Degree Department

Degree Discipline

Degree Level

604 Matching Results

Results open in a new window/tab.

Record of Technical Change No.2 for ``Corrective Action Investigation Plan for Corrective Action Unit 143: Area 25 Contaminated Waste Dumps, Nevada Test Site, Nevada'' (open access)

Record of Technical Change No.2 for ``Corrective Action Investigation Plan for Corrective Action Unit 143: Area 25 Contaminated Waste Dumps, Nevada Test Site, Nevada''

This Record of Technical Change provides updates to the technical information included in ``Corrective Action Investigation Plan for Corrective Action Unit 143: Area 25 Contaminated Waste Dumps, Nevada Test Site, Nevada.''
Date: November 19, 1999
Creator: /NV, USDOE
Object Type: Report
System: The UNT Digital Library
Calorimeter Preamplifier Hybrid Circuit Test Jig (open access)

Calorimeter Preamplifier Hybrid Circuit Test Jig

There are two ways in which the testing may be initiated, remotely or locally. If the remote operation is desired, an external TTL level signal must be provided to the test jig with the remotellocal switch on the side of the test jig switched to remote. A logic high will initiate the test. A logic low will terminate the test. In the event that an external signal is connected to the test jig while local operation occurs, the local control takes precedence over remote control. Once a DVT has been locked in the ZIF socket and the DIP switches are selected, the Push-to-Test button may be depressed. Momentarily depressing the button will initiate a test with a minimum 400 ms duration. At the same time a PBCLOCK and PBLATCH pulses will be initiated and the power rails +12V, +8V, and -6V will be ramped to full voltage. The time at which the power rails reach the full voltage is about 13 ms and it is synchronized with bypass capacitors placed on COMP input of U20 and U22 and on the output of U23 voltage regulators. The voltage rails are supplied to a {+-}10% window comparator. A red LED indicates the …
Date: April 19, 1999
Creator: Abraham, Benjamin M.
Object Type: Report
System: The UNT Digital Library
Sensitivity of natural gas HCCI combustion to fuel and operating parameters using detailed kinetic modeling (open access)

Sensitivity of natural gas HCCI combustion to fuel and operating parameters using detailed kinetic modeling

This paper uses the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to analyze natural gas HCCI combustion in an engine. The HCT code has been modified to better represent the conditions existing inside an engine, including a wall heat transfer correlation. Combustion control and low power output per displacement remain as two of the biggest challenges to obtaining satisfactory performance out of an HCCI engine, and these are addressed in this paper. The paper considers the effect of natural gas composition on HCCI combustion, and then explores three control strategies for HCCI engines: DME (dimethyl ether) addition, intake heating and hot EGR addition. The results show that HCCI combustion is sensitive to natural gas composition, and an active control may be required to compensate for possible changes in composition. The three control strategies being considered have a significant effect in changing the combustion parameters for the engine, and should be able to control HCCI combustion.
Date: July 19, 1999
Creator: Aceves, S.; Dibble, R.; Flowers, D.; Smith, J. R. & Westbrook, C. K.
Object Type: Article
System: The UNT Digital Library
Development of Basic Housing Systems for Maximum Affordability (open access)

Development of Basic Housing Systems for Maximum Affordability

The ability to provide safe, habitable, comfortable housing for very low income residents within the target budget of $10,000 presents unique design and construction challenges. However, a number of preliminary conclusions have been inferred as being important concepts relative to the study of affordable housing. The term affordable housing can have many meanings and research is needed to define this explicitly. As it is most often used, affordable housing refers to an economic relationship between the price of housing, household income and current interest rates available from a lending institution. There is no direct relationship between architectural style, construction technology or user needs and the concept of affordability. For any home to be affordable, the home owner must balance the combination of housing needs and desires within the limits of an actual budget. There are many misconceptions that affordable housing must be defined as housing for those who cannot afford the free-market price. The concept of affordable housing must also include a component that recognizes the quality of the housing as an important element of the design and construction. In addition, responses to local climate impacts are necessary and are always part of a regional expression of architectural design. By …
Date: April 19, 1999
Creator: Aglan, H.; Gibbons, A.; McQueen, T. M.; Morris, C.; Raines, J. & Wendt, R. L.
Object Type: Article
System: The UNT Digital Library
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 86, Ed. 1 Tuesday, January 19, 1999 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 86, Ed. 1 Tuesday, January 19, 1999

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: January 19, 1999
Creator: Allam, Heather
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 109, Ed. 1 Friday, February 19, 1999 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 109, Ed. 1 Friday, February 19, 1999

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: February 19, 1999
Creator: Allam, Heather
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 143, Ed. 1 Monday, April 19, 1999 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 143, Ed. 1 Monday, April 19, 1999

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: April 19, 1999
Creator: Allam, Heather
Object Type: Newspaper
System: The Gateway to Oklahoma History
Context-Dependent Prognostics and Health Assessment: A Condition-Based Maintenance Approach That Supports Mission Compliance (open access)

Context-Dependent Prognostics and Health Assessment: A Condition-Based Maintenance Approach That Supports Mission Compliance

In today's manufacturing environment, plants, systems, and equipment are being asked to perform at levels not thought possible a decade ago. The intent is to improve process operations and equipment reliability, availability, and maintainability without costly upgrades. Of course these gains must be achieved without impacting operational performance. Downsizing is also taking its toll on operations. Loss of personnel, particularly those who represent the corporate history, is depleting US industries of their valuable experiential base which has been relied on so heavily in the past. These realizations are causing companies to rethink their condition-based maintenance policies by moving away from reacting to equipment problems to taking a proactive approach by anticipating needs based on market and customer requirements. This paper describes a different approach to condition-based maintenance-context-dependent prognostics and health assessment. This diagnostic capability is developed around a context-dependent model that provides a capability to anticipate impending failures and determine machine performance over a protracted period of time. This prognostic capability links operational requirements to an economic performance model. In this context, a system may provide 100% operability with less than 100% functionality. This paradigm is used to facilitate optimal logistic supply and support.
Date: April 19, 1999
Creator: Allgood, G. O. & Kercel, S. W.
Object Type: Article
System: The UNT Digital Library
Hybrid options for light-duty vehicles. (open access)

Hybrid options for light-duty vehicles.

Hybrid electric vehicles (HEVs) offer great promise in improving fuel economy. In this paper, we analyze why, how, and by how much vehicle hybridization can reduce energy consumption and improve fuel economy. Our analysis focuses on efficiency gains associated solely with vehicle hybridization. We do not consider such other measures as vehicle weight reduction or air- and tire-resistance reduction, because such measures would also benefit conventional technology vehicles. The analysis starts with understanding the energy inefficiencies of light-duty vehicles associated with different operation modes in US and Japanese urban and highway driving cycles, with the corresponding energy-saving potentials. The potential for fuel economy gains due to vehicle hybridization can be estimated almost exclusively on the basis of three elements: the reducibility of engine idling operation, the recoverability of braking energy losses, and the capability of improving engine load profiles to gain efficiency associated with specific HEV configurations and control strategies. Specifically, we evaluate the energy efficiencies and fuel economies of a baseline MY97 Corolla-like conventional vehicle (CV), a hypothetical Corolla-based minimal hybrid vehicle (MHV), and a MY98 Prius-like full hybrid vehicle (FHV). We then estimate energy benefits of both MHVs and FHVs over CVs on a performance-equivalent basis. We conclude …
Date: July 19, 1999
Creator: An, Feng; Stodolsky, Frank & Santini, Danilo
Object Type: Article
System: The UNT Digital Library
Irreversible Sorption of Contaminants During Ferrihydrite Transformation (open access)

Irreversible Sorption of Contaminants During Ferrihydrite Transformation

A better understanding of the fraction of contaminants irreversibly sorbed by minerals is necessary to effectively quantify bioavailability. Ferrihydrite, a poorly crystalline iron oxide, is a natural sink for sorbed contaminants. Contaminants may be sorbed/occluded as ferrihydrite precipitates in natural waters or as it ages and transforms to more crystalline iron oxides such as goethite or hematite. Laboratory studies indicate that Cd, Co, Cr, Cu, Ni, Np, Pb, Sr, U, and Zn are irreversibly sorbed to some extent during the aging and transformation of synthetic ferrihydrite. Barium, Ra and Sr are known to sorb on ferrihydrite in the pH range of 6 to 10 and sorb more strongly at pH values above its zero point of charge (pH> 8). We will review recent literature on metal retardation, including our laboratory and modeling investigation of Ba (as an analogue for Ra) and Sr adsorption/resorption, during ferrihydrite transformation to more crystalline iron oxides. Four ferrihydrite suspensions were aged at pH 12 and 50 °C with or without Ba in 0.01 M KN03 for 68 h or in 0.17 M KN03 for 3424 h. Two ferrihydrite suspensions were aged with and without Sr at pH 8 in 0.1 M KN03 at 70°C. Barium …
Date: May 19, 1999
Creator: Anderson, H. L.; Arthur, S. E.; Brady, P. V.; Cygan, R. T.; Nagy, K. L. & Westrich, H. R.
Object Type: Article
System: The UNT Digital Library
LCEs for Naval Reactor Benchmark Calculations (open access)

LCEs for Naval Reactor Benchmark Calculations

The purpose of this engineering calculation is to document the MCNP4B2LV evaluations of Laboratory Critical Experiments (LCEs) performed as part of the Disposal Criticality Analysis Methodology program. LCE evaluations documented in this report were performed for 22 different cases with varied design parameters. Some of these LCEs (10) are documented in existing references (Ref. 7.1 and 7.2), but were re-run for this calculation file using more neutron histories. The objective of this analysis is to quantify the MCNP4B2LV code system's ability to accurately calculate the effective neutron multiplication factor (k{sub eff}) for various critical configurations. These LCE evaluations support the development and validation of the neutronics methodology used for criticality analyses involving Naval reactor spent nuclear fuel in a geologic repository.
Date: July 19, 1999
Creator: Anderson, W.J.
Object Type: Report
System: The UNT Digital Library

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History

Joseph H. Williams Tallgrass Prairie Preserve

Photograph of a scene at the Joseph H. Williams Tallgrass Prairie Preserve.
Date: July 19, 1999
Creator: Argo, Jim
Object Type: Photograph
System: The Gateway to Oklahoma History