Search Results

open access

FINAL STATUS OF GENERAL ENGINEERING LABORATORY AIR FLOW AND DUST TEST PROGRAM. PART I. PART II

Description: A full scale 15 deg sector of the P122 reactor configuration was constructed. The model was complete with respect to all internal cooling air passages, and reflectors, thermal shielding, and island reflector. The contract was terminated before any test data could be obtained. Investigation of the effect of atmospheric dust on performance of reactor systems using wire screen matrix fuel elements is reported. The interim conclusion is that dust would not limit aircraft performance or life. Work proposed but not completed is outlined. Appendices contain previously unpublished reports. (auth)
Date: May 25, 1961
Creator: Venneman, W.F.; Lawrence, R.L. & Ryan, P.T.
Partner: UNT Libraries Government Documents Department
open access

The development of precipitated iron catalysts with improved stability

Description: The objective of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors. The performance targets are 88% CO+H{sub 2} conversion with less than 1% deactivation/day for 1 month and a methane and ethane selectivity of no more than 7% (based on hydrocarbons and oxygenates only) at a space velocity of at least 2 normal liters per hr per gram iron (NL/hr/gFe) using a synthesis gas with 0.5-1.0 H{sub 2}:CO ratio in a slurry reactor.
Date: May 6, 1992
Creator: Abrevaya, H.
Partner: UNT Libraries Government Documents Department
open access

Bacterial Challenge in Lumbricus Terrestris: A Terrestrial Invertebrate Immunotoxicity Model.

Description: A bacterial challenge assay was developed utilizing the earthworm, Lumbricus terrestris, in order to assess potential immunotoxic effects from exposure to specific polychlorinated biphenyl congeners. Earthworms were inoculated with Aeromonous hydrophila, establishing a 10-day LD50. In vitro assays for effects of PCBs on phagocytosis agreed with mammalian studies, demonstrating potent suppression of phagocytosis by the non-coplanar PCB congener 138 and no suppression by the coplanar congener 126. However, when the effects of the two PCB congeners were evaluated for suppression of resistance to a whole animal infection challenge assay, coplanar PCB 126 decreased the ability of L. terrestris to withstand infection while non-coplanar PCB 138 did not.
Date: May 2007
Creator: McDonald, Jennifer C.
Partner: UNT Libraries
open access

Resource capture by single leaves

Description: Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.
Date: May 1, 1992
Creator: Long, S.P.
Partner: UNT Libraries Government Documents Department
open access

Importance of the specific heat anomaly in the design of binary Rankine cycle power plants

Description: The transposed critical temperature (TPCT) is shown to be an extremely important thermodynamic property in the selection of working fluids and turbine states for geothermal power plants operating on a closed organic (binary) Rankine cycle. When the optimum working fluid composition and process states are determined for specified source and sink conditions, turbine inlet states consistently lie adjacent to the working fluids' TPCT line for all resource temperatures, constraints, and cost and efficiency factors investigated.
Date: May 1, 1980
Creator: Pope, W.L.; Doyle, P.A.; Fulton, R.L. & Silvester, L.F.
Partner: UNT Libraries Government Documents Department
open access

Aerial radiometric and magnetic survey, San Angelo National Topographic Map: Texas, West Texas Project. Final report

Description: The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the San Angelo National Topographic Map NH14-1 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium, and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included.
Date: May 1, 1980
Partner: UNT Libraries Government Documents Department
open access

An update on passive correctors for the SSC dipole magnets

Description: The concept of correction of the magnetization sextupole became a topic of discussion as soon as it was realized that superconductor magnetization could have a serious effect on the SSC beam during injection. Several methods of correction were proposed. These included (1) correction with active bore tube windings like those on the HERA machine which correct out magnetization sextupole and the sextupole due to iron saturation, (2) correction with persistent sextupole windings mounted on the bore tube (3) correction using passive superconductor (4) correction using ferromagnetic material, and (5) correction using oriented magnetized materials. This report deals with the use of passive superconductor to correct the magnetization sextupole. Two basic methods are explored in this report: (1) One can correct the magnetization sextupole by changing the diameter of the superconductor filaments in one or more blocks of the SSC dipole. (2) One can correct the magnetization sextupole and decapole by mounting passive superconducting wires on the inside of the SSC dipole coil bore. In addition, an assessment of the contribution of each conductor in the dipole to the magnetization sextupole and decapole is shown. 38 refs, 25 figs., 15 tabs.
Date: May 1, 1991
Creator: Green, Michael A.
Partner: UNT Libraries Government Documents Department
open access

EFFECT OF URANIUM-BEARING SCALE DEPOSITS ON HRE-2 CORE WALL TEMPERATURE, HEAT FLUX, AND PATCH TEMPERATURE

Description: Calculations are presented to show the effect of uraniumbearing scale deposits on the HRE-2 core wall tempera ture, heat flux, and the temperature. of patches proposed for sealing the holes of the HRE-2 core vessel. Flow behavior in the HRE-2 core mockup with simulated patches installed and simulated corrosion pits drilled in the vessel wall was determined. A plausible mechanism was advanced to account for hot spots due to sedimentation of solids on metal surfaces projecting from the core wall. Patch designs with reduced metal projections from the core wall are presented. (auth)
Date: May 29, 1962
Creator: Lawson, C.G. & Peebles, F.N.
Partner: UNT Libraries Government Documents Department
open access

Creating a word list for technical and clerical personnel

Description: The Savannah River Plant and Laboratory employ more than 16,000 people. When the separate Publications Divisions of the Plant and Laboratory were combined it was determined that a single source of information for using terms was needed, and that the source would take the form of a word list. The Word List was issued to more than 5000 employees onsite. In addition, the Word List is being added to the site computer network as a reference document and as an online spelling checker where more than 2000 employees will have access to it through their personal computers.
Date: May 1, 1988
Creator: Hammond, J S
Partner: UNT Libraries Government Documents Department
open access

Organic Nuclear Reactors: An Evaluation of Current Development Programs

Description: Organic reactor technology is critically evaluated and areas of research and development work now lacking or inadequate for the successful development of this reactor concept are indicated. The development programs for present organic and heavy water moderated concepts appear generally adequate to reach specific goals. However, the narrow scope of the organic reactor program should be broadened to assure coverage of areas where the application of novel principles might result in marked economic benefits. Further work, principally of a basic nature, is recommended in the fields of chemistry, processing, management, and thermodynamic properties of coolants, in fuel development, and in concept evaluation. (N.W.R.)
Date: May 1, 1961
Partner: UNT Libraries Government Documents Department
open access

The Electrical Resistivity of Molten and Solid Thorium-Magnesium Eutetic

Description: Electrical resistivity properties of polycrystalline 39 wt % thorium-- magnesium eutectic are reported for the solid from room temperature to its melting point at 589 deg C and as a liquid from its melting point to 900 deg C. The electrical resistivity of the eutectic at the melting point was 69.5 microhm- centimeters; it decreased to a value of 64.8 microhm-centimeters at 900 C. Tantalum tubing was used to contain the alloy in the molten state. (auth)
Date: May 1, 1962
Creator: Provow, D. M. & Fisher, R. W.
Partner: UNT Libraries Government Documents Department
open access

The use of democratic institutions as a strategy to legitimize authoritarian rule.

Description: Numerous authoritarian states use institutions usually associated with democratic regimes like a constitution, elections, and a legislature. This seems to be counterintuitive. Authoritarian regimes should rather shrink away from democratic institutions. Elections can be won by the opposition and legislatures can make decisions against the interests of the ruler. So, why do autocratic regimes install institutions which limit their power and threaten their survival in office? Assuming actors behave rationally, one should expect authoritarian rulers only to introduce procedures working in their favor. This study looks at the effect of institutions in authoritarian regimes. The findings suggest that legislatures significantly lower the chances of regime breakdown in the long run. However, particularly in election years, authoritarian regimes are facing a higher likelihood of failure.
Date: May 2007
Creator: Michalik, Susanne
Partner: UNT Libraries
open access

A Method for Determining Allowable Residual Contamination Levels of Radionuclide Mixtures in Soil

Description: An important consideration in the disposal of radioactive wastes, and consequently in the preparation of plans for remedial actions at contaminated sites, is the amount of radioactive contamination that may be allowed to remain at any particular waste site. The allowable residual contamination level (ARCL) is dependent on the radiation dose limit imposed, the physical and environmental characteristics of the waste site, and the time at which exposure to the wastes is assumed to occur. The steps in generating an ARCL are generally as follows: (1) develop plausible, credible site-specific exposure scenario; (2) calculate maximum annual radiation doses to an individual for each radionuclide based on the existing physical characteristics of the waste site and the site-specific exposure scenario; (3) calculate the ARCL for the dose limit desired, including all radionuclides present, uncorrected for site cleanup or barrier considerations; and (4) apply any corrections for proposed cleanup activity or addition of barriers to waste migration or uptake to obtain the ARCL applicable to the proposed action. Use of this method allows appropriate application of resources to achieve uniform compliance with a single regulatory standard, i.e., a radiation dose rate limit. Application and modification of the ARCL method requires appropriate models of the environmental transport and fate of radionuclides. Example calculations are given for several specific waste forms and waste site types in order to demonstrate the technique and generate comparisons with other approaches.
Date: May 1, 1982
Creator: Napier, B .A.
Partner: UNT Libraries Government Documents Department
open access

A Program of FRC Theory Research Annual Report

Description: At the request of the Office of Fusion Energy, a group of experts was convened on February 6--8, 1990. This group met to assess the world data base on Reversed Field Pinch (RFP) physics, and, further, to assess the role of the ZTH experiment in providing reactor relevant physics understanding for that confinement geometry. This group met, analyzed some of the relevant literature, and heard extensive presentations on the physics of the RFP and the plans for the ZTH and RFX devices. The conclusions of this group of experts are contained in this report.
Date: May 18, 1990
Creator: Krall, Nicholas A.
Partner: UNT Libraries Government Documents Department
open access

Dye-laser development for plasma magnetic-field diagnostic

Description: A flash-lamp-pumped dye laser has been constructed and operated in DCM dye, yielding outputs greater than 400 W for 100 ..mu..s in broadband operation. Attempts to tune this laser by injection locking to a narrow-band cw laser poor efficiency and relatively short locked operation.
Date: May 1, 1982
Creator: Weber, P.G.
Partner: UNT Libraries Government Documents Department
open access

Site Specific Verification Guidelines.

Description: The Bonneville Power Administration (BPA) and the Northwest region have moved from energy surplus to a time when demand for energy is likely to exceed available supplies. The Northwest Power Planning Council is calling for a major push to acquire new resources.'' To meet anticipated loads in the next decade, BPA and the region must more than double that rate at which we acquire conservation resources. BPA hopes to achieve some of this doubling by programs independently designed and implemented by utilities and other parties without intensive BPA involvement. BPA will accept proposals for programs using performance-based payments, in which BPA bases its reimbursement to the sponsor on measured energy savings rather than program costs. To receive payment for conservation projects developed under performance-based programs, utilities and other project developers must propose verification plans to measure the amount of energy savings. BPA has traditionally used analysis of billing histories, before and after measure installation, adjusted by a comparison group on non-participating customers to measure conservation savings. This approach does not work well for all conversation projects. For large or unusual facilities the comparison group approach is not reliable due to the absence of enough comparable non-participants to allow appropriate statistical analysis. For these facilities, which include large commercial and institutional buildings, industrial projects, and complex combinations of building types served by a single utility meter, savings must be verified on a site-specific basis. These guidelines were written to help proposers understand what Bonneville considers the important issues in site specific verification of conservation performance. It also provides a toolbox of methods with guidance on their application and use. 15 refs.
Date: May 1, 1992
Creator: Harding, Steve; Gordon, Frederick M. & Kennedy, Mike
Partner: UNT Libraries Government Documents Department
open access

Repair Welding of Fusion Reactor Components

Description: Recent experimental investigations indicate that the repair welding of irradiated materials containing greater than 1 to 2.5 appm helium leads to catastrophic cracking in the heat affected zone of the weld. The high temperatures and cooling tensile stresses which occur during the welding process lead to enhanced helium bubble growth in the heat affected zone region, resulting in catastrophic cracking upon cooling. An investigation is proposed which seeks to determine the effect of stress state on the helium bubble growth process and develop engineering modifications to the welding process based upon this understanding in an attempt to alleviate or eliminate the weld cracking problem in type 316 stainless steel materials.
Date: May 20, 1992
Creator: Chin, Bryan A.
Partner: UNT Libraries Government Documents Department
open access

The Geologic and Archaeological History of the Dickie Carr Site 41PR26

Description: This thesis is an analysis and synthesis of the geologic and archaeological history of the Dickie Carr site, 41PR26, on Mill Creek in north central Texas. Included are analyses of the stratigraphy, sedimentary environments, and soils of the locality. A regional comparison is made with respect to the Late Quaternary geology of the upper Trinity River basin, Texas to interpret the geologic data. Two stratigraphic units were identified that record the Pleistocene-Holocene transition. The buried lower unit is comprised of terrace, floodplain, and channel deposits with extensive pedogenesis. The unit is Late Pleistocene in age and contains the remains of Mammuthus columbi. The upper stratigraphic unit is comprised of terrace and floodplain sediments with well-expressed pedogenesis. The unit is Early Holocene in age with Late Paleoindian and Late Archaic occupations. The archaeological components are compared and contrasted with documented sites from the Elm and East Forks of the Trinity River. The occupations are examined in a geoarchaeological context. The Late Paleoindian occupation is post-depositional and located in terrace deposits. The Late Archaic occupation is syndepositional and located in floodplain deposits.
Date: May 2007
Creator: Byers, Johnny A.
Partner: UNT Libraries
open access

Applying Cognitive Load Theory to the Design of Online Learning.

Description: The purpose of the study was to investigate the application of cognitive load theory to the design of online instruction. Students in three different courses (N = 146) were measured on both learning performance and perceptions of mental effort to see if there were any statistically significant differences. The study utilized a quasi-experimental posttest-only control group design contrasting modified and unmodified instructional lessons. Both groups were given a posttest to measure knowledge gained from the lesson (cognitive domain of learning) and perceptions of mental effort involved. Independent samples t-tests were used to compare the mean performance scores of the treatment groups (i.e. the sections using redesigned materials) versus the control groups for all three courses. Cohen's d was also computed to determine effect size. Mental effort scores were similarly compared for each group on the overall cognitive load score, for a total of six data points in the study. Of the four hypotheses examined, three (H1, H2, H4) found no statistically significant difference between the experimental and control groups. Negative significance was found between the experimental and control group on the effect of modality (H3). On measures of cognitive load, no statistically significant differences were found.
Date: May 2007
Creator: Burkes, Kate M. Erland
Partner: UNT Libraries
open access

PSI radiative decays

Description: Inclusive and exclusive measurements of psi radiative decay are presented. The magnitude of hard inclusive radiative decay is comparable to the prediction f first order QCD, but the measured spectrum is considerably softer. In addition to measurements of radiative decays to the known pseudoscalar and tensor mesons, a sizable decay to a resonance of mass 1440/sub -15//sup +10/ MeV/c/sup 2/ in the K anti K..pi.. mode is observed. This may be the E(1420) meson. Supporting evidence is presented for the existence of the n/sub c/ at a mass of 2980 MeV/c/sup 2/.
Date: May 1, 1980
Creator: Feldman, G. J.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen