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Broadcasting Board of Governors Should Provide Additional Information to Congress Regarding Broadcasting to Cuba (open access)

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
Federal Motor Carrier Safety Administration: Additional Actions Needed to Strengthen Grants Management (open access)

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
The Greensheet (Houston, Tex.), Vol. 42, No. 541, Ed. 1 Tuesday, December 13, 2011 (open access)

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 (open access)

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
Russia's December 2011 Legislative Election: Outcome and Implications (open access)

Russia's December 2011 Legislative Election: Outcome and Implications

This report discusses the December 2011 elections in Russia, including background information, the campaign, results and assessments of the election, implications for Russia and Prime Minister Vladimir Putin, and implications for U.S. interests. Congress may consider the implications of another Putin presidency, lagging democratization, and human rights abuses in Russia as it debates possible future foreign assistance and trade legislation and other aspects of U.S.-Russia relations.
Date: December 13, 2011
Creator: Nichol, Jim
Object Type: Report
System: The UNT Digital Library
Temporary Protected Status: Current Immigration Policy and Issues (open access)

Temporary Protected Status: Current Immigration Policy and Issues

This report is a brief overview of current policies regarding temporatry protected status (TPS), which is relief from removal under the Immigration and Nationality Act (INA). It includes information about humanitarian migrants, temporary protected status, other blanket forms of relief, nationalities receiving protections, and issues with TPS, as well as recent legislation.
Date: December 13, 2011
Creator: Wasem, Ruth Ellen & Ester, Karma
Object Type: Report
System: The UNT Digital Library
Veterans' Benefits: Pension Benefit Programs (open access)

Veterans' Benefits: Pension Benefit Programs

This report describes pension benefit programs offered by the Department of Veterans Affairs (VA), including the eligibility criteria and current benefit levels, and provides data on the number of pension beneficiaries in FY2010. The most current pension programs available (for those meeting the eligibility criteria on or after January 1, 1979) are the Improved Disability Pension for certain low-income veterans, the Improved Death Pension for certain low-income surviving spouses or children of veterans, as well as a special pension for Medal of Honor recipients.
Date: December 13, 2011
Creator: Scott, Christine & Davis, Carol D.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: GA-0896 (open access)

Texas Attorney General Opinion: GA-0896

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Whether certain kinds of electronic communication among members of the board of directors of a river authority constitute a violation of the Open Meetings Act, chapter 551 of the Government Code (RQ-0977-GA)
Date: December 13, 2011
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Toward TW-Level, Hard X-Ray Pulses at LCLS (open access)

Toward TW-Level, Hard X-Ray Pulses at LCLS

Coherent diffraction imaging of complex molecules such as proteins requires a large number (e.g., {approx} 10{sup 13}/pulse) of hard X-ray photons within a time scale of {approx} 10 fs or less. This corresponds to a peak power of {approx} 1 TW, much larger than that currently generated by LCLS or other proposed X-ray free electron lasers (FELs). We study the feasibility of producing such pulses using a LCLS-like, low charge electron beam, as will be possible in the LCLS-II upgrade project, employing a configuration beginning with a SASE amplifier, followed by a 'self-seeding' crystal monochromator, and finishing with a long tapered undulator. Our results suggest that TW-level output power at 8.3 keV is possible from a total undulator system length around 200 m. In addition power levels larger than 100 GW are generated at the third harmonic. We present a tapering strategy that extends the original 'resonant particle' formalism by optimizing the transport lattice to maximize optical guiding and enhance net energy extraction. We discuss the transverse and longitudinal coherence properties of the output radiation pulse and the expected output pulse energy sensitivity, both to taper errors and to power fluctuations on the monochromatized SASE seed.
Date: December 13, 2011
Creator: Fawley, W. M.; Frisch, J.; Huang, Z.; Jiao, Y.; Nuhn, H. D.; Pellegrini, C. et al.
Object Type: Article
System: The UNT Digital Library
Femtosecond X-ray Pulse Temporal Characterization in Free-Electron Lasers Using a Transverse Deflector (open access)

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
THIRD STATUS REPORT: TESTING OF AGED SOFTWOOD FIBERBOARD MATERIAL FOR THE 9975 SHIPPING PACKAGE (open access)

THIRD STATUS REPORT: TESTING OF AGED SOFTWOOD FIBERBOARD MATERIAL FOR THE 9975 SHIPPING PACKAGE

Samples have been prepared from a 9975 lower fiberboard subassembly fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. There is no clear trend thus far to indicate one material ages in a manner significantly different from the other material. Some softwood fiberboard properties degrade faster in some environments, while cane fiberboard degrades faster with regards to other properties and environments. Given the limited aging time accumulated to date in the elevated humidity environments, it is recommended that aging and testing of softwood fiberboard continue for another year. Post-conditioning data have been measured on samples from a single softwood fiberboard assembly, and baseline data are also available from a limited number of vendor-provided samples. This provides minimal information on the possible sample-to-sample variation exhibited by softwood fiberboard. Data to date are generally consistent with the range seen in cane fiberboard, but some portions of the data trends are skewed toward the lower end of that …
Date: December 13, 2011
Creator: Daugherty, W.
Object Type: Report
System: The UNT Digital Library
A Proposal for Study of Structure and Dynamics of Energy/Matter Based on Production of Gamma-Ray at SLAC Facility (open access)

A Proposal for Study of Structure and Dynamics of Energy/Matter Based on Production of Gamma-Ray at SLAC Facility

The success of this proposal will open new areas of Chemistry with antimatter: (1) new chemical dynamics; (2) exclusive production of parent ions by energy-tuning the positrons; (3) formation of antimatter compounds; (4) nano- and microscopic imaging of molecules, cells, and tumors (5) multi-positron systems and their thermodynamics and chemical kinetics. Also with o-Ps and p-Ps physics including speculations of dark mater (PAMELA & ATIC reported excesses in the e{sup +}e{sup -} cosmic rays).
Date: December 13, 2011
Creator: Decker, F. -J.; Krasnykh, Anatoly; Perelstein, M. & Shramenko, B.
Object Type: Article
System: The UNT Digital Library
Progress Report 2011: Understanding compound phase transitions in Heusler alloy giant magnetocaloric materials (open access)

Progress Report 2011: Understanding compound phase transitions in Heusler alloy giant magnetocaloric materials

Our goal is to gain insight into the fundamental physics that is responsible for magnetocaloric effects (MCE) and related properties at the atomic level. We are currently conducting a systematic study on the effects of atomic substitutions in Ni2MnGa-based alloys, and also exploring related full- and half-Heusler alloys, for example Ni-Mn-X (X=In, Sn, Sb), that exhibit a wide variety of interesting and potentially useful physical phenomena. It is already known that the magnetocaloric effect in the Heusler alloys is fundamentally connected to other interesting phenomena such as shape-memory properties. And the large magnetic entropy change in Ni2Mn0.75Cu0.25Ga has been attributed to the coupling of the first-order, martensitic transition with the second-order ferromagnetic—paramagnetic (FM-PM) transition. Our research to this point has focused on understanding the fundamental physics at the origin of these complex, compound phase transitions, and the novel properties that emerge. We synthesize the materials using a variety of techniques, and explore their material properties through structural, magnetic, transport, and thermo-magnetic measurements.
Date: December 13, 2011
Creator: Stadler, Shane
Object Type: Report
System: The UNT Digital Library
Thermal Acoustic Sensor for High Pulse Energy X-ray FEL Beams (open access)

Thermal Acoustic Sensor for High Pulse Energy X-ray FEL Beams

The pulse energy density of X-ray FELs will saturate or destroy conventional X-ray diagnostics, and the use of large beam attenuation will result in a beam that is dominated by harmonics. We present preliminary results at the LCLS from a pulse energy detector based on the thermal acoustic effect. In this type of detector an X-ray resistant material (boron carbide in this system) intercepts the beam. The pulse heating of the target material produces an acoustic pulse that can be detected with high frequency microphones to produce a signal that is linear in the absorbed energy. The thermal acoustic detector is designed to provide first- and second-order calorimetric measurement of X-ray FEL pulse energy. The first-order calorimetry is a direct temperature measurement of a target designed to absorb all or most of the FEL pulse power with minimal heat leak. The second-order measurement detects the vibration caused by the rapid thermoelastic expansion of the target material each time it absorbs a photon pulse. Both the temperature change and the amplitude of the acoustic signal are directly related to the photon pulse energy.
Date: December 13, 2011
Creator: Smith, T. J.; Frisch, J. C.; Kraft, E. M.; Loos, J. & Bentsen, G. S.
Object Type: Article
System: The UNT Digital Library
Final Technical Report, DE-SC0005319 (open access)

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
Observations and Modeling of Long Negative Laboratory Discharges: Identifying the Physics Important to an Electrical Spark in Air (open access)

Observations and Modeling of Long Negative Laboratory Discharges: Identifying the Physics Important to an Electrical Spark in Air

There are relatively few reports in the literature focusing on negative laboratory leaders. Most of the reports focus exclusively on the simpler positive laboratory leader that is more commonly encountered in high voltage engineering [Gorin et al., 1976; Les Renardieres Group, 1977; Gallimberti, 1979; Domens et al., 1994; Bazelyan and Raizer 1998]. The physics of the long, negative leader and its positive counterpart are similar; the two differ primarily in their extension mechanisms [Bazelyan and Raizer, 1998]. Long negative sparks extend primarily by an intermittent process termed a 'step' that requires the development of secondary leader channels separated in space from the primary leader channel. Long positive sparks typically extend continuously, although, under proper conditions, their extension can be temporarily halted and begun again, and this is sometimes viewed as a stepping process. However, it is emphasized that the nature of positive leader stepping is not like that of negative leader stepping. There are several key observational studies of the propagation of long, negative-polarity laboratory sparks in air that have aided in the understanding of the stepping mechanisms exhibited by such sparks [e.g., Gorin et al., 1976; Les Renardieres Group, 1981; Ortega et al., 1994; Reess et al., 1995; Bazelyan …
Date: December 13, 2011
Creator: Biagi, C J & Uman, M A
Object Type: Report
System: The UNT Digital Library
A Comprehensive Study of Nanometer Resolution of the IPBPM at ATF2 (open access)

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
Wildfire ignition resistant home design(WIRHD) program: Full-scale testing and demonstration final report. (open access)

Wildfire ignition resistant home design(WIRHD) program: Full-scale testing and demonstration final report.

The primary goal of the Wildfire ignition resistant home design(WIRHD) program was to develop a home evaluation tool that could assess the ignition potential of a structure subjected to wildfire exposures. This report describes the tests that were conducted, summarizes the results, and discusses the implications of these results with regard to the vulnerabilities to homes and buildings.
Date: December 13, 2011
Creator: Quarles, Stephen, L. & Sindelar, Melissa
Object Type: Report
System: The UNT Digital Library
First Beam to FACET (open access)

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 (open access)

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
Beam Dynamics Study of X-Band Linac Driven X-Ray FELS (open access)

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
Imaging gene expression in real-time using aptamers (open access)

Imaging gene expression in real-time using aptamers

Signal transduction pathways are usually activated by external stimuli and are transient. The downstream changes such as transcription of the activated genes are also transient. Real-time detection of promoter activity is useful for understanding changes in gene expression, especially during cell differentiation and in development. A simple and reliable method for viewing gene expression in real time is not yet available. Reporter proteins such as fluorescent proteins and luciferase allow for non-invasive detection of the products of gene expression in living cells. However, current reporter systems do not provide for real-time imaging of promoter activity in living cells. This is because of the long time period after transcription required for fluorescent protein synthesis and maturation. We have developed an RNA reporter system for imaging in real-time to detect changes in promoter activity as they occur. The RNA reporter uses strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags), which can be expressed from a promoter of choice. The tobramycin, neomycin and PDC RNA aptamers have been utilized for this system and expressed in yeast from the GAL1 promoter. The IMAGEtag RNA kinetics were quantified by RT-qPCR. In yeast precultured in raffinose containing media the GAL1 promoter responded faster …
Date: December 13, 2011
Creator: Shin, Il Chung
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Analysis of Vernier Scans during the PP2PP run in 2009 (pp at 100 GeV/beam) (open access)

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
X-Band Photo injector Beam Dynamics (open access)

X-Band Photo injector Beam Dynamics

SLAC is studying the feasibility of using an X-band RF photocathode gun to produce low emittance bunches for applications such as a mono-energetic MeV {gamma} ray source (in collaboration with LLNL) and a photoinjector for a compact FEL. Beam dynamics studies are being done for a configuration consisting of a 5.5-cell X-band gun followed by several 53-cell high-gradient X-band accelerator structures. A fully 3D program, ImpactT, is used to track particles taking into account space charge forces, short-range longitudinal and transverse wakefields, and the 3D rf fields in the structures, including the quadrupole component of the couplers. The effect of misalignments of the various elements, including the drive-laser, gun, solenoid and accelerator structures, are evaluated. This paper presents these results and estimates of the expected bunch emittance vs cathode gradient, and the effects of mixing between the fundamental and off-frequency longitudinal modes. An X-band gun at SLAC has been shown to operate reliably with a 200 MV/m acceleration gradient at the cathode, which is nearly twice the 115 MV/m acceleration gradient in the LCLS gun. The higher gradient should roughly balance the space charge related transverse emittance growth for the same bunch charge but provide a 3-4 times shorter bunch …
Date: December 13, 2011
Creator: Zhou, Feng; Adolphsen, Chris; Ding, Yuantao; Li, Zenghai & Vlieks, Arnold
Object Type: Article
System: The UNT Digital Library