51 Matching Results

Results open in a new window/tab.

Advances in Low-Defect Multilayers for EUVL Mask Blanks (open access)

Advances in Low-Defect Multilayers for EUVL Mask Blanks

Low-defect multilayer coatings are required to fabricate mask blanks for Extreme Ultraviolet Lithography (EUVL). The mask blanks consist of high reflectance E W multilayers on low thermal expansion substrates. A defect density of 0.0025 printable defects/cm{sup 2} for both the mask substrate and the multilayer is required to provide a mask blank yield of 60%. Current low defect multilayer coating technology allows repeated coating-added defect levels of 0.05/cm{sup 2} for defects greater than 90 nm polystyrene latex sphere (PSL) equivalent size for lots of 20 substrates. Extended clean operation of the coating system at levels below 0.08/cm{sup 2} for 3 months of operation has also been achieved. Two substrates with zero added defects in the quality area have been fabricated, providing an existence proof that ultra low defect coatings are possible. Increasing the ion source-to-target distance from 410 to 560 mm to reduce undesired coating of the ion source caused the defect density to increase to 0.2/cm{sup 2}. Deposition and etching diagnostic witness substrates and deposition pinhole cameras showed a much higher level of ion beam spillover (ions missing the sputter target) than expected. Future work will quantify beam spillover, and test designs to reduce spillover, if it is confirmed …
Date: April 15, 2002
Creator: Folta, J. A.; Davidson, J. C.; Larson, C. C.; Walton, C. C. & Kearney, P. A.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 104, No. 26, Ed. 1 Monday, April 15, 2002 (open access)

Altus Times (Altus, Okla.), Vol. 104, No. 26, Ed. 1 Monday, April 15, 2002

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: April 15, 2002
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Alvin Sun (Alvin, Tex.), Vol. 111, No. 31, Ed. 1 Monday, April 15, 2002 (open access)

The Alvin Sun (Alvin, Tex.), Vol. 111, No. 31, Ed. 1 Monday, April 15, 2002

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: April 15, 2002
Creator: Schwind, Jim & Holton, Kathleen
Object Type: Newspaper
System: The Portal to Texas History
The Baytown Sun (Baytown, Tex.), Vol. 80, No. 140, Ed. 1 Monday, April 15, 2002 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 80, No. 140, Ed. 1 Monday, April 15, 2002

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: April 15, 2002
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS (open access)

BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

The principal objective of this project is to develop materials technology for use in ultrasupercritical (USC) plant boilers capable of operating with 760 C (1400 F), and up to 5500 psi with emphasis upon 35 MPa (5000 psi) steam. In the 21st century, the world faces the critical challenge of providing abundant, cheap electricity to meet the needs of a growing global population while at the same time preserving environmental values. Most studies of this issue conclude that a robust portfolio of generation technologies and fuels should be developed to assure that the United States will have adequate electricity supplies in a variety of possible future scenarios. The use of coal for electricity generation poses a unique set of challenges. On the one hand, coal is plentiful and available at low cost in much of the world, notably in the U.S., China, and India. Countries with large coal reserves will want to develop them to foster economic growth and energy security. On the other hand, traditional methods of coal combustion emit pollutants and CO{sub 2} at high levels relative to other generation options. Maintaining coal as a generation option in the 21st century will require methods for addressing these environmental …
Date: April 15, 2002
Creator: Viswanathan, R.
Object Type: Report
System: The UNT Digital Library
Clean Air Act Issues in the 107th Congress (open access)

Clean Air Act Issues in the 107th Congress

In the 107th Congress, the most prominent air quality issue has been whether state and federal regulations designed to protect air quality are having a negative impact on energy production, and, if so, whether legislation should be enacted to reform such regulations. The early discussion focused primarily on California, but with the release of the Administration’s energy policy recommendations in May 2001 and subsequent congressional action, attention shifted to issues more national in scope.
Date: April 15, 2002
Creator: McCarthy, James E.
Object Type: Report
System: The UNT Digital Library
Daily Journal (Perry, Okla.), Vol. 109, No. 75, Ed. 1 Monday, April 15, 2002 (open access)

Daily Journal (Perry, Okla.), Vol. 109, No. 75, Ed. 1 Monday, April 15, 2002

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: April 15, 2002
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
Design, operational experiences and beam results obtained with the SNS H- ion source and LEBT at Berkeley Lab (open access)

Design, operational experiences and beam results obtained with the SNS H- ion source and LEBT at Berkeley Lab

The ion source and Low-Energy Transport (LEBT) system that will provide H{sup -} ion beams to the Spallation Neutron Source (SNS)** Front End and the accelerator chain have been developed into a mature unit that fully satisfies the operational requirements through the commissioning and early operating phases of SNS. Compared to the early R&D version, many features of the ion source have been improved, and reliable operation at 6% duty factor has been achieved producing beam currents in the 35-mA range and above. LEBT operation proved that the purely electrostatic focusing principle is well suited to inject the ion beam into the RFQ accelerator, including the steering and pre-chopping functions. This paper will discuss the latest design features of the ion source and LEBT, give performance data for the integrated system, and report on commissioning results obtained with the SNS RFQ and Medium-Energy Beam Transport (MEBT) system. Prospects for further improvements will be outlined in concluding remarks.
Date: April 15, 2002
Creator: Keller, R.; Thomae, R.; Stockli, M. & Welton, R.
Object Type: Article
System: The UNT Digital Library
Disruption of NBS1 gene leads to early embryonic lethality in homozygous null mice and induces specific cancer in heterozygous mice (open access)

Disruption of NBS1 gene leads to early embryonic lethality in homozygous null mice and induces specific cancer in heterozygous mice

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive chromosome instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition, with cellular features similar to that of ataxia telangiectasia (AT). NBS results from mutations in the mammalian gene Nbs1 that codes for a 95-kDa protein called nibrin, NBS1, or p95. To establish an animal model for NBS, we attempted to generate NBS1 knockout mice. However, NBS1 gene knockouts were lethal at an early embryonic stage. NBS1 homozygous(-/-) blastocyst cells cultured in vitro showed retarded growth and subsequently underwent growth arrest within 5 days of culture. Apoptosis, assayed by TUNEL staining, was observed in NBSI homozygous(-/-) blastocyst cells cultured for four days. NBSI heterozygous(+/-) mice were normal, and exhibited no specific phenotype for at least one year. However, fibroblast cells from NBSI heterozygous(+/-) mice displayed an enhanced frequency of spontaneous transformation to anchorage-independent growth as compared to NBS1 wild-type(+/+) cells. Furthermore, heterozygous(+/-) mice exhibited a high incidence of hepatocellular carcinoma after one year compared to wild-type mice, even though no significant differences in the incidence of other tumors such as lung adenocarcinoma and lymphoma were observed. Taken together, these results strongly suggest that NBS1 heterozygosity and reduced NBSI expression induces …
Date: April 15, 2002
Creator: Kurimasa, Akihiro; Burma, Sandeep; Henrie, Melinda; Ouyang, Honghai; Osaki, Mitsuhiko; Ito, Hisao et al.
Object Type: Report
System: The UNT Digital Library
District of Columbia: Performance Report Reflects Progress and Opportunities for Improvement (open access)

District of Columbia: Performance Report Reflects Progress and Opportunities for Improvement

A letter report issued by the General Accounting Office with an abstract that begins "This report examines the progress the District of Columbia has made with its fiscal year 2001 performance accountability report and highlights continuing challenges facing our nation's capital. The District must submit a performance accountability plan with goals for the coming fiscal year and, at the end of the fiscal year, a performance accountability report on the extent to which it achieved these goals. GAO found that the District's Performance Accountability Report for Fiscal Year 2001 provided a more complete picture of its performance and made progress in complying with statutory reporting requirements by using a consistent set of goals. This allowed the District to measure and report progress toward the goals in its 2001 performance plan. Specifically, it reported information on the level of performance achieved, the titles of managers and their supervisors responsible for each goal, and described the status of certain court orders. The District has made progress over the last three years in its performance accountability reports and established positive direction for enhancements in court orders, its fiscal year 2003 performance based budgeting pilots, and performance goals and measures."
Date: April 15, 2002
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Documentation for FY2002 BTS GPRA Metrics (open access)

Documentation for FY2002 BTS GPRA Metrics

PNNL estimated the FY2002 energy, environmental, and financial benefits (i.e., metrics) of the technologies and practices in the U.S. Department of Energy's (DOE's) Office of Building Technology, State and Community Programs (BTS). BTS uses the estimates of benefits as part of its annual budget request. This report includes an overview of the analytical approaches used to estimate energy savings for the FY2002 appropriated budget for BTS. The report also includes descriptions of key assumptions and the methodology that is used to calculate energy savings estimates for each BTS program.
Date: April 15, 2002
Creator: Hostick, Donna J.; Belzer, David B.; Cort, Katherine A. & Dirks, James A.
Object Type: Report
System: The UNT Digital Library
Documentation for FY2003 BTS GPRA Metrics (open access)

Documentation for FY2003 BTS GPRA Metrics

PNNL estimated the FY2003 energy, environmental, and financial benefits (i.e., metrics) of the technologies and practices in the U.S. Department of Energy's (DOE's) Office of Building Technology, State and Community Programs (BTS). BTS uses the estimates of benefits as part of its annual budget request. This report includes an overview of the analytical approaches used to estimate energy savings for the FY2003 appropriated budget for BTS. The report also includes descriptions of key assumptions and the methodology that is used to calculate energy savings estimates for each BTS program.
Date: April 15, 2002
Creator: Hostick, Donna J.; Belzer, David B.; Cort, Katherine A.; Dirks, James A. & Pool, Rita H.
Object Type: Report
System: The UNT Digital Library
The effect of penetration factor, deposition, and environmental factors on the indoor concentration of PM2.5 sulfate, nitrate, and carbon (open access)

The effect of penetration factor, deposition, and environmental factors on the indoor concentration of PM2.5 sulfate, nitrate, and carbon

Indoor exposure to particles of outdoor origin constitutes an important exposure pathway. We conducted an intensive set of indoor particle measurements in an unoccupied house under differing operating conditions. Real-time measurements were conducted both indoors and outdoors, including PM2.5 nitrate, sulfate, and carbon. Because the time-scale of the fluctuations in outdoor particle concentrations and meteorological conditions are often similar to the time constant for building air exchange, a steady state concentration may never be reached. The time-series experimental data were used to determine the effect of changes in air exchange rate and indoor/outdoor temperature and relative humidity differences on indoor particle concentrations. A multivariate regression was performed to investigate the difference between measured indoor concentrations and results from a simple time-dependent physical model. Environmental conditions had a significant effect on indoor concentrations of all three PM2.5 species, but did not explain all of the model variation.
Date: April 15, 2002
Creator: Thatcher, T. L.; Lunden, M. M.; Sextro, R. G.; Hering, S. & Brown, N. J.
Object Type: Article
System: The UNT Digital Library
Electrical and optical properties of carbon-doped GaN grown by MBE on MOCVD GaN templates using a CCl4 dopant source (open access)

Electrical and optical properties of carbon-doped GaN grown by MBE on MOCVD GaN templates using a CCl4 dopant source

Carbon-doped GaN was grown by plasma-assisted molecular-beam epitaxy using carbon tetrachloride vapor as the dopant source. For moderate doping mainly acceptors were formed, yielding semi-insulating GaN. However at higher concentrations p-type conductivity was not observed, and heavily doped films (>5 x 10{sup 20} cm{sup -3}) were actually n-type rather than semi-insulating. Photoluminescence measurements showed two broad luminescence bands centered at 2.2 and 2.9 eV. The intensity of both bands increased with carbon content, but the 2.2 eV band dominated in n-type samples. Intense, narrow ({approx}6 meV) donor-bound exciton peaks were observed in the semi-insulating samples.
Date: April 15, 2002
Creator: Armitage, Rob; Yang, Qing; Feick, Henning; Park, Yeonjoon & Weber, Eicke R.
Object Type: Article
System: The UNT Digital Library
Employing Thin HPGe Detectors for Gamma-Ray Imaging (open access)

Employing Thin HPGe Detectors for Gamma-Ray Imaging

We have evaluated a collimator-less gamma-ray imaging system, which is based on thin layers of double-sided strip HPGe detectors. The position of individual gamma-ray interactions will be deduced by the strip addresses and the Ge layers which fired. Therefore, high bandwidth pulse processing is not required as in thick Ge detectors. While the drawback of such a device is the increased number of electronics channels to be read out and processed, there are several advantages, which are particularly important for remote applications: the operational voltage can be greatly reduced to fully deplete the detector and no high bandwidth signal processing electronics is required to determine positions. Only a charge sensitive preamplifier, a slow pulse shaping amplifier, and a fast discriminator are required on a per channel basis in order to determine photon energy and interaction position in three dimensions. Therefore, the power consumption and circuit board real estate can be minimized. More importantly, since the high bandwidth signal shapes are not used to determine the depth position, lower energy signals can be processed. The processing of these lower energy signals increases the efficiency for the recovery of small angle scattering. Currently, we are studying systems consisting of up to ten …
Date: April 15, 2002
Creator: Vetter, K; Mihailescu, L; Ziock, K; Burks, M; Hull, E; Madden, N et al.
Object Type: Article
System: The UNT Digital Library
ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION (open access)

ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION

This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO{sub 2} Mitigation project during the period from 1/3/2001 through 4/02/2002. Most of the achievements are milestones in our efforts to complete the tasks and subtasks that constitute the project objectives, and we are currently on schedule to complete Phase I activities by 10/2002, the milestone date from the original project timeline. As indicated in the list of accomplishments below, we are continuing to evaluate candidate organisms and growth surfaces, and we are expanding the test facilities in preparation for scaled up system-level testing. Specific results and accomplishments for the first quarter of 2002 include: Organisms and Growth Surfaces: (1) Isolate 1.2 s.c. (2) has been selected for further investigations because of its favorable growth properties. (2) Research on optimal conditions for the growth of cyanobacterial isolates from YNP should be carried out using distilled water which has more stable chemical parameters, although tap water use may be permissible during full scale operations (at the cost of longer organism doubling times). (3) Tr. 9.4 WF is able to generate a biofilm on an Omnisil surface. Over the long term Omnisil does not inhibit the growth of TR 9.4 isolate, …
Date: April 15, 2002
Creator: Kremer, Dr. Gregory; Bayless, David J.; Vis, Dr. Morgan; Prudich, Dr. Michael; Cooksey, Dr. Keith & Muhs, Dr. Jeff
Object Type: Report
System: The UNT Digital Library

Ensemble: 2002-04-15 – Collegium Musicum

Ensemble performance at the UNT College of Music Winspear Hall.
Date: April 15, 2002
Creator: University of North Texas. Collegium Musicum.
Object Type: Sound
System: The UNT Digital Library
Evaluation of Roof Bolting Requirements Based on In-Mine Bolter Drilling Progress Report (open access)

Evaluation of Roof Bolting Requirements Based on In-Mine Bolter Drilling Progress Report

Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal, potash, salt etc. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on such information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. More laboratory tests have been performed in this quarter. The analysis performed on the testing data showed: (1) abnormal rotational accelerations can be used as the indicator of the rock interfaces, and (2) the sharp drops of drilling thrust and torque agree well with the locations of fractures.
Date: April 15, 2002
Creator: Peng, Syd S.
Object Type: Report
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, April 15, 2002 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, April 15, 2002

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: April 15, 2002
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Fruits and Vegetables: Issues for Congress (open access)

Fruits and Vegetables: Issues for Congress

This report discusses the issues for Congress related to fruits & vegetables. The contents include federal activities, programs, farm bill issues, & trade issues.
Date: April 15, 2002
Creator: Branaman, Brenda
Object Type: Report
System: The UNT Digital Library
Fruits and Vegetables: Issues for Congress (open access)

Fruits and Vegetables: Issues for Congress

This report discusses the Issues for Congress on Fruits and Vegetables.The primary law that exclusively serves the produce industry is the perishable agriculture commodities act in the 1930(PACA).
Date: April 15, 2002
Creator: Branaman, Brenda
Object Type: Report
System: The UNT Digital Library
The Gayly Oklahoman (Oklahoma City, Okla.), Vol. 20, No. 8, Ed. 1 Monday, April 15, 2002 (open access)

The Gayly Oklahoman (Oklahoma City, Okla.), Vol. 20, No. 8, Ed. 1 Monday, April 15, 2002

Semi-monthly newspaper from Oklahoma City, Oklahoma that includes local, state, and national news and advertising of interest to the Lesbian, Gay, Bisexual, and Transgender (LGBT) community.
Date: April 15, 2002
Creator: Hawkins, Don
Object Type: Newspaper
System: The UNT Digital Library
Immigration Legislation and Status Adjustment Legislation (open access)

Immigration Legislation and Status Adjustment Legislation

None
Date: April 15, 2002
Creator: Wasem, Ruth Ellen
Object Type: Report
System: The UNT Digital Library
Independent Counsel or Special Prosecutor For the Enron Investigation (open access)

Independent Counsel or Special Prosecutor For the Enron Investigation

This report provides information on the special counsels and the department of justice regulations surrounding the allegations that the company Enron received favorable government treatment.
Date: April 15, 2002
Creator: Maskell, Jack
Object Type: Report
System: The UNT Digital Library