Radioactive supernate, salt, and/or sludge wastes (i.e., high level wastes) are confined in 49 underground storage tanks at the Savannah River Site (SRS). The waste is transported between tanks within and between the F and H area tank farms and other facilities on site via underground and a limited number of aboveground transfer lines. The Department of Energy - Savannah River Operations Office (DOE-SR) performed a comprehensive assessment of the structural integrity program for the Tank Farm waste transfer system at the SRS. This document addresses the following issues raised during the DOE assessment: (1) Inspections of failed or replaced transfer lines indicated that the wall thickness of some core and jacket piping is less than nominal; (2) No corrosion allowance is utilized in the transfer line structural qualification calculations. No basis for neglecting corrosion was provided in the calculations; (3) Wall loss due to erosion is not addressed in the transfer line structural qualification calculations; and (4) No basis is provided for neglecting intergranular stress corrosion cracking in the transfer line structural qualification calculations. The common theme in most of these issues is the need to assess the potential for occurrence of material degradation of the transfer line piping. …

Multianalyte bio(chemical) sensors are extensively researched for monitoring analytes in complex systems, such as blood serum. As a step towards developing such multianalyte sensors, we studied a novel, structurally integrated, organic light emitting device (OLED)-based sensing platform for detection of lactate. Lactate biosensors have attracted numerous research efforts, due to their wide applications in clinical diagnosis, athletic training and food industry. The OLED-based sensor is based on monitoring the oxidation reaction of lactate, which is catalyzed by the lactate oxidase (LOX) enzyme. The sensing component is based on an oxygen-sensitive dye, Platinum octaethyl porphyrin (PtOEP), whose photoluminescence (PL) lifetime {tau} decreases as the oxygen level increases. The PtOEP dye was embedded in a thin film polystyrene (PS) matrix; the LOX was dissolved in solution or immobilized in a sol-gel matrix. {tau} was measured as a function of the lactate concentration; as the lactate concentration increases, {tau} increases due to increased oxygen consumption. The sensors performance is discussed in terms of the detection sensitivity, dynamic range, and response time. A response time of {approx}32 sec was achieved when the LOX was dissolved in solution and kept in a closed cell. Steps towards development of a multianalyte sensor array using an array …

In this paper, we investigated the effects of substrate creep on the fatigue behavior of a model dental multilayer structure, in which a top glass layer was bonded to a polycarbonate substrate through a dental adhesive. The top glass layers were ground using 120 grit or 600 grit sand papers before bonding to create different sub-surface crack sizes and morphologies. The multilayer structures were tested under cyclic Hertzian contact loading to study crack growth and obtain fatigue life curves. The experiment results showed that the fatigue lives of the multilayer structures were impaired by increasing crack sizes in the sub-surfaces. They were also significantly reduced by the substrate creep when tested at relatively low load levels i.e. P{sub m} < 60 N (Pm is the maximum magnitude of cyclic load). But at relatively high load levels i.e. P{sub m} > 65 N, slow crack growth (SCG) was the major failure mechanisms. A modeling study was then carried out to explore the possible failure mechanisms over a range of load levels. It is found that fatigue life at relatively low load levels can be better estimated by considering the substrate creep effect (SCE).

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Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic …

Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A mixture of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. The mixture is single phase for higher salinity or calcium concentrations than that for either surfactant used alone. This makes it possible to inject the surfactant slug with polymer close to optimal conditions and yet be single phase. A formulation has been designed for a particular field application. It uses partially hydrolyzed polyacrylamide for mobility control. The addition of an alkali such as sodium carbonate makes possible in situ generation of naphthenic soap and significant reduction of synthetic surfactant adsorption. The design of the process to maximize the region of ultra-low IFT takes advantage of the observation that the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Even for a fixed ratio of soap to surfactant, the range of salinity for low IFT was wider than that reported for surfactant systems …

The National Spherical Torus Experiment (NSTX) routinely studies overdense plasmas with ne of (1–5) X 1019 m-3 and total magnetic field of <0.6 T, so that the first several electron cyclotron harmonics are overdense. The electrostatic electron Bernstein wave (EBW) can propagate in overdense plasmas, exhibits strong absorption, and is thermally emitted at electron cyclotron harmonics. These properties allow thermal EBW emission to be used for local Te measurement. A significant upgrade to the previous NSTX EBW emission diagnostic to measure thermal EBW emission via the oblique B-X-O mode conversion process has been completed. The new EBW diagnostic consists of two remotely steerable, quad-ridged horn antennas, each of which is coupled to a dual channel radiometer. Fundamental (8–18 GHz) and second and third harmonic (18–40 GHz) thermal EBW emission and polarization measurements can be obtained simultaneously.

The objective of this research project is two-fold. First, to fundamentally understand friction and relaxation dynamics of polymer chains near surfaces; and second, to develop novel self-lubricated substrates suitable for MEMS devices. During the three-year performance period of this study the PI and his students have shown using theory and experiments that systematic introduction of disorder into tethered lubricant coatings (e.g. by using self-assembled monolayer (SAM) mixtures or SAMs with nonlinear, branched architectures) can be used to significantly reduce the friction coefficient of a surface. They have also developed a simple procedure based on dielectric spectroscopy for quantifying the effect of surface disorder on molecular relaxation in lubricant coatings. Details of research accomplishments in each area of the project are described in the body of the report.

To address the DOE need for the storage and handling of terabyte of nuclear physics data, Physical Optics Corporation (POC) developed a new multi-terabit, 90° recording geometry 3D holographic archival optical memory storage and search system. In contrast to state-of-the-art memory approaches, 3DHAM handles the data through highly parallel optical processing in conjunction with highly redundant hologram multiplexing. The 3DHAM system advantages also stem from its unique 3D volume-recording medium, which theoretically has a significantly greater data density than diskbased systems.

Eddy current nondestructive evaluation (NDE) is usually carried out by exciting a time harmonic field using an inductive probe. However, a viable alternative is to use transient eddy current NDE in which a current pulse in a driver coil produces a transient .eld in a conductor that decays at a rate dependent on the conductivity and the permeability of the material and the coil configuration. By using transient eddy current, it is possible to estimate the properties of the conductive medium and to locate and size potential .aws from the measured probe response. The fundamental study described in this dissertation seeks to establish a theoretical understanding of the transient eddy current NDE. Compared with the Fourier transform method, the derived analytical formulations are more convenient when the transient eddy current response within a narrow time range is evaluated. The theoretical analysis provides a valuable tool to study the effect of layer thickness, location of defect, crack opening as well as the optimization of probe design. Analytical expressions have been developed to evaluate the transient response due to eddy currents in a conductive plate based on two asymptotic series. One series converges rapidly for a short time regime and the other …

This work considers the problem of accurately representing the temperature dependence of neutron cross-section data in neutron transport problems when there are many nuclides and when the temperature distributions vary significantly with both space and time. An approach involving interpolation between nuclear data libraries at various reference temperatures is investigated. Reference nuclear data libraries are obtained by Doppler broadening cross sections to the desired temperatures using the NJOY code system. Several interpolation schemes over various temperature intervals are studied. Interpolated values at intermediate temperatures are compared to NJOY Doppler broadened results for the same temperature. Differences relative to the Doppler broadened results are calculated in order to judge the suitability of the interpolation scheme and temperature interval. The total, elastic scattering, capture, and fission (if applicable) reactions for {sup 238}U, {sup 235}U, natural Zr, {sup 16}O, {sup 10}B and {sup 1}H are considered in this study, over a temperature range of 294 K to 811 K ({approx}70 F to {approx}1000 F). The nuclides and temperature range are selected to best represent typical light water reactor calculations. This work covers only the free-atom cross section and does not explore the many nuances of temperature treatment of nuclear data in the thermal …

Superconducting Gamma-ray detectors offer an order of magnitude higher energy resolution than conventional high-purity germanium detectors. This can significantly increase the precision of non-destructive isotope analysis for nuclear samples where line overlap affects the errors of the measurement. We have developed Gamma-detectors based on superconducting molybdenum-copper sensors and bulk tin absorbers for nuclear science and national security applications. They have, depending on design, an energy resolution between {approx}50 and {approx}150 eV FWHM at {approx}100 keV. Here we apply this detector technology to the measurement of uranium isotope ratios, and discuss the trade-offs between energy resolution and quantum efficiency involved in detector design.

The Urban Dispersion Program is a multi-year project, funded by the U.S. Department of Homeland Security, to better understand the flow and dispersion of airborne contaminants through and around the deep street canyons of New York City. The first tracer and meteorological field study was a limited study conducted during March 2005 near the Madison Square Garden in midtown Manhattan. Six safe, inert, gaseous perfluorocarbon tracers were released simultaneously at five street-level locations during two experimental days. In addition to collecting tracer data, meteorological data were also collected. Brookhaven National Laboratory conducted the bulk of the tracer and meteorological field efforts with Pacific Northwest National Laboratory and Stevens Institute of Technology assisting by measuring the vertical profile of winds. The Environmental Protection Agency worked with Brookhaven National Laboratory in accomplishing the personal exposure component of the study. This report presents some results from this analysis. In general, different release locations showed vastly different plume footprints for tracer materials, and the situation was made very complex with upwind and/or crosswind transport of tracer near street-level for the different release locations. Overall wind speeds and directions upwind and over the city were generally constant throughout each of the two experimental periods.

Atomic scale surface structure plays an important roleindescribing many properties of materials, especially in the case ofnanomaterials. One of the most effective techniques for surface structuredetermination is low-energy electron diffraction (LEED), which can beused in conjunction with optimization to fit simulated LEED intensitiesto experimental data. This optimization problem has a number ofcharacteristics that make it challenging: it has many local minima, theoptimization variables can be either continuous or categorical, theobjective function can be discontinuous, there are no exact analyticderivatives (and no derivatives at all for categorical variables), andfunction evaluations are expensive. In this study, we show how to apply aparticular class of optimization methods known as pattern search methodsto address these challenges. These methods donot explicitly usederivatives, and are particularly appropriate when categorical variablesare present, an important feature that has not been addressed in previousLEED studies. We have found that pattern search methods can produceexcellent results, compared to previously used methods, both in terms ofperformance and locating optimal results.

Under contract with the Nuclear Regulatory Commission (NRC), staff from Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratory (SNL)-Albuquerque reviewed the evacuation time estimate (ETE) analysis dated April 2006 prepared by IEM for the Vogtle Electric Generating Plant (VEGP). The ETE analysis was reviewed for consistency with federal regulations using the NRC guidelines in Review Standard (RS)-002, Supplement 2 and Appendix 4 to NUREG-0654, and NUREG/CR-4831. Additional sources of information referenced in the analysis and used in the review included NUREG/CR-6863 and NUREG/CR-6864. The PNNL report includes general comments, data needs or clarifications, and requests for additional information (RAI) resulting from review of the ETE analysis.

Metal oxide nanocrystals offer significant potential for use as catalysts or catalyst supports due to their high surface areas and unique chemical properties that result from the high number of exposed corners and edges. However, little is known about the catalytic activity of these materials, especially as oxidation catalysts. This research focused on the preparation, characterization and use of vanadium-containing nanocrystals as selective oxidation catalysts. Three vanadium-containing nanocrystals were prepared using a modified sol-gel procedure: V/MgO, V/SiO2, and vanadium phosphate (VPO). These represent active oxidation catalysts for a number of industrially relevant reactions. The catalysts were characterized by x-ray diffraction and Raman, UV-VIS, infrared and x-ray absorption spectroscopies with the goal of determining the primary structural and chemical differences between nanocrystals and microcrystals. The catalytic activity of these catalysts was also studied in oxidative dehydrogenation of butane and methanol oxidation to formaldehyde. V/MgO nanocrystals were investigated for activity in oxidative dehydrogenation of butane and compared to conventional V/MgO catalysts. Characterization of V/MgO catalysts using Raman spectroscopy and x-ray absorption spectroscopy showed that both types of catalysts contained magnesium orthovanadate at vanadium loadings below 15 weight%, but above that loading, magnesium pyrovanadate may have been present. In general, MgO nanocrystals had …