments. We discuss in this paper the status of the beam dynamics simulation activities.
Date: March 17, 2008
Creator: Ferrario, M.; Biagini, Maria E.; Boscolo, M.; Fusco, V.; Guiducci, S.; Migliorati, M. et al.
System: The UNT Digital Library
A CCD Camera with Electron Decelerator for Intermediate Voltage Electron Microscopy (open access)

A CCD Camera with Electron Decelerator for Intermediate Voltage Electron Microscopy

Electron microscopists are increasingly turning to Intermediate Voltage Electron Microscopes (IVEMs) operating at 300 - 400 kV for a wide range of studies. They are also increasingly taking advantage of slow-scan charge coupled device (CCD) cameras, which have become widely used on electron microscopes. Under some conditions CCDs provide an improvement in data quality over photographic film, as well as the many advantages of direct digital readout. However, CCD performance is seriously degraded on IVEMs compared to the more conventional 100 kV microscopes. In order to increase the efficiency and quality of data recording on IVEMs, we have developed a CCD camera system in which the electrons are decelerated to below 100 kV before impacting the camera, resulting in greatly improved performance in both signal quality and resolution compared to other CCDs used in electron microscopy. These improvements will allow high-quality image and diffraction data to be collected directly with the CCD, enabling improvements in data collection for applications including high-resolution electron crystallography, single-particle reconstruction of protein structures, tomographic studies of cell ultrastructure and remote microscope operation. This approach will enable us to use even larger format CCD chips that are being developed with smaller pixels.
Date: March 17, 2008
Creator: Downing, Kenneth H; Downing, Kenneth H. & Mooney, Paul E.
System: The UNT Digital Library
Coupling Correction and Beam Dynamics at Ultralow Vertical Emittance in the ALS (open access)

Coupling Correction and Beam Dynamics at Ultralow Vertical Emittance in the ALS

For synchrotron light sources and for damping rings of linear colliders it is important to be able to minimize the vertical emittance and to correct the spurious vertical dispersion. This allows one to maximize the brightness and/or the luminosity. A commonly used tool to measure the skew error distribution is the analysis of orbit response matrices using codes like LOCO. Using the new Matlab version of LOCO and 18 newly installed power supplies for individual skew quadrupoles at the ALS the emittance ratio could be reduced below 0.1% at 1.9 GeV yielding a vertical emittance of about 5 pm. At those very low emittances, additional effects like intra beam scattering become more important, potentially limiting the minimum emittance for machine like the damping rings of linear colliders.
Date: March 17, 2008
Creator: Steier, Christoph; Robin, D.; Wolski, A.; Portmann, G.; Safranek, J. & /LBL, Berkeley /SLAC
System: The UNT Digital Library
DESIGN OF AN OPTICAL DIFFERACTION RADIATION BEAM SIZE MONITOR AT SLAC FETB (open access)

DESIGN OF AN OPTICAL DIFFERACTION RADIATION BEAM SIZE MONITOR AT SLAC FETB

We design a single bunch transverse beam size monitor which will be tested to measure the 28.5 GeV electron/positron beam at the SLAC FFTB beam line. The beam size monitor uses the CCD images of the interference pattern of the optical diffraction radiation from two slit edges which are placed close to the beam path. In this method, destruction of the accelerated electron/positron beam bunches due to the beam size monitoring is negligible, which is vital to the operation of the Linear Collider project.
Date: March 17, 2008
Creator: Fukui, Y.; Cline, D.; Zhou, F.; Tobiyama, M.; Urakawa, J.; Bolton, P. R. et al.
System: The UNT Digital Library
Digitral Down Conversion Technology for Tevatron Beam Line Tuner at FNAL (open access)

Digitral Down Conversion Technology for Tevatron Beam Line Tuner at FNAL

Fermilab is presently in Run II collider operations and is developing instrumentation to improve luminosity. Improving the orbit matching between accelerator components using a Beam Line Tuner (BLT) can improve the luminosity. Digital Down Conversion (DDC) has been proposed as a method for making more accurate beam position measurements. Fermilab has implemented a BLT system using a DDC technique to measure orbit oscillations during injections from the Main Injector to the Tevatron. The output of a fast ADC is downconverted and filtered in software. The system measures the x and y positions, the intensity, and the time of arrival for each proton or antiproton bunch, on a turn-by-turn basis, during the first 1024 turns immediately following injection. We present results showing position, intensity, and time of arrival for both injected and coasting beam. Initial results indicate a position resolution of {approx}20 to 40 microns and a phase resolution of {approx}25 ps.
Date: March 17, 2008
Creator: Schappert, W.; Lorman, E.; Scarpine, V.; Ross, M.C.; Sebek, J.; Straumann, T. et al.
System: The UNT Digital Library
Electron Cloud Generation and Trapping in a Quadrupole Magnet at the Los Alamos Proton Storage Ring (open access)

Electron Cloud Generation and Trapping in a Quadrupole Magnet at the Los Alamos Proton Storage Ring

Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the 'prompt' electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the 'swept' electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100 {micro}s. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the …
Date: March 17, 2008
Creator: Macek, Robert J.; Browman, Andrew A.; Ledford, John E.; Borden, Michael J.; O'Hara, James F.; McCrady, Rodney C. et al.
System: The UNT Digital Library
Electron Cloud Mitigation in the Spallation Neutron Source Ring (open access)

Electron Cloud Mitigation in the Spallation Neutron Source Ring

The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H{sup -} injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron-cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation.
Date: March 17, 2008
Creator: Wei, J.; Blaskiewicz, Michael; Brodowski, J.; Cameron, P.; Davino, Daniele; Fedotov, A. et al.
System: The UNT Digital Library
General Relativistic Effects in Atom Interferometry (open access)

General Relativistic Effects in Atom Interferometry

Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the non-relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this we develop a method for calculating the phase shift in general relativity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the non-linear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose experiments, one currently under construction, that could provide a test of the principle of equivalence to 1 part in 10{sup 15} (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the universe, and preferred frame and location effects.
Date: March 17, 2008
Creator: Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC /Stanford U., Phys. Dept.; Hogan, Jason M.; Kasevich, Mark A. et al.
System: The UNT Digital Library
A Lattice with Larger Momentum Compaction for the NLC Main Damping Rings (open access)

A Lattice with Larger Momentum Compaction for the NLC Main Damping Rings

Previous lattice designs for the Next Linear Collider Main Damping Rings [1] have met the specifications for equilibrium emittance, damping rate and dynamic aperture. Concerns about the effects of the damping wiggler on the beam dynamics [2] led to the aim of reducing the total length of the wiggler to a minimum consistent with the required damping rate, so high-field dipoles were used to provide a significant energy loss in the arcs. However, recent work has shown that the wiggler effects may not be as bad as previously feared. Furthermore, other studies have suggested the need for an increased momentum compaction (by roughly a factor of four) to raise the thresholds of various collective effects. We have therefore developed a new lattice design in which we increase the momentum compaction by reducing the field strength in the arc dipoles, compensating the loss in damping rate by increasing the length of the wiggler. The new lattice again meets the specifications for emittance, damping rate and dynamic aperture, while having the benefit of significantly higher thresholds for a number of instabilities.
Date: March 17, 2008
Creator: Woodley, M.; Raubenheimer, Tor O.; Wu, J.; Wolski, A. & /SLAC /LBL, Berkeley
System: The UNT Digital Library
Microbunching and Beam Break Up in DUV FEL Accelerator (open access)

Microbunching and Beam Break Up in DUV FEL Accelerator

We present the results of electron beam longitudinal modulation studies in the DUV-FEL accelerator. For bunch length determination we used the 'zero-phasing' method, based on a measurement of the chirped electron bunch energy spectra. The measurements revealed a spiky structure in the longitudinal phase space [1]. A model based on space charge effect is considered [2] to explain of the obtained phenomena. The analysis of the energy spectra has shown a sensitivity of the structure to the electron beam peak current, energy and longitudinal non-uniformity of the RF gun drive laser. Analytical calculations have demonstrated a qualitative agreement with experimental observations. Several experiments have been made to compare with theory; measured results are reviewed in this paper. The obtained effect is briefly discussed in relation to high brightness accelerators.
Date: March 17, 2008
Creator: Shaftan, T.; Carr, L.; Loos, H.; Sheehy, B.; Graves, William S.; Huang, Z. et al.
System: The UNT Digital Library