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Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials (open access)

Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials

Using a beam of tagged 14.1 MeV neutrons to probe for the presence of fissionable materials, we have measured n-γ-γ coincidences from depleted uranium (DU). The multiple coincidence rate is substantially above that measured from lead, tungsten, and iron. The presence of coincidences involving delayed gammas in the DU time spectra provides a signature for fissionable materials that is distinct from non-fissionable ones. In addition, the information from the tagged neutron involved in the coincidence gives the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is more compact and that produces much less radiation than other solutions.
Date: August 6, 2008
Creator: J.P. Hurley, R.P. Keegan, J.R. Tinsley, R. Trainham, and S.C. Wilde
Object Type: Article
System: The UNT Digital Library
Photodeposition of Pt on Colloidal CdS and CdSe/CdS Semiconductor Nanostructures (open access)

Photodeposition of Pt on Colloidal CdS and CdSe/CdS Semiconductor Nanostructures

Semiconductor photocatalysis has been identified as a promising avenue for the conversion of solar energy into environmentally friendly fuels, most notably by the production of hydrogen from water.[1-5] Nanometer-scale materials in particular have attracted considerable scientific attention as the building blocks for light-harvesting applications.[6,7] Their desirable attributes include tunability of the optical properties with size, amenability to relatively inexpensive low-temperature processing, and a high degree of synthetic sophistication leading to increasingly complex and multi-functional architectures. For photocatalysis in particular, the high surface-to-volume ratios in nanoscale materials should lead to an increased availability of carriers for redox reactions on the nanoparticle surface. Recombination of photoexcited carriers directly competes with photocatalytic activity.[3] Charge separation is often achieved with multi-component heterostructures. An early example is the case of TiO2 powders functionalized with Pt and RuO2 particles, where photoexcited electrons are transferred to Pt (the reduction site) and holes to RuO2 (the oxidation site).[8] More recently, many colloidally synthesized nanometer-scale metal-semiconductor heterostructures have been reported.[7,9,10] A majority of these structures are made by thermal methods.[7,10] We have chosen to study photochemical formation of metal-semiconductor heterostructures. The detailed understanding of the mechanisms involved in photodeposition of metals on nanometer-scale semiconductors is necessary to enable a …
Date: August 6, 2008
Creator: Dukovic, Gordana; Merkle, Maxwell G.; Nelson, James H.; Hughes, Steven M. & Alivisatos, A. Paul
Object Type: Article
System: The UNT Digital Library
Actinic EUV mask inspection beyond 0.25 NA (open access)

Actinic EUV mask inspection beyond 0.25 NA

Operating at EUV wavelengths, the SEMATECH Berkeley Actinic Inspection Tool (AIT) is a zoneplate microscope that provides high quality aerial image measurements in routine operations for SEMATECH member companies. We have upgraded the optical performance of the AIT to provide multiple image magnifications, and several inspection NA values up to 0.35 NA equivalent (0.0875 mask-side). We report on the improved imaging capabilities including resolution below 100-nm on the mask side (25 nm, 4x wafer equivalent). EUV reticles are intricate optical systems made from of several materials with wavelength-specific optical properties. The combined interactions of the substrate, multilayer-stack, buffer layer and absorber layer produce a reflected EUV optical field that is challenging to model accurately, and difficult to fully assess without actinic at-wavelength inspection. Understanding the aerial image from lithographic printing alone is complicated by photoresist properties. The AIT is now used to investigate mask issues such as amplitude and phase defect printability, pattern repair techniques, contamination, inspection damage, and mask architecture. The AIT has a 6{sup o} illumination angle, and high-resolution exposure times are typically 20 seconds per image. The AIT operates semi-automatically capturing through-focus imaging series with step sizes as small as 0.1 {micro}m (0.5-0.8 {micro}m are typical), and …
Date: August 6, 2008
Creator: Goldberg, Kenneth A.; Mochi, Iacopo; Anderson, Erik H.; Rekawa, Seno B.; Kemp, Charles D.; Huh, S. et al.
Object Type: Article
System: The UNT Digital Library
Uncertainties in the Anti-neutrino Production at Nuclear Reactors (open access)

Uncertainties in the Anti-neutrino Production at Nuclear Reactors

Anti-neutrino emission rates from nuclear reactors are determined from thermal power measurements and fission rate calculations. The uncertainties in these quantities for commercial power plants and their impact on the calculated interaction rates in {bar {nu}}{sub e} detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties, and their relevance to reactor {bar {nu}}{sub e} experiments.
Date: August 6, 2008
Creator: Djurcic, Zelimir; Detwiler, Jason A.; Piepke, Andreas; Foster Jr., Vince R.; Miller, Lester & Gratta, Giorgio
Object Type: Article
System: The UNT Digital Library
Greensheet (Houston, Tex.), Vol. 39, No. 318, Ed. 1 Wednesday, August 6, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 318, Ed. 1 Wednesday, August 6, 2008

Free weekly newspaper that includes business and classified advertising.
Date: August 6, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Cherokeean Herald (Rusk, Tex.), Vol. 159, No. 24, Ed. 1 Wednesday, August 6, 2008 (open access)

Cherokeean Herald (Rusk, Tex.), Vol. 159, No. 24, Ed. 1 Wednesday, August 6, 2008

Weekly newspaper from Rusk, Texas that includes local, state and national news along with extensive advertising.
Date: August 6, 2008
Creator: Whitehead, Marie
Object Type: Newspaper
System: The Portal to Texas History
President of the United States: Compensation (open access)

President of the United States: Compensation

This report discusses the President’s compensation and the three most recent increases to the salary enacted in 1949 (81st Congress), 1969 (91st Congress), and 1999 (106th Congress).
Date: August 6, 2008
Creator: Schwemle, Barbara L.
Object Type: Report
System: The UNT Digital Library
The Greensheet (Dallas, Tex.), Vol. 32, No. 120, Ed. 1 Wednesday, August 6, 2008 (open access)

The Greensheet (Dallas, Tex.), Vol. 32, No. 120, Ed. 1 Wednesday, August 6, 2008

Free weekly newspaper that includes business and classified advertising.
Date: August 6, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 317, Ed. 1 Wednesday, August 6, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 317, Ed. 1 Wednesday, August 6, 2008

Free weekly newspaper that includes business and classified advertising.
Date: August 6, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Clifton Record (Clifton, Tex.), Vol. 113, No. 32, Ed. 1 Wednesday, August 6, 2008 (open access)

The Clifton Record (Clifton, Tex.), Vol. 113, No. 32, Ed. 1 Wednesday, August 6, 2008

Weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: Smith, W. Leon
Object Type: Newspaper
System: The Portal to Texas History
Central Asia: Regional Developments and Implications for U.S. Interests (open access)

Central Asia: Regional Developments and Implications for U.S. Interests

This report provides an overview of U.S. policy concerns and relations with countries in central Asia. The report discusses issues such as Fostering Pro-Western Orientations, Obstacles to Peace and Independence, Democratization and Human Rights, Security and Arms Control, Trade and Investment, and provides an Aid Overview.
Date: August 6, 2008
Creator: Nichol, Jim
Object Type: Report
System: The UNT Digital Library
Assistance to Firefighters Program: Distribution of Fire Grant Funding (open access)

Assistance to Firefighters Program: Distribution of Fire Grant Funding

This report discusses the inception of the Assistance to Firefighters Grant (AFG) program in the FY2001 National Defense Authorization Act, as well as current supplemental legislation and proposed funding.
Date: August 6, 2008
Creator: Kruger, Lennard G.
Object Type: Report
System: The UNT Digital Library
Libya: Background and U.S. Relations (open access)

Libya: Background and U.S. Relations

This report provides background information on Libya and U.S.-Libyan relations; profiles Libyan leader Muammar al Qadhafi; discusses Libya's political and economic reform efforts; and reviews current issues of potential congressional interest.
Date: August 6, 2008
Creator: Blanchard, Christopher M.
Object Type: Report
System: The UNT Digital Library
Nanotechnology and Environmental, Health, and Safety: Issues for Consideration (open access)

Nanotechnology and Environmental, Health, and Safety: Issues for Consideration

This report identifies the potential environmental, health, and safety opportunities and challenges of nanotechnology; explains the importance of addressing nanotechnology environmental, health, and safety (EHS) concerns; identifies and discusses nanotechnology EHS issues; and summarizes options for Congressional action, including the nanotechnology EHS-related provisions of selected legislation. The report also includes two appendices.
Date: August 6, 2008
Creator: Sargent, John F.
Object Type: Report
System: The UNT Digital Library
The Panola Watchman (Carthage, Tex.), Vol. 136, No. 63, Ed. 1 Wednesday, August 6, 2008 (open access)

The Panola Watchman (Carthage, Tex.), Vol. 136, No. 63, Ed. 1 Wednesday, August 6, 2008

Semiweekly newspaper from Carthage, Texas that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
The Baytown Sun (Baytown, Tex.), Vol. 88, No. 218, Ed. 1 Wednesday, August 6, 2008 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 88, No. 218, Ed. 1 Wednesday, August 6, 2008

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: Clements, Clifford E.
Object Type: Newspaper
System: The Portal to Texas History
The Animal Welfare Act: Background and Selected Legislation (open access)

The Animal Welfare Act: Background and Selected Legislation

This report describes the Background and Selected Legislation of The Animal Welfare Act which was first passed in 1966.
Date: August 6, 2008
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Speculation and Energy Prices: Legislative Responses (open access)

Speculation and Energy Prices: Legislative Responses

None
Date: August 6, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Colony Courier-Leader (The Colony, Tex.), Vol. 27, No. 27, Ed. 1 Wednesday, August 6, 2008 (open access)

The Colony Courier-Leader (The Colony, Tex.), Vol. 27, No. 27, Ed. 1 Wednesday, August 6, 2008

Weekly newspaper from The Colony, Texas that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: Monk, Devin
Object Type: Newspaper
System: The Portal to Texas History
The Altus Times (Altus, Okla.), Vol. 110, No. 5, Ed. 1 Wednesday, August 6, 2008 (open access)

The Altus Times (Altus, Okla.), Vol. 110, No. 5, Ed. 1 Wednesday, August 6, 2008

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Llano News (Llano, Tex.), Vol. 121, No. 45, Ed. 1 Wednesday, August 6, 2008 (open access)

The Llano News (Llano, Tex.), Vol. 121, No. 45, Ed. 1 Wednesday, August 6, 2008

Weekly newspaper from Llano, Texas that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: Stephenson, Jimmy
Object Type: Newspaper
System: The Portal to Texas History
Yoakum Herald-Times (Yoakum, Tex.), Vol. 116, No. 32, Ed. 1 Wednesday, August 6, 2008 (open access)

Yoakum Herald-Times (Yoakum, Tex.), Vol. 116, No. 32, Ed. 1 Wednesday, August 6, 2008

Weekly newspaper from Yoakum, Texas that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: McCracken, Michael S.
Object Type: Newspaper
System: The Portal to Texas History
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 93, No. 227, Ed. 1 Wednesday, August 6, 2008 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 93, No. 227, Ed. 1 Wednesday, August 6, 2008

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: August 6, 2008
Creator: Shance, Brenda
Object Type: Newspaper
System: The Gateway to Oklahoma History
U.S.-China Counterterrorism Cooperation: Issues for U.S. Policy (open access)

U.S.-China Counterterrorism Cooperation: Issues for U.S. Policy

This report discusses the United States counterterrorism cooperation with China after the terrorist attacks on September 11, 2001. This effort raised short-term policy issues about how to elicit cooperation and how to address China's concerns about military action (Operation Enduring Freedom). Longer-term questions have concerned whether counterterrorism has strategically transformed bilateral relations and whether China's support has been valuable and not obtained at the expense of other U.S. interests.
Date: August 6, 2008
Creator: Kan, Shirley A.
Object Type: Report
System: The UNT Digital Library