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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 1,711 records · Page 95
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Role of Mg:Al ratio and Pt promotion on mitigating the deactivation of Ni-based methane steam reforming catalysts

Ni-based catalysts for CH 4 steam reforming require fine-tuning to withstand deactivation under dynamic operation conditions relevant to emerging H 2 -driven technologies. This study investigates the impact of the Mg:Al ratio and Pt presence in catalyst composition on the activity and stability of industrially relevant Ni-based mono- and bimetallic catalysts during simulated daily start-up and shut-down cycles in various gas atmospheres. The evolution of the catalyst structure during extensive testing procedures was investigated in detail by complementary electron microscopy, in situ/operando XAS and XRD. The results obtained revealed that catalyst deactivation is promoted at high Mg:Al ratios and especially affects the monometallic catalysts. By converting CH 4 at lower temperatures, Pt regulates the extent of Ni oxidation and its incorporation into MgO lattice. Further prevention of catalyst deactivation was achieved by optimizing the reactor shut-down procedure to minimize the simultaneous exposure to high temperatures and H 2 O vapors. By flushing the reactor with N 2 only around the reaction extinction temperature, a fraction of Ni species is maintained in metallic state, which is beneficial for the long-term activity and reaction operation economy.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Technologies and policies to decarbonize global industry: Review and assessment of mitigation drivers through 2070

Fully decarbonizing global industry is essential to achieving climate stabilization, and reaching net zero greenhouse gas emissions by 2050–2070 is necessary to limit global warming to 2 °C. This paper assembles and evaluates technical and policy interventions, both on the supply side and on the demand side. It identifies measures that, employed together, can achieve net zero industrial emissions in the required timeframe. Key supply-side technologies include energy efficiency (especially at the system level), carbon capture, electrification, and zero-carbon hydrogen as a heat source and chemical feedstock. There are also promising technologies specific to each of the three top-emitting industries: cement, iron & steel, and chemicals & plastics. These include cement admixtures and alternative chemistries, several technological routes for zero-carbon steelmaking, and novel chemical catalysts and separation technologies. Crucial demand-side approaches include material-efficient design, reductions in material waste, substituting low-carbon for high-carbon materials, and circular economy interventions (such as improving product longevity, reusability, ease of refurbishment, and recyclability). Strategic, well-designed policy can accelerate innovation and provide incentives for technology deployment. High-value policies include carbon pricing with border adjustments or other price signals; robust government support for research, development, and deployment; and energy efficiency or emissions standards. These core policies should be supported by labeling and government procurement of low-carbon products, data collection and disclosure requirements, and recycling incentives. In implementing these policies, care must be taken to ensure a just transition for displaced workers and affected communities. Similarly, decarbonization must complement the human and economic development of low- and middle-income countries.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

County-level assessment of behind-the-meter solar and storage to mitigate long duration power interruptions for residential customers

Customer concerns over electric system resilience could drive early adoption of behind-the-meter solar-plus-storage (BTM PVESS), especially as wildfire, hurricane, and other climate-driven risks to electric grids become more pronounced. However, the resilience benefits of BTM PVESS are poorly understood, especially for residential customers, owing to lack of data and methodological challenges, making it difficult to forecast adoption trends. In this paper, we develop a methodology to model the performance of BTM PVESS in providing backup power across a wide range of customer types, geography / climate conditions, and long duration power interruption scenarios, considering both whole-building backup and backup of specific critical loads. We combine novel, disaggregated end-use load profiles across the continental United States with temporally and geospatially aligned solar generation estimates. We then implement a PVESS dispatch algorithm to calculate the amount of load served during interruptions. We find that PVESS with 10 kWh of storage can meet a limited set of critical loads in most United States counties during any month of the year, though this capability drops to meeting only 86% of critical load, averaged across all counties and months, when heating and cooling are considered critical. Backup performance is lowest in winter months where electric heat is common (southeast and northwest U.S.) and in summer months in places with large cooling loads (southwest and southeast U.S.). Winter backup performance varies by roughly 20% depending on infiltration rates, while summer performance varies by close to 15% depending on the efficiency of the central air-conditioning system. Differences in temperature set-points in Harris County correspond to a 40% range in winter backup performance and a 20% range in summer performance. Economic calculations show that a customer’s resilience value of PVESS must be high to motivate adoption of these systems.

14 SOLAR ENERGY↗
DOE OSTI2011

Repair pathways independent of the Fanconi anemia nuclear core complex play a predominant role in mitigating formaldehyde-induced DNA damage

The role of the Fanconi anemia (FA) repair pathway for DNA damage induced by formaldehyde was examined in the work described here. The following cell types were used: mouse embryonic fibroblast cell lines FANCA{sup -/-}, FANCC{sup -/-}, FANCA{sup -/-}C{sup -/-}, FANCD2{sup -/-} and their parental cells, the Chinese hamster cell lines FANCD1 mutant (mt), FANCGmt, their revertant cells, and the corresponding wild-type (wt) cells. Cell survival rates were determined with colony formation assays after formaldehyde treatment. DNA double strand breaks (DSBs) were detected with an immunocytochemical {gamma}H2AX-staining assay. Although the sensitivity of FANCA{sup -/-}, FANCC{sup -/-} and FANCA{sup -/-}C{sup -/-} cells to formaldehyde was comparable to that of proficient cells, FANCD1mt, FANCGmt and FANCD2{sup -/-} cells were more sensitive to formaldehyde than the corresponding proficient cells. It was found that homologous recombination (HR) repair was induced by formaldehyde. In addition, {gamma}H2AX foci in FANCD1mt cells persisted for longer times than in FANCD1wt cells. These findings suggest that formaldehyde-induced DSBs are repaired by HR through the FA repair pathway which is independent of the FA nuclear core complex. -- Research highlights: {yields} We examined to clarify the repair pathways of formaldehyde-induced DNA damage. Formaldehyde induces DNA double strand breaks (DSBs). {yields} DSBs are repaired through the Fanconi anemia (FA) repair pathway. {yields} This pathway is independent of the FA nuclear core complex. {yields} We also found that homologous recombination repair was induced by formaldehyde.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Radiation-induced nitric oxide mitigates tumor hypoxia and radioresistance in a murine SCCVII tumor model

Highlights: •IR-induced NO increased tissue perfusion and pO{sub 2}. •IR increased NO production in tumors without changes in the mRNA and protein levels of NOS isoforms. •NOS activity assay showed that IR upregulated eNOS activity in tumors. •IR-induced NO decreased tumor hypoxia and altered tumor radiosensitivity. -- Abstract: Tumor hypoxia, which occurs mainly as a result of inadequate tissue perfusion in solid tumors, is a well-known challenge for successful radiotherapy. Recent evidence suggests that ionizing radiation (IR) upregulates nitric oxide (NO) production and that IR-induced NO has the potential to increase intratumoral circulation. However, the kinetics of NO production and the responsible isoforms for NO synthase in tumors exposed to IR remain unclear. In this study, we aimed to elucidate the mechanism by which IR stimulates NO production in tumors and the effect of IR-induced NO on tumor radiosensitivity. Hoechst33342 perfusion assay and electron spin resonance oxymetry showed that IR increased tissue perfusion and pO{sub 2} in tumor tissue. Immunohistochemical analysis using two different hypoxic probes showed that IR decreased hypoxic regions in tumors; treatment with a nitric oxide synthase (NOS) inhibitor, L-NAME, abrogated the effects of IR. Moreover, IR increased endothelial NOS (eNOS) activity without affecting its mRNA or protein expression levels in SCCVII-transplanted tumors. Tumor growth delay assay showed that L-NAME decreased the anti-tumor effect of fractionated radiation (10 Gy × 2). These results suggested that IR increased eNOS activity and subsequent tissue perfusion in tumors. Increases in intratumoral circulation simultaneously decreased tumor hypoxia. As a result, IR-induced NO increased tumor radiosensitivity. Our study provides a new insight into the NO-dependent mechanism for efficient fractionated radiotherapy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

MicroRNA-187-3p mitigates non-small cell lung cancer (NSCLC) development through down-regulation of BCL6

Hsa-microRNA-187-3p (miR-187-3p) has recently been discovered having anticancer efficacy in different organs. However, the role of miR-187-3p on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-187-3p on the development of NSCLC. The results indicated that miR-187-3p was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-187-3p in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay and colony formation assay, through inhibition of BCL6. In addition, miR-187-3p induced apoptosis, as indicated by concomitantly with up-regulation of the activities of caspase-3 and caspase-7, and inhibited cellular migration and invasiveness through inhibition of BCL6. Further, oncogene BCL6 was revealed to be a putative target of miR-187-3p, which was inversely correlated with miR-187-3p expression in NSCLC. Taken together, our results demonstrated that miR-187-3p played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic BCL6.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Telmisartan mitigates hyperglycemia-induced vascular inflammation by increasing GSK3β-Ser{sup 9} phosphorylation in endothelial cells and mouse aortas

Telmisartan, an angiotensin II type 1 receptor blocker (ARB), attenuates hyperglycemia-aggravated vascular inflammation by decreasing IκB kinase β (IKKβ) expression in endothelial cells. Because glycogen synthase 3β (GSK3β) is involved in inflammatory process by regulating nuclear factor-κB (NF-κB) activity, we investigated whether GSK3β mediates telmisartan-ameliorated vascular inflammation in hyperglycemia-treated endothelial cells and high-fat diet (HFD)-fed mice. Telmisartan remarkably induced GSK3β-Ser{sup 9} phosphorylation in hyperglycemia-treated endothelial cells that accompanied a decrease in hyperglycemia-induced NF-κB p65-Ser{sup 536} phosphorylation, vascular cell adhesion molecule-1 (VCAM-1) expression, and THP-1 monocyte adhesion. Ectopic expression of GSK3β-S9A, a constitutively active mutant of GSK3β, significantly restored complete telmisartan-inhibited NF-κB p65-Ser{sup 536} phosphorylation, VCAM-1 expression, and THP-1 monocyte adhesion. In addition, it reversed telmisartan-repressed IKKβ expression. Among the ARB, including losartan and fimasartan, only telmisartan increased GSK3β-Ser{sup 9} phosphorylation, and telmisartan-induced GSK3β-Ser{sup 9} phosphorylation remained unchanged by pretreatment with GW9662, a specific and irreversible peroxisome proliferator-activated receptor γ (PPARγ) antagonist. Finally, in the aortas of HFD-fed mice, telmisartan treatment significantly attenuated HFD-induced upregulation of NF-κB p65-Ser{sup 536} phosphorylation, VCAM-1 expression, and IKKβ expression and downregulation of GSK3β-Ser{sup 9} phosphorylation. Taken together, our findings demonstrated that telmisartan ameliorates hyperglycemia-exacerbated vascular inflammation, at least in part, by inducing GSK3β-Ser{sup 9} phosphorylation, which consequently inhibits IKKβ expression, NF-κB p65-Ser{sup 536} phosphorylation, and VCAM-1 expression in a PPARγ-independent manner. - Highlights: • Telmisartan inhibits GSK3β activity by inducing GSK3β-Ser{sup 9} phosphorylation. • Increased GSK3β-Ser{sup 9} phosphorylation leads to a decrease in IKKβ expression. • Reduced IKKβ expression attenuates NF-κB p65 phosphorylation and VCAM-1 expression. • Finally, these mediate ameliorating effects of telmisartan on vascular inflammation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MicroRNA-29a mitigation of toll-like receptor 2 and 4 signaling and alleviation of obstructive jaundice-induced fibrosis in mice

Highlights: • miR-29a overexpression in cholestatic mice obstructed TLR2 and TLR4 signaling in liver tissues. • miR-29a overexpression in cholestatic mice decreased IL-1β, MCP-1, TGF-β, TNF-α, as well as HMGB1, and BRD4 expression. • Overexpression of miR-29a downregulated α-SMA, TLR2, TLR4 and BRD4 expression in HSCs. Cholestasis and hepatitis can cause continuous liver damage that may ultimately result in liver fibrosis. In a previous study, we demonstrated that microRNA-29a (miR-29a) protects against liver fibrosis. Toll-like receptor 2 (TLR2) and TLR4 are pattern recognition receptors of bacterial lipoprotein and lipopolysaccharide, both of which participate in activating hepatic stellate cells and liver fibrosis. The purpose of this study is to characterize the biological influence of miR-29a on TLR2 and TLR4 signaling in livers injured with bile duct ligation (BDL). We performed BDL on both miR-29a transgenic mice (miR-29aTg) and wild-type mice to induce cholestatic liver injury. Primary HSCs were transfected with a miR-29a mimic and inhibitor. In the wild-type mice, the BDL demonstrated significant α-smooth muscle actin fibrotic matrix formation and hepatic high mobility group box-1 expression. However, in the miR-29aTg mice, these factors were significantly reduced. Furthermore, miR-29a overexpression reduced the BDL exaggeration of TLR2, TLR4, MyD88, bromodomain-containing protein 4 (BRD4), phospho-p65 as well as proinflammatory cytokines, IL-1β, MCP-1, TGF-β, and TNF-α. In vitro, miR-29a mimic transfection reduced α-SMA, BRD4,TLR2, and TLR4 expressions in HSCs. This study provides new molecular insight into the ability of miR-29a to inhibit TLR2 and TLR4 signaling, which thus slows the progression of cholestatic liver deterioration.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Effects of AI-2 quorum sensing inhibitors on mitigating bacterial contamination in bioethanol production

Here, in this paper, the activities of signal molecule AI-2 in the sole fermentation of Lactiplantibacillus plantarum and co-fermentation of Saccharomyces cerevisiae and L. plantarum were investigated. Co-fermentation of S. cerevisiae and L. plantarum was found to reduce L. plantarum to secrete AI-2. Three AI-2 quorum sensing inhibitors (DMHF (2,5-Dimethyl-4-hydroxy-3-(2H)-furanone), D-Rib ( D -Ribose), and D-Gal ( D -Galactosamine)) were added to the co-fermentation system to further interrupt the growth of L. plantarum. It was found that 0.2 g/L DMHF or 18.0 g/L D-Gal could mainly decrease the activity of AI-2 by 38 % and 36 %, respectively, and significantly inhibit the biofilm formation of L. plantarum. Moreover, the ethanol concentrations of the co-fermentation trials added with 0.2 g/L DMHF or 18.0 g/L D-Gal were 14 % and 103 % higher than that of the control, respectively, within 30 h of fermentation. This study provides basic data for the novel prevention of L. plantarum contamination in bioethanol production via quorum sensing control, which is meaningful for the environmental protection and the sustainable development of bioethanol industry.

09 BIOMASS FUELS↗
DOE OSTI2022

Tradeoffs among indoor air quality, financial costs, and CO 2 emissions for HVAC operation strategies to mitigate indoor virus in U.S. office buildings

Adapting building operation during the COVID-19 pandemic to improve indoor air quality (IAQ) while ensuring sustainable solutions in terms of costs and CO 2 emissions is challenging and limited in literature. Our previous study investigated different HVAC operation strategies, including increased filtration using MERV 10, MERV 13, or HEPA filters, as well as supplying 100% outdoor air into buildings for a system initially sized for MERV 10 filtration. This paper significantly extends that research by systematically analyzing the potential financial and environmental impact for different locations in the U.S. The previous medium office building system model is improved to account for operation in different climates. New evaluation metrics are created to consider the comprehensive impact of improving IAQ on costs and CO 2 emissions, using dynamic emission factors for electricity generation depending on the location. HVAC operation strategies are studied in five different locations across the United States, with distinct climates and electricity sources. In four of the five locations, MERV 13 filtration offers the best improvement in IAQ per increase in costs and emissions relative to MERV 10. The exception is the mildest climate of San Diego, where use of 100% outdoor air provides the best IAQ with a limited increase in costs and emissions. Finally, a system not sized for HEPA filtration can lead to increased costs and emissions without much improvement in IAQ.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Benefits assessment of cool skin and ventilated cavity skin: Saving energy and mitigating heat and grid stress

This study assessed the energy-saving and climate-adaptive potential of cool skin and ventilated cavity skin facade technologies in Seoul's high-rise apartment buildings. We created weather scenarios for historical, mid-term future, and long-term future conditions using Coordinated Regional Downscaling EXperiment (CORDEX) method. Building energy simulations were conducted on a South Korean high-rise apartment model to evaluate their performance under different weather conditions. The results indicate that cool skin and ventilated cavity skin technologies can save cooling energy during summers but lead to heating energy penalties in winters. Ventilated cavity skin outperforms cool skin, offering better cooling energy savings and reduced heating penalties. Combining both technologies yields the highest overall energy savings, with 7 %, 9 %, and 10 % cooling energy savings for cool skin, ventilated cavity skin, and the combined package, respectively. However, cool skin increases heating energy consumption by 5 %, while ventilated cavity skin has minimal impact on heating energy. These envelope technologies also reduce peak electricity demand by at least 5 %, 8 %, and 9 %, respectively. They contribute to heat stress reduction, enhance resilience, and decrease extreme heat risks for occupants during power outages by at least 18 % under various weather conditions. Considering the prevalence of aging high-rise apartments in South Korea, adopting these envelope renovation strategies can effectively reduce cooling loads, enhance thermal comfort, and boost resilience under future climates, while avoiding costly reconstruction.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗