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At least 1,171 records · Page 65

Quantitative Reflectance Spectra of Solid Powders as a Function of Particle Size

We have recently developed vetted methods for obtaining quantitative infrared directional-hemispherical reflectance spectra using a commercial integrating sphere. In this paper, the effects of particle size on the spectral properties are analyzed for several samples such as ammonium sulfate, calcium carbonate, and sodium sulfate as well as one organic compound, lactose. We prepared multiple size fractions for each sample and confirmed the mean sizes using optical microscopy. Most species displayed a wide range of spectral behavior depending on the mean particle size. General trends of reflectance vs. particle size are observed such as increased albedo for smaller particles: for most wavelengths, the reflectivity drops with increased size, sometimes displaying a factor of 4 or more drop in reflectivity along with a loss of spectral contrast. In the longwave infrared, several species with symmetric anions or cations exhibited reststrahlen features whose amplitude was nearly invariant with particle size, at least for intermediate- and large-sized sample fractions; that is, > ~150 microns. Trends of other types of bands (Christiansen minima, transparency features) are also investigated as well as quantitative analysis of the observed relationship between reflectance vs. particle diameter.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Rapid simulations of hyperspectral near-field images of three-dimensional heterogeneous surfaces – part II

The modeling of the near-field interaction in the scattering-type scanning near-field optical microscope (s-SNOM) is rapidly advancing, although an accurate yet versatile modeling framework that can be easily adapted to various complex situations is still lacking. In this work, we propose a time-efficient numerical scheme in the quasi-electrostatic limit to capture the tip-sample interaction in the near field. This method considers an extended tip geometry, which is a significant advantage compared to the previously reported method based on the point-dipole approximation. Using this formalism, we investigate, among others, nontrivial questions such as uniaxial and biaxial anisotropy in the near-field interaction, the relationship between various experimental parameters (e.g. tip radius, tapping amplitude, etc.), and the tip-dependent spatial resolution. The demonstrated method further sheds light on the understanding of the contrast mechanism in s-SNOM imaging and spectroscopy, while also representing a valuable platform for future quantitative analysis of the experimental observations.

Chen, Xinzhong (ORCID:0000000261033848)↗

Photoluminescence probing of light absorption centers at silica laser damage

We use photoluminescence (PL) imaging to study damage growth precursors within laser damage sites on the surface of silica. Damage site evolution is induced by multiple shots of UV nanosecond pulsed laser at various energy densities and monitored throughout the early stages of growth. Wide-field PL imaging rapidly locates microscopic light absorption centers within the silica damage site. Our quantitative analysis shows that damage sites with strong local PL intensity show a higher probability of growth upon subsequent laser pulses. Scanning electron microscopy (SEM) paired with a study of PL spectrum shows that the strong PL intensity appears from the subsurface fractures with high defect density, which provides a local light absorption center leading to significant damage growth. We believe that this result offers an efficient optical damage mitigation strategy by providing a rapid and non-destructive optical inspection approach.

36 MATERIALS SCIENCE↗

Value of Information References

This file contains a list of relevant references on value of information (VOI) in RIS format. VOI provides a quantitative analysis to evaluate the outcome of the combined technologies (seismology, hydrology, geodesy) used to monitor Brady's Geothermal Field.

15 GEOTHERMAL ENERGY↗

Utilization of traceable standards to validate plutonium isotopic purification and separation of plutonium progeny using AG MP-1M resin for nuclear forensic investigations

Radio-chronometric studies on plutonium (Pu) materials require independent measurement of the Pu (parent) content and isotopic distribution as well as concentration and isotopic distribution of the plutonium isotopic decay products. We performed a series of experiments to demonstrate the consistency of separations using the Lewatit MP 800 macroporous anion exchange resin and the AG MP-1M resin with traceable Pu isotopic certified reference material (CRM) standards 136, 137, 138, and 126-A. Two different mesh-sizes of the AG MP-1M resin were tested and the 50–100 mesh size resin was found to work more efficiently for the separation task. Both Lewatit and AG MP-1M resins were found to perform satisfactorily for quantitatively extracting the americium (Am) and uranium (U) progeny as well as gallium (Ga) present as a tracer in the Pu material. Both resins were effective in removing isobaric interferences from the Pu fraction used in isotopic measurements by thermal ionization mass spectrometry (TIMS). To address the co-elution of uranium and gallium, Alizarin red S (ARS) was used as a colorimetric dye to determine the behavior of UO 2 2+ and Ga 3+ on AG MP-1M resin with various acidic solutions as eluents using UV–vis spectra. Poor resolution of these peaks complicated quantitative analysis by UV–vis spectroscopy, but these results were informative in planning automated separation experiments by HPLC. LA-UR-24-28919.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Nuclear forensics of a non-traditional sample: Neptunium

Recent nuclear forensics cases have focused primarily on plutonium (Pu) and uranium (U) materials. By definition however, nuclear forensics can apply to any diverted nuclear material. This includes neptunium (Np), an internationally safeguarded material like Pu and U, that could offer a nuclear security concern if significant quantities were found outside of regulatory control. This case study couples scanning electron microscopy (SEM) with quantitative analysis using newly developed specialized software, to evaluate a non-traditional nuclear forensic sample of Np. Here, the results of the morphological analyses were compared with another Np sample of known pedigree, as well as other traditional actinide materials in order to determine potential processing and point-of-origin.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

A Comparison of Compressed Sensing and Sparse Recovery Algorithms Applied to Simulation Data

The move toward exascale computing for scientific simulations is placing new demands on compression techniques. It is expected that the I/O system will not be able to support the volume of data that is expected to be written out. To enable quantitative analysis and scientific discovery, we are interested in techniques that compress high-dimensional simulation data and can provide perfect or near-perfect reconstruction. In this paper, we explore the use of compressed sensing (CS) techniques to reduce the size of the data before they are written out. Using large-scale simulation data, we investigate how the sufficient sparsity condition and the contrast in the data affect the quality of reconstruction and the degree of compression. Also, we provide suggestions for the practical implementation of CS techniques and compare them with other sparse recovery methods. Finally, our results show that despite longer times for reconstruction, compressed sensing techniques can provide near perfect reconstruction over a range of data with varying sparsity.

97 MATHEMATICS AND COMPUTING↗

Technical Assessment of the Passive Neutron Enrichment Meter (PNEM) for an Unattended Cylinder Verification Station (UCVS)

The International Atomic Energy Agency (IAEA) is exploring the potential roles of an Unattended Cylinder Verifications Station (UCVS) in a new generation of safeguards technology for uranium enrichment plants. The UCVS is envisioned to combine an operator accountancy scale, a nondestructive assay (NDA) system such as the Passive Neutron Enrichment Meter (PNEM), a cylinder identification system, and a surveillance system for verification of product, feed, and tails cylinders as well as continuity of knowledge at material balance area boundaries. The IAEA has identified several preliminary requirements and development questions for the UCVS. Specifically, the IAEA has identified the accuracy of the enrichment assay as the key metric for the NDA system with uncertainty targets of 3%, 6%, and 9% on product, feed, and tails cylinders, respectively. The NDA system should also provide full volume interrogation of the cylinders in order to ensure detection of partial defects within the cylinder. The development questions are concerned primarily with the sources and magnitude of the uncertainty and quantitative analysis of the interrogation depth and partial defect sensitivity. The objective of this report is to address these requirements and questions based on Monte Carlo modeling and field trial experience with the PNEM.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

The Use of Geomorphometrics for Geologic Site Characterization

The Problem: Developing an accurate geologic site characterization is difficult for denied-access sites. A good understanding of the geology (both in terms of the rock types and the fracture networks) is required for event evaluation (e.g., modulation of seismic signals from the source), planning of treaty monitoring sensors (fracture play a key role in the gas migration pathways), and evaluation of containment strategies. The Hypothesis: Quantitative analysis of terrain characteristics provides a way to relate the topography (easily obtained at high resolution) to surface geology. The Method: Integration of Terrain Complexity Index (TCI, derived from surface roughness) with drainage patterns and texture to produce a "predicted" geologic map. The viability of this method was evaluated by applying the algorithm to an area of know geology (Area 15 at the Nevada Test Site - NNSS). A 10-meter digital elevation model (DEM) was used for this evaluation. The Application: We have demonstrated the utility of this method by developing an improved surface geologic map for the North Korean Test Site using a 5-meter DEM. Why Now: Improved geologic characterization of potential nuclear test sites in a number of countries is needed for a number of Nonproliferation objectives. What's Needed Next: 1) A more robust and automated interpretation algorithm for the drainage analysis aspect; 2) improved data fusion of the TCI with drainage patterns; and 3) evaluation of the potential for fracture mapping in granite using a very high resolution DEM at the NNSS site (a 1-meter DEM in on order).

58 GEOSCIENCES↗

Review of Destructive Assay Methods for Nuclear Materials Characterization from the Three Mile Island (TMI) Fuel Debris

This report provides a summary of the literature review that was performed and based on previous work performed at the Idaho National Laboratory studying the Three Mile Island 2 (TMI-2) nuclear reactor accident, specifically the melted fuel debris. The purpose of the literature review was to document prior published work that supports the feasibility of the analytical techniques that were developed to provide quantitative results of the make-up of the fuel and reactor component debris located inside and outside the containment. The quantitative analysis provides a technique to perform nuclear fuel accountancy measurements

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

BEopt-CA (Ex): A Tool for Optimal Integration of EE, DR and PV in Existing California Homes

Opportunities for combining energy efficiency, demand response, and energy storage with PV are often missed, because the required knowledge and expertise for these different technologies exist in separate organizations or individuals. Furthermore, there is a lack of quantitative tools to optimize energy efficiency, demand response and energy storage with PV, especially for existing buildings. As technology costs evolve (e.g., the ongoing reduction in the cost of PV), design strategies need to be adjusted accordingly based on quantitative analysis.

14 SOLAR ENERGY↗

Characterization of biofilm in 200W fluidized bed reactors

Contaminated groundwater beneath the 200 West Area at the Hanford Site in Southeast Washington is currently being treated using a pump and treat system to remove organics, inorganics, radionuclides, and metals. A granular activated carbon-based fluidized bed reactor (FBR) has been added to remove nitrate, hexavalent chromium and carbon tetrachloride. Initial analytical results indicated the microorganisms effectively reduced many of the contaminants to less than cleanup levels. However shortly thereafter operational upsets of the FBR include carbon carry over, over production of microbial extracellular polymeric substance (biofilm) materials, and over production of hydrogen sulfide. As a result detailed investigations were undertaken to understand the functional diversity and activity of the microbial community present in the FBR over time. Molecular analyses including terminal restriction fragment length polymorphism analysis, quantitative polymerase chain reaction and fluorescent in situ hybridization analyses were performed on the microbial community extracted from the biofilm within the bed and from the inoculum, to determine functional dynamics of the FBR bed over time and following operational changes. Findings from these analyses indicated: 1) the microbial community within the bed was completely different than community used for inoculation, and was likely from the groundwater; 2) analyses early in the testing showed an FBR community dominated by a few Curvibacter and Flavobacterium species; 3) the final sample taken indicated that the microbial community in the FBR bed had become more diverse; and 4) qPCR analyses indicated that bacteria involved in nitrogen cycling, including denitrifiers and anaerobic ammonia oxidizing bacteria, were dominant in the bed. These results indicate that molecular tools can be powerful for determining functional diversity within FBR type reactors. Coupled with micronutrient, influent and effluent chemistry evaluations, a more complete understanding of the balance between system additions (nutrients, groundwater) and biology can be achieved, thus increasing long-term predictions of performance. These analyses uniquely provide information that can be used in optimizing the overall performance, efficiency, and stability of the system both in real time as well as over the long-term, as the system design is altered or improved and/or new streams are added.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

Final Report: Molecular mechanisms and kinetics of microbial anaerobic nitrate-dependent U(IV) and Fe(II) oxidation

In this project, we combined molecular genetic, spectroscopic, and microscopic techniques with kinetic and reactive transport studies to describe and quantify biotic and abiotic mechanisms underlying anaerobic, nitrate-dependent U(IV) and Fe(II) oxidation, which influences the long-term efficacy of in situ reductive immobilization of uranium at DOE sites. In these studies, Thiobacillus denitrificans, an autotrophic bacterium that catalyzes anaerobic U(IV) and Fe(II) oxidation, was used to examine coupled oxidation-reduction processes under either biotic (enzymatic) or abiotic conditions in batch and column experiments with biogenically produced UIVO2(s). Synthesis and quantitative analysis of coupled chemical and transport processes were done with the reactive transport modeling code Crunchflow. Research focused on identifying the primary redox proteins that catalyze metal oxidation, environmental factors that influence protein expression, and molecular-scale geochemical factors that control the rates of biotic and abiotic oxidation.

54 ENVIRONMENTAL SCIENCES↗

Energy-Efficiency and Air-Pollutant Emissions-Reduction Opportunities for the Ammonia Industry in China

As one of the most energy-intensive and polluting industries, ammonia production is responsible for significant carbon dioxide (CO 2 ) and air-pollutant emissions. Although many energy-efficiency measures have been proposed by the Chinese government to mitigate greenhouse gas emissions and improve air quality, lack of understanding of the cost-effectiveness of such improvements has been a barrier to implementing these measures. Assessing the costs, benefits, and cost-effectiveness of different energy-efficiency measures is essential to advancing this understanding. In this study, a bottom-up energy conservation supply curve model is developed to estimate the potential for energy savings and emissions reductions from 26 energy-efficiency measures that could be applied in China’s ammonia industry. Cost-effective implementation of these measures saves a potential 271.5 petajoules/year for fuel and 5,443 gigawatt-hours/year for electricity, equal to 14% of fuel and 14% of electricity consumed in China’s ammonia industry in 2012. These reductions could mitigate 26.7 million tonnes of CO 2 emissions. This study also quantifies the co-benefits of reducing air-pollutant emissions and water use that would result from saving energy in China’s ammonia industry. This quantitative analysis advances our understanding of the cost-effectiveness of energy-efficiency measures and can be used to augment efforts to reduce energy use and environmental impacts.

54 ENVIRONMENTAL SCIENCES↗

Development of a General Form CO 2 and Brine Flux Input Model

The National Risk Assessment Partnership (NRAP) project is developing a science-based toolset for the quantitative analysis of the potential risks associated with changes in groundwater chemistry from CO 2 injection. In order to address uncertainty probabilistically, NRAP is developing efficient, reduced-order models (ROMs) as part of its approach. These ROMs are built from detailed, physics-based process models to provide confidence in the predictions over a range of conditions. The ROMs are designed to reproduce accurately the predictions from the computationally intensive process models at a fraction of the computational time, thereby allowing the utilization of Monte Carlo methods to probe variability in key parameters. This report presents the procedures used to develop a generalized model for CO 2 and brine leakage fluxes based on the output of a numerical wellbore simulation. The resulting generalized parameters and ranges reported here will be used for the development of third-generation groundwater ROMs.

58 GEOSCIENCES↗

Final Report: Proteomic study of brassinosteroid responses in Arabidopsis

The steroid hormone brassinosteroid (BR) is a major growth-promoting phytohormone. The specific aim of the current project is to identify BR-regulated proteins and characterize their functions in various aspects of plant growth, development, and adaptation. Our research has significantly advanced our understanding of how BR signal is transduced from the receptor at the cell surface to changes of nuclear gene expression and other cellular responses such as vesicle trafficking, as well as developmental transitions such as seed germination and flowering. We have also developed effective proteomic methods for quantitative analysis of protein phosphorylation and for identification of glycosylated proteins. Through this DOE funding, we have performed several proteomic experiments and made major discoveries.

59 BASIC BIOLOGICAL SCIENCES↗

Analyses in Support of Risk-Informed Natural Gas Vehicle Maintenance Facility Codes and Standards: Phase II

Safety standards development for maintenance facilities of liquid and compressed natural gas fueled vehicles is required to ensure proper facility design and operating procedures. Standard development organizations are utilizing risk-informed concepts to develop natural gas vehicle (NGV) codes and standards so that maintenance facilities meet acceptable risk levels. The present report summarizes Phase II work for existing NGV repair facility code requirements and highlights inconsistencies that need quantitative analysis into their effectiveness. A Hazardous and Operability study was performed to identify key scenarios of interest using risk ranking. Detailed simulations and modeling were performed to estimate the location and behavior of natural gas releases based on these scenarios. Specific code conflicts were identified, and ineffective code requirements were highlighted and resolutions proposed. These include ventilation rate basis on area or volume, as well as a ceiling offset which seems ineffective at protecting against flammable gas concentrations. ACKNOWLEDGEMENTS The authors gratefully acknowledge Bill Houf (SNL -- Retired) for his assistance with the set-up and post-processing of the numerical simulations. The authors also acknowledge Doug Horne (retired) for his helpful discussions. We would also like to acknowledge the support from the Clean Cities program of DOE's Vehicle Technology Office.

03 NATURAL GAS↗

Video Magic

Los Alamos National Laboratory has invented VideoMagic, a technology that automatically extracts resonant frequencies, vibrational mode shapes and damping ratios from video of vibrating structures.This technique estimates full-field mode shapes at high spatial resolution. This allows quantitative analysis of mode shapes for detecting minute stiffness losses in structures, using pixels as video sensors.

47 OTHER INSTRUMENTATION↗