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Enterprise Architecture: Leadership Remains Key to Establishing and Leveraging Architectures for Organizational Transformation (open access)

Enterprise Architecture: Leadership Remains Key to Establishing and Leveraging Architectures for Organizational Transformation

A letter report issued by the Government Accountability Office with an abstract that begins "A well-defined enterprise architecture is an essential tool for leveraging information technology (IT) to transform business and mission operations. GAO's experience has shown that attempting to modernize and evolve IT environments without an architecture to guide and constrain investments results in operations and systems that are duplicative, not well integrated, costly to maintain, and ineffective in supporting mission goals. In light of the importance of enterprise architectures, GAO developed a five stage architecture management maturity framework that defines what needs to be done to effectively manage an architecture program. Under GAO's framework, a fully mature architecture program is one that satisfies all elements of all stages of the framework. As agreed, GAO's objective was to determine the status of major federal department and agency enterprise architecture efforts."
Date: August 14, 2006
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields (open access)

SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

Magnetic resonance imaging (MRI) has developed into a powerful clinical tool for imaging the human body (1). This technique is based on nuclear magnetic resonance (NMR) of protons (2, 3) in a static magnetic field B{sub 0}. An applied radiofrequency pulse causes the protons to precess about B{sub 0} at their Larmor frequency {nu}{sub 0} = ({gamma}/2{pi})B{sub 0}, where {gamma} is the gyromagnetic ratio; {gamma}/2{pi} = 42.58 MHz/tesla. The precessing protons generate an oscillating magnetic field and hence a voltage in a nearby coil that is amplified and recorded. The application of three-dimensional magnetic field gradients specifies a unique magnetic field and thus an NMR frequency in each voxel of the subject, so that with appropriate encoding of the signals one can acquire a complete image (4). Most clinical MRI systems involve magnetic fields generated by superconducting magnets, and the current trend is to higher magnetic fields than the widely used 1.5-T systems (5). Nonetheless, there is ongoing interest in the development of less expensive imagers operating at lower fields. Commercially available 0.2-T systems based on permanent magnets offer both lower cost and a more open access than their higher-field counterparts, at the expense of signal-to-noise-ratio (SNR) and spatial resolution. …
Date: August 14, 2006
Creator: Moessle, Michael; Hatridge, Michael & Clarke, John
Object Type: Article
System: The UNT Digital Library
Holographic optical elements for the extreme-ultravioletregime (open access)

Holographic optical elements for the extreme-ultravioletregime

As the development of extreme ultraviolet (EUV) lithography progresses, interest grows in the extension of traditional optical components to the EUV regime. The strong absorption of EUV by most materials and its extremely short wavelength, however, makes it very difficult to implement many components that are commonplace in the longer wavelength regimes. One such component is the diffractive optical element used, for example, in illumination systems to efficiently generate modified pupil fills. Here we demonstrate the fabrication and characterization of EUV binary phase-only computer-generated holograms allowing arbitrary far-field diffraction patterns to be generated.
Date: August 14, 2006
Creator: Naulleau, Patrick P.; Salmassi, Farhad; Gullikson, Eric M. & Anderson, Erik H.
Object Type: Article
System: The UNT Digital Library
Detecting the limits of regulatory element conservation anddivergence estimation using pairwise and multiple alignments (open access)

Detecting the limits of regulatory element conservation anddivergence estimation using pairwise and multiple alignments

Background: Molecular evolutionary studies of noncodingsequences rely on multiple alignments. Yet how multiple alignmentaccuracy varies across sequence types, tree topologies, divergences andtools, and further how this variation impacts specific inferences,remains unclear. Results: Here we develop a molecular evolutionsimulation platform, CisEvolver, with models of background noncoding andtranscription factor binding site evolution, and use simulated alignmentsto systematically examine multiple alignment accuracy and its impact ontwo key molecular evolutionary inferences: transcription factor bindingsite conservation and divergence estimation. We find that the accuracy ofmultiple alignments is determined almost exclusively by the pairwisedivergence distance of the two most diverged species and that additionalspecies have a negligible influence on alignment accuracy. Conservedtranscription factor binding sites align better than surroundingnoncoding DNA yet are often found to be misaligned at relatively shortdivergence distances, such that studies of binding site gain and losscould easily be confounded by alignment error. Divergence estimates frommultiple alignments tend to be overestimated at short divergencedistances but reach a tool specific divergence at which they cease toincrease, leading to underestimation at long divergences. Our moststriking finding was that overall alignment accuracy, binding sitealignment accuracy and divergence estimation accuracy vary greatly acrossbranches in a tree and are most accurate for terminal branches connectingsister taxa and least …
Date: August 14, 2006
Creator: Pollard, Daniel A.; Moses, Alan M.; Iyer, Venky N. & Eisen,Michael B.
Object Type: Article
System: The UNT Digital Library
Development of a CO2 Sequestration Module by Integrating Mineral Activation and Aqueous Carbonation (open access)

Development of a CO2 Sequestration Module by Integrating Mineral Activation and Aqueous Carbonation

Mineral carbonation is a promising concept for permanent CO{sub 2} sequestration due to the vast natural abundance of the raw materials and the permanent storage of CO{sub 2} in solid form as carbonates. The sequestration of CO{sub 2} through the employment of magnesium silicates--olivine and serpentine--is beyond the proof of concept stage. For the work done in this project, serpentine was chosen as the feedstock mineral due to its abundance and availability. Although the reactivity of olivine is greater than that of serpentine, physical and chemical treatments have been shown to increase greatly the reactivity of serpentine. The primary drawback to mineral carbonation is reaction kinetics. To accelerate the carbonation, aqueous processes are preferred, where the minerals are first dissolved in solution. In aqueous carbonation, the key step is the dissolution rate of the mineral, where the mineral dissolution reaction is likely to be surface-controlled. The relatively low reactivity of serpentine has warranted research into physical and chemical treatments that have been shown to greatly increase its reactivity. The use of sulfuric acid as an accelerating medium for the removal of magnesium from serpentine has been investigated. To accelerate the dissolution process, the mineral can be ground to very fine …
Date: August 14, 2006
Creator: Alexander, George; Aksoy, Parvana; Andresen, John; Maroto-Valer, Mercedes & Schobert, Harold
Object Type: Report
System: The UNT Digital Library

[Woman placing cardboard sign into group of vegetables]

Photograph of a lady placing a price sign on a variety of vegetables at a farmers market. There are two cargo trucks parked behind the lady.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Woman placing vegetables in piles]

Photograph of a woman arranging vegetables at a farmers market. There are several cardboard signs shown on the vegetables and cloves of garlic are visible hanging from the roof. There are two trucks parked behind the lady.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Woman reaching over groups of vegetables]

Photograph of a woman arranging vegetables at a farmers market. There are two cargo trucks parked behind the lady.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Man with baskets of fruit and cardboard signs]

Photograph of a man at a farmers market with buckets of fruit placed in front of him. Two cardboard signs are also shown in the photograph describing the fruit prices.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Melon in foreground and man with baskets of vegetables in background]

Photograph of a man at a farmers market with buckets of fruit placed in front of him. Two cardboard signs are also shown in the photograph describing the fruit prices.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Woman paying for bags of produce]

Photograph of a lady paying for produce at a farmers market with a plastic bag on her left hand. The employee is handing over a plastic bag to the lady with her right hand while reaching for the payment with her left hand. A variety of vegetables are shown stacked in the photograph and cardboard signs describing prices.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Women placing produce into plastic bags]

None
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Woman placing sign in baskets of vegetables]

Photograph of a lady placing a price sign on a variety of vegetables at a farmers market. There are two cargo trucks parked behind the lady.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Man sitting behind melons and baskets of fruit]

Photograph of a man at a farmers market with buckets of fruit placed in front of him. Two cardboard signs are also shown in the photograph describing the fruit prices.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Man sitting behind containers of fruit]

Photograph of a man at a farmers market with buckets of fruit placed in front of him. Two cardboard signs are also shown in the photograph describing the fruit prices.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library

[Man sitting behind containers of apples and oranges]

Photograph of a man at a farmers market with buckets of fruit placed in front of him. Two cardboard signs are also shown in the photograph describing the fruit prices.
Date: August 14, 2006
Creator: Castillo, José L.
Object Type: Photograph
System: The UNT Digital Library
NEUTRON ACTIVATION ANALYSIS APPLICATIONS AT THE SAVANNAH RIVER SITE USING AN ISOTOPIC NEUTRON SOURCE (open access)

NEUTRON ACTIVATION ANALYSIS APPLICATIONS AT THE SAVANNAH RIVER SITE USING AN ISOTOPIC NEUTRON SOURCE

NAA using {sup 252}Cf is used to address important areas of applied interest at SRS. Sensitivity needs for many of the applications are not severe; analyses are accomplished using a 21 mg {sup 252}Cf NAA facility. Because NAA allows analysis of bulk samples, it offers strong advantages for samples in difficult-to-digest matrices when its sensitivity is sufficient. Following radiochemical separation with stable carrier addition, chemical yields for a number methods are determined by neutron activation of the stable carrier. In some of the cases where no suitable stable carriers exist, the source has been used to generate radioactive tracers to yield separations.
Date: August 14, 2006
Creator: Diprete, D; C Diprete, C & Raymond Sigg, R
Object Type: Article
System: The UNT Digital Library
Niobium Oxide-Metal Based Seals for High Temperature Applications (open access)

Niobium Oxide-Metal Based Seals for High Temperature Applications

The present final report describes technical progress made in regards to evaluating niobium oxide/alumina as a high temperature seal material. Fabrication and characterization of specimens comprising niobium oxide and alumina composites of various compositions was performed. The goal was to identify regions where a glass formed. There were no experimental conditions where a glassy phase was unequivocally identified. However, the results led to the formation of an interesting class of fibrous composites which may have applications where high compliance and high toughness are needed. It is clear that vapor phase sintering is an active mass transport mechanism in Nb{sub 2}O{sub 5}-Al{sub 2}O{sub 3} composites (Figure 1), and it may be possible to design porous materials by utilizing vapor phase sintering. The compositions evaluated in the present work are 52, 60, 73, 82 and 95 mol. % Nb{sub 2}O{sub 5} with the remainder Al{sub 2}O{sub 3}. These were chosen so that some eutectic composition was present during cooling, in an attempt to encourage glass formation. However, the presence of large, elongated crystals, both in the slow cool and the quench experiments indicates that the driving force for crystallization is very high. Several joints were formed between high purity alumina with two …
Date: August 14, 2006
Creator: Reimanis, Ivar
Object Type: Report
System: The UNT Digital Library
The Radiation Dose Measurement System for the BaBar Electromagnetic Calorimeter (open access)

The Radiation Dose Measurement System for the BaBar Electromagnetic Calorimeter

An array of 116 p-channel radiation sensitive MOSFET transistors (RadFETs) has been operational for the past 6 years at the BaBar experiment at the PEP-II asymmetric B-Factory at the Stanford Linear Accelerator Center (SLAC). This system maps the integrated dose absorbed by different regions of the Electromagnetic Calorimeter (EMC) during the running of the experiment. We report on the design and implementation of the system and finally, the performance of the monitoring system during the last 6 years of BaBar data-taking.
Date: August 14, 2006
Creator: Khan, A.; U., /Brunel; Meyer, W.T.; U., /Iowa State; Stelzer, J.; /Stanford U., Phys. Dept. et al.
Object Type: Article
System: The UNT Digital Library
Grid Application for the BaBar Experiment (open access)

Grid Application for the BaBar Experiment

This paper discusses the use of e-Science Grid in providing computational resources for modern international High Energy Physics (HEP) experiments. We investigate the suitability of the current generation of Grid software to provide the necessary resources to perform large-scale simulation of the experiment and analysis of data in the context of multinational collaboration.
Date: August 14, 2006
Creator: Khan, A.; U., /Brunel; Wilson, F. & /Rutherford
Object Type: Article
System: The UNT Digital Library
Time-resolved Temperature Measurements in SSPX (open access)

Time-resolved Temperature Measurements in SSPX

We seek to measure time-resolved electron temperatures in the SSPX plasma using soft X-rays from free-free Bremsstrahlung radiation. To increase sensitivity to changes in temperature over the range 100-300 eV, we use two photodiode detectors sensitive to different soft X-ray energies. The detectors, one with a Zr/C coating and the other with a Ti/Pd coating, view the plasma along a common line of sight tangential to the magnetic axis of the spheromak, where the electron temperature is a maximum. The comparison of the signals, over a similar volume of plasma, should be a stronger function of temperature than a single detector in the range of Te< 300 eV. The success of using photodiodes to detect changing temperatures along a chord will make the case for designing an array of the detectors, which could provide a time changing temperature profile over a larger portion of the plasma.
Date: August 14, 2006
Creator: Ludington, A. R.; Hill, D. N.; McLean, H. S.; Moller, J. & Wood, R. D.
Object Type: Report
System: The UNT Digital Library
Measurement of cross sections for alpha-induced reactions on 197Au and thick-target yields for the ((alpha),(gamma)) process on 64Zn and 63Cu (open access)

Measurement of cross sections for alpha-induced reactions on 197Au and thick-target yields for the ((alpha),(gamma)) process on 64Zn and 63Cu

We have measured the cross sections for the {sup 197}Au({alpha},{gamma}){sup 201}Tl and {sup 197}Au({alpha},2n){sup 199}Tl reactions in the 17.9- to 23.9-MeV energy range, and {sup 197}Au({alpha},n){sup 200}Tl reaction in the 13.4- to 23.9-MeV energy range using an activation technique. Thick-target yields for the {sup 64}Zn({alpha},{gamma}){sup 68}Ge (7- to 14-MeV) and {sup 63}Cu({alpha},{gamma}){sup 67}Ga (7-MeV) reactions were measured. For all measurements, natural elements were bombarded with He{sup +} beams from the 88'' Cyclotron at the Lawrence Berkeley National Laboratory (LBNL). Irradiated samples were counted using a g-spectrometry system at LBNL's Low Background Facility. Measured {sup 197}Au({alpha},{gamma}){sup 201}Tl cross-sections were compared with the NON-SMOKER theoretical values. The thick-target yields for the {sup 64}Zn({alpha},{gamma}){sup 68}Ge and {sup 63}Cu({alpha},{gamma}){sup 67}Ga reactions are also compared with the theoretical yield, calculated numerically using the energy dependent NON-SMOKER cross section data. In both cases, measured values are found to follow a trend of overlapping the predicted value near the alpha nucleus barrier height and fall below with a slowly widening difference between them in the sub barrier energy points.
Date: August 14, 2006
Creator: Basunia, M. S.; Shugart, H. A.; Smith, A. R. & Norman, E. B.
Object Type: Article
System: The UNT Digital Library
Air Convection Noise of Pencil-Beam Interfermeter for Long Trace Profiler (open access)

Air Convection Noise of Pencil-Beam Interfermeter for Long Trace Profiler

In this work, we investigate the effect of air convection on laser-beam pointing noise essential for the long trace profiler (LTP). We describe this pointing error with noise power density (NPD) frequency distributions. It is shown that the NPD spectra due to air convection have a very characteristic form. In the range of frequencies from {approx}0.05 Hz to {approx}0.5 Hz, the spectra can be modeled with an inverse-power-law function. Depending on the intensity of air convection that is controlled with a resistive heater of 100 to 150 mW along a one-meter-long optical path, the power index lies between 2 and 3 at an overall rms noise of {approx}0.5 to 1 microradian. The efficiency of suppression of the convection noise by blowing air across the beam optical path is also discussed. Air-blowing leads to a white-noise-like spectrum. Air blowing was applied to the reference channel of an LTP allowing demonstration of the contribution of air convection noise to the LTP reference beam. The ability to change (with the blowing technique presented) the spectral characteristics of the beam pointing noise due to air convection allows one to investigate the contribution of the convection effect, and thus make corrections to the power spectral …
Date: August 14, 2006
Creator: Yashchuk, V. V.; Irick, S. C.; MacDowell, A. A.; McKinney, W. R. & Takacs, P. Z.
Object Type: Article
System: The UNT Digital Library
MOSSFRAC: An anisotropic 3D fracture model (open access)

MOSSFRAC: An anisotropic 3D fracture model

Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by …
Date: August 14, 2006
Creator: Moss, W C & Levatin, J L
Object Type: Report
System: The UNT Digital Library