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Office of Scientific & Technical Information Technical Reports
2,773
Congressional Research Service Reports
2,321
Government Accountability Office Reports
435
Texas State Publications
167
Texas State Auditor's Office: Reports
51
End of Term Publications
36
University Records
21
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14
Environmental Policy Collection
11
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111th Congress
92
Fiscal Year 2010
62
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36
82nd Legislature of Texas
18
Technical report (Texas Transportation Institute)
17
Fiscal Year 2011
14
Interim Report to the 82nd Texas Legislature
13
University of North Texas Investment Reports
12
Fiscal Year 2008
10
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121 More
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Naturally Occurring Groundwater Contamination in Texas
Report on a study to evaluate statewide water quality: "Groundwater quality in the state is greatly impacted by naturally occurring contamination derived from meteoric sources (precipitation), soils, and/or geologic sources [... which] contrast with anthropogenic substances that are added to the system through human activities. The objective of this study is to assess all naturally occurring and limiting chemical constituents that affect the quantity of fresh groundwater in Texas" (p. 1).
Date:
2010
Creator:
Reedy, Robert C. (Robert Challenger); Scanlon, Bridget R.; Walden, Steven & Strassberg, Gil
System:
The Portal to Texas History
NREL's Wind R&D Success Stories, National Wind Technology Center (NWTC) (Fact Sheet)
Wind energy research, development, and deployment have reduced the cost of large and small wind turbine technologies, increased wind energy system reliability and operability, lowered risk by validating performance and design, increased the understanding of the true impacts of wind energy on the U.S. electrical infrastructure, and expanded wind energy markets. A synopsis of research conducted on utility-scale wind turbines, small wind turbines, software, components, market development and grid integration are detailed.
Date:
January 1, 2010
Creator:
unknown
System:
The UNT Digital Library
Optimize Deployment of Renewable Energy Technologies for Government Agencies, Industrial Facilities, and Military Installations: NREL Offers Proven Tools and Resources to Reduce Energy Use and Improve Efficiency (Brochure)
The National Renewable Energy Lab provides expertise, facilities, and technical assistance to campuses, facilities, and government agencies to apply renewable energy and energy efficiency technologies.
Date:
January 1, 2010
Creator:
unknown
System:
The UNT Digital Library
Our Changing Planet: U.S. Climate Change Science Program Annual Report, 2010
Annual report of the U.S. Global Change Research Program documenting activities and research, goals for the upcoming year, proposed budget considerations, and other information about the organization for fiscal year 2010.
Date:
2010
Creator:
U.S. Global Change Research Program (2009-2010)
System:
The UNT Digital Library
Parallel algorithm strategies for circuit simulation.
Circuit simulation tools (e.g., SPICE) have become invaluable in the development and design of electronic circuits. However, they have been pushed to their performance limits in addressing circuit design challenges that come from the technology drivers of smaller feature scales and higher integration. Improving the performance of circuit simulation tools through exploiting new opportunities in widely-available multi-processor architectures is a logical next step. Unfortunately, not all traditional simulation applications are inherently parallel, and quickly adapting mature application codes (even codes designed to parallel applications) to new parallel paradigms can be prohibitively difficult. In general, performance is influenced by many choices: hardware platform, runtime environment, languages and compilers used, algorithm choice and implementation, and more. In this complicated environment, the use of mini-applications small self-contained proxies for real applications is an excellent approach for rapidly exploring the parameter space of all these choices. In this report we present a multi-core performance study of Xyce, a transistor-level circuit simulation tool, and describe the future development of a mini-application for circuit simulation.
Date:
January 1, 2010
Creator:
Thornquist, Heidi K.; Schiek, Richard Louis & Keiter, Eric Richard
System:
The UNT Digital Library
Paris Junior College Annual Report: 2010
Annual report for Paris Junior College in Paris, Texas discussing highlights of the school's students, faculty, and assciations.
Date:
2010~
Creator:
Paris Junior College
System:
The Portal to Texas History
Phase II Transport Model of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Revision 1
This document, the Phase II Frenchman Flat transport report, presents the results of radionuclide transport simulations that incorporate groundwater radionuclide transport model statistical and structural uncertainty, and lead to forecasts of the contaminant boundary (CB) for a set of representative models from an ensemble of possible models. This work, as described in the Federal Facility Agreement and Consent Order (FFACO) Underground Test Area (UGTA) strategy (FFACO, 1996; amended 2010), forms an essential part of the technical basis for subsequent negotiation of the compliance boundary of the Frenchman Flat corrective action unit (CAU) by Nevada Division of Environmental Protection (NDEP) and National Nuclear Security Administration Nevada Site Office (NNSA/NSO). Underground nuclear testing via deep vertical shafts was conducted at the Nevada Test Site (NTS) from 1951 until 1992. The Frenchman Flat area, the subject of this report, was used for seven years, with 10 underground nuclear tests being conducted. The U.S. Department of Energy (DOE), NNSA/NSO initiated the UGTA Project to assess and evaluate the effects of underground nuclear tests on groundwater at the NTS and vicinity through the FFACO (1996, amended 2010). The processes that will be used to complete UGTA corrective actions are described in the “Corrective Action Strategy” …
Date:
January 1, 2010
Creator:
Ruskuaff, Gregg
System:
The UNT Digital Library
Phonon engineering for nanostructures.
Understanding the physics of phonon transport at small length scales is increasingly important for basic research in nanoelectronics, optoelectronics, nanomechanics, and thermoelectrics. We conducted several studies to develop an understanding of phonon behavior in very small structures. This report describes the modeling, experimental, and fabrication activities used to explore phonon transport across and along material interfaces and through nanopatterned structures. Toward the understanding of phonon transport across interfaces, we computed the Kapitza conductance for {Sigma}29(001) and {Sigma}3(111) interfaces in silicon, fabricated the interfaces in single-crystal silicon substrates, and used picosecond laser pulses to image the thermal waves crossing the interfaces. Toward the understanding of phonon transport along interfaces, we designed and fabricated a unique differential test structure that can measure the proportion of specular to diffuse thermal phonon scattering from silicon surfaces. Phonon-scale simulation of the test ligaments, as well as continuum scale modeling of the complete experiment, confirmed its sensitivity to surface scattering. To further our understanding of phonon transport through nanostructures, we fabricated microscale-patterned structures in diamond thin films.
Date:
January 1, 2010
Creator:
Aubry, Sylvie; Friedmann, Thomas Aquinas; Sullivan, John Patrick; Peebles, Diane Elaine; Hurley, David H.; Shinde, Subhash L. et al.
System:
The UNT Digital Library
R&D ERL: 5 Cell 704 MHz SRF Cavity
One of the key components for the superconducting RF Energy Recovery Linac, (ERL) under development in the Collider Accelerator Department at Brookhaven National Laboratory, is the Linac cavity and cryomodule. The cavity is a 5 cell accelerating cavity designed to operate at 703.75 MHz, and to accelerate 2 MeV electrons from the photoinjector up to 15-20 MeV, allow them to make a single pass around the ERL loop and then decelerate them back down to 2 MeV prior to sending them to the beam dump. This cavity was designed by Rama Calaga and Ilan Ben-Zvi at BNL and fabricated by Advanced Energy Systems in Medford, NY. The cavity was then delivered to Thomas Jefferson Laboratory in VA for chemical processing, testing and assembly of the hermetic string assembly suitable for shipment back to BNL. Once at BNL it was built into a complete cryomodule, installed in the ERL test facility and commissioned. This paper will review the key components of the cavity and cryomodule and discuss the present status of the cryomodule commissioning. The BNL 5 cell accelerating cavity has been designed for use in our high average current Energy Recovery Linac, a proof of principle machine to demonstrate key …
Date:
January 1, 2010
Creator:
Burrill, A.
System:
The UNT Digital Library
R&D ERL: Beam Dump
As its name suggests, the beam dump is where electron bunches end up while depositing energy unrecovered by the ERL. The process of removing unrecovered energy must not have any adverse effects on the ERL system like outgassing or backstreaming electrons. Electron beam dumps are widely used in various applications ranging from radiation generating devices like klystrons and traveling wave tubes to EBIS sources and electron beam coolers, as well as to large machines that include LINACs and electron colliders. Energy of discarded electrons range from a few electron volts to 10's of GeV. This beam dump has a couple of unique issues that determine the design concept: cascade showers and seals that can withstand high radiation dosage.
Date:
January 1, 2010
Creator:
Hershcovitch, A.
System:
The UNT Digital Library
R&D ERL: Controls System
This paper examines the equipment and software from which the controls system interface for the Energy Recovery Linac (ERL) will be implemented at the Brookhaven National Laboratory.
Date:
January 1, 2010
Creator:
Hoff, L. & Jamilkowski, J.
System:
The UNT Digital Library
R&D ERL: Cryogenic System
The ERL cryogenic system will supply cooling to a super-conducting RF (SCRF) gun and the 5-cell super-conducting RF cavity system that need to be held cold at 2K. The engineering of the cavity cryomodules were carried out by AES in collaboration with BNL. The 2K superfluid bath is produced by pumping on the bath using a sub-atmospheric warm compression system. The cryogenic system makes use of mainly existing equipment relocated from other facilities: a 300W 4.5K coldbox, an 45 g/s screw compressor, a 3800 liter liquid helium storage dewar, a 170 m{sup 3} warm gas storage tank, and a 40,000 liter vertical low pressure liquid nitrogen storage dewar. An existing wet expander obtained from another facility has been added to increase the plant capacity. In order to deliver the required 3 to 4 bar helium to the cryomodules while using up stored liquid capacity at low pressure, a new subcooler will be installed to function as the capacity transfer device. A 2K to 4K recovery heat exchanger is also implemented for each cryomodule to recover refrigeration below 4K, thus maximizing 2K cooling capacity with the given sub-atmospheric pump. No 4K-300K refrigeration recovery is implemented at this time of the returning …
Date:
January 1, 2010
Creator:
Than, R.
System:
The UNT Digital Library
R&D ERL: Diagnostics
The Energy Recovery Linac (ERL) prototype project is currently under development at the Brookhaven National Laboratory. The ERL is expected to demonstrate energy recovery of high intensity beams with a current of up to a few hundred milliamps, while preserving the emittance of bunches with a charge of a few nanocoulombs produced by a high current SRF gun. To successfully accomplish this task the machine will include beam diagnostics that will be used for accurate characterization of the three dimensional beam phase space at the injection and recirculation energies, transverse and longitudinal beam matching, orbit alignment, beam current measurement, and machine protection. This report outlines requirements on the ERL diagnostics and describes its setup and modes of operation. The BNL Prototype ERL is an R&D effort aimed at reducing risks and costs associated with the proposed RHIC II electron cooler and eRHIC collider. The ERL will serve as a test bed for developing and testing instrumentation and studying physics and technological issues relevant to very high current ERL's. The prototype ERL, mated to a high current SRF gun, is expected to demonstrate production and energy recovery of high intensity, low emittance beams with a current of up to a few …
Date:
January 1, 2010
Creator:
Gassner, D.
System:
The UNT Digital Library
R&D ERL: HOM Absorbers
Several future accelerator projects at the Relativistic Heavy Ion Collider (RHIC) are based on Energy Recovery Linacs (ERL) with high-charge high-current electron beams. Their stable operation mandates effective higher-order-mode (HOM) damping. The development of HOM dampers for these projects is pursued actively at this laboratory. A strong HOM damping was experimentally demonstrated both at room- and at superconducting- (SC) temperatures in a prototype R&D five-cell niobium SRF cavity with ferrite dampers. A novel type of ferrite damper over a ceramic break for a R&D SRF electron gun also was developed. For future SRF linacs longer cryomodules comprising of multiple superconducting cavities with reasonably short transitions between them are planned. In such a configuration, the dampers, located closer to the cavities, will be at cryogenic temperatures; this will impose additional constraints and complications. Two room-temperature mock-up five-cell copper cavities were used to study various damper configurations. This paper presents results of simulations and measurements for several configurations.
Date:
January 1, 2010
Creator:
Hahn, H.; Ben-Zvi, Ilan; Calaga, R.; Hammons, L.; Litvinenko, V. N. & Xu, W.
System:
The UNT Digital Library
R&D ERL: HTS Solenoid
An innovative feature of the ERL project is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The HTS solenoid design offers many advantages because of several unique design features. Typically the solenoid is placed outside the cryostat which means that the beam gets significantly defused before a focusing element starts. In the current design, the solenoid is placed inside the cryostat which provides an early focusing structure and thus a significant reduction in the emittance of the electron beam. In addition, taking full advantage of the high critical temperature of HTS, the solenoid has been designed to reach the required field at {approx}77 K, which can be obtained with liquid nitrogen. This significantly reduces the cost of testing and allows a variety of critical pre-tests which would have been prohibitively expensive at 4 K in liquid helium because of the additional requirements of cryostat and associated facilities.
Date:
January 1, 2010
Creator:
Gupta, R.; Muratore, J. & Plate, S.
System:
The UNT Digital Library
R&D ERL: Machine Protection System
The Machine Protection System (MPS) is a device-safety system that is designed to prevent damage to hardware by generating interlocks, based upon the state of input signals generated by selected sub-system. It exists to protect key machinery such as the 50 kW and 1 MW RF Systems. When a fault state occurs, the MPS is capable of responding with an interlock signal within several microseconds. The Machine Protection System inputs are designed to be fail-safe. In addition, all fault conditions are latched and time-stamped. The ERL MPS is based on a National Instruments hardware platform, and is programmed by utilizing National Instruments development environment for a visual programming language.
Date:
January 1, 2010
Creator:
Altinbas, Z.
System:
The UNT Digital Library
R&D ERL: Magnet
The BNL prototype ERL is the major experimental research and development effort towards RHIC II, the electron cooling project for RHIC. The objective is to reduce the risk and costs of the RHIC II project, as well as developing and demonstrating the electron beam parameters required for electron cooling. The prototype will also serve as a test bed for studying issues relevant to very high current ERLs. All quadrupole and dipole magnets are of the warm bore variety. All magnets are to be accurately CNC machined and will be installed on similarly machined bases. A portion of the ring will be mounted on a movable gantry with a total stroke of plus/minus 5cm.
Date:
January 1, 2010
Creator:
Mahler, G.
System:
The UNT Digital Library
R&D ERL: Photocathode Deposition and Transport System
The purpose of the photocathode deposition and transport system is to (1) produce a robust, high yield multialkali photocathode and (2) have a method of transporting the multialkali photocathode for insertion into a super conducting RF electron gun. This process is only successful if a sufficient quantum efficiency lifetime of the cathode, which is inserted in the SRF electron gun, is maintained. One important element in producing a multialkali photocathode is the strict vacuum requirements of 10{sup -11} torr to assure success in the production of longlived photocathodes that will not have their QE or lifetime depleted due to residual gas poisoning in a poor vacuum. A cutaway view of our third generation deposition system is shown in figure 1. There are certain design criteria and principles required. One must be able to install, remove, rejuvenate and replace a cathode without exposing the source or cathode to atmosphere. The system must allow one to deposit Cs, K, and Sb on a cathode tip surface at pressures in the 10{sup -10} to 10{sup -9} torr range. The cathode needs to be heated to as high as 850 C for cleaning and maintained at 130 C to 150 C during deposition. There …
Date:
January 1, 2010
Creator:
Pate, D.; Ben-Zvi, Ilan; Rao, T.; Burrill, R.; Todd, R.; Smedley, J. et al.
System:
The UNT Digital Library
R&D ERL: Power Supplies
A magnet power supply system has been developed to meet the field requirements of the ERL in a compact and cost effective fashion.
Date:
January 1, 2010
Creator:
Lambiase, R.
System:
The UNT Digital Library
R&D ERL: SRF Electron Gun
When the BNL high current ERL was first envisioned the choice of injector went through several iterations before concluding that an SRF injector was the appropriate choice for the task at hand. The design requirements were quite stringent as the injector had to be designed to reach currents never before achieved in any injector. The overall goal was to design an injector capable of delivering up to 0.5 Ampere at 703.75 MHz. This criteria was set based on the need to demonstrate high average current energy recovery at the ERL so that future machines could be designed and built with confidence in the injector. For the ERL the injector needs to be capable of accelerating electrons to 2-2.5 MeV with charges ranging from 0.7 to 5 nC per bunch depending on the operational parameters being studied. These criteria led to a 1/2 cell photoinjector designed to accommodate a demountable photocathode utilizing a novel quarter wave choke joint for the cathode insertion mechanism. The cavity requires a total of 1 MW of power coupled to the beam in order to meet the high current application, necessitating two 500 kW RF power couplers. This AP note will review the overall physics design …
Date:
January 1, 2010
Creator:
Burrill, A.
System:
The UNT Digital Library
R&D ERL: Vacuum
The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the {approx}10{sup -9} torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2{sup o}K is reduced to low 10{sup -11} torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in …
Date:
January 1, 2010
Creator:
Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A. & Todd, R.
System:
The UNT Digital Library
Renewable Energy Prices in State-Level Feed-in Tariffs: Federal Law Constraints and Possible Solutions
State legislatures and state utility commissions trying to attract renewable energy projects are considering feed-in tariffs, which obligate retail utilities to purchase electricity from renewable producers under standard arrangements specifying prices, terms, and conditions. The use of feed-in tariffs simplifies the purchase process, provides revenue certainty to generators, and reduces the cost of financing generating projects. However, some argue that federal law--including the Public Utility Regulatory Policies Act of 1978 (PURPA) and the Federal Power Act of 1935 (FPA)--constrain state-level feed-in tariffs. This report seeks to reduce the legal uncertainties for states contemplating feed-in tariffs by explaining the constraints imposed by federal statutes. It describes the federal constraints, identifies transaction categories that are free of those constraints, and offers ways for state and federal policymakers to interpret or modify existing law to remove or reduce these constraints. This report proposes ways to revise these federal statutes. It creates a broad working definition of a state-level feed-in tariff. Given this definition, this report concludes there are paths to non-preempted, state-level feed-in tariffs under current federal law.
Date:
January 1, 2010
Creator:
Hempling, S.; Elefant, C.; Cory, K. & Porter, K.
System:
The UNT Digital Library
Report of the 2nd National Ecosystem Modeling Workshop (NEMoW II) : Bridging the Credibility Gap - Dealing with Uncertainty in Ecosystem Models
The following document addresses the terms of reference (TOR) such that a group of scientists forming the National Ecosystem Modeling Workshops (NEMoWs) could explore the facets of ecosystem model (EM) uncertainty and make pragmatic suggestions of how the NMFS could proceed in its EM endeavors by dealing with uncertainty using a suite of "best practices" recommended herein.
Date:
January 2010
Creator:
Link, J. S.; Ihde, T. F.; Townsend, H. M.; Osgood, K. E.; Schirripa, M. J.; Kobayashi, D. R. et al.
System:
The UNT Digital Library
Report on Texas Bridges as of September 2010
This report describes bridges and their conditions in Texas. The report provides information on the types of bridges, integrity of them, and prioritizes their need for upgrade.
Date:
2010
Creator:
Texas. Department of Transportation.
System:
The Portal to Texas History