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The Black Academy of Arts and Letters Records
226
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128
Documenting Plate Waste in Middle School Cafeterias Using Digital Still Photography
117
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107
Congressional Research Service Reports
80
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47
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46
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31
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1 - 24 of
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Advancing Aviation Security
None
Date:
December 13, 2011
Creator:
Martz, H E; Roberson, G P; Azevedo, S G & Kallman, J S
Object Type:
Report
System:
The UNT Digital Library
Aligning National Approaches to Digital Preservation: Community Briefing on the ANADP 2011 Summit
Presentation for the 2011 Coalition of Networked Information (CNI) meeting discussing the Aligning National Approaches to Digital Preservation Summit, held in the capital of Estonia in May 2011.
Date:
December 13, 2011
Creator:
Halbert, Martin
Object Type:
Presentation
System:
The UNT Digital Library
The Altus Times (Altus, Okla.), Vol. 112, No. 176, Ed. 1 Tuesday, December 13, 2011
Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date:
December 13, 2011
Creator:
Bush, Michael
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
Analysis of Vernier Scans during the PP2PP run in 2009 (pp at 100 GeV/beam)
At the end of RHIC's 2009 operation a dedicated run for the PP2PP experiment (part of the STAR experiment) took place from Jun 29 to Jul 06 2009. Polarized protons were accelerated to 100 GeV using ramp-file pp100-90pp2pp with a {beta}* = 22 m in IR6. Since only transverse polarization was required no rotator ramp was in use. The PP2PP experiment consists mainly of two Roman Pot detectors (one horizontal and one vertical) on either side of IR6 in the outgoing-beam arms between the Q3 and Q4 magnets. The yellow pots are in sector 5, the blue ones in sector 6. Roman Pot type detectors are installed inside the beampipe causing an accelerator safety concern. To address this concern there is a limit to the allowable total beam current in the machine while Roman Pots are enabled to move closer to the beam. This limit was set to a motion limit of 5 mm from the center of the beampipe and 50 {center_dot} 10{sup 11} beam current per ring. In order to reduce the background in the detectors, beams were scraped using the RHIC collimator system prior to moving the pots closer. This was typically repeated several times throughout a …
Date:
December 13, 2011
Creator:
Drees, A.
Object Type:
Report
System:
The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 91, No. 244, Ed. 1 Tuesday, December 13, 2011
Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date:
December 13, 2011
Creator:
Gray, Janie
Object Type:
Newspaper
System:
The Portal to Texas History
Beam Dynamics Study of X-Band Linac Driven X-Ray FELS
Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described briefly. During the last 40 years, the photon wavelengths from linac driven FELs have been pushed shorter by increasing the electron beam energy and adopting shorter period undulators. Recently, the wavelengths have reached the X-ray range, with FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source) successfully providing users with soft and hard X-rays, respectively. FLASH uses a 1.2 GeV L-band (1.3 GHz) superconducting linac driver and can deliver 10-70 fs FWHM long photon pulses in a wavelength range of 44 nm to 4.1 nm. LCLS uses the last third of the SLAC 3 km S-band (2.856 GHz) normal-conducting linac to produce 3.5 GeV to 15 GeV bunches to generate soft and hard X-rays with good spatial coherence at wavelengths from 2.2 nm to …
Date:
December 13, 2011
Creator:
Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T. O.; Wu, J. & Sun, Y.
Object Type:
Article
System:
The UNT Digital Library
Broadcasting Board of Governors Should Provide Additional Information to Congress Regarding Broadcasting to Cuba
Correspondence issued by the Government Accountability Office with an abstract that begins ""
Date:
December 13, 2011
Creator:
United States. Government Accountability Office.
Object Type:
Text
System:
The UNT Digital Library
A Comprehensive Study of Nanometer Resolution of the IPBPM at ATF2
High-resolution beam position monitors (IPBPMs) have been developed in order to measure the electron beam position at the focus point of ATF2 to a few nanometers in the vertical plane. To date, the IPBPM system has operated in test mode with a highest demonstrated resolution of 8.7 nm in the ATF extraction line during 2008. After expected noise source calculations there still remains 7.9 nm of noise of unexplained origin. We summarize the experimental work on the IPBPM system since this measurement and outline the possible origins of these sources. We then present a study plan to be performed at the ATF2 facility designed to identify and to improve the resolution performance and comment on the expected ultimate resolution of this system. The Accelerator Test Facility 2 (ATF2) is a test beamline for ILC final focus system in the framework of the ATF international collaboration which was constructed to extend the extraction line at ATF, located at KEK, Japan. There are two goals of the ATF2: firstly to demonstrate focusing to 37 nm vertical beam size, secondly to achieve a few nanometer level beam orbit stability at the focus point in the vertical plane. High-resolution beam position monitors (IPBPMs) for …
Date:
December 13, 2011
Creator:
Kim, Y. I.; Park, H.; U., /Kyungpook Natl.; Boogert, S. T.; /Oxford U., JAI; Frisch, J. et al.
Object Type:
Article
System:
The UNT Digital Library
DART takes next steps to direct DFW Airport connection
News release about DART's planned extension of its Orange Line to the DFW International Airport.
Date:
December 13, 2011
Creator:
Lyons, Morgan & Ball, Mark
Object Type:
Text
System:
The Portal to Texas History
Dynamic Aperture and Tolerances for PEP-X Ultimate Storage Ring Design
A lattice for the PEP-X ultimate storage ring light source, having 11 pm-rad natural emittance at a beam energy of 4.5 GeV at zero current, using 90 m of damping wiggler and fitting into the existing 2.2-km PEP-II tunnel, has been recently designed. Such a low emittance lattice requires very strong sextupoles for chromaticity correction, which in turn introduce strong non-linear field effects that limit the beam dynamic aperture. In order to maximize the dynamic aperture we choose the cell phases to cancel the third and fourth order geometric resonances in each 8-cell arc. Four families of chromatic sextupoles and six families of geometric (or harmonic) sextupoles are added to correct the chromatic and amplitude-dependent tunes. To find the best settings of the ten sextupole families, we use a Multi-Objective Genetic Optimizer employing elegant to optimize the beam lifetime and dynamic aperture simultaneously. Then we evaluate dynamic aperture reduction caused by magnetic field multipole errors, magnet fabrication errors and misalignments. A sufficient dynamic aperture is obtained for injection, as well as workable beam lifetime.
Date:
December 13, 2011
Creator:
Borland, M.; /Argonne; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; /SLAC et al.
Object Type:
Article
System:
The UNT Digital Library
Electron Bunch Profile Diagnostics in the Few FS Regime Using Coherent Smith-Purcell Radiation
The rapid developments in the field of laser-driven particle acceleration hold the prospect of intense, highly relativistic electron bunches that are only a few fs long. The determination of the temporal profile of such bunches presents new challenges. The use of a radiative process such as Smith-Purcell radiation (SPR), is particularly promising in this respect. In this technique the beam is made to radiate a small amount of e/m radiation and the temporal profile is reconstructed from the measured spectral distribution of the radiation. We summarise the advantages of SPR and present the design parameters and preliminary results of the experiments at the FACET facility at SLAC. We also discuss a new approach to the problem of the recovery of the 'missing phase', which is essential for the accurate reconstruction of the temporal bunch profile.
Date:
December 13, 2011
Creator:
Bartolini, R.; Source, /Oxford U. /Diamond Light; Clarke, C.; /SLAC; Delerue, N.; /Orsay, LAL et al.
Object Type:
Article
System:
The UNT Digital Library
[Email from Carl Parker to Jack and George, Mike Anglin, Buddy Mullino, and Rob Emery, December 13, 2011]
Email from Carl Parker to Jack and George, Buddy Mullino, Mike Anglin, and Rob Emery discussing the upcoming Dallas Way board meeting.
Date:
December 13, 2011
Creator:
Parker, Carl
Object Type:
Letter
System:
The UNT Digital Library
ESTB: A New Beam Test Facility at SLAC
None
Date:
December 13, 2011
Creator:
Hast, C.; Fieguth, T.; Iverson, R.; Jaros, J.; Jobe, K.; Keller, L. et al.
Object Type:
Article
System:
The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, December 13, 2011
Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date:
December 13, 2011
Creator:
DeSilver, Debi
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
FACET: The New User Facility at SLAC
FACET (Facility for Advanced Accelerator and Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. Its high power electron and positron beams make it a unique facility, ideal for beam-driven Plasma Wakefield Acceleration studies. The first 2 km of the SLAC linac produce 23 GeV, 3.2 nC electron and positron beams with short bunch lengths of 20 {mu}m. A final focusing system can produce beam spots 10 {mu}m wide. User-aided Commissioning took place in summer 2011 and FACET will formally come online in early 2012. We present the User Facility, the current features, planned upgrades and the opportunities for further experiments. Accelerators are our primary tool for discovering the fundamental laws to the universe. Each new frontier we probe requires a new, more powerful method. Accelerators are therefore increasing in size and cost. The future of this field requires new accelerating techniques that can reach the high energies required over shorter distances. New concepts for high gradient acceleration include utilizing the wakes in plasma and dielectric and metallic structures. FACET was built to provide a test bed for novel accelerating concepts with its high charge and highly compressed beams. As a test facility unlike any other, it …
Date:
December 13, 2011
Creator:
Clarke, C. I.; Decker, F. J.; Erikson, R.; Hast, C.; Hogan, M. J.; Iverson, R. et al.
Object Type:
Article
System:
The UNT Digital Library
Federal Motor Carrier Safety Administration: Additional Actions Needed to Strengthen Grants Management
A letter report issued by the Government Accountability Office with an abstract that begins "What GAO Found"
Date:
December 13, 2011
Creator:
United States. Government Accountability Office.
Object Type:
Report
System:
The UNT Digital Library
Femtosecond X-ray Pulse Temporal Characterization in Free-Electron Lasers Using a Transverse Deflector
We propose a novel method to characterize the temporal duration and shape of femtosecond x-ray pulses in a free-electron laser (FEL) by measuring the time-resolved electron-beam energy loss and energy spread induced by the FEL process, with a transverse radio-frequency deflector located after the undulator. Its merits are simplicity, high resolution, wide diagnostic range, and non-invasive to user operation. When the system is applied to the Linac Coherent Light Source, the first hard x-ray free-electron laser in the world, it can provide single-shot measurements on the electron beam and x-ray pulses with a resolution on the order of 1-2 femtoseconds rms.
Date:
December 13, 2011
Creator:
Ding, Y.; Behrens, C.; Emma, P.; Frisch, J.; Huang, Z.; Loos, H. et al.
Object Type:
Article
System:
The UNT Digital Library
Final Report of a CRADA Between Pacific Northwest National Laboratory and the General Motors Company (CRADA No. PNNL/271): “Degradation Mechanisms of Urea Selective Catalytic Reduction Technology”
Diesel engines can offer substantially higher fuel efficiency, good driving performance characteristics, and reduced carbon dioxide (CO2) emission compared to stoichiometric gasoline engines. Despite the increasing public demand for higher fuel economy and reduced dependency on imported oil, however, meeting the stringent emission standards with affordable methods has been a major challenge for the wide application of these fuel-efficient engines in the US market. The selective catalytic reduction of NOx by urea (urea-SCR) is one of the most promising technologies for NOx emission control for diesel engine exhausts. To ensure successful NOx emission control in the urea-SCR technology, both a diesel oxidation catalyst (DOC) and a urea-SCR catalyst with high activity and durability are critical for the emission control system. Because the use of this technology for light-duty diesel vehicle applications is new, the relative lack of experience makes it especially challenging to satisfy the durability requirements. Of particular concern is being able to realistically simulate actual field aging of the catalyst systems under laboratory conditions, which is necessary both as a rapid assessment tool for verifying improved performance and certifiability of new catalyst formulations. In addition, it is imperative to develop a good understanding of deactivation mechanisms to help …
Date:
December 13, 2011
Creator:
Kim, Do Heui; Lee, Jong H.; Peden, Charles HF; Howden, Ken; Kim, Chang H.; Oh, Se H. et al.
Object Type:
Report
System:
The UNT Digital Library
Final Technical Report, DE-SC0005319
The CEHMM algae to biodiesel project is a research and development endeavor investigating renewable fuels and a host of high-value co-products from the propagation, harvesting, and extraction of oil from a salt/brine water algae in open raceway ponds. Use of algae as renewable fuel feedstock complementary to petroleum diesel has great potential to make fuels and a host of valuable co-products, thereby reducing American dependence on foreign oil, sequestering carbon, and providing attractive multi-market returns for potential investors. This project is a green energy project thereby supporting the national agenda of a clean and renewable source of energy and will not compete with traditional food crops.
Date:
December 13, 2011
Creator:
Douglas C. Lynn, Executive Director
Object Type:
Report
System:
The UNT Digital Library
First Beam to FACET
The SLAC 3km linear electron accelerator has been reconfigured to provide a beam of electrons to the new Facility for Advanced Accelerator Experimental Tests (FACET) while simultaneously providing an electron beam to the Linac Coherent Light Source (LCLS). On June 23, 2011, the first electron beam was transported through this new facility. Commissioning of FACET is in progress. On June 23, 2011, an electron beam was successfully transported through the new FACET system to a dump in Sector 20 in the linac tunnel. This was achieved while the last third of the linac, operating from the same control room, but with a separate injector system, was providing an electron beam to the Linac Coherent Light Source (LCLS), demonstrating that concurrent operation of the two facilities is practical. With the initial checkout of the new transport line essentially complete, attention is now turning toward compressing the electron bunches longitudinally and focusing them transversely to support a variety of accelerator science experiments.
Date:
December 13, 2011
Creator:
Erickson, R.; Clarke, C.; Colocho, W.; Decker, F. -J.; Hogan, M.; Kalsi, S. et al.
Object Type:
Article
System:
The UNT Digital Library
Gamma-Ray Observations of the Supernova Remnant RX J0852.0-4622 with the Fermi LAT
We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.0-4622 with the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope. In the Fermi LAT data, we find a spatially extended source at the location of the SNR. The extension is consistent with the SNR size seen in other wavelengths such as X-rays and TeV gamma rays, leading to the identification of the gamma-ray source with the SNR. The spectrum is well described as a power law with a photon index of {Lambda} = 1.85 {+-} 0.06 (stat){sub -0.19}{sup +0.18} (sys), which smoothly connects to the H.E.S.S. spectrum in the TeV energy band. We discuss the gamma-ray emission mechanism based on multiwavelength data. The broadband data can be fit well by a model in which the gamma rays are of hadronic origin. We also consider a scenario with inverse Compton scattering of electrons as the emission mechanism of the gamma rays. Although the leptonic model predicts a harder spectrum in the Fermi LAT energy range, the model can fit the data considering the statistical and systematic errors.
Date:
December 13, 2011
Creator:
Tanaka, T.; Allafort, A.; /Stanford U., HEPL /KIPAC, Menlo Park; Ballet, J.; /Saclay; Funk, S. et al.
Object Type:
Article
System:
The UNT Digital Library
Gas atomized precursor alloy powder for oxide dispersion strengthened ferritic stainless steel
Gas atomization reaction synthesis (GARS) was employed as a simplified method for producing precursor powders for oxide dispersion strengthened (ODS) ferritic stainless steels (e.g., Fe-Cr-Y-(Ti,Hf)-O), departing from the conventional mechanical alloying (MA) process. During GARS processing a reactive atomization gas (i.e., Ar-O{sub 2}) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 150 nm) metastable Cr-enriched oxide layer that was used as a vehicle for solid-state transport of O into the consolidated microstructure. In an attempt to better understand the kinetics of this GARS reaction, theoretical cooling curves for the atomized droplets were calculated and used to establish an oxidation model for this process. Subsequent elevated temperature heat treatments, which were derived from Rhines pack measurements using an internal oxidation model, were used to promote thermodynamically driven O exchange reactions between trapped films of the initial Cr-enriched surface oxide and internal Y-enriched intermetallic precipitates. This novel microstructural evolution process resulted in the successful formation of nano-metric Y-enriched dispersoids, as confirmed using high energy X-ray diffraction and transmission electron microscopy (TEM), equivalent to conventional ODS alloys from MA powders. The thermal …
Date:
December 13, 2011
Creator:
Rieken, Joel
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
The Greensheet (Houston, Tex.), Vol. 42, No. 541, Ed. 1 Tuesday, December 13, 2011
Free weekly newspaper that includes business and classified advertising.
Date:
December 13, 2011
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History
The Greensheet (Houston, Tex.), Vol. 42, No. 542, Ed. 1 Tuesday, December 13, 2011
Free weekly newspaper that includes business and classified advertising.
Date:
December 13, 2011
Creator:
unknown
Object Type:
Newspaper
System:
The Portal to Texas History