Reduction of PV Module Temperature Using Thermally Conductive Backsheets
Not provided.
Energy & Fuels↗
SEARCH · Engineering Papers
Results for “reduction”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Next-Cycle Optimal Fuel Control for Cycle-to-Cycle Variability Reduction in EGR-Diluted Combustion
In this simulation study, cycle-to-cycle fuel control was used to reduce CCV by injecting additional fuel in operating conditions with sporadic misfires and partial burns. An optimal control policy was proposed that utilizes 1) a physics-based model that tracks in-cylinder gas composition and 2) a one-step-ahead prediction of the combustion efficiency based on a kernel density estimator. The optimal solution, however, presents a tradeoff between the reduction in combustion CCV and the increase in fuel injection quantity required to stabilize the charge. Such a tradeoff can be ad- just by a single parameter embedded in the cost function.
Maldonado, BryanP. [Oak Ridge National Lab. (ORNL)↗
Cost Reduction of School Bus Fleet Electrification With Optimized Charging and Distributed Energy Resources: Preprint
Considerations for electrifying school buses are presented with an analysis of battery sizing to match bus driving requirements. The charging and vehicle-to-building dispatch of the electric school buses were optimized to evaluate the potential to reduce the impact of the bus charging on the school's electric utility bill. Distributed energy resources (DER) and flexible building loads were also considered with the school bus electrification to evaluate the further reduction in energy costs with enhanced system integration and optimized dispatch. The effect of degradation on the school bus batteries was analyzed to determine if the smart charging and vehicle-to-building battery operation decreases the life of the battery. The results show that there is an opportunity to mitigate the increase of electric utility bills with improved charging controls and bi-directionally operating the school bus batteries to reduce building demand charges. The battery degradation analysis using dispatch with optimized charging and discharging shows acceptable battery life.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Reduction of CO2 Emissions Due to Wind Energy - Methods and Issues in Estimating Operational Emission Reductions
This paper presents ways of estimating CO2 reductions of wind power using different methodologies. Estimates based on historical data have more pitfalls in methodology than estimates based on dispatch simulations. Taking into account exchange of electricity with neighboring regions is challenging for all methods. Results for CO2 emission reductions are shown from several countries. Wind power will reduce emissions for about 0.3-0.4 MtCO2/MWh when replacing mainly gas and up to 0.7 MtCO2/MWh when replacing mainly coal powered generation. The paper focuses on CO2 emissions from power system operation phase, but long term impacts are shortly discussed.
17 WIND ENERGY↗
A designed heme-[4Fe-4S] metalloenzyme catalyzes sulfite reduction like the native enzyme
Multielectron redox reactions often require multicofactor metalloenzymes to facilitate coupled electron and proton movement, but it is challenging to design artificial enzymes to catalyze these important reactions, owing to their structural and functional complexity. Here, we report a designed heteronuclear heme-[4Fe-4S] cofactor in cytochrome c peroxidase as a structural and functional model of the enzyme sulfite reductase. The initial model exhibits spectroscopic and ligand-binding properties of the native enzyme, and sulfite reduction activity was improved—through rational tuning of the secondary sphere interactions around the [4Fe-4S] and the substrate-binding sites—to be close to that of the native enzyme. By offering insight into the requirements for a demanding six-electron, seven-proton reaction that has so far eluded synthetic catalysts, this study provides strategies for designing highly functional multicofactor artificial enzymes.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Effect of Ammonia on the Electrocatalysis of Oxygen Reduction Reaction in Base
We investigated the effect of ammonia on the activity of seven benchmark oxygen reduction reaction (ORR) electrocatalysts, Pt/C, Pd/C, Au/C, Ag/C, commercial Fe–N–C, zeolitic imidazolate framework (ZIF)-based Fe–N–C (Fe-ZIF), and ZIF-based Fe,Co–N–C (Fe,Co-ZIF) in alkaline media and direct ammonia fuel cell (DAFC) relevant conditions using a rotating disk electrode. We found that ammonia exposure causes considerable ORR activity loss for all studied electrocatalysts. Should we rank the electrocatalysts in terms of their ORR activity loss and their irreversible ORR activity loss as the result of exposure to ammonia (from the highest loss to the lowest loss), we get Au/C > Pt/C ≈ Pd/C > Ag/C » commercial Fe–N–C > Fe-ZIF ≈ Fe,Co-ZIF and Pd/C > Au/C > Ag/C > commercial Fe–N–C > Fe-ZIF ≈ Fe,Co-ZIF > Pt/C, respectively. The ammonia oxidation reaction activity and adsorptive properties of the Gerisher-Mauerer reaction intermediates do not govern the trend of the ORR activity loss of Pt/C, Pd/C, Au/C, and Ag/C electrocatalysts. Notably, we found that Pt/C electrocatalyst shows the lowest irreversible ORR activity loss, while Fe-ZIF and Fe,Co-ZIF electrocatalysts show the lowest overall ORR activity loss. Our comprehensive study suggests that Pt-based, Fe-ZIF, and Fe,Co-ZIF electrocatalysts are promising cathode candidates for future DAFCs.
Abbasi, Reza (ORCID:0000000249384151)↗
THE DATA REDUCTION PIPELINE FOR THE SDSS-IV MaNGA IFU GALAXY SURVEY
Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) is an optical fiber-bundle integral-field unit (IFU) spectroscopic survey that is one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV). With a spectral coverage of 3622–10354 Å and an average footprint of ∼500 arcsec{sup 2} per IFU the scientific data products derived from MaNGA will permit exploration of the internal structure of a statistically large sample of 10,000 low-redshift galaxies in unprecedented detail. Comprising 174 individually pluggable science and calibration IFUs with a near-constant data stream, MaNGA is expected to obtain ∼100 million raw-frame spectra and ∼10 million reduced galaxy spectra over the six-year lifetime of the survey. In this contribution, we describe the MaNGA Data Reduction Pipeline algorithms and centralized metadata framework that produce sky-subtracted spectrophotometrically calibrated spectra and rectified three-dimensional data cubes that combine individual dithered observations. For the 1390 galaxy data cubes released in Summer 2016 as part of SDSS-IV Data Release 13, we demonstrate that the MaNGA data have nearly Poisson-limited sky subtraction shortward of ∼8500 Å and reach a typical 10 σ limiting continuum surface brightness μ = 23.5 AB arcsec{sup −2} in a five-arcsecond-diameter aperture in the g -band. The wavelength calibration of the MaNGA data is accurate to 5 km s{sup −1} rms, with a median spatial resolution of 2.54 arcsec FWHM (1.8 kpc at the median redshift of 0.037) and a median spectral resolution of σ = 72 km s{sup −1}.
79 ASTRONOMY AND ASTROPHYSICS↗
Data for "1H NMR quantification of aromatic monomers from reductive catalytic fractionation"
Data here corresponds to the data presented in the academic publication titled "1H NMR quantification of aromatic monomers from reductive catalytic fractionation" set to be published in ACS Sustainable Chemistry and Engineering. Data was gathered at the National Renewable Energy Laboratory From 2022-2025.
09 BIOMASS FUELS↗
Reduction of bacterial dissemination. germicidal activity of ethylene oxide. reduction of bacterial contamination on surfaces third quarterly summary report of progress
Bacteria dissemination reduction, ethylene oxide germicidal activity, and bacteria contamination reduction on surfaces
ETHYLENE OXIDE↗
Studies on reduction of noble metal surface oxides in relation to electrochemical oxygen reduction Semiannual report
Reduction of noble metal surface oxides in relation to electrochemical oxygen reduction
Source record↗
The FAST Hipparcos data reduction consortium - Overview of the reduction software
The main features of the data analysis methods adopted by FAST in the calibration and processing of the Hipparcos data are discussed. The structure of the data reduction software is examined, and the actual processing and evaluation are presented. Attention is given to the first look task, the calibration task, data preparation, attitude determination, the great circle reduction, synthesis treatment, iterations, data management and command software, and follow-up and evaluation activities.
Kovalevsky, J.↗
Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels
Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32–42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0–0.9 V, 0.9–1.95 V, and 1.95–3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO 2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H 2 and CO) and Hythane (H 2 and CH 4 ) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. Finally, we show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C 2 H 4 have high profitability indices.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Large-scale inverse model analyses employing fast randomized data reduction: INVERSE MODELING WITH DATA REDUCTION
When the number of observations is large, it is computationally challenging to apply classical inverse modeling techniques. We have developed a new computationally efficient technique for solving inverse problems with a large number of observations (e.g., on the order of 10 7 or greater). Our method, which we call the randomized geostatistical approach (RGA), is built upon the principal component geostatistical approach (PCGA). We employ a data reduction technique combined with the PCGA to improve the computational efficiency and reduce the memory usage. Specifically, we employ a randomized numerical linear algebra technique based on a so-called “sketching” matrix to effectively reduce the dimension of the observations without losing the information content needed for the inverse analysis. In this way, the computational and memory costs for RGA scale with the information content rather than the size of the calibration data. Our algorithm is coded in Julia and implemented in the MADS open-source high-performance computational framework (http://mads.lanl.gov). We apply our new inverse modeling method to invert for a synthetic transmissivity field. Compared to a standard geostatistical approach (GA), our method is more efficient when the number of observations is large. Moreover, our method is capable of solving larger inverse problems than the standard GA and PCGA approaches. Thus, our new model inversion method is a powerful tool for solving large-scale inverse problems. The method can be applied in any field and is not limited to hydrogeological applications such as the characterization of aquifer heterogeneity.
54 ENVIRONMENTAL SCIENCES↗
Enhancing Oxygen Reduction Activity and Cr Tolerance of Solid Oxide Fuel Cell Cathodes by a Multiphase Catalyst Coating
Intermediate temperature solid oxide fuel cells (IT-SOFCs) are cost-effective and efficient energy conversion systems. Here, the sluggish oxygen reduction reaction (ORR) and the degradation of cathodes are critical challenges to the commercialization of IT-SOFCs. Here, a highly efficient multiphase (MP) catalyst coating, consisting of Ba 1–x Co 0.7 Fe 0.2 Nb 0.1 O 3–δ (BCFN) and BaCO 3 , to enhance the ORR activity and durability of the state-of-the-art lanthanum strontium cobalt ferrite (La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3–δ , LSCF) cathode is reported. The conformal MP catalyst-coated LSCF cathode shows a polarization resistance (R p ) of 0.048 Ω cm 2 at 650 °C, about one order of magnitude smaller than that of the bare LSCF. In an accelerated Cr-poisoning test, the degradation rate of the catalyst-coated LSCF electrode is 10 –3 Ω cm 2 h –1 (0.59% h –1 ) over 200 h, only one fifth of the degradation rate of the bare LSCF electrode at 750 °C. In addition, anode-supported single cells with the MP catalyst-coated LSCF cathode show a dramatically enhanced peak power density (1.4 W cm –2 vs 0.67 W cm –2 at 750 °C) and increased durability against Cr and H 2 O. Both experimental results and density functional theory-based calculations indicate that the BCFN phase improves the ORR activity while the BaCO 3 phase enhances the stability of the LSCF cathode.
solid oxide fuel cells↗
From Metal-Organic Frameworks to Single-Atom Fe Implanted N-doped Porous Carbons: Efficient Oxygen Reduction in Both Alkaline and Acidic Media [From MOFs to Single Fe Atoms Implanted N-doped Porous Carbons: Efficient Oxygen Reduction in Both Alkaline and Acidic Media]
Here, it remains highly desired but a great challenge to achieve atomically dispersed metals in high loadings for efficient catalysis. Now porphyrinic metal–organic frameworks (MOFs) have been synthesized based on a novel mixed–ligand strategy to afford high–content (1.76 wt %) single–atom (SA) iron–implanted N–doped porous carbon (Fe SA –N–C) via pyrolysis. Thanks to the single–atom Fe sites, hierarchical pores, oriented mesochannels and high conductivity, the optimized Fe SA –N–C exhibits excellent oxygen reduction activity and stability, surpassing almost all non–noble–metal catalysts and state–of–the–art Pt/C, in both alkaline and more challenging acidic media. More far–reaching, this MOF–based mixed–ligand strategy opens a novel avenue to the precise fabrication of efficient single–atom catalysts.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Thermally Driven Structure and Performance Evolution of Atomically Dispersed FeN[subscript 4] Sites for Oxygen Reduction
Abstract not provided
Li, Jiazhan↗