A VUV Photoionization Study of the Combustion-Relevant Reaction of the Phenyl Radical (C6H5) with Propylene (C3H6) in a High Temperature Chemical Reactor (open access)

A VUV Photoionization Study of the Combustion-Relevant Reaction of the Phenyl Radical (C6H5) with Propylene (C3H6) in a High Temperature Chemical Reactor

We studied the reaction of phenyl radicals (C6H5) with propylene (C3H6) exploiting a high temperature chemical reactor under combustion-like conditions (300 Torr, 1,200-1,500 K). The reaction products were probed in a supersonic beam by utilizing tunable vacuum ultraviolet (VUV) radiation from the Advanced Light Source and recording the photoionization efficiency (PIE) curves at mass-to-charge ratios of m/z = 118 (C9H10+) and m/z = 104 (C8H8+). Our results suggest that the methyl and atomic hydrogen losses are the two major reaction pathways with branching ratios of 86 10 percent and 14 10 percent. The isomer distributions were probed by fitting the recorded PIE curves with a linear combination of the PIE curves of the individual C9H10 and C8H8 isomers. Styrene (C6H5C2H3) was found to be the exclusive product contributing to m/z = 104 (C8H8+), whereas 3-phenylpropene, cis-1-phenylpropene, and 2-phenylpropene with branching ratios of 96 4 percent, 3 3 percent, and 1 1 percent could account for signal at m/z = 118 (C9H10+). Although searched for carefully, no evidence of the bicyclic indane molecule could be provided. The reaction mechanisms and branching ratios are explained in terms of electronic structure calculations nicely agreeing with a recent crossed molecular beam study on this …
Date: February 22, 2012
Creator: Manoa, University of Hawaii at; Laboratories, Sandia National; Zhang, Fangtong; Kaiser, Ralf I.; Golan, Amir; Ahmed, Musahid et al.
Object Type: Article
System: The UNT Digital Library
Award Nomination Information for Lawrence Livermore National Laboratory SkillSoft Perspectives Conference 2012 (open access)

Award Nomination Information for Lawrence Livermore National Laboratory SkillSoft Perspectives Conference 2012

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Date: February 22, 2012
Creator: Positeri, L A & Molyneaux, B R
Object Type: Article
System: The UNT Digital Library
Facts About XLDB-2011 (open access)

Facts About XLDB-2011

This note provides details of the 5th Extremely Large Databases Conference and Invitational Workshop that were held in 2011 on 18-19 October and 20 October, respectively, at the SLAC National Accelerator Laboratory in Menlo Park, California. The main goals of the conference were: (1) Encourage and accelerate the exchange of ideas between users trying to build extremely large databases worldwide and database solution providers; (2) Share lessons, trends, innovations, and challenges related to building extremely large databases; (3) Facilitate the development and growth of practical technologies for extremely large databases; and (4) Strengthen, expand, and engage the XLDB community.
Date: February 22, 2012
Creator: Becla, Jacek; Lim, Kian-Tat & Wang, Daniel L.
Object Type: Article
System: The UNT Digital Library
Alternative Energy for Higher Education (open access)

Alternative Energy for Higher Education

This project provides educational opportunities creating both a teaching facility and center for public outreach. The facility is the largest solar array in Nebraska. It was designed to allow students to experience a variety of technologies and provide the public with opportunities for exposure to the implementation of an alternative energy installation designed for an urban setting. The project integrates products from 5 panel manufacturers (including monocrystalline, polycrystalline and thin film technologies) mounted on both fixed and tracking structures. The facility uses both micro and high power inverters. The majority of the system was constructed to serve as an outdoor classroom where panels can be monitored, tested, removed and replaced by students. As an educational facility it primarily serves students in the Creighton University and Metropolitan Community College, but it also provides broader educational opportunities. The project includes a real-time “dashboard” and a historical database of the output of individual inverters and the corresponding meteorological data for researcher and student use. This allows the evaluation of both panel types and the feasibility of installation types in a region of the country subject to significant temperature, wind and precipitation variation.
Date: February 22, 2012
Creator: Michael Cherney, PhD
Object Type: Text
System: The UNT Digital Library
Cascade Reverse Osmosis Air Conditioning System (open access)

Cascade Reverse Osmosis Air Conditioning System

Advanced Research Projects Agency-Energy project sheet summarizing general information about the Building Energy Efficiency Through Innovative Thermodevices (BEETIT) program including critical needs, innovation and advantages, impacts, and contact information. This sheet discusses air conditioning that has increased electrical efficiency as part of the "Cascade Reverse Osmosis and the Absorption Osmosis Cycle" project.
Date: February 22, 2012
Creator: Batelle Memorial Institute
Object Type: Text
System: The UNT Digital Library
Magnetic Fields in Population III Star Formation (open access)

Magnetic Fields in Population III Star Formation

We study the buildup of magnetic fields during the formation of Population III star-forming regions, by conducting cosmological simulations from realistic initial conditions and varying the Jeans resolution. To investigate this in detail, we start simulations from identical initial conditions, mandating 16, 32 and 64 zones per Jeans length, and studied the variation in their magnetic field amplification. We find that, while compression results in some amplification, turbulent velocity fluctuations driven by the collapse can further amplify an initially weak seed field via dynamo action, provided there is sufficient numerical resolution to capture vortical motions (we find this requirement to be 64 zones per Jeans length, slightly larger than, but consistent with previous work run with more idealized collapse scenarios). We explore saturation of amplification of the magnetic field, which could potentially become dynamically important in subsequent, fully-resolved calculations. We have also identified a relatively surprising phenomena that is purely hydrodynamic: the higher-resolved simulations possess substantially different characteristics, including higher infall-velocity, increased temperatures inside 1000 AU, and decreased molecular hydrogen content in the innermost region. Furthermore, we find that disk formation is suppressed in higher-resolution calculations, at least at the times that we can follow the calculation. We discuss the …
Date: February 22, 2012
Creator: Turk, Matthew J.; Oishi, Jeffrey S.; Abel, Tom & Bryan, Greg
Object Type: Article
System: The UNT Digital Library
Study of charmonium resonances in the gg -> K0SK pi- and gg -> K K-pi pi-pi0 processes (open access)

Study of charmonium resonances in the gg -> K0SK pi- and gg -> K K-pi pi-pi0 processes

This thesis reports the analysis of the e{sup +}e{sup -} {yields} e{sup +}e{sup -}K{sub S}{sup 0}K{sup {+-}}{pi}{sup {-+}} and e{sup +}e{sup -} {yields} e{sup +}e{sup -}K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup 0} processes using the final dataset of the BABAR experiment located at the SLAC National Accelerator Laboratory. From previous measurements, the K{sub S}{sup 0}K{sup {+-}}{pi}{sup {-+}} final state is known to show a clear signal from the {eta}{sub c}(2S) particle. This c{bar c} state escaped detection for almost twenty years and its properties are still not well established on the experimental ground, while accurate predictions exist on the theoretical side. The e{sup +}e{sup -} {yields} e{sup +}e{sup -}K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup 0} process is first studied in this thesis. An accurate determination of the {eta}{sub c}(2S) properties is obtained in the K{sub S}{sup 0}K{sup {+-}}{pi}{sup {-+}} decay mode. We also report the first observation of {eta}{sub c}(2S) and other charmonium states to the K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup 0} final state. The results of this thesis have been published in Physical Review D, and will be useful to test theoretical models describing the charmonium system. The thesis is organized in four chapters. The first one gives a brief introduction …
Date: February 22, 2012
Creator: Biassoni, Pietro & /U. Milan, Dept. Phys.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Photon Strength and the Low-Energy Enhancement (open access)

Photon Strength and the Low-Energy Enhancement

The ability of atomic nuclei to emit and absorb photons with energy E{sub {gamma}} is known as the photon strength function f(E{sub {gamma}}). It has direct relevance to astrophysical element formation via neutron capture processes due to its central role in nuclear reactions. Studies of f(E{sub {gamma}}) have benefited from a wealth of data collected in neutron capture and direct reactions but also from newly commissioned inelastic photon scattering facilities. The majority of these experimental methods, however, rely on the use of models because measured {gamma}-ray spectra are simultaneously sensitive to both the nuclear level density and f(E{sub {gamma}}). As excitation energy increases towards the particle separation energies, the level density increases rapidly, creating the quasi-continuum. Nuclear properties in this excitation energy region are best characterized using statistical quantities, such as f(E{sub {gamma}}). A point of contention in studies of the quasi-continuum has been an unexpected and unexplained increase in f(E{sub {gamma}}) at low {gamma}-ray energies (i.e. below E{sub {gamma}} {approx}3 MeV) in a subset of light-to-medium mass nuclei. Ideally, a new model-independent experimental technique is required to address questions regarding the existence and origin of this low-energy enhancement in f(E{sub {gamma}}). Here such a model-independent approach is presented for …
Date: February 22, 2012
Creator: Wiedeking, M; Bernstein, L A; Krticka, M; Bleuel, D L; Allmond, J M; Basunia, M S et al.
Object Type: Article
System: The UNT Digital Library
Components of the dilepton continuum in Pb+Pb collisions at sqrt s = 2.76 TeV (open access)

Components of the dilepton continuum in Pb+Pb collisions at sqrt s = 2.76 TeV

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Date: February 22, 2012
Creator: Vogt, R; Shukla, P & Kumar, V
Object Type: Article
System: The UNT Digital Library
GADOLINIUM OXALATE SOLUBILITY MEASUREMENTS IN NITRIC ACID SOLUTIONS (open access)

GADOLINIUM OXALATE SOLUBILITY MEASUREMENTS IN NITRIC ACID SOLUTIONS

HB-Line will begin processing Pu solutions during FY2012 that will involve the recovery of Pu using oxalate precipitation and filtration. After the precipitation and filtration processes, the filtrate solution will be transferred from HB-Line to H-Canyon. The presence of excess oxalate and unfiltered Pu oxalate solids in these solutions create a criticality safety issue if they are sent to H-Canyon without controls in H-Canyon. One approach involves H-Canyon receiving the filtrate solution into a tank that is poisoned with soluble gadolinium (Gd). Decomposition of the oxalate will occur within a subsequent H-Canyon vessel. The receipt of excess oxalate into the H-Canyon receipt tanks has the potential to precipitate a portion of the Gd poison in the receipt tanks. Because the amount of Gd in solution determines the maximum amount of Pu solids that H-Canyon can receive, H-Canyon Engineering requested that SRNL determine the solubility of Gd in aqueous solutions of 4-10 M nitric acid (HNO{sub 3}), 4-12 g/L Gd, and 0.15-0.25 M oxalic acid (H{sub 2}C{sub 2}O{sub 4}) at 25 C. The target soluble Gd concentration is 6 g/L. The data indicate that the target can be achieved above 6 M HNO{sub 3} and below 0.25 M H{sub 2}C{sub 2}O{sub …
Date: February 22, 2012
Creator: Pierce, R.
Object Type: Report
System: The UNT Digital Library