States

Anchor Toolkit - a secure mobile agent system (open access)

Anchor Toolkit - a secure mobile agent system

Mobile agent technology facilitates intelligent operation insoftware systems with less human interaction. Major challenge todeployment of mobile agents include secure transmission of agents andpreventing unauthorized access to resources between interacting systems,as either hosts, or agents, or both can act maliciously. The Anchortoolkit, designed by LBNL, handles the transmission and secure managementof mobile agents in a heterogeneous distributed computing environment. Itprovides users with the option of incorporating their security managers.This paper concentrates on the architecture, features, access control anddeployment of Anchor toolkit. Application of this toolkit in a securedistributed CVS environment is discussed as a case study.
Date: May 19, 1999
Creator: Mudumbai, Srilekha S.; Johnston, William & Essiari, Abdelilah
Object Type: Article
System: The UNT Digital Library
Application of Electron Backscattered Diffraction (EBSD) and Atomic Force Microscopy (AFM) to Determine Texture, Microtexture, and Grain Boundary Energies in Ceramics (open access)

Application of Electron Backscattered Diffraction (EBSD) and Atomic Force Microscopy (AFM) to Determine Texture, Microtexture, and Grain Boundary Energies in Ceramics

Crystallographic orientations in alumina (Al<sub>2</sub>0<sub>3</sub>) and magnesium aluminate spinel (MgAl<sub>2</sub>0<sub>4</sub>) were obtained using electron backscattered diffraction (EBSD) patterns. The texture and mesotexture (grain boundary misorientations) were random and no special boundaries were observed. The relative grain boundary energies were determined by thermal groove geometries using atomic force microscopy (AFM) to identify relationships between the grain boundary energies and misorientations.
Date: May 19, 1999
Creator: Glass, S. J.; Rohrer, G. S.; Saylor, D. M. & Vedula, V. R.
Object Type: Article
System: The UNT Digital Library
Cable Hot Shorts and Circuit Analysis in Fire Risk Assessment (open access)

Cable Hot Shorts and Circuit Analysis in Fire Risk Assessment

Under existing methods of probabilistic risk assessment (PRA), the analysis of fire-induced circuit faults has typically been conducted on a simplistic basis. In particular, those hot-short methodologies that have been applied remain controversial in regards to the scope of the assessments, the underlying methods, and the assumptions employed. To address weaknesses in fire PRA methodologies, the USNRC has initiated a fire risk analysis research program that includes a task for improving the tools for performing circuit analysis. The objective of this task is to obtain a better understanding of the mechanisms linking fire-induced cable damage to potentially risk-significant failure modes of power, control, and instrumentation cables. This paper discusses the current status of the circuit analysis task.
Date: May 19, 1999
Creator: LaChance, Jeffrey; Nowlen, Steven P. & Wyant, Frank
Object Type: Article
System: The UNT Digital Library
Clean Cities Award Winning Coalition: Atlanta (open access)

Clean Cities Award Winning Coalition: Atlanta

The Atlanta Clean City was the first to join the program in 1993, and has been successfully spreading the word about the benefits of alternative fuels ever since. They have already surpassed their year 2000 goal of operating more than 2,600 alternative fuel vehicles (AFVs). More than 30 stakeholders continue to help spur the Atlanta AFV market development by implementing innovative alternative fuel projects. Stakeholders actively support legislation that encourages the use of AFVs and sponsor workshops on advancing the choice.
Date: May 19, 1999
Creator: Kaiser, ICF
Object Type: Book
System: The UNT Digital Library
Clean Cities Award Winning Coalition: Chicago (open access)

Clean Cities Award Winning Coalition: Chicago

The Chicago area coalition marks its five-year anniversary in 1999 as a member of the Clean Cities Program. Their progress in the last five years has been remarkable as they advance the alternative fuel and vehicle markets, increase coalition membership, help support new alternative fuel vehicle (AFV) legislation, and educate fleet managers. The coalition boasts more than 90 stakeholders, including industry, government, environmental and academic organizations, and membership continues to grow. Thanks to dedicated coalition members' efforts, a variety of AFVs can be seen on Chicago's streets, including transit and school buses, taxicabs, sedans, vans, and trucks.
Date: May 19, 1999
Creator: Kaiser, ICF
Object Type: Book
System: The UNT Digital Library
Clean Cities Award Winning Coalition: Denver (open access)

Clean Cities Award Winning Coalition: Denver

The cities of Denver and Boulder comprise the Denver Clean Cities Coalition. They are committed to cleaner fuels, greener fleets, and bluer skies. More than 25 active stakeholders, including local government agencies, utilities, and private organizations, work together to advance alternative fuels and alternative fuel vehicles in the region. The city of Denver boasts several neighborhood electric vehicles for employees' use around town. The coalition has also sponsored alternative fuel workshops, special events, and has been successful in passing major alternative fuels legislation.
Date: May 19, 1999
Creator: Kaiser, ICF
Object Type: Book
System: The UNT Digital Library
Clean Cities Award Winning Coalition: Los Angeles (open access)

Clean Cities Award Winning Coalition: Los Angeles

As the second largest city in the United States, Los Angeles has more than 9 million motor vehicles on the road, accounting for up to 60% of the region's air pollution. Clean Cities Los Angeles has pioneered efforts in implementing innovation pollution reduction strategies, using alternative fuels and alternative fuel vehicles (AFVs). More than 475 compressed natural gas, liquefied natural gas, and electric vehicles (EVs) have been incorporated into city fleets. They've also launched Quick Charge L.A., a comprehensive EV infrastructure program that has established almost 200 EV charging stations at workplaces, event centers, rail stations, and other sites throughout the city. Clean Cities Los Angeles also leads the way in securing grants for AFV projects.
Date: May 19, 1999
Creator: Kaiser, ICF
Object Type: Book
System: The UNT Digital Library
Clean Cities Award Winning Coalition: San Diego (open access)

Clean Cities Award Winning Coalition: San Diego

Stakeholders in the San Diego coalition have already helped remove about 125 tons of nitrogen oxides and 867 tons of carbon dioxide every year since their inception in 1996. They are proud of their numerous accomplishments, including the San Diego Gas and Electric's installation of a solar chargeport, which can charge up to six electric vehicles simultaneously and at no cost. San Diego Regional Clean Cities Coalition will also soon be home to the first alternative fuel vehicle (AFV) showroom in the world, as the Regional Transportation Center plans to open during the summer of 2000. The million-dollar facility will display the latest AFV models, rent and demonstrate vehicles, and offer a fueling and service center with public access. An educational center is also part of the plan.
Date: May 19, 1999
Creator: Kaiser, ICF
Object Type: Book
System: The UNT Digital Library
Controlled densification of mullite for composite applications. (open access)

Controlled densification of mullite for composite applications.

As part of an effort to fabricate oxide-based fibrous monolithic ceramics, sintering of mullite has been examined. The effects of Y{sub 2}O{sub 3} additions on sinterability of sol-gel-derived mullite and on the resulting microstructure were evaluated over a range of compositions, sintering times, and temperatures. Electron microscopy, X-ray diffraction, differential thermal analysis, and density measurements indicated that the Y{sub 2}O{sub 3} additions promoted densification through formation of a Y-Si-Al-O liquid phase. This phase tended to solidify as a glass during normal processing, but could be crystallized by a two-step annealing process at 1300 and 1200 C. The four-point flexural strengths of mullite and mullite-5 Wt.% Y{sub 2}O{sub 3} were also examined.
Date: May 19, 1999
Creator: Cruse, T. A.
Object Type: Article
System: The UNT Digital Library
Department of Energy: Cost Estimates for the Hanford Tank Waste Remediation Project (open access)

Department of Energy: Cost Estimates for the Hanford Tank Waste Remediation Project

Correspondence issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the differences between GAO's 1998 report on the Department of Energy's (DOE) Hanford Tank Waste Remediation project and a 1998 report on the same project prepared by the Pacific Rim Enterprise Center, focusing on why the two reports reached substantially different conclusions about the growth in costs for the tank waste project."
Date: May 19, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Determination of worst case projected source term in tank 241-SY-102 (open access)

Determination of worst case projected source term in tank 241-SY-102

This document describes the methodology used to determine the worst case projected source term that could be in double-shell tank 241-SY-102 for the cross-site waste transfer to tank 241-AP-107. The worst case projected source term given in Table 4-1 is the weighted average of the tank waste sources with the addition of sufficient waste from a defined worst source tank to fill the tank to 416 inches. The projected source term in this document is not intended to represent what will be in tank 241-SY-102. Rather, it is a conservative bounding composition considering that the volume of waste that will be added from each current source is unknown.
Date: May 19, 1999
Creator: FOWLER, K.D.
Object Type: Report
System: The UNT Digital Library
Direct flow in 10.8 GeV/nucleon Au+Au collisions measured in experiment E917 at the AGS. (open access)

Direct flow in 10.8 GeV/nucleon Au+Au collisions measured in experiment E917 at the AGS.

Analysis of directed flow observable for protons and pions from Au+Au collisions at 10.8 GeV/nucleon from experiment E917 at the AGS is presented. Using a Fourier series expansion, the first Fourier component, {nu}{sub 1},was extracted as a function of rapidity for mid-central collisions (17-24%). Clear evidence for positive directed flow is found in the proton data, and a weak, possibly negative directed flow signal is observed for {pi}{sup +} and {pi}{sup {minus}}.
Date: May 19, 1999
Creator: Back, B. B.; Betts, R. R.; Britt, H. C.; Chang, J.; Chang, W. C.; Gillitzer, A. et al.
Object Type: Article
System: The UNT Digital Library
Effect of Hydroxyl Concentration on Chemical Sensitivity of Polyvinyl Alcohol/Carbon-Black Composite Chemiresistors (open access)

Effect of Hydroxyl Concentration on Chemical Sensitivity of Polyvinyl Alcohol/Carbon-Black Composite Chemiresistors

The sensitivity and selectivity of polyvinyl alcohol (PVA) / carbon black composite films have been found to vary depending upon the hydroxylation percentage ("-OH") of the polymer. These chemiresistors made from PVA films whose polymer backbone is 88% hydroxylated (PVA88) have a high sensitivity to water, while chemiresistors made from PVA75 have a higher sensitivity to methanol. The minor differences in polymer composition result in films with different Hildebrand volubility parameters. The relative responses of several different PVA-based chemiresistors to solvents with different volubility parameters are presented. In addition, polyvinyl acetate (PVAC) films with PVA88 are used in an array to distinguish the responses to methanol-water mixtures.
Date: May 19, 1999
Creator: Hughes, Robert C.; Patel, Sanjay V. & Yelton, W. Graham
Object Type: Article
System: The UNT Digital Library
Elemental mercury removal using a wet scrubber. (open access)

Elemental mercury removal using a wet scrubber.

Mercury (Hg) is a toxic metal that is emitted into the environment by both natural and human activities. Acute and chronic exposure to mercury and methyl mercury in humans results in central nervous system damage, kidney damage, and even death. Although some Hg emission sources have been regulated, coal-fired utilities have not been. In anticipation of federal regulations on mercury emissions from coal-fired power plants, Argonne National Laboratory (ANL) has designed a flue gas simulation system to study the removal of elemental mercury. The simulated flue gas enters the system and combines with the inlet mercury vapor (from a calibrated permeation tube), carried by nitrogen gas. This combined gas continues past the flow meter and the pressure gage to the reactor inlet. Inside the reactor chamber, the flue gas is sprayed with NOXSORB{reg_sign}, a chloric acid solution, which reacts with elemental mercury. The amount of reaction (oxidation) of elemental mercury is important since mercury in an oxidized form is highly soluble, In this form, the Hg can be picked up downstream by a wet scrubber from fossil-fuel burning utilities. Experiments on mercury removal from flue gases have been conducted at ANL, with the participation of a senior design team from …
Date: May 19, 1999
Creator: Gonzalez, E.; Livengood, C. D.; Martin, K.; Mendelsohn, M. H. & Zhou, C. Q.
Object Type: Article
System: The UNT Digital Library
Engineering task plan for rotary mode core sampling exhausters CAM high radiation interlock (open access)

Engineering task plan for rotary mode core sampling exhausters CAM high radiation interlock

The Rotary Mode Core Sampling (RMCS) system is primarily made up of the Rotary Mode Core Sample Trucks (RMCST) and the RMCS Exhausters. During RMCS operations an Exhauster is connected to a tank riser and withdraws gases from the tank dome vapor space at approximately 200 Standard Cubic Feet per Minute (SCFM). The gases are passed through two High Efficiency Particulate Air (HEPA) filters before passing out the exhaust stack to the atmosphere. A Continuous Air Monitor (CAM) monitors the exhaust gases in the exhaust stack for beta particle and gamma radiation. The CAM has a high radiation alarm output and a detector fail alarm output. The CAM alarms are currently connected to the data logger only. The CAM alarms require operator response per procedure LMHC 1998 but no automatic functions are initiated by the CAM alarms. Currently, there are three events that can cause an automatic shut down of the Exhauster. These are, Low Tank Pressure, Highnow Stack Flow and High HEPA Filter Differential Pressure (DP).
Date: May 19, 1999
Creator: Boger, R. M.
Object Type: Report
System: The UNT Digital Library
Epitaxially-Grown GaN Junction Field Effect Transistors (open access)

Epitaxially-Grown GaN Junction Field Effect Transistors

Junction field effect transistors (JFET) are fabricated on a GaN epitaxial structure grown by metal organic chemical vapor deposition (MOCVD). The DC and microwave characteristics of the device are presented. A junction breakdown voltage of 56 V is obtained corresponding to the theoretical limit of the breakdown field in GaN for the doping levels used. A maximum extrinsic transconductance (g<sub>m</sub>) of 48 mS/mm and a maximum source-drain current of 270 mA/mm are achieved on a 0.8 &micro; m gate JFET device at V<sub>GS</sub>= 1 V and V<sub>DS</sub>=15 V. The intrinsic transconductance, calculated from the measured g<sub>m</sub> and the source series resistance, is 81 mS/mm. The f<sub>T</sub> and f<sub>max</sub> for these devices are 6 GHz and 12 GHz, respectively. These JFETs exhibit a significant current reduction after a high drain bias is applied, which is attributed to a partially depleted channel caused by trapped hot-electrons in the semi-insulating GaN buffer layer. A theoretical model describing the current collapse is described, and an estimate for the length of the trapped electron region is given.
Date: May 19, 1999
Creator: Baca, A. G.; Chang, P. C.; Denbaars, S. P.; Lester, L. F.; Mishra, U. K.; Shul, R. J. et al.
Object Type: Article
System: The UNT Digital Library
Fabrication and characterization of oxide fibrous monoliths produced by coextrusion. (open access)

Fabrication and characterization of oxide fibrous monoliths produced by coextrusion.

Unidirectional fibrous monoliths (FMs) based on dense, strong ZrSiO{sub 4} cells that were surrounded by a porous, weaker ZrSiO{sub 4} cell-boundary phase were fabricated. A duplex filament was coextruded, sectioned, bundled, and the resulting bundle was extruded to form a new filament. This filament was cut and packed into plate and bar dies to produce FM test specimens. Four-point flexural tests were conducted on the cell material, cell-boundary material, and FMs. After testing, fracture surfaces and cross sections were examined by scanning electron microscopy. The FMs exhibited graceful failure in flexural testing, and the fracture surfaces exhibited clear evidence of crack deflection and delamination.
Date: May 19, 1999
Creator: Polzin, B. J.
Object Type: Article
System: The UNT Digital Library
Fatigue acceptance test limit criteria for larger diameter rolled thread fasteners (open access)

Fatigue acceptance test limit criteria for larger diameter rolled thread fasteners

This document describes a fatigue lifetime acceptance test criterion by which studs having rolled threads, larger than 1.0 inches (25 mm) in diameter, can be assured to meet minimum quality attributes associated with a controlled rolling process.
Date: May 19, 1999
Creator: Kephart, A. R.
Object Type: Article
System: The UNT Digital Library
Federal Oil Valuation: Efforts to Revise Regulations and an Analysis of Royalties in Kind (open access)

Federal Oil Valuation: Efforts to Revise Regulations and an Analysis of Royalties in Kind

Testimony issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO discussed the valuation of federal oil, focusing on: (1) the information the Minerals Management Service (MMS) used to justify the need for revising its regulations; (2) how MMS addressed concerns expressed by the oil industry and the states in developing these regulations; and (3) the feasibility of the government's taking its oil and gas royalties in kind, instead of in cash."
Date: May 19, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Fermi surfaces, Fermi patches, and Fermi arcs in high T{sub c} superconductors. (open access)

Fermi surfaces, Fermi patches, and Fermi arcs in high T{sub c} superconductors.

A defining property of metals is the existence of a Fermi surface: for two dimensions, a continuous contour in momentum space which separates occupied from unoccupied states. In this paper, I discuss angle resolved photoemission data on the cuprate superconductor BSCCO and argue that it is not best thought of in this conventional picture. Rather, the data are consistent with patches of finite area connected by more conventional arcs. Novel physics is associated with the patches, in that the states contained in a patch are dispersionless and thus interaction dominated. In the pseudogap phase, the patches are gapped out, leaving the Fermi arcs disconnected. This unusual situation may be the key to understanding the microscopic physics of the high temperature superconductors, in that the pairing correlations are strongest in the patches, yet the superfluid density lives only on the arcs.
Date: May 19, 1999
Creator: Norman, M. R.
Object Type: Article
System: The UNT Digital Library
Finemet versus ferrite -- Pros and cons (open access)

Finemet versus ferrite -- Pros and cons

There is a new magnetic alloy called Finemet which has very constant {mu}'{sub p}Qf up to {approximately} 2 kG and is very stable at high magnet flux density and temperature. It may be a good can-didate for high-gradient rf cavities. However, it has a rather low quality factor and is therefore very lossy. We compare the pros and cons of Finemet versus the common ferrite, when used in low-energy accelerating cavities, insertion for space-charge compensation, and barrier cavities.
Date: May 19, 1999
Creator: Qian, K.Y. Ng and Z.B.
Object Type: Article
System: The UNT Digital Library
Foreign Military Sales: Recovery of Nonrecurring Research, Development, and Production Costs (open access)

Foreign Military Sales: Recovery of Nonrecurring Research, Development, and Production Costs

Correspondence issued by the General Accounting Office with an abstract that begins "GAO provided information on the Department of Defense's efforts to recover the nonrecurring research, development, and production costs from its Foreign Military Sales (FMS) Program trust fund for items that were delivered to FMS customers."
Date: May 19, 1999
Creator: United States. General Accounting Office.
Object Type: Text
System: The UNT Digital Library
Fracture toughness measurements on a glass bonded sodalite high-level waste form. (open access)

Fracture toughness measurements on a glass bonded sodalite high-level waste form.

The electrometallurgical treatment of metallic spent nuclear fuel produces two high-level waste streams; cladding hulls and chloride salt. Argonne National Laboratory is developing a glass bonded sodalite waste form to immobilize the salt waste stream. The waste form consists of 75 Vol.% crystalline sodalite (containing the salt) with 25 Vol.% of an ''intergranular'' glassy phase. Microindentation fracture toughness measurements were performed on representative samples of this material using a Vickers indenter. Palmqvist cracking was confirmed by post-indentation polishing of a test sample. Young's modulus was measured by an acoustic technique. Fracture toughness, microhardness, and Young's modulus values are reported, along with results from scanning electron microscopy studies.
Date: May 19, 1999
Creator: DiSanto, T.; Goff, K. M.; Johnson, S. G. & O'Holleran, T. P.
Object Type: Article
System: The UNT Digital Library
Illegal Immigration: Status of Southwest Border Strategy Implementation (open access)

Illegal Immigration: Status of Southwest Border Strategy Implementation

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a legislative requirement, GAO provided information on the Attorney General's strategy for reducing and deterring illegal entry along the southwest border, focusing on: (1) the Immigration and Naturalization Service's (INS) progress in implementing the southwest border strategy during fiscal year (FY) 1998; (2) interim results of the strategy; and (3) actions taken on GAO's recommendation that the Attorney General develop and implement a plan for formal, cost-effective, comprehensive, and systematic evaluation of the strategy."
Date: May 19, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library