Hostage-Taking Statute Covers Kidnapping for Ransom Abroad (open access)

Hostage-Taking Statute Covers Kidnapping for Ransom Abroad

This report discusses the U.S. Court of Appeals case United States v. Noel, in which Noel challenged his conviction for seizing an American citizen in Haiti to hold for ransom.
Date: July 30, 2018
Creator: Doyle, Charles
Object Type: Report
System: The UNT Digital Library
China-U.S. Trade Issues (open access)

China-U.S. Trade Issues

This report provides an overview of U.S.-China commercial ties, identifies major issues of contention, describes the Trump Administration's trade policies toward China, and reviews possible outcomes.
Date: July 30, 2018
Creator: Morrison, Wayne M.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: GA-1072 (open access)

Texas Attorney General Opinion: GA-1072

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Whether a taxing unit may reserve mineral interests on property that is acquired through tax foreclosure and then resold pursuant to section 34.05 ofthe Tax Code (RQ-1182-GA).
Date: July 30, 2014
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Enhancing FEL Power with Phase Shifters (open access)

Enhancing FEL Power with Phase Shifters

Tapering the undulator parameter is a well-known method for maintaining the resonant condition past saturation, and increasing Free Electron Laser (FEL) efficiency. In this paper, we demonstrate that shifting the electron bunch phase relative to the radiation is equivalent to tapering the undulator parameter. Using discrete phase changes derived from optimized undulator tapers for the Linac Coherent Light Source (LCLS) x-ray FEL, we show that appropriate phase shifts between undulator sections can reproduce the power enhancement of undulator tapers. Phase shifters are relatively easy to implement and operate, and could be used to aid or replace undulator tapers in optimizing FEL performance.
Date: July 30, 2010
Creator: Ratner, Daniel; Chao, Alex & Huang, Zhirong
Object Type: Article
System: The UNT Digital Library
Two-Chicane Compressed Harmonic Generation of Soft X-Rays (open access)

Two-Chicane Compressed Harmonic Generation of Soft X-Rays

We propose a simple single-stage scheme to produce fully coherent 3nm radiation. Seeding an electron bunch prior to compression simultaneously shortens the laser wavelength and duration, and increases the modulation amplitude. The final X-ray wavelength is tunable by controlling the compression factor with the RF phase. We propose a two chicane scheme that allows for nearly arbitrary modulation amplitudes, extending the method to photocathode beams. We also show that transportation of fine compressed modulation structure is feasible due to a canceling effect of the second chicane.
Date: July 30, 2010
Creator: Ratner, Daniel; Huang, Z. & Chao, A.
Object Type: Article
System: The UNT Digital Library
Threshold Studies of the Microwave Instability in Electron Storage Rings (open access)

Threshold Studies of the Microwave Instability in Electron Storage Rings

We use a Vlasov-Fokker-Planck program and a linearized Vlasov solver to study the microwave instability threshold of impedance models: (1) a Q = 1 resonator and (2) shielded coherent synchrotron radiation (CSR), and find the results of the two programs agree well. For shielded CSR we show that only two dimensionless parameters, the shielding parameter {Pi} and the strength parameter S{sub csr}, are needed to describe the system. We further show that there is a strong instability associated with CSR, and that the threshold, to good approximation, is given by (S{sub csr})th = 0.5 + 0.12{Pi}. In particular, this means that shielding has little effect in stabilizing the beam for {Pi} {approx}< 2; for larger {Pi} it is effective, with threshold current depending on shielding aperture as h{sup -3/2}. We, in addition, find another instability in the vicinity of {Pi} = 0.7 with a lower threshold, (S{sub csr}){sub th} {approx} 0.2. We find that the threshold to this instability depends strongly on damping time, (S{sub csr}){sub th} {approx} {tau}{sub p}{sup -1/2}, and that the tune spread at threshold is small - both hallmarks of a weak instability.
Date: July 30, 2010
Creator: Bane, K. L. F.; Cai, Y. & Stupakov, G.
Object Type: Article
System: The UNT Digital Library
Air and Radon Pathway Modeling for the F Area Tank Farm (open access)

Air and Radon Pathway Modeling for the F Area Tank Farm

An air and radon pathways analysis was conducted for the F-Area Tank Farm (FTF) to estimate the flux of volatile radionuclides and radon at the ground surface due to residual waste remaining in the tanks following closure. This analysis was used as the basis to estimate the dose to the maximally exposed individual (MEI) for the air pathway per Curie (Ci) of each radionuclide remaining in the combined FTF waste tanks. For the air pathway analysis, several gaseous radionuclides were considered. These included carbon-14 (C-14), chlorine-36 (Cl-36), iodine-129 (I-129), selenium-79 (Se-79), antimony-125 (Sb-125), tin-126 (Sn-126), tritium (H-3), and technetium-99 (Tc-99). The dose to the MEI was estimated at the SRS Boundary during the 100 year institutional control period. For the 10,000 year post closure compliance period, the dose to the MEI was estimated at the 100 m compliance point. Additionally, the dose to the MEI was estimated at a seepage outcrop located 1600 m from the facility. For the radon pathway analysis, five parent radionuclides and their progeny were analyzed. These parent radionuclides included uranium-238 (U-238), plutonium-238 (Pu-238), uranium-234 (U-234), thorium-230 (Th-230), and radium-226 (Ra-226). The peak flux of radon-222 due to each parent radionuclide was estimated for the simulation …
Date: July 30, 2010
Creator: Dixon, K. & Phifer, M.
Object Type: Report
System: The UNT Digital Library
Carrier hopping in disordered semiconducting polymers: How accurate is the Miller-Abrahams model? (open access)

Carrier hopping in disordered semiconducting polymers: How accurate is the Miller-Abrahams model?

We performed direct calculations of carrier hopping rates in strongly disordered conjugated polymers based on the atomic structure of the system, the corresponding electronic states and their coupling to all phonon modes. We found that the dependence of hopping rates on distance and the dependence of the mobility on temperature are significantly different than the ones stemming from the simple Miller-Abrahams model, regardless of the choice of the parameters in the model. A model that satisfactorily describes the hopping rates in the system and avoids the explicit calculation of electron-phonon coupling constants was then proposed and verified. Our results indicate that, in addition to electronic density of states, the phonon density of states and the spatial overlap of the wavefunctions are the quantities necessary to properly describe carrier hopping in disordered conjugated polymers.
Date: July 30, 2010
Creator: Vukmirovic, Nenad & Wang, Lin-Wang
Object Type: Article
System: The UNT Digital Library
The Study of Single Nb3Sn Quadrupole Coils Using a Magnetic Mirror Structure (open access)

The Study of Single Nb3Sn Quadrupole Coils Using a Magnetic Mirror Structure

Several 90-mm quadrupole coils made of 0.7-mm Nb{sub 3}Sn strand based on the 'Restack Rod Process' (RRP) of 108/127 design, with cored and non-cored cables and different cable insulation, were fabricated and individually tested at Fermilab using a test structure designed to provide a quadrupole magnetic field environment. The coils were instrumented with voltage taps and strain gauges to study quench performance and mechanical properties. The Nb{sub 3}Sn strand and cable parameters, the coil fabrication details, the mirror model assembly procedure and test results at temperatures of 4.5 K and 1.9 K are reported and discussed.
Date: July 30, 2010
Creator: Chlachidze, G.; Andreev, N.; Barzi, E.; Bossert, R.; Kashikhin, V. S.; Kashikhin, V. V. et al.
Object Type: Article
System: The UNT Digital Library
Intelligent Component Monitoring for Nuclear Power Plants (open access)

Intelligent Component Monitoring for Nuclear Power Plants

Reliability and economy are two major concerns for a nuclear power generation system. Next generation nuclear power reactors are being developed to be more reliable and economic. An effective and efficient surveillance system can generously contribute toward this goal. Recent progress in computer systems and computational tools has made it necessary and possible to upgrade current surveillance/monitoring strategy for better performance. For example, intelligent computing techniques can be applied to develop algorithm that help people better understand the information collected from sensors and thus reduce human error to a new low level. Incidents incurred from human error in nuclear industry are not rare and have been proven costly. The goal of this project is to develop and test an intelligent prognostics methodology for predicting aging effects impacting long-term performance of nuclear components and systems. The approach is particularly suitable for predicting the performance of nuclear reactor systems which have low failure probabilities (e.g., less than 10-6 year-). Such components and systems are often perceived as peripheral to the reactor and are left somewhat unattended. That is, even when inspected, if they are not perceived to be causing some immediate problem, they may not be paid due attention. Attention to such …
Date: July 30, 2010
Creator: Tsoukalas, Lefteri
Object Type: Report
System: The UNT Digital Library
New Fission-Product Waste Forms:  Development and Characterization (open access)

New Fission-Product Waste Forms: Development and Characterization

Research performed on the program “New Fission Product Waste Forms: Development and Characterization,” in the last three years has fulfilled the objectives of the proposal which were to 1) establish ceramic waste forms for disposing of Cs, Sr and minor actinides, 2) fully characterize the phase relationships, structures and thermodynamic and kinetic stabilities of promising waste forms, 3) establish a sound technical basis for understanding key waste form properties, such as melting temperatures and aqueous durability, based on an in-depth understanding of waste form structures and thermochemistry, and 4) establish synthesis, testing, scaleup and commercialization routes for wasteform implementation through out in-kind collaborations. In addition, since Cs and Sr form new elements by radioactive decay, the behavior and thermodynamics of waste forms containing different proportions of Cs, Sr and their decay products were discovered using non-radioactive analogues. Collaborations among researchers from three institutions, UC Davis, Sandia National Laboratories, and Shott Inc., were formed to perform the primary work on the program. The unique expertise of each of the members in the areas of waste form development, structure/property relationships, hydrothermal and high temperature synthesis, crystal/glass production, and thermochemistry was critical to program success. In addition, collaborations with the Brigham Young Univeristy, …
Date: July 30, 2010
Creator: Navrotsky, Alexandra
Object Type: Report
System: The UNT Digital Library
The Hydrogeologic Character of the Lower Tuff Confining Unit and the Oak Springs Butte Confining Unit in the Tuff Pile Area of Central Yucca Flat (open access)

The Hydrogeologic Character of the Lower Tuff Confining Unit and the Oak Springs Butte Confining Unit in the Tuff Pile Area of Central Yucca Flat

The lower tuff confining unit (LTCU) in the Yucca Flat Corrective Action Unit (CAU) consists of a monotonous sequence of pervasively zeolitized volcanic tuff (i.e., mostly bedded with lesser nonwelded to poorly welded tuff; not fractured) (Bechtel Nevada, 2006). The LTCU is an important confining unit beneath Yucca Flat because it separates the alluvial and volcanic aquifers, where many underground nuclear tests were conducted, from the regional lower carbonate aquifer. Recent sub-CAU-scale modeling by Los Alamos National Laboratory in the Tuff Pile area of Yucca Flat (Boryta, et al., in review) includes postulated low-porosity, high-permeability zones (i.e., fractured welded-tuff aquifers) within the LTCU. This scenario indicates that such postulated low-porosity, high-permeability zones could provide fast-path lateral conduits to faults, and eventually to the lower carbonate aquifer. A fractured and faulted lower carbonate aquifer is postulated to provide a flow path(s) for underground test-derived contaminants to potential offsite receptors. The ramifications of such a scenario are obvious for groundwater flow and contaminant migration beneath Yucca Flat. This paper describes the reasoning for not including postulated low-porosity, high-permeability zones within the LTCU in the Tuff Pile area or within the LTCU in the Yucca Flat CAU-scale model. Both observational and analytical data …
Date: July 30, 2010
Creator: Sigmund L. Drellack, Jr., Lance B. Prothro, Jose L. Gonzales, and Jennifer M. Mercadante
Object Type: Report
System: The UNT Digital Library
Water management technologies used by Marcellus Shale Gas Producers. (open access)

Water management technologies used by Marcellus Shale Gas Producers.

Natural gas represents an important energy source for the United States. According to the U.S. Department of Energy's (DOE's) Energy Information Administration (EIA), about 22% of the country's energy needs are provided by natural gas. Historically, natural gas was produced from conventional vertical wells drilled into porous hydrocarbon-containing formations. During the past decade, operators have increasingly looked to other unconventional sources of natural gas, such as coal bed methane, tight gas sands, and gas shales.
Date: July 30, 2010
Creator: Veil, J. A. & Division, Environmental Science
Object Type: Report
System: The UNT Digital Library
Design of Helical Cooling Channel for Muon Collider (open access)

Design of Helical Cooling Channel for Muon Collider

Fast muon beam six dimensional (6D) phase space cooling is essential for muon colliders. The Helical Cooling Channel (HCC) uses hydrogen-pressurized RF cavities imbedded in a magnet system with solenoid, helical dipole, and helical quadrupole components that provide the continuous dispersion needed for emittance exchange and effective 6D beam cooling. A series of HCC segments, each with sequentially smaller aperture, higher magnetic field, and higher RF frequency to match the beam size as it is cooled, has been optimized by numerical simulation to achieve a factor of 10{sup 5} emittance reduction in a 300 m long channel with only a 40% loss of beam. Conceptual designs of the hardware required for this HCC system and the status of the RF studies and HTS helical solenoid magnet prototypes are described.
Date: July 30, 2010
Creator: Yonehara, Katsuya
Object Type: Article
System: The UNT Digital Library
Developmemt, Characterization, Production, and Demonstration of Nanofluids for Industrial Cooling Applications. Quarterly Report #7. (open access)

Developmemt, Characterization, Production, and Demonstration of Nanofluids for Industrial Cooling Applications. Quarterly Report #7.

Pumping power measurements have been made on a series of 40-nm boehmite (AlOOH) alumina ''bricks'' (2 - 8 vol. percent in water). The alumina nanoparticles were obtained from Sasol and are designated as ''Catapal-200''. The pH of all compositions was adjusted to 3.2{+-}0.5. A complete characterization of the particles and their nanofluid thermal properties has been published in Journal of Applied Physics 106, 014304 (2009). While the nanofluid doesn't show large enhancements, it nevertheless serves as good comparisons between the experimental results and calculated results.
Date: July 30, 2010
Creator: Routbort, J.; Singh, D.; Timofeeva, E.; Yu, W. & France, D.
Object Type: Report
System: The UNT Digital Library
FEL Gain Length and Taper Measurements at LCLS (open access)

FEL Gain Length and Taper Measurements at LCLS

We present experimental studies of the gain length and saturation power level from 1.5 nm to 1.5 {angstrom} at the Linac Coherent Light Source (LCLS). By disrupting the FEL process with an orbit kick, we are able to measure the X-ray intensity as a function of undulator length. This kick method is cross-checked with the method of removing undulator sections. We also study the FEL-induced electron energy loss after saturation to determine the optimal taper of the undulator K values. The experimental results are compared to theory and simulations.
Date: July 30, 2010
Creator: Ratner, Daniel; Brachmann, A.; Decker, F. J.; Ding, Y.; Dowell, D.; Emma, P. et al.
Object Type: Article
System: The UNT Digital Library
Accelerator-Based Irradiation Creep of Pyrolytic Carbon Used in TRISO Fuel Particles for the (VHTR) Very Hight Temperature Reactors (open access)

Accelerator-Based Irradiation Creep of Pyrolytic Carbon Used in TRISO Fuel Particles for the (VHTR) Very Hight Temperature Reactors

Pyrolytic carbon (PyC) is one of the important structural materials in the TRISO fuel particles which will be used in the next generation of gas-cooled very-high-temperature reactors (VHTR). When the TRISO particles are under irradiation at high temperatures, creep of the PyC layers may cause radial cracking leading to catastrophic particle failure. Therefore, a fundamental understanding of the creep behavior of PyC during irradiation is required to predict the overall fuel performance.
Date: July 30, 2010
Creator: Wang, Lumin & Was, Gary
Object Type: Report
System: The UNT Digital Library
Observation of the Rare Decay B0 to K0(s)K+-pi-+ (open access)

Observation of the Rare Decay B0 to K0(s)K+-pi-+

We report an analysis of charmless hadronic decays of neutral B mesons to the final state K{sub S}{sup 0}K{sup {+-}}{pi}{sup {-+}}, using a data sample of (465 {+-} 5) x 10{sup 6} B{bar B} events collected with the BABAR detector at the {Upsilon}(4S) resonance. We observe an excess of signal events with a significance of 5.2 standard deviations including systematic uncertainties and measure the branching fraction to be {Beta}(B{sup 0} {yields} K{sub S}{sup 0}K{sup {+-}}{pi}{sup {-+}}) = (3.2 {+-} 0.5 {+-} 0.3) x 10{sup -6}, where the uncertainties are statistical and systematic, respectively.
Date: July 30, 2010
Creator: del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J. et al.
Object Type: Article
System: The UNT Digital Library
Search for fj(2220) in radiative J/psi decays (open access)

Search for fj(2220) in radiative J/psi decays

We present a search for f{sub J}(2220) production in radiative J/{psi} {yields} {gamma}f{sub J}(2220) decays using 460 fb{sup -1} of data collected with the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} collider. The f{sub J}(2220) is searched for in the decays to K{sup +}K{sup -} and K{sub S}{sup 0}K{sub S}{sup 0}. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/{psi} {yields} {gamma}f{sub J}(2220) and f{sub J}(2220) {yields} K{sup +}K{sup -}(K{sub S}{sup 0}K{sub S}{sup 0}) as a function of spin and helicity are set at the level of 10{sup -5}, below the central values reported by the Mark III experiment.
Date: July 30, 2010
Creator: del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J. et al.
Object Type: Article
System: The UNT Digital Library
Advanced Compton scattering light source R&D at LLNL (open access)

Advanced Compton scattering light source R&D at LLNL

None
Date: July 30, 2010
Creator: Albert, F.; Anderson, S. G.; Anderson, G.; Bayramian, A.; Betts, S. M.; Chu, T. S. et al.
Object Type: Article
System: The UNT Digital Library
Improvised Nuclear Device Response Training Materials (open access)

Improvised Nuclear Device Response Training Materials

None
Date: July 30, 2010
Creator: Olsen, E J & Buddemeier, B R
Object Type: Report
System: The UNT Digital Library
Determination of the spin-flip time in ferromagnetic SrRuO3 from time-resolved Kerr measurements (open access)

Determination of the spin-flip time in ferromagnetic SrRuO3 from time-resolved Kerr measurements

We report time-resolved Kerr effect measurements of magnetization dynamics in ferromagnetic SrRuO{sub 3}. We observe that the demagnetization time slows substantially at temperatures within 15K of the Curie temperature, which is {approx} 150K. We analyze the data with a phenomenological model that relates the demagnetization time to the spin flip time. In agreement with our observations the model yields a demagnetization time that is inversely proportional to T-T{sub c}. We also make a direct comparison of the spin flip rate and the Gilbert damping coefficient showing that their ratio very close to k{sub B}T{sub c}, indicating a common origin for these phenomena.
Date: July 30, 2010
Creator: Kantner, C. L. S.; Langner, M. C.; Siemons, W.; Blok, J. L.; Koster, G.; Rijnders, A.J. H. M. et al.
Object Type: Article
System: The UNT Digital Library
FEEDSTOCK-FLEXIBLE REFORMER SYSTEM (FFRS) FOR SOLID OXIDE FUEL CELL (SOFC)- QUALITY SYNGAS (open access)

FEEDSTOCK-FLEXIBLE REFORMER SYSTEM (FFRS) FOR SOLID OXIDE FUEL CELL (SOFC)- QUALITY SYNGAS

The U.S. Department of Energy National Energy Technology Laboratory funded this research collaboration effort between NextEnergy and the University of Michigan, who successfully designed, built, and tested a reformer system, which produced highquality syngas for use in SOFC and other applications, and a novel reactor system, which allowed for facile illumination of photocatalysts. Carbon and raw biomass gasification, sulfur tolerance of non-Platinum Group Metals (PGM) based (Ni/CeZrO2) reforming catalysts, photocatalysis reactions based on TiO2, and mild pyrolysis of biomass in ionic liquids (ILs) were investigated at low and medium temperatures (primarily 450 to 850 C) in an attempt to retain some structural value of the starting biomass. Despite a wide range of processes and feedstock composition, a literature survey showed that, gasifier products had narrow variation in composition, a restriction used to develop operating schemes for syngas cleanup. Three distinct reaction conditions were investigated: equilibrium, autothermal reforming of hydrocarbons, and the addition of O2 and steam to match the final (C/H/O) composition. Initial results showed rapid and significant deactivation of Ni/CeZrO2 catalysts upon introduction of thiophene, but both stable and unstable performance in the presence of sulfur were obtained. The key linkage appeared to be the hydrodesulfurization activity of the …
Date: July 30, 2010
Creator: Jezierski, Kelly; Tadd, Andrew; Schwank, Johannes; Kibler, Roland; McLean, David; Samineni, Mahesh et al.
Object Type: Report
System: The UNT Digital Library
2010 Thin Film & Small Scale Mechanical Behavior Gordon Research Conference (open access)

2010 Thin Film & Small Scale Mechanical Behavior Gordon Research Conference

Over the past decades, it has been well established that the mechanical behavior of materials changes when they are confined geometrically at least in one dimension to small scale. It is the aim of the 2010 Gordon Conference on 'Thin Film and Small Scale Mechanical Behavior' to discuss cutting-edge research on elastic, plastic and time-dependent deformation as well as degradation mechanisms like fracture, fatigue and wear at small scales. As in the past, the conference will benefit from contributions from fundamental studies of physical mechanisms linked to material science and engineering reaching towards application in modern applications ranging from optical and microelectronic devices and nano- or micro-electrical mechanical systems to devices for energy production and storage. The conference will feature entirely new testing methodologies and in situ measurements as well as recent progress in atomistic and micromechanical modeling. Particularly, emerging topics in the area of energy conversion and storage, such as material for batteries will be highlighted. The study of small-scale mechanical phenomena in systems related to energy production, conversion or storage offer an enticing opportunity to materials scientists, who can provide new insight and investigate these phenomena with methods that have not previously been exploited.
Date: July 30, 2010
Creator: Balk, Dr. Thomas
Object Type: Article
System: The UNT Digital Library