In experiments conducted on the RITS-6 accelerator, the SMP diode exhibits sig- ni cant shot-to-shot variability. Speci cally, for identical hardware operated at the same voltage, some shots exhibit a catastrophic drop in diode impedance. A study is underway to identify sources of shot-to-shot variations which correlate with diode impedance collapse. To remove knob emission as a source, only data from a shot series conducted with a 4.5-MV peak voltage are considered. The scope of this report is limited to sources of variability which occur away from the diode, such as power ow emission and trajectory changes, variations in pulsed power, dustbin and transmission line alignment, and di erent knob shapes. We nd no changes in the transmission line hardware, alignment, or hardware preparation methods which correlate with impedance collapse. However, in classifying good versus poor shots, we nd that there is not a continuous spectrum of diode impedance behavior but that the good and poor shots can be grouped into two distinct impedance pro les. This result forms the basis of a follow-on study focusing on the variability resulting from diode physics. 3
Distributed energy resources (DER) such as photovoltaic (PV) systems, when deployed in a large scale, are capable of influencing significantly the operation of power systems. Looking to the future, stakeholders are working on standards to make it possible to manage the potentially complex interactions between DER and the power system. In 2009, the Electric Power Research Institute (EPRI), Sandia National Laboratories (SNL) with the U.S. Department of Energy (DOE), and the Solar Electric Power Association (SEPA) initiated a large industry collaborative to identify and standardize definitions for a set of DER grid support functions. While the initial effort concentrated on grid-tied PV inverters and energy storage systems, the concepts have applicability to all DER. A partial product of this on-going effort is a reference definitions document (IEC TR 61850-90-7, Object models for power converters in distributed energy resources (DER) systems) that has become a basis for expansion of related International Electrotechnical Commission (IEC) standards, and is supported by US National Institute of Standards and Technology (NIST) Smart Grid Interoperability Panel (SGIP). Some industry-led organizations advancing communications protocols have also embraced this work. As standards continue to evolve, it is necessary to develop test protocols to independently verify that the inverters are properly executing the advanced functions. Interoperability is assured by establishing common definitions for the functions and a method to test compliance with operational requirements. This document describes test protocols developed by SNL to evaluate the electrical performance and operational capabilities of PV inverters and energy storage, as described in IEC TR 61850-90-7. While many of these functions are not now required by existing grid codes or may not be widely available commercially, the industry is rapidly moving in that direction. Interoperability issues are already apparent as some of these inverter capabilities are being incorporated in large demonstration and commercial projects. The test protocols are intended to be used to verify acceptable performance of inverters within the standard framework described in IEC TR 61850-90-7. These test protocols, as they are refined and validated over time, can become precursors for future certification test procedures for DER advanced grid support functions.
Sandia National Laboratories has created a test protocol for IEC TR 61850-90-7 advanced distributed energy resource (DER) functions, titled "Test Protocols for Advanced Inverter Interoperability Functions," often referred to as the Sandia Test Protocols. This document is currently in draft form, but has been shared with stakeholders around the world with the ultimate goal of collaborating to create a consensus set of test protocols which can be then incorporated into an International Electrotechnical Commission (IEC) and/or Underwriters Laboratories (UL) certification standard. The protocols are designed to ensure functional interoperability of DER (primarily photovoltaic (PV) inverters and energy storage systems) as specified by the IEC technical report through communication and electrical tests. In this report, Sandia exercises the electrical characterization portion of the test protocols for four functions: constant power factor (INV3), volt-var (VV11), frequency-watt (FW21), and Low and High Voltage Ride Through (L/HVRT). The goal of the tests reported here was not to characterize the performance of the equipment under test (EUT), but rather to (a) exercise the draft Sandia Test Protocols in order to identify any revisions needed in test procedures, conditions, or equipment and (b) gain experience with state-of-the-art DER equipment to determine if the tests put unrealistic or overly aggressive requirements on EUT operation. In performing the work according to the current versions of the protocols, Sandia was able to identify weaknesses in the current versions and suggest improvements to the test protocols.
Distributed energy resources (DER) such as photovoltaic (PV) systems, when deployed in a large scale, are capable of influencing significantly the operation of power systems. Looking to the future, stakeholders are working on standards to make it possible to manage the potentially complex interactions between DER and the power system. In 2009, the Electric Power Research Institute (EPRI), Sandia National Laboratories (SNL) with the U.S. Department of Energy (DOE), and the Solar Electric Power Association (SEPA) initiated a large industry collaborative to identify and standardize definitions for a set of DER grid support functions. While the initial effort concentrated on grid-tied PV inverters and energy storage systems, the concepts have applicability to all DER. A partial product of this on-going effort is a reference definitions document (IEC TR 61850-90-7, Object models for power converters in distributed energy resources (DER) systems) that has become a basis for expansion of related International Electrotechnical Commission (IEC) standards, and is supported by US National Institute of Standards and Technology (NIST) Smart Grid Interoperability Panel (SGIP). Some industry-led organizations advancing communications protocols have also embraced this work. As standards continue to evolve, it is necessary to develop test protocols to independently verify that the inverters are properly executing the advanced functions. Interoperability is assured by establishing common definitions for the functions and a method to test compliance with operational requirements. This document describes test protocols developed by SNL to evaluate the electrical performance and operational capabilities of PV inverters and energy storage, as described in IEC TR 61850-90-7. While many of these functions are not currently required by existing grid codes or may not be widely available commercially, the industry is rapidly moving in that direction. Interoperability issues are already apparent as some of these inverter capabilities are being incorporated in large demonstration and commercial projects. The test protocols are intended to be used to verify acceptable performance of inverters within the standard framework described in IEC TR 61850-90-7. These test protocols, as they are refined and validated over time, can become precursors for future certification test procedures for DER advanced grid support functions.
The performance of an Inverse Synthetic Aperture Radar (ISAR) system depends on a variety of factors, many which are interdependent in some manner. In this report we specifically examine ISAR as applied to maritime targets (e.g. ships). It is often difficult to get your arms around the problem of ascertaining achievable performance limits, and yet those limits exist and are dictated by physics. This report identifies and explores those limits, and how they depend on hardware system parameters and environmental conditions. Ultimately, this leads to a characterization of parameters that offer optimum performance for the overall ISAR system. While the information herein is not new to the literature, its collection into a single report hopes to offer some value in reducing the seek time.
Data, a brief description of key boundary conditions, and results of Sandia National Laboratories’ ongoing MELCOR analysis of the Fukushima Unit 2 accident are given for the reactor core isolation cooling (RCIC) system. Important assumptions and related boundary conditions in the current analysis additional to or different than what was assumed/imposed in the work of SAND2012-6173 are identified. This work is for the U.S. Department of Energy’s Nuclear Energy University Programs fiscal year 2014 Reactor Safety Technologies Research and Development Program RC-7: RCIC Performance under Severe Accident Conditions.
The purpose of this effort is to explore where the availability of water could be a limiting factor in the siting of new electric power generation. To support this analysis, water availability is mapped at the county level for the conterminous United States (3109 counties). Five water sources are individually considered, including unappropriated surface water, unappropriated groundwater, appropriated water (western U.S. only), municipal wastewater and brackish groundwater. Also mapped is projected growth in non-thermoelectric consumptive water demand to 2035. Finally, the water availability metrics are accompanied by estimated costs associated with utilizing that particular supply of water. Ultimately these data sets are being developed for use in the National Renewable Energy Laboratories' (NREL) Regional Energy Deployment System (ReEDS) model, designed to investigate the likely deployment of new energy installations in the U.S., subject to a number of constraints, particularly water.
We have developed a MEMS based thin (<100 μm), temperature stable (< 1 parts-per-billion per degree Celsius (ppb/°C)), low power (<10 mW), frequency reference. Traditional high stability oscillators are based on quartz crystals. While a mature technology, the large size of quartz crystals presents important mission barriers including reducing oscillator thickness below 400 μm, and low power temperature stabilization (ovenizing). The small volume microresonators are 2 μm thick compared to 100’s of microns for quartz, and provide acoustic/thermal isolation when suspended above the substrate by narrow beams. This isolation enables a new paradigm for ovenizing oscillators at revolutionary low power levels <10 mW as compared to >300 mW for oven controlled quartz oscillators (OCXO). The oven controlled MEMS oscillator (OCMO) takes advantage of high thermal isolation and CMOS integration to ovenize the entire oscillator (AlN resonator and CMOS) on a suspended platform. This enables orders of magnitude reductions in size and power as compared with today's OCXO technology.
Dose rate calculations for a receptor well in a generic reference aquifer are highly dependent on the mixing that occurs in the aquifer and well. This paper presents analytical expressions for determining radionuclide concentrations at the receptor well in a generic aquifer by calculating the overall dilution that occurs in the system and factoring in the effects of travel time and radionuclide decay. Expressions are derived for four types of sources: vertical borehole (advective), point source (advective), point source (diffusive), and broad area diffusion. Example applications of each solution are presented and compared.
Research on deep borehole disposal of high-level radioactive waste has indicated that the deep borehole disposal concept is a viable potential alternative to a mined repository system. Previous modeling indicates that thermally induced fluid flow associated with heat from the waste has the greatest potential for the upward transport of dissolved radionuclides. An updated thermal-hydrologic model of a deep borehole disposal system is constructed using a recently developed reference design, incorporating a more realistic heterogeneous representation of the hydrogeological system with depth-varying permeability and thermal conductivity, coupled stratification of salinity and fluid density, and arrays of up to 81 disposal boreholes. Results show that peak temperatures near the borehole occur within 20 years of disposal, with an extended period of elevated temperatures beyond 10, 000 years and a second, lower peak in temperature near the center of larger borehole arrays. Simulated vertical upward groundwater flux in the borehole and disturbed rock zone occurs in the waste disposal zone and overlying seal zone at greatest magnitude for about 100 years, but persists for an extended period of time. The persistence of simulated vertical groundwater flow beyond 1, 000 years increases with the number of disposal boreholes in the array. This persistence in flow may have important implications for the maximum number of disposal boreholes that could be safely emplaced at a single site.
Within the Used Fuel Disposition Campaign (UFDC) of the United States Department of Energy Office of Nuclear Energy (DOE-NE), we have investigated used fuel (UF) degradation and radionuclide mobilization (UFD&RM) and implemented/produced a set of models encompassing radiolytic processes, UF matrix degradation, instant release fractions (IRF) of key radionuclides, and first-principles atomistic models for UO2 and its potential corrosion products. The goals of this collaborative effort (among three different national laboratories: Argonne National Laboratory [ANL]; Pacific Northwest National Laboratory [PNNLJ; and Sandia National Laboratories [SNL]) are to enhance the understanding of UF degradation processes and the technical bases for safety analyses in a range of generic disposal environments. In addition to these modeling efforts, integrated experimental studies are being conducted at both ANL and PNNL to evaluate and validate (and ultimately expand) process models for radiolytic phenomena and UF matrix degradation in various geologic disposal conditions. Integration and coupling of these process models into a generic performance assessment model (GPAM) is one focus of SNL efforts within the generic analyses of the Engineered Barrier System (EBS) for various repository environments. As discussed below, the present work has produced a set of models for implementation into the GPAM as an initial step towards an enhanced coupled model of source-term processes.
Once sufficiently cool, spent nuclear fuel is stored in dry storage cask systems, most commonly consisting of welded stainless steel containers enclosed in ventilated concrete or steel overpacks. As the United States does not currently have a viable disposal pathway for SNF, these containers may be required to perform their waste isolation function for many decades beyond their original design criteria. Failure by stress corrosion cracking due to deliquescence of deposited salt aerosols is a major concern. Parameters controlling deliquescence include the temperature and RH at the waste package surface, and the composition of deposited salts. The timing and duration of deliquescence under in situ conditions is poorly defined, because of uncertainties in thermal history, the large variability in temperatures over the storage container surface, and uncertainties in the composition of deposited salts. Storage installations in near-marine environments are of greatest concern because of exposure to significant quantities of chloride-rich sea salt aerosols. Published stainless steel corrosion studies with sea salt and sea salt components suggest that conditions conducive to localized corrosion initiation and propagation may exist on the surface of SNF storage containers in such environments at some point in their extended service life, and furthermore, that stress corrosion cracking may occur over a broad range of potentially relevant conditions. However, the studies were carried out with heavy salt loads and limited gas flow, which may limit the beneficial effects of brine/atmosphere exchange (e.g., acid degassing, CO2 exchange, degassing and thermal decomposition of ammonium phases). Gas exchange with the atmosphere will modify brine pH and chloride content, and will modify the deliquescent salt assemblage through precipitation of Ca and Mg carbonates, potentially limiting brine volumes or resulting in dryout. Nitrate-rich inland salt aerosols are considered less corrosive, but may have higher levels of potentially reactive pollutants. Moreover, the compositions of inland salt deposits on hot storage containers may have greater uncertainty, as ammonium- and nitrate-rich salt assemblages are subject to thermal decomposition and potential reactions with organics. For both inland and near-marine sites, little information is available on the dust/salt deposition rates, or the quantity of salt present on existing storage container surfaces. A sampling program for in situ dust deposits on current storage containers will provide critical compositional data for new stress corrosion cracking studies, and will allow evaluation of the applicability of existing studies of stainless steel stress corrosion cracking under conditions of dust deliquescence.
A hybrid Potts-phase field model to simulate hydride nucleation and growth in Zr-claddings is presented. It simulates nucleation of hydrides at grain boundaries and their subsequent growth by diffusion of hydrogen to precipitates. The model is demonstrated by simulating hydride precipitation in two different cladding of identical composition, but different grain structures. The claddings are supersaturated with hydrogen as would be expected after drying at the beginning of dry storage. The resulting hydrides have distinct morphologies with implications for the mechanical behavior and fracture strength of the claddings after dry storage.
This paper reports the results of a series of multiyear experiments investigating the anoxic corrosion of steel and Pb alloys in NaCl±Mg brines under WIPP-relevant conditions. The objectives of this work are to determine: (a) the extent to which steel and Pb consume CO2 via the formation of carbonates or other phases, potentially supporting MgO in CO 2 sequestration; and (b) corrosion rates that can then be used to calculate hydrogen gas generation rates for use in WIPP performance assessment calculations.
Significant laboratory and in situ testing has been conducted by both the United States and Germany on salt disposal of heat-generating radioactive waste. Coupled simulation capabilities recently developed in other fields are now being applied to repository design and performance confirmation. New efforts are underway to benchmark this latest generation of numerical models, requiring quality validation datasets. Datasets associated with historic high-level waste (HL W) field experiments at the Waste Isolation Pilot Plant in New Mexico, Avery Island in Louisiana, Asse II in Germany, and Project Salt Vault in Kansas should be considered before constructing new experiments. We constructed an online bibliographic database using the web reference database (Refbase) distribution to contain references to reports, and conference papers, along with associated electronic copies of reports and associated data. The database was populated using publically available Department of Energy sources and project-specific archives scanned for this project. The browser-based database facilitated an extensive collaborative review of experiments in geologic salt-primarily concerning heated salt that may be applicable to modern code validation efforts. We summarize historic in situ tests conducted in geologic salt, focusing on heated salt creep, heated brine migration, and crushed salt reconsolidation. We propose several candidate thermal, mechanical, and hydrological validation datasets for salt behavior under repository conditions.
The use of integrated probabilistic risk assessment tools to evaluate the barrier capability of a natural barrier system (NBS) in a nuclear waste repository is presented. The integrated risk assessment tools encompass highly detailed process models for flow and transport, probabilistic performance assessment (PA), and database management. In this paper development of an integrated tool for the modeling of far-field radionuclide transport in a generic salt repository is discussed. The tool was developed by wrapping the flow and transport reservoir simulator (FEHM) with the uncertainty quantification and optimization code (DAKOTA).
For the interim storage of used nuclear fuel, the storage casks/containers will be exposed to conditions under which considerable dust and/or atmospheric aerosols may be deposited on the surface. These dust layers may contain a sizeable portion of water soluble salts, particularly in marine environments where many interim storage systems are located. These soluble salts will deliquesce if sufficient moisture is present, resulting in the formation of potentially corrosive brine on the material surface. Experimental results have illustrated that some stainless steels, such as 304SS (a common material of construction for interim storage containers) can and will undergo localized corrosion in elevated temperature conditions where a chloride rich brine has formed on the surface. Results presented here illustrate that it is possible that stifling of localized attack will result when limited reactant is present, but additional analysis is necessary before a definite conclusion can be made.
The attached cost analyses sheets have been developed for use in planning during the Third Party Alternative study currently underway for the Sandia CREATE project. This cost analysis builds upon the previously submitted base estimate dated June 14, 2013 and includes comparison information collected during a Market Validation exercise conducted in August/September 2013.
Complex adaptive systems are central to many persistent problems locally and globally. In cases where the effects of a policy play out slowly and propagate through interdependencies with other systems, the broader view and understanding gained from complex adaptive system analyses allow us to recognise the causal relationships involved and solve persistent system-level issues. This is particularly true with the risks due to climate change, economic crises, energy disruptions and food insecurity. Climate change and the challenge of addressing the resulting global risks provides a common set of problems on which to build a global community of practice that utilises earth systems' engineering approaches and sustainability goals to understand and resolve problems in complex adaptive systems of systems. Structural adaptation under environmental stress, simple rules for entity interactions and conditiondependent behaviours are key attributes of complex systems. These attributes provide the means for creating models that behave the way the real system does and for the same reasons, improving understanding and designing effective solutions. This paper presents general concepts for infrastructure adaptation and examples of successful applications of an expanded engineering process for complex systems of systems.
This work is being performed for Matt Channon Consulting as part of the Sandia National Laboratories New Mexico Small Business Assistance Program (NMSBA). Matt Channon Consulting has requested Sandia's assistance in the design of a chemical Bunsen reactor for the reaction of SO2, I2 and H2O to produce H2SO4 and HI with a SO2 feed rate to the reactor of 50 kg/hour. Based on this value, an assumed reactor efficiency of 33%, and kinetic data from the literature, a plug flow reactor approximately 1%E2%80%9D diameter and and 12 inches long would be needed to meet the specification of the project. Because the Bunsen reaction is exothermic, heat in the amount of approximately 128,000 kJ/hr would need to be removed using a cooling jacket placed around the tubular reactor. The available literature information on Bunsen reactor design and operation, certain support equipment needed for process operation and a design that meet the specification of Matt Channon Consulting are presented.
Topological quantum computation (TQC) has emerged as one of the most promising approaches to quantum computation. Under this approach, the topological properties of a non-Abelian quantum system, which are insensitive to local perturbations, are utilized to process and transport quantum information. The encoded information can be protected and rendered immune from nearly all environmental decoherence processes without additional error-correction. It is believed that the low energy excitations of the so-called =5/2 fractional quantum Hall (FQH) state may obey non-Abelian statistics. Our goal is to explore this novel FQH state and to understand and create a scientific foundation of this quantum matter state for the emerging TQC technology. We present in this report the results from a coherent study that focused on obtaining a knowledge base of the physics that underpins TQC. We first present the results of bulk transport properties, including the nature of disorder on the 5/2 state and spin transitions in the second Landau level. We then describe the development and application of edge tunneling techniques to quantify and understand the quasiparticle physics of the 5/2 state.
Crystallographic slip planes in body centered cubic (BCC) metals are not fully understood. In polycrystals, there are additional confounding effects from grain interactions. This paper describes an experimental investigation into the effects of grain orientation and neighbors on elastic–plastic strain accumulation. In situ strain fields were obtained by performing digital image correlation (DIC) on images from a scanning electron microscope (SEM) and from optical microscopy. These strain fields were statistically compared to the grain structure measured by electron backscatter diffraction (EBSD). Spearman rank correlations were performed between effective strain and six microstructural factors including four Schmid factors associated with the <111> slip direction, grain size, and Taylor factor. Modest correlations (~10%) were found for a polycrystal tension specimen. The influence of grain neighbors was first investigated by re-correlating the polycrystal data using clusters of similarly-oriented grains identified by low grain boundary misorientation angles. Second, the experiment was repeated on a tantalum oligocrystal, with through-thickness grains. Much larger correlation coefficients were found in this multicrystal due to the dearth of grain neighbors and subsurface microstructure. Finally, a slip trace analysis indicated (in agreement with statistical correlations) that macroscopic slip often occurs on {110}<111> slip systems and sometimes by pencil glide on maximum resolved shear stress planes (MRSSP). These results suggest that Schmid factors are suitable for room temperature, quasistatic, tensile deformation in tantalum as long as grain neighbor effects are accounted for.
Progress toward predictions of the statistics of particle time-temperature histories is presented. These predictions are to be made using Lagrangian particle models within the one-dimensional turbulence (ODT) model. In the present reporting period we have further characterized the performance, behavior and capabilities of the particle dispersion models that were added to the ODT model in the first period. We have also extended the capabilities in two manners. First we provide alternate implementations of the particle transport process within ODT; within this context the original implementation is referred to as the type-I and the new implementations are referred to as the type-C and type-IC interactions. Second we have developed and implemented models for two-way coupling between the particle and fluid phase. This allows us to predict the reduced rate of turbulent mixing associated with particle dissipation of energy and similar phenomena. Work in characterizing these capabilities has taken place in homogeneous decaying turbulence, in free shear layers, in jets and in channel flow with walls, and selected results are presented.
Two classes of materials, poly(methylene diphenyl diisocyanate) or PMDI foam, and cross-linked epoxy resins, were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), to help understand the effects of aging and %E2%80%9Cbake-out%E2%80%9D. The materials were evaluated for mass loss and the onset of decomposition. In some experiments, volatile materials released during heating were analyzed via mass spectroscopy. In all, over twenty materials were evaluated to compare the mass loss and onset temperature for decomposition. Model free kinetic (MFK) measurements, acquired using variable heating rate TGA experiments, were used to calculate the apparent activation energy of thermal decomposition. From these compiled data the effects of aging, bake-out, and sample history on the thermal stability of materials were compared. No significant differences between aged and unaged materials were detected. Bake-out did slightly affect the onset temperature of decomposition but only at the highest bake-out temperatures. Finally, some recommendations for future handling are made.
The human brain (volume=1200cm3) consumes 20W and is capable of performing > 10^16 operations/s. Current supercomputer technology has reached 1015 operations/s, yet it requires 1500m^3 and 3MW, giving the brain a 10^12 advantage in operations/s/W/cm^3. Thus, to reach exascale computation, two achievements are required: 1) improved understanding of computation in biological tissue, and 2) a paradigm shift towards neuromorphic computing where hardware circuits mimic properties of neural tissue. To address 1), we will interrogate corticostriatal networks in mouse brain tissue slices, specifically with regard to their frequency filtering capabilities as a function of input stimulus. To address 2), we will instantiate biological computing characteristics such as multi-bit storage into hardware devices with future computational and memory applications. Resistive memory devices will be modeled, designed, and fabricated in the MESA facility in consultation with our internal and external collaborators.
This report summarizes LDRD project number 151365, \Dynamic Temperature Measurements with Embedded Optical Sensors". The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.
Critical infrastructures, such as electrical power plants and oil refineries, rely on programmable logic controllers (PLCs) to control essential processes. State of the art security cannot detect attacks on PLCs at the hardware or firmware level. This renders critical infrastructure control systems vulnerable to costly and dangerous attacks. WeaselBoard is a PLC backplane analysis system that connects directly to the PLC backplane to capture backplane communications between modules. WeaselBoard forwards inter-module traffic to an external analysis system that detects changes to process control settings, sensor values, module configuration information, firmware updates, and process control program (logic) updates. WeaselBoard provides zero-day exploit detection for PLCs by detecting changes in the PLC and the process. This approach to PLC monitoring is protected under U.S. Patent Application 13/947,887.
Nanocrystalline copper lms were created by both repetitive high-energy pulsed power, to produce material without internal nanotwins; and pulsed laser deposition, to produce nan- otwins. Samples of these lms were indented at ambient (298K) and cryogenic temperatures by immersion in liquid nitrogen (77K) and helium (4K). The indented samples were sectioned through the indented regions and imaged in a scanning electron microscope. Extensive grain growth was observed in the lms that contained nanotwins and were indented cryogenically. The lms that either lacked twins, or were indented under ambient conditions, were found to exhibit no substantial grain growth by visual inspection. Precession transmission elec- tron microscopy was used to con rm these ndings quantitatively, and show that 3 and 7 boundaries proliferate during grain growth, implying that these interface types play a key role in governing the extensive grain growth observed here. Molecular dynamics sim- ulations of the motion of individual grain boundaries demonstrate that speci c classes of boundaries - notably 3 and 7 - exhibit anti- or a-thermal migration, meaning that their mobilities either increase or do not change signi cantly with decreasing temperature. An in-situ cryogenic indentation capability was developed and implemented in a transmission electron microscope. Preliminary results do not show extensive cryogenic grain growth in indented copper lms. This discrepancy could arise from the signi cant di erences in con g- uration and loading of the specimen between the two approaches, and further research and development of this capability is needed.
Deflections of an impeller due to centripetal forces are calculated using finite element analysis. The lateral, or out of plane, deflections are an important design consideration for this particular impeller because it incorporates an air bearing with critical gap tolerances. The target gap distance is approximately 10 microns at a rotational velocity of 2500 rpm. The centripetal forces acting on the impeller cause it deflect in a concave fashion, decreasing the initial gap distance as a function of radial position. This deflection is characterized for a previous and updated impeller design for comparative purposes. The impact of design options such as material selection, geometry dimensions, and operating rotational velocity are also explored, followed by a sensitivity study with these parameters bounded by specific design values. A modal analysis is also performed to calculate the impeller's natural frequencies which are desired to be avoided during operation. The finite element modeling techniques continue to be exercised by the impeller design team to address specific questions and evaluate conceptual designs, some of which are included in the Appendix.
Sandia National Laboratories, Environmental Programs completed an environmental baseline survey (EBS) of 12.6 acres located at Sandia National Laboratories/California (SNL/CA) in support of the proposed Collaboration in Research and Engineering for Advanced Technology and Education (CREATE) Facility. The survey area is comprised of several parcels of land within SNL/CA, County of Alameda, California. The survey area is located within T 3S, R 2E, Section 13. The purpose of this EBS is to document the nature, magnitude, and extent of any environmental contamination of the property; identify potential environmental contamination liabilities associated with the property; develop sufficient information to assess the health and safety risks; and ensure adequate protection for human health and the environment related to a specific property.
The oxidation in air of high-purity Al foil was studied as a function of temperature using Thermogravimetric Analysis with Differential Scanning Calorimetry (TGA/DSC). The rate and/or extent of oxidation was found to be a non-linear function of the temperature. Between 650 and 750 ÀC very little oxidation took place; at 850 ÀC oxidation occurred after an induction period, while at 950 ÀC oxidation occurred without an induction period. At oxidation temperatures between 1050 and 1150 ÀC rapid passivation of the surface of the aluminum foil occurred, while at 1250 ÀC and above, an initial rapid mass increase was observed, followed by a more gradual increase in mass. The initial rapid increase was accompanied by a significant exotherm. Cross-sections of oxidized specimens were characterized by scanning electron microscopy (SEM); the observed alumina skin thicknesses correlated qualitatively with the observed mass increases.
This report presents plots of specific heat, enthalpy, entropy, and Gibbs free energy for 1439 species in the JCZS2i database. Included in this set of species are 496 condensed-phase species and 943 gas-phase species. The gas phase species contain 80 anions and 112 cations for a total of 192 ions. The JCZS2i database is used in conjunction with the TIGER thermochemical code to predict thermodynamic states from ambient conditions to high temperatures and pressures. Predictions from the TIGER code using the JCZS2i database can be used in shock physics codes where temperatures may be as high as 20,000 K and ions may be present. Such high temperatures were not considered in the original JCZS database, and extrapolations made for these temperatures were unrealistic. For example, specific heat would sometimes go negative at high temperatures which fails the definition of specific heat. The JCZS2i database is a new version of the JCZS database that is being created to address these inaccuracies. The purpose of the current report is to visualize the high temperature extrapolations to insure that the specific heat, enthalpy, entropy, and Gibbs free energy predictions are reasonable up to 20,000 K.
This work was partially supported by the Sandia National Laboratories, Laboratory Directed Research and Development (LDRD) fellowship program in conjunction with Texas A&M University (TAMU). The research described herein is the work of Kathryn M. Schreiner (Katie) and her advisor, Thomas S. Bianchi and represents a concise description of Katies dissertation that was submitted to the TAMU Office of Graduate Studies in May 2013 in partial fulfillment of her doctorate of philosophy degree. High Arctic permafrost soils contain a massive amount of organic carbon, accounting for twice as much carbon as what is currently stored as carbon dioxide in the atmosphere. However, with current warming trends this sink is in danger of thawing and potentially releasing large amounts of carbon as both carbon dioxide and methane into the atmosphere. It is difficult to make predictions about the future of this sink without knowing how it has reacted to past temperature and climate changes. This project investigated long term, fine scale particulate organic carbon (POC) delivery by the high-Arctic Colville River into Simpsons Lagoon in the near-shore Beaufort Sea. Modern POC was determined to be a mixture of three sources (riverine soils, coastal erosion, and marine). Downcore POC measurements were performed in a core close to the Colville River output and a core close to intense coastal erosion. Inputs of the three major sources were found to vary throughout the last two millennia, and in the Colville River core covary significantly with Alaskan temperature reconstructions.
Metal particle beds have recently become a major technique for hydrogen storage. In order to extract hydrogen from such beds, it is crucial to understand the decomposition kinetics of the metal hydride. We are interested in obtaining a a better understanding of the uranium hydride (UH3) decomposition kinetics. We first developed an empirical model by fitting data compiled from different experimental studies in the literature and quantified the uncertainty resulting from the scattered data. We found that the decomposition time range predicted by the obtained kinetics was in a good agreement with published experimental results. Secondly, we developed a physics based mathematical model to simulate the rate of hydrogen diffusion in a hydride particle during the decomposition. We used this model to simulate the decomposition of the particles for temperatures ranging from 300K to 1000K while propagating parametric uncertainty and evaluated the kinetics from the results. We compared the kinetics parameters derived from the empirical and physics based models and found that the uncertainty in the kinetics predicted by the physics based model covers the scattered experimental data. Finally, we used the physics-based kinetics parameters to simulate the effects of boundary resistances and powder morphological changes during decomposition in a continuum level model. We found that the species change within the bed occurring during the decomposition accelerates the hydrogen flow by increasing the bed permeability, while the pressure buildup and the thermal barrier forming at the wall significantly impede the hydrogen extraction.
People save for retirement throughout their career because it is virtually impossible to save all youll need in retirement the year before you retire. Similarly, without installing incremental amounts of clean fossil, renewable or transformative energy technologies throughout the coming decades, a radical and immediate change will be near impossible the year before a policy goal is set to be in place. Therefore, our research question is, To meet our desired technical and policy goals, what are the factors that affect the rate we must install technology to achieve these goals in the coming decades? Existing models do not include full regulatory constraints due to their often complex, and inflexible approaches to solve for optimal engineering instead of robust and multidisciplinary solutions. This project outlines the theory and then develops an applied software tool to model the laboratory-to-market transition using the traditional technology readiness level (TRL) framework, but develops subsequent and a novel regulatory readiness level (RRL) and market readiness level (MRL). This tool uses the ideally-suited system dynamics framework to incorporate feedbacks and time delays. Future energy-economic-environment models, regardless of their programming platform, may adapt this software model component framework or module to further vet the likelihood of new or innovative technology moving through the laboratory, regulatory and market space. The prototype analytical framework and tool, called the Technology, Regulatory and Market Readiness Level simulation model (TRMsim) illustrates the interaction between technology research, application, policy and market dynamics as they relate to a new or innovative technology moving from the theoretical stage to full market deployment. The initial results that illustrate the models capabilities indicate for a hypothetical technology, that increasing the key driver behind each of the TRL, RRL and MRL components individually decreases the time required for the technology to progress through each component by 63, 68 and 64%, respectively. Therefore, under the current working assumptions, to decrease the time it may take for a technology to move from the conceptual stage to full scale market adoption one might consider expending additional effort to secure regulatory approval and reducing the uncertainty of the technologys demand in the marketplace.