Month

40 Matching Results

Results open in a new window/tab.

TOF Electron Energy Analyzer for Spin and Angular Resolved Photoemission Spectroscopy (open access)

TOF Electron Energy Analyzer for Spin and Angular Resolved Photoemission Spectroscopy

Current pulsed laser and synchrotron x-ray sources provide new opportunities for Time-Of- Flight (TOF) based photoemission spectroscopy to increase photoelectron energy resolution and efficiency compared to current standard techniques. The principals of photoelectron timing front formation, temporal aberration minimization, and optimization of electron beam transmission are presented. We have developed these concepts into a high resolution Electron Optical Scheme (EOS) of a TOF Electron Energy Analyzer (TOF-EEA) for photoemission spectroscopy. The EOS of the analyzer includes an electrostatic objective lens, three columns of transport lenses and a 90 degree energy band pass filter (BPF). The analyzer has two modes of operation: Spectrometer Mode (SM) with straight passage of electrons through the EOS undeflected by the BPF, allowing the entire spectrum to be measured, and Monochromator Mode (MM) in which the BPF defines a certain energy window inside the scope of the electron energy spectrum.
Date: July 9, 2008
Creator: Lebedev, Gennadi; Jozwiak, Chris; Andresen, Nord; Lanzara, Alessandra & Hussain, Zahid
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF DETECTOR GRADE CDZNTE MATERIAL FROM REDLEN TECHNOLOGIES (open access)

CHARACTERIZATION OF DETECTOR GRADE CDZNTE MATERIAL FROM REDLEN TECHNOLOGIES

CdZnTe (or CZT) crystals can be used in a variety of detector-type applications. This large band gap material shows great promise for use as a gamma radiation spectrometer. Historically, the performance of CZT has typically been adversely affected by point defects, structural and compositional heterogeneities within the crystals, such as twinning, pipes, grain boundaries (polycrystallinity) and secondary phases (SP). The synthesis of CZT material has improved greatly with the primary performance limitation being attributed to mainly SP. In this presentation, we describe the extensive characterization of detector grade material that has been treated with post growth annealing to remove the SPs. Some of the analytical methods used in this study included polarized, cross polarized and transmission IR imaging, I-V curves measurements, synchrotron X-ray topography and electron microscopy.
Date: July 9, 2008
Creator: Duff, M
Object Type: Article
System: The UNT Digital Library
Scratch Forensics (open access)

Scratch Forensics

Scratches on optical components which are formed during fabrication, cleaning, handling and end-use, are widespread and almost always detrimental. The impact of scratches on the end-use of the optic includes increased optical scatter, reduced system performance, and reduced strength. In the case of optics used in high intensity laser applications, prevention of scratches is paramount because they are closely associated with laser damage. Evaluation of the characteristics (dimensions, location on optic, shape, and orientation) of a scratch can serve a powerful tool to identify the cause of the scratch and lead to mitigations to prevent their reoccurrence. It is likely that opticians have used such techniques for hundreds of years. In recent years, by applying techniques of fracture mechanics and tribology, several new semi-quantitative rules-of-thumb have been developed allowing one to estimate the size and shape of the scratch inducing asperity or rogue particle, the load on the particle, the depth of the fractures in the scratch, and properties of material housing the rogue particle. The following discussion reviews some these techniques, which as a whole, we refer to as 'Scratch Forsenics'.
Date: July 9, 2008
Creator: Suratwala, T I; Miller, P E; Feit, M D & Menapace, J A
Object Type: Article
System: The UNT Digital Library
Function-based Biosensor for Hazardous Waste Toxin Detection (open access)

Function-based Biosensor for Hazardous Waste Toxin Detection

There is a need for new types of toxicity sensors in the DOE and other agencies that are based on biological function as the toxins encountered during decontamination or waste remediation may be previously unknown or their effects subtle. Many times the contents of the environmental waste, especially the minor components, have not been fully identified and characterized. New sensors of this type could target unknown toxins that cause death as well as intermediate levels of toxicity that impair function or cause long term impairment that may eventually lead to death. The primary question posed in this grant was to create an electronically coupled neuronal cellular circuit to be used as sensor elements for a hybrid non-biological/biological toxin sensor system. A sensor based on the electrical signals transmitted between two mammalian neurons would allow the marriage of advances in solid state electronics with a functioning biological system to develop a new type of biosensor. Sensors of this type would be a unique addition to the field of sensor technology but would also be complementary to existing sensor technology that depends on knowledge of what is to be detected beforehand. We integrated physics, electronics, surface chemistry, biotechnology, and fundamental neuroscience in …
Date: July 9, 2008
Creator: Hickman, James J
Object Type: Report
System: The UNT Digital Library
Work Plan: Targeted Investigation to Assess Current Conditions Associated With the Carbon Tetrachloride Plume Downgradient From the Former CCC/Usda Facility at Milford, Nebraska. (open access)

Work Plan: Targeted Investigation to Assess Current Conditions Associated With the Carbon Tetrachloride Plume Downgradient From the Former CCC/Usda Facility at Milford, Nebraska.

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility at Milford, Nebraska. In May 2008, the CCC/USDA directed the Environmental Science Division of Argonne National Laboratory, as its technical consultant, to develop a work plan for a targeted investigation at the Milford site. The purpose of the targeted investigation is to assess the current extent and configuration of the carbon tetrachloride plume downgradient from the former CCC/USDA facility and proximal to the banks of the Big Blue River, which borders the area of concern to the east, southeast, and northeast. In 1995, carbon tetrachloride contamination was detected by the Nebraska Department of Health and Human Services in a private drinking water well and a livestock well 1.25 mi south of Milford (Figure 1.1). The Trojan drinking water well is located directly downgradient (approximately 300 ft east) of the former CCC/USDA facility. Low levels of carbon tetrachloride contamination were also found in the Troyer livestock well, approximately 1,200 ft north of the former CCC/USDA facility.
Date: July 9, 2008
Creator: LaFreniere, L. M.
Object Type: Report
System: The UNT Digital Library
Greensheet (Houston, Tex.), Vol. 39, No. 270, Ed. 1 Wednesday, July 9, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 270, Ed. 1 Wednesday, July 9, 2008

Free weekly newspaper that includes business and classified advertising.
Date: July 9, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Cherokeean Herald (Rusk, Tex.), Vol. 159, No. 20, Ed. 1 Wednesday, July 9, 2008 (open access)

Cherokeean Herald (Rusk, Tex.), Vol. 159, No. 20, Ed. 1 Wednesday, July 9, 2008

Weekly newspaper from Rusk, Texas that includes local, state and national news along with extensive advertising.
Date: July 9, 2008
Creator: Whitehead, Marie
Object Type: Newspaper
System: The Portal to Texas History
Texas Attorney General Opinion: GA-0643 (open access)

Texas Attorney General Opinion: GA-0643

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 the conduct of a constable implicates the resign-to-run provisions of article XVI, section 65 of the Texas Constitution (RQ-0665-GA)
Date: July 9, 2008
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: GA-0644 (open access)

Texas Attorney General Opinion: GA-0644

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, under section 70.001 of the Texas Property Code, an auto repair shop may assert a mechanic's lien for administrative and overheard charges when the shop does not repair the vehicle (RQ-0667-GA)
Date: July 9, 2008
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
The Greensheet (Dallas, Tex.), Vol. 32, No. 92, Ed. 1 Wednesday, July 9, 2008 (open access)

The Greensheet (Dallas, Tex.), Vol. 32, No. 92, Ed. 1 Wednesday, July 9, 2008

Free weekly newspaper that includes business and classified advertising.
Date: July 9, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Greensheet (Houston, Tex.), Vol. 39, No. 269, Ed. 1 Wednesday, July 9, 2008 (open access)

Greensheet (Houston, Tex.), Vol. 39, No. 269, Ed. 1 Wednesday, July 9, 2008

Free weekly newspaper that includes business and classified advertising.
Date: July 9, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Structural Consequences of Anionic Host-Cationic Guest Interactions in a Supramolecular Assembly (open access)

Structural Consequences of Anionic Host-Cationic Guest Interactions in a Supramolecular Assembly

The molecular structure of the self-assembled supramolecular assembly [M{sub 4}L{sub 6}]{sup 12-} has been explored with different metals (M = Ga{sup III}, Fe{sup III}, Ti{sup IV}) and different encapsulated guests (NEt{sub 4}{sup +}, BnNMe{sub 3}{sup +}, Cp{sub 2}Co{sup +}, Cp*{sub 2}Co{sup +}) by X-ray crystallography. While the identity of the metal ions at the vertices of the M{sub 4}L{sub 6} structure is found to have little effect on the assembly structure, encapsulated guests significantly distort the size and shape of the interior cavity of the assembly. Cations on the exterior of the assembly are found to interact with the assembly through either {pi}-{pi}, cation-{pi}, or CH-{pi} interactions. In some cases, the exterior guests interact with only one assembly, but cations with the ability to form multiple {pi}-{pi} interactions are able to interact with adjacent assemblies in the crystal lattice. The solvent accessible cavity of the assembly is modeled using the rolling probe method and found to range from 253-434 {angstrom}{sup 3}, depending on the encapsulated guest. Based on the volume of the guest and the volume of the cavity, the packing coefficient for each host-guest complex is found to range from 0.47-0.67.
Date: July 9, 2008
Creator: Pluth, Michael D.; Johnson, Darren W.; Szigethy, Geza; Davis, Anna V.; Teat, Simon J.; Oliver, Allen G. et al.
Object Type: Article
System: The UNT Digital Library
Wave, Tidal, and In-Stream Energy Projects: Which Federal Agency Has the Lead? (open access)

Wave, Tidal, and In-Stream Energy Projects: Which Federal Agency Has the Lead?

This report describes wave, tidal, and in-stream energy generation technologies -- also referred to as hydrokinetic or marine energy. It discusses the recent changes in law aimed to clarify the federal role in ocean wave and renewable energy.
Date: July 9, 2008
Creator: Lane, Nic
Object Type: Report
System: The UNT Digital Library
Issues Affecting Tidal, Wave, and In-Stream Generation Projects (open access)

Issues Affecting Tidal, Wave, and In-Stream Generation Projects

This report provides an overview of developments and considerations regarding wave, tidal, and in-stream energy generation technology. It summarizes federal involvement in the regulation of this new industry and highlights current issues in the field.
Date: July 9, 2008
Creator: Lane, Nic
Object Type: Report
System: The UNT Digital Library
The Clifton Record (Clifton, Tex.), Vol. 113, No. 28, Ed. 1 Wednesday, July 9, 2008 (open access)

The Clifton Record (Clifton, Tex.), Vol. 113, No. 28, Ed. 1 Wednesday, July 9, 2008

Weekly newspaper from Clifton, Texas that includes local, state, and national news along with advertising.
Date: July 9, 2008
Creator: Smith, W. Leon
Object Type: Newspaper
System: The Portal to Texas History
The Genetic Information Nondiscrimination Act of 2008 (GINA) (open access)

The Genetic Information Nondiscrimination Act of 2008 (GINA)

This report provides background on genetic information, legal implications regarding the use of this information, and relevant laws. It also discusses the statutory provisions of the Genetic Information Nondiscrimination Act of 2008 (GINA).
Date: July 9, 2008
Creator: Jones, Nancy Lee & Sarata, Amanda K.
Object Type: Report
System: The UNT Digital Library
Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments (open access)

Comprehensive Nuclear-Test-Ban Treaty: Background and Current Developments

This report discusses the history of implementing a nuclear test ban; the national positions on testing and the comprehensive nuclear-test-ban treaty (CTBT) and the treaty's negotiations and key provisions; and Congress's consideration of the Stockpile Stewardship Program, which seeks to maintain nuclear weapons without testing.
Date: July 9, 2008
Creator: Medalia, Jonathan
Object Type: Report
System: The UNT Digital Library
Public-Private Partnerships in Highway and Transit Infrastructure Provision (open access)

Public-Private Partnerships in Highway and Transit Infrastructure Provision

This report begins with a brief discussion of the surface transportation system and its financing needs as background to the debate on public-private partnerships (PPPs). That is followed by sections describing the different types of PPPs, with details of a few prominent examples, and the development of federal legislation with respect to PPPs. The report then discusses the main issues of contention with the construction and longterm leasing of highways by the private sector, particularly as they relate to the funding, planning, and operation of the surface transportation system, before providing some policy options Congress may wish to consider.
Date: July 9, 2008
Creator: Mallett, William J.
Object Type: Report
System: The UNT Digital Library
Molten Salt Heat Transport Loop: Materials Corrosion and Heat Transfer Phenomena. Final Report (open access)

Molten Salt Heat Transport Loop: Materials Corrosion and Heat Transfer Phenomena. Final Report

An experimental system for corrosion testing of candidate materials in molten FLiNaK salt at 850 degree C has been designed and constructed. While molten FLiNaK salt was the focus of this study, the system can be utilized for evaluation of materials in other molten salts that may be of interest in the future. Using this system, the corrosion performance of a number of code-certified alloys of interest to NGNP as well as the efficacy of Ni-electroplating have been investigated. The mechanisums underlying corrosion processes have been elucidated using scanning electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy of the materials after the corrosion tests, as well as by the post-corrosion analysis of the salts using inductively coupled plasma (ICP) and neutron activation analysis (NAA) techniques.
Date: July 9, 2008
Creator: Sridharan, Kumar; Anderson, Mark; Corradini, Michael; Allen, Todd; Olson, Luke; Ambrosek, James et al.
Object Type: Report
System: The UNT Digital Library
The Panola Watchman (Carthage, Tex.), Vol. 136, No. 55, Ed. 1 Wednesday, July 9, 2008 (open access)

The Panola Watchman (Carthage, Tex.), Vol. 136, No. 55, Ed. 1 Wednesday, July 9, 2008

Semiweekly newspaper from Carthage, Texas that includes local, state, and national news along with advertising.
Date: July 9, 2008
Creator: unknown
Object Type: Newspaper
System: The Portal to Texas History
Expanding the Scope of the Public Performance Right for Sound Recordings: A Legal Analysis of the Performance Rights Act of 2007 (H.R. 4789 and S. 2500) (open access)
The Colony Courier-Leader (The Colony, Tex.), Vol. 27, No. 23, Ed. 1 Wednesday, July 9, 2008 (open access)

The Colony Courier-Leader (The Colony, Tex.), Vol. 27, No. 23, Ed. 1 Wednesday, July 9, 2008

Weekly newspaper from The Colony, Texas that includes local, state, and national news along with advertising.
Date: July 9, 2008
Creator: Monk, Devin
Object Type: Newspaper
System: The Portal to Texas History
[National Stonewall Democrats Chapter Email] (open access)

[National Stonewall Democrats Chapter Email]

A brief email from Daniel Graney to Al Daniels on July 9, 2008 that contains a link to the Stonewall Democrats website.
Date: July 9, 2008
Creator: unknown
Object Type: Text
System: The UNT Digital Library
The Altus Times (Altus, Okla.), Vol. 109, No. 345, Ed. 1 Wednesday, July 9, 2008 (open access)

The Altus Times (Altus, Okla.), Vol. 109, No. 345, Ed. 1 Wednesday, July 9, 2008

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: July 9, 2008
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History