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High efficiency, radiation-hard solar cells (open access)

High efficiency, radiation-hard solar cells

The direct gap of the In{sub 1-x}Ga{sub x}N alloy system extends continuously from InN (0.7 eV, in the near IR) to GaN (3.4 eV, in the mid-ultraviolet). This opens the intriguing possibility of using this single ternary alloy system in single or multi-junction (MJ) solar cells of the type used for space-based surveillance satellites. To evaluate the suitability of In{sub 1-x}Ga{sub x}N as a material for space applications, high quality thin films were grown with molecular beam epitaxy and extensive damage testing with electron, proton, and alpha particle radiation was performed. Using the room temperature photoluminescence intensity as a indirect measure of minority carrier lifetime, it is shown that In{sub 1-x}Ga{sub x}N retains its optoelectronic properties at radiation damage doses at least 2 orders of magnitude higher than the damage thresholds of the materials (GaAs and GaInP) currently used in high efficiency MJ cells. This indicates that the In{sub 1-x}Ga{sub x}N is well-suited for the future development of ultra radiation-hard optoelectronics. Critical issues affecting development of solar cells using this material system were addressed. The presence of an electron-rich surface layer in InN and In{sub 1-x}Ga{sub x}N (0 < x < 0.63) was investigated; it was shown that this is …
Date: October 22, 2004
Creator: Ager, J. W., III & Walukiewicz, W.
Object Type: Report
System: The UNT Digital Library
Development of a Novel Catalyst for NO Decomposition (open access)

Development of a Novel Catalyst for NO Decomposition

Air pollution arising from the emission of nitrogen oxides as a result of combustion taking place in boilers, furnaces and engines, has increasingly been recognized as a problem. New methods to remove NO{sub x} emissions significantly and economically must be developed. The current technology for post-combustion removal of NO is the selective catalytic reduction (SCR) of NO by ammonia or possibly by a hydrocarbon such as methane. The catalytic decomposition of NO to give N{sub 2} will be preferable to the SCR process because it will eliminate the costs and operating problems associated with the use of an external reducing species. The most promising decomposition catalysts are transition metal (especially copper)-exchanged zeolites, perovskites, and noble metals supported on metal oxides such as alumina, silica, and ceria. The main shortcoming of the noble metal reducible oxide (NMRO) catalysts is that they are prone to deactivation by oxygen. It has been reported that catalysts containing tin oxide show oxygen adsorption behavior that may involve hydroxyl groups attached to the tin oxide. This is different than that observed with other noble metal-metal oxide combinations, which have the oxygen adsorbing on the noble metal and subsequently spilling over to the metal oxide. This observation …
Date: October 22, 2004
Creator: Akyurtlu, Ates & Akyurtlu, Jale F.
Object Type: Report
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 106, No. 175, Ed. 1 Friday, October 22, 2004 (open access)

Altus Times (Altus, Okla.), Vol. 106, No. 175, Ed. 1 Friday, October 22, 2004

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Andrews, Mike
Object Type: Newspaper
System: The Gateway to Oklahoma History
Report of the Solar and Atmospheric Neutrino Working Group (open access)

Report of the Solar and Atmospheric Neutrino Working Group

The highest priority of the Solar and Atmospheric Neutrino Experiment Working Group is the development of a real-time, precision experiment that measures the pp solar neutrino flux. A measurement of the pp solar neutrino flux, in comparison with the existing precision measurements of the high energy {sup 8}B neutrino flux, will demonstrate the transition between vacuum and matter-dominated oscillations, thereby quantitatively testing a fundamental prediction of the standard scenario of neutrino flavor transformation. The initial solar neutrino beam is pure {nu}{sub e}, which also permits sensitive tests for sterile neutrinos. The pp experiment will also permit a significantly improved determination of {theta}{sub 12} and, together with other solar neutrino measurements, either a measurement of {theta}{sub 13} or a constraint a factor of two lower than existing bounds. In combination with the essential pre-requisite experiments that will measure the {sup 7}Be solar neutrino flux with a precision of 5%, a measurement of the pp solar neutrino flux will constitute a sensitive test for non-standard energy generation mechanisms within the Sun. The Standard Solar Model predicts that the pp and {sup 7}Be neutrinos together constitute more than 98% of the solar neutrino flux. The comparison of the solar luminosity measured via neutrinos …
Date: October 22, 2004
Creator: Back, H.; Bahcall, J. N.; Bernabeu, J.; Boulay, M. G.; Bowles, T.; Calaprice, F. et al.
Object Type: Report
System: The UNT Digital Library
Assistance After Hurricanes and Other Disasters: FY2004 and FY2005 Supplemental Appropriations (open access)

Assistance After Hurricanes and Other Disasters: FY2004 and FY2005 Supplemental Appropriations

After a series of devastating hurricanes struck Florida and other states in the summer of 2004, the 108th Congress passed two emergency supplemental appropriations statutes that provide a total of $16.475 billion to areas stricken by the hurricanes and other natural disasters. The House and Senate quickly approved legislation (H.R. 5005) the day after President Bush submitted a request on September 6 for $2 billion in FY2004 funding, largely in response to the devastation caused by Hurricanes Charley and Frances in Florida. The other issue that was a matter of public debate focused on a proposed amendment in the House to fully offset the cost of the FY2005 supplemental through a proportional reduction in discretionary funds; the House rejected the amendment.
Date: October 22, 2004
Creator: Bea, Keith & Chite, Ralph M.
Object Type: Report
System: The UNT Digital Library
Military Medical Care Services: Questions and Answers (open access)

Military Medical Care Services: Questions and Answers

None
Date: October 22, 2004
Creator: Best, Richard A., Jr.
Object Type: Report
System: The UNT Digital Library
Committee of the Whole: Stages of Action on Measures (open access)

Committee of the Whole: Stages of Action on Measures

This report provides information about the Stages of Action on Measures on Committee of the Whole.
Date: October 22, 2004
Creator: Beth, Richard S.
Object Type: Report
System: The UNT Digital Library
How Special Rules Regulate Calling up Measures for Consideration in the House (open access)

How Special Rules Regulate Calling up Measures for Consideration in the House

This report provides an overview of how special rules regulate calling up measures for consideration in the House.
Date: October 22, 2004
Creator: Beth, Richard S.
Object Type: Report
System: The UNT Digital Library
Homeland Security: Protecting Airliners from Terrorist Missiles (open access)

Homeland Security: Protecting Airliners from Terrorist Missiles

This report describes protecting Airliners from Terrorist Missiles related to Homeland Security.
Date: October 22, 2004
Creator: Bolkcom, Christopher; Feickert, Andrew & Elias, Bartholomew
Object Type: Report
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 90, No. 34, Ed. 1 Friday, October 22, 2004 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 90, No. 34, Ed. 1 Friday, October 22, 2004

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Broaddus, Matthew B.
Object Type: Newspaper
System: The Gateway to Oklahoma History
Perry Daily Journal (Perry, Okla.), Vol. 111, No. 203, Ed. 1 Friday, October 22, 2004 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 111, No. 203, Ed. 1 Friday, October 22, 2004

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Express-Star (Chickasha, Okla.), Ed. 1 Friday, October 22, 2004 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Friday, October 22, 2004

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Senate Committee Reports: Required Contents (open access)

Senate Committee Reports: Required Contents

This report briefly describes Senate rules and statutes that specify information that must be included as part of the written report about the purposes and provisions of a proposed measure. Senate committees also may include additional items in their reports.
Date: October 22, 2004
Creator: Carr, Thomas P.
Object Type: Report
System: The UNT Digital Library
Boerne Star & Hill Country Recorder (Boerne, Tex.), Vol. 98, No. 73, Ed. 1 Friday, October 22, 2004 (open access)

Boerne Star & Hill Country Recorder (Boerne, Tex.), Vol. 98, No. 73, Ed. 1 Friday, October 22, 2004

Semiweekly newspaper from Boerne, Texas that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Cartwright, Brian & Barboza, Kerry
Object Type: Newspaper
System: The Portal to Texas History
The Baytown Sun (Baytown, Tex.), Vol. 83, No. 323, Ed. 1 Friday, October 22, 2004 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 83, No. 323, Ed. 1 Friday, October 22, 2004

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
The Message, Volume 40, Number 5, October 2004 (open access)

The Message, Volume 40, Number 5, October 2004

Newsletter of Congregation Beth Yeshurun in Houston, including news and events, upcoming services, member announcements, editorials, and other information of interest to congregants.
Date: October 22, 2004
Creator: Congregation Beth Yeshurun (Houston, Tex.)
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Supersonic Propagation of Ionization Waves in an Under-Dense, Laser-Produced Plasma (open access)

Supersonic Propagation of Ionization Waves in an Under-Dense, Laser-Produced Plasma

We observe a laser-driven supersonic ionization wave heating a mm-scale plasma of sub-critical density up to 2-3 keV electron temperatures. Propagation velocities initially 10 times the sound speed were measured by means of time-resolved x-ray imaging diagnostics. The measured ionization wave trajectory is modeled analytically and by a 2D radiation-hydrodynamics code. The comparison to the modeling suggests that nonlocal heat transport effects may contribute to the attenuation of the heat wave propagation.
Date: October 22, 2004
Creator: Constantin, C.; Back, C. A.; Fournier, K. B.; Gregori, G.; Landen, O. L.; Glenzer, S. H. et al.
Object Type: Article
System: The UNT Digital Library
Sudan: The Darfur Crisis and the Status of the North-South Negotiations (open access)

Sudan: The Darfur Crisis and the Status of the North-South Negotiations

None
Date: October 22, 2004
Creator: Dagne, Theodore S. & Everett, Bathsheaba
Object Type: Report
System: The UNT Digital Library
The Rice Thresher, Vol. 92, No. 9, Ed. 1 Friday, October 22, 2004 (open access)

The Rice Thresher, Vol. 92, No. 9, Ed. 1 Friday, October 22, 2004

A weekly student newspaper from the Rice University in Houston, Texas that includes campus news and commentaries along with advertising.
Date: October 22, 2004
Creator: Gilbert, Lindsey & Yardley, Jonathan
Object Type: Newspaper
System: The Portal to Texas History
The Sealy News (Sealy, Tex.), Vol. 117, No. 85, Ed. 1 Friday, October 22, 2004 (open access)

The Sealy News (Sealy, Tex.), Vol. 117, No. 85, Ed. 1 Friday, October 22, 2004

Semiweekly newspaper from Sealy, Texas that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Griffin, Joanie & Horecka, Bobby
Object Type: Newspaper
System: The Portal to Texas History
Civilian Nuclear Waste Disposal (open access)

Civilian Nuclear Waste Disposal

This report mainly provides information about the Civilian Nuclear Waste Disposal.Federal policy is based on the premise that nuclear waste can be disposed of safety.
Date: October 22, 2004
Creator: Holt, Mark
Object Type: Report
System: The UNT Digital Library
THERMAL CONDUCTIVITY OF NON-REPOSITORY LITHOSTRATIGRAPHIC LAYERS (open access)

THERMAL CONDUCTIVITY OF NON-REPOSITORY LITHOSTRATIGRAPHIC LAYERS

This model report addresses activities described in ''Technical Work Plan for: Near-Field Environment and Transport Thermal Properties and Analysis Reports Integration'' (BSC 2004 [DIRS 171708]). The model develops values for thermal conductivity, and its uncertainty, for the nonrepository layers of Yucca Mountain; in addition, the model provides estimates for matrix porosity and dry bulk density for the nonrepository layers. The studied lithostratigraphic units, as identified in the ''Geologic Framework Model'' (GFM 2000) (BSC 2004 [DIRS 170029]), are the Timber Mountain Group, the Tiva Canyon Tuff, the Yucca Mountain Tuff, the Pah Canyon Tuff, the Topopah Spring Tuff (excluding the repository layers), the Calico Hills Formation, the Prow Pass Tuff, the Bullfrog Tuff, and the Tram Tuff. The deepest model units of the GFM (Tund and Paleozoic) are excluded from this study because no data suitable for model input are available. The parameter estimates developed in this report are used as input to various models and calculations that simulate heat transport through the rock mass. Specifically, analysis model reports that use product output from this report are: (1) Drift-scale coupled processes (DST and TH seepage) models; (2) Drift degradation analysis; (3) Multiscale thermohydrologic model; and (4) Ventilation model and analysis report. …
Date: October 22, 2004
Creator: JONES, R.
Object Type: Report
System: The UNT Digital Library
Iraq: U.S. Regime Change Efforts and Post-Saddam Governance (open access)

Iraq: U.S. Regime Change Efforts and Post-Saddam Governance

Operation Iraqi Freedom accomplished a long-standing U.S. objective, the overthrow of Saddam Hussein, but replacing his regime with a stable, moderate, democratic political structure has run into significant difficulty. That outcome would contribute to preventing Iraq from becoming a sanctuary for terrorists, a key recommendation of the September 11 Commission report (Chapter 12, Section 2). During the 1990s, U.S. efforts to change the regime covertly failed because of limited U.S. commitment, disorganization of the Iraqi opposition, and the vigilance of Iraq’s several overlapping security services. Previous U.S. Administrations had ruled out a U.S. military invasion to change the regime, believing such action would be risky and that Iraq did not necessarily pose a level of threat that would justify doing so. President George W. Bush characterized Iraq as a grave potential threat to the United States because of its refusal to abandon its weapons of mass destruction (WMD) programs and its potential to transfer WMD to terrorist groups. After a November 2002-March 2003 round of U.N. WMD inspections in which Iraq’s cooperation was mixed, on March 19, 2003, the United States launched Operation Iraqi Freedom to disarm Iraq and change its regime. The regime fell on April 9, 2003.
Date: October 22, 2004
Creator: Katzman, Kenneth
Object Type: Report
System: The UNT Digital Library
Hudspeth County Herald and Dell Valley Review (Dell City, Tex.), Vol. 49, No. 60, Ed. 1 Friday, October 22, 2004 (open access)

Hudspeth County Herald and Dell Valley Review (Dell City, Tex.), Vol. 49, No. 60, Ed. 1 Friday, October 22, 2004

Weekly newspaper from Dell City, Texas that includes local, state, and national news along with advertising.
Date: October 22, 2004
Creator: Lynch, Mary Louise
Object Type: Newspaper
System: The Portal to Texas History