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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Aging-associated stem/progenitor cell dysfunction in the salivary glands of mice

Highlights: • The function of CD133-positive cells changes with age and is expected to be one of the causative factors associated with salivary gland aging. Although stem cell aging leads to a decline in tissue homeostasis and regenerative capacity, it remains unclear whether salivary gland stem cell function changes during this process. However, the salivary glands are gradually replaced by connective tissue during aging. Here, we show a decline in the stem cell ability of CD133-positive stem/progenitor cells in the salivary glands of aged mice. The CD133-positive cells were isolated from young, adult, and aged mice. The number of CD133-positive cells was significantly decreased in aged mice. They also showed a lower sphere formation capacity compared to young and adult mice. RNA sequencing revealed that CD133-positive cells in aged mice exhibited lower gene expression of several aging-related genes, including FoxO3a, than those in young and adult mice. Salivary gland cells infected with a recombinant lentivirus encoding the FoxO3a gene showed a reduction in oxidative stress induced by hydrogen peroxide compared with those infected with a control virus. Thus, FoxO3a may inhibit stem cell aging via oxidative stress.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Investigation of SiO x anode fading mechanism with limited capacity cycling

Silicon suboxide (SiO x ) is one of the promising anode materials for the next-generation lithium-ion batteries. However, SiO x has a severe capacity fading problem during cycling. It is thus desired to investigate the detailed fading mechanisms of SiO x anode materials. In this study, limited capacity cycling was employed to examine the electrochemical behaviors of the SiO x anode, and the lithiation/delithiation cycling was limited within a range of 10% theoretical capacity. This strategy minimizes the volume variation of SiO x materials upon charging/discharging, which helps to reveal their decay factors other than volume fluctuation. It is demonstrated that the instability of the SiO x surface during cycling was likely a parallel factor of active material fading, which seems to cause unfavored electrode interface rearrangements with lowered electric conductivity.

electric vehicles↗
DOE OSTI2021

Comparative Molecular and Immunoregulatory Analysis of Extracellular Vesicles from Candida albicans and Candida auris

Candida auris is a recently described multidrug-resistant pathogenic fungus that is increasingly responsible for health care-associated outbreaks across the world. Bloodstream infections of this fungus cause death in up to 70% of cases. Aggravating this scenario, the disease-promoting mechanisms of C. auris are poorly understood. Fungi release extracellular vesicles (EVs) that carry a broad range of molecules, including proteins, lipids, carbohydrates, pigments, and RNA, many of which are virulence factors. Here, we carried out a comparative molecular characterization of C. auris and Candida albicans EVs and evaluated their capacity to modulate effector mechanisms of host immune defense. Using proteomics, lipidomics, and transcriptomics, we found that C. auris released EVs with payloads that were significantly different from those of EVs released by C. albicans. EVs released by C. auris potentiated the adhesion of this yeast to an epithelial cell monolayer, while EVs from C. albicans had no effect. C. albicans EVs primed macrophages for enhanced intracellular yeast killing, whereas C. auris EVs promoted survival of the fungal cells. Moreover, EVs from both C. auris and C. albicans induced the activation of bone marrow-derived dendritic cells. Together, our findings show distinct profiles and properties of EVs released by C. auris and by C. albicans and highlight the potential contribution of C. auris EVs to the pathogenesis of this emerging pathogen.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Abstract for CRADA between NETL and the AZ Board of Regents on behalf of Arizona State University

Arizona State University (ASU) and the National Energy Technology Laboratory (NETL) will collaborate on the development and scale up of sorbent composites that efficiently capture carbon dioxide (CO 2 ) directly from air under an awarded project from the Department of Energy’s Direct Air Capture (DAC) Pre-Commercialization Technology Prize. For DAC to be considered a viable technology for decarbonization, the cost of carbon removal needs to decrease below the proposed carbon tax incentive outlined in the recent Inflation Reduction Act (IRA) (Section 45 Q), which is set at $\$$180 per ton of CO 2 . Achieving this goal requires the development of a cost-effective, environmentally friendly sorbent with high CO 2 sorption capacity and efficient kinetics under DAC conditions as the overall cost of CO 2 captured is highly sensitive to factors such as sorbent cost and sorbent lifetime. ASU has developed a sorbent technology that can potentially reduce CO 2 removal costs by DAC. NETL has expertise in DAC TEA and LCA development and DAC sorbent testing. The collaboration between ASU and NETL aims to accelerate development and deployment of ASU’s technology by quantifying the performance, cost and lifecycle impacts of ASU’s technology and validating sorbent performance.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Evaluation of overtime phenotypic variation of yeasts in chronic vulvovaginal candidosis cases

Abstract Chronic vulvovaginal candidosis results either from reinfection or from the ability of Candida spp. to persist in the vulva and/or vagina. Persistence is usually associated with increased antifungal (mainly azoles) resistance rates, which can explain treatment failure, and/or increased expression of virulence factors by Candida spp. The aim of this study was to assess the mechanisms leading to Candida spp persistence, by studying sequential isolates from women with chronic vulvovaginal candidosis, focusing on strains genotypes, azole resistance, and ability to form biofilms along the period of clinical evaluation. The strains were identified at species level by automated analysis of biochemical profiles and molecular typing evaluated by polymorphic DNA analysis. The capacity to form biofilm was assessed with a microtiter plate assay. Fluconazole susceptibility was determined by the microdilution broth assay at both pH 7 (following the recommended guideline) and pH 4.5 (as representative of vaginal pH). We studied samples from 17 clinically recurrent cases. In 53% of the chronic cases there were two or more isolates that had a phylogenetic relationship while the remaining (47%) were caused by different species. In those cases where related strains were involved in recurrence, we verified an increase in MIC at pH 7 and also an increased capacity to form biofilms over time. Significant correlation between these two parameters was observed only in cases caused by C. glabrata, evidencing the importance of these two factors to enhance persistence in the vaginal mucosa for this particular species.

Faria-Gonçalves, Paula↗
DOE OSTI2022

Evaluation of Load Behavior for Select Analytes in Hanford Tank Waste

Crystalline silicotitanate (CST) inorganic ion exchanger is a candidate material for remediation of highly alkaline (pH > 14) aqueous nuclear waste streams containing high sodium concentrations (>5 M). In this work, ion exchange column testing with wastes from Hanford tanks AP-105, AP-107, and AW-102 was carried out to study the uptake of 137 Cs to estimate the decontamination factor (DF) value. Additionally, DF values for uptake of Al, Ca, Pb, Np, Pu, U, and Sr were determined and the ion exchange capacity of CST toward these analytes was estimated. Limited data is available on the load behavior of other minor and trace elements with recent CST production lots and this characterization will help improve understanding of the behavior of CST and assist in identifying potential disposition pathways as well as assessing removal capabilities of CST for other components.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Microbe-Encapsulated Silica Gel Biosorbents for Selective Extraction of Scandium from Coal Byproducts

Establishing an inexpensive and environmentally friendly scandium (Sc) supply is critical for the development of clean energy technologies. However, refining Sc from Sc-bearing sources using current technologies poses economic and environmental challenges due to its low concentration relative to base metals and chemically similar lanthanides. In this work, we developed a biosorption-based flow-through process for extraction of Sc from low-grade feedstocks. A novel biosorbent material was synthesized by encapsulating Arthrobacter nicotianae, a bacterium that selectively adsorbs Sc, within a porous silica matrix. Through the use of several complementary microscopy techniques, we demonstrated a highly porous biosorbent structure with a high cell-loading density and a homogenous cell distribution. Batch adsorption assays revealed selective Sc adsorption over lanthanides and common based metals, with the exception of Fe(III), as evidenced by separation factors greater than 50. The MESG particles were packed into fixed-bed columns to enable adsorption under flow-through conditions, which demonstrated effective Sc extraction at flow rates up to 0.08 cm/s and high stability for reuse; greater than 95% of the adsorption capacity was maintained after 10 consecutive adsorption/desorption cycles. When applied to a lignite coal leachate, whose Fe content was depleted through pH-mediated precipitation, the MESG particles yielded Sc breakthrough at 30 bed volumes, whereas all other metals broke through after only a few bed volumes. Following desorption, an eluate with a 124-fold increase in Sc purity was achieved relative to the lignite leachate with Sc constituting 96.4% of the total REEs. This study established a rapid, facile, and scalable cell immobilization approach that enables the use of microbial biomass for Sc recovery from low-grade sources.

Dong, Ziye↗
DOE OSTI2021

Strong influence of convective heat transfer efficiency on the cooling benefits of green roof irrigation

Abstract By enhancing evapotranspiration (ET), green roofs provide cooling benefits for the urban environment and are recognized as a promising heat mitigation strategy. The evaporative cooling effects of green roofs strongly depend on the soil moisture conditions and thus irrigation may be needed to sustain the cooling benefits. It has been shown that the magnitude of cooling benefits offered by green roof irrigation varies spatially, but its controlling factors remain elusive. In this study, we combine a surface energy balance (SEB) model with global simulations generated by an improved Earth System Model to illustrate the key factors controlling the cooling benefits of green roof irrigation. We employ a simple irrigation scheme, which is only active when there is no ice in soil layers and when the soil moisture is below field capacity. As a result, most of the irrigation water leaves the green roof system via ET. We find that the magnitude and also the spatial variability of the cooling benefits of green roof irrigation are controlled by the irrigation amount, and a surface energy redistribution factor that encodes the efficiencies of different SEB components in transferring heat. Further analysis indicates that the enhancement of latent heat flux due to irrigation is largely balanced by the reduction of sensible heat flux on green roofs. Therefore, the amount of irrigation needed per unit decrease of green roof surface temperature is mainly controlled by the convective heat transfer efficiency. A lower convective heat transfer efficiency (e.g. under a lower wind speed) helps reduce the amount of irrigation needed per unit decrease of green roof surface temperature. This study highlights the importance of SEB in constraining the cooling benefits of green roof irrigation and provides valuable guidance for urban planners and policy makers in terms of heat mitigation and sustainable water management.

Wang, Linying (ORCID:0000000308769220)↗
DOE OSTI2021

Masking of photovoltaic system performance problems by inverter clipping and other design and operational practices

We describe how performance problems can be “masked,” or not readily evident by several causes: by photovoltaic (PV) system configuration (such as the size of the PV array capacity relative to the size of the inverter and the resultant clipped operating mode); by instrumentation design, installation, and maintenance (such as a misaligned or dirty pyranometer); by contract clauses (when operational availability is transformed to contractual availability, which excludes many factors); and by identified management and operational practices (such as reporting on a portfolio of plants rather than individually). A simple method based on a duration curve is introduced to overcome shortcomings of Performance Ratio based on nameplate capacity and Performance Index based on hourly simulation when quantifying masking effects, and inverter clipping and pyranometer soiling are presented as two examples of the new method. With a better understanding of the non-transparency of masking issues, stakeholders can better interpret performance data and deliver improved AC and DC plant conditions through PV system operation and maintenance (O&M) for improved performance, reduced O&M costs, and a more consistently delivered, and reduced, levelized cost of energy (LCOE).

14 SOLAR ENERGY↗
DOE OSTI2026

High‑performance cold‑climate heat pump using tandem compressors with and without vapor injection: Laboratory investigation and field demonstration

Cold‑climate air‑source heat pumps must maintain heating capacity and stable operation at low ambient temperatures for residential applications. This study adapts tandem single-speed compressors—proven in commercial systems —for residential CCHPs, integrating VI and validating performance across laboratory and extreme field conditions to achieve cold-climate targets. That is to achieve ≥75% of the rated heating capacity at −25.0 °C relative to 8.3 °C and heating coefficient of performance (COP) greater than 4.0 at 8.3 °C. Laboratory testing confirmed that both configurations met these targets while operating within acceptable discharge‑temperature limits. Relative to the non‑VI configuration, the VI system provided up to 15% higher heating capacity and up to 9% higher heating COP under identical conditions, yielding a 5.6–9.1% increase in heating seasonal performance factor (HSPF). Field tests in Ohio and Alaska, with minimum outdoor temperatures of −25.0 °C and −34.0 °C, respectively, showed stable operation, minimal supplemental heating (<3.2%), low defrost penalties, and consistent output. Tandem‑compressor architectures proves promising for cold-climate residential heating.

Hu, Yifeng [ORNL] (ORCID:0000000242875185)↗
DOE OSTI2021

Simulation of Hurricane Harvey flood event through coupled hydrologic-hydraulic models: Challenges and next steps

Using the 2017 Hurricane Harvey flood event as a test case, this study set up a series of sensitivity analyses to highlight three challenges associated with large-scale flood inundation modeling, including (a) model parameterization, (b) errors in digital elevation models, and (c) effects of reservoir retention. Driven by radar-based hourly rainfall data, a series of hydrologic-hydraulic models including the VIC hydrologic model, RAPID routing model, and Flood2D-GPU hydrodynamic model are set up over Harris County, Texas, to simulate flood inundation and hazards. The results demonstrate the importance of hydrologic parameters in improving flood modeling. For a large flood event such as Hurricane Harvey, the effect of the initial water depths is insignificant. The Manning's n values may increase the peak water depth by ~1%, the flood extents by 65km 2 , and the high danger zone by ~6%. On the contrary, the bathymetry correction factors may reduce the flood extent by ~1.4% and the high-danger zone by ~4%. Reducing the reservoir storage capacity to 1% may increase the flood extent by ~4% and the high-danger zone by ~17%. This study may provide supporting information to guide and prioritize the development of future high-performance computing hydrodynamic large-scale flood simulations.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Evaluating the Grid Impact of Oregon Offshore Wind

This analysis used high resolution offshore wind data and a detailed production cost model of the Western Interconnection to explore the value and operational impact of integrating offshore wind along Oregon's coastline. Leveraging local technical stakeholder expertise and input, we determined a set of scenarios to explore. These scenarios varied offshore wind penetrations and explored the differences of integrating offshore wind in the current grid and a potential future grid. This allowed us to determine how changes to the rest of the system and increasing penetrations of offshore wind affected our findings. We identified a number of key findings from the analysis, including that 2.6 GW of nameplate capacity offshore wind could be integrated into the Oregon power system with minimal curtailment due to transmission congestion or other factors. The range of system value provided by offshore wind ranges between $\$$65/MWh and $\$$85/MWh across the various scenarios considered. We also examined the influence offshore wind had on the trans-Cascade power flow, where we determined a strong correlation between offshore wind generation and reduction in flow across the Cascades. Finally, we also determined that offshore wind could serve between 84 - 93% of Coastal Oregon loads depending on the scenario.

17 WIND ENERGY↗
DOE OSTI2023

CRISPR/Cas9 Directed Reprogramming of iPSC for Accelerated Motor Neuron Differentiation Leads to Dysregulation of Neuronal Fate Patterning and Function

Neurodegeneration causes a significant disease burden and there are few therapeutic interventions available for reversing or slowing the disease progression. Induced pluripotent stem cells (iPSCs) hold significant potential since they are sourced from adult tissue and have the capacity to be differentiated into numerous cell lineages, including motor neurons. This differentiation process traditionally relies on cell lineage patterning factors to be supplied in the differentiation media. Genetic engineering of iPSC with the introduction of recombinant master regulators of motor neuron (MN) differentiation has the potential to shorten and streamline cell developmental programs. We have established stable iPSC cell lines with transient induction of exogenous LHX3 and ISL1 from the Tet-activator regulatory region and have demonstrated that induction of the transgenes is not sufficient for the development of mature MNs in the absence of neuron patterning factors. Comparative global transcriptome analysis of MN development from native and Lhx-ISL1 modified iPSC cultures demonstrated that the genetic manipulation helped to streamline the neuronal patterning process. However, leaky gene expression of the exogenous MN master regulators in iPSC resulted in the premature activation of genetic pathways characteristic of the mature MN function. Dysregulation of metabolic and regulatory pathways within the developmental process affected the MN electrophysiological responses.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Assessing concurrent effects of climate change on hydropower supply, electricity demand, and greenhouse gas emissions in the Upper Yangtze River Basin of China

Hydropower importantly provides flexible low-carbon electricity, however, climate change will affect the hydropower system through altering hydrologic regimes while also affecting electricity demands for heating and cooling that hydropower resources serve. This study assesses the effect of climate change on hydropower and electricity demand in the Upper Yangtze River Basin (UYRB) in China on the regional net electric load and greenhouse gas (GHG) emissions. This is accomplished by using climate projections from five global climate models (GCMs) to simultaneously force (1) a physically-based hydrological model and a statistically-based hydropower model to estimate the future generating capacity of 21 large hydropower plants in the UYRB and (2) an empirical electricity demand model accounting for socioeconomic and climatic factors. Under climate change, the projected hydropower generation in the UYRB tends to increase in the 21st century but is far less than the increase in electricity demand, increasing the gap between demand and supply. Future increases in overall electricity demand are driven by GDP growth, but climate change will alter the distribution of the seasonal electricity demand. Climate warming decreases electricity demand for heating in winter and increases electricity demand for cooling in summer, but ultimately increases demand. Meanwhile, there is an increasing mismatch between electricity demand and hydropower supply associated with inter- and intra-annual variations, owing to the temporal climate change and increase in compound climate extremes (droughts and heatwaves). Finally, meeting the gap between supply and demand due to climate change is estimated to contribute 79.0–184.6 and 50.6–316.2 MMT CO 2e /yr of additional GHG emissions by the mid and end of 21st century, respectively.

13 HYDRO ENERGY↗
DOE OSTI2021

Interactions of Wind Energy Project Siting, Wind Resource Potential, and the Evolution of the U.S. Power System

The interactions of wind energy project siting, resource potential, and power system evolution are critical to understand given interest in high renewable energy systems, particularly as wind costs have fallen and grid operators implement solutions to manage variable generation. This study applies an integrative approach that combines spatially-explicit resource potential analysis with high spatial resolution U.S. electricity system modeling. Multiple wind supply curves, representing variations in siting regimes that account for interactions with built infrastructure, regulatory, physical, and social land use factors, are evaluated to determine how siting could influence prospective wind development. Different siting regimes lead to variations in future wind capacity, with the greatest impacts observed under scenarios with high demand for clean energy. With the tightest emissions limit modeled, 2050 onshore wind capacity varied by +7% (49 GW) in the least-restrictive siting regime to a decrease of 37% (270 GW) under the most-constrained case. More-stringent siting restrictions lead to higher electricity prices and emissions that should be weighed with local impacts. Under restrictive siting regimes, wind deployment is also sensitive to transmission availability and wind plant design. Overall, the findings highlight the importance of local land use considerations in regional and national power system planning.

17 WIND ENERGY↗
DOE OSTI2022

Viewing convection as a solar farm phenomenon broadens modern power predictions for solar photovoltaics

We report heat mitigation for large-scale solar photovoltaic (PV) arrays is crucial to extend lifetime and energy harvesting capacity. PV module temperature is dependent on site-specific farm geometry, yet common predictions consider panel-scale and environmental factors only. Here, we characterize convective cooling in diverse PV array designs, capturing combined effects of spatial and atmospheric variation on panel temperature and production. Parameters, including row spacing, panel inclination, module height, and wind velocity, are explored through wind tunnel experiments, high-resolution numerical simulations, and operating field data. A length scale based on fractal lacunarity encapsulates all aspects of arrangement (angle, height, etc.) in a single value. When applied to the Reynolds number Re within the canonical Nusselt number heat transfer correlation, lacunarity reveals a relationship between convection and farm-specific geometry. This correlation can be applied to existing and forthcoming array designs to optimize convective cooling, ultimately increasing production and PV cell life.

14 SOLAR ENERGY↗
DOE OSTI2021

Lead tolerance and bioremoval by four strains of green algae from Nigerian fish ponds

Heavy metals from industry pose threats to human and environmental health. Microalgae are prime candidates to remove heavy metals from water and soil due to their metal-binding affinities, high growth rates, and contamination tolerance. Strain selection and composition of resulting contaminated biomass must be considered for downstream processing. In this study, we assessed the ability of four microalgae strains (Chlorophyceae) that were isolated from contaminated Nigerian fish ponds to take up dissolved lead at environmentally relevant concentrations (<0.05 mg L -1 – WHO standard). In a microplate assay, all strains grew in the presence of lead, tolerating concentrations up to 60 ppm, though the addition of dissolved lead affected the growth of the four strains. In a photobioreactor assay, all strains demonstrated the ability to take up dissolved lead, with removal efficiencies ranging from 86 to 93%. The concentrations of lead in contaminated biomass, removal efficiencies, and bioconcentration factors were greatest in one of the isolates Chlorella sp. MOW 12. Our results reinforce the fact that live microalgae have a greater biosorption capacity. Lead recovery from freeze-dried biomass using five different reagents showed that a 0.1 M hydrochloric acid solution was the most effective, with 83.4% recovery. We also showed that presence of lead in the culture medium resulted in an increase in the quantity of protein in the biomass. Elemental analysis of lead-bound biomass showed an increase in elements including boron and copper and a decrease in cobalt and sodium. Synergystic and antagonystic effect in uptake of other elements was strain specific, suggesting the possibility of tailored wastewater treatments depending on specific requirements.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2026

Characterizing peak electricity demand for U.S. households: an assessment of end-use loads and demand factors

Understanding household peak electricity demand is critical to evaluate the technical need for electrical infrastructure upgrades. This study characterizes peak loads for existing and new equipment using metered data from a convenience sample of 11,940 U.S. dwellings from four sources, including 911 from two sources with end-use metering. After standardized data cleaning and labeling, we derived descriptive statistics for key metrics, such as maximum demand and demand factors, and developed predictive models relating 60- to 15-min demand for the National Electrical Code (NEC). Mean 15-min maximum demand was 9.7 kW (median 9.0 kW; IQR 7.0–11.5 kW, 95% CI 9.6–9.8 kW), indicating spare capacity in 98% of homes with hypothetical 100 A panels. Maximum demand increased with floor area and number of high-demand loads. Dwelling maximum demand was driven by higher-power, longer-duration heating appliances and vehicle charging, while most user-operated appliances contributed little. Demand factors are used to account for how most devices contribute less than their rated power to maximum demand. Existing load mean demand factors (28%; median 10%; IQR 0–58%; CI 28–29%) were higher than those for new loads (21%; median 7%; IQR 0–35%; CI 20–21%), because new loads changed the timing and magnitude of maximum demand. New high-demand loads had higher than average demand factors (40–60%). Whole dwelling demand factors support the NEC's 40% assumption, but they challenge its conservative 100% treatment of new HVAC. We propose a data-driven 50% demand factor for new equipment, which would align with metered data, improve affordability, and modernize electrical codes.

Appliances↗