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Deposit Summary (open access)

Deposit Summary

Deposit summary of $1,000.00 made on October 17, 2002.
Date: October 17, 2002
Creator: unknown
System: The UNT Digital Library
Inorganic, Radioisotopic, and Organic Analysis of 241-AP-101 Tank Waste (open access)

Inorganic, Radioisotopic, and Organic Analysis of 241-AP-101 Tank Waste

Battelle received five samples from Hanford waste tank 241-AP-101, taken at five different depths within the tank. No visible solids or organic layer were observed in the individual samples. Individual sample densities were measured, then the five samples were mixed together to provide a single composite. The composite was homogenized and representative sub-samples taken for inorganic, radioisotopic, and organic analysis. All analyses were performed on triplicate sub-samples of the composite material. The sample composite did not contain visible solids or an organic layer. A subsample held at 10?C for seven days formed no visible solids.
Date: October 17, 2000
Creator: Fiskum, Sandra K.; Bredt, Paul R.; Campbell, James A.; Farmer, Orville T.; Greenwood, Lawrence R.; Hoppe, Eric W. et al.
System: The UNT Digital Library
Contribution to: SciDAC Progess Report - Collaborative Design and Development of the Community Climate System Model for Terascale Computing (open access)

Contribution to: SciDAC Progess Report - Collaborative Design and Development of the Community Climate System Model for Terascale Computing

Since pre-industrial times, the concentrations of various aerosol types (e.g., sulfate, black carbon, and mineral dust) and several key greenhouse gases such as methane (CH{sub 4}), nitrous oxide (N{sub 2}O), and ozone (O{sub 3}), have been changing because of anthropogenic activities. Collectively, the magnitude of the climate forcing from these species is larger than that of carbon dioxide (CO{sub 2}) although some are positive and some are negative (see Fig. 27). The behavior and effect of these non-CO{sub 2} species is more complicated than for CO{sub 2} because they are affected by atmospheric chemistry and aerosol microphysics, so their distributions are more heterogeneous. There are also feedbacks between climate, chemistry, and aerosols that further increase the importance of chemistry and aerosols, e.g. a change in any one of stratospheric ozone, stratospheric temperature, or stratospheric dynamics will feedback on the other two. For aerosols, in addition to the direct effect of scattering and absorbing light, they act indirectly by serving as cloud condensation nuclei (CCN), leading to clouds with more (but smaller) droplets that reflect more sunlight and last longer, thus cooling the atmosphere. Aerosols and atmospheric chemistry can also have an impact through interaction with the biosphere, e.g., fertilization of …
Date: October 17, 2003
Creator: Cameron-Smith, P; Caldeira, K; Taylor, J & Lamarque, J F
System: The UNT Digital Library
Interim Letter Report - Verification Survey of 19 Grids in the Lester Flat Area, David Witherspoon Inc. 1630 Site Knoxville, Tennessee (open access)

Interim Letter Report - Verification Survey of 19 Grids in the Lester Flat Area, David Witherspoon Inc. 1630 Site Knoxville, Tennessee

Perform verification surveys of 19 available grids located in the Lester Flat Area at the Davod Witherspoon Site. The survey grids included E11, E12, E13, F11, F12, F13, F14, F15, G15, G16, G17, H16, H17, H18, X16, X17, X18, K16, and J16.
Date: October 17, 2008
Creator: Weaver, P. C.
System: The UNT Digital Library
Physical Sciences Facility Air Emission Control Equivalency Evaluation (open access)

Physical Sciences Facility Air Emission Control Equivalency Evaluation

This document presents the adequacy evaluation for the application of technology standards during design, fabrication, installation and testing of radioactive air exhaust systems at the Physical Sciences Facility (PSF), located on the Horn Rapids Triangle north of the Pacific Northwest National Laboratory (PNNL) complex. The analysis specifically covers the exhaust portion of the heating, ventilation and air conditioning (HVAC) systems associated with emission units EP-3410-01-S, EP-3420-01-S and EP 3430-01-S.
Date: October 17, 2008
Creator: Brown, David M. & Belew, Shan T.
System: The UNT Digital Library
Advanced Waveform Simulation for Seismic Monitoring Events (open access)

Advanced Waveform Simulation for Seismic Monitoring Events

This quarter, we have focused on several tasks: (1) Building a high-quality catalog of earthquake source parameters for the Middle East and East Asia. In East Asia, we computed source parameters using the CAP method for a set of events studied by Herrman et al., (MRR, 2006) using a complete waveform technique. Results indicated excellent agreement with the moment magnitudes in the range 3.5 -5.5. Below magnitude 3.5 the scatter increases. For events with more than 2-3 observations at different azimuths, we found good agreement of focal mechanisms. Depths were generally consistent, although differences of up to 10 km were found. These results suggest that CAP modeling provides estimates of source parameters at least as reliable as complete waveform modeling techniques. However, East Asia and the Yellow Sea Korean Paraplatform (YSKP) region studied are relatively laterally homogeneous and may not benefit from the CAP method’s flexibility to shift waveform segments to account for path-dependent model errors. A more challenging region to study is the Middle East where strong variations in sedimentary basin, crustal thickness and crustal and mantle seismic velocities greatly impact regional wave propagation. We applied the CAP method to a set of events in and around Iran and …
Date: October 17, 2008
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
System: The UNT Digital Library
Time-dependent Dalitz-Plot Analysis of the Charmless Decay B^0 -> K^0S Pi Pi- at BABAR (open access)

Time-dependent Dalitz-Plot Analysis of the Charmless Decay B^0 -> K^0S Pi Pi- at BABAR

A time-dependent amplitude analysis of B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} decays is performed in order to extract the CP violation parameters of f{sub 0}(980)K{sub S}{sup 0} and {rho}{sup 0}(770)K{sub S}{sup 0} and direct CP asymmetries of K*{sup +}(892){pi}{sup -}. The results are obtained from the final BABAR data sample of (465 {+-} 5)10{sup 6} B{bar B} decays, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The time dependent CP asymmetry for f{sub 0}(980)K{sub S}{sup 0} and {rho}{sup 0}(770)K{sub S}{sup 0} are measured to be S(f{sub 0}(980)K{sub S}{sup 0}) = -0.97 {+-} 0.09 {+-} 0.01 {+-} 0.01, and S({rho}{sup 0}(770)K{sub S}{sup 0}) = 0.67 {+-} 0.20 {+-} 0.06 {+-} 0.04, respectively. In decays to K*{sup +}(892){pi}{sup -} the direct CP asymmetry is found to be A{sub CP}(K*{sup {+-}}(892){pi}{sup {-+}}) = -0.18 {+-} 0.10 {+-} 0.04 {+-} 0.00. The relative phases between B{sup 0} {yields} K*{sup +}(892){pi}{sup -} and {bar B}{sup 0} {yields} K*{sup -}(892){pi}{sup +}, relevant for the extraction of the unitarity triangle angle {gamma}, is measured to be {Delta}{phi}(K*(892){pi}) = (34.9 {+-} 23.1 {+-} 7.5 {+-} 4.7){sup o}, where uncertainties are statistical, systematic and model-dependent, respectively. Fit fractions, direct CP asymmetries and …
Date: October 17, 2009
Creator: Ilic, J
System: The UNT Digital Library
Assessment of Next Generation Nuclear Plant Intermediate Heat Exchanger Design. (open access)

Assessment of Next Generation Nuclear Plant Intermediate Heat Exchanger Design.

The Next Generation Nuclear Plant (NGNP), which is an advanced high temperature gas reactor (HTGR) concept with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 900-1000 C. In the indirect cycle system, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, nitrogen/helium mixture, or a molten salt. The system concept for the vary high temperature reactor (VHTR) can be a reactor based on the prismatic block of the GT-MHR developed by a consortium led by General Atomics in the U.S. or based on the PBMR design developed by ESKOM of South Africa and British Nuclear Fuels of U.K. This report has made an assessment on the issues pertaining to the intermediate heat exchanger (IHX) for the NGNP. A detailed thermal hydraulic analysis, using models developed at ANL, was performed to calculate heat transfer, temperature distribution, and pressure drop. Two IHX designs namely, shell and straight tube and compact heat exchangers were considered in an earlier assessment. Helical coil heat exchangers were analyzed in the …
Date: October 17, 2008
Creator: Majumdar, S.; Moisseytsev, A. & Natesan, K.
System: The UNT Digital Library
Investigation of the Quantrum Structure of Surfaces with Far UV Excitation Spectrosscopies (open access)

Investigation of the Quantrum Structure of Surfaces with Far UV Excitation Spectrosscopies

Clean surfaces and those with adsorbates have been investigated to obtain electronic and atomic structure data. The various modes of synchrotron radiation (SR) photoemission spectroscopy (PES) have been performed mostly beam line 7.0.1 at the Advanced Light Source (ALS) in Berkeley, CA and some at the Synchrotron Radiation Center (SRC) in Madison, WI. These were done on silicon, carbon, and group III nitrides.
Date: October 17, 2008
Creator: Lapeyre, Gerlad
System: The UNT Digital Library
Native American Technical Assistance and Training for Renewable Energy Resource Development and Electrical Generation Facilities Management (open access)

Native American Technical Assistance and Training for Renewable Energy Resource Development and Electrical Generation Facilities Management

The Council of Energy Resource Tribes (CERT) will facilitate technical expertise and training of Native Americans in renewable energy resource development for electrical generation facilities, and distributed generation options contributing to feasibility studies, strategic planning and visioning. CERT will also provide information to Tribes on energy efficiency and energy management techniques.This project will provide facilitation and coordination of expertise from government agencies and private industries to interact with Native Americans in ways that will result in renewable energy resource development, energy efficiency program development, and electrical generation facilities management by Tribal entities. The intent of this cooperative agreement is to help build capacity within the Tribes to manage these important resources.
Date: October 17, 2008
Creator: Lester, A. David
System: The UNT Digital Library
Final Report for "Design calculations for high-space-charge beam-to-RF conversion". (open access)

Final Report for "Design calculations for high-space-charge beam-to-RF conversion".

Accelerator facility upgrades, new accelerator applications, and future design efforts are leading to novel klystron and IOT device concepts, including multiple beam, high-order mode operation, and new geometry configurations of old concepts. At the same time, a new simulation capability, based upon finite-difference “cut-cell” boundaries, has emerged and is transforming the existing modeling and design capability with unparalleled realism, greater flexibility, and improved accuracy. This same new technology can also be brought to bear on a difficult-to-study aspect of the energy recovery linac (ERL), namely the accurate modeling of the exit beam, and design of the beam dump for optimum energy efficiency. We have developed new capability for design calculations and modeling of a broad class of devices which convert bunched beam kinetic energy to RF energy, including RF sources, as for example, klystrons, gyro-klystrons, IOT's, TWT’s, and other devices in which space-charge effects are important. Recent advances in geometry representation now permits very accurate representation of the curved metallic surfaces common to RF sources, resulting in unprecedented simulation accuracy. In the Phase I work, we evaluated and demonstrated the capabilities of the new geometry representation technology as applied to modeling and design of output cavity components of klystron, IOT's, …
Date: October 17, 2008
Creator: Smithe, David N
System: The UNT Digital Library
Final Report for "FSML – Fusion Simulation Markup Language". (open access)

Final Report for "FSML – Fusion Simulation Markup Language".

The developed software consists of two parts: FSML and VizSchema. FSML is based on an XML schema that represents the visualization entities needed for displaying fields and particles data in visualization tools. Each application is then represented by an XML instance mapping its data into the XML schema. Such XML file is used by the FSML reading library to bring in fields, particles and meshes from HDF5 files into memory. Based on this library, we developed AVS/Express and VisIt plugins. The second (more flexible) part of the software is called VizSchema. It consists of the schema expressed as a set of conventions and static data in the VizSchema code. The conventions describe the markup and organization of HDF5 data that would allow easy interpretation of data in the visualization terms. Based on theses conventions, a C++ HDF5-specific API for reading the visualization data was created. Finally, based on this library, we developed a new VisIt plugin (called Vs), which allows importing data from multiple applications using the markup. These applications include VORPAL, FACETS, UEDGE, NIMROD and MODAVE. The plugin will be included into the next releases of VisIt.
Date: October 17, 2008
Creator: Shasharina, Svetlana
System: The UNT Digital Library
Uncertainty in Integrated Assessment Scenarios (open access)

Uncertainty in Integrated Assessment Scenarios

The determination of climate policy is a decision under uncertainty. The uncertainty in future climate change impacts is large, as is the uncertainty in the costs of potential policies. Rational and economically efficient policy choices will therefore seek to balance the expected marginal costs with the expected marginal benefits. This approach requires that the risks of future climate change be assessed. The decision process need not be formal or quantitative for descriptions of the risks to be useful. Whatever the decision procedure, a useful starting point is to have as accurate a description of climate risks as possible. Given the goal of describing uncertainty in future climate change, we need to characterize the uncertainty in the main causes of uncertainty in climate impacts. One of the major drivers of uncertainty in future climate change is the uncertainty in future emissions, both of greenhouse gases and other radiatively important species such as sulfur dioxide. In turn, the drivers of uncertainty in emissions are uncertainties in the determinants of the rate of economic growth and in the technologies of production and how those technologies will change over time. This project uses historical experience and observations from a large number of countries to …
Date: October 17, 2005
Creator: Webster, Mort
System: The UNT Digital Library
Phase Stability under Irradiation of Precipitates and Solid Solutions in Model ALloys and in ODS Alloys Relevant for Gen IV (open access)

Phase Stability under Irradiation of Precipitates and Solid Solutions in Model ALloys and in ODS Alloys Relevant for Gen IV

The overall objective of this program is to investigate the irradiation-altered phase stability of oxide precipitates in ODS steels and of model alloy solid solutions of associated systems. This information can be used to determine whether the favorable mechanical propertiies of these steels are maintained under irradiation, thus addressing one of the main materials research issues for this class of steels as identified by the GenIV working groups. The research program will also create fundamental understanding of the irradiation precipitation/dissolution problem by studying a "model" system in which the variables can be controlled and their effects understood individually.
Date: October 17, 2007
Creator: Motta, Arthur T. & Birtcher, Robert C.
System: The UNT Digital Library
Laser-Plasma Interactions in High-Energy-Density Plasmas (open access)

Laser-Plasma Interactions in High-Energy-Density Plasmas

High temperature hohlraums (HTH) are designed to reach high radiation temperatures by coupling a maximum amount of laser energy into a small target in a short time. These 400-800 {micro}m diameter gold cylinders rapidly fill with hot plasma during irradiation with multiple beams in 1ns laser pulses. The high-Z plasmas are dense, (electron density, n{sub e}/n{sub c} {approx} 0.1-0.4), hot (electron temperature, T{sub e} {approx} 10keV) and are bathed in a high-temperature radiation field (radiation temperature, T{sub rad} {approx} 300eV). Here n{sub c}, the critical density, equals 9 x 10{sup 21}/cm{sup 3}. The laser beams heating this plasma are intense ({approx} 10{sup 15} - 10{sup 17} W/cm{sup 2}). The coupling of the laser to the plasma is a rich regime for Laser-Plasma Interaction (LPI) physics. The LPI mechanisms in this study include beam deflection and forward scattering. In order to understand the LPI mechanisms, the plasma parameters must be known. An L-band spectrometer is used to measure the and electron temperature. A ride-along experiment is to develop the x-radiation emitted by the thin back wall of the half-hohlraum into a thermal radiation source.
Date: October 17, 2006
Creator: Baldis, H
System: The UNT Digital Library
A Search for the Rare Leptonic B- to tau- anti-neutrino Recoiling against B+ to Decays to anti-D*0 l+ Lepton-neutrino (open access)

A Search for the Rare Leptonic B- to tau- anti-neutrino Recoiling against B+ to Decays to anti-D*0 l+ Lepton-neutrino

This thesis describes a search for the decay B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}} in 231.8 x 10{sup 6} {Upsilon}(4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B{sup +} {yields} {bar D}*{sup 0} {ell}{sup +}{nu}{sub {ell}}) is selected, and in the recoil a search for B{sup -} {yields} {tau}{sup -} {bar {nu}}{sub {tau}} signal is performed in the following {tau} decay modes: {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {tau}{sup -} {yields} {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}, {tau}{sup -} {yields} {pi}{sup -}{pi}{sup 0}{nu}{sub {tau}}, and {tau}{sup -} {yields} {pi}{sup -}{pi}{sup +}{pi}{sup -}{nu}{sub {tau}}. They find no evidence of signal, and they set a preliminary upper limit on the branching fraction of {beta}(B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}}) < 2.8 x 10{sup -4} at the 90% confidence level (CL). This result is then combined with a statistically independent BABAR search for B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}} to give a combined preliminary limit of {Beta}(B{sup -} {yields} {tau}{sup -}{bar {nu}}{sub {tau}}) < 2.6 x 10{sup -4} at 90% CL.
Date: October 17, 2006
Creator: Datta, Mousumi
System: The UNT Digital Library
Public Release of a One Dimensional Version of the Photon Clean Method (PCM1D) (open access)

Public Release of a One Dimensional Version of the Photon Clean Method (PCM1D)

We announce the public release of a one dimensional version of the Photon Clean Method (PCM1D). This code is in the general class of 'inverse Monte Carlo' methods and is specifically designed to interoperate with the public analysis tools available from the Chandra Science Center and the HEASARC. The tool produces models of event based data on a photon by photon basis. The instrument models are based on the standard ARF and RMF fits files. The resulting models have a high number of degrees of freedom of order the number of photons detected providing an alternative analysis compared to the usual method of fitting models with only a few parameters. The original work on this method is described in ADASS 1996 (Jernigan and Vezie).
Date: October 17, 2006
Creator: Carpenter, M H & Jernigan, J G
System: The UNT Digital Library
Evaluation of Oil-Industry Stimulation Practices for Engineered Geothermal Systems (open access)

Evaluation of Oil-Industry Stimulation Practices for Engineered Geothermal Systems

Geothermal energy extraction is typically achieved by use of long open-hole intervals in an attempt to connect the well with the greatest possible rock mass. This presents a problem for the development of Enhanced (Engineered) Geothermal Systems (EGS), owing to the challenge of obtaining uniform stimulation throughout the open-hole interval. Fluids are often injected in only a fraction of that interval, reducing heat transfer efficiency and increasing energy cost. Pinnacle Technologies, Inc. and GeothermEx, Inc. evaluated a variety of techniques and methods that are commonly used for hydraulic fracturing of oil and gas wells to increase and evaluate stimulation effectiveness in EGS wells. Headed by Leen Weijers, formerly Manager of Technical Development at Pinnacle Technologies, Inc., the project ran from August 1, 2004 to July 31, 2006 in two one-year periods to address the following tasks and milestones: 1) Analyze stimulation results from the closest oil-field equivalents for EGS applications in the United States (e.g., the Barnett Shale in North Texas) (section 3 on page 8). Pinnacle Technologies, Inc. has collected fracture growth data from thousands of stimulations (section 3.1 on page 12). This data was further evaluated in the context of: a) Identifying techniques best suited to developing a …
Date: October 17, 2007
Creator: Dyke, Peter Van; Weijers, Leen; Robertson-Tait, Ann; Warpinski, Norm; Mayerhofer, Mike; Minner, Bill et al.
System: The UNT Digital Library
Louisiana Industrial Assessment Center--Final Technical Report (open access)

Louisiana Industrial Assessment Center--Final Technical Report

This is the Final Report for the Louisiana Industrial Assessment Center for the period of 9/1/2002 through 11/30/2006, although we were still gathering data through 02/16/2007. During this period, our Industrial Assessment Center completed 109 energy assessments for manufacturing firms in our area, offered 3 Save Energy Workshops, taught 26 students (9 graduate and 17 undergraduate) energy management savings techniques and offered an Energy Management Graduate class three times. These 109 energy assessments made a total of 738 energy savings recommendations, 33 waste reduction recommendations, and 108 productivity improvement recommendations. These combined recommendations would save client companies more than $87,741,221.16, annually at the then current energy costs. If all of these recommendations were implemented separately, the implementation cost would have been $34,113,482.10 or a Simple Payback Period, SPP=4.7 months. Between 9 months and 12 months after the assessment, we surveyed the manufacturing firms to find out what they implemented. They had implemented approximately 50 percent of our recommendations at an annual saving of $25,867,613.18. The three Save Energy Workshops had an average attendance of twelve individuals. The three graduate Energy Management courses had an average attendance of eleven students.
Date: October 17, 2007
Creator: Kozman, Theodore A.
System: The UNT Digital Library
Heat Transfer Analysis for Fixed Cst and Rf Columns (open access)

Heat Transfer Analysis for Fixed Cst and Rf Columns

In support of a small column ion exchange (SCIX) process for the Savannah River Site waste processing program, transient and steady state two-dimensional heat transfer models have been constructed for columns loaded with cesium-saturated crystalline silicotitanate (CST) or spherical Resorcinol-Formaldehyde (RF) beads and 6 molar sodium tank waste supernate. Radiolytic decay of sorbed cesium results in heat generation within the columns. The models consider conductive heat transfer only with no convective cooling and no process flow within the columns (assumed column geometry: 27.375 in ID with a 6.625 in OD center-line cooling pipe). Heat transfer at the column walls was assumed to occur by natural convection cooling with 35 C air. A number of modeling calculations were performed using this computational heat transfer approach. Minimal additional calculations were also conducted to predict temperature increases expected for salt solution processed through columns of various heights at the slowest expected operational flow rate of 5 gpm. Results for the bounding model with no process flow and no active cooling indicate that the time required to reach the boiling point of {approx}130 C for a CST-salt solution mixture containing 257 Ci/liter of Cs-137 heat source (maximum expected loading for SCIX applications) at 35 …
Date: October 17, 2007
Creator: Lee, S.
System: The UNT Digital Library
Organic Geochemistry of Continental Margin and Deep Ocean Sediments (open access)

Organic Geochemistry of Continental Margin and Deep Ocean Sediments

None
Date: October 17, 2006
Creator: Whelan, Jean K.
System: The UNT Digital Library
Center for Catalysis at Iowa State University (open access)

Center for Catalysis at Iowa State University

The overall objective of this proposal is to enable Iowa State University to establish a Center that enjoys world-class stature and eventually enhances the economy through the transfer of innovation from the laboratory to the marketplace. The funds have been used to support experimental proposals from interdisciplinary research teams in areas related to catalysis and green chemistry. Specific focus areas included: • Catalytic conversion of renewable natural resources to industrial materials • Development of new catalysts for the oxidation or reduction of commodity chemicals • Use of enzymes and microorganisms in biocatalysis • Development of new, environmentally friendly reactions of industrial importance These focus areas intersect with barriers from the MYTP draft document. Specifically, section 2.4.3.1 Processing and Conversion has a list of bulleted items under Improved Chemical Conversions that includes new hydrogenation catalysts, milder oxidation catalysts, new catalysts for dehydration and selective bond cleavage catalysts. Specifically, the four sections are: 1. Catalyst development (7.4.12.A) 2. Conversion of glycerol (7.4.12.B) 3. Conversion of biodiesel (7.4.12.C) 4. Glucose from starch (7.4.12.D) All funded projects are part of a soybean or corn biorefinery. Two funded projects that have made significant progress toward goals of the MYTP draft document are: Catalysts to convert …
Date: October 17, 2006
Creator: Kraus, George A.
System: The UNT Digital Library
CRADA Final Report for CRADA No. ORNL99-0544, Interfacial Properties of Electron Beam Cured Composites (open access)

CRADA Final Report for CRADA No. ORNL99-0544, Interfacial Properties of Electron Beam Cured Composites

Electron beam (EB) curing is a technology that promises, in certain applications, to deliver lower cost and higher performance polymer matrix composite (PMC) structures compared to conventional thermal curing processes. PMCs enhance performance by making products lighter, stronger, more durable, and less energy demanding. They are essential in weight- and performance-dominated applications. Affordable PMCs can enhance US economic prosperity and national security. US industry expects rapid implementation of electron beam cured composites in aircraft and aerospace applications as satisfactory properties are demonstrated, and implementation in lower performance applications will likely follow thereafter. In fact, at this time and partly because of discoveries made in this project, field demonstrations are underway that may result in the first fielded applications of electron beam cured composites. Serious obstacles preventing the widespread use of electron beam cured PMCs in many applications are their relatively poor interfacial properties and resin toughness. The composite shear strength and resin toughness of electron beam cured carbon fiber reinforced epoxy composites were about 25% and 50% lower, respectively, than those of thermally cured composites of similar formulations. The essential purpose of this project was to improve the mechanical properties of electron beam cured, carbon fiber reinforced epoxy composites, with …
Date: October 17, 2005
Creator: Janke, C.J.
System: The UNT Digital Library
The B -> pi Form Factor from Light-cone Sum Rules in Soft-collinear Effective Theory (open access)

The B -> pi Form Factor from Light-cone Sum Rules in Soft-collinear Effective Theory

Recently, we have derived light-cone sum rules for exclusive B-meson decays into light energetic hadrons from correlation functions within soft-collinear effective theory [1]. In these sum rules the short-distance scale refers to ''hard-collinear'' interactions with virtualities of order {Lambda}{sub QCD}m{sub b}. Hard scales (related to virtualities of order m{sub b}{sup 2}) are integrated out and enter via external coefficient functions in the sum rule. Soft dynamics is encoded in light-cone distribution amplitudes for the B-meson, which describe both the factorizable and non-factorizable contributions to exclusive B-meson decay amplitudes. Factorization of the correlation function has been verified to one-loop accuracy. Thus, a systematic separation of hard, hard-collinear, and soft dynamics in the heavy-quark limit is possible.
Date: October 17, 2005
Creator: Hurth, Tobias; /SLAC, /CERN; De Fazio, Fulvia; /INFN, Bari; Feldmann, Thorsten & U., /Siegen
System: The UNT Digital Library