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A QSAR for the Mutagenic Potencies of Twelve 2-Amino-trimethylimidazopyridine Isomers: Structural, Quantum Chemical,and Hydropathic Factors (open access)

A QSAR for the Mutagenic Potencies of Twelve 2-Amino-trimethylimidazopyridine Isomers: Structural, Quantum Chemical,and Hydropathic Factors

An isomeric series of heterocyclic amines related to one found in heated muscle meats was investigated for properties that predict their measured mutagenic potency. Eleven of the 12 possible 2-amino-trimethylimidazopyridine (TMIP) isomers were tested for mutagenic potency in the Ames/Salmonella test with bacterial strain TA98, and resulted in a 600-fold range in potency. Structural, quantum chemical and hydropathic data were calculated on the parent molecules and the corresponding nitrenium ions of all of the tested isomers to establish models for predicting the potency of the unknown isomer. The regression model accounting for the largest fraction of the total variance in mutagenic potency contains four predictor variables: dipole moment, a measure of the gap between amine LUMO and HOMO energies, percent hydrophilic surface, and energy of amine LUMO. The most important determinants of high mutagenic potency in these amines are: (1) a small dipole moment, (2) the combination of b-face ring fusion and N3-methyl group, and (3) a lower calculated energy of the {pi} electron system. Based on predicted potency from the average of five models, the isomer not yet synthesized and tested is expected to have a mutagenic potency of 0.84 revertants/{micro}g in test strain TA98.
Date: April 23, 2005
Creator: Knize, M G; Hatch, F T; Tanga, M J; Lau, E V & Colvin, M E
Object Type: Article
System: The UNT Digital Library
FROM THE ISR TO RHIC - MEASUREMENTS OF HARD-SCATTERING AND JETS USING INCLUSIVE SINGLE PARTICLE PRODUCTION AND 2-PARTICLE CORRELATIONS. (open access)

FROM THE ISR TO RHIC - MEASUREMENTS OF HARD-SCATTERING AND JETS USING INCLUSIVE SINGLE PARTICLE PRODUCTION AND 2-PARTICLE CORRELATIONS.

Hard scattering in p-p collisions, discovered at the CERN ISR in 1972 by the method of leading particles, proved that the partons of Deeply Inelastic Scattering strongly interacted with each other. Further ISR measurements utilizing inclusive single or pairs of hadrons established that high p{sub T} particles are produced from states with two roughly back-to-back jets which are the result of scattering of constituents of the nucleons as described by Quantum Chromodynamics (QCD), which was developed during the course of these measurements. These techniques, which are the only practical method to study hard-scattering and jet phenomena in Au+Au central collisions at RHIC energies, are reviewed, as an introduction to present RHIC measurements.
Date: April 23, 2005
Creator: Tannenbaum, M. J.
Object Type: Article
System: The UNT Digital Library
Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data (open access)

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high …
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Object Type: Text
System: The UNT Digital Library
Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data (open access)

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high …
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Object Type: Report
System: The UNT Digital Library
Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data (open access)

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high …
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Object Type: Report
System: The UNT Digital Library
UXO Engineering Design. Technical Specification and ConceptualDesign (open access)

UXO Engineering Design. Technical Specification and ConceptualDesign

The design and fabrication of the UXO detector has numerous challenges and is an important component to the success of this study. This section describes the overall engineering approach, as well as some of the technical details that brought us to the present design. In general, an array of sensor coils is measuring the signal generated by the UXO object in response to a stimulation provided by the driver coil. The information related to the location, shape and properties of the object is derived from the analysis of the measured data. Each sensor coil is instrumented with a waveform digitizer operating at a nominal digitization rate of 100 kSamples per second. The sensor coils record both the large transient pulse of the driver coil and the UXO object response pulse. The latter is smaller in amplitude and must be extracted from the large transient signal. The resolution required is 16 bits over a dynamic range of at least 140 dB. The useful signal bandwidth of the application extends from DC to 40 kHz. The low distortion of each component is crucial in order to maintain an excellent linearity over the full dynamic range and to minimize the calibration procedure. The …
Date: April 23, 2005
Creator: Beche, J-F.; Doolittle, L.; Greer, J.; Lafever, R.; Radding, Z.; Ratti, A. et al.
Object Type: Report
System: The UNT Digital Library
The Void Specification (open access)

The Void Specification

The purpose of this memo is to explore more fully the allowable void specification, in part to make it clearer to those doing the day-to-day evaluation and in part to help me understand the ramifications. A simulation of voids in a Be shell is used to support my understanding of Haan's analysis. The key results showing allowable void diameter as a function of void fraction are shown in Figure 6 (p. 8). What is important here is that generally in ''good'' samples we only see small voids, perhaps at most a few tenths of a {micro}m in size. For this void size the shells can be underdense by as much as 10% and still meet the 1 part in 10{sup 4} spec (though there may be other issues with reduced density).
Date: April 23, 2005
Creator: Cook, B
Object Type: Report
System: The UNT Digital Library
Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis (open access)

Air to Blood Distribution of Volatile Organic Compounds: A Linear Free Energy Analysis

Article on air to blood distribution of volatile organic compounds and a linear free energy analysis.
Date: April 23, 2005
Creator: Abraham, M. H. (Michael H.); Ibrahim, Adam & Acree, William E. (William Eugene)
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 84, No. 140, Ed. 1 Saturday, April 23, 2005 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 84, No. 140, Ed. 1 Saturday, April 23, 2005

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: April 23, 2005
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History

[Miguel Harth Bedoya]

Conductor Miguel Harth Bedoya is seen holding an award in his right hand as he sits behind a table. He is wearing a white tuxedo with a multicolored bowtie.
Date: April 23, 2005
Creator: Castillo, José L.
Object Type: Photograph
System: The Portal to Texas History

[Miguel Harth Bedoya shakes the hand of a musician]

Conductor Miguel Harth Bedoya shakes the hand of violinist. Behind him another violinist is wearing an elaborate headdress.
Date: April 23, 2005
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Conductor Harth Bedoya with an orchestra]

Photograph of Peruvian conductor Harth Bedoya talking in front of an orchestra.
Date: April 23, 2005
Creator: Castillo, José L.
Object Type: Photograph
System: The Portal to Texas History
Perry Daily Journal (Perry, Okla.), Vol. 112, No. 80, Ed. 1 Saturday, April 23, 2005 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 112, No. 80, Ed. 1 Saturday, April 23, 2005

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: April 23, 2005
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History