Exploratory study of the 180 m Ta ( γ , γ ' ) 180 Ta reaction with mono-energetic low-energy photon beams at HI γ S
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Instruments & Instrumentation↗
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Results for “Exploratory Study”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Internet of things and Big Data as potential solutions to the problems in waste electrical and electronic equipment management: An exploratory study
Highlights: • Major problems in current WEEE management have been identified. • Communication technologies enabling smart WEEE management are described. • Framework of implementing the IoT and the Big Data technologies is proposed. • Application scenarios based on real-world cases are constructed and discussed. • Challenges as well as future research opportunities are identified. - Abstract: Management of Waste Electrical and Electronic Equipment (WEEE) is a vital part in solid waste management, there are still some difficult issues require attentionss. This paper investigates the potential of applying Internet of Things (IoT) and Big Data as the solutions to the WEEE management problems. The massive data generated during the production, consumption and disposal of Electrical and Electronic Equipment (EEE) fits the characteristics of Big Data. Through using the state-of-the-art communication technologies, the IoT derives the WEEE “Big Data” from the life cycle of EEE, and the Big Data technologies process the WEEE “Big Data” for supporting decision making in WEEE management. The framework of implementing the IoT and the Big Data technologies is proposed, with its multiple layers are illustrated. Case studies with the potential application scenarios of the framework are presented and discussed. As an unprecedented exploration, the combined application of the IoT and the Big Data technologies in WEEE management brings a series of opportunities as well as new challenges. This study provides insights and visions for stakeholders in solving the WEEE management problems under the context of IoT and Big Data.
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
Exploratory study reveals far reaching systemic and cellular effects of verapamil treatment in subjects with type 1 diabetes
Currently, no oral medications are available for type 1 diabetes (T1D). While our recent randomized placebo-controlled T1D trial revealed that oral verapamil had short-term beneficial effects, their duration and underlying mechanisms remained elusive. Now, our global T1D serum proteomics analysis identified chromogranin A (CHGA), a T1D-autoantigen, as the top protein altered by verapamil and as a potential therapeutic marker and revealed that verapamil normalizes serum CHGA levels and reverses T1D-induced elevations in circulating proinflammatory T-follicular-helper cell markers. RNA-sequencing further confirmed that verapamil regulates the thioredoxin system and promotes an anti-oxidative, anti-apoptotic and immunomodulatory gene expression profile in human islets. Moreover, continuous use of oral verapamil delayed T1D progression, promoted endogenous beta-cell function and lowered insulin requirements and serum CHGA levels for at least 2 years and these benefits were lost upon discontinuation. Thus, the current studies provide crucial mechanistic and clinical insight into the beneficial effects of verapamil in T1D.
60 APPLIED LIFE SCIENCES↗
Preventing leaching from lead water pipes with electrochemistry: an exploratory study
Toxic levels of lead leaching from ageing water distribution infrastructure affect over 5000 public drinking water systems in the US. Pipe replacement, the most effective solution to this problem, is prohibitively expensive. Additionally, chemical conditioning of drinking water using orthophosphates, although cost-effective, does not quickly stop lead leaching once it has started. We propose a novel approach to stop lead leaching: to rapidly form an insoluble scale within lead pipes using an external power supply. We report on the feasibility of this approach by first anodizing lead coupons and lead pipes reclaimed from a local water distribution using a phosphate electrolyte and different potentials, pH values, and phosphate concentrations. We subsequently exposed these anodized lead coupons and pipes to synthetic tap water to evaluate their lead leaching rates. We found that polarizing lead coupons in the presence of a 0.05 M phosphate solution decreased lead leaching by up to a 100-fold, relative to leaching from polished bare lead. Similarly, polarizing the reclaimed lead pipes (with a preexisting scale) decreased lead leaching from an average of 36 ppb to 7 ppb. These results were observed when applying potentials that favor Pb(IV) formation, which resulted in the buildup of PbO 2 and Pb 5 (PO 4 ) 3 OH in both lead coupons and pipes. Our findings indicate that this novel technology has the potential to rapidly decrease equilibrium lead levels in tap water below the EPA action limit of 15 ppb, and thus deserves further exploration.
54 ENVIRONMENTAL SCIENCES↗
Exploratory studies into 3 d /4 f cluster formation with fully bridge-substituted calix[4]arenes
Calix[4]arenes are extremely versatile ligands that are capable of supporting the formation of a wide variety of polymetallic clusters of paramagnetic metal ions. One can exert influence over cluster formation through alteration of the calix[4]arene framework and subsequent ‘expansion’ of the lower-rim polyphenolic binding site. The present contribution investigates cluster formation with calix[4]arenes substituted at all four methylene bridge positions with furan moieties. Finally, two known cluster types have been isolated with this ligand, the structures of which lend insight into factors that may ultimately preclude the formation of mixed-metal species.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Exploratory study of fission product yields of neutron-induced fission of U 235 , U 238 , and Pu 239 at 8.9 MeV
Using dual-fission chambers each loaded with a thick (200–400–mg/cm 2 ) actinide target of 235,238 U or 239 Pu and two thin (~10–100–μg/cm 2 ) reference foils of the same actinide, the cumulative yields of fission products ranging from 92 Sr to 147 Nd have been measured at E n = 8.9MeV. The 2 H(d,n) 3 He reaction provided the quasimonoenergetic neutron beam. Here, the experimental setup and methods used to determine the fission product yield (FPY) are described, and results for typically eight high-yield fission products are presented.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Gauge dependence of the quark gap equation: An exploratory study
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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Light-Neutrino Exchange and Long-Distance Contributions to 0 ν 2 β Decays: An Exploratory Study on π π → e e
Not Available
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Determinants of the use of alternatives to arsenic-contaminated shallow groundwater: an exploratory study in rural West Bengal, India
Shallow groundwater containing toxic concentrations of arsenic is the primary source of drinking water for millions of households in rural West Bengal, India. Often, this water also contains unpleasant levels of iron and non-negligible fecal contamination. Alternatives to shallow groundwater are increasingly available, including government-built deep tubewells, water purchased from independent providers, municipal piped water, and household filters. We conducted a survey of 501 households in Murshidabad district in 2014 to explore what influenced the use of available alternatives. Socioeconomic status and the perceived likelihood of gastrointestinal (GI) illness (which was associated with dissatisfaction with iron in groundwater) were the primary determinants of the use of alternatives. Arsenic knowledge was limited. The choice amongst alternatives was influenced by economic, social, and aesthetic factors, but not by health risk perceptions. The use of purchased water was rarely exclusive and was strongly associated with socioeconomic status, suggesting that this form of market-based water provision does not ensure universal access. Demand for purchased water appeared to decrease significantly shortly after free piped water became available at public taps. Finally, our results suggest that arsenic mitigation interventions that also address co-occurring water problems (iron, GI illness) could be more effective than a focus on arsenic alone.
54 ENVIRONMENTAL SCIENCES↗
Excavationless Exterior Foundation Insulation Exploratory Study
Building science research supports installing exterior (soil side) foundation insulation as the optimal method to enhance the hygrothermal performance of new homes. With exterior foundation insulation, water management strategies are maximized while insulating the basement space and ensuring a more even temperature at the foundation wall. Controlling for bulk water, vapor, and wall temperature differential reduces the risk of rot and mold formation to insulation and building materials, thereby improving opportunities for structural integrity, indoor air quality, comfort, and energy efficiency. The intent of this study by the NorthernSTAR Building America Partnership team is to search for combinations of existing technologies that could enable a minimally invasive, cost-competitive, easily deployable method of upgrading soil-side foundation insulation in existing buildings. Currently, insulating foundation walls on the exterior side involves exposing the foundation wall using an excavator. Following excavation, these walls can be waterproofed, and are typically insulated with board foam in a process similar to new construction. This process is expensive and highly disruptive to the landscape and the homeowner. Also, barriers such as porches and sidewalks prevent trenching. An ideal approach would involve excavating a very narrow trench directly next to the foundation wall. Full-height foundation wall insulation might be desired, so the trenching technology should be able to dig to a depth of 7 or 8 ft. Because houses often have hardscape obstructions that are expensive to demolish and remove, the ideal technology would be capable of digging under at least some obstructions that would remain in place.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Exploratory study on potential safeguards applications for shared ledger technology
The International Atomic Energy Agency (IAEA) is responsible for providing credible assurance that countries are meeting their obligations not to divert or misuse nuclear materials and facilities for non-peaceful purposes. To this end, the IAEA integrates information about States’ nuclear material inventories and transactions with other types of data to draw its safeguards conclusions. As the amount and variety of data and information has increased, the IAEA’s data acquisition, management, and analysis processes have greatly benefited from advancements in computer science, data management, and cybersecurity during the last 20 years. Despite these advancements, inconsistent use of advanced computer technologies as well as political concerns among certain IAEA Member States centered on trust, transparency, and IAEA authorities limit the overall effectiveness and efficiency of IAEA safeguards. As a result, there is an ongoing need to strengthen the effectiveness and efficiency of IAEA safeguards while improving Member State cooperation and trust in the safeguards system. These chronic safeguards needs could be met with some emerging technologies, specifically those associated with the digital currency bitcoin.
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
“Thought I’d Share First” and Other Conspiracy Theory Tweets from the COVID-19 Infodemic: Exploratory Study
Background: The COVID-19 outbreak has left many people isolated within their homes; these people are turning to social media for news and social connection, which leaves them vulnerable to believing and sharing misinformation. Health-related misinformation threatens adherence to public health messaging, and monitoring its spread on social media is critical to understanding the evolution of ideas that have potentially negative public health impacts. Objective: The aim of this study is to use Twitter data to explore methods to characterize and classify four COVID-19 conspiracy theories and to provide context for each of these conspiracy theories through the first 5 months of the pandemic. Methods: We began with a corpus of COVID-19 tweets (approximately 120 million) spanning late January to early May 2020. We first filtered tweets using regular expressions (n=1.8 million) and used random forest classification models to identify tweets related to four conspiracy theories. Our classified data sets were then used in downstream sentiment analysis and dynamic topic modeling to characterize the linguistic features of COVID-19 conspiracy theories as they evolve over time. Results: Analysis using model-labeled data was beneficial for increasing the proportion of data matching misinformation indicators. Random forest classifier metrics varied across the four conspiracy theories considered (F1 scores between 0.347 and 0.857); this performance increased as the given conspiracy theory was more narrowly defined. We showed that misinformation tweets demonstrate more negative sentiment when compared to non-misinformation tweets and that theories evolve over time, incorporating details from unrelated conspiracy theories as well as real-world events. Conclusions: Although we focus here on health-related misinformation, this combination of approaches is not specific to public health and is valuable for characterizing misinformation in general, which is an important first step in creating targeted messaging to counteract its spread. Initial messaging should aim to preempt generalized misinformation before it becomes widespread, while later messaging will
5g↗
Potential for Applying Continuous Directed Evolution to Plant Enzymes: An Exploratory Study
Plant evolution has produced enzymes that may not be optimal for maximizing yield and quality in today’s agricultural environments and plant biotechnology applications. By improving enzyme performance, it should be possible to alleviate constraints on yield and quality currently imposed by kinetic properties or enzyme instability. Enzymes can be optimized more quickly than naturally possible by applying directed evolution, which entails mutating a target gene in vitro and screening or selecting the mutated gene products for the desired characteristics. Continuous directed evolution is a more efficient and scalable version that accomplishes the mutagenesis and selection steps simultaneously in vivo via error-prone replication of the target gene and coupling of the host cell’s growth rate to the target gene’s function. However, published continuous systems require custom plasmid assembly, and convenient multipurpose platforms are not available. We discuss two systems suitable for continuous directed evolution of enzymes, OrthoRep in Saccharomyces cerevisiae and EvolvR in Escherichia coli, and our pilot efforts to adapt each system for high-throughput plant enzyme engineering. To test our modified systems, we used the thiamin synthesis enzyme THI4, previously identified as a prime candidate for improvement. Our adapted OrthoRep system shows promise for efficient plant enzyme engineering.
59 BASIC BIOLOGICAL SCIENCES↗
Exploratory Studies of Mechanical Properties, Residual Stress, and Grain Evolution at the Local Regions near Pores in Additively Manufactured Metals
Directed energy deposition (DED) is gaining widespread acceptance in various industrial applications since its unique manufacturing features allow the DED to print metallic parts with very complex geometries. However, DED inevitably generates a lot of internal pores which can limit the widespread applications of the DED technique. The current studies on DED porosity are mostly focused on analyzing pores’ bulk-scale influences on mechanical properties and performances. Since DED pores have a micro-scale existence, with dimensions ranging from a few microns to several hundred microns, it is fundamental to explore the pores’ influences on the micro-scale, including local mechanical properties, residual stress, and grains near pores. However, this important research direction has been neglected. The objective of this work is to fill the above gap in DED porosity research and acquire a fundamental understanding of the role of porosity on a microscopic scale. The authors used nanoindentation approaches to investigate internal pores’ effects on mechanical properties and residual stress in local regions surrounding the pores. In addition, the grains near pores were observed through EBSD, and simulated with the Kinetic Monte Carlo model. The research findings can be provided for DED researchers and industrial practitioners as technical guidance. Most importantly, the research results can work as a good reference for tracing the source of bulk-scale mechanical performances and properties of DED parts with internal pores.
36 MATERIALS SCIENCE↗
The Role of Federal Libraries and Federal Librarians in Research Data Services: An Exploratory Study
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cyberinfrastructure↗
Exploratory Pu(III) Oxalate/Pu(IV) Oxide Morphology Studies
Exploratory experiments were performed to see if morphological information (particle- size/habit) about PuO 2 might give useful information about growth conditions for its oxalate precursor. We performed experiments with trivalent Pu and its analogue, trivalent cerium (Ce). Movies of the Ce oxalate experiments showed that solution turbidities can be a useful monitor for the precipitation kinetics. It was clear that when mixing was too slow to keep up with oxalic acid addition, precipitates formed locally, and partially re-dissolved when oxalic addition was complete. The Ce oxalate and oxide particle-sizes determined in liquid slurries by traditional light-scattering instrumentation agreed in general with those found by SEM imaging. The Ce oxalate size distributions depended on the synthesis conditions, but it was not monotonic in the progression from best- to worst-mixed. Uniformity, as measured by the FWHM (full width at half maximum) of the distributions, varied by a factor of two or more. Because the distributions and FWHMs did not change monotonically as synthesis conditions changed from best- to worst-mixed, the utility of the size distributions for Ce as a diagnostic is doubtful.
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
Wind turbine main bearing rating lives as determined by IEC 61400‐1 and ISO 281: A critical review and exploratory case study
Abstract This paper studies the rating lives of wind turbine main bearings, as determined by the IEC 61400‐1 and ISO 281 standards. A critical review of relevant bearing life theory and turbine design requirements is provided, including discussion on possible shortcomings such as the existence (or not) of the bearing fatigue load limit and the validity of assuming linear damage accumulation. A detailed exploratory case study is then undertaken to determine rating lives for two models of main bearing in a 1.5 MW wind turbine. Rating life assessment is carried out under different conditions, including various combinations of main bearing temperature, wind field characteristics, lubricant viscosity, and contamination levels. Rating lives are found to be sufficiently above the desired 20‐year design life for both bearing models under expected operating conditions. For the larger bearing, operational loads are shown to be below or close to the bearing fatigue load limit a vast majority of the time. Key sensitivities for rating life values are temperature and contamination. Overall, the results of this study suggest that an ISO 281 rating life assessment does not account for reported rates of main bearing failures in 1 to 3 MW wind turbines. It is recommended that a similar analysis be undertaken for ISO/TS 16281 rating lives, along with further efforts to identify principal root causes of main bearing failures in future work, possibly leading to a new application standard specific to this component. It is also recommended that the impacts of partial wake impingement on main bearing rating lives are investigated.
17 WIND ENERGY↗