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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Spatial Engineering Direct Cooperativity between Binding Sites for Uranium Sequestration

Preorganization is a basic design principle used by nature that allows for synergistic pathways to be expressed. Herein, a full account of the conceptual and experimental development from randomly distributed functionalities to a convergent arrangement that facilitates cooperative binding is given, thus conferring exceptional affinity toward the analyte of interest. The resulting material with chelating groups populated adjacently in a spatially locked manner displays up to two orders of magnitude improvement compared to a random and isolated manner using uranium sequestration as a model application. This adsorbent shows exceptional extraction efficiencies, capable of reducing the uranium concentration from 5 ppm to less than 1 ppb within 10 min, even though the system is permeated with high concentrations of competing ions. The efficiency is further supported by its ability to extract uranium from seawater with an uptake capability of 5.01 mg g -1 , placing it among the highest-capacity seawater uranium extraction materials described to date. The concept presented here uncovers a new paradigm in the design of efficient sorbent materials by manipulating the spatial distribution to amplify the cooperation of functions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Selective Electrochemical Reduction of CO 2 to Metal Oxalates in Nonaqueous Solutions Using Trace Metal Pb on Carbon Supports Enhanced by a Tailored Microenvironment

In this work, the electroreduction of carbon dioxide (CO 2 ) to oxalate is enabled by incorporating trace metallic lead (Pb) on carbon‐based supports (CBS) with polymer overlayers. These composite materials serve as an efficient electrocatalytic system for the facile conversion and storage of CO 2 , a pernicious atmospheric pollutant. Results from controlled potential electrolysis experiments indicate that 1) trace metallic Pb on the ppb scale is active toward the reductive coupling of CO 2 to oxalate at comparable Faradaic efficiencies to bulk metallic Pb and 2) polymer encapsulation of this trace metallic Pb leads to promotion of CO 2 reduction (CO 2 R) selectively to metal oxalates over other products such as CO. Importantly, metal oxalates are important alternative cementitious materials and precursors for other materials’ synthesis applications. The solid products undergo rigorous spectroscopic characterization, including 13 CO 2 labeling experiments, to ensure the metal oxalates are in fact produced from CO 2 R. These findings serve as a model for leveraging microenvironment effects to enhance activity and selectivity for CO 2 R using trace‐metal catalysts for carbon utilization and storage technologies.

alternative cementitious materials↗
DOE OSTI2021

Quantifying adherence of oxide scales on steels exposed to high temperature and pressure steam

Oxide scale exfoliation is a major concern in fossil fuel power generation because it can cause tube blockages and erode valves and steam turbine components downstream. There is still considerable scientific and commercial interest to improve the mechanistic understanding of oxide failures by developing models to predict exfoliation and the extent of tube blockage as a function of operating conditions and component geometries. Tensile testing inside a scanning electron microscope was conducted on ferritic–martensitic and austenitic steel specimens with the steam side (Fe,Cr)-rich oxides grown after exposures for up to 1000 h in steam with ~100 ppb O 2 at 276 bar and 550°C. Multiple oxide layer cracks and delamination events were observed and analyzed in detail during the tests. Results from the testing agreed well with earlier observations that had identified the failure location at the outer–inner oxide layer for all tested materials. Calculated adhesion energies identified the outer–inner oxide interface of alloy 347HFG as the weakest interface.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Demonstration of no catalytical activity of Fe–N–C and Nb–N–C electrocatalysts toward nitrogen reduction using in–line quantification

Ammonia (NH 3 ) production via the electrochemical nitrogen reduction reaction (NRR) is a promising method for sustainable generation of this important chemical. Efforts are ongoing in finding an efficient, stable, and selective catalyst that will enable the reaction. However, progress is hindered in the field due to lack of reproducibility, most likely a consequence of reports of false-positive results due to improper measurement control and methods. In this study, we explore the NRR activity of a promising class of single atom catalysts, transition metal-nitrogen-carbon (M-N-C) electrocatalysts. Using a state-of-the-art in-line ammonia quantification methodology, with detection limit as low as 1 ppb for ammonia, we show that single atom Nb and Fe embedded in a stable carbon and nitrogen framework do not electrochemically reduce N 2 to NH 3 . Critically, this demonstrates that our experimental setup with in-line sequential injection analysis successfully excludes ammonia contamination from the gas supply and atmospheric sources, allowing for thorough and high-throughput examination of potential NRR catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

D Meson Sensitivity to a System Size Scan at LHC

Experimental measurements in pA collisions indicate no D meson suppression (R pPb ~ 1) but a surprisingly large v 2 . To better understand these results we propose a system size scan at the LHC involving 16 OO, 40 ArAr, 129 XeXe and 208 PbPb collisions. Using Trento+ v-USPhydro+DAB-MOD to make predictions, we find that the R AA tends towards unity when the system size is decreased, but nonetheless, in the most central collisions v 2 {2} is almost independent of the colliding system. Furthermore, these results are analyzed in light of path length and initial eccentricity variations.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Impact of fully coherent energy loss on heavy meson production in pA collisions

Hadron production in proton-nucleus (pA) collisions was previously shown to be suppressed by medium-induced fully coherent energy loss (FCEL). We show that the quenching of D and B mesons in pPb collisions at the LHC due solely to FCEL is, at least, on par with other nuclear effects such as gluon shadowing or saturation. This is consistent with previous findings for both quarkonium and light hadron production in pA collisions, emphasising that FCEL effects need to be included for a reliable understanding of hadron production measurements in pA collisions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Measurement of inclusive charged-particle b-jet production in pp and p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

A measurement of the inclusive b-jet production cross section is presented in pp and p-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV, using data collected with the ALICE detector at the LHC. The jets were reconstructed in the central rapidity region |η| < 0.5 from charged particles using the anti-k T algorithm with resolution parameter R = 0.4. Identification of b jets exploits the long lifetime of b hadrons, using the properties of secondary vertices and impact parameter distributions. The p T -differential inclusive production cross section of b jets, as well as the corresponding inclusive b-jet fraction, are reported for pp and p-Pb collisions in the jet transverse momentum range 10 ≤ p T,ch jet ≤ 100 GeV/c, together with the nuclear modification factor, $R^{b-jet}_{pPb}$. The analysis thus extends the lower p T limit of b-jet measurements at the LHC. The nuclear modification factor is found to be consistent with unity, indicating that the production of b jets in p-Pb at $\sqrt{s_{NN}}$ = 5.02 TeV is not affected by cold nuclear matter effects within the current precision. The measurements are well reproduced by POWHEG NLO pQCD calculations with PYTHIA fragmentation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Measurement of the Z boson production cross-section in pp collisions at $ \sqrt{s}$ = 5.02 TeV

The first measurement of the Z boson production cross-section at centre-of-mass energy $\sqrt{s}$ = 5.02 TeV in the forward region is reported, using pp collision data collected by the LHCb experiment in year 2017, corresponding to an integrated luminosity of 100 ± 2 pb –1 . The production cross-section is measured for final-state muons in the pseudorapidity range 2.0 < η < 4.5 with transverse momentum p T > 20 GeV/c. The integrated cross-section is determined to be ${\sigma}_{Z\to \mu +\mu -}=39.6\pm 0.7\left(\textrm{stat}\right)\pm 0.6\left(\textrm{syst}\right)\pm 0.8\left(\textrm{lumi}\right)\textrm{pb}$ for the di-muon invariant mass in the range 60 < M μμ < 120 GeV/c 2 . This result and the differential cross-section results are in good agreement with theoretical predictions at next-to-next-to-leading order in the strong coupling constant. Based on a previous LHCb measurement of the Z boson production cross-section in pPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV, the nuclear modification factor RpPb is measured for the first time at this energy. The measured values are ${1.2}_{-0.3}^{+0.5}$ (stat) ± 0.1(syst) in the forward region (1.53 < ${y}_{\mu}^{\ast }$ < 4.03) and ${3.6}_{-0.9}^{+1.6}$ (stat) ± 0.2(syst) in the backward region (–4.97 < ${y}_{\mu}^{\ast }$ < –2.47), where ${y}_{\mu}^{\ast }$ represents the muon rapidity in the centre-of-mass frame.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Study of Drell-Yan dimuon production in proton-lead collisions at $\sqrt{s_\mathrm{NN}} =$ 8.16 TeV

Differential cross sections for the Drell-Yan process, including Z boson production, using the dimuon decay channel are measured in proton-lead (pPb) collisions at a nucleon-nucleon centre-of-mass energy of 8.16 TeV. A data sample recorded with the CMS detector at the LHC is used, corresponding to an integrated luminosity of 173 nb$^{−1}$. The differential cross section as a function of the dimuon mass is measured in the range 15–600 GeV, for the first time in proton-nucleus collisions. It is also reported as a function of dimuon rapidity over the mass ranges 15–60 GeV and 60–120 GeV, and ratios for the p-going over the Pb-going beam directions are built. In both mass ranges, the differential cross sections as functions of the dimuon transverse momentum p$_{T}$ and of a geometric variable ϕ$^{*}$ are measured, where ϕ$^{*}$ highly correlates with p$_{T}$ but is determined with higher precision. In the Z mass region, the rapidity dependence of the data indicate a modification of the distribution of partons within a lead nucleus as compared to the proton case. The data are more precise than predictions based upon current models of parton distributions.[graphic not available: see fulltext]

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Measurement of the ${\Lambda}_c^{+}$ to D 0 production ratio in peripheral PbPb collisions at $\sqrt{s_{\textrm{NN}}}$ = 5.02 TeV

We report on a measurement of the ${\Lambda}_c^{+}$ to D 0 production ratio in peripheral PbPb collisions at $\sqrt{s_{\textrm{NN}}}$ = 5.02 TeV with the LHCb detector in the forward rapidity region 2 < y < 4.5. The ${\Lambda}_c^{+}$ (D 0 ) hadrons are reconstructed via the decay channel ${\Lambda}_c^{+}$ → pK – π + (D 0 → K – π + ) for 2 < p T < 8 GeV/c and in the centrality range of about 65–90%. The results show no significant dependence on p T , y or the mean number of participating nucleons. They are also consistent with similar measurements obtained by the LHCb collaboration in pPb and Pbp collisions at $\sqrt{s_{\textrm{NN}}}$ = 5.02 TeV. The data agree well with predictions from PYTHIA in pp collisions at $\sqrt{s}$ = 5 TeV but are in tension with predictions of the Statistical Hadronization model.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Measurement of nuclear effects on ψ(2S) production in p-Pb collisions at $ \sqrt{s_{\mathrm{NN}}}$ = 8.16 TeV

Inclusive ψ (2S) production is measured in p-Pb collisions at the centre-of-mass energy per nucleon-nucleon pair \( \sqrt{s_{\mathrm{NN}}} \) = 8.16 TeV, using the ALICE detector at the CERN LHC. The production of ψ (2S) is studied at forward (203 < y cms < 3 . 53) and backward (-4.46 < y cms < -2.96) centre-of-mass rapidity and for transverse momentum p T < 12 GeV/ c via the decay to muon pairs. In this paper, we report the integrated as well as the y cms - and p T -differential inclusive production cross sections. Nuclear effects on ψ (2S) production are studied via the determination of the nuclear modification factor that shows a strong suppression at both forward and backward centre-of-mass rapidities. Comparisons with corresponding results for inclusive J/ ψ show a similar suppression for the two states at forward rapidity (p-going direction), but a stronger suppression for ψ (2S) at backward rapidity (Pb-going direction). As a function of p T , no clear dependence of the nuclear modification factor is found. The relative size of nuclear effects on ψ (2S) production compared to J/ ψ is also studied via the double ratio of production cross sections [ σ ψ (2S) /σ J /ψ ]pPb/[ σ ψ (2S) /σ J /ψ ] pp between p-Pb and pp collisions. The results are compared with theoretical models that include various effects related to the initial and final state of the collision system and also with previous measurements at \( \sqrt{s_{\mathrm{NN}}} \) = 5.02 TeV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

J/ψ production at midrapidity in p-Pb collisions at $ \sqrt{s_{\textrm{NN}}}$ = 8.16 TeV

The production of inclusive, prompt and non-prompt J/ψ was studied for the first time at midrapidity (–1.37 < y cms < 0.43) in p-Pb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV with the ALICE detector at the LHC. The inclusive J/ψ mesons were reconstructed in the dielectron decay channel in the transverse momentum (p T ) interval 0 < p T < 14 GeV/c and the prompt and non-prompt contributions were separated on a statistical basis for p T > 2 GeV/c. The study of the J/ψ mesons in the dielectron channel used for the first time in ALICE online single-electron triggers from the Transition Radiation Detector, providing a data sample corresponding to an integrated luminosity of 689 ± 13 μb –1 . The proton-proton reference cross section for inclusive J/ψ was obtained based on interpolations of measured data at different centre-of-mass energies and a universal function describing the p T -differential J/ψ production cross sections. The p T -differential nuclear modification factors R pPb of inclusive, prompt, and non-prompt J/ψ are consistent with unity and described by theoretical models implementing only nuclear shadowing.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Fully coherent energy loss effects on light hadron production in pA collisions

We single out the role of fully coherent induced gluon radiation on light hadron production in pA collisions. The effect has the same general features as for quarkonium production, however with a richer color structure as the induced radiation depends on the global color charge of the partonic subprocess final state. Baseline predictions for light hadron nuclear suppression in pPb collisions at the LHC are provided, taking into account only the effect of fully coherent energy loss, which proves to be of the same order of magnitude as gluon shadowing or saturation. This underlines the need to include fully coherent energy loss in phenomenological studies of hadron production in pA collisions.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2026

How exudates production along a phosphorus gradient influences mineral dissolution across contrasting soil development stages

Harnessing rhizosphere processes offers a valuable opportunity to optimize nutrient use efficiency in agroecosystems. In nutrient-limited soils, plants discharge part of photosynthate surplus via root exudation, including carboxylates, which may enhance mineral dissolution and nutrient mobilization. We aimed to assess how plant responses to nutrient limitation translated into changes in exudate profiles, and how these exudates, in turn, drive bioweathering processes across soils of contrasting mineralogy and weathering degree. We conducted a hydroponic experiment with Lupinus albus grown under five phosphorus (P) concentrations (5, 10, 20, 30, and 50 µM) over seven weeks. We measured plant biomass and root traits, performed a metabolomics analysis and quantified seven carboxylates in root exudates using gas chromatography-mass spectrometry. To assess bioweathering processes across contrasted soil domains, we conducted batch dissolution tests with exudates using three soil horizons—35 each with distinct physicochemical properties: enriched in organic matter, iron oxides, or primary silicates. At the intermediate level of P supply, shoot biomass was comparable to that under high P, but plants produced more root biomass and a higher total carboxylate exudation rate. Despite low carboxylate concentrations (<100 ppb), exudates promoted the dissolution of Ca, Mg, Si, Fe, P and K in all horizons. Yet, the degree of element released varied among horizons. These findings highlight the importance of root exudates in enhancing mineral dissolution, with effects dependent on soil physicochemical properties. The results suggest that managing agroecosystems under moderate nutrient limitation could be a sustainable strategy to increase root-to-shoot ratios, enhance bioweathering processes and nutrient release in soil solution.

Pollet, Sasha L.↗
DOE OSTI2023

Rapid increase in tropospheric ozone over Southeast Asia attributed to changes in precursor emission source regions and sectors

Observations indicate that tropospheric ozone (O 3 ) concentrations over Southeast Asia have been increasing rapidly since the 1990s. Here, we quantify source contributions from geographical regions and emission sectors of the two distinct types of O 3 precursors, i.e., nitrogen oxides (NO x ) and volatile organic compounds (VOCs), to the increase in tropospheric O 3 in Southeast Asia during 1990–2019 using an O 3 source tagging technique implemented in a global chemistry-climate model. In this work, the results show that although local anthropogenic emission of NO x in Southeast Asia only contributes 18% of the annual averaged near-surface O 3 concentration, the increase in local NO x emission dominates the increasing trend of O 3 concentration in Southeast Asia, accounting for 107% of the regional averaged trend of 1.07 ppb decade -1 . Increases in NO x emissions from East Asia and South Asia explain 29% of the increasing trend, but 9% is offset by the emission reduction in North America. Ground transportation is responsible for 79% of the rapid O 3 increase, followed by 39% contribution from international shipping. Because an increase in anthropogenic NO x emissions enhances the O 3 production efficiency by VOCs, the increase in near-surface O 3 concentrations in Southeast Asia is thereby largely contributed by methane and biogenic VOCs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Impact of wildfires on regional ozone and PM 2.5 : Considering the light absorption of Brown carbon

The influence of wildfire brown carbon (BrC) in moderating the formation of O 3 and fine particulate matter (PM 2.5 ) due to its absorption of ultraviolet (UV) radiation is, for the first time, investigated using a modified community multiscale air quality (CMAQ) model. The wavelength-dependent imaginary refractive index of the organic carbon from wildfires, which are needed by the CMAQ model for its inline photolysis rate calculation, are generated experimentally from wood burning aerosols from a combustion chamber. On high emission days of the Bastrop County Complex fire in Texas in early September 2011, BrC UV absorption reduces the daytime average NO 2 photolysis rate by up to 38% in the core region of the wildfire plume compared to the base scenario that does not consider BrC absorption. Consequently, O 3 production in the smoke plume is suppressed compared to the base scenario due to reduced HO x radical concentrations. Further, in the core region, the predicted O 3 increase due to wildfire reaches as high as 47–123 ppb without considering BrC absorption, the predicted increase of O 3 is 5–15% lower when BrC absorption is considered. Similarly, considering the BrC UV absorption leads to approximately 1% (or ~2–3 µgm -3 ) lower estimation of the wildfire emissions’ impact on total PM 2.5 . This change is small because secondary aerosols, which are the components affected by BrC absorption, only account for a small fraction of the total PM 2.5 in wildfire impacted regions in this study. In addition, our study shows that assumptions about aerosol mixing state (core-shell vs. homogeneous) in the inline photolysis rate calculation would not significantly affect out assessment of the impact of wildfire BrC light absorption on O 3 and PM 2.5 .

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Source attribution of near-surface ozone pollution in Jiangsu Province of China over 2013–2019

Near-surface ozone (O3) is one of the most severe air pollutants in China, particularly over densely populated Jiangsu Province in the Yangtze River Delta. In this study, an O3 source tagging technique is utilized in a chemistry-climate model to quantify the source contributions of various emission sectors and regions for nitrogen oxides (NOx) and volatile organic compounds (VOCs) to O3 concentrations in Jiangsu Province during 2013–2019. The results show that the near-surface O3 in Jiangsu Province is mainly contributed by surrounding and remote anthropogenic NOx emissions through long-range transport. Local anthropogenic NOx emissions account for only 13 % and 18 % of the annual and summertime mean near-surface O3 in Jiangsu Province, respectively. Anthropogenic NOx emissions from the surface transportation, industry, and energy sectors account for 21 %, 22 % and 20 % of the annual mean near-surface O3 concentration in Jiangsu Province, respectively. Biogenic and anthropogenic VOCs emissions each explains one-third of the annual mean near-surface O3 concentration in Jiangsu, while methane and stratospheric chemical production contribute 21 % and 6 %, respectively. The sources from stratospheric production, aircraft, lightning, and foreign emissions are the primary contributors to O3 in the mid- and high troposphere. During high pollution days in Jiangsu Province, the near-surface O3 concentrations increase with the maximum exceeding 20 ppb, which is attributed to both the enhanced photochemical production and regional transport in favorable meteorological conditions.

ozone pollution↗
DOE OSTI2021

Highly efficient, rapid, and concurrent removal of toxic heavy metals by the novel 2D hybrid LDH–[Sn 2 S 6 ]

According to a United Nations report, by 2050 nearly six billion people worldwide will suffer from clean water scarcity. This is mostly because of the exponential proliferation of world population, urbanization, industrialization, and water pollution. Heavy metals are common water pollutants that can pose grave public health consequences. Existing water purification systems are lack of materials that have the potential for quick, simultaneous, efficient, and cost-efficient removal of numerous toxic metals from wastewater. Here, in this work, we report the design and synthesis of an economically viable Layered Double Hydroxides - Stannic Sulfide, LDH–[Sn 2 S 6 ] that exhibits a rapid, efficient, selective, and concurrent removal of Cu 2+ , Ag + , Cd 2+ , Pb 2+ , and Hg 2+ from parts per million (ppm) level to below 5 parts per billion (ppb) satisfying World Health Organization’s (WHO) safe drinking water limit. Moreover, LDH–[Sn 2 S 6 ] shows exceptionally high removal efficiencies of the above metals in acidic, neutral, and basic conditions. LDH–[Sn 2 S 6 ] also demonstrates enormous sorption capacities of 378, 978, 332, 579, and 666 mg/g for Cu 2+ , Ag + , Cd 2+ , Pb 2+ , and Hg 2+ , respectively. Remarkably, LDH–[Sn 2 S 6 ] displays extraordinary tolerance to the concentrations of Na + , Ca 2+ , Mg 2+ , Cl - , CO 3 2– , NO 3 – ,and SO 4 2- , and other constituents in tap and river water, it efficiently sequestrates Cu 2+ , Ag + , Cd 2+ , Pb 2+ , and Hg 2+ from ppm to safe drinking water levels in minutes. LDH–[Sn 2 S 6 ] shows pseudo-second-order sorption kinetics suggesting chemisorption adsorption mechanism involving M–S bonding. Altogether, the regeneratable LDH–[Sn 2 S 6 ] becomes an exceptional material that shows ultrahigh removal, unprecedented selectivity, rapid adsorption kinetics, wide pH stability, and a massive adsorption capacity. The integration of these features places LDH–[Sn 2 S 6 ] at the top of all adsorbents known to date and thus could be used for wastewater purifications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗