UNT Libraries Government Documents Department - 15 Matching Results

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Effects on Occupants of Enhanced Particle Filtration in a non-problem office environment: A Double-Blind Crossover Intervention Study

Description: Workers in indoor environments often complain of symptoms, such as eye and nose irritation, headache, and fatigue, which improve away from work. Exposures causing such complaints, sometimes referred to as sick building syndrome, generally have not been identified. Evidence suggests these worker symptoms are related to chemical, microbiological, physical, and psychosocial exposures not well characterized by current methods. Most research in this area has involved cross-sectional studies, which are limited in their abilities to show causal connections. Experimental studies have also been conducted which, by changing one factor at a time to isolate its effects, can demonstrate benefits of an environmental intervention even before exposures or mechanisms are understood. This study was prompted by evidence that particulate contaminants may be related to acute occupant symptoms and discomfort. The objective was to assess, with a double-blind, double crossover intervention design, whether improved removal of small airborne particles by enhanced central filtration would reduce symptoms and discomfort.
Date: June 15, 1998
Creator: Mendell, M.J.; Fisk, W.J.; Petersen, M.; Hines, C.J.; Faulkner, D.; Deddens, J.A. et al.

Impacts of cool cities on air quality: A preliminary modeling assessment for Nashville TN, Dallas TX and Atlanta GA

Description: Previous atmospheric modeling efforts that concentrated on the Los Angeles Basin suggested beneficial and significant air quality impacts from cool cities strategies. This paper discusses an extension of similar modeling efforts to three regions, Atlanta GA, Dallas - Ft. Worth TX, and Nashville TN, that experience smog and air quality problems. According to the older ozone air quality standard (120 ppb), these regions were classified as serious, moderate, and marginal, respectively, but may be out of compliance with respect to the newer, 80-ppb/8-hours standard. Results from this exploratory modeling work suggest a range of possible impacts on meteorological and air quality conditions. For example, peak ozone concentrations during each region's respective episode could be decreased by 1-6 ppb (conservative and optimistic scenarios, respectively) in Nashville, 5-15 ppb in Dallas - Fort Worth, and 5-12 ppb in Atlanta following implementation of cool cities. The reductions are generally smaller than those obtained from simulating the Los Angeles Basin but are still significant. In all regions, the simulations suggest, the net, domain-wide effects of cool cities are reductions in ozone mass and improvements in air quality. In Atlanta, Nashville, and Dallas, urban areas benefiting from reduced smog reach up to 8460, 7350, and 12870 km{sup 2} in area, respectively. Results presented in this paper should be taken as exploratory and preliminary. These will most likely change during a more comprehensive modeling study to be started soon with the support of the US Environmental Protection Agency. The main purpose of the present project was to obtain the initial data (emission inventories) for these regions, simulate meteorological conditions, and perform preliminary sensitivity analysis. In the future, additional regions will be simulated to assess the potential of cool cities in improving urban air quality.
Date: June 15, 1998
Creator: Taha, Haider

Injection System

Description: Felton Medical identified a market need for a handheld portable single shot needleless injection system. This market need was being driven by a global need to eliminate the hazards of medical needle disposal by providing an alternative injection method. Felton Medical brought to this partnership individuals experienced in the research, development, design, assembly, marketing, and servicing of precision animal health medical devices. AlliedSignal provided manufacturing understanding and a facility proficient in product development for small precision mechanical parts and assemblies.
Date: June 15, 1998
Creator: Thomas, J.E.

Isotopic Shifts in a Polaronic System

Description: The effect of isotopic substitution in a model polaronic system is presented. The authors use a three-site many body electron-phonon model which includes electronic correlations and electron-phonon interactions, showing the presence of polaron tunneling for intermediate and strong couplings. The isotopic substitution changes the dynamics of polaron tunneling. Additionally in the intermediate electron-phonon coupling regime, relevant for high-Tc superconductors, a change in the local structure is predicted. In this regime, the isotopic shift of phonon excitations is consistent with results of optical measurements of c-axis phonons in YBa{sub 2}Cu{sub 3}O{sub 7}.
Date: June 15, 1998
Creator: de Leon, J.M.; de Coss, R.; Rubia-Ponce, A.; Bishop, A.R. & Trugman, S.A.

Kinetic information from detonation front curvature

Description: The time constants for time-dependent modeling may be estimated from reaction zone lengths, which are obtained from two sources One is detonation front curvature, where the edge lag is close to being a direct measure The other is the Size Effect, where the detonation velocity decreases with decreasing radius as energy is lost to the cylinder edge A simple theory that interlocks the two effects is given A differential equation for energy flow in the front is used, the front is described by quadratic and sixth-power radius terms The quadratic curvature comes from a constant power source of energy moving sideways to the walls Near the walls, the this energy rises to the total energy of detonation and produces the sixth-power term The presence of defects acting on a short reaction zone can eliminate the quadratic part while leaving the wall portion of the cuvature A collection of TNT data shows that the reaction zone increases with both the radius and the void fraction
Date: June 15, 1998
Creator: Souers, P. C., LLNL

Light Machines Operator Performance Support System

Description: The objective of this project was to create a multimedia operator performance support system (OPSS) shell that would provide a framework for delivering appropriate information to the student/novice machine tool user just when needed and in the most appropriate form. In addition, the program was designed so that it could be expanded and further developed by Light Machines personnel. The expertise of AlliedSignal Federal Manufacturing and Technologies (ASFM and T) in the areas of performance support system design and multimedia creation was employed to create the most user-friendly graphical user interface (GUI) while providing access to key topical areas. Light Machines provided a subject matter expert from their technical services group in order to provide the needed information for structuring the OPSS shell. They also provided a Benchman VMC 4000 machine tool at the ASFM and T New Mexico location as well as specific instruction on the safe and effective use of that machine tool.
Date: June 15, 1998
Creator: Bohley, M.C.

Materials disposition plutonium acceptance specifications for the immobilization project

Description: The Department of Energy (DOE) has declared approximately 38.2 tonnes of weapons-grade plutonium to be excess to the needs of national security, 14.3 tonnes of fuel- and reactor-grade plutonium excess to DOE needs, and anticipates an additional 7 tonnes to be declared excess to national security needs. Of this 59.5 tonnes, DOE anticipates that ~ 7.5 tonnes will be dispositioned as spent fuel at the Geologic Repository and ~ 2 tonnes will be declared below the safeguards termination limit and be discarded as TRU waste at WIPP. The remaining 50 tonnes of excess plutonium exists in many forms and locations around the country, and is under the control of several DOE Offices. The Materials Disposition Program (MD) will be receiving materials packaged by these other Programs to disposition in a manor that meets the �spent fuel standard.� For disposition by immobilization, the planned facilities will have only limited capabilities to remove impurities prior to blending the plutonium feedstocks to prepare feed for the plutonium immobilization ceramic formation process, Technical specifications are described here that allow potential feedstocks to be categorized as either acceptable for transfer into the MD Immobilization Process, or unacceptable without additional processing prior to transfer to MD. Understanding the requirements should allow cost benefit analyses to be performed to determine if a specific material should be processed sufficiently shipment to WIPP. Preliminary analyses suggest that about 45 tonnes of this material have impurity concentrations much lower than the immobilization acceptance specifications. In addition, approximately another 3 tonnes can easily be blended with the higher purity feeds to meet the immobilization specifications. Another 1 tonne or so can be processed in the immobilization plutonium conversion area to yield materials that can be blended to provide acceptable feed for immobilization. The remaining 3 tonnes must be excluded in their ...
Date: June 15, 1998
Creator: Ebbinghaus, B.; Edmunds, T. A.; Gray, L.; Riley, D. C. & Vankonynenburg, R. A.

Neutron total and capture cross section measurements and resonance parameter analysis of tungsten from 0.01 eV to 200 eV

Description: Natural tungsten metal was measured using neutron time-of-flight spectroscopy at the Rensselaer Polytechnic Institute (RPI) Gaerttner Laboratory linear accelerator to determine the tungsten resonance parameters. Three separate measurements were performed: transmission, capture, and self-indication. Previous measurements did not employ all three experiment types and used less sophisticated methods. The current work improves on the published tungsten data base and reduces resonance parameter uncertainties.
Date: June 15, 1998
Creator: Werner, C.J.; Block, R.C.; Slovacek, R.E.; Overberg, M.E.; Moretti, B.E.; Burke, J.A. et al.

Spent nuclear fuel project recommended reaction rate constants for corrosion of N-Reactor fuel

Description: The US Department of Energy (DOE) established the Spent Nuclear Fuel Project (SNF Project) to address safety and environmental concerns associated with deteriorating spent nuclear fuel presently stored in the Hanford Site`s K Basins. The SNF Project has been tasked by the DOE with moving the spent N-Reactor fuel from wet storage to contained dry storage in order to reduce operating costs and environmental hazards. The chemical reactivity of the fuel must be understood at each process step and during long-term dry storage. Normally, the first step would be to measure the N-fuel reactivity before attempting thermal-hydraulic transfer calculations; however, because of the accelerated project schedule, the initial modeling was performed using literature values for uranium reactivity. These literature values were typically found for unirradiated, uncorroded metal. It was fully recognized from the beginning that irradiation and corrosion effects could cause N-fuel to exhibit quite different reactivities than those commonly found in the literature. Even for unirradiated, uncorroded uranium metal, many independent variables affect uranium metal reactivity resulting in a wide scatter of data. Despite this wide reactivity range, it is necessary to choose a defensible model and estimate the reactivity range of the N-fuel until actual reactivity can be established by characterization activities. McGillivray, Ritchie, and Condon developed data and/or models that apply for certain samples over limited temperature ranges and/or reaction conditions (McGillivray 1994, Ritchie 1981 and 1986, and Condon 1983). These models are based upon small data sets and have relatively large correlation coefficients.
Date: June 15, 1998
Creator: Cooper, T.D.