Serial/Series Title
Hanford Laboratories Operation Monthly Activities Report
37
Evaluation of Roof Bolting Requirements Based on In-Mine Bolter Drilling Progress Report
16
BEETIT Program
12
Irradiation Processing Department Monthly Report
11
ANL Reactor Development Program Progress Report
10
Low-Cost Solar Array Project
6
A Development of On-Line Temperature Measurement Instrumentation for Gasification Process Control Progress Report
4
Fiscal Year 2003
4
Fiscal Year 2004
3
Winter Fuels Report
3
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6,421 Matching Results
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Electrical and optical properties of carbon-doped GaN grown by MBE on MOCVD GaN templates using a CCl4 dopant source
Carbon-doped GaN was grown by plasma-assisted molecular-beam epitaxy using carbon tetrachloride vapor as the dopant source. For moderate doping mainly acceptors were formed, yielding semi-insulating GaN. However at higher concentrations p-type conductivity was not observed, and heavily doped films (>5 x 10{sup 20} cm{sup -3}) were actually n-type rather than semi-insulating. Photoluminescence measurements showed two broad luminescence bands centered at 2.2 and 2.9 eV. The intensity of both bands increased with carbon content, but the 2.2 eV band dominated in n-type samples. Intense, narrow ({approx}6 meV) donor-bound exciton peaks were observed in the semi-insulating samples.
Date:
April 15, 2002
Creator:
Armitage, Rob; Yang, Qing; Feick, Henning; Park, Yeonjoon & Weber, Eicke R.
Object Type:
Article
System:
The UNT Digital Library
An investigation of bridge width measurement and processing capabilities (1985)
An investigation of Mound`s ability to measure and process bridges was conducted in 1985. Prior to improvements in the measuring system and technique, bridge width was found to have a sigma of 0.00019 in. After improvements were made, a sigma of 0.000047 was realized. Bridge length was found to be more erratic than width, although most of the inaccuracy was caused by measurement uncertainty. Length and width were found to have little or no correlation.
Date:
May 15, 1989
Creator:
Armstrong, K.P.
Object Type:
Report
System:
The UNT Digital Library
Enzyme catalysts for a biotechnology-based chemical industry. Quarterly progress report, September 29--December 28, 1997
The goal of this research is to engineer enzymes to be efficient and economically attractive catalysts for the chemical industry. The author is attempting to demonstrate generally-applicable approaches to enzyme improvement as well as develop specific catalysts for potential industrial application. In this report attention is focused on random mutagenesis of pNB esterase -- improved activity and stability. The most thermostable esterases obtained by sequential random mutagenesis (6H7) and random mutagenesis plus recombination (6sF9) each contain 9 amino acid mutations and a number of silent mutations, relative to the wild-type sequence. Eight of the mutations are present in both genes, for a total of ten potentially adaptive mutations. Because several of these mutations occurred in the same generation, it is difficult to identify the mutations responsible for the increases in activity and stability. In order to aid in this identification, the thermostable genes were recombined with the wild-type gene, in hopes of removing neutral mutations. The gene from the first-generation variant, with five amino acid substitutions was also recombined with wild-type.
Date:
January 15, 1998
Creator:
Arnold, F.H.
Object Type:
Report
System:
The UNT Digital Library
The FEL development at the Advanced Photon Source.
Construction of a single-pass free-electron laser (FEL) based on the self-amplified spontaneous emission (SASE) mode of operation is nearing completion at the Advanced Photon Source (APS) with initial experiments imminent. The APS SASE FEL is a proof-of-principle fourth-generation light source. As of January 1999 the undulator hall, end-station building, necessary transfer lines, electron and optical diagnostics, injectors, and initial undulatory have been constructed and, with the exception of the undulatory, installed. All preliminary code development and simulations have also been completed. The undulator hall is now ready to accept first beam for characterization of the output radiation. It is the project goal to push towards fill FEL saturation, initially in the visible, but ultimately to W and VUV, wavelengths.
Date:
March 15, 1999
Creator:
Arnold, N. D.; Benson, C.; Berg, S.; Berg, W.; Biedron, S. G.; Chae, Y. C. et al.
Object Type:
Article
System:
The UNT Digital Library
Gas Chemistry in Geothermal Systems
Five new gas geothermometers are introduced. They are useful for predicting subsurface temperatures in water dominated geothermal systems. The geothermometers use data on CO{sub 2}, H{sub 2}S and H{sub 2} concentrations in fumarole steam as well as CO{sub 2}/H{sub 2} and H{sub 2}S/H{sub 2} ratios. It is demonstrated that the gas composition of fumarole steam may be used with or withour drillhole data to evaluate steam condensation in the upflow zones of geothermal systems. Uncertainty exists, however, in distinguishing between the effects of steam condensation and phase separation at elevated pressures. The gas content in steam from discharging wells and the solute content of the water phase can be used to evaluate which boiling processes lead to "excess steam" in the discharge and at which temperature this "excess steam" is added to the fluid moving through the aquifer and into the well. Examples, using field data, are given to demonstrate all the mentioned applications of geothermal chemistry.
Date:
December 15, 1983
Creator:
Arnorsson, Stefan & Gunnlaugsson, Einar
Object Type:
Article
System:
The UNT Digital Library
Development and function of membrane systems in plant tissue. Annual progress report, 15 July 1974--14 July 1975. [Ion transport in corn roots]
None
Date:
July 15, 1975
Creator:
Arntzen, C.J.
Object Type:
Report
System:
The UNT Digital Library
Evaluating greenhouse gas emissions from hydropower complexes on large rivers in Eastern Washington
Water bodies, such as freshwater lakes, are known to be net emitters of carbon dioxide (CO2), and methane (CH4). In recent years, significant greenhouse gas (GHG) emissions from tropical, boreal, and mid-latitude reservoirs have been reported. At a time when hydropower is increasing worldwide, better understanding of seasonal and regional variation in GHG emissions is needed in order to develop a predictive understanding of such fluxes within man-made impoundments. We examined power-producing dam complexes within xeric temperate locations in the northwestern United States. Sampling environments on the Snake (Lower Monumental Dam Complex) and Columbia Rivers (Priest Rapids Dam Complex) included tributary, mainstem, embayment, forebay, and tailrace areas during winter and summer 2012. At each sampling location, GHG measurement pathways included surface gas flux, degassing as water passed through dams during power generation, ebullition within littoral embayments, and direct sampling of hyporheic pore-water. Measurements were also carried out in a free-flowing reach of the Columbia River to estimate unaltered conditions. Surface flux resulted in very low emissions, with reservoirs acting as a sink for CO2 (up to –262 mg m-2 d-1, which is within the range previously reported for similarly located reservoirs). Surface flux of methane remained below 1 mg CH4 …
Date:
March 15, 2013
Creator:
Arntzen, Evan V.; Miller, Benjamin L.; O'Toole, Amanda C.; Niehus, Sara E. & Richmond, Marshall C.
Object Type:
Report
System:
The UNT Digital Library
Relativistic shocks in electron-positron plasmas, and polar cap accretion onto neutron stars: Two non-linear problems in astrophysical plasma physics
I outline particle simulations and theory of relativistic shock waves in an e/sup +-/ plasma. Magnetic reflection of particles is an essential role in the shock structure. Instability of the reflected particles in the shock front produces intense extraordinary mode radiation. Such shocks are candidates for the particle accelerator in plerions and in extragalactic jets only if the upstream Poynting flux composes no more than 10% of the total. I summarize analytical and numerical studies of radiation dominated accretion onto the magnetic poles of neutron stars. The upper limit to the photon luminosity depends upon magnetic confinement, not upon the dragging of photons into the star. Numerical solutions show the plasma forms large scale ''photon bubbles.'' I suggest the percolative loss of radiation controls the pressure and therefore the limits of magnetic confinement. Loss of magnetic confinement through resistive interchange instability is suggested as a means of generating TeV to PeV voltage drops along the magnetic field. 34 refs., 6 figs., 1 tab.
Date:
August 15, 1988
Creator:
Arons, J.
Object Type:
Article
System:
The UNT Digital Library
FUEL BURNUP STUDIES FOR A 225 Mwe ADVANCED SODIUM GRAPHITE REACTOR
Reactivity and fuel burnup studies were performed for a 255 Mw(e) sodium- graphite reactor of the advanced calandria core type. This reactor is briefly described. Initial criticality calculations and flux distributions were obtained, using two-group theory for enrichments between 2.0 at.% U/sup 325/ and 4.0 at.% U235. A four-group burnup study was performed for enrichments between 2.5 at.% Uisup nd 3.25 at.% U/sup 235/. Core lifetime, changes in isotopic fuel composition, variations in radial power distribution, and fuel cross sec tions are presented. Reactivity during core lifetime was assumed to be controlled by the presence of a homogeneous poison which simulated the effects of control rcds. The results presentad are useful in determining initial enrichment selection in fuel programming and fuel cost studies. (auth)
Date:
June 15, 1960
Creator:
Aronson, A. L.
Object Type:
Report
System:
The UNT Digital Library
D phi detector
The D phi experiment is a recently approved effort at FERMILAB to study proton-antiproton collisions at 2 TeV. A powerful new detector has been designed for this experiment and is described. The D phi detector has been designed to optimize its discovery potential in the mass range where deviations from the Standard Model might be expected to manifest themselves. Rather than discussing the detector's response to particular hypothetical new states (Higgses, squarks, etc.), we focus here on more technical capabilities (leptons, jets, etc.). After a brief physics summary to motivate our technical choices, we consider the detector design subsystem by subsystem. 9 references.
Date:
March 15, 1984
Creator:
Aronson, S. H.
Object Type:
Article
System:
The UNT Digital Library
Gene expression profiles of Nitrosomonas europaea, an obligate chemolitotroph
Nitrosomonas europaea is an aerobic lithoautotrophic bacterium that uses ammonia (NH3) as its energy source. As a nitrifier, it is an important participant in the nitrogen cycle, which can also influence the carbon cycle. The focus of this work was to explore the genetic structure and mechanisms underlying the lithoautotrophic growth style of N. europaea. Whole genome gene expression. The gene expression profile of cells in exponential growth and during starvation was analyzed using microarrays. During growth, 98% of the genes increased in expression at least two fold compared to starvation conditions. In growing cells, approximately 30% of the genes were expressed eight fold higher, Approximately 10% were expressed more than 15 fold higher. Approximately 3% (91 genes) were expressed to more than 20 fold of their levels in starved cells. Carbon fixation gene expression. N. europaea fixes carbon via the Calvin-Benson-Bassham (CBB) cycle via a type I ribulose bisphosphate carboxylase/oxygenase (RubisCO). This study showed that transcription of cbb genes was up-regulated when the carbon source was limited, while amo, hao and other energy harvesting related genes were down-regulated. Iron related gene expression. Because N. europaea has a relatively high content of hemes, sufficient Fe must be available in the …
Date:
June 15, 2005
Creator:
Arp, Daniel J
Object Type:
Report
System:
The UNT Digital Library
Processing of High Level Waste: Spectroscopic Characterization of Redox Reactions in Supercritical Water - Final Report
Current efforts are focused on the oxidative dissolution of chromium compounds found in Hanford tank waste sludge. Samples of chromium oxides and hydroxides with varying degrees of hydration are being characterized using Raman, FTIR, and XPS spectroscopic techniques. Kinetics of oxidation reactions at subcritical and supercritical temperatures are being followed by Raman spectroscopy using a high temperature stainless steel cell with diamond windows. In these reactions both hydrogen peroxide and nitrate anions are used as the oxidizing species with Cr(III) compounds and organic compounds as reducing agents.
Date:
November 15, 2000
Creator:
Arrington, C. A., Jr.
Object Type:
Report
System:
The UNT Digital Library
Nucleon momentum distributions from a modified scaling analysis of inclusive electron-nucleus scattering.
Inclusive electron scattering from nuclei at low momentum transfer (corresponding to x {ge} 1) and moderate Q{sup 2} is dominated by quasifree scattering from nucleons. In the impulse approximation, the cross section can be directly connected to the nucleon momentum distribution via the scaling function F(y). The breakdown of the y-scaling assumptions in certain kinematic regions have prevented extraction of nucleon momentum distributions from such a scaling analysis. With a slight modification to the y-scaling assumptions, it is found that scaling functions can be extracted which are consistent with the expectations for the nucleon momentum distributions.
Date:
May 15, 2002
Creator:
Arrington, J.
Object Type:
Article
System:
The UNT Digital Library
Opportunities and Challenges for Alternative Fuels
Presentation given by Dan Arvizu at the Center for Strategic and International Studies (CSIS) Symposium on Future Fuels on June 15, 2006
Date:
June 15, 2006
Creator:
Arvizu, D.
Object Type:
Presentation
System:
The UNT Digital Library
Opportunities and Challenges for Alternative Fuels
Presented at the Center for Strategic and International Studies' Energy Program and Global Strategy Institute Series on Alternative Fuels on June 15, 2006 by Dr. Dan Arvizu.
Date:
June 15, 2006
Creator:
Arvizu, D.E.
Object Type:
Presentation
System:
The UNT Digital Library
Effect of shock wave risetime on material ejection from aluminum surfaces
The effect of shock wave risetime on material ejection in aluminum has been studied for loading stresses of 21 GPa. Uniform loading was accomplished with plate impact techniques by mounting specimens on a ramp wave generator. Projectile impact on one side of the wave generator produced a wave which dispersed with propagation distance. This wave was then made incident to an aluminum specimen, so that the specimen experienced non-shock loading. It was found that mass ejection from aluminum surfaces can be reduced by over two orders of magnitude relative to shock loading conditions by accelerating the surface with a wave risetime greater than about 35 ns. These results suggest an explanation for the apparent discrepancies which are sometimes observed in mass ejection measurements utilizing either plate impact or electron beam deposition to generate stress waves.
Date:
September 15, 1977
Creator:
Asay, J.R.
Object Type:
Report
System:
The UNT Digital Library
Fixing All Moduli for M-Theory on K3xK3
We analyze M-theory compactified on K3 x K3 with fluxes preserving half the supersymmetry and its F-theory limit, which is dual to an orientifold of the type IIB string on K3 x (T{sup 2}/Z{sub 2}). The geometry of attractive K3 surfaces plays a significant role in the analysis. We prove that the number of choices for the K3 surfaces is finite and we show how they can be completely classified. We list the possibilities in one case. We then study the instanton effects and see that they will generically fix all of the moduli. We also discuss situations where the instanton effects might not fix all the moduli.
Date:
June 15, 2005
Creator:
Aspinwall, Paul S.; /Stanford U., Phys. Dept. /SLAC /Duke U., CGTP; Kallosh, Renata & /Stanford U., Phys. Dept.
Object Type:
Article
System:
The UNT Digital Library
SNAP reactor programs. Progress report, May--July 1968
None
Date:
September 15, 1968
Creator:
Asquith, J. G.
Object Type:
Report
System:
The UNT Digital Library
U.S. Department of Energy Clean Cities Five-Year Strategic Plan
Clean Cities is a government-industry partnership sponsored by the U.S. Department of Energy's (DOE) Vehicle Technologies Program, which is part of the Office of Energy Efficiency and Renewable Energy. Working with its network of about 100 local coalitions and more than 6,500 stakeholders across the country, Clean Cities delivers on its mission to reduce petroleum consumption in on-road transportation. In its work to reduce petroleum use, Clean Cities focuses on a portfolio of technologies that includes electric drive, propane, natural gas, renewable natural gas/biomethane, ethanol/E85, biodiesel/B20 and higher-level blends, fuel economy, and idle reduction. Over the past 17 years, Clean Cities coalitions have displaced more than 2.4 billion gallons of petroleum; they are on track to displace 2.5 billion gallons of gasoline per year by 2020. This Clean Cities Strategic Plan lays out an aggressive five-year agenda to help DOE Clean Cities and its network of coalitions and stakeholders accelerate the deployment of alternative fuel and advanced technology vehicles, while also expanding the supporting infrastructure to reduce petroleum use. Today, Clean Cities has a far larger opportunity to make an impact than at any time in its history because of its unprecedented $300 million allocation for community-based deployment projects from …
Date:
February 15, 2011
Creator:
Associates, Cambridge Concord
Object Type:
Report
System:
The UNT Digital Library
Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure
We developed a mathematical method to analyze flow cytometry data to describe the kinetics of {gamma}H2AX and pATF2 phosphorylations ensuing various qualities of low dose radiation in normal human fibroblast cells. Previously reported flow cytometry kinetic results for these DSB repair phospho-proteins revealed that distributions of intensity were highly skewed, severely limiting the detection of differences in the very low dose range. Distributional analysis reveals significant differences between control and low dose samples when distributions are compared using the Kolmogorov-Smirnov test. Radiation quality differences are found in the distribution shapes and when a nonlinear model is used to relate dose and time to the decay of the mean ratio of phosphoprotein intensities of irradiated samples to controls. We analyzed cell cycle phase and radiation quality dependent characteristic repair times and residual phospho-protein levels with these methods. Characteristic repair times for {gamma}H2AX were higher following Fe nuclei as compared to X-rays in G1 cells (4.5 {+-} 0.46 h vs 3.26 {+-} 0.76 h, respectively), and in S/G2 cells (5.51 {+-} 2.94 h vs 2.87 {+-} 0.45 h, respectively). The RBE in G1 cells for Fe nuclei relative to X-rays for {gamma}H2AX was 2.05 {+-} 0.61 and 5.02 {+-} 3.47, at 2 …
Date:
December 15, 2010
Creator:
Association, Universities Space Research; Chappell, Lori J.; Whalen, Mary K.; Gurai, Sheena; Ponomarev, Artem; Cucinotta, Francis A. et al.
Object Type:
Article
System:
The UNT Digital Library
Structure and electrical activity of planar defects in EFG ribbons. First quarterly report, January 1--March 31, 1979
The structure and electrical activity of planar defects in EFG Silicon was investigated by optical, electron beam induced current (EBIC), and transmission electron microscopy (TEM). What appears to be twin boundaries by both optical microscopy + etching, and by EBIC are in reality systems of microtwins, some of which are only a few atomic lattice planes thick. The electrical activity of planar defects appears to be correlated with emission of dislocations especially at termination points. Impurity effects may also play a role. Twin boundaries per se appear not to be electricaly active.
Date:
April 15, 1979
Creator:
Ast, D.G.
Object Type:
Report
System:
The UNT Digital Library
Price allocation guidelines January 1980: Low-cost solar array project
The price allocation guidelines (PAG) are an integrated set of specific cost targets for several task areas within the Low-cost Solar Array (LSA) Project. PAG is a working tool of LSA Project management designed to provide consistent and meaningful guidelines for costs of polycrystalline silicon material, sheet, cells, encapsulants, and module manufacturing. It is expected that advanced photovoltaic concepts derived from industry and the research community can be developed so that it will be possible by the end of 1982 to demonstrate production processes, all process steps, and prototype equipment required to manufacture flat-plate photovoltaic modules. This demonstration would incorporate production rates and product quality consistent with a specific market price determined by the program. This stage of development has been referred to as Technical Readiness. A goal of $0.70 per peak watt (1980 dollars) has been established for the cost of electricity generated by photovoltaic modules. The processes for producing modules demonstrated to be technically ready must be amenable to scale-up so that this price goal can eventually be achieved in the marketplace. The guidelines described in this document allocate portions of that goal to each module component. Sheet materials derived from the following five technologies are considered: Czochralski, …
Date:
January 15, 1980
Creator:
Aster, R. W.
Object Type:
Report
System:
The UNT Digital Library
Air Conditioning with Magnetic Refrigeration
Advanced Research Projects Agency-Energy project sheet summarizing general information about the Building Energy Efficiency Through Innovative Thermodevices (BEETIT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses air conditioning with magnetic refrigeration as part of "An Efficient, Green Compact Cooling System Using Magnetic Refrigeration" project.
Date:
February 15, 2012
Creator:
Astronautics Corporation of America
Object Type:
Text
System:
The UNT Digital Library
Heavy Meson Production at a Low-Energy Photon Collider
A low-energy {gamma}{gamma} collider has been discussed in the context of a testbed for a {gamma}{gamma} interaction region at the Next Linear Collider(NLC). We consider the production of heavy mesons at such a testbed using Compton-backscattered photons and demonstrate that their production rivals or exceeds those by BELLE, BABAR or LEP where they are produced indirectly via virtual {gamma}{gamma} luminosities.
Date:
April 15, 2004
Creator:
Asztalos, S
Object Type:
Article
System:
The UNT Digital Library