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The Value of Open Access to Undergraduate Research (open access)

The Value of Open Access to Undergraduate Research

Article describing the importance and value of open access to undergraduate research.
Date: October 1, 2013
Creator: Waugh, Laura & Keralis, Spencer D. C.
System: The UNT Digital Library
Social Capital and Self-Rated Health among Older Adults in China: A Multilevel Analysis (open access)

Social Capital and Self-Rated Health among Older Adults in China: A Multilevel Analysis

Article on social capital and self-rated health among middle-aged and older adults in China.
Date: October 7, 2013
Creator: Shen, Yuying; Yeatts, Dale E., 1952-; Cai, Tianji; Yang, Philip Q. & Cready, Cynthia M.
System: The UNT Digital Library
Cluster K Mycobacteriophages: Insights into the Evolutionary Origins of Mycobacteriophage TM4 (open access)

Cluster K Mycobacteriophages: Insights into the Evolutionary Origins of Mycobacteriophage TM4

Article on Cluster K mycobacteriophages and insights into the evolutionary origins of mycobacteriophage TM4.
Date: October 2011
Creator: Pope, Welkin H.; Ferreira, Christina M.; Jacobs-Sera, Deborah; Benjamin, Robert C.; Davis, Ariangela J.; DeJong, Randall J. et al.
System: The UNT Digital Library
A Network Control Theory Approach to Modeling and Optimal Control of Zoonoses: Case Study of Brucellosis Transmission in Sub-Saharan Africa (open access)

A Network Control Theory Approach to Modeling and Optimal Control of Zoonoses: Case Study of Brucellosis Transmission in Sub-Saharan Africa

Article on a network control theory approach to modeling and optimal control of zoonoses and a case study of brucellosis transmission in sub-Saharan Africa.
Date: October 2011
Creator: Roy, Sandip; McElwain, Terry F. & Wan, Yan
System: The UNT Digital Library
Crystal Structure of Thrombin in Complex with S-Variegin: Insights of a Novel Mechanism of Inhibition and Design of Tunable Thrombin Inhibitors (open access)

Crystal Structure of Thrombin in Complex with S-Variegin: Insights of a Novel Mechanism of Inhibition and Design of Tunable Thrombin Inhibitors

Article on the crystal structure of thrombin in complex with s-variegin and insights of a novel mechanism of inhibition and design of tunable thrombin inhibitors.
Date: October 2011
Creator: Koh, Cho Yeow; Kumar, Sundramurthy; Kazimirova, Maria; Nuttall, Patricia A.; Radhakrishnan, Uvaraj P.; Kim, Seongcheol et al.
System: The UNT Digital Library
Flavonoids and Isoflavonoids: From Plant Biology to Agriculture and Neuroscience (open access)

Flavonoids and Isoflavonoids: From Plant Biology to Agriculture and Neuroscience

This article discusses flavonoids and isoflavonoids from plant biology to agriculture to neuroscience.
Date: October 2010
Creator: Dixon, R. A. & Pasinetti, Giulio M.
System: The UNT Digital Library
Newton flow of the Riemann zeta function: separatrices control the appearance of zeros (open access)

Newton flow of the Riemann zeta function: separatrices control the appearance of zeros

This article applies the continuous Newton method to the Riemann zeta function and discusses the emerging patterns emphasizing especially the structuring of the non-trivial zeros by the separatrices.
Date: October 14, 2014
Creator: Neuberger, J. W.; Feiler, C.; Llopis, A.; Maier, H. & Schleich, W. P.
System: The UNT Digital Library
Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon) (open access)

Interspecific Differences in Metabolic Rate and Metabolic Temperature Sensitivity Create Distinct Thermal Ecological Niches in Lizards (Plestiodon)

This article examines three congeneric lizards from the southeastern United States (Plestiodon fasciatus, P. inexpectatus, and P. laticeps) and hypothesizes that interspecific differences in metabolic temperature sensitivity locally segregates them across their total range.
Date: October 19, 2016
Creator: Watson, Charles M. & Burggren, Warren W.
System: The UNT Digital Library
Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems (open access)

Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems

Prompt Gamma Neutron Activation (PGNAA) systems require the use of a gamma-ray spectrometer to record the gamma-ray spectrum of an object under test and allow the determination of the object’s composition. Field-portable systems, such as Idaho National Laboratory’s PINS system, have used standard liquid-nitrogen-cooled high-purity germanium (HPGe) detectors to perform this function. These detectors have performed very well in the past, but the requirement of liquid-nitrogen cooling limits their use to areas where liquid nitrogen is readily available or produced on-site. Also, having a relatively large volume of liquid nitrogen close to the detector can impact some assessments, possibly leading to a false detection of explosives or other nitrogen-containing chemical. Use of a mechanically-cooled HPGe detector is therefore very attractive for PGNAA applications where nitrogen detection is critical or where liquid-nitrogen logistics are problematic. Mechanically-cooled HPGe detectors constructed from p-type germanium, such as Ortec’s trans-SPEC, have been commercially available for several years. In order to assess whether these detectors would be suitable for use in a fielded PGNAA system, Idaho National Laboratory (INL) has been performing a number of tests of the resistance of mechanically-cooled HPGe detectors to neutron damage. These detectors have been standard commercially-available p-type HPGe detectors as …
Date: October 1, 2013
Creator: Seabury, E. H.; Wharton, C. J.; Caffrey, A. J.; McCabe, J. B. & Van Siclen, C. Dew.
System: The UNT Digital Library
An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW—AAPL Automatic Anharmonic Phonon Library (open access)

An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW—AAPL Automatic Anharmonic Phonon Library

This article presents the Automatic Anharmonic Phonon Library.
Date: November 17, 2016
Creator: Plata, Jose J.; Nath, Pinku; Usanmaz, Demet; Carrete, Jesús; Toher, Cormac; de Jong, Maarten et al.
System: The UNT Digital Library
[Review] Story of Space, The (open access)

[Review] Story of Space, The

This column reviews the book "The Story of Space" by Catherine Barr and Steve Williams for inclusion in school libraries. This review includes recommendations for teachers, content subjects, and a recommended grade level.
Date: October 1, 2017
Creator: Monahan, Jo
System: The UNT Digital Library
[Review] Boris and the Worrisome Wakies (open access)

[Review] Boris and the Worrisome Wakies

This column reviews the book "Boris and the Worrisome Wakies" by Helen Lester for inclusion in school libraries. This review includes recommendations for teachers, content subjects, and a recommended grade level.
Date: October 1, 2017
Creator: Monahan, Jo
System: The UNT Digital Library
[Review] Eat Up! An Infographic Exploration of Food (open access)

[Review] Eat Up! An Infographic Exploration of Food

This column reviews the book "Eat Up! An Infographic Exploration of Food" by Nancy Tupper Ling for inclusion in school libraries. This review includes recommendations for teachers, content subjects, and a recommended grade level.
Date: October 1, 2017
Creator: Monahan, Jo
System: The UNT Digital Library
[Review] Private Space Travel (open access)

[Review] Private Space Travel

This column reviews the book "Private Space Travel" for inclusion in school libraries. This review includes recommendations for teachers, content subjects, and a recommended grade level.
Date: October 1, 2017
Creator: Monahan, Jo
System: The UNT Digital Library
[Review] Albert Helps Out (open access)

[Review] Albert Helps Out

This column reviews the book "Albert Helps Out" by Eleano May for inclusion in school libraries. This review includes recommendations for teachers, content subjects, and a recommended grade level.
Date: October 1, 2017
Creator: Monahan, Jo
System: The UNT Digital Library
Neutrino physics today, important issues and the future (open access)

Neutrino physics today, important issues and the future

The status and the most important issues in neutrino physics will be summarized as well as how the current, pressing questions will be addressed by future experiments. Since the discovery of neutrino flavor transitions by the SuperKamiokande experiment in 1998, which demonstrates that neutrinos change and hence their clocks tick, i.e. they are not traveling at the speed of light and hence are not massless, the field of neutrino physics has made remarkable progress in untangling the nature of the neutrino. However, there are still many important questions to answer.
Date: October 1, 2010
Creator: Parke, Stephen J.
System: The UNT Digital Library
An Assessment of Molecular Dynamic Force Fields for Silica for Use in Simulating Laser Damage Mitigation (open access)

An Assessment of Molecular Dynamic Force Fields for Silica for Use in Simulating Laser Damage Mitigation

We compare force fields (FF's) that have been used in molecular dynamic (MD) simulations of silica in order to assess their applicability for use in simulating IR-laser damage mitigation. Although pairwise FF?s obtained by fitting quantum mechanical calculations such as the BKS and CHIK potentials have been shown to reproduce many of the properties of silica including the stability of silica polymorphs and the densification of the liquid, we show that melting temperatures and fictive temperatures are much too high. Softer empirical force fields give liquid and glass properties at experimental temperatures but may not predict all properties important to laser mitigation experiments.
Date: October 21, 2010
Creator: Soules, T F; Gilmer, G H; Matthews, M J; Stolken, J S & Feit, M D
System: The UNT Digital Library
Development and Test of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades. (open access)

Development and Test of a Single-Aperture 11 T Nb3Sn Demonstrator Dipole for LHC Upgrades.

The upgrade of the LHC collimation system expects installation of additional collimators in the dispersion suppressor areas around the LHC ring. The longitudinal space for the collimators could be provided by replacing some 8.33 T Nb-Ti LHC main dipoles with shorter 11 T Nb/sub 3/Sn dipoles compatible with the LHC lattice and main systems. To demonstrate this possibility FNAL and CERN have started a joint program with the goal of building a 5.5 m long twin-aperture dipole prototype suitable for installation in the LHC. The first step of this program is the development of a 2 m long single-aperture demonstrator dipole with the nominal field of 11 T at the LHC nominal current of 11.85 kA and 60 mm bore with ~20% margin. This paper describes the design, construction and test results of the first single-aperture Nb/sub 3/Sn demonstrator dipole model.
Date: October 1, 2012
Creator: Zlobin, A.V. & al., et
System: The UNT Digital Library
Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX) (open access)

Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX)

We report results on lithium alumino-silicate ion source development in preparation for warmdense-matter heating experiments on the new Neutralized Drift Compression Experiment (NDCXII). The practical limit to the current density for a lithium alumino-silicate source is determined by the maximum operating temperature that the ion source can withstand before running into problems of heat transfer, melting of the alumino-silicate material, and emission lifetime. Using small prototype emitters, at a temperature of ~;;1275 oC, a space-charge-limited Li+ beam current density of J ~;;1 mA/cm2 was obtained. The lifetime of the ion source was ~;;50 hours while pulsing at a rate of 0.033 Hz with a pulse duration of 5-6 mu s.
Date: October 1, 2010
Creator: Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W.; Seidl, Peter A.; Waldron, William L. & Wu, James K.
System: The UNT Digital Library
Efficiency Enhancement in a Tapered Free Electron Laser By Varying the Electron Beam Radius (open access)

Efficiency Enhancement in a Tapered Free Electron Laser By Varying the Electron Beam Radius

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Date: October 8, 2013
Creator: Jiao, Y.; Wu, J. & Qin, Q.
System: The UNT Digital Library
Halo Formation And Emittance Growth of Positron Beams in Plasmas (open access)

Halo Formation And Emittance Growth of Positron Beams in Plasmas

An ultrarelativistic 28.5 GeV, 700-{micro}m-long positron bunch is focused near the entrance of a 1.4-m-long plasma with a density n{sub e} between {approx}10{sup 13} and {approx}5 x 10{sup 14} cm{sup -3}. Partial neutralization of the bunch space charge by the mobile plasma electrons results in a reduction in transverse size by a factor of {approx}3 in the high emittance plane of the beam {approx}1 m downstream from the plasma exit. As n{sub e} increases, the formation of a beam halo containing {approx}40% of the total charge is observed, indicating that the plasma focusing force is nonlinear. Numerical simulations confirm these observations. The bunch with an incoming transverse size ratio of {approx}3 and emittance ratio of {approx}5 suffers emittance growth and exits the plasma with approximately equal sizes and emittances.
Date: October 25, 2011
Creator: Muggli, P.; Blue, B. E.; Clayton, C. E.; Decker, F. J.; Hogan, M. J.; Huang, C. et al.
System: The UNT Digital Library
A truncated Levenberg-Marquardt algorithm for the calibration of highly parameterized nonlinear models (open access)

A truncated Levenberg-Marquardt algorithm for the calibration of highly parameterized nonlinear models

We propose a modification to the Levenberg-Marquardt minimization algorithm for a more robust and more efficient calibration of highly parameterized, strongly nonlinear models of multiphase flow through porous media. The new method combines the advantages of truncated singular value decomposition with those of the classical Levenberg-Marquardt algorithm, thus enabling a more robust solution of underdetermined inverse problems with complex relations between the parameters to be estimated and the observable state variables used for calibration. The truncation limit separating the solution space from the calibration null space is re-evaluated during the iterative calibration process. In between these re-evaluations, fewer forward simulations are required, compared to the standard approach, to calculate the approximate sensitivity matrix. Truncated singular values are used to calculate the Levenberg-Marquardt parameter updates, ensuring that safe small steps along the steepest-descent direction are taken for highly correlated parameters of low sensitivity, whereas efficient quasi-Gauss-Newton steps are taken for independent parameters with high impact. The performance of the proposed scheme is demonstrated for a synthetic data set representing infiltration into a partially saturated, heterogeneous soil, where hydrogeological, petrophysical, and geostatistical parameters are estimated based on the joint inversion of hydrological and geophysical data.
Date: October 15, 2010
Creator: Finsterle, S. & Kowalsky, M.B.
System: The UNT Digital Library
Performance Validation and Scaling of a Capillary Membrane Solid-Liquid Separation System (open access)

Performance Validation and Scaling of a Capillary Membrane Solid-Liquid Separation System

Algaeventure Systems (AVS) has previously demonstrated an innovative technology for dewatering algae slurries that dramatically reduces energy consumption by utilizing surface physics and capillary action. Funded by a $6M ARPA-E award, transforming the original Harvesting, Dewatering and Drying (HDD) prototype machine into a commercially viable technology has required significant attention to material performance, integration of sensors and control systems, and especially addressing scaling issues that would allow processing extreme volumes of algal cultivation media/slurry. Decoupling the harvesting, dewatering and drying processes, and addressing the rate limiting steps for each of the individual steps has allowed for the development individual technologies that may be tailored to the specific needs of various cultivation systems. The primary performance metric used by AVS to assess the economic viability of its Solid-Liquid Separation (SLS) dewatering technology is algae mass production rate as a function of power consumption (cost), cake solids/moisture content, and solids capture efficiency. An associated secondary performance metric is algae mass loading rate which is dependent on hydraulic loading rate, area-specific hydraulic processing capacity (gpm/in2), filter:capillary belt contact area, and influent algae concentration. The system is capable of dewatering 4 g/L (0.4%) algae streams to solids concentrations up to 30% with capture efficiencies …
Date: October 25, 2011
Creator: Rogers, S.; Cook, J.; Juratovac, J.; Goodwillie, J.; Burke, T. & Stuart, B., ed.
System: The UNT Digital Library
Large Synoptic Survey Telescope: From Science Drivers to Reference Design (open access)

Large Synoptic Survey Telescope: From Science Drivers to Reference Design

In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image …
Date: October 14, 2011
Creator: Ivezic, Z.; Axelrod, T.; Brandt, W. N.; Burke, D. L.; Claver, C. F.; Connolly, A. et al.
System: The UNT Digital Library