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Office of Scientific & Technical Information Technical Reports
331
Texas Laws and Resolutions Archive
229
Congressional Research Service Reports
113
Texas Attorney General Opinions
48
Texas Patents
48
Government Accountability Office Reports
39
Technical Report Archive and Image Library
33
National Advisory Committee for Aeronautics Collection
25
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9
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866 Matching Results
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Manipulating Molecules: The National Nanotechnology Initiative
None
Date:
May 23, 2003
Creator:
Davey, Michael E.
Object Type:
Report
System:
The UNT Digital Library
Turboprop-engine design considerations 1: effect of mode of engine operation on performance of turboprop engine with current compressor pressure ratio
Report presenting a cycle analysis of a turboprop engine for various modes of operation over a range of flight conditions in order to determine whether one mode of operation has any marked advantages. The methods of operation explored included constant compressor equivalent design speed, constant design engine rotative speed, adjustable turbine stators, and variable exhaust-nozzle area.
Date:
May 23, 1955
Creator:
Davison, Elmer H.
Object Type:
Report
System:
The UNT Digital Library
Turboprop-engine design considerations 2: design requirements and performance of turboprop engines with a single-spool high-pressure-ratio compressor
Report of an investigation of the effect of mode of engine operation, engine configuration, and airplane flight condition on the performance and design requirements of a turboprop engine with a high-pressure-ratio single-spool compressor. Both single-spool engines and gas-generating engines are considered. The free-turbine engine was found to be less versatile than the single-spool engine because the range of turbine-inlet temperature over which it can operate is restricted.
Date:
May 23, 1955
Creator:
Davison, Elmer H. & Stalla, Margaret C.
Object Type:
Report
System:
The UNT Digital Library
Chest for Piston-Valves.
Patent for a valve chest "fitted for the reception and operation of a piston valve, easily applying to a piston cylinder of a locomotive in place of a removed slide-valve chest without loss of the cylinder, adapting to use superheated steam and high pressure." (lines 11-19).
Date:
May 23, 1916
Creator:
Dawson, Lance L. & Roach, John L.
Object Type:
Patent
System:
The Portal to Texas History
Zero-flux planes, flux reversals and diffusion paths in ternary and quaternary diffusion
During isothermal multicomponent diffusion, interdiffusion fluxes of individual components can go to zero at zero-flux planes (ZFP) and exhibit flux reversals from one side to the other of such planes. Interdiffusion fluxes as well as the locations and compositions of ZFPs for components are determined directly from the concentration profiles of diffusion couples without the need for prior knowledge of interdiffusion coefficients. The development and identification of ZFPs is reviewed with the aid of single phase and two-phase diffusion couples investigated in the Cu-Ni-Zn system at 775/sup 0/C. ZFP locations in the diffusion zone nearly correspond to sections where the activity of a component is the same as its activity in either of the terminal alloys of a couple. Path slopes at ZFPs are uniquely dictated by the atomic mobility and thermodynamic data for the components. Discontinuous flux reversals for the components can also occur at interfaces in multiphase couples. Identification of ZFPs is also presented for diffusion in the Cu-Ni-Zn-Mn quaternary system. Analytical representation of diffusion paths for both ternary and quaternary diffusion couples is presented with the aid of characteristic path parameters.
Date:
May 23, 1986
Creator:
Dayananda, M.A.
Object Type:
Report
System:
The UNT Digital Library
Maneuverability investigation of the F6C-3 airplane with special flight instruments
"This investigation was made for the purpose of obtaining information on the maneuverability of the F6C-3 airplane. It is the first of a series of similar investigations to be conducted on a number of military airplanes for the purpose of comparing the abilities of these airplanes to maneuver, and also to establish a fund of quantitative data which may be used in formulating standards of comparison for rating the maneuverability of any airplane. A large part of this initial investigation was necessarily devoted to the development and trial of methods suitable for use in subsequent investigations of this nature" (p. 117).
Date:
May 23, 1930
Creator:
Dearborn, C. H. & Kirschbaum, H. W.
Object Type:
Report
System:
The UNT Digital Library
Hybrid Paper/Electronic Archival Collecting, Processing, and Reference: A View from SLAC
Real-time archiving of mixed paper and digital collections presents challenges not encountered in the primarily paper environment. A few recent examples from the archives of the Stanford Linear Accelerator Center highlight obstacles encountered, and attempted and contemplated solutions.
Date:
May 23, 2008
Creator:
Deken, Jean M.
Object Type:
Article
System:
The UNT Digital Library
Generic Degraded Congiguration Probability Analysis for DOE Codisposal Waste Package
In accordance with the technical work plan, ''Technical Work Plan For: Department of Energy Spent Nuclear Fuel Work Packages'' (CRWMS M&O 2000c), this Analysis/Model Report (AMR) is developed for the purpose of screening out degraded configurations for U.S. Department of Energy (DOE) spent nuclear fuel (SNF) types. It performs the degraded configuration parameter and probability evaluations of the overall methodology specified in the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2000, Section 3) to qualifying configurations. Degradation analyses are performed to assess realizable parameter ranges and physical regimes for configurations. Probability calculations are then performed for configurations characterized by k{sub eff} in excess of the Critical Limit (CL). The scope of this document is to develop a generic set of screening criteria or models to screen out degraded configurations having potential for exceeding a criticality limit. The developed screening criteria include arguments based on physical/chemical processes and probability calculations and apply to DOE SNF types when codisposed with the high-level waste (HLW) glass inside a waste package. The degradation takes place inside the waste package and is long after repository licensing has expired. The emphasis of this AMR is on degraded configuration screening and the probability analysis is one of …
Date:
May 23, 2001
Creator:
Deng, S.F.A.; Saglam, M. & Gratton, L.J.
Object Type:
Report
System:
The UNT Digital Library
Hanford Tank 241-C-106: Residual Waste Contaminant Release Model and Supporting Data
This report was revised in May 2007 to correct values in Section 3.4.1.7, second paragraph, last sentence; 90Sr values in Tables 3.22 and 3.32; and 99Tc values Table 4.3 and in Chapter 5. In addition, the tables in Appendix F were updated to reflect corrections to the 90Sr values. The rest of the text remains unchanged from the original report issued in May 2005. CH2M HILL is producing risk/performance assessments to support the closure of single-shell tanks at the DOE's Hanford Site. As part of this effort, staff at PNNL were asked to develop release models for contam¬inants of concern that are present in residual sludge remaining in tank 241-C-106 (C-106) after final retrieval of waste from the tank. This report provides the information developed by PNNL.
Date:
May 23, 2007
Creator:
Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F. & Schaef, Herbert T.
Object Type:
Report
System:
The UNT Digital Library
Hanford Tanks 241-C-203 and 241 C 204: Residual Waste Contaminant Release Model and Supporting Data
This report was revised in May 2007 to correct 90Sr values in Chapter 3. The changes were made on page 3.9, paragraph two and Table 3.10; page 3.16, last paragraph on the page; and Tables 3.21 and 3.31. The rest of the text remains unchanged from the original report issued in October 2004. This report describes the development of release models for key contaminants that are present in residual sludge remaining after closure of Hanford Tanks 241-C-203 (C-203) and 241-C-204 (C-204). The release models were developed from data generated by laboratory characterization and testing of samples from these two tanks. Key results from this work are (1) future releases from the tanks of the primary contaminants of concern (99Tc and 238U) can be represented by relatively simple solubility relationships between infiltrating water and solid phases containing the contaminants; and (2) high percentages of technetium-99 in the sludges (20 wt% in C-203 and 75 wt% in C-204) are not readily water leachable, and, in fact, are very recalcitrant. This is similar to results found in related studies of sludges from Tank AY-102. These release models are being developed to support the tank closure risk assessments performed by CH2M HILL Hanford Group, …
Date:
May 23, 2007
Creator:
Deutsch, William J.; Krupka, Kenneth M.; Lindberg, Michael J.; Cantrell, Kirk J.; Brown, Christopher F. & Schaef, Herbert T.
Object Type:
Report
System:
The UNT Digital Library
Retention and Switching Kinetics of Protonated Gate Field Effect Transistors
The switching and memory retention time has been measured in 50 {micro}m gatelength pseudo-non-volatile memory MOSFETS containing, protonated 40 nm gate oxides. Times of the order of 3.3 seconds are observed for fields of 3 MV cm{sup {minus}1}. The retention time with protons placed either at the gate oxide/substrate or gate oxide/gate electrode interfaces is found to better than 96{percent} after 5,000 seconds. Measurement of the time dependence of the source-drain current during switching provides clear evidence for the presence of dispersive proton transport through the gate oxide.
Date:
May 23, 2000
Creator:
Devine, R. A. B. & Herrera, Gilbert V.
Object Type:
Article
System:
The UNT Digital Library
BACKSCATTER GUAGE DESCRIPTION FOR INSPECTION OF NEUTRON ABSORBER AND UNIFORMITY
This paper describes design, calibration, and testing of a dual He-3 detector neutron backscatter gauge for use in the Savannah River Site Mixed Oxide Fuel project. The gauge is demonstrated to measure boron content and uniformity in concrete slabs used in the facility construction.
Date:
May 23, 2012
Creator:
Dewberry, R.; Gibbs, K. & Couture, A.
Object Type:
Article
System:
The UNT Digital Library
Molecular Weight Distributions of Irradiated Siloxane-Based Elastomers: A Complementary Study by Statistical Modeling and Multiple Quantum Nuclear Magnetic Resonance.
None
Date:
May 23, 2010
Creator:
Dinh, L N; Mayer, B P; Maiti, A; Chinn, S C & Maxwell, R S
Object Type:
Article
System:
The UNT Digital Library
Estimation of Steady-State and Transcient Power Distributions for the RELAP Analyses of the 1963 Loss-Of-Flow and Loss-Of-Pressure Tests at br2.
To support the safety analyses required for the conversion of the Belgian Reactor 2 (BR2) from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, the simulation of a number of loss-of-flow tests, with or without loss of pressure, has been undertaken. These tests were performed at BR2 in 1963 and used instrumented fuel assemblies (FAs) with thermocouples (TC) imbedded in the cladding as well as probes to measure the FAs power on the basis of their coolant temperature rise. The availability of experimental data for these tests offers an opportunity to better establish the credibility of the RELAP5-3D model and methodology used in the conversion analysis. In order to support the HEU to LEU conversion safety analyses of the BR2 reactor, RELAP simulations of a number of loss-of-flow/loss-of-pressure tests have been undertaken. Preliminary analyses showed that the conservative power distributions used historically in the BR2 RELAP model resulted in a significant overestimation of the peak cladding temperature during the transient. Therefore, it was concluded that better estimates of the steady-state and decay power distributions were needed to accurately predict the cladding temperatures measured during the tests and establish the credibility of the RELAP model and methodology. The new approach ('best …
Date:
May 23, 2011
Creator:
Dionne, B. & Tzanos, C. P. (Nuclear Engineering Division)
Object Type:
Report
System:
The UNT Digital Library
Thermal properties for the thermal-hydraulics analyses of the BR2 maximum nominal heat flux.
This memo describes the assumptions and references used in determining the thermal properties for the various materials used in the BR2 HEU (93% enriched in {sup 235}U) to LEU (19.75% enriched in {sup 235}U) conversion feasibility analysis. More specifically, this memo focuses on the materials contained within the pressure vessel (PV), i.e., the materials that are most relevant to the study of impact of the change of fuel from HEU to LEU. This section is regrouping all of the thermal property tables. Section 2 provides a summary of the thermal properties in form of tables while the following sections present the justification of these values. Section 3 presents a brief background on the approach used to evaluate the thermal properties of the dispersion fuel meat and specific heat capacity. Sections 4 to 7 discuss the material properties for the following materials: (i) aluminum, (ii) dispersion fuel meat (UAlx-Al and U-7Mo-Al), (iii) beryllium, and (iv) stainless steel. Section 8 discusses the impact of irradiation on material properties. Section 9 summarizes the material properties for typical operating temperatures. Appendix A elaborates on how to calculate dispersed phase's volume fraction. Appendix B shows the evolution of the BR2 maximum heat flux with burnup.
Date:
May 23, 2011
Creator:
Dionne, B.; Kim, Y. S. & Hofman, G. L. (Nuclear Engineering Division)
Object Type:
Report
System:
The UNT Digital Library
Low-speed wind-tunnel investigation of the longitudinal stability characteristics of a model equipped with a variable-sweep wing
Report presenting an investigation to determine the longitudinal stability characteristics of a complete model equipped with a variable-sweep wing at four different angles of sweepback. The primary objective was to study various wing modifications and an external-flap arrangement designed to minimize the shift in neutral point accompanying the change in sweep angle.
Date:
May 23, 1949
Creator:
Donlan, Charles J. & Sleeman, William C., Jr.
Object Type:
Report
System:
The UNT Digital Library
A review of the Model 5A uranium hexafluoride cylinder
Both the Model 5A (Monel 400) and 5A (Monel 400) Modified five-inch cylinders have been used at the Portsmouth GDP to withdraw, store, and ship highly enriched uranium hexafluoride. As a result of a generic cracking problem with Monel 400 valve-boss material, a cylinder modification was implemented in the mid 1970s. This modification resulted in the violation of the ASME ''Code'' stamp status of the Model 5A Modified cylinder. Hydrostatic testing-to- rupture data indicated that the Model 5A Modified cylinders had ruptured strengths equivalent to that of the original Model 5A cylinders. An independent consultant reviewed the available information and confirmed that the Model 5A Modified cylinders ''will with proper maintenance continue to perform satisfactorily for many additional years of service.'' Based on the test data and consultant's review, DOE approved continued use of the 5A Modified cylinder and also requested procurement of replacement 5B cylinders be expedited. Currently, the 5A modified cylinders are in the production, storage, shipment cycle, and a sufficient number of 5B cylinders has been ordered to accommodate the projected product shipping requirements for the Navy flow. 3 tabs.
Date:
May 23, 1989
Creator:
Dorning, R.E. II
Object Type:
Report
System:
The UNT Digital Library
Wind Powering America: America's Wind Power...A Natural Resource
The Wind Powering America Initiative is a regionally-based effort to increase the use of clean wind energy in the United States over the next two decades. The purpose of this brochure is to provide a brief description of the initiative, its goals, benefits, and strategy as well as a list of contacts for those interested in obtaining more information.
Date:
May 23, 2001
Creator:
Dougherty, P.
Object Type:
Book
System:
The UNT Digital Library
Fiber-Matrix Interface Studies on Electron Beam Cured Composites
The recently completed Department of Energy (DOE) and industry sponsored Cooperative Research and Development Agreement (CRADA) entitled, ''Electron Beam Curing of Polymer Matrix Composites,'' determined that the interlaminar shear strength properties of the best electron beam cured IM7/epoxy composites were 19-28% lower than autoclave cured IM7/epoxy composites (i.e. IM7/977-2 and IM7/977-3). Low interlaminar shear strength is widely acknowledged as the key barrier to the successful acceptance and implementation of electron beam cured composites in the aircraft/aerospace industry. The objective of this work was to improve the interlaminar shear strength properties of electron beam cured composites by formulating and evaluating several different fiber sizings or coating materials. The researchers have recently achieved some promising results by having discovered that the application of epoxy-based, electron beam compatible sizings or coatings onto surface-treated, unsized IM7 carbon fibers improved the composite interlaminar shear strength properties by as much as 55% versus composites fabricated from surface-treated, unsized IM7 fibers. In addition, by applying these same epoxy-based sizings or coatings onto surface-treated, unsized IM7 fibers it was possible to achieve an 11% increase in the composite interlaminar shear strength compared to composites made from surface-treated, GP-sized IM7 fibers. Work is continuing in this area of research …
Date:
May 23, 1999
Creator:
Drazel, L. T.; Janke, C. J. & Yarborough, K. D.
Object Type:
Article
System:
The UNT Digital Library
RATIO OF U-232 TO U-233 PRODUCED IN THE TBR
The production of U/sup 232/ in the cost optimized TBR and oneregion thorlum oxide-uranium oxide slurry reactor has been estimated to be, respectively, 40 and 260 parts per million parts of U/sup 233/ produced. These production rates are compared with corresponding production rates in irradiated thorium rods and found to be comparable. Recommendations are made for increasing the purity of the U/sup 233/ product. (auth)
Date:
May 23, 1955
Creator:
Dresner, L
Object Type:
Report
System:
The UNT Digital Library
The Aerodynamic Characteristics in Pitch of a 1/15-Scale Model of the Grumman F11F-1 Airplane at Mach Numbers of 1.41, 1.61, and 2.01, TED No. NACA DE 390
"Tests have been made in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.41, 1.61, and 2.01 to determine the static longitudinal stability and control characteristics of various arrangements of the Grumman F11F-1 airplane. Tests were made of the complete model and various combinations of its component parts and, in addition, the effects of various body modifications, a revised vertical tail, and wing fences on the longitudinal characteristics were determined" (p. 1).
Date:
May 23, 1956
Creator:
Driver, Cornelius
Object Type:
Report
System:
The UNT Digital Library
Introduction to Python
This report contains viewgraphs on a object-oriented programming language called Python. The basic elements of Python and its new numerical extension are discussed.
Date:
May 23, 1996
Creator:
Dubois, P.F.
Object Type:
Article
System:
The UNT Digital Library
EFFECT OF SURFACE PREPARATION TECHNIQUE ON THE RADIATION DETECTOR PERFORMANCEOF CDZNTE
Synthetic CdZnTe (CZT) semiconducting crystals are highly suitable for the room temperature-based detection of gamma radiation. The surface preparation of Au contacts on surfaces of CZT detectors is typically conducted after (1) polishing to remove artifacts from crystal sectioning and (2) chemical etching, which removes residual mechanical surface damage however etching results in a Te rich surface layer that is prone to oxidize. Our studies show that CZT surfaces that are only polished (as opposed to polished and etched) can be contacted with Au and will yield lower surface currents. Due to their decreased dark currents, these as-polished surfaces can be used in the fabrication of gamma detectors exhibiting a higher performance than polished and etched surfaces with relatively less peak tailing and greater energy resolution. CdZnTe or ''CZT'' crystals are attractive to use in homeland security applications because they detect radiation at room temperature and do not require low temperature cooling as with silicon- and germanium-based detectors. Relative to germanium and silicon detectors, CZT is composed of higher Z elements and has a higher density, which gives it greater ''stopping power'' for gamma rays making a more efficient detector. Single crystal CZT materials with high bulk resistivity ({rho}>10{sup 10} …
Date:
May 23, 2007
Creator:
Duff, M
Object Type:
Article
System:
The UNT Digital Library
Taiwan: Recent Developments and U.S. Policy Choices
This report focuses on current developments in Taiwan, analyzing how those developments are affecting choices the United States makes about its policy toward Taiwan specifically and toward the People's Republic of Chine (PRC) more broadly.
Date:
May 23, 2008
Creator:
Dumbaugh, Kerry
Object Type:
Report
System:
The UNT Digital Library