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1?10 kW Stationary Combined Heat and Power Systems Status and Technical Potential: Independent Review (open access)

1?10 kW Stationary Combined Heat and Power Systems Status and Technical Potential: Independent Review

This independent review examines the status and technical potential of 1-10 kW stationary combined heat and power fuel cell systems and analyzes the achievability of the DOE cost, efficiency, and durability targets for 2012, 2015, and 2020.
Date: November 1, 2010
Creator: Maru, H. C.; Singhal, S. C.; Stone, C. & Wheeler, D.
Object Type: Report
System: The UNT Digital Library
1-D Van der Waals Foams Heated by Ion Beam Energy Deposition (open access)

1-D Van der Waals Foams Heated by Ion Beam Energy Deposition

One dimensional simulations of various initial average density aluminum foams (modeled as slabs of solid metal separated by low density regions) heated by volumetric energy deposition are conducted with a Lagrangian hydrodynamics code using a van der Waals equation of state (EOS). The resulting behavior is studied to facilitate the design of future warm dense matter (WDM) experiments at LBNL. In the simulations the energy deposition ranges from 10 to 30 kJ/g and from 0.075 to 4.0 ns total pulse length, resulting in temperatures from approximately 1 to 4 eV. We study peak pressures and temperatures in the foams, expansion velocity, and the phase evolution. Five relevant time scales in the problem are identified. Additionally, we present a method for characterizing the level of inhomogeneity in a foam target as it is heated and the time it takes for a foam to homogenize.
Date: March 19, 2010
Creator: Zylstra, A; Barnard, J J & More, R M
Object Type: Article
System: The UNT Digital Library
2 x 2 Polyethylene Reflected and Moderated Highly Enriched Uranium System with Rhenium (open access)

2 x 2 Polyethylene Reflected and Moderated Highly Enriched Uranium System with Rhenium

The 2 × 2 array HEU-Re experiment was performed on the Planet universal critical assembly machine on November 4th, 2003 at the Los Alamos Critical Experiments Facility (LACEF) at Los Alamos National Laboratory (LANL). For this experiment, there were 10 ½ units, each full unit containing four HEU foils and two rhenium foils. The top unit contained only two HEU foils and two rhenium foils. A total of 42 HEU foils were used for this experiment. Rhenium is a desirable cladding material for space nuclear power applications. This experiment consisted of HEU foils interleaved with rhenium foils and is moderated and reflected by polyethylene plates. A unit consisted of a polyethylene plate, which has a recess for rhenium foils, and four HEU foils in a single layer in the top recess of each polyethylene plate. The Planet universal criticality assembly machine has been previously used in experiments containing HEU foils interspersed with SiO2 (HEU-MET-THERM-001), Al (HEU-MET-THERM-008), MgO (HEU-MET-THERM-009), Gd foils (HEU-MET-THERM-010), 2 × 2 × 26 Al (HEU-MET-THERM-012), Fe (HEU-MET-THERM-013 and HEU-MET-THERM-015), 2 × 2 × 23 SiO2 (HEU-MET-THERM-014), 2 × 2 × 11 hastalloy plates (HEU-MET-THERM-016), and concrete (HEU-MET-THERM-018). The 2 × 2 array of HEU-Re is considered acceptable …
Date: September 1, 2010
Creator: Ellis, A. Nichole; Hutchinson, Jesson; Bess, John D.; Polyakov, Dmitry N.; Glushkov, Evgeny S. & Glushkov, Alexey E.
Object Type: Report
System: The UNT Digital Library
3-D Mapping Technologies for High Level Waste Tanks (open access)

3-D Mapping Technologies for High Level Waste Tanks

This research investigated four techniques that could be applicable for mapping of solids remaining in radioactive waste tanks at the Savannah River Site: stereo vision, LIDAR, flash LIDAR, and Structure from Motion (SfM). Stereo vision is the least appropriate technique for the solids mapping application. Although the equipment cost is low and repackaging would be fairly simple, the algorithms to create a 3D image from stereo vision would require significant further development and may not even be applicable since stereo vision works by finding disparity in feature point locations from the images taken by the cameras. When minimal variation in visual texture exists for an area of interest, it becomes difficult for the software to detect correspondences for that object. SfM appears to be appropriate for solids mapping in waste tanks. However, equipment development would be required for positioning and movement of the camera in the tank space to enable capturing a sequence of images of the scene. Since SfM requires the identification of distinctive features and associates those features to their corresponding instantiations in the other image frames, mockup testing would be required to determine the applicability of SfM technology for mapping of waste in tanks. There may be …
Date: August 31, 2010
Creator: Marzolf, A. & Folsom, M.
Object Type: Article
System: The UNT Digital Library
A 3-dimensional theory of free electron lasers (open access)

A 3-dimensional theory of free electron lasers

In this paper, we present an analytical three-dimensional theory of free electron lasers. Under several assumptions, we arrive at an integral equation similar to earlier work carried out by Ching, Kim and Xie, but using a formulation better suited for the initial value problem of Coherent Electron Cooling. We use this model in later papers to obtain analytical results for gain guiding, as well as to develop a complete model of Coherent Electron Cooling.
Date: August 23, 2010
Creator: Webb, S. D.; Wang, G. & Litvinenko, V. N.
Object Type: Article
System: The UNT Digital Library
4-wave mixing for phase-matching free nonlinear optics in quantum cascade structures : LDRD 08-0346 final report. (open access)

4-wave mixing for phase-matching free nonlinear optics in quantum cascade structures : LDRD 08-0346 final report.

Optical nonlinearities and quantum coherences have the potential to enable efficient, high-temperature generation of coherent THz radiation. This LDRD proposal involves the exploration of the underlying physics using intersubband transitions in a quantum cascade structure. Success in the device physics aspect will give Sandia the state-of-the-art technology for high-temperature THz quantum cascade lasers. These lasers are useful for imaging and spectroscopy in medicine and national defense. Success may have other far-reaching consequences. Results from the in-depth study of coherences, dephasing and dynamics will eventually impact the fields of quantum computing, optical communication and cryptology, especially if we are successful in demonstrating entangled photons or slow light. An even farther reaching development is if we can show that the QC nanostructure, with its discrete atom-like intersubband resonances, can replace the atom in quantum optics experiments. Having such an 'artificial atom' will greatly improve flexibility and preciseness in experiments, thereby enhancing the discovery of new physics. This is because we will no longer be constrained by what natural can provide. Rather, one will be able to tailor transition energies and optical matrix elements to enhance the physics of interest. This report summarizes a 3-year LDRD program at Sandia National Laboratories exploring optical …
Date: October 1, 2010
Creator: Chow, Weng Wah; Wanke, Michael Clement; Allen, Dan G.; Yang, Zhenshan & Waldmueller, Ines
Object Type: Report
System: The UNT Digital Library
[5,10,15,20-Tetrakis(4-tolyl)porphyrin]-zinc(II) dichloromethane solvate (open access)

[5,10,15,20-Tetrakis(4-tolyl)porphyrin]-zinc(II) dichloromethane solvate

In the title complex, [Zn(C₄₈H₃₆N₄)]·CH₂Cl₂, the Znᴵᴵ atom lies on an inversion center and the dichloromethane solvent molecule is disordered around an inversion center.
Date: May 26, 2010
Creator: McGill, Sean; Nesterov, Vladimir N. & Gould, Stephanie L.
Object Type: Article
System: The UNT Digital Library
6-D weak-strong beam-beam simulation study of proton lifetime in presence of head-on beam-beam compensation in the RHIC (open access)

6-D weak-strong beam-beam simulation study of proton lifetime in presence of head-on beam-beam compensation in the RHIC

In this note we summarize the calculated particle loss of a proton bunch in the presence of head-on beam-beam compensation in the Relativistic Heavy Ion Collider (RHIC). To compensate the head-on beam-beam effect in the RHIC 250 GeV polarized proton run, we are introducing a DC electron beam with the same transverse profile as the proton beam to collide with the proton beam. Such a device is called an electron lens (e-lens). In this note we first present the optics and beam parameters and the tracking setup. Then we calculate and compare the particle loss of a proton bunch with head-on beam-beam compensation, phase advance of k{pi} between IP8 and the center of the e-lens and second order chromaticity correction. We scanned the proton beam's linear chromaticity, working point and bunch intensity. We also scanned the electron beam's intensity, transverse beam size. The effect of the electron-proton transverse offset in the e-lens was studied. In the study 6-D weak-strong beam-beam interaction model a la Hirata is used for proton collisions at IP6 and IP8. The e-lens is modeled as 8 slices. Each slice is modeled with as drift - (4D beam-beam kick) - drift.
Date: August 1, 2010
Creator: Luo, Y. & Fischer, W.
Object Type: Report
System: The UNT Digital Library

7.5 Minute Quadrangle Project

Presentation for the 2010 Depository Library Council Annual Meeting. This presentation discusses the 7.5 minute quadrangle project by the University of North Texas (UNT) Libraries' Digital Projects Unit and gives the background, goals, processes, challenges, and next steps.
Date: October 18, 2010
Creator: Phillips, Mark Edward
Object Type: Presentation
System: The UNT Digital Library

7 L Ranch Quadrangle

Satellite image topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:24,000
Date: 2010
Creator: Geological Survey (U.S.)
Object Type: Map
System: The Portal to Texas History
The “8(a) Program” for Small Businesses Owned and Controlled by the Socially and Economically Disadvantaged: Legal Requirements and Issues (open access)

The “8(a) Program” for Small Businesses Owned and Controlled by the Socially and Economically Disadvantaged: Legal Requirements and Issues

From Summary: "This report provides an overview of the Small Business Administration's (SBA's) Minority Small Business and Capital Ownership Development Program. Based on upon authorities given to the SBA by Sections 7(j) and 8(a) of the Small Business Act of 1958, as amended, this program is commonly known as the "8(a) Program."
Date: March 18, 2010
Creator: Luckey, J. R.
Object Type: Report
System: The UNT Digital Library
8(a) Program: Fourteen Ineligible Firms Received $325 Million in Sole-Source and Set-Aside Contracts (open access)

8(a) Program: Fourteen Ineligible Firms Received $325 Million in Sole-Source and Set-Aside Contracts

A letter report issued by the Government Accountability Office with an abstract that begins "The Small Business Administration (SBA) helps socially and economically disadvantaged small businesses gain access to federal contracting opportunities through its 8(a) program. To participate, firms must be at least 51 percent owned and controlled by an individual who meets SBA's criteria of socially and economically disadvantaged. The firm must also qualify as a small business. Once certified, 8(a) firms are eligible to receive sole-source and set-aside contracts for up to 9 years. GAO was asked to (1) determine whether ineligible firms are participating in the 8(a) program, (2) proactively test SBA's controls over the 8(a) application process, and (3) determine what vulnerabilities, if any, exist in SBA's fraud prevention system. To identify cases, GAO reviewed SBA data and complaints to GAO's fraud hotline. To perform its proactive testing, GAO created four bogus businesses and applied for 8(a) certification. GAO did not attempt to project the extent of fraud and abuse in the program."
Date: March 30, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
A 10-Hz Terawatt Class Ti:Sapphire Laser System: Development and Applications (open access)

A 10-Hz Terawatt Class Ti:Sapphire Laser System: Development and Applications

We developed a two stage Ti:Sapphire laser system to generate 16 mJ/80fs laser pulses at the pulse repetition rate of 10 Hz. The key deriver for the present design is implementing a highly efficient symmetric confocal pre-amplifier and employing a simple, inexpensive synchronization scheme relying only on a commercial digital delay-generator. We characterized the amplified pulses in spatial-, spectral-, and temporal-domains. The laser system was used to investigate various nonlinear optical processes, and to modify the optical properties of metal- and semiconductor-surfaces. We are currently building a third amplifier to boost the laser power to the multi-terawatt range.
Date: January 12, 2010
Creator: Sharma, A. K.; Smedley, J.; Tsang, T. & Rao, T.
Object Type: Article
System: The UNT Digital Library
11.424 Ghz Stripline Transversal Filter for Sub-Picosecond Bunch Timing Measurements (open access)

11.424 Ghz Stripline Transversal Filter for Sub-Picosecond Bunch Timing Measurements

Measurement of time-of-arrival or instantaneous longitudinal position is a fundamental beam diagnostic. We present results from a stripline transversal periodic coupler structure which forms the heart of a sub-ps beam timing detector. This filter structure approximates a sinx/x response in the frequency domain which corresponds to a limited pulse length response in the time domain. These techniques have been used extensively in beam feedback systems at 3 GHz center frequencies with operational single-shot resolutions of 200 fs [1]. We present a new design, based on a 11.424 GHz center frequency, which is intended to offer a factor of four improvement in time resolution. Two-dimensional electromagnetic simulation results are shown, and the design optimization approach leading to the final circuit implementation is illustrated. The prototype circuit has been fabricated on 64mil Rogers 4003 and lab frequency domain and time domain data are compared to the 2-D simulation results. Performance of the prototype circuit is shown with applicability to sub-ps beam measurements in LINAC and FEL applications.
Date: August 26, 2010
Creator: Van Winkle, D.; Young, A. & Fox, J. D.
Object Type: Article
System: The UNT Digital Library
[24-Hour Film Feast in memory of Esther Rolle dialogue with actor Antonio Fargas] captions transcript

[24-Hour Film Feast in memory of Esther Rolle dialogue with actor Antonio Fargas]

Video recording from The Black Academy of Arts and Letters recorded during the 2010 annual 24-Hour Film Feast in memory of actress Esther Rolle. The footage was shot during actor Antonio Fargas' dialogue on Rolle's pivotal work in American film and television held on Saturday, February 13th, 2010. The tape fades to black and then picks up with unrelated content around the 1:15:00 minute mark.
Date: February 13, 2010
Creator: King, Curtis & Fargas, Antonio
Object Type: Video
System: The UNT Digital Library
[24-Hour Film Feast with Melvin Van Peebles tape 1] captions transcript