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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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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Solving the Grid Optimization Competition Challenge 3 Problem

The Grid Optimization Competition Challenge 3 Problem posed a multiperiod security-constrained unit commitment problem with base-case AC power flow. The problem formulation includes binary unit commitment decisions, nonlinear AC power flow and balance, dispatchable loads, and linearized contingency real power flow, among other features. This talk will present a modified consensus ADMM algorithm, which splits the problem into mixed-integer linear and nonlinear components, as a heuristic solution method for this large-scale mixed integer nonlinear program. We will present some computational results from the competition for our implementation and reflect on the challenges of participating the grid optimization competition.

AC power flow↗
DOE OSTI2023

Co-occurrence of native white-tailed deer and invasive wild pigs: Evidence for competition?

Understanding whether invasive and native species compete for shared resources where they co-occur is essential for mitigating the negative impacts of invasive species on native ecosystems. Here, we examined how the presence and density of an invasive species, wild pigs (Sus scrofa), affect native white-tailed deer (Odocoileus virginianus; hereafter, deer) on the Savannah River Site, SC, USA. We examined potential changes in deer areas of use, temporal overlap, and occupancy to evaluate the effects of wild pig occurrence and density on deer space use, diel activity, and co-occurrence with wild pigs across 9 months during 2018 and 2019. Wild pig density had the strongest effect on deer space use in high- and moderate-use areas. Declines in deer space use in response to wild pig density were most pronounced in March and October 2018 and April 2019 for females, while male space use declined in response to wild pig density in October and December 2018. Both species were largely nocturnal with high overlap in diel activity across months. Deer occupancy responses to wild pig density varied across months, with negative responses in May and October 2018 and positive responses in July 2018 and April 2019. Deer and wild pigs co-occurred at 30%–59% of camera stations across months, with broadscale co-occurrence patterns being unaffected by changes in shared cover or wild pig occurrence. Overall, our results suggest that deer make fine-scale behavioral adjustments to avoid wild pigs, providing evidence that competition is likely occurring even where wild pig density is relatively low. Such fine-scale behavioral plasticity in deer appears to mitigate the costs of competition with wild pigs and may be a mechanism enabling long-term co-existence of deer and wild pigs. Our study provides novel insight on the complexities of spatiotemporal relationships between invasive wild pigs and native deer and suggests that the negative effects of interactions between deer and wild pigs may be more pronounced when deer life history needs are particularly demanding. In areas where eradication of invasive wild pigs may be impossible, maintaining low wild pig densities may help mitigate, but may not eliminate, the negative effects of wild pigs on deer.

resource partitioning↗
DOE OSTI2016

Effect of biofilm coatings at metal-oxide/water interfaces II: Competitive sorption between Pb(II) and Zn(II) at Shewanella oneidensis /metal-oxide/water interfaces

Competitive sorption of Pb(II) and Zn(II) on Shewanella oneidensis MR-1 biofilm-coated single-crystal α-Al 2 O 3 (1 –1 0 2) and α-Fe 2 O 3 (0 0 0 1) surfaces was investigated using long-period X-ray standing wave-florescence yield (LP-XSW-FY) spectroscopy. In situ partitioning of aqueous Pb(II) and Zn(II) between the biofilms and underlying metal-oxide substrates was probed following exposure of these complex interfaces to equi-molar Pb and Zn solutions (0.01 M NaNO 3 as background electrolyte, pH = 6.0, and 3-h equilibration time). At higher Pb and Zn concentrations (≥10 –5 M), more than 99% of these ions partitioned into the biofilms at S. oneidensis /α-Al 2 O 3 (1 –1 0 2)/water interfaces, which is consistent with the partitioning behavior of both Pb(II) or Zn(II) in single-metal-ion experiments. Furthermore, no apparent competitive effects were found in this system at these relatively high metal-ion concentrations. However, at lower equi-molar concentrations (≤10 –6 M), Pb(II) and Zn(II) partitioning in the same system changed significantly compared to the single-metal-ion systems. The presence of Zn(II) decreased Pb(II) partitioning onto α-Al 2 O 3 (1 –1 0 2) substantially (~52% to ~13% at 10 –7 M, and ~23% to ~5% at 10–6 M), whereas the presence of Pb(II) caused more Zn(II) to partition onto α-Al 2 O 3 (1 –1 0 2) surfaces (~15% to ~28% at 10 –7 M, and ~1% to ~7% at 10 –6 M) .The higher observed partitioning of Zn(II) (~28%) at the α-Al 2 O 3 (1 –1 0 2) surfaces compared to Pb(II) (~13%) in the mixed-metal-ion systems at the lowest concentration (10 –7 M) suggests that Zn(II) is slightly favored over Pb(II) for sorption sites on α-Al 2 O 3 (1 –1 0 2) surfaces under our experimental conditions.

58 GEOSCIENCES↗
DOE OSTI2021

An evaluation of electricity system technology competitiveness metrics: The case for profitability

In this work we develop standardized functional forms for electricity technology competitiveness metrics and show how the mathematical relationship between value and cost can affect the robustness of the metric. Here, we make the case to replace established metrics with economic profitability metrics – including a new profitability-based adjustment to LCOE. These profitability metrics are shown to be more robust for evaluating technology competitiveness by keeping comparisons on an equivalent monetary basis.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Impedance-Based Detection of NO 2 Using Ni-MOF-74: Influence of Competitive Gas Adsorption

Chemically robust, low-power sensors are needed for the direct electrical detection of toxic gases. Metal–organic frameworks (MOFs) offer exceptional chemical and structural tunability to meet this challenge, though further understanding is needed regarding how coadsorbed gases influence or interfere with the electrical response. To probe the influence of competitive gases on trace NO 2 detection in a simulated flue gas stream, a combined structure–property study integrating synchrotron powder diffraction and pair distribution function analyses was undertaken, to elucidate how structural changes associated with gas binding inside Ni-MOF-74 pores correlate with the electrical response from Ni-MOF-74-based sensors. Data were evaluated for 16 gas combinations of N 2 , NO 2 , SO 2 , CO 2 , and H 2 O at 50 °C. Fourier difference maps from a rigid-body Rietveld analysis showed that additional electron density localized around the Ni-MOF-74 lattice correlated with large decreases in Ni-MOF-74 film resistance of up to a factor of 6 × 10 3 , observed only when NO 2 was present. These changes in resistance were significantly amplified by the presence of competing gases, except for CO 2 . Without NO 2 , H 2 O rapidly (<120 s) produced small (1–3×) decreases in resistance, though this effect could be differentiated from the slower adsorption of NO 2 by the evaluation of the MOF’s capacitance. Furthermore, samples exposed to H 2 O displayed a significant shift in lattice parameters toward a larger lattice and more diffuse charge density in the MOF pore. Evaluating the Ni-MOF-74 impedance in real time, NO 2 adsorption was associated with two electrically distinct processes, the faster of which was inhibited by competitive adsorption of CO 2 . Together, this work points to the unique interaction of NO 2 and other specific gases (e.g., H 2 O, SO 2 ) with the MOF’s surface, leading to orders of magnitude decrease in MOF resistance and enhanced NO2 detection. Finally, understanding and leveraging these coadsorbed gases will further improve the gas detection properties of MOF materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Competitive exclusion by autologous antibodies can prevent broad HIV-1 antibodies from arising

Significance Broadly neutralizing antibodies against HIV have recently been discovered, but their highly mutated nature and late emergence in infection make it difficult to infer how they arose. As a step to understanding their development, we investigate antibody–virus coevolution, using a mathematical model. Here we find that broadly neutralizing antibodies in principle may arise earlier and be less mutated, but that competition between broad responses and initial autologous antibody responses delays their emergence. It may be possible to reduce this competition and elicit broadly neutralizing antibodies earlier than previously thought by using a vaccine with diverse viral strains.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Neutron-$\gamma$ competition for β-delayed neutron emission

Here we present a coupled quasiparticle random phase approximation and Hauser-Feshbach (QRPA+HF) model for calculating delayed particle emission. This approach uses microscopic nuclear structure information, which starts with Gamow-Teller strength distributions in the daughter nucleus and then follows the statistical decay until the initial available excitation energy is exhausted. Explicitly included at each particle emission stage is γ-ray competition. We explore this model in the context of neutron emission of neutron-rich nuclei and find that neutron-γ competition can lead to both increases and decreases in neutron emission probabilities, depending on the system considered. Finally, a second consequence of this formalism is a prediction of more neutrons on average being emitted after β decay for nuclei near the neutron drip line compared to models that do not consider the statistical decay.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

Competitive Electricity Market Regulation in the United States: A Primer

The electricity system in the United States is a complex mechanism where different technologies, jurisdictions and regulatory designs interact. Today, two major models for electricity commercialization operate in the United States. One is the regulated monopoly model, in which vertically integrated electricity providers are regulated by state commissions. The other is the competitive model, in which power producers can openly access transmission infrastructure and participate in wholesale electricity markets. This paper describes the origins, evolution, and current status of the regulations that enable competitive markets in the United States.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2017

U.S. Clean Energy Hydrogen and Fuel Cell Technologies: A Competitiveness Analysis

The objectives of this project are a 1) Global Competitiveness Analysis of hydrogen and fuel cell systems and components manufactured including 700 bar compressed hydrogen storage system in the U.S., Europe, Asia, and other key areas to be identified to determine the global cost leaders, the best current manufacturing processes, the key factors determining competitiveness, and the potential means of cost reductions; and an 2) Analysis to assess the status of global hydrogen and fuel cell markets. The analysis of units, megawatts by country and by application will focus on polymer electrolyte membrane (PEM) fuel cell systems (automotive and stationary).

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Writing Competitive Proposals [Slides]

A proposal is a written response to an opportunity offered by a funding organization. Proposals must meet a SOLICITOR’S needs, not YOUR needs. A solicited proposal is a written response to a specific solicitation issued by a sponsor. These solicitations are typically called RFPs, or Requests for Proposals. RFPs are specific in their requirements regarding format and technical content. Scientists at Los Alamos often deal with this type of proposal — Laboratory-Directed Research and Development (LDRD) proposals are one example. An unsolicited proposal is one submitted to a sponsor who has not issued a specific solicitation. It usually comes about during interactions at meetings or conferences. In some instances, a sponsor may be visiting for another reason when the possibility for an unsolicited proposal becomes available. A pre-proposal is one in which a sponsor wishes to gage competition before having participants prepare a formal, full-length proposal. These types of scenarios imply that the actual proposal could be highly competitive and will usually be by invitation only.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2026

U.S. Department of Energy Solar District Cup Collegiate Design Competition

The Solar District Cup is a multidisciplinary collegiate competition that challenges student teams to design and model standalone solar and solar-plus-storage systems for multiple buildings on a local electrical distribution network, such as a college campus, across a development, or in a district. Students learn cross-cutting skills that prepare them to become part of the next generation of the distributed energy workforce. Student teams act as renewable energy developers proposing to solar and solar-plus-storage system requests. Students, faculty, and prospective employers can benefit from knowing about this program and what students learn--either immediately as participants, mentors, or judges, or as potential employers of Solar District Cup alumni. RE+ is also one of our competition partners.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2016

Genetic manipulation of competition for nitrate between heterotrophic bacteria and diatoms

Diatoms are a dominant group of eukaryotic phytoplankton that contribute substantially to global primary production and the cycling of important elements such as carbon and nitrogen. Heterotrophic bacteria, including members of the gammaproteobacteria, are commonly associated with diatom populations and may rely on them for organic carbon while potentially competing with them for other essential nutrients. Considering that bacterioplankton drive oceanic release of CO 2 (i.e., bacterial respiration) while diatoms drive ocean carbon sequestration vial the biological pump, the outcome of such competition could influence the direction and magnitude of carbon flux in the upper ocean. Nitrate availability is commonly a determining factor for the growth of diatom populations, particularly in coastal and upwelling regions. Diatoms as well as many bacterial species can utilize nitrate, however the ability of bacteria to compete for nitrate may be hindered by carbon limitation. Here we have developed a genetically tractable model system using the pennate diatom Phaeodactylurn tricomuturn and the widespread heterotrophic bacteria Alterornonas macleodii to examine carbon-nitrogen dynamics. While subsisting solely on P. tricomutum derived carbon. A. macleodii does not appear to be an effective competitor for nitrate, and may in fact benefit the diatom; particularly in stationary phase. However, allochthonous dissolved organic carbon addition in the form of pyruvate triggers A. macleodii proliferation and nitrate uptake, leading to reduced P. tricornutum growth. Nitrate reductase deficient mutants of A. macleodii ( ΔnasA ) do not exhibit such explosive growth and associated competitive ability in response to allochthonous carbon when nitrate is the sole nitrogen source, but could survive by utilizing solely P. tricomutum -derived nitrogen. Furthermore, allocthonous carbon addition enables wild-type A. macleodii to rescue nitrate reductase deficient P. tricomutum populations from nitrogen starvation, and RNA-seq transcriptomic evidence supports nitrogen-based interactions between diatoms and bacteria at the molecular level. As a result, this study provides key insights into the roles of carbon and nitrogen in phytoplankton-bacteria dynamics and lays the foundation for developing a mechanistic understanding of these interactions using co-culturing and genetic manipulation.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Peeling back the many layers of competitive exclusion

Baby chicks administered a fecal transplant from adult chickens are resistant to Salmonella colonization by competitive exclusion. A two-pronged approach was used to investigate the mechanism of this process. First, Salmonella response to an exclusive (Salmonella competitive exclusion product, Aviguard ® ) or permissive microbial community (chicken cecal contents from colonized birds containing 7.85 Log 10 Salmonella genomes/gram) was assessed ex vivo using a S. typhimurium reporter strain with fluorescent YFP and CFP gene fusions to rrn and hilA operon, respectively. Second, cecal transcriptome analysis was used to assess the cecal communities’ response to Salmonella in chickens with low (≤5.85 Log 10 genomes/g) or high (≥6.00 Log 10 genomes/g) Salmonella colonization. The ex vivo experiment revealed a reduction in Salmonella growth and hilA expression following co-culture with the exclusive community. The exclusive community also repressed Salmonella’s SPI-1 virulence genes and LPS modification, while the anti-virulence/inflammatory gene avrA was upregulated. Salmonella transcriptome analysis revealed significant metabolic disparities in Salmonella grown with the two different communities. Propanediol utilization and vitamin B12 synthesis were central to Salmonella metabolism co-cultured with either community, and mutations in propanediol and vitamin B12 metabolism altered Salmonella growth in the exclusive community. There were significant differences in the cecal community’s stress response to Salmonella colonization. Cecal community transcripts indicated that antimicrobials were central to the type of stress response detected in the low Salmonella abundance community, suggesting antagonism involved in Salmonella exclusion. This study indicates complex community interactions that modulate Salmonella metabolism and pathogenic behavior and reduce growth through antagonism may be key to exclusion.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Occupant Behavior for Energy Conservation in Commercial Buildings: Lessons Learned from Competition at the Oak Ridge National Laboratory

Accompanying efforts worldwide to deploy sustainable building technologies shows a pressing need for expanded research on occupant behavior. Discourse is lacking concerning drivers of occupant behavior for energy conservation, especially in the case of commercial buildings. This paper explores potential determinants of occupant behavior for energy conservation in commercial buildings. This is investigated in a case study of a two-month energy conservation competition involving eight office buildings at the Oak Ridge National Laboratory. Four buildings achieved energy savings based on the previous year’s baseline. Potential challenges and success factors of occupant behavior for energy conservation during the competition were explored based on an explanatory research design incorporating energy data, participant interviews, and surveys. The findings suggest that both social and technological aspects may be important drivers of energy conservation. The determinants of occupant behavior for energy conservation in commercial buildings suggested for further research include bottom-up involvement, stakeholder relationship management, targeted information, real-time energy visualization, and mobile social platforms. This paper presents initial implications, with a need for further research on these propositions and on their impacts on occupant behavior. This paper aims to contribute to both academia and practitioners in the arena of commercial building sustainability.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2014

DOE Collegiate Wind Competition (Presentation)

This presentation for the January Stakeholder Engagement and Outreach webinar outlines the expanded need for workers in the wind industry and provides an overview of the DOE Wind Competition (to be held in May 2014) and the guiding principles of the competition.

17 WIND ENERGY↗
DOE OSTI2016

Energy by the Numbers: Collegiate Wind Competition

The U.S. Department of Energy Collegiate Wind Competition prepares students from multiple disciplines to enter tomorrow’s wind energy workforce. As part of the competition, undergraduate students build and test a wind turbine, establish a deployment strategy, and develop and deliver a business plan.

17 WIND ENERGY↗
DOE OSTI2017

Turbines, Wind Tunnels, and Teamwork: The 2017 Collegiate Wind Competition Technical Challenge

Ten college teams put their turbines to the test at the U.S. Department of Energy’s 2017 Collegiate Wind Competition Technical Challenge, held April 20–22 at the National Wind Technology Center (NWTC). The competition showcased a wide variety of turbine designs and highlighted the competitors’ brilliance, agility, and ingenuity. College students weren’t the only future wind energy experts at the NWTC that weekend: elementary and middle school students tested their turbines—crafted creatively from materials like soda bottles and aluminum foil—in the Colorado KidWind Challenge.

17 WIND ENERGY↗
DOE OSTI2019

Brookhaven Co-Hosts 2018 U.S. DOE CyberForce Competition

In December 2018, five college teams came to Brookhaven Lab to participate in the CyberForce Competition, an annual U.S. Department of Energy (DOE)-sponsored nationwide cyberdefense competition in which students defend a simulated energy infrastructure network from cyberattack. They competed against more than 50 teams hosted by six other national labs.

97 MATHEMATICS AND COMPUTING↗