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Adsorption of radionuclides on minerals studies illustrating the effect of solid phase selectivity and of mechanisms controlling sorption processes

Description: Currently, extensive research is being done on the geochemistry of Yucca Mountain, Nevada. The purpose of this research is to determine whether this location would be suitable as a permanent high-level radioactive waste repository. Site characterization tests must prove that Yucca Mountains` geology will safely isolate radioactive waste from the environment for at least 10,000 years before approval is granted. In order for this to occur, it is necessary to study the sorptive properties of the host rock, and its selectivity in sorption of solutions containing multiple radionuclides. Validation of this must occur, because in the case of a catastrophic leak, the host rock must have properties that will retard the migration of radionuclides. Columnar experimental techniques were employed using goethite, (a hydrous iron oxide), beidellite (clay mineral), & {open_quotes}nonscents{close_quotes} (a zeolitized volcanic tuff) as sorbents. These sorbents were used to measure the isotherms of an identical binary solution (Ni-Sr) to illustrate the selectivity that occurs in different minerals. In beidellite, the sorption process was ideal, while for {open_quotes}nonscents{close_quotes} there was a strong preference for Sr{sup 2+}. The sorption process was modeled (Ni-Sr {open_quotes}Nonscents{close_quotes}) using ion exchange theory as the mechanism. In goethite, the sorption of Ni-Sr showed a complete preference for Ni{sup 2+} at a pH of 7. In various other systems for goethite. Co-Ni (pH=7) was ideal (no selectivity) where the ratios in the solid and solution phases were relatively equal. Conversely in the case of the Pb-Ni system, the Pb{sup 2+} ion predominated completely in the solidphase over Ni{sup 2+} at a pH of 5.5. Noting the strong effect of pH on the sorption process in goethite, the selectivity could not necessarily be credited to ion-exchange because of possible exclusion from charged sites at low pH values.
Date: February 1, 1996
Creator: Netus, B.
Partner: UNT Libraries Government Documents Department

Indenter geometry effects on the measurements of mechanical properties by nanoindentation with sharp indenters

Description: The measurement of mechanical properties by nanoindentation methods is most often conducted using indenters with the Berkovich geometry (a triangular pyramid) or with a sphere. These indenters provide a wealth of information, but there are certain circumstances in which it would be useful to make measurements with indenters of other geometries. We have recently explored how the measurement of hardness and elastic modulus can be achieved using sharp indenters other than the Berkovich. Systematic studies in several materials were conducted with a Vickers indenter, a conical indenter with a half-included tip angle of 70.3{degrees}, and the standard Berkovich indenter. All three indenters are geometrically similar and have nominally the same area-to-depth relationship, but there are distinct differences in the behavior of each. Here, we report on the application of these indenters in the measurement of hardness and elastic modulus by nanoindentation methods and some of the difficulties that occur.
Date: May 1, 1996
Creator: Tsui, T.Y.; Pharr, G.M. & Oliver, W.C.
Partner: UNT Libraries Government Documents Department

A study of the effect of nonrandom sampling on the estimation of exposure variability using exposure-time series from the OSHA IMIS health inspection database

Description: The objective of this study was to determine the effect of nonrandom sampling over time may have on the estimation of variability, namely the geometric standard deviation, using time series of personal exposure data.
Date: May 1, 1997
Creator: Martinez, L.T.
Partner: UNT Libraries Government Documents Department

Detector array design

Description: Neutron scattering facility at Oak-Ridge National is used to measure residual stresses in many different materials. Neutron beam from the reactor can be used to penetrate the inner atomic distances of metals which then can be diffracted to a detector to measure the strain. The strain data later can be converted to stresses. The facility currently uses only one detector to carry the measurement. By designing an array of detectors data can be obtained at a much faster rate and or having a much better and improved resolution. The purpose of this report is to show design of such array of detectors and their movements (rotation) for possible maximum data collection at a faster rate.
Date: February 1, 1996
Creator: Lari, S.
Partner: UNT Libraries Government Documents Department

Summaries of FY 1996 geosciences research

Description: The Geosciences Research Program is directed by the Department of Energy`s (DOE`s) Office of Energy Research (OER) through its Office of Basic Energy Sciences (OBES). Activities in the Geosciences Research Program are directed toward building the long-term fundamental knowledge base necessary to provide for energy technologies of the future. Future energy technologies and their individual roles in satisfying the nations energy needs cannot be easily predicted. It is clear, however, that these future energy technologies will involve consumption of energy and mineral resources and generation of technological wastes. The earth is a source for energy and mineral resources and is also the host for wastes generated by technological enterprise. Viable energy technologies for the future must contribute to a national energy enterprise that is efficient, economical, and environmentally sound. The Geosciences Research Program emphasizes research leading to fundamental knowledge of the processes that transport, modify, concentrate, and emplace (1) the energy and mineral resources of the earth and (2) the energy by-products of man.
Date: December 1, 1996
Partner: UNT Libraries Government Documents Department

Speciation of Fe in ambient aerosol and cloudwater

Description: Atmospheric iron (Fe) is thought to play an important role in cloudwater chemistry (e.g., S(IV) oxidation, oxidant production, etc.), and is also an important source of Fe to certain regions of the worlds oceans where Fe is believed to be a rate-limiting nutrient for primary productivity. This thesis focuses on understanding the chemistry, speciation and abundance of Fe in cloudwater and aerosol in the troposphere, through observations of Fe speciation in the cloudwater and aerosol samples collected over the continental United States and the Arabian Sea. Different chemical species of atmospheric Fe were measured in aerosol and cloudwater samples to help assess the role of Fe in cloudwater chemistry.
Date: August 15, 1996
Creator: Siefert, L.
Partner: UNT Libraries Government Documents Department

Followup calculations for the UVAR LEU conversion

Description: The UVAR reactor was successfully converted to LEU fuel in April 1994. Void coefficient measurements were made on the 4-by-4 fully-graphite-reflected LEU-1 core configuration, and an isothermal temperature coefficient measurement was made on the operational 4-by-5 partially-graphite-reflected LEU-2 core configuration. Both of these experiments have now been modeled in their critical configurations using the 3DBUM code. The LEU cores were also modeled using the Monte Carlo code MCNP in order to obtain a neutron/gamma source for BNCT filter design calculations. Advanced BNCT filters have been evaluated using both MCNP and the discrete ordinates code DORT. The results indicate that the UVAR would be an ideal source for the BNCT treatment of brain tumors.
Date: December 31, 1995
Creator: Rydin, R.A.; Hosticka, B. & Burns, T.
Partner: UNT Libraries Government Documents Department

Analysis of offsite dose calculation methodology for a nuclear power reactor

Description: This technical study reviews the methodology for calculating offsite dose estimates as described in the offsite dose calculation manual (ODCM) for Pennsylvania Power and Light - Susquehanna Steam Electric Station (SSES). An evaluation of the SSES ODCM dose assessment methodology indicates that it conforms with methodology accepted by the US Nuclear Regulatory Commission (NRC). Using 1993 SSES effluent data, dose estimates are calculated according to SSES ODCM methodology and compared to the dose estimates calculated according to SSES ODCM and the computer model used to produce the reported 1993 dose estimates. The 1993 SSES dose estimates are based on the axioms of Publication 2 of the International Commission of Radiological Protection (ICRP). SSES Dose estimates based on the axioms of ICRP Publication 26 and 30 reveal the total body estimates to be the most affected.
Date: December 31, 1995
Creator: Moser, D.M.
Partner: UNT Libraries Government Documents Department

Comparative evaluation of the US Environmental Protection Agency`s and the Oak Ridge Institute for Science and Education`s environmental survey and site assessment program field sampling procedures

Description: At the request of the U.S. Nuclear Regulatory Commission`s (NRC`s) Headquarters Office, the Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute for Science and Education (ORISE) compared the documented procedures that the U.S. Environmental Protection Agency (EPA) and ESSAP use for collecting environmental samples. The project objectives were to review both organizations` procedures applicable to collecting various sample matrices, compare the procedures for similarities and differences, and then to evaluate the reason for any identified procedural differences and their potential impact on ESSAP`s sample data quality. The procedures reviewed included those for sampling surface and subsurface soil, surface and groundwater, vegetation, air, and removable surface contamination. ESSAP obtained copies of relevant EPA documents and reviewed and prepared a tabulated summary of each applicable procedure. The methods for collecting and handling each type of sample were evaluated for differences, and where these were identified, the significance and effect of the differences on analytical quality were determined. The results of the comparison showed that, overall, the procedures and methods that EPA and ESSAP use for sample collection are very similar. The number of minor differences noted were the result of restrictions or procedures necessary to ensure sample integrity and prevent the introduction of interfering compounds when samples are to be analyzed for chemical parameters. For most radio nuclide analyses, these additional procedures are not necessary. Another item noted was EPA`s inclusion of steps that reduce the potential for sample cross-contamination by preparing (dressing) a location prior to collecting a sample or removing a portion of a sample prior to containerization.
Date: October 1, 1997
Creator: Vitkus, T.J.; Bright, T.L. & Roberts, S.A.
Partner: UNT Libraries Government Documents Department

Allergy arising from exposure to airborne contaminants in an insect rearing facility: Health effects and exposure control

Description: In agricultural crop improvement, yield under various stress conditions and limiting factors is assessed experimentally. Of the stresses on plants which affect yield are those due to insects. Ostrinia nubilalis, the European corn borer (corn borer) is a major pest in sweet and field corn in the U.S. There are many ways to fight crop pests such as the corn borer, including (1) application of chemical insecticides, (2) application of natural predators and, (3) improving crop resistance through plant genetics programs. Randomized field trials are used to determine the effectiveness of pest management programs. These trials frequently consist of randomly selected crop plots to which well-defined input regimes are instituted. For example, corn borers might be released onto crop plots in several densities at various stages of crop development, then sprayed with different levels of pesticide. These experiments are duplicated across regions and, in some cases across the country, to determine, in this instance for example, the best pesticide application rate for a given pest density and crop development stage. In order to release these pests onto crop plots, one must have an adequate supply of the insect pest. In winter months studies are carried out in the laboratory to examine chemical and natural pesticide effectiveness, as well as such things as the role of pheromones in moth behavior. The advantage in field trials is that yield data can be garnered directly. In this country, insects are raised for crop research primarily through the US Department of Agriculture, in cooperation with public Land Grant Universities and, by the private sector agricultural concerns - seed companies and others. This study quantifies the airborne allergen exposure of persons working in a Land Grant University entomology lab were allergy to European corn borer was suspected.
Date: June 1, 1994
Creator: Wolff, D.
Partner: UNT Libraries Government Documents Department

Spatio-temporal statistical models with applications to atmospheric processes

Description: This doctoral dissertation is presented as three self-contained papers. An introductory chapter considers traditional spatio-temporal statistical methods used in the atmospheric sciences from a statistical perspective. Although this section is primarily a review, many of the statistical issues considered have not been considered in the context of these methods and several open questions are posed. The first paper attempts to determine a means of characterizing the semiannual oscillation (SAO) spatial variation in the northern hemisphere extratropical height field. It was discovered that the midlatitude SAO in 500hPa geopotential height could be explained almost entirely as a result of spatial and temporal asymmetries in the annual variation of stationary eddies. It was concluded that the mechanism for the SAO in the northern hemisphere is a result of land-sea contrasts. The second paper examines the seasonal variability of mixed Rossby-gravity waves (MRGW) in lower stratospheric over the equatorial Pacific. Advanced cyclostationary time series techniques were used for analysis. It was found that there are significant twice-yearly peaks in MRGW activity. Analyses also suggested a convergence of horizontal momentum flux associated with these waves. In the third paper, a new spatio-temporal statistical model is proposed that attempts to consider the influence of both temporal and spatial variability. This method is mainly concerned with prediction in space and time, and provides a spatially descriptive and temporally dynamic model.
Date: December 31, 1996
Creator: Wikle, C.K.
Partner: UNT Libraries Government Documents Department

Determination of the feasibility of using open path FTIR to monitor levels of 3-methylfuran and 1-octen-3-ol for the purpose of detecting microbial contamination in indoor environments

Description: Studies have shown that the presence of microbial growth correlates with health complaints associated with sick building syndrome. Microbial growth may be found in damp places within a building, and may be dispersed to other areas if present in the HVAC system. Certain individuals may be especially sensitive to the presence of these microorganisms, and may experience adverse reactions at extremely low concentrations. Unfortunately, the source of the problem may not be discovered because many times the microbial growth is not visible. However, there are some volatile organic compounds that are given off by certain microorganisms which may be used to determine the presence of microbial contamination. 3-Methylfuran is an excellent indicator of growing fungi. It is produced by a majority of fungi, and can be used as an indicator of ongoing growth. 1-Octen-3-ol is also produced by a number of fungi, and has been used in the past as an indicator of such. These two compounds and many other volatiles given off by microorganisms have been termed microbial volatile organic compounds (MVOCs). Many of these compounds are commonly found in indoor air, and thus, may be present even when there is not microbial contamination.
Date: March 1, 1996
Creator: Olive, B.
Partner: UNT Libraries Government Documents Department

Proxy Records of the Indonesian Low and the El Ni{tilde n}o-Southern Oscillation (ENSO) from Stable Isotope Measurements of Indonesian Reef Corals

Description: The Earth`s largest atmospheric convective center is the Indonesian Low. It generates the Australasian monsoon, drives the zonal tropospheric Walker Circulation, and is implicated in the genesis of the El Nino-Southern Oscillation (ENSO). The long-term variability of the Indonesian Low is poorly characterized, yet such information is crucial for evaluating whether changes in the strength and frequency of ENSO events are a possible manifestation of global warming. Stable oxygen isotope ratios ({delta}{sup 18}O) in shallow-water reef coral skeletons track topical convective activity over hundreds of years because the input of isotopically-depleted rainwater dilutes seawater {delta}{sup 18}O. Corals also impose a temperature-dependent fractionation on {delta}{sup 18}O, but where annual rainfall is high and sea surface temperature (SST) variability is low the freshwater flux effect dominates.
Date: December 31, 1995
Creator: Moore, M.D.
Partner: UNT Libraries Government Documents Department

Validation of protection provided by one brand of filtering facepiece respirator

Description: A previous laboratory study of a widely used disposable dust / mist (D/M) respirator (3M{trademark}8710) utilized a challenge agent that had high penetration values for D/M filter media. Therefore, measured protection factors (PFs) reflected both filter and faceseal penetration, and would be lower than that expected for faceseal penetration only. The purpose of this study was to determine a PF for this brand of disposable D/M respirator using a challenge agent that has low filter penetration for this type of filter. Methodology involved qualitatively (QLFT) and quantitatively (QNFT) fit testing 15 males and 15 females while wearing the respirator. One QLFT was done per subject using the saccharin method. Three QNFTs were performed on each subject utilizing a 2.5 {mu}m mass median aerodynamic diameter (MMAD) monodisperse challenge aerosol. Measured PF`s were corrected for lung deposition of this size aerosol. The average fit for each subject was the arithmetic mean of the three PFs. The PFs were found to be approximately log-normally distributed, so logs of PFs were used in the statistical analysis. The exponent of the 95% lower tolerance level (LTL) of the fifth percentile of the log PFs was 50. This compares to an exponent of the 95% LTL of the fifth percentile of the log PFs of two determined in a previous study and to the American National Standards Institute (ANSI) Assigned Protection Factor (APF) of ten. No significant difference of average fit between males and females was found. The sensitivity of the saccharin QLFT was 42.9%, and specificity could not be evaluated.
Date: May 1, 1995
Creator: Peacock, J.R.
Partner: UNT Libraries Government Documents Department

Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

Description: Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 {mu}m in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.
Date: May 1, 1996
Creator: Pollack, B.R.
Partner: UNT Libraries Government Documents Department

1995 Annual epidemiologic surveillance report for Pantex Plant

Description: This report provides a summary of epidemiologic surveillance data collected from the Pantex Plant from January 1, 1995 through December 31,1995. The data were collected by a coordinator at Pantex and submitted to the Epidemiologic Surveillance Data Center,located at Oak Ridge Institute for Science and Education, where quality control procedures and data analyses were carried out. The data presented apply only to Pantex. The main sections of the report are the same as in previous years; the 1995 report provides additional information describing the work force by age and occupational groups.
Date: June 1, 1998
Partner: UNT Libraries Government Documents Department

Annual report for Hanford Site: Epidemiologic surveillance - 1994

Description: Epidemiologic surveillance at U.S. Department of Energy (DOE) facilities consists of regular and systematic collection, analysis, and interpretation of data on absences due to illness and injury in the work force. Its purpose is to provide an early warning system for health problems occurring among employees at participating sites. Data are collected by coordinators at each site and submitted to the Epidemiologic Surveillance Data Center, located at the Oak Ridge Institute for Science and Education, where quality control procedures and analyses are carried out. Rates of absences and rates of diagnoses associated with absences are analyzed by occupational and other relevant variables. They may be compared with the disease experience of different groups within the DOE work force and with populations that do not work for DOE to identify disease patterns or clusters that may be associated with work activities.This report provides the final summary for the Hanford Reservation.
Date: January 1, 1998
Partner: UNT Libraries Government Documents Department

Epidemiologic surveillance. Annual report for Idaho National Engineering Laboratory 1994

Description: Epidemiologic surveillance at DOE facilities consists of regular and systematic collection, analysis, and interpretation of data on absences due to illness and injury in the work force. Its purpose is to provide an early warning system for health problems occurring among employees at participating sites. In this annual report, the 1994 morbidity data for the Idaho National Engineering Laboratory are summarized. These analyses focus on absences of 5 or more consecutive workdays occurring among workers aged 17-85 years. They are arranged in five sets of tables that present: (1) the distribution of the labor force by occupational category and pay status; (2) the absences per person, diagnoses per absence, and diagnosis rates for the whole work force; (3) diagnosis rates by type of disease or injury; (4) diagnosis rates by occupational category; and (5) relative risks for specific types of disease or injury by occupational category.
Date: December 31, 1994
Partner: UNT Libraries Government Documents Department

Analysis of stray radiation produced by the advanced light source (1.9 GeV synchrotron radiation source) at Lawrence Berkeley Laboratory

Description: The yearly environmental dose equivalent likely to result at the closest site boundary from the Advanced Light Source was determined by generating multiple linear regressions. The independent variables comprised quantified accelerator operating parameters and measurements from synchronized, in-close (outside shielding prior to significant atmospheric scattering), state-of-the-art neutron remmeters and photon G-M tubes. Neutron regression models were more successful than photon models due to lower relative background radiation and redundant detectors at the site boundary. As expected, Storage Ring Beam Fill and Beam Crashes produced radiation at a higher rate than gradual Beam Decay; however, only the latter did not include zero in its 95% confidence interval. By summing for all three accelerator operating modes, a combined yearly DE of 4.3 mRem/yr with a 90% CI of (0.04-8.63) was obtained. These results fall below the DOE reporting level of 10 mRem/yr and suggest repeating the study with improved experimental conditions.
Date: December 31, 1995
Creator: Ajemian, R.C.
Partner: UNT Libraries Government Documents Department

MagRad: A code to optimize the operation of superconducting magnets in a radiation environment

Description: A powerful computational tool, called MagRad, has been developed which optimizes magnet design for operation in radiation fields. Specifically, MagRad has been used for the analysis and design modification of the cable-in-conduit conductors of the TF magnet systems in fusion reactor designs. Since the TF magnets must operate in a radiation environment which damages the material components of the conductor and degrades their performance, the optimization of conductor design must account not only for start-up magnet performance, but also shut-down performance. The degradation in performance consists primarily of three effects: reduced stability margin of the conductor; a transition out of the well-cooled operating regime; and an increased maximum quench temperature attained in the conductor. Full analysis of the magnet performance over the lifetime of the reactor includes: radiation damage to the conductor, stability, protection, steady state heat removal, shielding effectiveness, optimal annealing schedules, and finally costing of the magnet and reactor. Free variables include primary and secondary conductor geometric and compositional parameters, as well as fusion reactor parameters. A means of dealing with the radiation damage to the conductor, namely high temperature superconductor anneals, is proposed, examined, and demonstrated to be both technically feasible and cost effective. Additionally, two relevant reactor designs (ITER CDA and ARIES-II/IV) have been analyzed. Upon addition of pure copper strands to the cable, the ITER CDA TF magnet design was found to be marginally acceptable, although much room for both performance improvement and cost reduction exists. A cost reduction of 10-15% of the capital cost of the reactor can be achieved by adopting a suitable superconductor annealing schedule. In both of these reactor analyses, the performance predictive capability of MagRad and its associated costing techniques have been demonstrated.
Date: December 31, 1995
Creator: Yeaw, C.T.
Partner: UNT Libraries Government Documents Department

1995 annual epidemiologic surveillance report for Fernald Environmental Management Project

Description: The US Department of Energy's (DOE) commitment to assuring the health and safety of its workers includes the conduct of epidemiologic surveillance activities that provide an early warning system for health problems among workers. During the past several years, a number of DOE sites have participated in the Epidemiologic Surveillance Program. This program monitors illnesses and health conditions that result in an absence of five or more consecutive workdays, occupational injuries and illnesses, and disabilities and deaths among current workers. This report provides a summary of epidemiologic surveillance data collected from the Fernald Environmental Management Project (FEMP) from January 1, 1995 through December 31, 1995. The data were collected by a coordinator at FEMP and submitted to the Epidemiologic Surveillance Data Center, located at Oak Ridge Institute for Science and Education, where quality control procedures and data analyses were carried out.
Date: December 31, 1995
Partner: UNT Libraries Government Documents Department

Annual report for Brookhaven National Laboratory 1994 epidemiologic surveillance

Description: Epidemiologic surveillance at DOE facilities consists of regular and systematic collection, analysis, and interpretation of data on absences due to illness and injury in the work force. Its purpose is to provide an early warning system for health problems occurring among employees at participating sites. Data are collected by coordinators at each site and submitted to the Epidemiologic Surveillance Data Center, located at the Oak Ridge Institute for Science and Education, where quality control procedures and analyses are carried out. Rates of absences and rates of diagnoses associated with absences are analyzed by occupation and other relevant variables. They may be compared with the disease experience of different groups within the DOE work force and with populations that do not work for DOE to identify disease patterns or clusters that may be associated with work activities. In this annual report, the 1994 morbidity data for BNL are summarized. These analyses focus on absences of 5 or more consecutive workdays occurring among workers aged 16-80 years. They are arranged in five sets of tables that present: (1) the distribution of the labor force by occupational category and salary status; (2) the absences per person, diagnoses per absence, and diagnosis rates for the whole work force; (3) diagnosis rates by type of disease or injury; (4) diagnosis rates by occupational category; and (5) relative risks for specific types of disease or injury by occupational category.
Date: January 1, 1997
Partner: UNT Libraries Government Documents Department

Silica exposure to excavation workers during the excavation of a low level radiological waste pit and tritium disposal shafts

Description: This study evaluated the task-length average (TLA) respirable dust and respirable silica airborne concentrations to which construction workers excavating volcanic tuff at Los Alamos National Laboratory (LANL) were exposed. These workers were excavating a low level radiological waste disposal pit of final dimensions 720 feet long, 132 feet wide and 60 feet deep. The objectives of this study were as follows: (1) evaluate exposures; (2) determine if the type of machinery used affects the respirable dust concentration in the breathing zone of the worker; (3) evaluate the efficacy of wetting the pit to reduce the respirable dust exposure; and (4) determine if exposure increases with increasing depth of pit due to the walls of the pit blocking the cross wind ventilation.
Date: January 1, 1995
Creator: Wilson, K.M.
Partner: UNT Libraries Government Documents Department