7 Matching Results

Search Results

Advanced search parameters have been applied.

Grid-based methods for diatomic quantum scattering problems II: Time-dependent treatment of single- and two-photon ionization of H2+

Description: The time-dependent Schr\"odinger equation for H2+ in a time-varying electromagnetic field is solved in the fixed-nuclei approximation using a previously developed finite-element/ discrete variable representation in prolate spheroidal coordinates. Amplitudes for single- and two-photon ionization are obtained using the method of exterior complex scaling to effectively propagate the field-free solutions from the end of the radiation pulse to infinite times. Cross sections are presented for one-and two-photon ionization for both parallel and perpendicular polarization of the photon field, as well as photoelectron angular distributions for two-photon ionization.
Date: April 20, 2009
Creator: Rescigno, Thomas N.; Tao, L. & McCurdy, C.W.
Partner: UNT Libraries Government Documents Department

Biological Conversion of Sugars to Hydrocarbons Technology Pathway

Description: This technology pathway case investigates the biological conversion of biomass-derived sugars to hydrocarbon biofuels, utilizing data from recent literature references and information consistent with recent pilot-scale demonstrations at NREL. Technical barriers and key research needs have been identified that should be pursued for the pathway to become competitive with petroleum-derived gasoline-, diesel-, and jet-range hydrocarbon blendstocks.
Date: March 1, 2013
Creator: Davis, R.; Biddy, M.; Tan, E.; Tao, L. & Jones, S.
Partner: UNT Libraries Government Documents Department

Process Design and Economics for Biochemical Conversion of Lignocellulosic Biomass to Ethanol: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

Description: This report describes one potential biochemical ethanol conversion process, conceptually based upon core conversion and process integration research at NREL. The overarching process design converts corn stover to ethanol by dilute-acid pretreatment, enzymatic saccharification, and co-fermentation. Building on design reports published in 2002 and 1999, NREL, together with the subcontractor Harris Group Inc., performed a complete review of the process design and economic model for the biomass-to-ethanol process. This update reflects NREL's current vision of the biochemical ethanol process and includes the latest research in the conversion areas (pretreatment, conditioning, saccharification, and fermentation), optimizations in product recovery, and our latest understanding of the ethanol plant's back end (wastewater and utilities). The conceptual design presented here reports ethanol production economics as determined by 2012 conversion targets and 'nth-plant' project costs and financing. For the biorefinery described here, processing 2,205 dry ton/day at 76% theoretical ethanol yield (79 gal/dry ton), the ethanol selling price is $2.15/gal in 2007$.
Date: March 1, 2011
Creator: Humbird, D.; Davis, R.; Tao, L.; Kinchin, C.; Hsu, D.; Aden, A. et al.
Partner: UNT Libraries Government Documents Department

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons

Description: This report describes one potential conversion process to hydrocarbon products by way of biological conversion of lingnocellulosic-dervied sugars. The process design converts biomass to a hydrocarbon intermediate, a free fatty acid, using dilute-acid pretreatement, enzymatic saccharification, and bioconversion. Ancillary areas--feed handling, hydrolysate conditioning, product recovery and upgrading (hydrotreating) to a final blendstock material, wastewater treatment, lignin combusion, and utilities--are also included in the design.
Date: October 1, 2013
Creator: Davis, R.; Tao, L.; Tan, E. C. D.; Biddy, M. J.; Beckham, G. T.; Scarlata, C. et al.
Partner: UNT Libraries Government Documents Department

Measurements of the Nucleon Form-Factors at Large Momentum Transfers

Description: New measurements of the electric GE(Q2) and magnetic GM(Q2) form factors of the nucleons are reported. The proton data cover the Q2 range from 1.75 to 8.83 (GeV/c)2 and the neutron data from 1.75 to 4.00 (GeV/c)2, more than doubling the range of previous data. Scaled by the dipole fit, GD(Q2), the results forGMp(Q2) /¿pGD(Q2) decrease smoothly from 1.05 to 0.92, while GEp(Q2)/GD(Q2)is consistent with unity. The preliminary results for GMn(Q2) /¿nGD(Q2) are consistent with unity, while GEn is consistent with zero at all values of Q2.
Date: July 26, 1992
Creator: Andivahis, L; Bosted, Peter; Lung, Allison; Stuart, Linda; Alster, Jonas; Arnold, Raymond et al.
Partner: UNT Libraries Government Documents Department

Measurements of the nucleon form factors at large momentum transfers

Description: New measurements of the electric G[sub E](Q[sup 2]) and magnetic G[sub M](Q[sup 2]) form factors of the nucleons are reported. The proton data cover the Q[sup 2] range from 1.75 to 8.83 (GeV/c)[sup 2] and the neutron data from 1.75 to 4.00 (GeV/c)[sup 2], more than doubling the range of previous data. Scaled by the dipole fit, G[sub D](Q[sup 2]), the results for G[sub Mp](Q[sup 2])/[mu][sub p]G[sub D](Q[sup 2]) decrease smoothly from 1.05 to 0.92, while G[sub Ep](Q[sup 2])/G[sub D](Q[sup 2]) is consistent with unity. The preliminary results for Gm.(Q2)1 GD(Q2) consistent with unity, while F[sub En][sup 2] is consistent with zero at all values of Q[sup 2]. Comparisons are made to QCD Sum Rule, diquark, constituent quark, and VMD models, none of which agree with all of the new data.
Date: December 1, 1992
Creator: Andivahis, L.; Bosted, P.; Lung, A.; Arnold, R.; Keppel, C.; Rock, S. et al.
Partner: UNT Libraries Government Documents Department

Measurements of the nucleon form factors at large momentum transfers

Description: New measurements of the electric G{sub E}(Q{sup 2}) and magnetic G{sub M}(Q{sup 2}) form factors of the nucleons are reported. The proton data cover the Q{sup 2} range from 1.75 to 8.83 (GeV/c){sup 2} and the neutron data from 1.75 to 4.00 (GeV/c){sup 2}, more than doubling the range of previous data. Scaled by the dipole fit, G{sub D}(Q{sup 2}), the results for G{sub Mp}(Q{sup 2})/{mu}{sub p}G{sub D}(Q{sup 2}) decrease smoothly from 1.05 to 0.92, while G{sub Ep}(Q{sup 2})/G{sub D}(Q{sup 2}) is consistent with unity. The preliminary results for Gm.(Q2)1 GD(Q2) consistent with unity, while F{sub En}{sup 2} is consistent with zero at all values of Q{sup 2}. Comparisons are made to QCD Sum Rule, diquark, constituent quark, and VMD models, none of which agree with all of the new data.
Date: December 1, 1992
Creator: Andivahis, L.; Bosted, P.; Lung, A.; Arnold, R.; Keppel, C.; Rock, S. et al.
Partner: UNT Libraries Government Documents Department