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Saturation of CVD Diamond Detectors
A 5 x 0.25 mm Chemical Vapor Deposited (CVD) diamond detector, with a voltage bias of + 250V, was excited by a 400 nm laser (3.1 eV photons) in order to study the saturation of the wafer and its surrounding electronics. In a first experiment, the laser beam energy was increased from a few tens of a pJ to about 100 µJ, and the signal from the diamond was recorded until full saturation of the detection system was achieved. Clear saturation of the detection system was observed at about 40 V, which corresponds with the expected saturation at 10% of the applied bias (250V). The results indicate that the interaction mechanism of the 3.1 eV photons in the diamond (Ebandgap = 5.45 eV) is not a multi-photon process but is linked to the impurities and defects of the crystal. In a second experiment, the detector was irradiated by a saturating first laser pulse and then by a delayed laser pulse of equal or smaller amplitude with delays of 5, 10, and 20 ns. The results suggest that the diamond and associated electronics recover within 10 to 20 ns after a strong saturating pulse.
Date:
January 1, 2005
Creator:
Dauffy, Lucile S.; Lerche, Richard A.; Schmid, Greg J.; Koch, Jeffrey A. & Silbernagel, Christopher
Object Type:
Article
System:
The UNT Digital Library
Quantum squeezed light for probing mitochondrial membranes and study of neuroprotectants.
We report a new nanolaser technique for measuring characteristics of human mitochondria. Because mitochondria are so small, it has been difficult to study large populations using standard light microscope or flow cytometry techniques. We recently discovered a nano-optical transduction method for high-speed analysis of submicron organelles that is well suited to mitochondrial studies. This ultrasensitive detection technique uses nano-squeezing of light into photon modes imposed by the ultrasmall organelle dimensions in a semiconductor biocavity laser. In this paper, we use the method to study the lasing spectra of normal and diseased mitochondria. We find that the diseased mitochondria exhibit larger physical diameter and standard deviation. This morphological differences are also revealed in the lasing spectra. The diseased specimens have a larger spectral linewidth than the normal, and have more variability in their statistical distributions.
Date:
January 1, 2005
Creator:
Gourley, Paul Lee; Copeland, Robert Guild; McDonald, Anthony Eugene; Hendricks, Judy K. & Naviaux, Robert K. (University of California, San Diego, CA)
Object Type:
Report
System:
The UNT Digital Library
Sensitivity technologies for large scale simulation.
Sensitivity analysis is critically important to numerous analysis algorithms, including large scale optimization, uncertainty quantification,reduced order modeling, and error estimation. Our research focused on developing tools, algorithms and standard interfaces to facilitate the implementation of sensitivity type analysis into existing code and equally important, the work was focused on ways to increase the visibility of sensitivity analysis. We attempt to accomplish the first objective through the development of hybrid automatic differentiation tools, standard linear algebra interfaces for numerical algorithms, time domain decomposition algorithms and two level Newton methods. We attempt to accomplish the second goal by presenting the results of several case studies in which direct sensitivities and adjoint methods have been effectively applied, in addition to an investigation of h-p adaptivity using adjoint based a posteriori error estimation. A mathematical overview is provided of direct sensitivities and adjoint methods for both steady state and transient simulations. Two case studies are presented to demonstrate the utility of these methods. A direct sensitivity method is implemented to solve a source inversion problem for steady state internal flows subject to convection diffusion. Real time performance is achieved using novel decomposition into offline and online calculations. Adjoint methods are used to reconstruct initial …
Date:
January 1, 2005
Creator:
Collis, Samuel Scott; Bartlett, Roscoe Ainsworth; Smith, Thomas Michael; Heinkenschloss, Matthias (Rice University, Houston, TX); Wilcox, Lucas C. (Brown University, Providence, RI); Hill, Judith C. (Carnegie Mellon University, Pittsburgh, PA) et al.
Object Type:
Report
System:
The UNT Digital Library
Habitat Evaluation Procedures (HEP) Report; Forrest Conservation Area, Technical Report 2003-2004.
The Habitat Evaluation Procedure (HEP) study was performed to determine baseline habitat units on the 4,232-acre Forrest Conservation Area managed by the Confederated Tribes of Warm Springs Reservation of Oregon (Tribe) in Grant County, Oregon. The habitat evaluation is required as part of the Memorandum of Agreement between the Confederated Tribes of the Warm Springs and Bonneville Power Administration. Representatives from the Washington Department of Fish and Wildlife and the Tribes conducted the field surveys for the HEP. The survey collected data for habitat variables contained in habitat suitability index (HIS) models for wildlife species; the key species were black-capped chickadee (Poecile atricapilla), mallard (Anas platyrhynchos), mink (Mustela vison), western meadowlark (Sturnella neglecta), mule deer (Odocoileus hemionus), California Quail (Callipepla californica), and yellow warbler (Dendroica petechia). Cover types surveyed were grassland, meadow grassland, conifer forest, riparian tree shrub, shrub steppe, juniper forest, and juniper steppe. Other cover types mapped, but not used in the models were open water, roads, gravel pits, corrals, and residential.
Date:
January 1, 2005
Creator:
Smith, Brent
Object Type:
Report
System:
The UNT Digital Library
Ironmaking Process Alternatives Screening Study Volume II: Appendix
None
Date:
January 10, 2005
Creator:
Lockwood Greene, . .
Object Type:
Report
System:
The UNT Digital Library
Unsymmetric ordering using a constrained Markowitz scheme
We present a family of ordering algorithms that can be used as a preprocessing step prior to performing sparse LU factorization. The ordering algorithms simultaneously achieve the objectives of selecting numerically good pivots and preserving the sparsity. We describe the algorithmic properties and challenges in their implementation. By mixing the two objectives we show that we can reduce the amount of fill-in in the factors and reduce the number of numerical problems during factorization. On a set of large unsymmetric real problems, we obtained the median reductions of 12% in the factorization time, of 13% in the size of the LU factors, of 20% in the number of operations performed during the factorization phase, and of 11% in the memory needed by the multifrontal solver MA41-UNS. A byproduct of this ordering strategy is an incomplete LU-factored matrix that can be used as a preconditioner in an iterative solver.
Date:
January 18, 2005
Creator:
Amestoy, Patrick R.; S., Xiaoye & Pralet, Stephane
Object Type:
Article
System:
The UNT Digital Library
Review of Systematic Investigations of the Rout/Rside ratio in HBT at RHIC
We review the significant difference in the ratio R{sub out}/R{sub side} between experiment and theory in heavy-ion collisions at RHIC. This ratio is expected to be strongly correlated with the pion emission duration. Hydrodynamic models typically calculate a value that approximately equal to 1.5 and moderately dependent on k{sub T} whereas the experiments report a value close to unity and independent of k{sub T}. We review those calculations in which systematic variations in the theoretical assumptions were reported. We find that the scenario of second order phase transition or cross-over has been given insufficient attention, and may play an important role in resolving this discrepancy.
Date:
January 6, 2005
Creator:
Soltz, R. A.
Object Type:
Article
System:
The UNT Digital Library
Averaging of Stochastic Equations for Flow and Transport in PorousMedia
It is well known that at present exact averaging of theequations of flow and transport in random porous media have been realizedfor only a small number of special fields. Moreover, the approximateaveraging methods are not yet fully understood. For example, theconvergence behavior and the accuracy of truncated perturbation seriesare not well known; and in addition, the calculation of the high-orderperturbations is very complicated. These problems for a long time havestimulated attempts to find the answer for the question: Are there inexistence some exact general and sufficiently universal forms of averagedequations? If the answer is positive, there arises the problem of theconstruction of these equations and analyzing them. There are manypublications on different applications of this problem to various fields,including: Hydrodynamics, flow and transport in porous media, theory ofelasticity, acoustic and electromagnetic waves in random fields, etc.Here, we present a method of finding some general form of exactlyaveraged equations for flow and transport in random fields by using (1)some general properties of the Green s functions for appropriatestochastic problems, and (2) some basic information about the randomfields of the conductivity, porosity and flow velocity. We presentgeneral forms of exactly averaged non-local equations for the followingcases: (1) steady-state flow with sources in …
Date:
January 7, 2005
Creator:
Shvidler, Mark & Karasaki, Kenzi
Object Type:
Article
System:
The UNT Digital Library
CH-TRU Waste Content Codes (CH-TRUCON)
The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container. Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 …
Date:
January 15, 2005
Creator:
Westinghouse TRU Solutions LLC
Object Type:
Report
System:
The UNT Digital Library
Nanofluidic devices for rapid detection of virus particles.
Technologies that could quickly detect and identify virus particles would play a critical role in fighting bioterrorism and help to contain the rapid spread of disease. Of special interest is the ability to detect the presence and movement of virions without chemically modifying them by attaching molecular probes. This would be useful for rapid detection of pathogens in food or water supplies without the use of expensive chemical reagents. Such detection requires new devices to quickly screen for the presence of tiny pathogens. To develop such a device, we fabricated nanochannels to transport virus particles through ultrashort laser cavities and measured the lasing output as a sensor for virions. To understand this transduction mechanism, we also investigated light scattering from virions, both to determine the magnitude of the scattered signal and to use it to investigate the motion of virions.
Date:
January 1, 2005
Creator:
Gourley, Paul Lee; McDonald, Anthony Eugene & Hendricks, Judy K.
Object Type:
Report
System:
The UNT Digital Library
A user's guide to radiation transport in ALEGRA-HEDP : version 4.6.
This manual describes the input syntax to the ALEGRA radiation transport package. All input and output variables are defined, as well as all algorithmic controls. This manual describes the radiation input syntax for ALEGRA-HEDP. The ALEGRA manual[2] describes how to run the code and general input syntax. The ALEGRA-HEDP manual[13] describes the input for other physics used in high energy density physics simulations, as well as the opacity models used by this radiation package. An emission model, which is the lowest order radiation transport approximation, is also described in the ALEGRA-HEDP manual. This document is meant to be used with these other manuals.
Date:
January 1, 2005
Creator:
Mehlhorn, Thomas Alan & Brunner, Thomas A.
Object Type:
Report
System:
The UNT Digital Library
LDRD final report : on the development of hybrid level-set/particle methods for modeling surface evolution during feature-scale etching and deposition processes.
Two methods for creating a hybrid level-set (LS)/particle method for modeling surface evolution during feature-scale etching and deposition processes are developed and tested. The first method supplements the LS method by introducing Lagrangian marker points in regions of high curvature. Once both the particle set and the LS function are advanced in time, minimization of certain objective functions adjusts the LS function so that its zero contour is in closer alignment with the particle locations. It was found that the objective-minimization problem was unexpectedly difficult to solve, and even when a solution could be found, the acquisition of it proved more costly than simply expanding the basis set of the LS function. The second method explored is a novel explicit marker-particle method that we have named the grid point particle (GPP) approach. Although not a LS method, the GPP approach has strong procedural similarities to certain aspects of the LS approach. A key aspect of the method is a surface rediscretization procedure--applied at each time step and based on a global background mesh--that maintains a representation of the surface while naturally adding and subtracting surface discretization points as the surface evolves in time. This method was coded in 2-D, and …
Date:
January 1, 2005
Creator:
McBride, Cory L. (Elemental Technologies, American Fork, UT); Schmidt, Rodney Cannon & Musson, Lawrence Cale
Object Type:
Report
System:
The UNT Digital Library
Si-based RF MEMS components.
Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.
Date:
January 1, 2005
Creator:
Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D. & Dyck, Christopher William
Object Type:
Report
System:
The UNT Digital Library
Development of UV-LED Phosphor Coatings for High Efficiency Solid State Lighting
The University of Georgia, in collaboration with GE Global Research, is investigating the relevant quenching mechanism of phosphor coatings used in white light devices based on UV LEDs in a focused eighteen month program. The final goal is the design of high-efficacy white UV-LEDs through improved and optimized phosphor coatings. At the end of the first year, we have reached a fundamental understanding of quenching processes in UV-LED phosphors and have observed severe quenching in standard devices under extreme operating conditions. Relationships are being established that describe the performance of the phosphor as a function of photon flux, temperature, and phosphor composition. These relationships will provide a road map for the design of efficient white light LEDs during the final six months of the project.
Date:
January 1, 2005
Creator:
Happek, U.
Object Type:
Report
System:
The UNT Digital Library
Performance evaluation of the SX-6 vector architecture forscientific computations
The growing gap between sustained and peak performance for scientific applications is a well-known problem in high performance computing. The recent development of parallel vector systems offers the potential to reduce this gap for many computational science codes and deliver a substantial increase in computing capabilities. This paper examines the intranode performance of the NEC SX-6 vector processor, and compares it against the cache-based IBMPower3 and Power4 superscalar architectures, across a number of key scientific computing areas. First, we present the performance of a microbenchmark suite that examines many low-level machine characteristics. Next, we study the behavior of the NAS Parallel Benchmarks. Finally, we evaluate the performance of several scientific computing codes. Overall results demonstrate that the SX-6 achieves high performance on a large fraction of our application suite and often significantly outperforms the cache-based architectures. However, certain classes of applications are not easily amenable to vectorization and would require extensive algorithm and implementation reengineering to utilize the SX-6 effectively.
Date:
January 1, 2005
Creator:
Oliker, Leonid; Canning, Andrew; Carter, Jonathan Carter; Shalf,John; Skinner, David; Ethier, Stephane et al.
Object Type:
Article
System:
The UNT Digital Library
Millimeter Wave Cloud Radar (MMCR) Handbook
The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.
Date:
January 30, 2005
Creator:
Widener, KB & Johnson, K
Object Type:
Report
System:
The UNT Digital Library
Sandia National Laboratories corporate mentor program : program review, May 2004.
The Sandia National Laboratories Corporate Mentor Program provides a mechanism for the development and retention of Sandia's people and knowledge. The relationships formed among staff members at different stages in their careers offer benefits to all. These relationships can provide experienced employees with new ideas and insight and give less experienced employees knowledge of Sandia's culture, strategies, and programmatic direction. The program volunteer coordinators are dedicated to the satisfaction of the participants, who come from every area of Sandia. Since its inception in 1995, the program has sustained steady growth and excellent customer satisfaction. This report summarizes the accomplishments, activities, enhancements, and evaluation data for the Corporate Mentor Program for the 2003/2004 program year ending May 1, 2004.
Date:
January 1, 2005
Creator:
Tibbetts, Tiffany; Tarro, Talitha; Dudeck, William; Bristol, Colette & Stephens, Jim
Object Type:
Report
System:
The UNT Digital Library
Spin-on-glass coatings for the generation of super-polishedsubstrates for extreme ultraviolet optics
Substrates intended for use as extreme ultraviolet (EUV) optics have extremely stringent requirements in terms of finish. These requirements can dramatically increase the cost and fabrication time, especially when non-conventional shapes, such as toroids, are required. Here we present a spin-on-glass resist process capable of generating super-polished parts from inexpensive substrates. The method has been used to render diamond-turned substrates compatible for use as EUV optics. Toroidal diamond-turned optics with starting rms roughness in the 3.3 to 3.7 nm range have been smoothed to the 0.4 to 0.6 nm range. EUV reflectometry characterization of these optics has demonstrated reflectivities of approximately 63%.
Date:
January 1, 2005
Creator:
Salmassi, Farhad; Naulleau, Patrick P. & Gullikson, Eric M.
Object Type:
Article
System:
The UNT Digital Library
Automated visual direction : LDRD 38623 final report.
Mobile manipulator systems used by emergency response operators consist of an articulated robot arm, a remotely driven base, a collection of cameras, and a remote communications link. Typically the system is completely teleoperated, with the operator using live video feedback to monitor and assess the environment, plan task activities, and to conduct the operations via remote control input devices. The capabilities of these systems are limited, and operators rarely attempt sophisticated operations such as retrieving and utilizing tools, deploying sensors, or building up world models. This project has focused on methods to utilize this video information to enable monitored autonomous behaviors for the mobile manipulator system, with the goal of improving the overall effectiveness of the human/robot system. Work includes visual servoing, visual targeting, utilization of embedded video in 3-D models, and improved methods of camera utilization and calibration.
Date:
January 1, 2005
Creator:
Anderson, Robert J.
Object Type:
Report
System:
The UNT Digital Library
Assessment of disinfectants in explosive destruction system for biological agent destruction : LDRD final report FY04.
Treatment systems that can neutralize biological agents are needed to mitigate risks from novel and legacy biohazards. Tests with Bacillus thuringiensis and Bacillus steurothemophilus spores were performed in a 190-liter, 1-112 lb TNT equivalent rated Explosive Destruction System (EDS) system to evaluate its capability to treat and destroy biological agents. Five tests were conducted using three different agents to kill the spores. The EDS was operated in steam autoclave, gas fumigation and liquid decontamination modes. The first three tests used EDS as an autoclave, which uses pressurized steam to kill the spores. Autoclaving was performed at 130-140 deg C for up to 2-hours. Tests with chlorine dioxide at 750 ppm concentration for 1 hour and 10% (vol) aqueous chlorine bleach solution for 1 hour were also performed. All tests resulted in complete neutralization of the bacterial spores based on no bacterial growth in post-treatment incubations. Explosively opening a glass container to expose the bacterial spores for treatment with steam was demonstrated and could easily be done for chlorine dioxide gas or liquid bleach.
Date:
January 1, 2005
Creator:
Simmons, Blake Alexander; Didlake, John E. Jr.; Bradshaw, Robert W.; Crooker, Paul J. & Buffleben, George M.
Object Type:
Report
System:
The UNT Digital Library
Infrared Lorentz Violation and Slowly InstantaneousElectricity
None
Date:
January 19, 2005
Creator:
Dvali, Gia; Papucci, Michele & Schwartz, Matthew D.
Object Type:
Article
System:
The UNT Digital Library
Modeling local chemistry in the presence of collective phenomena.
Confinement within the nanoscale pores of a zeolite strongly modifies the behavior of small molecules. Typical of many such interesting and important problems, realistic modeling of this phenomena requires simultaneously capturing the detailed behavior of chemical bonds and the possibility of collective dynamics occurring in a complex unit cell (672 atoms in the case of Zeolite-4A). Classical simulations alone cannot reliably model the breaking and formation of chemical bonds, while quantum methods alone are incapable of treating the extended length and time scales characteristic of complex dynamics. We have developed a robust and efficient model in which a small region treated with the Kohn-Sham density functional theory is embedded within a larger system represented with classical potentials. This model has been applied in concert with first-principles electronic structure calculations and classical molecular dynamics and Monte Carlo simulations to study the behavior of water, ammonia, the hydroxide ion, and the ammonium ion in Zeolite-4a. Understanding this behavior is important to the predictive modeling of the aging of Zeolite-based desiccants. In particular, we have studied the absorption of these molecules, interactions between water and the ammonium ion, and reactions between the hydroxide ion and the zeolite cage. We have shown that interactions …
Date:
January 1, 2005
Creator:
Chandross, Michael Evan & Modine, Normand Arthur
Object Type:
Report
System:
The UNT Digital Library
Radiative and Dynamical Feedbacks Over the Equatorial Cold-Tongue: Results from Seven Atmospheric GCMs
The equatorial Pacific is a region with strong negative feedbacks. Yet coupled GCMs have exhibited a propensity to develop a significant SST bias in that region, suggesting an unrealistic sensitivity in the coupled models to small energy flux errors that inevitably occur in the individual model components. Could this 'hypersensitivity' exhibited in a coupled model be due to an underestimate of the strength of the negative feedbacks in this region? With this suspicion, the feedbacks in the equatorial Pacific in seven atmospheric GCMs (AGCMs) have been quantified using the interannual variations in that region and compared with the corresponding calculations from the observations. The seven AGCMs are: the NCAR CAM1, the NCAR CAM2,the NCAR CAM3, the NASA/NSIPP Atmospheric Model, the Hadley Center Model, the GFDL AM2p10, and the GFDL AM2p12. All the corresponding coupled runs of these seven AGCMs have an excessive cold-tongue in the equatorial Pacific. The net atmospheric feedback over the equatorial Pacific in the two GFDL models is found to be comparable to the observed value. All other models are found to have a weaker negative net feedback from the atmosphere--a weaker regulating effect on the underlying SST than the real atmosphere. A weaker negative feedback from …
Date:
January 4, 2005
Creator:
Sun, D.; Zhang, T.; Covey, C.; Klein, S.; Collins, W.; Kiehl, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Understanding Ultra-Scale Application CommunicationRequirements
As thermal constraints reduce the pace of CPU performance improvements, the cost and scalability of future HPC architectures will be increasingly dominated by the interconnect. In this work we perform an in-depth study of the communication requirements across a broad spectrum of important scientific applications, whose computational methods include: finite-difference, lattice-boltzmann, particle in cell, sparse linear algebra, particle mesh ewald, and FFT-based solvers. We use the IPM (integrated Performance Monitoring) profiling framework to collect detailed statistics on communication topology and message volume with minimal impact to code performance. By characterizing the parallelism and communication requirements of such a diverse set of applications, we hope to guide architectural choices for the design and implementation of interconnects for future HPC systems.
Date:
January 1, 2005
Creator:
Shoaib, Kamil; Shalf, John; Oliker, Leonid & Skinner, David
Object Type:
Article
System:
The UNT Digital Library