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Gasification Plant Cost and Performance Optimization (open access)

Gasification Plant Cost and Performance Optimization

As part of an ongoing effort of the U.S. Department of Energy (DOE) to investigate the feasibility of gasification on a broader level, Nexant, Inc. was contracted to perform a comprehensive study to provide a set of gasification alternatives for consideration by the DOE. Nexant completed the first two tasks (Tasks 1 and 2) of the ''Gasification Plant Cost and Performance Optimization Study'' for the DOE's National Energy Technology Laboratory (NETL) in 2003. These tasks evaluated the use of the E-GAS{trademark} gasification technology (now owned by ConocoPhillips) for the production of power either alone or with polygeneration of industrial grade steam, fuel gas, hydrocarbon liquids, or hydrogen. NETL expanded this effort in Task 3 to evaluate Gas Technology Institute's (GTI) fluidized bed U-GAS{reg_sign} gasifier. The Task 3 study had three main objectives. The first was to examine the application of the gasifier at an industrial application in upstate New York using a Southeastern Ohio coal. The second was to investigate the GTI gasifier in a stand-alone lignite-fueled IGCC power plant application, sited in North Dakota. The final goal was to train NETL personnel in the methods of process design and systems analysis. These objectives were divided into five subtasks. Subtasks …
Date: May 1, 2005
Creator: Tam, Samuel; Nizamoff, Alan; Kramer, Sheldon; Olson, Scott; Lau, Francis; Roberts, Mike et al.
Object Type: Report
System: The UNT Digital Library
Evidence against a charge density wave on Bi(111) (open access)

Evidence against a charge density wave on Bi(111)

The Bi(111) surface was studied by scanning tunneling microscopy (STM), transmission electron microscopy (TEM) and angle-resolved photoemission (ARPES) in order to verify the existence of a recently proposed surface charge density wave (CDW) [Ch. R. Ast and H. Hoechst Phys. Rev. Lett. 90, 016403 (2003)]. The STM and TEM results to not support a CDW scenario at low temperatures. Furthermore, the quasiparticle interference pattern observed in STM confirms the spin-orbit split character of the surface states which prevents the formation of a CDW, even in the case of good nesting. The dispersion of the electronic states observed with ARPES agrees well with earlier findings. In particular, the Fermi contour of the electron pocket at the centre of the surface Brillouin zone is found to have a hexagonal shape. However, no gap opening or other signatures of a CDW phase transition can be found in the temperature-dependent data.
Date: May 1, 2005
Creator: Kim, T. K.; Wells, J.; Kirkegaard, C.; Li, Z.; Hoffmann, S.V.; Gayone, J. E. et al.
Object Type: Article
System: The UNT Digital Library
Incident Energy Dependence of pt Correlations at RHIC (open access)

Incident Energy Dependence of pt Correlations at RHIC

We present results for two-particle transverse momentum correlations, ({Delta}p{sub t,i}{Delta}p{sub t,j}), as a function of event centrality for Au+Au collisions at {radical}s{sub NN} = 20, 62, 130, and 200 GeV at the Relativistic Heavy Ion Collider. We observe correlations decreasing with centrality that are similar at all four incident energies. The correlations multiplied by the multiplicity density increase with incident energy and the centrality dependence may show evidence of processes such as thermalization, jet production, or the saturation of transverse flow. The square root of the correlations divided by the event-wise average transverse momentum per event shows little or no beam energy dependence and generally agrees with previous measurements at the Super Proton Synchrotron.
Date: April 29, 2005
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
System: The UNT Digital Library
Pseudorapidity Asymmetry and Centrality Dependence of Charged Hadron Spectra in d+Au collisions at sqrt(sNN) = 200 GeV (open access)

Pseudorapidity Asymmetry and Centrality Dependence of Charged Hadron Spectra in d+Au collisions at sqrt(sNN) = 200 GeV

The pseudorapidity asymmetry and centrality dependence of charged hadron spectra in d+Au collisions at {radical}s{sub NN} = 200 GeV are presented. The charged particle density at mid-rapidity, its pseudorapidity asymmetry and centrality dependence are reasonably reproduced by a Multi-Phase Transport model, by HIJING, and by the latest calculations in a saturation model. Ratios of transverse momentum spectra between backward and forward pseudorapidity are above unity for p{sub T} below 5 GeV/c. The ratio of central to peripheral spectra in d+Au collisions shows enhancement at 2 < p{sub T} < 6 GeV/c, with a larger effect at backward rapidity than forward rapidity. Our measurements are in qualitative agreement with gluon saturation and in contrast to calculations based on incoherent multiple partonic scatterings.
Date: January 12, 2005
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
System: The UNT Digital Library
Transverse-momentum dependent modification of dynamic texture in central Au+Au collisions at sqrt(sNN) = 200 GeV (open access)

Transverse-momentum dependent modification of dynamic texture in central Au+Au collisions at sqrt(sNN) = 200 GeV

Correlations in the hadron distributions produced in relativistic Au+Au collisions are studied in the discrete wavelet expansion method. The analysis is performed in the space of pseudorapidity (|{eta}| {le} 1) and azimuth (full 2{pi}) in bins of transverse momentum (p{sub t}) from 0.14 {le} p{sub t} {le} 2.1 GeV/c. In peripheral Au+Au collisions a correlation structure ascribed to minijet fragmentation is observed. It evolves with collision centrality and p{sub t} in a way not seen before which suggests strong dissipation of minijet fragmentation in the longitudinally-expanding medium.
Date: January 10, 2005
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
System: The UNT Digital Library
Open Charm Yields in d+Au Collisions at sqrt(sNN) = 200 GeV (open access)

Open Charm Yields in d+Au Collisions at sqrt(sNN) = 200 GeV

Mid-rapidity open charm spectra from direct reconstruction of D{sup 0}({bar D}{sup 0}) {yields} K{sup {-+}} {pi}{sup {+-}} in d+Au collisions and indirect electron/positron measurements via charm semileptonic decays in p+p and d+Au collisions at {radical}s{sub NN} = 200 GeV are reported. The D{sup 0}({bar D}{sup 0}) spectrum covers a transverse momentum (p{sub T}) range of 0.1 < p{sub T} < 3 GeV/c whereas the electron spectra cover a range of 1 < p{sub T} < 4 GeV/c. The electron spectra show approximate binary collision scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at mid-rapidity for open charm production from d+Au collisions at RHIC is d{sigma}{sub c{bar c}}{sup NN}/dy = 0.30 {+-} 0.04 (stat.) {+-} 0.09(syst.) mb. The results are compared to theoretical calculations. Implications for charmonium results in A+A collisions are discussed.
Date: January 7, 2005
Creator: Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Arkhipkin, D. et al.
Object Type: Article
System: The UNT Digital Library
The Hexagon, Volume 96, Number 1, Spring 2005 (open access)

The Hexagon, Volume 96, Number 1, Spring 2005

Quarterly publication of the Alpha Chi Sigma chemistry fraternity containing articles related to chemistry research and the activities of the organization, including local chapters and groups.
Date: Spring 2005
Creator: Alpha Chi Sigma
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

This document comprises the final technical report for atomic collisions research supported by DOE grant No. DE-FG02-87ER13778 from September 1, 2001 through August 31, 2004. The research involved the experimental investigation of excitation and charge-changing processes occurring in ion-atom and ion-molecule collisions. Major emphases of the study were: (1) interference effects resulting from coherent electron emission in H2, (2) production of doubly vacant K-shell (hollow ion) states due to electron correlation, and (3) formation of long-lived metastable states in electron transfer processes. During the period of the grant, this research resulted in 23 publications, 12 invited presentations, and 39 contributed presentations at national and international meetings and other institutions. Brief summaries of the completed research are presented below.
Date: November 25, 2005
Creator: Tanis, John
Object Type: Report
System: The UNT Digital Library
Final Technical Report: DE-FG03-01ER63099/DE-FG02-01ER63099 (open access)

Final Technical Report: DE-FG03-01ER63099/DE-FG02-01ER63099

Organic material contributes {approx}20-50% to the total fine aerosol mass at continental mid-latitudes (Saxena and Hildemann, 1996; Murphy et al., 1998; Peterson and Tyler, 2002; Putaud et al., 2004) and as much as 90% in tropical forested areas (Andreae and Crutzen, 1997; Artaxo et al., 2002). Significant amounts of carbonaceous aerosols are also observed in the free troposphere (Heald et al., 2005). A substantial fraction of the organic component of atmospheric particles consists of water-soluble, possibly multifunctional compounds (Saxena and Hildemann, 1996; Kavouras et al., 1998). It is critical that we understand how organic aerosols and their precursors are transformed in the atmosphere and the dependence of the transformation on the chemical and thermodynamic conditions of the ambient environment: (1) to accurately forecast how changing emissions will impact atmospheric organic aerosol concentrations and properties on the regional to global scale, and (2) to relate atmospheric measurements to sources. A large (but as yet unquantified) fraction of organic aerosol is formed in the atmosphere by precursor gases. In addition, both primary and secondary organic aerosol interact with other gas and aerosol species in the atmosphere so that their properties (i.e., size, hygroscopicity, light absorption and scattering sphere efficiency) can change significantly …
Date: February 23, 2005
Creator: Seinfeld, John H.
Object Type: Report
System: The UNT Digital Library
The Ranger (San Antonio, Tex.), Vol. 79, No. 18, Ed. 1 Friday, March 4, 2005 (open access)

The Ranger (San Antonio, Tex.), Vol. 79, No. 18, Ed. 1 Friday, March 4, 2005

Weekly student newspaper from San Antonio College in San Antonio, Texas that includes campus news along with advertising.
Date: March 4, 2005
Creator: San Antonio College
Object Type: Newspaper
System: The Portal to Texas History
Rediscovery of the Elements: Carl Wilhelm Scheele (open access)

Rediscovery of the Elements: Carl Wilhelm Scheele

Article describing the career and discoveries of Carl Wilhelm Scheele. Tourist information regarding locations important to Scheele's life are visited and discussed.
Date: Spring 2005
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Object Type: Article
System: The UNT Digital Library
Call Number, Volume 64, Number 1, Spring 2005 (open access)

Call Number, Volume 64, Number 1, Spring 2005

Call Number, is the newsletter of the School of Library and Information Sciences, University of North Texas. The periodical contains information about professors, news in the department, and the school's alumni.
Date: 2005
Creator: University of North Texas. School of Library and Information Sciences.
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Atomic-Resolution Observations of Semi-Crystalline IntegranularThin Films in Silicon Nitride (open access)

Atomic-Resolution Observations of Semi-Crystalline IntegranularThin Films in Silicon Nitride

The thin intergranular phase in a silicon nitride (Si3N4)ceramic, which has been regarded for decades as having an entirely amorphous morphology, is shown to have a semi-crystalline structure. Using two different but complementary high-resolution electron microscopy methods, the intergranular atomic structure was directly imaged at the atomic level. These high-resolution images show that the atomic arrangement of the dopand element cerium takes very periodic positions not only along the interface between the intergranular phase and the Si3N4 matrix grains, but it arranges in a semi-crystalline structure that spans the entire width of the intergranular phase between two adjacent matrix grains, in principle connecting the two separate matrix grains. The result will have implications on the approach of understanding the materials properties of ceramics, most significantly on the mechanical properties and the associated computational modeling of the atomic structure of the thin intergranular phase in Si3N4 ceramics.
Date: August 1, 2005
Creator: Ziegler, Alexander; Idrobo, Juan C.; Cinibulk, Michael K.; Kisielowski, Christian; Browning, Nigel D. & Ritchie, Robert O.
Object Type: Article
System: The UNT Digital Library
Sequencing and comparing whole mitochondrial genomes ofanimals (open access)

Sequencing and comparing whole mitochondrial genomes ofanimals

Comparing complete animal mitochondrial genome sequences is becoming increasingly common for phylogenetic reconstruction and as a model for genome evolution. Not only are they much more informative than shorter sequences of individual genes for inferring evolutionary relatedness, but these data also provide sets of genome-level characters, such as the relative arrangements of genes, that can be especially powerful. We describe here the protocols commonly used for physically isolating mtDNA, for amplifying these by PCR or RCA, for cloning,sequencing, assembly, validation, and gene annotation, and for comparing both sequences and gene arrangements. On several topics, we offer general observations based on our experiences to date with determining and comparing complete mtDNA sequences.
Date: April 22, 2005
Creator: Boore, Jeffrey L.; Macey, J. Robert & Medina, Monica
Object Type: Book
System: The UNT Digital Library
You S. A. (San Antonio, Tex.), Vol. 21, No. 1, Ed. 1 Friday, July 1, 2005 (open access)

You S. A. (San Antonio, Tex.), Vol. 21, No. 1, Ed. 1 Friday, July 1, 2005

Newspaper produced by students attending the annual Urban Journalism Workshop at San Antonio College in San Antonio, Texas.
Date: July 1, 2005
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Texas Jewish Post (Fort Worth, Tex.), Vol. 59, No. 45, Ed. 1 Thursday, November 10, 2005 (open access)

Texas Jewish Post (Fort Worth, Tex.), Vol. 59, No. 45, Ed. 1 Thursday, November 10, 2005

Weekly Jewish newspaper from Fort Worth, Texas that includes local, state and national news along with extensive advertising.
Date: November 10, 2005
Creator: Wisch, Rene
Object Type: Newspaper
System: The Portal to Texas History
Assessment of Potential for Ion Driven Fast Ignition (open access)

Assessment of Potential for Ion Driven Fast Ignition

Critical issues and ion beam requirements are explored for fast ignition using ion beams to provide fuel compression using indirect drive and to provide separate short pulse ignition heating using direct drive. Several ion species with different hohlraum geometries are considered for both accelerator-produced and laser-produced ion ignition beams. Ion-driven fast ignition targets are projected to have modestly higher gains than with conventional heavy-ion fusion, and may offer some other advantages for target fabrication and for use of advanced fuels. However, much more analysis and experiments are needed before conclusions can be drawn regarding the feasibility for meeting the ion beam transverse and longitudinal emittances, focal spots, pulse lengths, and target stand-off distances required for ion-driven fast ignition.
Date: May 1, 2005
Creator: Logan, B. Grant; Bangerter, Roger O.; Callahan, Debra A.; Tabak,Max; Roth, Markus; Perkins, L. John et al.
Object Type: Article
System: The UNT Digital Library
Rolling circle amplification of metazoan mitochondrialgenomes (open access)

Rolling circle amplification of metazoan mitochondrialgenomes

Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.
Date: July 31, 2005
Creator: Simison, W. Brian; Lindberg, D. R. & Boore, J. L.
Object Type: Article
System: The UNT Digital Library
Depth profile of uncompensated spins in an exchange bias system (open access)

Depth profile of uncompensated spins in an exchange bias system

We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and antiferromagnet. The new uncompensated magnetization near the interface responds to applied field, while the uncompensated spins in the antiferromagnetic bulk are pinned, thus providing a means to establish exchange bias.
Date: May 17, 2005
Creator: Roy, S.; Fitzsimmons, M.R.; Park, S.; Dorn, M.; Petracic, O.; Roshchin, Igor V. et al.
Object Type: Article
System: The UNT Digital Library
Rediscovery of the Elements: Joseph Priestley (open access)

Rediscovery of the Elements: Joseph Priestley

Article describing the career and discoveries of Joseph Priestley. Tourist information regarding locations important to Priestley's life are visited and discussed.
Date: Summer 2005
Creator: Marshall, James L., 1940- & Marshall, Virginia R.
Object Type: Article
System: The UNT Digital Library
ImSET: Impact of Sector Energy Technologies (open access)

ImSET: Impact of Sector Energy Technologies

This version of the Impact of Sector Energy Technologies (ImSET) model represents the ''next generation'' of the previously developed Visual Basic model (ImBUILD 2.0) that was developed in 2003 to estimate the macroeconomic impacts of energy-efficient technology in buildings. More specifically, a special-purpose version of the 1997 benchmark national Input-Output (I-O) model was designed specifically to estimate the national employment and income effects of the deployment of Office of Energy Efficiency and Renewable Energy (EERE) -developed energy-saving technologies. In comparison with the previous versions of the model, this version allows for more complete and automated analysis of the essential features of energy efficiency investments in buildings, industry, transportation, and the electric power sectors. This version also incorporates improvements in the treatment of operations and maintenance costs, and improves the treatment of financing of investment options. ImSET is also easier to use than extant macroeconomic simulation models and incorporates information developed by each of the EERE offices as part of the requirements of the Government Performance and Results Act.
Date: July 19, 2005
Creator: Roop, Joseph M.; Scott, Michael J. & Schultz, Robert W.
Object Type: Report
System: The UNT Digital Library
Molluscan Evolutionary Genomics (open access)

Molluscan Evolutionary Genomics

In the last 20 years there have been dramatic advances in techniques of high-throughput DNA sequencing, most recently accelerated by the Human Genome Project, a program that has determined the three billion base pair code on which we are based. Now this tremendous capability is being directed at other genome targets that are being sampled across the broad range of life. This opens up opportunities as never before for evolutionary and organismal biologists to address questions of both processes and patterns of organismal change. We stand at the dawn of a new 'modern synthesis' period, paralleling that of the early 20th century when the fledgling field of genetics first identified the underlying basis for Darwin's theory. We must now unite the efforts of systematists, paleontologists, mathematicians, computer programmers, molecular biologists, developmental biologists, and others in the pursuit of discovering what genomics can teach us about the diversity of life. Genome-level sampling for mollusks to date has mostly been limited to mitochondrial genomes and it is likely that these will continue to provide the best targets for broad phylogenetic sampling in the near future. However, we are just beginning to see an inroad into complete nuclear genome sequencing, with several mollusks …
Date: December 1, 2005
Creator: Simison, W. Brian & Boore, Jeffrey L.
Object Type: Report
System: The UNT Digital Library
Yoakum Herald-Times (Yoakum, Tex.), Vol. 113, No. 30, Ed. 1 Wednesday, July 27, 2005 (open access)

Yoakum Herald-Times (Yoakum, Tex.), Vol. 113, No. 30, Ed. 1 Wednesday, July 27, 2005

Weekly newspaper from Yoakum, Texas that includes local, state, and national news along with advertising.
Date: July 27, 2005
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Transcriptome analysis of alfalfa glandular trichomes (open access)

Transcriptome analysis of alfalfa glandular trichomes

Article on the transcriptome analysis of alfalfa glandular trichomes.
Date: April 1, 2005
Creator: Aziz, Naveed; Paiva, Nancy L.; May, Gregory D. & Dixon, R. A.
Object Type: Article
System: The UNT Digital Library