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Ultrafast gigantic photo-response in (EDO-TTF)2PF6 initiated by 10-fs laser pulses (open access)

Ultrafast gigantic photo-response in (EDO-TTF)2PF6 initiated by 10-fs laser pulses

We photo-exited a charge-ordered organic salt (EDO-TTF)2PF6 with sub-10-fs optical pulses. The photo-induced metallic phase appeared within 80-fs after pumping, characterized by large changes in reflectivity (DELTA R/R~0.8) followed by strong coherent phonon modulation
Date: August 7, 2006
Creator: Schoenlein, Robert William; Itatani, Jiro; Rini, Matteo; Cavalleri, Andrea; Onda, Ken; Ishikawa, Tadahiko et al.
Object Type: Article
System: The UNT Digital Library
Insulator-to-metal transition induced by mid-IR vibrational excitation in a magnetoresistive manganite (open access)

Insulator-to-metal transition induced by mid-IR vibrational excitation in a magnetoresistive manganite

Selective vibrational excitation of insulating Pr0.7Ca0.3MnO3 at 17 ?m triggers a transition to a metallic state. A four order of magnitude drop of the sample resistivity and ultrafast, nanosecond-lived reflectivity changes are observed
Date: August 7, 2006
Creator: Schoenlein, Robert William; Rini, Matteo; Itatani, Jiro; Tomioka, Yasuhide; Tokura, Yoshinori; Schoenlein, Robert W. et al.
Object Type: Article
System: The UNT Digital Library
1,2-HOIQO--A highly versatile 1,2-HOPO analog (open access)

1,2-HOIQO--A highly versatile 1,2-HOPO analog

A cyclic, bidentate hydroxamic acid binding unit based on an isoquinoline scaffold has been utilized for the synthesis of a hexadentate tripodal ligand based on the TREN backbone. This prototype for a new class of multidentate chelators forms mononuclear iron(III) complexes and one-dimensional coordination polymers with lanthanide(III) cations. The latter has been determined by single crystal X-ray analysis of the cerium species. The solid state structure in the monoclinic space group P2{sub 1}/c (C{sub 36}H{sub 34}CeN{sub 7}O{sub 11}, a = 12.341(2){angstrom}, b = 26.649(4){angstrom}, c = 10.621(2){angstrom}, {alpha} = {gamma} = 90{sup o}, {beta} = 96.753(3){sup o}, V = 3468.6(9) {angstrom}{sup 3}, Z = 4) exhibits a trigonal-dodecahedral environment around the cerium cation. The proof of concept for the versatility of the new scaffold has been shown by the modification of the crucial precursor 3-carboxyiso-coumarin through electrophilic aromatic substitutions to yield the corresponding chlorosulfonated and nitrated analogs.
Date: August 7, 2006
Creator: Seitz, Michael; Pluth, Michael D. & Raymond, Kenneth N.
Object Type: Article
System: The UNT Digital Library
Temperature sensitivity of Cu K(alpha) imaging efficiency using a spherical Bragg reflecting crystal (open access)

Temperature sensitivity of Cu K(alpha) imaging efficiency using a spherical Bragg reflecting crystal

The Vulcan laser facility at the Rutherford Appleton Laboratory was used to study the interaction of a 75 J 10 ps, high intensity laser beam with low-mass solid, Cu targets. Two instruments were fielded as diagnostics of the Cu K-shell emission from the targets: A single photon counting CCD spectrometer provided the absolute K{sub {alpha}} yield and a spherically bent Bragg crystal recorded 2D monochromatic images with a spatial resolution of 10 {micro}m. Due to the shifting and broadening of the K{sub {alpha}} spectral lines with increasing temperature, there is a temperature dependence of the crystal collection efficiency. This provides a temperature diagnostic when cross calibrated against a single hit CCD spectrometer, and it affects measurements of the spatial pattern of electron transport. The experimental data showing changing collection efficiency are presented. The results are discussed in light of modeling of the temperature-dependent spectrum of Cu K-shell emission.
Date: August 7, 2006
Creator: Akli, K. U.; Key, M. H.; Chung, H. K.; Hansen, S. B.; Freeman, R. R.; Chen, M. H. et al.
Object Type: Article
System: The UNT Digital Library
Picosecond x-ray absorption spectroscopy of photochemical transient species in solution (open access)

Picosecond x-ray absorption spectroscopy of photochemical transient species in solution

A photoinduced Fe(II) spin crossover reaction in solution is studied with ultrafast x-ray absorption spectroscopy. The iron-nitrogen bond lengthens by 0.21+-0.03 Angstrom in the high-spin transient excited state relative to the ground state.
Date: August 7, 2006
Creator: Schoenlein, Robert William; Khalil, Munira; Marcus, Matthew A.; Smeigh, Amanda L.; McCusker, James K.; Chong, Henry H.W. et al.
Object Type: Article
System: The UNT Digital Library
Remaining Sites Verification Package for the 126-B-3, 184-B Coal Pit Dumping Area, Waste Site Reclassification Form 2005-028 (open access)

Remaining Sites Verification Package for the 126-B-3, 184-B Coal Pit Dumping Area, Waste Site Reclassification Form 2005-028

The 126-B-3 waste site is the former coal storage pit for the 184-B Powerhouse. During demolition operations in the 1970s, the site was used for disposal of demolition debris from 100-B/C Area facilities. The site has been remediated by removing debris and contaminated soils. The results of verification sampling demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: August 7, 2006
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
National Certification Methodology for the Nuclear Weapons Stockpile (open access)

National Certification Methodology for the Nuclear Weapons Stockpile

Lawrence Livermore and Los Alamos National Laboratories have developed a common framework and key elements of a national certification methodology called Quantification of Margins and Uncertainties (QMU). A spectrum from senior managers to weapons designers has been engaged in this activity at the two laboratories for on the order of a year to codify this methodology in an overarching and integrated paper. Following is the certification paper that has evolved. In the process of writing this paper, an important outcome has been the realization that a joint Livermore/Los Alamos workshop on QMU, focusing on clearly identifying and quantifying differences between approaches between the two labs plus developing an even stronger technical foundation on methodology, will be valuable. Later in FY03, such a joint laboratory workshop will be held. One of the outcomes of this workshop will be a new version of this certification paper. A comprehensive approach to certification must include specification of problem scope, development of system baseline models, formulation of standards of performance assessment, and effective procedures for peer review and documentation. This document concentrates on the assessment and peer review aspects of the problem. In addressing these points, a central role is played by a 'watch list' …
Date: August 7, 2006
Creator: Goodwin, B T & Juzaitis, R J
Object Type: Report
System: The UNT Digital Library
Lattice motions from THz phonon-polaritons measured with femtosecond x-ray diffraction (open access)

Lattice motions from THz phonon-polaritons measured with femtosecond x-ray diffraction

We use femtosecond x-ray diffraction to measure the coherent lattice displacements associated with the excitation and propagation of THz phonon polaritons in LiTaO3.
Date: August 7, 2006
Creator: Schoenlein, Robert William; Cavalleri, A.; Wall, S.; Simpson, C.; Statz, E.; Ward, D.W. et al.
Object Type: Article
System: The UNT Digital Library
TANF: A Guide to the New Definitions of What Counts as Work Participation (open access)

TANF: A Guide to the New Definitions of What Counts as Work Participation

None
Date: August 7, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Quarantine and Isolation: Selected Legal Issues Relating to Employment (open access)

Quarantine and Isolation: Selected Legal Issues Relating to Employment

None
Date: August 7, 2006
Creator: unknown
Object Type: Report
System: The UNT Digital Library
A FAMILY OF PEROXO-TITANATE MATERIALS TAILORED FOR OPTIMAL STRONTIUM ANDACTINIDE SORPTION (open access)

A FAMILY OF PEROXO-TITANATE MATERIALS TAILORED FOR OPTIMAL STRONTIUM ANDACTINIDE SORPTION

Achieving global optimization of inorganic sorbent efficacy, as well as tailoring sorbent specificity for target sorbates would facilitate increased wide-spread use of these materials in applications such as producing potable water or nuclear waste treatment. Sodium titanates have long been known as sorbents for radionuclides; {sup 90}Sr and transuranic elements in particular. We have developed a related class of materials, which we refer to as peroxo-titanates: these are sodium titanates or hydrous titanates synthesized in the presence of or treated post-synthesis with hydrogen peroxide. Peroxo-titanates show remarkable and universal improved sorption behavior with respect to separation of actinides and strontium from Savannah River Site (SRS) nuclear waste simulants. Enhancement in sorption kinetics can potentially result in as much as an order of magnitude increase in batch processing throughput. Peroxo-titanates have been produced by three different synthetic routes: post-synthesis peroxide-treatment of a commercially produced monosodium titanate, an aqueous-peroxide synthetic route, and an isopropanol-peroxide synthetic route. The peroxo-titanate materials are characteristically yellow to orange, indicating the presence of protonated or hydrated Ti-peroxo species; and the chemical formula can be generally written as H{sub v}Na{sub w}Ti{sub 2}O{sub 5}-(xH{sub 2}O)[yH{sub z}O{sub 2}] where (v+w) = 2, z = 0-2, and total volatile species accounts …
Date: August 7, 2006
Creator: Hobbs, D
Object Type: Article
System: The UNT Digital Library
Screening of Potential Remediation Methods for the 200-ZP-1 Operable Unit at the Hanford Site (open access)

Screening of Potential Remediation Methods for the 200-ZP-1 Operable Unit at the Hanford Site

A screening-level evaluation of potential remediation methods for application to the contaminants of concern (COC) in the 200-ZP-1 Operable Unit at the Hanford Site was conducted based on the methods outlined in the Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA Interim Final. The scope of this screening was to identify the most promising remediation methods for use in the more detailed analysis of remediation alternatives that will be conducted as part of the full feasibility study. The screening evaluation was conducted for the primary COC (potential major risk drivers). COC with similar properties were grouped for the screening evaluation. The screening evaluation was conducted in two primary steps. The initial screening step evaluated potential remediation methods based on whether they can be effectively applied within the environmental setting of the 200-ZP-1 Operable Unit for the specified contaminants. In the second step, potential remediation methods were screened using scoping calculations to estimate the scale of infrastructure, overall quantities of reagents, and conceptual approach for applying the method for each defined grouping of COC. Based on these estimates, each method was screened with respect to effectiveness, implementability, and relative cost categories of the CERCLA feasibility study screening process defined …
Date: August 7, 2006
Creator: Truex, Michael J.; Nimmons, Michael J.; Johnson, Christian D.; Dresel, P EVAN. & Murray, Christopher J.
Object Type: Report
System: The UNT Digital Library
Gamow-Teller Strength in the A=14 Multiplet: A Challenge to the Shell Model (open access)

Gamow-Teller Strength in the A=14 Multiplet: A Challenge to the Shell Model

A new experimental approach to the famous problem of the anomalously slow Gamow-Teller (GT) transitions in the {beta} decay of the A = 14 multiplet is presented. The GT strength distributions to excited states in {sup 14}C and {sup 14}O was studied in high-resolution (d,{sup 2}He) and ({sup 3}He,t) charge-exchange reactions on {sup 14}N. No-core shell-model (NCSM) calculations capable of reproducing the suppression of the {beta} decays predict a selective excitation of J{sup {pi}} = 2{sup +} states. The experimental confirmation represents a validation of the assumptions about the underlying structure of the {sup 14}N ground state wave function. However, the fragmentation of the GT strength over three 2{sup +} final states remains a fundamental issue not explained by the present NCSM using a 6 {h_bar}{omega} model space, suggesting possibly the need to include cluster structure in these light nuclei in a consistent way.
Date: August 7, 2006
Creator: Negret, A.; Adachi, T.; Barrett, B. R.; Baumer, C.; den Berg, A. V.; Berg, G. et al.
Object Type: Article
System: The UNT Digital Library
MODELING DISPERSION FROM CHEMICALS RELEASED AFTER A TRAIN COLLISION IN GRANITEVILLE, SOUTH CAROLINA (open access)

MODELING DISPERSION FROM CHEMICALS RELEASED AFTER A TRAIN COLLISION IN GRANITEVILLE, SOUTH CAROLINA

The Savannah River National Laboratory's (SRNL) Weather INformation and Display (WIND) System was used to provide meteorological and atmospheric modeling/consequence assessment support to state and local agencies following the collision of two Norfolk Southern freight trains on the morning of January 6, 2005. This collision resulted in the release of several toxic chemicals to the environment, including chlorine. The dense and highly toxic cloud of chlorine gas that formed in the vicinity of the accident was responsible for nine fatalities, and caused injuries to more than five hundred others. Transport model results depicting the forecast path of the ongoing release were made available to emergency managers in the county's Unified Command Center shortly after SRNL received a request for assistance. Support continued over the ensuing two days of the active response. The SRNL also provided weather briefings and transport/consequence assessment model results to responders from South Carolina Department of Health and Environmental Control (SCDHEC), the Savannah River Site's (SRS) Emergency Operations Center (EOC), Department of Energy Headquarters, and hazmat teams dispatched from the SRS. Although model-generated forecast winds used in consequence assessments conducted during the incident were provided at 2-km horizontal grid spacing during the accident response, a high-resolution Regional …
Date: August 7, 2006
Creator: Buckley, R; Chuck Hunter, C; Robert Addis, R & Matt Parker, M
Object Type: Article
System: The UNT Digital Library
Investigation of H2 Concentration and Combustion Instability Effects on the Kinetics of Strained Syngas Flames (open access)

Investigation of H2 Concentration and Combustion Instability Effects on the Kinetics of Strained Syngas Flames

The flame extinction limits of syngas (H{sub 2}-CO) flames were measured using a twin-flame-counter-flow burner. Plots of Extinction limits vs. global stretch rates were generated at different mixture compositions and an extrapolation method was used to calculate the flame extinction limit corresponding to an experimentally unattainable zero-stretch condition. The zero-stretch extinction limit of H{sub 2}-CO mixtures decreases (from rich to lean) with the increase in H{sub 2} concentration in the mixture. The average difference between the measured flame extinction limit and the Le Chatelier's calculation is around {approx} 7%. The measured OH{sup -} chemiluminescent data indicates that regardless of mixture compositions the OH radical concentration reduces (within the experimental uncertainties) to an extinction value prior to the flame extinction. Flame extinction limits of H{sub 2}-CO mixtures measured in a flat-flame burner configuration also show a similar relation. Additionally, the measured laminar flame velocity close to the extinction indicates that regardless of fuel composition the premixed flame of hydrogen fuel blends extinguishes when the mixture laminar flame velocity falls below a critical value. The critical laminar flame velocity at extinction for H{sub 2}-CO premixed flames (measured in the flat flame burner configuration) is found to be 3.77({+-}0.38) cm/s. An externally perturbed …
Date: August 7, 2006
Creator: Choudhuri, Ahsan R.
Object Type: Report
System: The UNT Digital Library
[UNT Trailblazers 2006 Pictorial Directory] (open access)

[UNT Trailblazers 2006 Pictorial Directory]

A document collecting pictures of the UNT Trailblazers now with space next to their portraits for names, contact, and other information about them. There are a few pages with historic information about the alumni group. The back page includes pictures of the alumni from the yearbook when they were enrolled.
Date: August 7, 2006
Creator: University of North Texas. Multicultural Center.
Object Type: Text
System: The UNT Digital Library
[Funeral Program for Wilbur Charles Tyler, August 7, 2006] (open access)

[Funeral Program for Wilbur Charles Tyler, August 7, 2006]

Funeral program for Mr. Wilbur Charles "Little Will" Tyler, born August 15, 1950 and died July 30, 2006. The funeral was held August 7, 2006 at St. Paul Baptist Church, officiated by Rev. Kennith G. Rogers. Funeral arrangements were made through Carter-Taylor-Williams Mortuary, and he was buried in Fort Sam Houston National Cemetery near San Antonio, Texas.
Date: August 7, 2006
Creator: unknown
Object Type: Pamphlet
System: The Portal to Texas History

Ensemble: 2006-08-07 – Opera

Recording of the Monday evening performance of the opera "Die Zauberflöte" (The Magic Flute) at the UNT College of Music Lyric Theatre, as part of the Summer Opera Workshop.
Date: August 7, 2006, 8:00 p.m.
Creator: University of North Texas. Division of Vocal Studies. Opera.
Object Type: Sound
System: The UNT Digital Library
Examining MARC Records as Artifacts That Reflect Metadata Utilization Decisions (open access)

Examining MARC Records as Artifacts That Reflect Metadata Utilization Decisions

Article examining MARC records as artifacts that reflect metadata utilization decisions.
Date: August 7, 2006
Creator: Moen, William E.
Object Type: Article
System: The UNT Digital Library
GQ Lup Ab Visible & Near-Infrared Photometric Analysis (open access)

GQ Lup Ab Visible & Near-Infrared Photometric Analysis

We have re-analyzed archival HST R and I band images and Subaru CH{sub 4}, H, Ks and L{prime} data of the recently discovered planetary mass companion (PMC) GQ Lup Ab. With these we produce the first R and I band photometry of the companion and fit a radius and effective temperature using detailed model atmospheres. We find an effective temperature of 2338 {+-} 100K, and a radius of 0.37 {+-} 0.05R{sub {circle_dot}} and luminosity of log(L/L{sub {circle_dot}}) = -2.43 {+-} 0.07 (at 140pc). Since we fit wavelengths that span most of the emitted radiation from GQ Lup this luminosity estimate is robust, with uncertainty dominated by the distance uncertainty. The radius obtained for 140pc (0.37R{sub {circle_dot}}) is significantly larger than the one originally derived. The mass of the object is much more model-dependent than the radiative properties, but for the GAIA dusty models we find a mass between 9-20 M{sub Jup}, in the range of the brown dwarf and PMC deuterium burning boundary. Assuming a distance of 140pc, observations fit to 1{sigma} the Baraffe evolution model for a {approx} 15 M{sub Jup} brown dwarf. Additionally, the F606W photometric band is significantly overluminous compared to model predictions. Such overluminosity could be …
Date: August 7, 2006
Creator: Marois, C; Macintosh, B & Barman, T
Object Type: Article
System: The UNT Digital Library
FEASIBILITY OF THE AEROSOL-TO-LIQUID PARTICLE EXTRACTION SYSTEM (ALPES) FOR COLLECTION OF VIABLE FRANCISELLA SP. (open access)

FEASIBILITY OF THE AEROSOL-TO-LIQUID PARTICLE EXTRACTION SYSTEM (ALPES) FOR COLLECTION OF VIABLE FRANCISELLA SP.

Several Biowatch monitoring sites in the Houston area have tested positive for Francisella tularensis and there is a need to determine whether natural occurring Francisella-related microorganism(s) may be responsible for these observed positive reactions. The collection, culturing and characterization of Francisella-related natural microorganisms will provide the knowledge base to improve the future selectivity of Biowatch monitoring for Francisella. The aerosol-to-liquid particle extraction system (ALPES) is a high-efficiency, dual mechanism collection system that utilizes a liquid collection medium for capture of airborne microorganisms. Since the viability of microorganisms is preserved better in liquid medium than on air filters, this project was undertaken to determine whether Francisella philomiragia and Francisella tularensis LVS maintain acceptable viability in the continuous liquid recirculation, high direct current voltage and residual ozone concentrations which occur during ALPES operation. Throughout a series of preliminary trial runs with representative gram-negative and gram-positive microorganisms, several design modifications and improvements to the ALPES optimized liquid handling, electrical stability, sampling and overall performance for biological sampling. Initial testing with Francisella philomiragia showed viability was preserved better in PBS buffer than HBSS buffer. Trial runs at starting cell concentrations of 1.8 x 10{sup 6} and 2.5 x 10{sup 4} CFU/L showed less than …
Date: August 7, 2006
Creator: Heitkamp, M.
Object Type: Report
System: The UNT Digital Library
Network-Centric Maritime Radiation Awareness and Interdiction Experiments: C2 Experimentation (open access)

Network-Centric Maritime Radiation Awareness and Interdiction Experiments: C2 Experimentation

The paper addresses technological and operational challenges of developing a global plug-and-play Maritime Domain Security testbed for the Global War on Terrorism mission. This joint NPS-LLNL project is based on the NPS Tactical Network Topology (TNT) composed of long-haul OFDM networks combined with self-forming wireless mesh links to air, surface, ground, and underwater unmanned vehicles. This long-haul network is combined with ultra-wideband (UWB) communications systems for wireless communications in harsh radio propagation channels. LLNL's UWB communication prototypes are designed to overcome shortcomings of the present narrowband communications systems in heavy metallic and constricted corridors inside ships. In the center of our discussion are networking solutions for the Maritime Interdiction Operation (MIO) Experiments in which geographically distributed command centers and subject matter experts collaborate with the Boarding Party in real time to facilitate situational understanding and course of action selection. The most recent experiment conducted via the testbed extension to the Alameda Island exercised several key technologies aimed at improving MIO. These technologies included UWB communications from within the ship to Boarding Party leader sending data files and pictures, advanced radiation detection equipment for search and identification, biometric equipment to record and send fingerprint files to facilitate rapid positive identification of …
Date: August 7, 2006
Creator: Bordetsky, Alex; Dougan, Arden D. & Nekoogar, Faranak
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 108, No. 110, Ed. 1 Monday, August 7, 2006 (open access)

Altus Times (Altus, Okla.), Vol. 108, No. 110, Ed. 1 Monday, August 7, 2006

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: August 7, 2006
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 91, No. 284, Ed. 1 Monday, August 7, 2006 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 91, No. 284, Ed. 1 Monday, August 7, 2006

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: August 7, 2006
Creator: Stone, Greg
Object Type: Newspaper
System: The Gateway to Oklahoma History