Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “PRODUCTIVITY”

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.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Biomass Feedstocks for Renewable Fuel Production: A review of the impacts of feedstock and pretreatment on the yield and product distribution of fast pyrolysis bio-oils and vapors

Renewable transportation fuels from biomass have the potential to substantially reduce greenhouse gas emissions and diversify global fuel supplies. Thermal conversion by fast pyrolysis converts up to 75% of the starting plant material (and its energy content) to a bio-oil intermediate suitable for upgrading to motor fuel. Woody biomass, by far the most widely-used and researched material, is generally preferred in thermochemical processes due to its low ash content and high quality bio-oil produced. However, the availability and cost of biomass resources, e.g. forest residues, agricultural residues, or dedicated energy crops, vary greatly by region and will be key determinates in the overall economic feasibility of a pyrolysis-to-fuel process. Formulation or blending of various feedstocks, combined with thermal and/or chemical pretreatment, could facilitate a consistent, high-volume, lower-cost biomass supply to an emerging biofuels industry. However, the impact of biomass type and pretreatment conditions on bio-oil yield and quality, and the potential process implications, are not well understood. This literature review summarizes the current state of knowledge regarding the effect of feedstock and pretreatments on the yield, product distribution, and upgradability of bio-oil.

09 BIOMASS FUELS↗
DOE OSTI2012

Search for pair production of the scalar top quark in muon plus tau final states

Here, we present a search for the pair production of scalar top quarks ($\sim\atop{t}$ 1 ), the lightest supersymmetric partners of the top quarks, in $p\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV, using data corresponding to an integrated luminosity of 7.3fb -1 collected with the D0 experiment at the Fermilab Tevatron Collider. Each scalar top quark is assumed to decay into a b quark, a charged lepton, and a scalar neutrino (ν˜). We investigate final states arising from$\sim\atop{t}$ 1 $≂\atop{t}$ 1 →$b\bar{b}$ μτ$\sim\atop{v}$$\sim\atop{v}$ and $\sim\atop{t}$ 1 $≂\atop{t}$ 1 →$b\bar{b}$ ττ$\sim\atop{v}$$\sim\atop{v}$. With no significant excess of events observed above the background expected from the standard model, we set exclusion limits on this production process in the (m$\sim\atop{t}$ 1 , m$\sim\atop{v}$) plane.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Wind Turbine Design Optimization for Hydrogen Production

To help meet the need for inexpensive green fuels, we are working on wind turbine design optimization specifically for hydrogen production. We have thus far achieved a 1.53% decrease in LCOH as compared to a turbine optimized for LCOE using the same code, design variables, and models. We accomplished this by optimizing some components of the wind turbine tower, rotor, and drivetrain design with hydrogen production and costs in the design loop.

hydrogen↗
DOE OSTI2011

Measurement of the t-Channel Single Top Quark Production Cross Section in pp Collisions at {radical}(s)=7 TeV

Electroweak production of the top quark is measured for the first time in pp collisions at {radical}(s)=7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb{sup -1}. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top-quark production. The combined measurement of the cross section is 83.6{+-}29.8(stat+syst){+-}3.3(lumi) pb, consistent with the standard model expectation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Measurements of differential cross sections of top quark pair production in association with jets in pp collisions at $\sqrt{s}=13 $ TeV using the ATLAS detector

Measurements of differential cross sections of top quark pair production in association with jets by the ATLAS experiment at the LHC are presented. The measurements are performed as functions of the top quark transverse momentum, the transverse momentum of the top quark-antitop quark system and the out-of-plane transverse momentum using data from pp collisions at s√=13 TeV collected by the ATLAS detector at the LHC in 2015 and corresponding to an integrated luminosity of 3.2 fb -1 . The top quark pair events are selected in the lepton (electron or muon) + jets channel. The measured cross sections, which are compared to several predictions, allow a detailed study of top quark production.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2018

Techno-Economic Evaluation of Cellulosic Ethanol Production Based on Pilot Biorefinery Data: a Case Study of Sweet Sorghum Bagasse Processed via L+SScF

Replacing fossil fuels with renewable fuels derived from lignocellulosic biomass can contribute to the mitigation of global warming and the economic development of rural communities. This will require lignocellulosic biofuels to become price competitive with fossil fuels. Techno-economic analyses can provide insights into which parts of the biofuel production process need to be optimized to reduce cost or energy use. Here, we used data obtained from a pilot biorefinery to model a commercial-scale biorefinery that processes lignocellulosic biomass to ethanol, with a focus on the minimum ethanol selling price (MESP). The process utilizes a phosphoric acid-catalyzed pre-treatment of sweet sorghum bagasse followed by liquefaction and simultaneous saccharification and co-fermentation (L+SScF) of hexose and pentose sugars by an engineered Escherichia coli strain. After validating a techno-economic model developed with the SuperPro Designer software for the conversion of sugarcane bagasse to ethanol by comparing it to a published Aspen Plus model, six different scenarios were modeled for sweet sorghum bagasse Under the most optimistic scenario, the ethanol can be produced at a cost close to the energy-equivalent price of gasoline. Aside from an increase in the price of gasoline, the gap between ethanol and gasoline prices could also be bridged by either a decrease in the cost of cellulolytic enzymes or development of value-added products from lignin.

Biofuel↗
DOE OSTI2011

W{gamma} Production and Limits on Anomalous WW{gamma} Couplings in pp Collisions at {radical}(s)=1.96 TeV

We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W({yields}l{nu})+{gamma} production in e{gamma} and {mu}{gamma} final states. Using data corresponding to an integrated luminosity of 4.2 fb{sup -1} collected with the D0 detector at the Fermilab Tevatron Collider, the measured cross section times branching fraction for the process pp{yields}W{gamma}+X{yields}l{nu}{gamma}+X and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WW{gamma} couplings for data from hadron colliders: -0.4<{Delta}{kappa}{sub {gamma}<}0.4 and -0.08<{lambda}{sub {gamma}<}0.07 at the 95% C.L.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗