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Evaluation of Climate Change Impacts on Wetland Vegetation in the Dunhuang Yangguan National Nature Reserve in Northwest China Using Landsat Derived NDVI

Description: This article uses 41 Landsat images between 1988 and 2016 to calculate the normalized difference vegetation indices (NVDIs) of the wetland vegetation at Xitugou (XTG) and Wowachi (WWC) inside the Dunhuang Yangguan National Nature Reserve in northwest China in order to assess the impacts of climate change on wetland vegetation.
Date: May 10, 2018
Creator: Pan, Feifei; Xie, Jianping; Lin, Juming; Zhao, Tingwei; Ji, Yongyuan; Hu, Qi et al.
Partner: UNT College of Liberal Arts & Social Sciences
open access

Identity Management at the University of North Texas

Description: Brief history of name authority in the University of North Texas (UNT) Libraries' Digital Collections, including the development and use of a local name authority database for creators associated with the UNT community. This text was part of the article "Who Is This: Moving from Authority Control to Identity Management" published in the May/June 2018 issue of AALL Spectrum.
Date: May 2018
Creator: Tarver, Hannah
Partner: UNT Libraries Digital Projects Unit
open access

Reversible Electron Beam Heating for Suppression of Micro bunching Instabilities at Free-Electron Lasers

Description: The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future x-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., heating the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light So… more
Date: May 30, 2012
Creator: Behrens, Christopher; Huang, Zhirong & Xiang, Dao
Partner: UNT Libraries Government Documents Department
open access

Raman Spectroscopy of UH3 from the Hydrogen Corrosion of Uranium

Description: Hydrogen reacts with a uranium surface to form a fine, pyrophoric metal power (UH{sub 3}). Few spectroscopic studies have been conducted to study this reaction. Advances in Raman spectroscopy permit the application of the Raman method to formally difficult areas of chemistry such as the hydrogen corrosion of uranium: availability of multiple laser excitation wavelengths; fiber optics delivery and collection systems; upgraded instrumentation and detection techniques; and development of special e… more
Date: May 31, 2011
Creator: Smyrl, N. R.; Stowe, A. C. & Powell, G. L.
Partner: UNT Libraries Government Documents Department
open access

New Particle-in-Cell Code for Numerical Simulation of Coherent Synchrotron Radiation

Description: We present a first look at the new code for self-consistent, 2D simulations of beam dynamics affected by the coherent synchrotron radiation. The code is of the particle-in-cell variety: the beam bunch is sampled by point-charge particles, which are deposited on the grid; the corresponding forces on the grid are then computed using retarded potentials according to causality, and interpolated so as to advance the particles in time. The retarded potentials are evaluated by integrating over the 2D … more
Date: May 1, 2010
Creator: Balsa Terzic, Rui Li
Partner: UNT Libraries Government Documents Department
open access

BEAM CONTAINMENT SYSTEM FOR NSLS-II

Description: The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indicatio… more
Date: May 23, 2010
Creator: Kramer, S. L.; Casey, W. & Job, P. K.
Partner: UNT Libraries Government Documents Department
open access

Requirements for Computer Based-Procedures for Nuclear Power Plant Field Operators Results from a Qualitative Study

Description: Although computer-based procedures (CBPs) have been investigated as a way to enhance operator performance on procedural tasks in the nuclear industry for almost thirty years, they are not currently widely deployed at United States utilities. One of the barriers to the wide scale deployment of CBPs is the lack of operational experience with CBPs that could serve as a sound basis for justifying the use of CBPs for nuclear utilities. Utilities are hesitant to adopt CBPs because of concern over pot… more
Date: May 1, 2012
Creator: Blanc, Katya Le & Oxstrand, Johanna
Partner: UNT Libraries Government Documents Department
open access

Design and Simulation of IOTA - a Novel Concept of Integrable Optics Test Accelerator

Description: The use of nonlinear lattices with large betatron tune spreads can increase instability and space charge thresholds due to improved Landau damping. Unfortunately, the majority of nonlinear accelerator lattices turn out to be nonintegrable, producing chaotic motion and a complex network of stable and unstable resonances. Recent advances in finding the integrable nonlinear accelerator lattices have led to a proposal to construct at Fermilab a test accelerator with strong nonlinear focusing which … more
Date: May 1, 2012
Creator: Nagaitsev, S.; Valishev, A.; /Fermilab; Danilov, V.V.; Ridge, /Oak; Shatilov, D.N. et al.
Partner: UNT Libraries Government Documents Department
open access

Shielding of a hadron in a finite e-beam

Description: The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - … more
Date: May 20, 2012
Creator: A., Elizarov; Litvinenko, V. & Wang, G.
Partner: UNT Libraries Government Documents Department
open access

Density Functional Theory in Surface Chemistry and Catalysis

Description: 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
Partner: UNT Libraries Government Documents Department
open access

Simulation and Experiment of Thermal Fatigue in the CPV Die Attach: Preprint

Description: FEM simulation and accelerated thermal cycling have been performed for the CPV die attach. Trends in fatigue damage accumulation and equivalent test time are explored and found to be most sensitive to temperature ramp rate. Die attach crack growth is measured through cycling and found to be in excellent agreement with simulations of the inelastic strain energy accumulated. Simulations of an entire year of weather data provides for the relative ranking of fatigue damage between four cites as wel… more
Date: May 1, 2012
Creator: Bosco, N.; Silverman, T. & Kurtz, S.
Partner: UNT Libraries Government Documents Department
open access

Novel Geometries for the LHC Crab Cavity

Description: The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the I… more
Date: May 23, 2010
Creator: B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang
Partner: UNT Libraries Government Documents Department
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