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At least 91 records · Page 5

New prospects for PV powered water desalination plants: case studies in Saudi Arabia: New prospects for PV powered water desalination plants

Increased water demand and increased drought episodes in the Middle East and other regions necessitate an expansion in desalination projects and create a great market opportunity for photovoltaics (PV). PV-powered desalination has previously been regarded as not being a cost-competitive solution when compared with conventionally powered desalination; however, the decline in PV costs over the last few years has changed this outlook. Here, this article presents up-to-date performance and cost analysis of reverse osmosis (RO) desalination powered with PV connected to the Saudi Arabian grid. Reference cases include relatively small (i.e., producing 6550 m 3 water per day) and large (i.e., 190 000 m 3 /day) desalination plants using seawater at a salinity of 40 000 ppm. We used data from a King Abdullah University for Science and Technology presentation and Hybrid Optimization Model for Electric Renewables 2.81 Energy Modeling Software (HOMER Energy LLC) in tandem with Desalination Economic Evaluation Program 4.0 (International Atomic Energy Agency) desalination software to analyze the techno-economic feasibility of these plants. The first phase of our work entailed a comparison between dual-axis high concentration PV (CPV) equipped with triple junction III/V solar cells and CdTe PV-powered RO systems. The estimated levelized cost of electricity from CPV is 0.16/kWh dollars, whereas that from CdTe PV is $0.10/kWh dollars and 0.09/kWh dollars for fixed-tilt and one-axis tracking systems, respectively. These costs are higher than the price of diesel-based grid electricity in the region because diesel fuel is heavily subsidized in Saudi Arabia.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Rapid fusion method for the determination of refractory thorium and uranium isotopes in soil samples

Recently, approximately 80% of participating laboratories failed to accurately determine uranium isotopes in soil samples in the U.S Department of Energy Mixed Analyte Performance Evaluation Program (MAPEP) Session 30, due to incomplete dissolution of refractory particles in the samples. Failing laboratories employed acid dissolution methods, including hydrofluoric acid, to recover uranium from the soil matrix. The failures illustrate the importance of rugged soil dissolution methods for the accurate measurement of analytes in the sample matrix. A new rapid fusion method has been developed by the Savannah River National Laboratory (SRNL) to prepare 1-2 g soil sample aliquots very quickly, with total dissolution of refractory particles. Soil samples are fused with sodium hydroxide at 600 ºC in zirconium crucibles to enable complete dissolution of the sample. Uranium and thorium are separated on stacked TEVA and TRU extraction chromatographic resin cartridges, prior to isotopic measurements by alpha spectrometry on cerium fluoride microprecipitation sources. Plutonium can also be separated and measured using this method. Batches of 12 samples can be prepared for measurement in <5 hours.

54 ENVIRONMENTAL SCIENCES↗

Screening and Validation of Molecular Targeted Radiosensitizers

The development of molecular targeted drugs with radiation and chemotherapy is critically important for improving the outcomes of patients with hard-to-treat, potentially curable cancers. However, too many preclinical studies have not translated into successful radiation oncology trials. Major contributing factors to this insufficiency include poor reproducibility of preclinical data, inadequate preclinical modeling of intertumoral genomic heterogeneity that influences treatment sensitivity in the clinic, and a reliance on tumor growth delay instead of local control (TCD50) endpoints. There exists an urgent need to overcome these barriers to facilitate successful clinical translation of targeted radiosensitizers. To this end, we have used 3-dimensional (3D) cell culture assays to better model tumor behavior in vivo. Examples of successful prediction of in vivo effects with these 3D assays include radiosensitization of head and neck cancers by inhibiting epidermal growth factor receptor or focal adhesion kinase signaling, and radioresistance associated with oncogenic mutation of KRAS. To address the issue of tumor heterogeneity, we leveraged institutional resources that allow high-throughput 3D screening of radiation combinations with small-molecule inhibitors across genomically characterized cell lines from lung, head and neck, and pancreatic cancers. This high-throughput screen is expected to uncover genomic biomarkers that will inform the successful clinical translation of targeted agents from the National Cancer Institute Cancer Therapy Evaluation Program portfolio and other sources. Screening “hits” need to be subjected to refinement studies that include clonogenic assays, addition of disease-specific chemotherapeutics, target/biomarker validation, and integration of patient-derived tumor models. The chemoradiosensitizing activities of the most promising drugs should be confirmed in TCD50 assays in xenograft models with or without relevant biomarker and using clinically relevant radiation fractionation. We predict that appropriately validated and biomarker-directed targeted therapies will have a higher likelihood than past efforts of being successfully incorporated into the standard management of hard-to-treat tumors.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

Toxicokinetics and toxicity of atorvastatin in dogs

HMG-CoA reductase inhibitors (e.g., statins) are an important clinical option to lower cholesterol and treat co-morbidities. Atorvastatin is the most prescribed statin and has obtained generic status. We recently had a clinical development program evaluating a combination of atorvastatin with a GPR119 agonist as a treatment for dyslipidemia, where toxicological evaluations in dogs were completed. There were several challenges related to selecting doses for atorvastatin, including understanding the dose–exposure relationship from different drug forms used by the innovator in their general toxicology studies, bioanalytical assays that did not separate and quantify parent from metabolites, and high variability in the systemic exposures following oral dosing. The studies in this report characterized the toxicokinetics and toxicity of atorvastatin in the dog for up to 13-weeks. Overall, there were no notable differences in the toxicokinetics of atorvastatin or the two active hydroxylated metabolites between the sexes at Week 13. However, systemic exposures were markedly lower at Week 13 compared to that observed at Week 4, suggesting induction of metabolism or reduced absorption from the gastrointestinal tract following oral dosing. Changes in laboratory chemistries included increased liver enzyme levels and lower cholesterol levels. Histopathologic evaluation revealed multifocal minimal to slight hemorrhages in the submucosa of the gallbladder; all findings were reversible. The information from these studies along with the existing clinical experience with atorvastatin can be used to design robust toxicology studies in dogs and reduce animal use. - Highlights: • Atorvastatin is given to reduce cholesterol and is available as a generic drug. • Co-dosing of multiple products to treat hypercholesterolemia is increasing. • This work characterized the toxicokinetics and toxicity of atorvastatin in dogs. • The toxicokinetics of two hydroxylated metabolites were determined. • Recommendations on the dose–exposure relationship in dog are provided.

60 APPLIED LIFE SCIENCES↗

Modeling the potential effects of rooftop solar on household energy burden in the United States

Policymakers at the federal and state level have begun to incorporate energy burden into equity goals and program evaluations, aiming to reduce energy burden below a high level of 6% for lower income households in the United States. Pairing an empirical household-level dataset spanning United States geographies together with modeled hourly energy demand curves, we show that rooftop solar reduces energy burden across a majority of adopters during our study period from a median of 3.3% to 2.6%. For low- and moderate-income adopters (at or below 80% and 120% of area median income, respectively), solar reduces median 2021 energy burden from 7.7% to 6.2%, and 4.1% to 3.3%, respectively. Importantly, solar reduces the rate of high or severe energy burden from 67% of all low-income households before adoption to 52% of households following adoption, and correspondingly from 21% to 13% for moderate-income households. Here, we show rooftop solar can support policy goals to reduce energy burden along with strategies such as weatherization and bill assistance.

14 SOLAR ENERGY↗

Comparative evaluation of analogue front-end designs for the CMS Inner Tracker at the High Luminosity LHC

The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiation tolerant pixel detector able to sustain high particle rates with high efficiency and a small fraction of spurious pixel hits. The test results showed that all three analogue front-ends presented strong points, but also limitations. The Differential front-end demonstrated very low noise, but the threshold tuning became problematic after irradiation. Moreover, a saturation in the preamplifier feedback loop affected the return of the signal to baseline and thus increased the dead time. The Synchronous front-end showed very good timing performance, but also higher noise. For the Linear front-end all of the parameters were within specification, although this design had the largest time walk. This limitation was addressed and mitigated in an improved design. The analysis of the advantages and disadvantages of the three front-ends in the context of the CMS Inner Tracker operation requirements led to the selection of the improved design Linear front-end for integration in the final CMS readout chip.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

ANALYSIS OF SUITABLE METHODOLOGIES FOR COMPRESSOR MASS FLOW RATE CORRECTION TO OTHER SUPERHEAT LEVELS AND REFRIGERANTS

This paper investigates the impact of suction conditions and refrigerant on scroll compressor mass flow rate by using calorimeter tests from AHRI-11 and AHRI-21 reports, published by AHRI's Low-GWP Alternative Refrigerants Evaluation program. Two Copeland scroll compressors (20 and 51 cm3) have been analyzed including different suction conditions (SH = 11K, SH = 22K, Ti = 18ºC) and several refrigerants (R134a, R32, R410A, R404A, etc.). Previous studies have explored response surfaces for energy consumption and mass flow rate variables. This study aims to expand the analysis by identifying the optimal approach to extrapolate mass flow rate from specific suction conditions to others SH or suction temperature levels and refrigerants. The current compressor characterization standard relies on the 1981 Dabiri correlation to correct compressor mass flow rate with suction conditions. Thus, this study aims to assess the adequacy of this correction and explore alternative correction methods for improved results.

Marchante Avellaneda, Javier↗

TEST REPORT #21: Compressor Calorimeter Test of R-404A Alternatives ARM-31a, D2Y-65, L-40, and R32/ R-134a (50/50)

As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of four lower-GWP alternative refrigerants, ARM-31a, D2Y-65, L-40, and R-32 + R-134a mixture, to that of refrigerant R-404A (baseline) in a scroll compressor designed for medium temperature refrigeration applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-404A and having a nominal rated capacity of 23,500 Btu/hr. Tests were conducted over a suction dew point temperature range of -10°F to 35°F in 5°F increments and a discharge dew point temperature range of 70°F to 140°F in 10°F increments. All the tests were performed with 20°F superheat, 40°F superheat, and 65°F suction temperature. A liquid subcooling level of 10°F to 15°F was maintained for all the test conditions. However, the cooling capacities reported in this study are normalized for 0°F subcooling. The tests showed that the compressor energy efficiency ratio (EER) and cooling capacity with all four alternative refrigerants tested are higher at higher saturation suction and saturation discharge temperature and lower at lower saturation suction and saturation discharge temperature, compared to that of R-404A. Discharge temperatures of all the alternative refrigerants were higher than that of R-404A at all test conditions.

Alternative Refrigerants↗

Determining Remaining Useful Life of Aging Cables in Nuclear Power Plants – Interim Study FY13

The most important criterion for cable performance is its ability to withstand a design-basis accident. With nearly 1000 km of power, control, instrumentation, and other cables typically found in an NPP, it would be a significant undertaking to inspect all of the cables. Degradation of the cable jacket, electrical insulation, and other cable components is a key issue that is likely to affect the ability of the currently installed cables to operate safely and reliably for another 20 to 40 years beyond the initial operating life. The development of one or more nondestructive evaluation (NDE) techniques and supporting models that could assist in determining the remaining life expectancy of cables or their current degradation state would be of significant interest. The ability to nondestructively determine material and electrical properties of cable jackets and insulation without disturbing the cables or connections has been deemed essential. Currently, the only technique accepted by industry to measure cable elasticity (the gold standard for determining cable insulation degradation) is the indentation measurement. All other NDE techniques are used to find flaws in the cable and do not provide information to determine the current health or life expectancy. There is no single NDE technique that can satisfy all of the requirements needed for making a life-expectancy determination, but a wide range of methods have been evaluated for use in NPPs as part of a continuous evaluation program. The commonly used methods are indentation and visual inspection, but these are only suitable for easily accessible cables. Several NDE methodologies using electrical techniques are in use today for flaw detection but there are none that can predict the life of a cable. There are, however, several physical and chemical ptoperty changes in cable insulation as a result of thermal and radiation damage. In principle, these properties may be targets for advanced NDE methods to provide early warning of aging and degradation. Examples of such key indicators include changes in chemical structure, mechanical modulus, and dielectric permittivity. While some of these indicators are the basis of currently used technologies, there is a need to increase the volume of cable that may be inspected with a single measurement, and if possible, to develop techniques for in-situ inspection (i.e., while the cable is in operation). This is the focus of the present report.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Compressor Calorimeter Test of R-410A Alternative: R-32/134a Mixture Using a Scroll Compressor

As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares the performance of lower-GWP alternative refrigerant R-32 + R-134a mixture, to that of refrigerant R-410A (baseline) in a scroll compressor designed for air-conditioning and heat pump applications. These comparisons were carried out via compressor calorimeter tests performed on a compressor designed for refrigerant R-410A and having a nominal rated capacity of 21,300 Btu/hr. Tests were conducted over a suction dew point temperature range of 10 F to 55 F in 5 F increments and a discharge dew point temperature range of 70 F to 140 F in 10 F increments. All the tests were performed with 20 F superheat, 40 F superheat, and 65 F suction temperature. A liquid subcooling level of 15 F was maintained for all the test conditions. The tests showed that the discharge temperature of the alternative refrigerant was higher than that of R-410A at all test conditions. Also, the energy efficiency ratio (EER) and cooling capacity of compressor using the alternative refrigerant were slightly lower in comparison to that of R-410A.

Alternative Refrigerants↗

A complexity science-based framework for global joint operations analysis to support force projection: LDRD Final Report

The military is undergoing a significant transformation as it modernizes for the information age and adapts to address an emerging asymmetric threat beyond traditional cold war era adversaries. Techniques such as traditional large-scale, joint services war gaming analysis are no longer adequate to support program evaluation activities and mission planning analysis at the enterprise level because the operating environment is evolving too quickly. New analytical capabilities are necessary to address modernization of the Department of Defense (DoD) enterprise. This presents significant opportunity to Sandia in supporting the nation at this transformational enterprise scale. Although Sandia has significant experience with engineering system of systems (SoS) and Complex Adaptive System of Systems (CASoS), significant fundamental research is required to develop modeling, simulation and analysis capabilities at the enterprise scale. This report documents an enterprise modeling framework which will enable senior level decision makers to better understand their enterprise and required future investments.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

INL Seismic Monitoring Annual Report: January 1, 2012 - December 31, 2012

During 2012, the Idaho National Laboratory Seismic Monitoring Program evaluated 17,329 independent triggers that included earthquakes from around the world, the western United States, and local region of the Snake River Plain. Seismologists located 1,460 earthquakes and man-made blasts within and near the 161-km (or 100-mile) radius of the Idaho National Laboratory. Of these earthquakes, 16 had small-to-moderate size magnitudes (M) from 3.0 to 3.6. Within the 161-km radius, the majority of 695 earthquakes (M < 3.6) occurred in the active regions of the Basin and Range Provinces adjacent to the eastern Snake River Plain. Only 11 microearthquakes occurred within the Snake River Plain, four of which occurred in Craters of the Moon National Monument. The earthquakes had magnitudes from 1.0 to 1.7 and occurred at deep depths (11-24 km). Two events with magnitudes less than 1.0 occurred within the Idaho National Laboratory boundaries and had depths less than 10 km.

58 GEOSCIENCES↗

Geothermal Exploration of Newberry Volcano, Oregon

Davenport Newberry (Davenport) has completed 8 years of exploration for geothermal energy on Newberry Volcano in central Oregon. Two deep exploration test wells were drilled by Davenport on the west flank of the volcano, one intersected a hydrothermal system; the other intersected isolated fractures with no hydrothermal interconnection. Both holes have bottom-hole temperatures near or above 315°C (600°F). Subsequent to deep test drilling an expanded exploration and evaluation program was initiated. These efforts have included reprocessing existing data, executing multiple geological, geophysical, geochemical programs, deep exploration test well drilling and shallow well drilling. The efforts over the last three years have been made possible through a DOE Innovative Exploration Technology (IET) Grant 109, designed to facilitate innovative geothermal exploration techniques. The combined results of the last 8 years have led to a better understanding of the history and complexity of Newberry Volcano and improved the design and interpretation of geophysical exploration techniques with regard to blind geothermal resources in volcanic terrain.

15 GEOTHERMAL ENERGY↗

LED Lighting in a Performing Arts Building

At the University of Florida in Gainesville, the DOE Solid-State Lighting GATEWAY program evaluated LED architectural and theatrical lighting in four academic/performance-related spaces within the Nadine McGuire Theatre + Dance Pavilion. Due to a wise choice of products and luminaire light distributions, the change brought significant quality improvements including improved controllability and color.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Comparison of electron beam and laser beam powder bed fusion additive manufacturing process for high temperature turbine component materials

The evolving 3D printer technology is now at the point where some turbine components could be additive manufactured (AM) for both development and production purposes. However, this will require a significant evaluation program to qualify the process and components to meet current design and quality standards. The goal of the project was to begin characterization of the microstructure and mechanical properties of Nickel Alloy X (Ni-22Cr-18Fe-9Mo) test bars fabricated by powder bed fusion (PBF) AM processes that use either an electron beam (EB) or laser beam (LB) power source. The AM materials produced with the EB and LB processes displayed significant differences in microstructure and resultant mechanical properties. Accordingly, during the design analysis of AM turbine components, the specific mechanical behavior of the material produced with the selected AM process should be considered. Comparison of the mechanical properties of both the EB and LB materials to those of conventionally processed Nickel Alloy X materials indicates the subject AM materials are viable alternatives for manufacture of some turbine components.

36 MATERIALS SCIENCE↗

Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Rooftop Air Conditioners

The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-Global Warming Potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants relative to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in packaged or Rooftop Unit (RTU) air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerants selection process, the test procedures, and the final results.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

The Status and Promise of Advanced M&V: An Overview of “M&V 2.0” Methods, Tools, and Applications

Advanced measurement and verification (M&V) of energy efficiency savings, often referred to as M&V 2.0 or advanced M&V, is currently an object of much industry attention. Thus far, however, there has been a lack of clarity about what techniques M&V 2.0 includes, how those techniques differ from traditional approaches, what the key considerations are for their use, and what value propositions M&V 2.0 presents to different stakeholders. The objective of this paper is to provide background information and frame key discussion points related to advanced M&V. The paper identifies the benefits, methods, and requirements of advanced M&V and outlines key technical issues for applying these methods. It presents an overview of the distinguishing elements of M&V 2.0 tools and of how the industry is addressing needs for tool testing, consistency, and standardization, and it identifies opportunities for collaboration. In this paper, we consider two key features of M&V 2.0: (1) automated analytics that can provide ongoing, near-real-time savings estimates, and (2) increased data granularity in terms of frequency, volume, or end-use detail. Greater data granularity for large numbers of customers, such as that derived from comprehensive implementation of advanced metering infrastructure (AMI) systems, leads to very large data volumes. This drives interest in automated processing systems. It is worth noting, however, that automated processing can provide value even when applied to less granular data, such as monthly consumption data series. Likewise, more granular data, such as interval or end-use data, delivers value with or without automated processing, provided the processing is manageable. But it is the combination of greater data detail with automated processing that offers the greatest opportunity for value. Using M&V methods that capture load shapes together with automated processing1 can determine savings in near-real time to provide stakeholders with more timely and detailed information. This information can be used to inform ongoing building operations, provide early input on energy efficiency program design, or assess the impact of efficiency by location and time of day. Stakeholders who can make use of such information include regulators, energy efficiency program administrators, program evaluators, contractors and aggregators, building owners, the investment community, and grid planners. Although each stakeholder has its own priorities and challenges related to savings measurement and verification, the potential exists for all to draw from a single set of efficiency valuation data. Such an integrated approach could provide a base consistency across stakeholder uses.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Low Global Warming Potential Refrigerants for Commercial Refrigeration Systems

Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Environmental concerns are driving regulations for the heating, ventilating, air-conditioning and refrigeration (HVAC&R) industry towards lower GWP alternatives to HFC refrigerants. Existing lower GWP refrigerant alternatives include hydrocarbons, such as propane (R-290) and isobutane (R-600a), as well as carbon dioxide (R-744), ammonia (R-717), and R-32. In addition, new lower GWP refrigerant alternatives are currently being developed by refrigerant manufacturers, including hydrofluoro-olefin (HFO) and unsaturated hydrochlorofluorocarbon (HCFO) refrigerants. The selection of an appropriate refrigerant for a given refrigeration application should be based on several factors, including the GWP of the refrigerant, the energy consumption of the refrigeration system over its operating lifetime, and leakage of refrigerant over the system lifetime. For example, focusing on energy efficiency alone may overlook the significant environmental impact of refrigerant leakage; while focusing on GWP alone might result in lower efficiency systems that result in higher indirect impact over the equipment lifetime. Thus, the objective of this Collaborative Research and Development Agreement (CRADA) between Honeywell and the Oak Ridge National Laboratory (ORNL) is to develop a Life Cycle Climate Performance (LCCP) modeling tool for optimally designing HVAC&R equipment with lower life cycle greenhouse gas emissions, and the selection of alternative working fluids that reduce the greenhouse gas emissions of HVAC&R equipment. In addition, an experimental evaluation program is used to measure the coefficient of performance (COP) and refrigerating capacity of various refrigerant candidates, which have differing GWP values, in commercial refrigeration equipment. Through a cooperative effort between industry and government, alternative working fluids will be chosen based on maximum reduction in greenhouse gases at minimal cost impact to the consumer. This project will ultimately result in advancing the goals of reducing greenhouse gas emissions through the use of low GWP working fluids and technologies for HVAC&R and appliance equipment, resulting in cost-competitive products and systems.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗