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An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles (open access)

An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles

An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.
Date: September 12, 2000
Creator: Cunningham, C.T. & Roberts, R.S.
Object Type: Article
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 101, No. 157, Ed. 1 Tuesday, September 12, 2000 (open access)

Altus Times (Altus, Okla.), Vol. 101, No. 157, Ed. 1 Tuesday, September 12, 2000

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: September 12, 2000
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
Analysis of ultrafine TATB by ultrasonic-assisted equilibrium headspace analysis (open access)

Analysis of ultrafine TATB by ultrasonic-assisted equilibrium headspace analysis

The purpose of this work was to screen different lots of ultrafine 1,3,5-triamine 2,4,6-trinitrobenzene (TATB) for chemical differences, which may include synthesis and formulation byproducts, decomposition products, and contaminants. The approach used here permits analysis of trapped species as volatile and semivolatile chemicals within a solid. This procedure involves preconcentration of species from the TATB matrix into a surrounding headspace followed by a preconcentration and collection step using solid phase microextraction (SPME) collection. The sample is prepared by sealing it in a glass ampule with a few milliliters of water, ultrasonicating the solution, and then sampling the headspace using SPME collection. Water couples in the ultrasonic energy to fracture the TATB, which permits the release of nonpolar species into the gas phase. However, polar species will favor the aqueous phase and require a separate analysis procedure, which is not included here. Following SPME collection, the sample is transferred to a gas chromatography/mass spectrometer (GCMS) for analysis. In this work, we analyzed and interpreted outgas signatures from four different lots (1169-135MPS-001, 4271-135M-002, 91190-135M-003, and 98170-135M-001) of ultrafine TATB. Lot 98170-135M-001 is a reprocessing of Lot 4271-135M-002, which was washed to remove the water-soluble polysaccharides. The pedigree for these materials are found …
Date: September 12, 2000
Creator: Chambers, D M
Object Type: Report
System: The UNT Digital Library
Army Corps of Engineers: An Assessment of the Lower Snake River Dams' Draft Environmental Impact Statement (open access)

Army Corps of Engineers: An Assessment of the Lower Snake River Dams' Draft Environmental Impact Statement

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed its assessment of the Army Corps of Engineers' draft Environmental Impact Statement (EIS) for the Lower Snake River dams, focusing on whether the Corps: (1) followed applicable procedures and guidelines in preparing the draft EIS; and (2) used a reasonable methodology to analyze and present the effects of breaching, specifically with respect to electricity costs, transportation costs, and air quality."
Date: September 12, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Atomic Structure and Deformation Behavior of Bulk Amorphous Alloys (open access)

Atomic Structure and Deformation Behavior of Bulk Amorphous Alloys

The objective of this project was to gain a basic understanding of the atomic and defect structure of BAAs and of how structural stability affects their deformation behavior. We placed particular emphasis on understanding (1) shear-band formation, which is the dominant deformation mode at ambient temperature; and (2) Newtonian plastic flow, which is expected to be the dominant deformation mode at supercooled-liquid temperatures in BAAs. Such understandings would allow suppression of shear instability, promotion of homogeneous deformation at low temperatures, and improved formability at supercooled-liquid temperatures.
Date: September 12, 2000
Creator: Nieh, T. G.; Hsiung, L. M. & Choi, B. W.
Object Type: Report
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 78, No. 291, Ed. 1 Tuesday, September 12, 2000 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 78, No. 291, Ed. 1 Tuesday, September 12, 2000

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: September 12, 2000
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
Beam collimation system for a 16 GeV proton driver (open access)

Beam collimation system for a 16 GeV proton driver

It is shown that with the appropriate lattice and collimation design, one can control beam loss in the 16 GeV Fermilab Proton Driver. Based on detailed Monte-Carlo simulations, a 3-stage collimation system is proposed which consists of primary, secondary and supplementary collimators located in a special 60 m long injection section along with a painting system. It allows localization of more than 99% of beam loss to this section with only a 0.3 W/m (on average) beam loss rate in the rest of the machine. As a result, beam loss and induced radiation effects in lattice elements can be reduced to levels which are defined as acceptable.
Date: September 12, 2000
Creator: Alexandr I. Drozhdin, Carol J. Johnstone and Nikolai V. Mokhov
Object Type: Article
System: The UNT Digital Library
The Boerne Star (Boerne, Tex.), Vol. 95, No. 73, Ed. 1 Tuesday, September 12, 2000 (open access)

The Boerne Star (Boerne, Tex.), Vol. 95, No. 73, Ed. 1 Tuesday, September 12, 2000

Semiweekly newspaper from Boerne, Texas that includes local, state, and national news along with advertising.
Date: September 12, 2000
Creator: Keasling, Edna & Fierro, Jennifer
Object Type: Newspaper
System: The Portal to Texas History
Brady Standard-Herald and Heart O' Texas News (Brady, Tex.), Ed. 1 Tuesday, September 12, 2000 (open access)

Brady Standard-Herald and Heart O' Texas News (Brady, Tex.), Ed. 1 Tuesday, September 12, 2000

Semiweekly newspaper from Brady, Texas that includes local, state, and national news along with advertising.
Date: September 12, 2000
Creator: Stewart, James E.
Object Type: Newspaper
System: The Portal to Texas History
The Case of Elian Gonzalez: Legal Basics (open access)

The Case of Elian Gonzalez: Legal Basics

None
Date: September 12, 2000
Creator: Eig, Larry M.
Object Type: Report
System: The UNT Digital Library
Characterization of the Dilute Ising Antiferromagnet (open access)

Characterization of the Dilute Ising Antiferromagnet

A spin glass is a magnetic ground state in which ferromagnetic and antiferromagnetic exchange interactions compete, thereby creating frustration and a multidegenerate state with no long range order. An Ising system is a system where the spins are constrained to lie parallel or antiparallel to a primary axis. There has been much theoretical interest in the past ten years in the effects of applying a magnetic field transverse to the primary axis in an Ising spin glass at low temperatures and thus study phase transitions at the T=0 limit. The focus of this study is to search for and characterize a new Ising spin glass system. This is accomplished by site diluting yttrium for terbium in the crystalline material TbNi{sub 2}Ge{sub 2}. The first part of this work gives a brief overview of the physics of rare earth magnetism and an overview of experimental characteristics of spin glasses. This is followed by the methodology used to manufacture the large single crystals used in this study, as well as the measurement techniques used. Next, a summary of the results of magnetic measurements on across the dilution series from pure terbium to pure yttrium is presented. This is followed by detailed measurements …
Date: September 12, 2000
Creator: Wiener, T.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Charter Schools: Limited Access to Facility Financing (open access)

Charter Schools: Limited Access to Facility Financing

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the financing of facilities for charter schools, focusing on: (1) the degree to which charter schools have access to traditional public school facility financing; (2) whether alternative sources of facility financing are available to charter schools; and (3) potential options generally available to the federal government if it were to assume a larger role in character school facility financing."
Date: September 12, 2000
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
CP violation and B mixing in CDF-II (open access)

CP violation and B mixing in CDF-II

In March 2001, the Tevatron at Fermilab will start a new run at {radical}s = 2.0 TeV, delivering an integrated luminosity of 2 fb{sup {minus}1} in the first two years and more than 15 fb{sup {minus}1} in the following years, before the start of LHC at CERN. CDF has been upgraded to cope with the new physics program. The authors present here the prospects for measuring B mixing and CP violation during the upcoming run.
Date: September 12, 2000
Creator: Ruiz, Alberto
Object Type: Article
System: The UNT Digital Library
Critical Infrastructures: Background and Early Implementation of PDD-63 (open access)

Critical Infrastructures: Background and Early Implementation of PDD-63

The nation's health, wealth, and security rely on the supply and distribution of certain goods and services. The array of physical assets, processes and organizations across which these goods and services move are called critical infrastructures (e.g. electricity, the power plants that generate it, and the electric grid upon which it is distributed or financial capital, the institutions that manage it, and the record- keeping and communications that move it from one institution to another).
Date: September 12, 2000
Creator: Moteff, John D.
Object Type: Report
System: The UNT Digital Library
Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry (open access)

Development and Evaluation of an Externally Air-Cooled Low-Flow torch and the Attenuation of Space Charge and Matrix Effects in Inductively Coupled Plasma Mass Spectrometry

An externally air-cooled low-flow torch has been constructed and successfully demonstrated for applications in inductively coupled plasma mass spectrometry (ICP-MS). The torch is cooled by pressurized air flowing at {approximately}70 L/min through a quartz air jacket onto the exterior of the outer tube. The outer gas flow rate and operating RF forward power are reduced considerably. Although plasmas can be sustained at the operating power as low as 400 W with a 2 L/min of outer gas flow, somewhat higher power and outer gas flows are advisable. A stable and analytical useful plasma can be obtained at 850 W with an outer gas flow rate of {approximately}4 L/min. Under these conditions, the air-cooled plasma produces comparable sensitivities, doubly charged ion ratios, matrix effects and other analytical merits as those produced by a conventional torch while using significantly less argon and power requirements. Metal oxide ion ratios are slightly higher with the air-cooled plasma but can be mitigated by reducing the aerosol gas flow rate slightly with only minor sacrifice in analyte sensitivity. A methodology to alleviate the space charge and matrix effects in ICP-MS has been developed. A supplemental electron source adapted from a conventional electron impact ionizer is added …
Date: September 12, 2000
Creator: Praphairaksit, N.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Development of a method for monitoring the consistency of glass-bonded sodalite waste forms. (open access)

Development of a method for monitoring the consistency of glass-bonded sodalite waste forms.

None
Date: September 12, 2000
Creator: Lewis, M. A.; Stanley, M. L. & Ebert, W. L.
Object Type: Report
System: The UNT Digital Library
Diffractive physics at the Tevatron (open access)

Diffractive physics at the Tevatron

Experimental results of hard single diffraction and double pomeron exchange studies at the Fermilab Tevatron p{bar p} collider are presented. Single diffraction results are compared with predictions from phenomenological models and expectations from results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA. Double pomeron exchange results are compared with corresponding single diffraction results to test factorization.
Date: September 12, 2000
Creator: Hatakeyama, K.
Object Type: Article
System: The UNT Digital Library
Disposal of Surplus Weapons Grade Plutonium (open access)

Disposal of Surplus Weapons Grade Plutonium

The Office of Fissile Materials Disposition is responsible for disposing of inventories of surplus US weapons-usable plutonium and highly enriched uranium as well as providing, technical support for, and ultimate implementation of, efforts to obtain reciprocal disposition of surplus Russian plutonium. On January 4, 2000, the Department of Energy issued a Record of Decision to dispose of up to 50 metric tons of surplus weapons-grade plutonium using two methods. Up to 17 metric tons of surplus plutonium will be immobilized in a ceramic form, placed in cans and embedded in large canisters containing high-level vitrified waste for ultimate disposal in a geologic repository. Approximately 33 metric tons of surplus plutonium will be used to fabricate MOX fuel (mixed oxide fuel, having less than 5% plutonium-239 as the primary fissile material in a uranium-235 carrier matrix). The MOX fuel will be used to produce electricity in existing domestic commercial nuclear reactors. This paper reports the major waste-package-related, long-term disposal impacts of the two waste forms that would be used to accomplish this mission. Particular emphasis is placed on the possibility of criticality. These results are taken from a summary report published earlier this year.
Date: September 12, 2000
Creator: Alsaed, H. & Gottlieb, P.
Object Type: Report
System: The UNT Digital Library
Electrostatic Discharge/Electrical Overstress Susceptibility in MEMS: A New Failure Mode (open access)

Electrostatic Discharge/Electrical Overstress Susceptibility in MEMS: A New Failure Mode

None
Date: September 12, 2000
Creator: Walraven, Jeremy A.; Soden, Jerry M.; Tanner, Danelle M.; Tangyunyong, Paiboon; Cole, Edward I., Jr.; Anderson, Richard E. et al.
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, September 12, 2000 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, September 12, 2000

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: September 12, 2000
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Failure Analysis of MEMS Using Thermally-Induced Voltage Alteration (open access)

Failure Analysis of MEMS Using Thermally-Induced Voltage Alteration

None
Date: September 12, 2000
Creator: Walraven, Jeremy A.; Cole, Edward I., Jr. & Tangyunyong, Paiboon
Object Type: Article
System: The UNT Digital Library
Federal Chief Information Officer: Leadership Needed to Confront Serious Challenges and Emerging Issues (open access)

Federal Chief Information Officer: Leadership Needed to Confront Serious Challenges and Emerging Issues

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the creation of a federal chief information officer (CIO), focusing on the: (1) structure and responsibilities of existing state and foreign governmentwide CIO models; (2) federal CIO approaches proposed by two bills; and (3) type of leadership responsibilities that a federal CIO should possess."
Date: September 12, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Gas Generation from K East Basin Sludges - Series I Testing (open access)

Gas Generation from K East Basin Sludges - Series I Testing

This report describes work to examine the gas generation behavior of actual K East (KE) Basin floor and canister sludge. The path forward for management of the K Basin Sludge is to retrieve, ship, and store the sludge at T Plant until final processing at some future date. Gas generation will impact the designs and costs of systems associated with retrieval, transportation and storage of sludge. The overall goals for this testing were to collect detailed gas generation rate and composition data to ascertain the quantity and reactivity of the metallic uranium (and other reactive species) present in the K Basin sludge. The gas generation evaluation included four large-scale vessels (850 ml) and eight small-scale vessels (30 ml) in an all-metal, leak tight system. The tests were conducted for several thousand hours at ambient and elevated temperatures (32 C, 40 C, 60 C, 80 C, and 95 C) to accelerated the reactions and provide conclusive gas generation data within a reasonable testing period. The sludge used for these tests was collected from the KE Basin floor and canister barrels (containing damaged spent fuel elements) using a consolidated sampling technique (i.e., material from several locations was combined to form ''consolidated samples''). …
Date: September 12, 2000
Creator: Delegard, Calvin H.; Bryan, Samuel A.; Schmidt, Andrew J.; Bredt, Paul R.; King, Christopher M.; Sell, Rachel L. et al.
Object Type: Report
System: The UNT Digital Library
Government-Sponsored Enterprises: Creation of a Single Housing GSE Regulator (open access)

Government-Sponsored Enterprises: Creation of a Single Housing GSE Regulator

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the regulation of the housing government-sponsored enterprises (GSE)."
Date: September 12, 2000
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library