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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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Search for Pair Production of Strongly Interacting Particles Decaying to Pairs of Jets in pp̄ Collisions at √s=1.96 TeV
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at √s=1.96 TeV corresponding to an integrated luminosity of 6.6 fb⁻¹. We find the data to be consistent with nonresonant production. We report limits on σ(pp̄→jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.
Search for Higgs boson pair production in the b(b)over-barb(b)over-bar final state from pp collisions at root s=8 TeVwith the ATLAS detector
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Study of $WW\gamma $ and $WZ\gamma $ production in $pp$ collisions at $\sqrt{s} = {8} \,{\text {TeV}}$ and search for anomalous quartic gauge couplings with the ATLAS experiment
This paper presents a study of WWγ and WZγ triboson production using events from proton–proton collisions at a centre-of-mass energy of √s = 8 TeV recorded with the ATLAS detector at the LHC and corresponding to an integrated luminosity of 20.2 fb –1 . The WWγ production cross-section is determined using a final state containing an electron, a muon, a photon, and neutrinos (eνμνγ). Upper limits on the production cross-section of the eνμνγ final state and the WWγ and WZγ final states containing an electron or a muon, two jets, a photon, and a neutrino (eνjjγ or μνjjγ) are also derived. The results are compared to the cross-sections predicted by the Standard Model at next-to-leading order in the strong-coupling constant. In addition, upper limits on the production cross-sections are derived in a fiducial region optimised for a search for new physics beyond the Standard Model. The results are interpreted in the context of anomalous quartic gauge couplings using an effective field theory. Confidence intervals at 95% confidence level are derived for the 14 coupling coefficients to which WWγ and WZγ production are sensitive.
Metabolic engineering of Escherichia coli for the production of butyric acid at high titer and productivity
Background: Several anaerobic bacteria produce butyric acid, a commodity chemical with use in chemical, pharmaceutical, food and feed industries, using complex media with acetate as a co-product. Butyrate titer of various recombinant Escherichia coli did not exceed 10 g l -1 in batch fermentations in any of the media tested. Results: A recombinant E. coli (strain LW393) that produced butyrate as the major fermentation product was constructed with genes from E. coli, Clostridium acetobutylicum and Treponema denticola. Strain LW393 produced 323±6 mM (28.4±0.4 g l -1 ) butyric acid in batch fermentations in mineral salt medium with glucose as C source at a yield of 0.37±0.01 g (g glucose consumed) -1 . Butyrate accounted for 90% of the total products produced by the culture. Supplementing this medium with yeast extract further increased butyric acid titer to 375±4 mM. Average volumetric productivity of butyrate with xylose as C source was 0.89±0.07 g l -1 h -1 . Conclusions: The butyrate titer reported in this study is about 2.5–3-times higher than the values reported for other recombinant E. coli and this is achieved in mineral salt medium with an expectation of lower purifcation and production cost of butyrate.
Waste To Wisdom: Utilizing Forest Residues for the Production of Bioenergy and Biobased Products
The Waste to Wisdom project was part of the Biomass Research and Development Initiative (BRDI) and funded by the Department of Energy (DE-EE0006297) at an amount of $5.8 million. Our interdisciplinary research team, consisting of academics, business professionals, and land managers, worked together for about four years (September 2013 to December 2017) to: 1) conduct field-based experiments to develop innovative tools and systems that improve the economics, accessibility, and production of quality feedstocks from forest residues, 2) develop and test stand-alone in-woods or near-the-forest biomass conversion technologies (BCTs) for the production of biochar, torrefied wood, and briquettes, and 3) perform analyses to evaluate the economic feasibility of commercial deployment of BCTs and to quantify the life cycle economic and environmental benefits of utilizing forest residues with BCTs for the production of bioenergy and bioproducts. The research papers presented in this Special Issue cover key aspects of the research efforts and findings made by the project team. We encourage the audience to visit the project web site (http://wastetowisdom.com/) to learn more about the team’s research on feedstock development, biomass conversion technologies, and the financial and environmental benefits of utilizing forest residues for production of bioenergy and biobased products. Keywords: Air quality, Biomass conversion technology, Forest harvesting, Woody biomass.
A Thermophilic Ionic Liquid-Tolerant Cellulase Cocktail for the Production of Cellulosic Biofuels
Generation of biofuels from sugars in lignocellulosic biomass is a promising alternative to liquid fossil fuels, but efficient and inexpensive bioprocessing configurations must be developed to make this technology commercially viable. One of the major barriers to commercialization is the recalcitrance of plant cell wall polysaccharides to enzymatic hydrolysis. Biomass pretreatment with ionic liquids (ILs) enables efficient saccharification of biomass, but residual ILs inhibit both saccharification and microbial fuel production, requiring extensive washing after IL pretreatment. Pretreatment itself can also produce biomass-derived inhibitory compounds that reduce microbial fuel production. Therefore, there are multiple points in the process from biomass to biofuel production that must be interrogated and optimized to maximize fuel production. Here, we report the development of an IL-tolerant cellulase cocktail by combining thermophilic bacterial glycoside hydrolases produced by a mixed consortia with recombinant glycoside hydrolases. This enzymatic cocktail saccharifies IL-pretreated biomass at higher temperatures and in the presence of much higher IL concentrations than commercial fungal cocktails. Sugars obtained from saccharification of IL-pretreated switchgrass using this cocktail can be converted into biodiesel (fatty acid ethyl-esters or FAEEs) by a metabolically engineered strain of E. coli . During these studies, we found that this biodiesel-producing E. coli strain was sensitive to ILs and inhibitors released by saccharification. This cocktail will enable the development of novel biomass to biofuel bioprocessing configurations that may overcome some of the barriers to production of inexpensive cellulosic biofuels.
Waste to Wisdom: Utilizing Forest Residues for the Production of Bioenergy and Biobased Products
The Waste to Wisdom project was part of the Biomass Research and Development Initiative (BRDI) and funded by the Department of Energy (DE-EE0006297) at an amount of $5.8 million. Our interdisciplinary research team, consisting of academics, business professionals, and land managers, worked together for about four years (September 2013 to December 2017) to: 1) conduct field-based experiments to develop innovative tools and systems that improve the economics, accessibility, and production of quality feedstocks from forest residues, 2) develop and test stand-alone in-woods or near-the forest biomass conversion technologies (BCTs) for the production of biochar, torrefied wood, and briquettes, and 3) perform analyses to evaluate the economic feasibility of commercial deployment of BCTs and to quantify the life cycle economic and environmental benefits of utilizing forest residues with BCTs for the production of bioenergy and bioproducts. The research papers presented in this Special Issue cover key aspects of the research efforts and findings made by the project team. We encourage the audience to visit the project web site (http://wastetowisdom.com/) to learn more about the team’s research on feedstock development, biomass conversion technologies, and the financial and environmental benefits of utilizing forest residues for production of bioenergy and biobased products.
Sugarcane Biomass Production in South Florida: A Comparative Emergy Assessment of Organic Soil and Mineral Soil Production Systems
An Emergy Assessment (EMA) of sugarcane cultivation as feedstock for bioethanol production in South Florida was performed to develop a sustainability profile of the farming systems. In this study, a sugarcane farming system on muck soil (organic soil) was compared with a similar crop- ping system on a sandy soil (mineral soil). Our study provides a comparison of these alternative systems from the perspective of their resource use, environmental impact and sustainability. The representative farm for both systems was based on a 5000 acres farm assumed to be already established in South Florida. Emergy analysis was applied to evaluate environmental support required for the sugarcane production in both systems. In line with the methodology a quantitative inventory of free natural resources and purchased input flows into the systems was created. These results showed that aside ground water irrigation which dominates (44%) in both systems, the largest emergy flows for biofuel production on organic soil were associated with soil erosion or subsidence (19%), labor (12%), evapotranspiration (11%), and fuel (8%). However, for sandy soil production, the main contributors were lime (13%), labor (12%), and fuel (8%). Furthermore, the emergy analysis suggests that due to the non-renewability of soil loss in the organic soil farming system, a reduction in the purchased inputs for sandy (mineral) soils based on alternative farming measures potentially makes mineral soil sugarcane ethanol production a rather more sustainable and attractive alternative for a better environmental performance.
Atmospheric leakage and condensate production in NASA's biomass production chamber. Effect of diurnal temperature cycles
A series of tests were conducted to monitor atmospheric leakage rate and condensate production in NASA's Biomass Production Chamber (BPC). Water was circulated through the 64 plant culture trays inside the chamber during the tests but no plants were present. Environmental conditions were set to a 12-hr photoperiod with either a matching 26 C (light)/20 C (dark) thermoperiod, or a constant 23 C temperature. Leakage, as determined by carbon dioxide decay rates, averaged about 9.8 percent for the 26 C/20 C regime and 7.3 percent for the constant 23 C regime. Increasing the temperature from 20 C to 26 C caused a temporary increase in pressure (up to 0.5 kPa) relative to ambient, while decreasing the temperature caused a temporary decrease in pressure of similar magnitude. Little pressure change was observed during transition between 23 C (light) and 23 C (dark). The lack of large pressure events under isothermal conditions may explain the lower leakage rate observed. When only the plant support inserts were placed in the culture trays, condensate production averaged about 37 liters per day. Placing acrylic germination covers over the tops of culture trays reduced condensate production to about 7 liters per day. During both tests, condensate production from the lower air handling system was 60 to 70 percent greater than from the upper system, suggesting imbalances exist in chilled and hot water flows for the two air handling systems. Results indicate that atmospheric leakage rates are sufficiently low to measure CO2 exchange rates by plants and the accumulation of certain volatile contaminants (e.g., ethylene). Control system changes are recommended in order to balance operational differences (e.g., humidity and temperature) between the two halves of the chamber.
Comparative Study of Laboratory-Scale and Prototypic Production-Scale Fuel Fabrication Processes and Product Characteristics
An objective of the High Temperature Gas Reactor fuel development and qualification program for the United States Department of Energy has been to qualify fuel fabricated in prototypic production-scale equipment. The quality and characteristics of the tristructural isotropic coatings on fuel kernels are influenced by the equipment scale and processing parameters. Some characteristics affecting product quality were suppressed while others have become more significant in the larger equipment. Changes to the composition and method of producing resinated graphite matrix material has eliminated the use of hazardous, flammable liquids and enabled it to be procured as a vendor-supplied feed stock. A new method of overcoating TRISO particles with the resinated graphite matrix eliminates the use of hazardous, flammable liquids, produces highly spherical particles with a narrow size distribution, and attains product yields in excess of 99%. Compact fabrication processes have been scaled-up and automated with relatively minor changes to compact quality to manual laboratory-scale processes. The impact on statistical variability of the processes and the products as equipment was scaled are discussed. The prototypic production-scale processes produce test fuels that meet fuel quality specifications.
Optimally placing photovoltaic arrays to maximize value of energy production based on peak power production, local solar radiation, weather, electricity market prices and rate structures
A method, system and computer program product for optimally placing photovoltaic arrays to maximize a value of energy production. Incident solar radiation for various placements of the photovoltaic arrays accommodating different azimuths and tilts is calculated. Alternating current solar photovoltaic electricity energy and power production is then estimated from the calculated solar radiation on a plane and weather data. Furthermore, a value of solar photovoltaic electricity energy and power produced by the photovoltaic arrays for the various placements is calculating using the estimated alternating current solar photovoltaic electricity production. A placement out of the various placements for the photovoltaic arrays is then selected corresponding to a highest value of the solar photovoltaic electricity produced by the photovoltaic arrays. In this manner, the appropriate placement for the photovoltaic arrays is determined that maximizes the value of energy production (where “value” may correspond to an economic value or a non-economic value).
Production of graphene-structured products from coal using thermal molten salt process
The invention provides a method for the production of graphene-structured products. The method generally comprises contacting at a conversion temperature ranging from about 850° C. to about 1100° C. in an inert atmosphere coal with a molten salt to produce a graphene-structured product. In an alternate embodiment, the method comprises contacting at a conversion temperature ranging from about 850° C. to about 1100° C. in an inert atmosphere coal with a molten salt to produce a graphene-structured product; and, separating a rare earth element from the graphene-structured product.
Thermal conversion of municipal solid waste via hydrothermal carbonization: Comparison of carbonization products to products from current waste management techniques
Highlights: Black-Right-Pointing-Pointer Hydrothermal carbonization (HTC) is a novel thermal conversion process. Black-Right-Pointing-Pointer HTC converts wastes into value-added resources. Black-Right-Pointing-Pointer Carbonization integrates majority of carbon into solid-phase. Black-Right-Pointing-Pointer Carbonization results in a hydrochar with high energy density. Black-Right-Pointing-Pointer Using hydrochar as an energy source may be beneficial. - Abstract: Hydrothermal carbonization (HTC) is a novel thermal conversion process that may be a viable means for managing solid waste streams while minimizing greenhouse gas production and producing residual material with intrinsic value. HTC is a wet, relatively low temperature (180-350 Degree-Sign C) thermal conversion process that has been shown to convert biomass to a carbonaceous residue referred to as hydrochar. Results from batch experiments indicate HTC of representative waste materials is feasible, and results in the majority of carbon (45-75% of the initially present carbon) remaining within the hydrochar. Gas production during the batch experiments suggests that longer reaction periods may be desirable to maximize the production of energy-favorable products. If using the hydrochar for applications in which the carbon will remain stored, results suggest that the gaseous products from HTC result in fewer g CO{sub 2}-equivalent emissions than the gases associated with landfilling, composting, and incineration. When considering the use of hydrochar as a solid fuel, more energy can be derived from the hydrochar than from the gases resulting from waste degradation during landfilling and anaerobic digestion, and from incineration of food waste. Carbon emissions resulting from the use of the hydrochar as a fuel source are smaller than those associated with incineration, suggesting HTC may serve as an environmentally beneficial alternative to incineration. The type and extent of environmental benefits derived from HTC will be dependent on hydrochar use/the purpose for HTC (e.g., energy generation or carbon storage).
International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station
Abstract The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward (Bowyer et al., 2013). Fission-based production of 99Mo for medical purposes also releases radioxenon isotopes to the atmosphere (Saey, 2009). One of the ways to mitigate the effect of emissions from medical isotope production is the use of stack monitoring data, if it were available, so that the effect of radioactive xenon emissions could be subtracted from the effect from a presumed nuclear explosion, when detected at an IMS station location. To date, no studies have addressed the impacts the time resolution or data accuracy of stack monitoring data have on predicted concentrations at an IMS station location. Recently, participants from seven nations used atmospheric transport modeling to predict the time-history of 133Xe concentration measurements at an IMS station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well (a high composite statistical model comparison rank or a small mean square error with the measured values). The results suggest release data on a 15 min time spacing is best. The model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. Further research is needed to identify optimal methods for selecting ensemble members and those methods may depend on the specific transport problem. None of the submissions based only on the stack monitoring data predicted the small measured concentrations very well. The one submission that best predicted small concentrations also included releases from nuclear power plants. Modeling of sources by other nuclear facilities with smaller releases than medical isotope production facilities may be important in discriminating those releases from releases from a nuclear explosion.
Electrocatalytic Hydrogen Production by [Ni(7PPh2NH)2]2+: Removing the Distinction Between Endo- and Exo- Protonation Sites
A new Ni(II) complex, [Ni(7PPh2NH)2]2+ (7PPh2NH = 3,6-triphenyl-1-aza-3,6-diphosphacycloheptane) has been synthesized, and its electrochemical properties are reported. The 7PPh2NH ligand features an NH, ensuring properly positioned protonated amine groups (N–H+) for electrocatalysis, regardless of whether protonation occurs exo- or endo- to the metal center. The compound is an electrocatalyst for H2 production in the presence of organic acids (pKa range 10–13 in CH3CN) with turnover frequencies ranging from 160–770 s-1 at overpotentials between 320–470 mV, as measured at the half peak potential of the catalytic wave. In stark contrast to [Ni(PR2NR'2)2]2+ and other [Ni(7PPh2NR')]2+ complexes, catalytic turnover frequencies for H2 production by [Ni(7PPh2NH)2]2+ do not show catalytic rate enhancement upon the addition of H2O. This finding supports the assertion that [Ni(7PPh2NH)2]2+ eliminates the distinction between the endo- and exo-protonation isomers. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.
eA Pion Production at CLAS Aimed at Neutrinos
Preliminary results on semi-inclusive charged pion production in eA collisions at E{sub beam} = 5 GeV/c{sup 2} are presented. The data were collected using the CLAS detector, which is a multipurpose, large acceptance, magnetic spectrometer located in Hall B at the Thomas Jefferson National Accelerator Facility. Distributions in W, Q{sup 2}, p{sub {pi}}, and {theta}{sub {pi}} are shown for data produced using deuterium and carbon targets. Preliminary comparisons with data simulated using the GENIE generator are made. The motivation for this work is to provide distributions useful for tuning the hadronic production models used in extracting results from current and next-generation neutrino oscillation experiments.
Techno-economic and Life Cycle Analysis of MixAlco® Processes for Mixed Alcohol Production from Brown Algae
The need for producing renewable fuels from biomass has increased due to depleting fossil resources and environmental concerns. However, the low fraction of biomass carbon converted to product is an undeniable drawback for most current biofuel productions from fermentation due to undecomposed lignin in biomass composition and carbon loss as CO 2 . In this work, two main production routes of the MixAlco® process, the ketonization route (KR) and esterification route (ER) are evaluated for the mixed alcohol production by brown algae, a third-generation biomass without lignin. A novel fermentation process using syntrophic bacteria consortia (SBC) is developed to produce acetic acid from waste gas produced by KR and ER process. The paper investigates the integrated flowsheet for these alternative routes, using techno-economic and life cycle analysis to compare the minimum selling price and environmental impacts. From TEA, we find that the overall costs for KR and ER are lower than the SBC processes. The cost of ketonization routes is lower than esterification routes. The capital cost and operating cost for the ER+SBC process are the highest. Raw materials and utilities are the two major costs for all the processing routes examined. Here, the MSP for the ER+SBC process is the lowest out of all four routes. ER process performs the best in terms of environmental impacts except in water depletion compared with other processes, while the KR process performs the worst regarding the environmental metrics.