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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 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Activation of neuregulin-4 in adipocytes improves metabolic health by enhancing adipose tissue angiogenesis

Highlights: • Targeted activation of Nrg4 in adipocytes enhanced adipose tissue angiogenesis. • Activation of Nrg4 in adipocytes improved systemic metabolic health. • Angiogenesis inhibition abolished the beneficial effects of Nrg4 on metabolic health. • Inhibition of ErbB signaling in EC abrogated the Nrg4-mediated angiogenesis. • ErbB signal inhibition canceled the beneficial effects of Nrg4 on metabolic health. Obesity often causes systemic metabolic disorders in close association with adipose tissue dysfunction. Adipose tissue contains well-developed vasculatures, and obesity mediates vascular rarefaction that causes hypoxia and triggers inflammation in adipose tissue. Adipose tissue-derived neuregulin-4 (Nrg4) is an immerging factor that is critically involved in metabolic homeostasis. We recently identified that Nrg4 is an angiogenic adipokine that plays an important role in maintaining adipose tissue vasculature. Here, we further validated its beneficial role in metabolic health primarily by enhancing adipose tissue angiogenesis. Targeted activation of Nrg4 in adipocytes improved metabolic health in mice under both normal and high fat dietary condition without changes in body weight. Activation of Nrg4 increased blood vessels in white adipose tissue, and ameliorated adipose tissue hypoxia under obese condition. Of note, inhibition of angiogenesis by sugen-treatment abolished the beneficial effects of Nrg4 on systemic metabolic health. Furthermore, targeted inhibition of Nrg4-ErbB signaling in adipose tissue vasculature using prohibitin binding peptide-conjugated nanocarrier abrogated the enhanced adipose tissue angiogenesis, and canceled the improved metabolic health induced by Nrg4 activation. These data further support a crucial role of Nrg4 in maintaining systemic metabolic homeostasis at least partially through enhancing adipose tissue angiogenesis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Simultaneous application of predictive model and least cost formulation can substantially benefit biorefineries outside Corn Belt in United States: A case study in Florida

Previously, a predictive model was developed to identify optimal blends of expensive high-quality and cheaper low-quality feedstocks for a given geographical location that can deliver high sugar yields. Here, the optimal process conditions were tested for application at commercially-relevant higher biomass loadings. We observed lower sugar yields but 100% conversion to ethanol from a blend that contained only 20% high-quality feedstock. The impact of applying this predictive model simultaneously with least cost formulation model for a biorefinery location outside of the US Corn Belt in Lee County, Florida was investigated. A blend ratio of 0.30 EC, 0.45 SG, and 0.25 CS in Lee County was necessary to produce sugars at high yields and ethanol at a capacity of 50 MMGY. This work demonstrates utility in applying predictive model and LCF to reduce feedstock costs and supply chain risks while optimizing for product yields.

09 BIOMASS FUELS↗
DOE OSTI2025

Alpha ketoacid decarboxylases: Diversity, structures, reaction mechanisms, and applications for biomanufacturing of platform chemicals and fuels

In living cells, alpha-ketoacid decarboxylases (KDCs, EC 4.1.1.-) are a class of enzymes that convert alpha-ketoacids into aldehydes through decarboxylation. These aldehydes serve as either drop-in chemicals or precursors for the biosynthesis of alcohols, carboxylic acids, esters, and alkanes. These compounds play crucial roles in cellular metabolism and fitness and the bioeconomy, facilitating the sustainable and renewable biomanufacturing of platform chemicals and fuels. This review explores the diversity and classification of KDCs, detailing their structures, mechanisms, and functions. We highlight recent advancements in repurposing KDCs to enhance their efficiency and robustness for biomanufacturing. Additionally, we present modular KDC-dependent metabolic pathways for the microbial biosynthesis of aldehydes, alcohols, carboxylic acids, esters, and alkanes. Lastly, we discuss recent developments in the modular cell engineering technology that can potentially be applied to harness the diversity of KDC-dependent pathways for biomanufacturing platform chemicals and fuels.

09 BIOMASS FUELS↗
DOE OSTI2025

Kinetic and structural evidence for specific DMSO interference with reversible binding of uncharged bis-oximes to hAChE and their reactivation kinetics of OP-hAChE

The structural basis of inhibitory effect of organic solvent dimethyl sulfoxide (DMSO) on human acetylcholinesterase (EC 3.1.1.7; hAChE) was inferred from the effect of DMSO on kinetics of reversible inhibition of uncharged, heterocyclic bis-oximes to hAChE, from DMSO effect on rates of reactivation of inactive organophosphate (OP)-hAChE conjugates by bis-oximes and by X-ray structures of bis-oxime and DMSO binding to hAChE. Here, the reversible inhibition constant of DMSO for hAChE in 0.1 M phosphate buffer pH 7.4 at 22 °C, was K i = (0.32 ± 0.04) % (or 45 ± 5 mM). The K i of the bis-oxime LG-703 for hAChE was 3.2-fold larger in 1 % DMSO, consistent with direct competition between LG-703 and DMSO. The X-ray structure of the LG-703∗hAChE complex (PDB ID: 6U3P) shows DMSO and LG-703 bound to individual hAChE monomers, LG-703 in the chain A and DMSO in the chain B. In the co-crystallization both small molecules were present at a similar excess over their corresponding K i values for hAChE (7.8-fold for DMSO and 6.5-fold for LG-703) and formation of two different complexes (DMSO∗hAChE and LG-703∗hAChE), in the same crystal, appears consistent with inhibition kinetics. Furthermore, rates of reactivation of paraoxon-inhibited hAChE (POX-hAChE) and of VX-hAChE by LG-703 and by a novel heterocyclic bis-oxime LG-1922 were reduced 2 – 3-fold in DMSO, consistent with observation of the active-center-bound DMSO molecules in the newly solved structure of the LG-1922∗POX-hAChE complex presented here and in our POX-hAChE structure (PDB ID: 8DT2) showing obstruction of the reactivator access to the conjugated P atom.

Acetylcholinesterase inhibition↗
DOE OSTI2017

Persistence behavior of metamifop and its metabolite in rice ecosystem

In this study, a field experiment was conducted to determine the persistence of metamifop in transplanted rice crop for two seasons. Metamifop 10% EC was applied at two doses: 100 g a.i. ha -1 and 200 g a.i. ha -1 at 2–3 leaf stage of Echinochloa crusgalli. The residues of metamifop along with its major metabolite, N-(2-fluorophenyl)-2-hydroxy-N-methylpropionamide (HFMPA), were estimated in rice plant, field water and soil using Liquid Chromatography Mass Spectrometry. Limit of detection and limit of quantification of the method for both the compounds were set at 0.003 μg g -1 and 0.010 μg g -1 respectively. Metamifop showed less persistence in field water and rice plant as compared to soil samples. Presence of HFMPA was recorded in rice plant and soil. Both the compounds were found below level of quantification in harvest samples of straw, grains, husk and soil. Lastly, a safe waiting period of 52 d was suggested for harvesting of rice when metamifop was applied at 100 g a.i. ha -1 (recommended dose).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Laccase-catalyzed α-arylation of benzoylacetonitrile with substituted hydroquinones

This article investigates a green method for α-arylation of a primary nitrile. Compounds possessing a benzylic nitrile have shown to exhibit biological activity. Laccases (benzenediol:oxygen oxidoreductase EC 1.10.3.2) were used as the catalysts to perform the cross-coupling reaction between benzoylacetonitrile and substituted hydroquinones. The corresponding 2-substituted 3-oxo-3-phenylpropanenitriles where synthesized in moderate to excellent yields in pH 7.0 buffered water under mild conditions. The substituent on the hydroquinone had a significant impact on product yields and regioselectivity of reaction. The use of laccases, which require O 2 as their only co-substrate and produce H 2 O as their only by-product, to perform this transformation is an environmentally benign method for α-arylation of primary nitriles.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Deciphering the structure of Arabidopsis thaliana 5-enol-pyruvyl-shikimate-3-phosphate synthase: An essential step toward the discovery of novel inhibitors to supersede glyphosate

Glyphosate interferes with plant aromatic metabolism through the inhibition of 5-enol-pyruvyl-shikimate-3-phosphate (EPSP) synthase [EPSPS, EC 2.5.1.19]. For this reason, EPSPS has been extensively studied in a vast array of organisms. This notwithstanding, up to date, the crystal structure of the protein has been solved exclusively in a few prokaryotes, while that of the plant enzyme has been only deduced in silico by similarity. This study aimed at determining the structure of EPSPS from the plant model species Arabidopsis thaliana, which has been cloned, heterologously expressed and affinity-purified. The kinetic properties of the enzyme have been determined, as well as its susceptibility to the inhibition brought about by glyphosate. The crystal structure of the protein has been resolved at high resolution (1.4 Å), showing open conformation of the enzyme, which is the state ready for substrate/inhibitor binding. This provides a framework for the structure-based design of novel EPSPS inhibitors. Surface regions near the active-site cleft entrance or at the interdomain hinge appear promising for inhibitor selectivity, while bound chloride near the active site is a potential placeholder for anionic moieties of future herbicides.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Performance analysis of absorption thermal energy storage for distributed energy systems

In recent years, distributed energy systems (DES) have attracted worldwide attention. Distributed generation unit (DG) in DES usually works under part load during night, which results in low efficiency and the waste heat of DG cannot be fully utilized. This study proposes a novel absorption thermal energy storage system together with electric energy storage for distributed energy systems. The proposed absorption thermal energy storage system which is a combination of absorption chiller and liquid storage tanks, has a higher energy storage density. During off-peak hours, the extra electricity of DG can be used by electric chillers (EC) and the extra waste heat of DG is stored by the proposed absorption thermal energy storage system. The stored thermal energy is released in peak hours to meet the cooling loads of buildings. A case study of DES in a campus under cooling-dominated climate is conducted to evaluate the performance of the proposed system. The results in a typical summer day indicate that the DG utilization rate increases from 80% to 92.9%, meanwhile the required capacities of electric chillers can be obviously reduced. The operating cost of DES also reduces by 12.9% compared with the DES without energy storage. Through appropriate operation strategy, off-the-grid operation for DES can be achieved without energy waste by applying the proposed energy storage method.

Wang, Lingshi↗
DOE OSTI2015

Determinants of land take at the regional scale: a study concerning Sardinia (Italy)

In its “Roadmap to a Resource Efficient Europe” (Communication COM(2011) 571 of 20 September 2011), the European Commission (EC) established an ambitious goal for the European Union (EU), that of achieving no land take by 2050; towards this aim, a key milestone for the year 2020 was set, by stating that European policies in the programming period 2014–2020 ought to consider both their direct and their indirect impacts on land use in the EU. Within this framework, this paper builds upon the findings of a previous paper (Zoppi and Lai, 2014), in which we estimated the magnitude of land take over a short period of time (2003–2008) in Sardinia, an Italian NUTS2 region, and we assessed whether and how land take is related to a set of variables that are regarded as important determinants in the literature, such as parcel size, accessibility, and proximity to main cities and towns, to the coastline, or to protected areas. In this paper we study the land-taking process taking Sardinia as a case study, in two larger time periods, 1960–1990 and 1990–2008. We assess if, and to what extent, these factors reveal similar, or different, effects in the two periods, and try to identify consistencies concerning the determinants of land take. - Highlights: • Population density and parcel size significantly affect the magnitude of land take. • The presence of nature conservation areas hinders land taking processes. • Extensive urbanization might effectively preserve non-artificial land. • Balanced accessibility of settlements and nature conservation regional policies can effectively contrast land take. • Size of non-artificial land parcels that become artificial is negatively and significantly connected to land take.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Design, synthesis and biological evaluations of N-Hydroxy thienopyrimidine-2,4-diones as inhibitors of HIV reverse transcriptase-associated RNase H

Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) is the only HIV enzymatic function not targeted by current antiviral drugs. Although various chemotypes have been reported to inhibit HIV RNase H, few have shown significant antiviral activities. We report herein the design, synthesis and biological evaluation of a novel N-hydroxy thienopyrimidine-2,3-dione chemotype (11) which potently and selectively inhibited RNase H with considerable potency against HIV-1 in cell culture. Current structure-activity-relationship (SAR) identified analogue 11d as a nanomolar inhibitor of RNase H (IC 50 = 0.04 μM) with decent antiviral potency (EC 50 = 7.4 μM) and no cytotoxicity (CC 50 > 100 μM). In extended biochemical assays compound 11d did not inhibit RT polymerase (pol) while inhibiting integrase strand transfer (INST) with 53 fold lower potency (IC 50 = 2.1 μM) than RNase H inhibition. Furthermore, crystallographic and molecular modeling studies confirmed the RNase H active site binding mode.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

A systematic exploration of boceprevir-based main protease inhibitors as SARS-CoV-2 antivirals

Boceprevir is an HCV NSP3 inhibitor that was explored as a repurposed drug for COVID-19. It inhibits the SARS-CoV-2 main protease (M Pro ) and contains an α-ketoamide warhead, a P1 β-cyclobutylalanyl moiety, a P2 dimethylcyclopropylproline, a P3 tert-butylglycine, and a P4 N-terminal tert-butylcarbamide. By introducing modifications at all four positions, we synthesized 20 boceprevir-based M Pro inhibitors including PF-07321332 and characterized their M Pro inhibition potency in test tubes (in vitro) and 293T cells (in cellulo). Crystal structures of M Pro bound with 10 inhibitors and cytotoxicity and antiviral potency of 4 inhibitors were characterized as well. Replacing the P1 site with a β-(S-2-oxopyrrolidin-3-yl)-alanyl (Opal) residue and the warhead with an aldehyde leads to high in vitro potency. The original moieties at P2, P3 and the P4 N-terminal cap positions in boceprevir are better than other tested chemical moieties for high in vitro potency. In crystal structures, all inhibitors form a covalent adduct with the M Pro active site cysteine. Here, the P1 Opal residue, P2 dimethylcyclopropylproline and P4 N-terminal tert-butylcarbamide make strong hydrophobic interactions with M Pro , explaining high in vitro potency of inhibitors that contain these moieties. A unique observation was made with an inhibitor that contains a P4 N-terminal isovaleramide. In its M Pro complex structure, the P4 N-terminal isovaleramide is tucked deep in a small pocket of M Pro that originally recognizes a P4 alanine side chain in a substrate. Although all inhibitors show high in vitro potency, they have drastically different in cellulo potency to inhibit ectopically expressed M Pro in human 293T cells. In general, inhibitors with a P4 N-terminal carbamide or amide have low in cellulo potency. This trend is reversed when the P4 N-terminal cap is changed to a carbamate. The installation of a P3 O-tert-butyl-threonine improves in cellulo potency. Three molecules that contain a P4 N-terminal carbamate were advanced to cytotoxicity tests on 293T cells and antiviral potency tests on three SARS-CoV-2 variants. They all have relatively low cytotoxicity and high antiviral potency with EC 50 values around 1 μM. A control compound with a nitrile warhead and a P4 N-terminal amide has undetectable antiviral potency. Based on all observations, we conclude that a P4 N-terminal carbamate in a boceprevir derivative is key for high antiviral potency against SARS-CoV-2.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

High voltage LIB cathodes enabled by salt-reinforced liquid electrolytes

We report on electrochemical properties of Li/Li 1.2 Ni 0.15 Co 0.1 Mn 0.55 O 2 secondary batteries in electrolytes designed to stabilize electrodeposition of lithium. Ethylene carbonate (EC): dimethyl carbonate (DMC) containing a LiPF6/LiF salt blend stabilizes lithium electrodeposition and enables Li/Li 1.2 Ni 0.15 Co 0.1 Mn 0.55 O 2 batteries with a high discharge capacity of 270 mAh·g - 1 at 0.05 mA cm - 2 . Cells containing the LiF-reinforced electrolytes also exhibit excellent capacity retention over 500 cycles with Columbic efficiencies approaching 100%. Post-mortem SEM analysis of the lithium anode shows more compact deposition in the presence of the LiF salt additive, while XPS depth profile analysis of cathodes show a more uniform distribution of Mn over the first 180 nm from the electrode/electrolyte interface. The results imply that LiF reinforced electrolytes simultaneously facilitate stable lithium electrodeposition and reduce Mn dissolution.

25 ENERGY STORAGE↗
DOE OSTI2020

Effects of solvent formulations in electrolytes on fast charging of Li-ion cells

Improving the fast charging performance of lithium ion batteries (LIBs) has the promise to increase the widespread adoption of electric vehicles (EVs). Electrolyte development plays an important role in enabling fast charging. In this study, fast charging performance of LIBs is studied with different electrolytes of 1.2 M LiPF 6 in Ethylene Carbonate (EC)/Ethyl Methyl Carbonate (EMC)/co-solvents at 30/50/20 wt%. The co-solvents are methyl acetate (MA), ethyl acetate (EA), ethyl formate (EF), dimethyl carbonate (DMC) and EMC. Long term cycling performance under fast charging shows different capacity retention behaviors for different co-solvents. The structural changes in the electrode material are studied by X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD). The molarity changes in electrolyte is investigated by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The electrode/electrolyte interfaces before and after fast charging are analyzed by X-ray photoemission spectroscopy (XPS). The characterization results are in good agreement with the long-term cycling performance. DMC shows the highest fast-charging capability among the five studied co-solvents due to its increased conductivity, improved electrode/electrolyte interface and stable electrode structural integrity.

25 ENERGY STORAGE↗
DOE OSTI2023

Continuum-Level Modeling of Li-Ion Battery SEI by Upscaling Atomistically Informed Reaction Mechanisms

Understanding and controlling solid-electrolyte interphase (SEI) formation to stabilize cell performance is a significant challenge for next-generation Li-ion battery technologies. In recent years, computational modeling has become an essential tool in providing fundamental insights into SEI properties and dynamics. However, neither atomistic nor continuum-level approaches alone can capture the complexities of SEI chemistry across all relevant length and time scales. In this work, a continuum-level model is developed that is informed by reaction mechanisms obtained from first-principle calculations. The atomistically informed continuum-level model is used to understand electrolyte degradation, including the decomposition of ethylene carbonate (EC), ethyl methyl carbonate (EMC), and fluoroethylene carbonate (FEC). The model presented here is the most chemically complex continuum-level SEI model in the literature to date. The SEI model is calibrated against experimental irreversible leakage currents and shows qualitative agreement with expected SEI growth trends. The model framework is expected to accelerate fundamental understanding of SEI formation, facilitate mechanism development feedback, and dynamically interact with experimental insights.

continuum-level model↗
DOE OSTI2016

Climate Mitigation in Latin America: Implications for Energy and Land Use: Preface to the Special Section on the findings of the CLIMACAP-LAMP Project

The CLIMACAP-LAMP project, completed in December 2015, was an inter-model comparison exercise that focused on energy and climate change economics issues in Latin America. The project partners – co-financed by the EC / EuropeAid (CLIMACAP part) and EPA / USAID (LAMP part) and co-coordinated by respectively the Energy research Centre of the Netherlands (ECN) and the Pacific Northwest National Laboratory (PNNL) – report their main and detailed findings in this Special Issue of Energy Economics, exclusively dedicated to climate mitigation, low-carbon development and implications for energy and land use in Latin America. Our research endeavor included several of the most prominent regional energy modeling groups from Latin America, as well as a representative set of global integrated assessment modeling groups from a number of institutions from Europe and the US. About two dozen universities, research groups and environmental or consulting organizations took part in the CLIMACAP-LAMP cross-model comparison project, from both sides of the Atlantic. Over a handful of workshops were organized over the past four years in several countries in Latin America, attended by between 30 and 50 participants from, amongst others, Argentina, Brazil, Colombia, Mexico, the EU, and the US.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Energy-efficient multimodal mobility networks in transportation digital twins: Strategies and optimization

The study proposes a comprehensive Transportation Mobility (TransitMo) framework covering conceptual design, model formulation, optimization, simulation, and impact analysis of the transportation mobility system. TransitMo is composed of a transportation digital twin developed in Simulation of Urban MObility (SUMO) and an Intelligent Traffic Management and Control Center (ITMCC) that identifies the best ways to improve the movement of people within urban areas using various modes of transportation. This study encompasses advanced modeling techniques, algorithms, and strategic testing to optimize energy efficiency and mobility in a multimodal shared mobility network. TransitMo’s practical applications are exemplified through a city-scaled simulation network in Chattanooga, TN, employing demographic data to analyze historical traffic patterns and forecast future demands. Central to this methodology are three models: the User Preference Model (UP), the Energy Consumption Model (EC), and the System Optimization Model (SO). These models work in concert to iteratively devise the optimal travel incentives and minimize the total system cost in a real-time manner. In conclusion, test results verified that the proposed adaptive incentive program and optimized bus scheduling can improve network performance by increasing public transit ridership.

42 ENGINEERING↗
DOE OSTI2026

Networks of electrochemical oxidation of common lithium-ion Battery solvents revealed by NMR spectroscopy

Raising the upper cutoff voltage of lithium-ion batteries (LIBs) to increase energy density often exceeds the electrolyte’s anodic stability limit, accelerating degradation and creating a major durability tradeoff. Designing electrolytes that can sustain long-term high-voltage cycling requires a clearer understanding of the fundamental mechanisms occurring when commercial carbonate solvents oxidize. Here, to this end, simplified single-salt, single-solvent formulations of LiClO 4 and LiPF 6 in dimethyl carbonate (DMC), ethylene carbonate (EC), or ethyl methyl carbonate (EMC) were anodically electrolyzed on inert electrodes and monitored for extended periods of time using 1 H, 13 C, 19 F, and 35 Cl nuclear magnetic resonance (NMR) spectroscopy. The controlled environment of the experiments, coupled to the unique sensitivity of NMR, unveiled novel metastable intermediates and the formation of branching networks of products with temporal evolution. Oxidation of the pristine solvent primarily proceeds through a radical pathway that also produces highly reactive protons but faces competition from a second pathway involving a radical carbocation intermediate. In all cases, the intermediates follow a variety of downstream pathways that can intersect with each other. The concomitant network of reactions represents a significant increase in complexity compared to common descriptions in the literature, yet, critically, it helps explain the wide range of products typically identified in electrolyte oxidation in complete cells. The results highlight the need for refocusing fundamental research on anodic stability to analysis of the hierarchy of reaction networks to better inform efforts to mitigate the detrimental effects on battery performance, including prevention and harvesting of proton and radical products.

Electrolytes↗