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Managing in an environmentally constrained world
In thinking about this issue, one comes to fundamental question: Why are we concerned at all? Why have all of us gathered here, rather than simply continue to clean up what we should from the past and control our emissions for the present and the future? The answer, I think, may be hinted at by several scenarios (which, although plausible given current trends, are intended to be hypothetical).
Date:
September 25, 1995
Creator:
Allenby, B.R.
Object Type:
Article
System:
The UNT Digital Library
Optical Properties of InGaAsN: A New 1eV Bandgap Material System
InGaAsN is a new semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the bandgap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low temperature photohnninescence energy of the material for pressures between ambient and 110 kbar. We describe a simple, density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low concentration alloys. The theoretically predicted pressure dependence of the bandgap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for the strongly non-linear pressure dependence of the bandgap that, surprisingly, does not involve a nitrogen impurity band. Addhionally, conduction-band mass measurements, measured by three different techniques, will be described and finally, the magnetoluminescence determined pressure coefficient for the conduction-band mass is measured.
Date:
January 25, 1999
Creator:
Allerman, A. A.; Fritz, I. J.; Jones, E. D.; Kurtz, S. R.; Modine, N. A.; Tozer, S. T. et al.
Object Type:
Article
System:
The UNT Digital Library
Can Cavitation Be Anticipated?
The major problem with cavitation in pumps and hydraulic systems is that there is no effective (conventional) method for detecting or predicting its inception. The traditional method of recognizing cavitation in a pump is to declare the event occurring when the total head drops by some arbitrary value (typically 3%) in response to a pressure reduction at the pump inlet. However, the device is already seriously cavitating when this happens. What is actually needed is a practical method to detect impending rather than incipient cavitation. Whereas the detection of incipient cavitation requires the detection of features just after cavitation starts, the anticipation of cavitation requires the detection and identification of precursor features just before it begins. Two recent advances that make this detection possible. The first is acoustic sensors with a bandwidth of 1 MHz and a dynamic range of 80 dB that preserve the fine details of the features when subjected to coarse vibrations. The second is the application of Bayesian parameter estimation which makes it possible to separate weak signals, such as those present in cavitation precursors, from strong signals, such as pump vibration. Bayesian parameter estimation derives a model based on cavitation hydrodynamics and produces a figure …
Date:
April 25, 1999
Creator:
Allgood, G. O.; Dress, W. B.; Hylton, J. O. & Kercel, S. W.
Object Type:
Article
System:
The UNT Digital Library
Cultivator Attachment
Patent for a cultivator attachment. Illustrations included.
Date:
October 25, 1904
Creator:
Allgood, Walton P. & Allgood, Joseph P.
Object Type:
Patent
System:
The Portal to Texas History
Supersonic Technology for CO2 Capture
Advanced Research Projects Agency-Energy project sheet summarizing general information about the Innovative Materials and Processes for Advanced Carbon Capture Technologies (IMPACCT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses the development of a new device as part of the "A High Efficiency Inertial CO2 Extraction System" project.
Date:
May 25, 2012
Creator:
Alliant Techsystems
Object Type:
Text
System:
The UNT Digital Library
Comments on septa and other small production angle magnets
A discussion is given of possible septum magnet parameters for small production angle experiments in the ISABELLE storage rings. Superconducting septa and torroidal septa are also considered. (PMA)
Date:
August 25, 1977
Creator:
Allinger, J.; Danby, G. & Jackson, J.
Object Type:
Article
System:
The UNT Digital Library
Reactive Multiphase Behavior of CO2 in Saline Aquifers Beneath the Colorado Plateau
Field and laboratory investigations of naturally occurring CO{sub 2}-reservoirs are being conducted to determine the characteristics of potential seal and reservoir units and the extent of the interactions that occur between the host rocks and the CO{sub 2} charged fluids. Efforts have focused on the Farnham Dome field, located in central Utah, the Springerville-St. Johns field in Arizona and New Mexico, and most recently, the Crystal Geyser-Salt Wash graben areas with their CO{sub 2}-charged geysers and springs in central Utah. At both the Springerville-St. Johns field and the central Utah CO{sub 2} spring area, there is evidence of extensive travertine deposits that document release of CO{sub 2} to the atmosphere. At Farnham Dome, calcite debris fields appear to be remnants of vein calcite and an earlier period of fluid leakage. The main achievements during this quarter are (1): preparation for a soil gas flux survey in October at the Crystal Geyser --Little Grand Wash fault zone, and the Salt Wash graben; (2) submission of an abstract to the upcoming Measurement, Monitoring and Verification session at the Fall AGU meeting; (3) submission of an invited abstract to the Gordon Conference on Hydrocarbon Resources; and (4) receipt of initial radiocarbon dates of …
Date:
October 25, 2004
Creator:
Allis, R. G.; Moore, J. & White, S.
Object Type:
Report
System:
The UNT Digital Library
Improvement in Devices for Teaching Musical Transposition.
Patent for an improvement in devices for teaching musical transposition. The invention in question is composed of a keyboard "with sliding instruments and scales" (1).
Date:
April 25, 1876
Creator:
Allison, Thomas J.
Object Type:
Patent
System:
The Portal to Texas History
Numerical studies of mass transfer and accretion in x-ray binary systems
None
Date:
September 25, 1974
Creator:
Alme, M.L.
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
DISTRIBUTION COEFICIENTS (KD) GENERATED FROM A CORE SAMPLE COLLECTED FROM THE SALTSTONE DISPOSAL FACILITY
Core samples originating from Vault 4, Cell E of the Saltstone Disposal Facility (SDF) were collected in September of 2008 (Hansen and Crawford 2009, Smith 2008) and sent to SRNL to measure chemical and physical properties of the material including visual uniformity, mineralogy, microstructure, density, porosity, distribution coefficients (K{sub d}), and chemical composition. Some data from these experiments have been reported (Cozzi and Duncan 2010). In this study, leaching experiments were conducted with a single core sample under conditions that are representative of saltstone performance. In separate experiments, reducing and oxidizing environments were targeted to obtain solubility and Kd values from the measurable species identified in the solid and aqueous leachate. This study was designed to provide insight into how readily species immobilized in saltstone will leach from the saltstone under oxidizing conditions simulating the edge of a saltstone monolith and under reducing conditions, targeting conditions within the saltstone monolith. Core samples were taken from saltstone poured in December of 2007 giving a cure time of nine months in the cell and a total of thirty months before leaching experiments began in June 2010. The saltstone from Vault 4, Cell E is comprised of blast furnace slag, class F fly …
Date:
April 25, 2011
Creator:
Almond, P. & Kaplan, D.
Object Type:
Report
System:
The UNT Digital Library
Fabrication and Characterization of Borosilicate Glasses Containing Alpha-Radionuclides and Silver From Conversion and Mixed-Oxide Facilities Proposed for Russia
Liquid and solid radioactive wastes are formed during conversion of plutonium metal to oxide and during fabrication of weapons-grade plutonium into mixed-oxide (MOX) fuel. In Russia, these wastes are to be processed for disposition by immobilization in either borosilicate glass or cement matrices depending upon the waste stream-specific radionuclide contents. Vitrification is planned for the liquid high-level waste raffinate stream containing the bulk of the Am-241 produced from Pu-241 decay. Previous work on the Russian MOX Fuel Fabrication Facility (R-MFFF) by the Public Joint Stock Corporation (TVEL) [1] showed that this waste stream may contain significant amounts of silver derived from the electrochemical dissolution of PuO2 using a Ag(II) catalyst. The work reported here further investigated silver solubility limits, which, if exceeded in a production glass melter, allow discrete silver grains to form in the glass and also deposit over time on the bottom of a joule-heated ceramic melter. In melters with immersed electrodes, such as the Russian EP-100 for phosphate glasses or the US Duratek DP-100 type melters for borosilicate glasses that are being considered for use at the Siberian Chemical Combine (SCC) Tomsk site, the undissolved silver could cause a short circuit and an unacceptable production melter failure. …
Date:
October 25, 2005
Creator:
Aloy, Albert S.; Trofimenko, Alexander V.; Uspensky, Alexander I. & Jardine, Leslie J.
Object Type:
Article
System:
The UNT Digital Library
The [Sigma/Alpha] Branching Ratio Of [Y*1]
Recently a T=1 resonance in the [Alpha w] system called [Y*1] has been observed with a mass of 1385 Mev. Two types of resonances have been predicted that might relate this observation to other elementary-particle interactions: (1) P 3/2 resonances in the Alpha w and Sigma w systems predicted by global symmetry corresponding to the (3/2, 3/2) resonance of the wN system, (2) a spin-1/2 Y-w resonance resulting from a bound state in the KN system. The position and width of the observed [Y*1] resonance agree with both theories but since the spin and parity have not yet been determined, it is impossible at present to distinguish between the two theoretical interpretations.
Date:
April 25, 1961
Creator:
Alston, Margaret H.; Alvarez, Luis W., 1911-1988; Eberhard, Phillippe; Good, Myron L.; Graziano, William; Ticho, Harold K., 1921-2020 et al.
Object Type:
Report
System:
The UNT Digital Library
THE Epsilon*/Lambda BRANCHING RATIO OF Y*1
Recently a T = 1 resonance in the {Lambda}{pi} system called Y*{sub 1} has been observed with a mass of 1385 Mev. Two types of resonances have been predicted that might relate this observation to other elementary-particle interactions: (1) P 3/2 resonances in the {Lambda}{pi} and {Sigma}{pi} systems predicted by global symmetry corresponding to the (3/2, 3/2) resonance of the {pi}N system; (2) a spin-1/2 Y-{pi} resonance resulting from a bound state in the KN system. The position and width of the observed Y*{sub 1} resonance agree with both theories, but since the spin and parity have not yet been determined, it is impossible at present to distinguish between the two theoretical interpretations.
Date:
April 25, 1961
Creator:
Alston, Margaret H.; Alvarez, Luis W.; Eberhard, Philippe; Good,Myron L.; Graziano, William; Ticho, Harold K. et al.
Object Type:
Article
System:
The UNT Digital Library
Embodied Energy and Off-Grid Lighting
The greenhouse gas (GHG) emissions from fuel-based lighting are substantial given the paltry levels of lighting service provided to users, leading to a great opportunity for GHG mitigation byencouraging the switch from fuel-based to rechargeable LED lighting. However, as with most new energy technology, switching to efficient lighting requires an up-front investment of energy(and GHGs) embedded in the manufacture of replacement components. We studied a population of off-grid lighting users in 2008-2009 in Kenya who were given the opportunity to adopt LEDlighting. Based on their use patterns with the LED lights and the levels of kerosene offset we observed, we found that the embodied energy of the LED lamp was"paid for" in only one month for grid charged products and two months for solar charged products. Furthermore, the energyreturn-on investment-ratio (energy produced or offset over the product's service life divided by energy embedded) for off-grid LED lighting ranges from 12 to 24, which is on par with on-gridsolar and large-scale wind energy. We also found that the energy embodied in the manufacture of a typical hurricane lantern is about one-half to one-sixth of that embodied in the particular LEDlights that we evaluated, indicating that the energy payback time would be …
Date:
January 25, 2011
Creator:
Alstone, Peter; Mills, Evan & Jacobson, Arne
Object Type:
Report
System:
The UNT Digital Library
Interim report on nuclear waste depository thermal analysis
A thermal analysis of a deep geologic depository for spent nuclear fuel is being conducted. The TRUMP finite difference heat transfer code is used to analyze a 3-dimensional model of the depository. The model uses a unit cell consisting of one spent fuel canister buried in salt beneath a ventilated room in the depository. A base case was studied along with several parametric variations. It is concluded that this method is appropriate for analyzing the thermal response of the system, and that the most important parameter in determining the maximum temperatures is the canister heat generation rate. The effects of room ventilation and different depository media are secondary.
Date:
July 25, 1978
Creator:
Altenbach, T.J.
Object Type:
Report
System:
The UNT Digital Library
INDEPENDENT CONFIRMATORY SURVEY SUMMARY AND RESULTS FOR THE FORD NUCLEAR REACTOR, ANN ARBOR, MICHIGAN
At the NRC�s request, ORAU conducted confirmatory surveys of the FNR during the period of December 4 through 6, 2012. The survey activities included visual inspections and measurement and sampling activities. Confirmatory activities also included the review and assessment of UM�s project documentation and methodologies. Surface scans identified elevated activity in two areas. The first area was on a wall outside of Room 3103 and the second area was in the southwest section on the first floor. The first area was remediated to background levels. However, the second area was due to gamma shine from a neighboring source storage area. A retrospective analysis of UM�s FSS data shows that for the SUs investigated by the ORAU survey team, UM met the survey requirements set forth in the FSSP. The total mean surface activity values were directly compared with the mean total surface activity reported by UM. Mean surface activity values determined by UM were within two standard deviations of the mean determined by ORAU. Additionally, all surface activity values were less than the corresponding gross beta DCGLW. Laboratory analysis of the soil showed that COC concentrations were less than the respective DCGLW values. For the inter-lab comparison, the DER was …
Date:
July 25, 2013
Creator:
Altic, Nick A.
Object Type:
Report
System:
The UNT Digital Library
Testing the Concept of Drift Shadow With X-Ray Absorption Imaging Experiments
None
Date:
April 25, 2006
Creator:
Altman, S.J.
Object Type:
Presentation
System:
The UNT Digital Library
An Investigation of Cross-Borehole Ground Penetrating Radar Measurements for Characterizing the 2D Moisture Content Distribution in the Vadose Zone
The use of cross-borehole ground penetrating radar (GPR) imaging for determining g the two dimensional (2D) in situ moisture content distribution within the vadose zone is being investigated. The ultimate goal is to use the GPR images as input to a 2D hydrologic inversion scheme for recovering the van Genuchten parameters governing unsaturated ,hydraulic flow. Initial experiments conducted on synthetic data have shown that at least in theory, cross-borehole GPR measurements can provide realistic estimates of the spatial variation in moisture content that are needed for this type of hydrologic inversion scheme. However, the method can not recover exact values of moisture content due to the break down of the empirical expression often employed to convert GPR velocity images to moisture content, and to the smearing nature of the imaging algorithm. To test the applicability of this method in a real world environment cross- borehole GPR measurements were made at a hydrologic/geophysical vadose zone test site in Socorro, New Mexico. Results show that the GPR images compare well with the uncalibrated borehole neutron log data. GPR data acquisition will continue once an infiltration test has started, and the results from these measurements will be employed in a 2D hydrologic inverse …
Date:
January 25, 1999
Creator:
Alumbaugh, D. & Paprocki, L.
Object Type:
Article
System:
The UNT Digital Library
Final report [The 15th Workshop on Electromagnetic Induction in the Earth, held 8/20-26/2000, and The 5th Magnetotelluric Data Interpretation Workshop, 8/17-19/2000]
This document reports on how the DOE helped to support travel of students and scientists to the conferences in Brazil. Attendee names, funding, and session titles are listed.
Date:
June 25, 2002
Creator:
Alumbaugh, David L.
Object Type:
Report
System:
The UNT Digital Library
Fire protection countermeasures for containment ventilation systems
The goal of this project is to find countermeasures to protect High Efficiency Particulate Air (HEPA) filters, in exit ventilation ducts, from the heat and smoke generated by fire. Initially, methods were developed to cool fire-heated air by fine water spray upstream of the filters. It was recognized that smoke aerosol exposure to HEPA filters could also cause disruption of the containment system. Through testing and analysis, several methods to partially mitigate the smoke exposure to the HEPA filters were identified. A continuous, movable, high-efficiency prefilter using modified commercial equipment was designed. The technique is capable of protecting HEPA filters over the total time duration of the test fires. The reason for success involved the modification of the prefiltration media. Commercially available filter media has particle sorption efficiency that is inversely proportional to media strength. To achieve properties of both efficiency and strength, rolling filter media were laminated with the desired properties. The approach was Edisonian, but truncation in short order to a combination of prefilters was effective. The application of this technique was qualified, since it is of use only to protect HEPA filters from fire-generated smoke aerosols. It is not believed that this technique is cost effective in …
Date:
August 25, 1980
Creator:
Alvares, N.; Beason, D.; Bergman, V.; Creighton, J.; Ford, H. & Lipska, A.
Object Type:
Report
System:
The UNT Digital Library
The Effect of Absorption Systems on Cosmic Reionization
None
Date:
October 25, 2013
Creator:
Alvarez, Marcelo A. & Abel, Tom
Object Type:
Article
System:
The UNT Digital Library
Commercial oxide paints as coatings for SiGe thermoelectric materials
Silicon-germanium alloys are used as thermoelectric materials for radioisotope thermoelectric generators. One problem is the loss of the alloy by sublimation. In the Unicouple, sublimation was minimized by a Si/sub 3/N/sub 4/ coating. In the Multicouple design the application of Si/sub 3/N/sub 4/ coatings which is done at high temperature is not practical. Suppression of sublimation in the Multicouple design is presently accomplished by applying glass coatings. The difficulties encountered with the glass coatings are associated with the poor adherence of the coatings. In the present study, commercial oxide points (mainly ZrO/sub 2/) which have low thermal expansion coefficients are used as coating materials. No spalling from the surface of the coated sample occurred in 1506 hours at 1080/sup 0/C in vacuum, and sublimation was reduced significantly. Zirconium silicate was observed on the surface by x-ray diffraction.
Date:
August 25, 1986
Creator:
Amano, T.; Beaudry, B. J. & Gschneidner, K. A., Jr.
Object Type:
Article
System:
The UNT Digital Library
Studies of hadron-electron separators for the ZEUS barrel calorimeter
Two possible upgrades, a shower maximum detector and a presampler, designed to improve the low energy electron/hadron separation capabilities of the ZEUS barrel calorimeter are described and test-beam results are reported. The presampler can also be used to correct for energy loss of particles traversing the dead material in front of the calorimeter.
Date:
May 25, 1995
Creator:
Ambats, I.; Bortz, D. & Connolly, A.
Object Type:
Report
System:
The UNT Digital Library
Architects of the Capitol: Selected Biographical Information
This report gives a history of the Architect of the Capitol (AOC) position and brief descriptions of past Architects.
Date:
September 25, 2007
Creator:
Amer, Mildred
Object Type:
Report
System:
The UNT Digital Library