Comprehensive chemical kinetic modeling of the oxidation of C8 and larger n-alkanes and 2-methylalkanes (open access)

Comprehensive chemical kinetic modeling of the oxidation of C8 and larger n-alkanes and 2-methylalkanes

Conventional petroleum jet and diesel fuels, as well as alternative Fischer-Tropsch (FT) fuels and hydrotreated renewable jet (HRJ) fuels, contain high molecular weight lightly branched alkanes (i.e., methylalkanes) and straight chain alkanes (n-alkanes). Improving the combustion of these fuels in practical applications requires a fundamental understanding of large hydrocarbon combustion chemistry. This research project presents a detailed and reduced chemical kinetic mechanism for singly methylated iso-alkanes (i.e., 2-methylalkanes) ranging from C{sub 8} to C{sub 20}. The mechanism also includes an updated version of our previously published C{sub 8} to C{sub 16} n-alkanes model. The complete detailed mechanism contains approximately 7,200 species 31,400 reactions. The proposed model is validated against new experimental data from a variety of fundamental combustion devices including premixed and nonpremixed flames, perfectly stirred reactors and shock tubes. This new model is used to show how the presence of a methyl branch affects important combustion properties such as laminar flame propagation, ignition, and species formation.
Date: March 16, 2011
Creator: Sarathy, S. M.; Westbrook, C. K.; Pitz, W. J.; Mehl, M.; Togbe, C.; Dagaut, P. et al.
System: The UNT Digital Library
The National Ignition Facility: The Path to a Carbon-Free Energy Future (open access)

The National Ignition Facility: The Path to a Carbon-Free Energy Future

The National Ignition Facility (NIF), the world's largest and most energetic laser system, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF will enable exploration of scientific problems in national strategic security, basic science and fusion energy. One of the early NIF goals centers on achieving laboratory-scale thermonuclear ignition and energy gain, demonstrating the feasibility of laser fusion as a viable source of clean, carbon-free energy. This talk will discuss the precision technology and engineering challenges of building the NIF and those we must overcome to make fusion energy a commercial reality.
Date: March 16, 2011
Creator: Stolz, C J
System: The UNT Digital Library
Beam Transport in a Compact Dielectric Wall Accelerator for Proton Therapy (open access)

Beam Transport in a Compact Dielectric Wall Accelerator for Proton Therapy

To attain the highest accelerating gradient in the compact dielectric wall (DWA) accelerator, the DWA will be operated in the 'virtual' traveling mode with potentially non-uniform and time-dependent axial accelerating field profiles, especially near the DWA entrance and exit, which makes beam transport challenging. We have established a baseline transport case without using any external lenses. Results of simulations using the 3-D, EM PIC code, LSP indicate that the DWA transport performance meets the medical specifications for proton treatment. Sensitivity of the transport performance to Blumlein block failure will be presented.
Date: March 16, 2011
Creator: Chen, Y.; Caporaso, G.; Blackfield, D.; Nelson, S. D. & Poole, B.
System: The UNT Digital Library
Natural-Synthetic Hybrid Polymers Developed via Electrospinning: The Effect of PET in Chitosan/Starch System (open access)

Natural-Synthetic Hybrid Polymers Developed via Electrospinning: The Effect of PET in Chitosan/Starch System

Paper discusses the results of studying the structural and thermophysical properties of chitosan + starch + poly(ethylene terephthalate) (Ch + S + PET) fibers developed via electrospinning.
Date: March 16, 2011
Creator: Espíndola-González, Adolfo; Martinez-Hernandez, Ana Laura; Fernández-Escobar, Francisco; Castaño, Victor M.; Brostow, Witold, 1934-; Datashvili, Tea et al.
System: The UNT Digital Library