141 research outputs found
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Addendum to the East Tennessee Technology Park Site-Wide Residual Contamination Remedial Investigation Work Plan Oak Ridge, Tennessee
The East Tennessee Technology Park Site-Wide Residual Contamination Remedial Investigation Work Plan (DOE 2004) describes the planned fieldwork to support the remedial investigation (RI) for residual contamination at the East Tennessee Technology Park (ETTP) not addressed in previous Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) decisions. This Addendum describes activities that will be conducted to gather additional information in Zone 1 of the ETTP for groundwater, surface water, and sediments. This Addendum has been developed from agreements reached in meetings held on June 23, 2010, August 25, 2010, October 13, 2010, November 13, 2010, December 1, 2010, and January 13, 2011, with representatives of the U. S. Department of Energy (DOE), U. S. Environmental Protection Agency (EPA), and Tennessee Department of Environment and Conservation (TDEC). Based on historical to recent groundwater data for ETTP and the previously completed Sitewide Remedial Investigation for the ETTP (DOE 2007a), the following six areas of concern have been identified that exhibit groundwater contamination downgradient of these areas above state of Tennessee and EPA drinking water maximum contaminant levels (MCLs): (1) K-720 Fly Ash Pile, (2) K-770 Scrap Yard, (3) Duct Island, (4) K-1085 Firehouse Burn/J.A. Jones Maintenance Area, (5) Contractor's Spoil Area (CSA), and (6) Former K-1070-A Burial Ground. The paper presents a brief summary of the history of the areas, the general conceptual models for the observed groundwater contamination, and the data gaps identified
Effectiveness of a multicomponent group-based treatment in patients with medically unexplained physical symptoms:A multisite naturalistic study
In-Drift Natural Convection and Condensation
The Yucca Mountain repository configuration consists of waste packages stored inside of underground tunnels, or drifts. The waste packages generate heat due to radioactive decay, and moisture flows into and out of the drifts in liquid and vapor form. Heat and mass transfer within the drifts, including interaction with the surrounding rock, are potentially important processes for the performance of the repository. The present report documents models for in-drift heat and mass transfer during the post-closure period. Pre-closure, or ventilated, conditions are documented in a separate report (BSC 2004 [DIRS 169862])
Czech version of the Outcome Rating Scale : Selected psychometric properties
Objectives. The Outcome Rating Scale (ORS) is an ultra-brief self-report scale designed to measure change during psychotherapy. The goal of this study was to test (a) the factor structure of the ORS, (b) the measurement invariance between a clinical and a non-clinical sample, between pre-therapy and post-therapy assessment (within the clinical sample), and between online and paper-and-pencil forms of administration (within the non-clinical sample), (c) concurrent validity with other outcome measures, and (d) sensitivity to therapeutic change. Sample and settings. N = 256 patients, N = 210 non-clinical respondents, and N = 89 students participated in the study. Patients responded to the ORS before and after psychotherapy. Statistical analysis. The factor structure and measurement invariance were tested using confirmatory factor analysis. Concurrent validity and test-retest reliability were assessed using correlational analysis. Sensitivity to change was assessed using the Reliable Change Index and pre-post effect size. Results. The unidimensional structure was supported. The best-fitting model was a partially tau-equivalent model with the first and the fourth itemsâ loadings fixed to the same value. While only metric invariance was demonstrated between the clinical and non-clinical samples, the ORS demonstrated scalar invariance between pre- and post-therapy assessment and strict invariance between the paper-and-pencil and online forms of administration. Internal consistency, as well as concurrent validity, were satisfactory. The sensitivity to the therapeutic change was adequate. Furthermore, internal consistency and sensitivity to change were increased if the score was computed as a weighted sum of items. Study limitation. The samples were not representative
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Peaking of world oil production: Impacts, mitigation, & risk management
The peaking of world oil production presents the U.S. and the world with an unprecedented risk management problem. As peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the economic, social, and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of peaking.... The purpose of this analysis was to identify the critical issues surrounding the occurrence and mitigation of world oil production peaking. We simplified many of the complexities in an effort to provide a transparent analysis. Nevertheless, our study is neither simple nor brief. We recognize that when oil prices escalate dramatically, there will be demand and economic impacts that will alter our simplified assumptions. Consideration of those feedbacks will be a daunting task but one that should be undertaken. Our aim in this study is to-- ⢠Summarize the difficulties of oil production forecasting; ⢠Identify the fundamentals that show why world oil production peaking is such a unique challenge; ⢠Show why mitigation will take a decade or more of intense effort; ⢠Examine the potential economic effects of oil peaking; ⢠Describe what might be accomplished under three example mitigation scenarios. ⢠Stimulate serious discussion of the problem, suggest more definitive studies, and engender interest in timely action to mitigate its impacts
Deliquescence of NaClâNaNO(3), KNO(3)âNaNO(3), and NaClâKNO(3 )salt mixtures from 90 to 120°C
We conducted reversed deliquescence experiments in saturated NaClâNaNO(3)âH(2)O, KNO(3)âNaNO(3)âH(2)O, and NaClâKNO(3)âH(2)O systems from 90 to 120°C as a function of relative humidity and solution composition. NaCl, NaNO(3), and KNO(3 )represent members of dust salt assemblages that are likely to deliquesce and form concentrated brines on high-level radioactive waste package surfaces in a repository environment at Yucca Mountain, NV. Discrepancy between model prediction and experiment can be as high as 8% for relative humidity and 50% for dissolved ion concentration. The discrepancy is attributed primarily to the use of 25°C models for ClâNO(3 )and KâNO(3 )ion interactions in the current Yucca Mountain Project high-temperature Pitzer model to describe the nonideal behavior of these highly concentrated solutions
Evaporative evolution of a NaâClâNO(3)âKâCaâSO(4)âMgâSi brine at 95°C: Experiments and modeling relevant to Yucca Mountain, Nevada
A synthetic Topopah Spring Tuff water representative of one type of pore water at Yucca Mountain, NV was evaporated at 95°C in a series of experiments to determine the geochemical controls for brines that may form on, and possibly impact upon the long-term integrity of waste containers and drip shields at the designated high-level, nuclear-waste repository. Solution chemistry, condensed vapor chemistry, and precipitate mineralogy were used to identify important chemical divides and to validate geochemical calculations of evaporating water chemistry using a high temperature Pitzer thermodynamic database. The water evolved toward a complex "sulfate type" brine that contained about 45 mol % Na, 40 mol % Cl, 9 mol % NO(3), 5 mol % K, and less than 1 mol % each of SO(4), Ca, Mg, âCO(2)(aq), F, and Si. All measured ions in the condensed vapor phase were below detection limits. The mineral precipitates identified were halite, anhydrite, bassanite, niter, and nitratine. Trends in the solution composition and identification of CaSO(4 )solids suggest that fluorite, carbonate, sulfate, and magnesium-silicate precipitation control the aqueous solution composition of sulfate type waters by removing fluoride, calcium, and magnesium during the early stages of evaporation. In most cases, the high temperature Pitzer database, used by EQ3/6 geochemical code, sufficiently predicts water composition and mineral precipitation during evaporation. Predicted solution compositions are generally within a factor of 2 of the experimental values. The model predicts that sepiolite, bassanite, amorphous silica, calcite, halite, and brucite are the solubility controlling mineral phases
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Progress toward a MEMS fabricated 100 GHz oscillator.
This report summarizes an LDRD effort which looked at the feasibility of building a MEMS (Micro-Electro-Mechanical Systems) fabricated 100 GHz micro vacuum tube. PIC Simulations proved to be a very useful tool in investigating various device designs. Scaling parameters were identified. This in turn allowed predictions of oscillator growth based on beam parameters, cavity geometry, and cavity loading. The electron beam source was identified as a critical element of the design. FEA's (Field Emission Arrays) were purchased to be built into the micro device. Laboratory testing of the FEA's was also performed which pointed out care and handling issues along with maximum current capabilities. Progress was made toward MEMS fabrication of the device. Techniques were developed and successfully employed to build up several of the subassemblies of the device. However, the lower wall fabrication proved to be difficult and a successful build was not completed. Alternative approaches to building this structure have been identified. Although these alternatives look like good solutions for building the device, it was not possible to complete a redesign and build during the timeframe of this effort
Climate Extremes Promote Fatal Co-Infections during Canine Distemper Epidemics in African Lions
Extreme climatic conditions may alter historic host-pathogen relationships and synchronize the temporal and spatial convergence of multiple infectious agents, triggering epidemics with far greater mortality than those due to single pathogens. Here we present the first data to clearly illustrate how climate extremes can promote a complex interplay between epidemic and endemic pathogens that are normally tolerated in isolation, but with co-infection, result in catastrophic mortality. A 1994 canine distemper virus (CDV) epidemic in Serengeti lions (Panthera leo) coincided with the death of a third of the population, and a second high-mortality CDV epidemic struck the nearby Ngorongoro Crater lion population in 2001. The extent of adult mortalities was unusual for CDV and prompted an investigation into contributing factors. Serological analyses indicated that at least five âsilentâ CDV epidemics swept through the same two lion populations between 1976 and 2006 without clinical signs or measurable mortality, indicating that CDV was not necessarily fatal. Clinical and pathology findings suggested that hemoparsitism was a major contributing factor during fatal epidemics. Using quantitative real-time PCR, we measured the magnitude of hemoparasite infections in these populations over 22 years and demonstrated significantly higher levels of Babesia during the 1994 and 2001 epidemics. Babesia levels correlated with mortalities and extent of CDV exposure within prides. The common event preceding the two high mortality CDV outbreaks was extreme drought conditions with wide-spread herbivore die-offs, most notably of Cape buffalo (Syncerus caffer). As a consequence of high tick numbers after the resumption of rains and heavy tick infestations of starving buffalo, the lions were infected by unusually high numbers of Babesia, infections that were magnified by the immunosuppressive effects of coincident CDV, leading to unprecedented mortality. Such mass mortality events may become increasingly common if climate extremes disrupt historic stable relationships between co-existing pathogens and their susceptible hosts
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