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[Publicity Articles for Brilliant Magazine] (open access)

[Publicity Articles for Brilliant Magazine]

Press kit containing articles about the launching of Brilliant Magazine by Brilliance Media in Austin, Texas.
Date: 2003-03/2004-01
Creator: unknown
System: The UNT Digital Library
Delamination Failure Investigation for Out-Of-Plane Loading in Laminates (open access)

Delamination Failure Investigation for Out-Of-Plane Loading in Laminates

In contrast to failure approaches at the lamina level or the micromechanics level the present work concerns failure characterization at the laminate level. Specifically, attention is given to the ultimate failure characterization for quasi-isotropic laminates. This is in further contrast to the commonly used approaches for initial damage or progressive damage. It is shown that the analytical failure forms decompose into two modes, one for out of plane, delamination type failure and one for in plane, fiber controlled type failure. The work here is mainly given over to the delamination mode of failure. Experimental results are presented for laminates in this mode of failure. These results are then integrated with the analytical forms to give a simple criterion for delamination failure.
Date: March 26, 2003
Creator: Christensen, R M & DeTeresa, S J
System: The UNT Digital Library
A Systematic Approach for the Evaluation of Technology Opportunities to Enhance the Proliferation Resistance of Civilian Nuclear Energy Systems (open access)

A Systematic Approach for the Evaluation of Technology Opportunities to Enhance the Proliferation Resistance of Civilian Nuclear Energy Systems

Enhancing the proliferation resistance of nuclear energy systems and fuel cycles is an ambitious undertaking. Current systems, dominated by the light water reactor fuel cycle are quite proliferation resistant. However, continued accumulations of plutonium in spent fuel and accumulations of separated plutonium resulting from reprocessing are eroding the proliferation resistance of today's nuclear energy systems. Alternatives to address these issues invariably involve making trade-offs among different proliferation risks and advantages. For example, thorium cycles reduce the quantity and quality of plutonium in spent fuel, but do so at the expense of increased fresh fuel enrichment and/or production of separable U233. Evaluation of these tradeoffs is difficult, as there are serious and significant differences of opinion regarding the relative merits and significance of the various risks of and barriers to proliferation from commercial nuclear power fuel cycles.
Date: March 10, 2003
Creator: Hassberger, J
System: The UNT Digital Library
Passive Seismic Monitoring for Rockfall at Yucca Mountain: Concept Tests (open access)

Passive Seismic Monitoring for Rockfall at Yucca Mountain: Concept Tests

For the purpose of proof-testing a system intended to remotely monitor rockfall inside a potential radioactive waste repository at Yucca Mountain, a system of seismic sub-arrays will be deployed and tested on the surface of the mountain. The goal is to identify and locate rockfall events remotely using automated data collecting and processing techniques. We install seismometers on the ground surface, generate seismic energy to simulate rockfall in underground space beneath the array, and interpret the surface response to discriminate and locate the event. Data will be analyzed using matched-field processing, a generalized beam forming method for localizing discrete signals. Software is being developed to facilitate the processing. To date, a three-component sub-array has been installed and successfully tested.
Date: March 3, 2003
Creator: Cheng, J.; Twilley, K.; Murvosh, H.; Tu, Y.; Luke, B.; Yfantis, A. et al.
System: The UNT Digital Library
Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays (open access)

Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays

With a sample of approximately 89 million B{bar B} pairs collected with the BABAR detector, they measure branching fractions, determine the degree of longitudinal polarization, and search for direct CP violation in the decays B{sup 0} {yields} {phi}K*{sup 0} and B{sup +} {yields} {phi}K*{sup +}. They perform a search for other charmless vector-vector B decays involving {rho} and K*(892) resonances and observe the decays B{sup +} {yields} {rho}{sup 0} K*{sup +} and B{sup +} {yields} {rho}{sup 0}{rho}{sup +}. The branching fractions are measured to be {Beta}({phi}K*{sup 0}) = (11.1{sub -1.2}{sup +1.3} {+-} 1.1) x 10{sup -6}, {Beta}({phi}K*{sup +}) = (12.1{sub -1.9}{sup +2.1} {+-} 1.5) x 10{sup -6}, {Beta}({rho}{sup 0} K*{sup +}) = (7.7{sub -2.0}{sup +2.1} {+-} 1.4) x 10{sup -6}, and {Beta}({rho}{sup 0}{rho}{sup +}) = (9.9{sub -2.5}{sup +2.6} {+-} 2.5) x 10{sup -6}. The longitudinal polarization fractions are measured to be {Lambda}{sub L}/{Lambda}({phi}K*{sup 0}) = 0.65 {+-} 0.07 {+-} 0.04 and {Lambda}{sub L}/{Lambda}({phi}K*{sup +}) = 0.46 {+-} 0.12 {+-} 0.05. They measure the charge asymmetries: {Alpha}{sub CP}({phi}K*{sup 0}) = +0.04 {+-} 0.12 {+-} 0.02 and {Alpha}{sub CP}({phi}K*{sup +}) = +0.16 {+-} 0.17 {+-} 0.04.
Date: March 11, 2003
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y. et al.
System: The UNT Digital Library
Design and Performance of Capping Layers for EUV Multilayer Mirrors (open access)

Design and Performance of Capping Layers for EUV Multilayer Mirrors

The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of uttermost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multilayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.
Date: March 10, 2003
Creator: Bajt, S.; Chapman, H. N.; Nuygen, N.; Alameda, J.; Robinson, J. C.; Malinowski, M. et al.
System: The UNT Digital Library
Associated Higgs Boson Production With Heavy Quarks. (open access)

Associated Higgs Boson Production With Heavy Quarks.

The production of a Higgs boson in association with a pair of e quarks will play a very important role at both hadron and lepton colliders. We review the status of theoretical predictions and their relevance to Higgs boson studies, with particular emphasis on the recently calculated NLO QCD corrections to the inclusive cross section for p{bar p}, pp {yields} t{bar t}h. We conclude by briefly discussing the case of exclusive b{bar b}h production and the potential of this process in revealing signals of new physics beyond the Standard Model.
Date: March 15, 2003
Creator: Dawson, S.; Orr, L. H.; Reina, L. & Wackeroth, D.
System: The UNT Digital Library
Adaptive Optics Applications in Vision Science (open access)

Adaptive Optics Applications in Vision Science

Adaptive optics can be used to correct the aberrations in the human eye caused by imperfections in the cornea and the lens and thereby, improve image quality both looking into and out of the eye. Under the auspices of the NSF Center for Adaptive Optics and the DOE Biomedical Engineering Program, Lawrence Livermore National Laboratory has joined together with leading vision science researchers around the country to develop and test new ophthalmic imaging systems using novel wavefront corrector technologies. Results of preliminary comparative evaluations of these technologies in initial system tests show promise for future clinical utility.
Date: March 17, 2003
Creator: Olivier, S. S.
System: The UNT Digital Library
Materials Science under Extreme Conditions of Pressure and Strain Rate (open access)

Materials Science under Extreme Conditions of Pressure and Strain Rate

Solid state dynamics experiments at very high pressures (P >> 10 GPa) and strain rates ({var_epsilon} >> 10{sup 5} s{sup -1}) have been demonstrated on high energy laser facilities, albeit over brief intervals of time and small spatial scales. We have developed two methods for driving samples to high pressures (10-100 GPa) at high strain rate (10{sup 6}-10{sup 8} s{sup -1}) in the solid state. One method uses a shockless compression technique, and the other uses multiple staged shocks. These drives are calibrated with VISAR measurements of the resulting compression wave. Deformation mechanisms are inferred under these conditions by characterizing recovered samples. Material strength at high pressures and strain rates is deduced by measuring the reduced growth of material perturbations at a hydrodynamically unstable interface. Microscopic lattice response is determined by time-resolved Bragg diffraction and x-ray absorption spectroscopy (EXAFS). Large-scale simulations, both at the continuum level using constitutive models and at the lattice level using molecular dynamics simulation, are used to interpret these integral experiments. We will review our progress in this new area of laser-based materials science research, then present a vision for carrying these solid-state experiments to much higher pressures, P > 1000 GPa, on the National Ignition …
Date: March 27, 2003
Creator: Remington, B. A.; Bazan, G.; Bringa, E.; Caturla, M.; Edwards, M. J.; Glendinning, S. G. et al.
System: The UNT Digital Library
The Effects of Radiation Induced Carbon Contamination on the Performance of an EUV Lithographic Optic (open access)

The Effects of Radiation Induced Carbon Contamination on the Performance of an EUV Lithographic Optic

Carbon deposition in EUVL is known to occur when optical surfaces in a hydrocarbon environment are exposed to EUV light. Carbon contamination on EUV optical elements affects both the absorption and phase of the reflected light. Because the carbon deposition alters the phase structure of the reflected EUV light it effectively alters the figure of these optics and, thus, the aberrations as well. Absorption by deposited carbon not only reduces throughput but also leads to apodisation of the pupil, which in turn affects imaging performance.
Date: March 9, 2003
Creator: Barty, A. & Goldberg, K.
System: The UNT Digital Library
Adaptive Optics at Lawrence Livermore National Laboratory (open access)

Adaptive Optics at Lawrence Livermore National Laboratory

Adaptive optics enables high resolution imaging through the atmospheric by correcting for the turbulent air's aberrations to the light waves passing through it. The Lawrence Livermore National Laboratory for a number of years has been at the forefront of applying adaptive optics technology to astronomy on the world's largest astronomical telescopes, in particular at the Keck 10-meter telescope on Mauna Kea, Hawaii. The technology includes the development of high-speed electrically driven deformable mirrors, high-speed low-noise CCD sensors, and real-time wavefront reconstruction and control hardware. Adaptive optics finds applications in many other areas where light beams pass through aberrating media and must be corrected to maintain diffraction-limited performance. We describe systems and results in astronomy, medicine (vision science), and horizontal path imaging, all active programs in our group.
Date: March 10, 2003
Creator: Gavel, D T
System: The UNT Digital Library
Poroelastic Analysis of Thomsen Parameters in Finely Layed VTI Media (open access)

Poroelastic Analysis of Thomsen Parameters in Finely Layed VTI Media

Thomsen's anisotropy parameters for weak elastic and poroelastic anisotropy are now commonly used in exploration, and can be conveniently expressed in terms of the layer averages of Backus. Although there are five effective shear moduli for any layered VTI medium, only one effective shear modulus for the layered system contains all the dependence of pore fluids on the elastic or poroelastic constants that can be observed in vertically polarized shear waves in VTI media. The effects of the pore fluids on this effective shear modulus can be substantial when the medium behaves in an undrained fashion, as might be expected at higher frequencies such a sonic and ultrasonic for well-logging or laboratory experiments, or at seismic frequencies for lower permeability regions of reservoirs.
Date: March 17, 2003
Creator: Berger, E. L.
System: The UNT Digital Library
TECHNIQUES FOR NNLO HIGGS PRODUCTION IN THE STANDARD MODEL AND MSSM. (open access)

TECHNIQUES FOR NNLO HIGGS PRODUCTION IN THE STANDARD MODEL AND MSSM.

New techniques developed in connection with the NNLO corrections to the Higgs production rate at hadron colliders and some recent applications are reviewed.
Date: March 22, 2003
Creator: HARLANDER,R. V. KILGORE,W. B.
System: The UNT Digital Library
Understanding Particle Defect Transport in an Ultra-Clean Sputter Coating Process (open access)

Understanding Particle Defect Transport in an Ultra-Clean Sputter Coating Process

Low-defect mask blanks remain a key technical challenge to Extreme Ultraviolet Lithography (EUVL). The mask blank is ion-beam sputter-coated with an 81-layer Mo/Si multilayer stack for high reflectance at {lambda} = 13.4nm. The current mask coating process can achieve a median added defect level of 0.05 defects/cm{sup 2} (12 added defects 90nm or larger on a 200mm Si-wafer test substrate), but this must be reduced by about a factor of 10 to meet mask cost requirements for EUVL. To further reduce the particle defect level, we have studied pathways for particle transport, using test particles and particles native to the coating process, and combined the results into a computational model of particle transport in an ion-beam sputter system. At process pressure, gas drag is negligible for particles above 100nm, so particles travel ballistically until they hit a surface. Bounce from chamber walls allows particles to reach all surfaces in the chamber if they have initial velocities above {approx}100m/s. The ion beam has sufficient momentum to entrain slower particles and accelerate them toward the sputter target, where some can bounce to the substrate. The model shows preliminary agreement with experimental defect distributions on witness wafers at various positions within the coating …
Date: March 24, 2003
Creator: Walton, C.; Kearney, P.; Folta, J.; Sweeney, D. & Mirkarimi, P.
System: The UNT Digital Library
SUSY SIGNATURES IN ATLAS AT LHC. (open access)

SUSY SIGNATURES IN ATLAS AT LHC.

This talk summarizes work by the ATLAS Collaboration at the CERN Large Hadron Collider on the search SUSY particles and Higgs bosons and on possible measurements of their properties.
Date: March 17, 2003
Creator: PAIGE,F. E.
System: The UNT Digital Library
Towards Perceptual Interface for Visualization Navigation of Large Data Sets Using Gesture Recognition with Bezier Curves and Registered 3-D Data (open access)

Towards Perceptual Interface for Visualization Navigation of Large Data Sets Using Gesture Recognition with Bezier Curves and Registered 3-D Data

This paper presents a gesture recognition system for visualization navigation. Scientists are interested in developing interactive settings for exploring large data sets in an intuitive environment. The input consists of registered 3-D data. A geometric method using Bezier curves is used for the trajectory analysis and classification of gestures. The hand gesture speed is incorporated into the algorithm to enable correct recognition from trajectories with variations in hand speed. The method is robust and reliable: correct hand identification rate is 99.9% (from 1641 frames), modes of hand movements are correct 95.6% of the time, recognition rate (given the right mode) is 97.9%. An application to gesture-controlled visualization of 3D bioinformatics data is also presented.
Date: March 20, 2003
Creator: Shin, M C; Tsap, L V & Goldgof, D B
System: The UNT Digital Library
UAV Cooperation Architectures for Persistent Sensing (open access)

UAV Cooperation Architectures for Persistent Sensing

With the number of small, inexpensive Unmanned Air Vehicles (UAVs) increasing, it is feasible to build multi-UAV sensing networks. In particular, by using UAVs in conjunction with unattended ground sensors, a degree of persistent sensing can be achieved. With proper UAV cooperation algorithms, sensing is maintained even though exceptional events, e.g., the loss of a UAV, have occurred. In this paper a cooperation technique that allows multiple UAVs to perform coordinated, persistent sensing with unattended ground sensors over a wide area is described. The technique automatically adapts the UAV paths so that on the average, the amount of time that any sensor has to wait for a UAV revisit is minimized. We also describe the Simulation, Tactical Operations and Mission Planning (STOMP) software architecture. This architecture is designed to help simulate and operate distributed sensor networks where multiple UAVs are used to collect data.
Date: March 20, 2003
Creator: Roberts, R. S.; Kent, C. A. & Jones, E. D.
System: The UNT Digital Library
A PULSED MODULATOR POWER SUPPLY FOR THE G-2 MUON STORAGE RING INJECTION KICKER. (open access)

A PULSED MODULATOR POWER SUPPLY FOR THE G-2 MUON STORAGE RING INJECTION KICKER.

This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the 8-2 storage ring that has been built at Brookhaven National Laboratory. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, a damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95kV. The damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. This paper discusses the modulator design, construction and operation.
Date: March 1, 2003
Creator: MI,J. LEE,Y. Y. MORSE,W. M. PAI,C. I. PAPPAS,G. C. SANDERS,Y. SEMERTIZIDIS,Y.,ET AL.
System: The UNT Digital Library
Building a Successful Machine Safeguarding Program (open access)

Building a Successful Machine Safeguarding Program

Safeguarding hazards associated with machines is a goal common to all health and safety professionals. Whether the individual is new to the safety field or has held associated responsibilities for a period of time, safeguarding personnel who work with or around machine tools and equipment should be considered an important aspect of the job. Although significant progress has been made in terms of safeguarding machines since the era prior to the organized safety movement, companies continue to be cited by the Occupational Safety and Health Administration (OSHA) and workers continue to be injured, even killed by machine tools and equipment. In the early 1900s, it was common practice to operate transmission machinery (gears, belts, pulleys, shafting, etc.) completely unguarded. At that time, the countersunk set screw used on shafting had not been invented and projecting set screws were involved in many horrific accidents. Manufacturers built machines with little regard for worker safety. Workers were killed or seriously injured before definitive actions were taken to improve safety in the workplace. Many states adopted legislation aimed at requiring machine guarding and improved injury reduction. The first patent for a machine safeguard was issued in 1868 for a mechanical interlock. Other patents followed. …
Date: March 6, 2003
Creator: McConnell, S
System: The UNT Digital Library
Nanotechnology Based Environmentally Robust Primers (open access)

Nanotechnology Based Environmentally Robust Primers

An initiator device structure consisting of an energetic metallic nano-laminate foil coated with a sol-gel derived energetic nano-composite has been demonstrated. The device structure consists of a precision sputter deposition synthesized nano-laminate energetic foil of non-toxic and non-hazardous metals along with a ceramic-based energetic sol-gel produced coating made up of non-toxic and non-hazardous components such as ferric oxide and aluminum metal. Both the nano-laminate and sol-gel technologies are versatile commercially viable processes that allow the ''engineering'' of properties such as mechanical sensitivity and energy output. The nano-laminate serves as the mechanically sensitive precision igniter and the energetic sol-gel functions as a low-cost, non-toxic, non-hazardous booster in the ignition train. In contrast to other energetic nanotechnologies these materials can now be safely manufactured at application required levels, are structurally robust, have reproducible and engineerable properties, and have excellent aging characteristics.
Date: March 18, 2003
Creator: Barbee, T. W., Jr.; Gash, A. E.; Satcher, J. H. Jr. & Simpson, R. L.
System: The UNT Digital Library
Impact Analysis of Spent Fuel Dry Casks Under Accidental Drop Scenarios. (open access)

Impact Analysis of Spent Fuel Dry Casks Under Accidental Drop Scenarios.

A series of analyses were performed to assess the structural response of spent nuclear fuel dry casks subjected to various handling and on-site transfer events. The results of these analyses are being used by the Nuclear Regulatory Commission (NRC) to perform a probabilistic risk assessment (PRA). Although the PRA study is being performed for a specific nuclear plant, the PRA study is also intended to provide a framework for a general methodology that could also be applied to other dry cask systems at other nuclear plants. The dry cask system consists of a transfer cask, used for handling and moving the multi-purpose canister (MPC) that contains the fuel, and a storage cask, used to store the MPC and fuel on a concrete pad at the site. This paper describes the analyses of the casks for two loading events. The first loading consists of dropping the transfer cask while it is lowered by a crane to a concrete floor at ground elevation. The second loading consists of dropping the storage cask while it is being transferred to the concrete storage pad outdoors. Three dimensional finite element models of the transfer cask and storage cask, containing the MPC and fuel, were utilized …
Date: March 17, 2003
Creator: Braverman, J. I.; Morante, R. J.; Xu, J.; Hofmayer, C. H. & Shaukat, S. K.
System: The UNT Digital Library
The Dynamic Movement of Plutonium in an Underground Nuclear Test with Implications for the Contamination of Groundwater (open access)

The Dynamic Movement of Plutonium in an Underground Nuclear Test with Implications for the Contamination of Groundwater

The recent discovery of the migration of plutonium in groundwater away from underground nuclear tests at the Nevada Test Site has spawned considerable interest in the mechanisms by which plutonium may be released to the environment by a nuclear test. A suite of solid debris samples was collected during drilling through an expended test cavity and the overlying collapse chimney. Uranium and plutonium were analyzed for isotope ratios and concentration using high precision magnetic sector inductively coupled mass spectrometry. The data unequivocally shows that plutonium may be dispersed throughout the cavity and chimney environment at the time of the detonation. The {sup 239}Pu/{sup 240}Pu ratios are also fractionated relative to initial plutonium isotope ratio for the test device. Fractionation is the result of the volatilization of uranium and production of {sup 239}Pu by the reaction {sup 238}U (n,{gamma}). We conclude that for the test under consideration plutonium was deposited outside of the confines of the cavity by dynamic processes in early-time and it is this plutonium that is most likely first transferred to the groundwater regime.
Date: March 25, 2003
Creator: Smith, D. K. & Williams, R. W.
System: The UNT Digital Library
ELECTRO-OPTICAL DETECTION OF CHARGED PARTICLE BEAMS. (open access)

ELECTRO-OPTICAL DETECTION OF CHARGED PARTICLE BEAMS.

We have made the first observation of a charged particle beam by means of its electro-optical effect on the propagation of laser light in a birefringent crystal at the Brookhaven National Laboratory Accelerator Test Facility. Polarized infrared light was coupled to a LiNbO{sub 3} crystal through a polarization maintaining fiber of 4 micron diameter. An electron beam in 10 ps bunches of 1 mm diameter was scanned across the crystal. The modulation of the laser light during passage of the electron beam was observed using a photodiode with 45 GHz bandwidth. The fastest rise time measured, 120 ps, was made in the single shot mode and was limited by the bandwidth of the oscilloscope and the associated electronics. Both polarization dependent and polarization independent effects were observed. This technology holds promise of greatly improved spatial and temporal resolution of charged particle beams.
Date: March 1, 2003
Creator: SEMERTZIDIS,Y. K. CASTILLO,V. LARSEN,R. C. LAZARUS,D. M. MAGURNO,B. SRINIVASAN-RAO,T. TSANG,T. USACK,V.,ET AL.
System: The UNT Digital Library
Solar Radiation Modeling and Measurements for Renewable Energy Applications: Data and Model Quality; Preprint (open access)

Solar Radiation Modeling and Measurements for Renewable Energy Applications: Data and Model Quality; Preprint

Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software and for outdoor pyranometer calibrations is outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data.
Date: March 1, 2003
Creator: Myers, D. R.
System: The UNT Digital Library