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An agent-based tool for infrastructure interdependency policy analysis. (open access)

An agent-based tool for infrastructure interdependency policy analysis.

Complex Adaptive Systems (CAS) can be applied to investigate complex infrastructure interdependencies such as those between the electric power and natural gas markets. These markets are undergoing fundamental transformations including major changes in electric generator fuel sources. Electric generators that use natural gas as a fuel source are rapidly gaining market share. These generators introduce direct interdependency between the electric power and natural gas markets. These interdependencies have been investigated using the emergent behavior of CAS model agents within the Spot Market Agent Research Tool Version 2.0 Plus Natural Gas (SMART II+).
Date: December 14, 2000
Creator: North, M. J.
System: The UNT Digital Library
Experimental assessment of gradient plasticity (open access)

Experimental assessment of gradient plasticity

Classical plasticity theories generally assume that the stress at a point is a function of strain at that point only. However, when gradients in strain become significant, this localization assumption is no longer valid. A common factor in the failure of these conventional models is that, since they do not account for the strain gradients, they do not display a size effect. This effect is seen experimentally when the scale of the phenomenon of interest is on the order of several microns. At this scale, strain gradients are of a significant magnitude as compared to the overall strain and must be considered for models to accurately capture observed phenomena. The mechanics community has been actively involved in the development of strain gradient theories for many years. Recently, interest in this area has been rekindled and several new approaches have appeared in the literature. Two different approaches are currently being evaluated: one approach considers strain gradients as internal variables which do not introduce work conjugate higher order stresses, and another approach considers the strain gradients as internal degrees of freedom which requires work conjugate higher order stresses. Experiments are being performed to determine which approach models material behavior accurately with the …
Date: December 14, 2000
Creator: Barney, M M; Campbell, G H; Stolken, J S; Schwartz, A J; Plitzko, J; King, W E et al.
System: The UNT Digital Library
Fundamental studies of ceramic/metal interfacial reactions at elevated temperatures. (open access)

Fundamental studies of ceramic/metal interfacial reactions at elevated temperatures.

This work characterizes the interfaces resulting from exposing oxide and non-oxide ceramic substrates to zirconium metal and stainless steel-zirconium containing alloys. The ceramic/metal systems together were preheated at about 600 C and then the temperatures were increased to the test maximum temperature, which exceeded 1800 C, in an atmosphere of high purity argon. Metal samples were placed onto ceramic substrates, and the system was heated to elevated temperatures past the melting point of the metallic specimen. After a short stay at the peak temperature, the system was cooled to room temperature and examined. The chemical changes across the interface and other microstructural developments were analyzed with energy dispersive spectroscopy (EDS). This paper reports on the condition of the interfaces in the different systems studied and describes possible mechanisms influencing the microstructure.
Date: December 14, 2000
Creator: McDeavitt, S. M.; Billings, G. W. & Indacochea, J. E.
System: The UNT Digital Library
Microstructural characterization of halite inclusion in a glass-bonded ceramic waste form. (open access)

Microstructural characterization of halite inclusion in a glass-bonded ceramic waste form.

A glass-bonded ceramic waste form is being developed to immobilize radioactively contaminated chloride waste salts generated during the conditioning of spent sodium-bonded nuclear fuel for disposal. The waste salt is first mixed with zeolite A to occlude the salt into cavities in the zeolite structure. The salt-loaded zeolite is then mixed with a borosilicate glass and consolidated by hot isostatic pressing. During this process, the zeolite converts to the mineral sodalite, which retains most of the waste salt, and small amounts of halite are generated. Halite inclusions have been observed within micron- to submicron-sized pores that form within the glass phase in the vicinity of the sodalite/glass interface. These inclusions are important because they may contain small amounts of radionuclide contaminants (eg {sup 135}Cs and {sup 129}I),and may affect the corrosion behavior of the waste form. Optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to characterize the chemical nature and distribution of halite inclusions in the waste form.
Date: December 14, 2000
Creator: Luo, J. S. & Ebert, W. L.
System: The UNT Digital Library
SMART II : the spot market agent research tool version 2.0. (open access)

SMART II : the spot market agent research tool version 2.0.

Argonne National Laboratory (ANL) has worked closely with Western Area Power Administration (Western) over many years to develop a variety of electric power marketing and transmission system models that are being used for ongoing system planning and operation as well as analytic studies. Western markets and delivers reliable, cost-based electric power from 56 power plants to millions of consumers in 15 states. The Spot Market Agent Research Tool Version 2.0 (SMART II) is an investigative system that partially implements some important components of several existing ANL linear programming models, including some used by Western. SMART II does not implement a complete model of the Western utility system but it does include several salient features of this network for exploratory purposes. SMART II uses a Swarm agent-based framework. SMART II agents model bulk electric power transaction dynamics with recognition for marginal costs as well as transmission and generation constraints. SMART II uses a sparse graph of nodes and links to model the electric power spot market. The nodes represent power generators and consumers with distinct marginal decision curves and varying investment capital as well individual learning parameters. The links represent transmission lines with individual capacities taken from a range of central …
Date: December 14, 2000
Creator: North, M. J. N.
System: The UNT Digital Library
SMART II+ : the spot market agent research tool version 2.0 plus natural gas. (open access)

SMART II+ : the spot market agent research tool version 2.0 plus natural gas.

Complex Adaptive Systems (CAS) can be applied to investigate complex infrastructure interdependencies including those between the electric power and natural gas markets. The electric power and natural gas markets are undergoing fundamental transformations. These transformations include major changes in electric generator fuel sources. Electric generators that use natural gas as a fuel source are rapidly gaining market share. Electric generators using natural gas introduce direct interdependency between the electric power and natural gas markets. The interdependencies between the electric power and natural gas markets introduced by these generators can be investigated using the emergent behavior of CAS model agents.
Date: December 14, 2000
Creator: North, M. J. N.
System: The UNT Digital Library
Use of Uniformly Distributed Concentrated Sunlight for Highly Accelerated Testing of Coatings (open access)

Use of Uniformly Distributed Concentrated Sunlight for Highly Accelerated Testing of Coatings

NREL has developed a new ultraviolet (UV) light concentrator that allows material samples to be subjected to uniform intensity levels of 50-100X solar UV at closely controlled sample exposure temperatures. In collaboration with industry, representative coating systems have been exposed without introducing unrealistic degradation mechanisms. Furthermore, correlations have been derived between these highly accelerated test conditions and results obtained at 1-2 suns. Such information is used to predict the degradation of materials in real-world applications. These predictions are compared with measured in-service performance losses to validate the approach. This allows valuable information to be obtained in greatly reduced timeframes, which can provide tremendous competitive advantage in the commercial marketplace.
Date: December 14, 2000
Creator: Jorgensen, G.; Bingham, C.; King, D.; Lewandowski, A.; Netter, J.; Terwilliger, K. et al.
System: The UNT Digital Library
Argonne's contribution to regional development : successful examples. (open access)

Argonne's contribution to regional development : successful examples.

Argonne National Laboratory's mission is basic research and technology development to meet national goals in scientific leadership, energy technology, and environmental quality. In addition to its core missions as a national research and development center, Argonne has exerted a positive impact on its regional economic development, has carried out outstanding educational programs not only for college/graduate students but also for pre-college students and teachers, and has fostered partnerships with universities for research collaboration and with industry for shaping the new technological frontiers.
Date: November 14, 2000
Creator: Chang, Y. I.
System: The UNT Digital Library
Characteristics of hydride precipitation and reorientation in spent-fuel cladding. (open access)

Characteristics of hydride precipitation and reorientation in spent-fuel cladding.

The morphology, number density, orientation, distribution, and crystallographic aspects of Zr hydrides in Zircaloy fuel cladding play important roles in fuel performance during all phases before and after discharge from the reactor, i.e., during normal operation, transient and accident situations in the reactor, temporary storage in a dry cask, and permanent storage in a waste repository. In the past, partly because of experimental difficulties, hydriding behavior in irradiated fuel cladding has been investigated mostly by optical microscopy (OM). In the present study, fundamental metallurgical and crystallographic characteristics of hydride precipitation and reorientation were investigated on the microscopic level by combined techniques of OM and transmission electron and scanning electron microscopy (TEM and SEM) of spent-fuel claddings discharged from several boiling and pressurized water reactors (BWRs and PWRs). Defueled sections of standard and Zr-lined Zircaloy-2 fuel claddings, irradiated to fluences of {approx}3.3 x 10{sup 21} n cm{sup {minus}2} and {approx}9.2 x 10{sup 21} n cm{sup {minus}2} (E > 1 MeV), respectively, were obtained from spent fuel rods discharged from two BWRs. Sections of standard and low-tin Zircaloy-4 claddings, irradiated to fluences of {approx}4.4 x 10{sup 21} n cm{sup {minus}2}, {approx}5.9 x 10{sup 21} n cm{sup {minus}2}, and {approx}9.6 x 10{sup 21} …
Date: November 14, 2000
Creator: Chung, H. M.; Strain, R. V. & Billone, M. C.
System: The UNT Digital Library
Charged Kaons at the Main Injector - CKM (open access)

Charged Kaons at the Main Injector - CKM

None
Date: November 14, 2000
Creator: Milstene, Caroline
System: The UNT Digital Library
A combined microprobe and high-resolution mass spectrometer for materials aging studies (open access)

A combined microprobe and high-resolution mass spectrometer for materials aging studies

None
Date: November 14, 2000
Creator: Behrens, R.; Whaley, J. & Bastasz, R.
System: The UNT Digital Library
Combined recoil and threshold resummation for hard scattering cross sections (open access)

Combined recoil and threshold resummation for hard scattering cross sections

None
Date: November 14, 2000
Creator: Laenen, E.; Sterman, G. & Vogelsang, W.
System: The UNT Digital Library
Design and construction of the CDF central outer tracker (open access)

Design and construction of the CDF central outer tracker

None
Date: November 14, 2000
Creator: Burkett, Kevin
System: The UNT Digital Library
Evaluation of Laser-Induced Breakdown Spectroscopy as Technetium Monitor (open access)

Evaluation of Laser-Induced Breakdown Spectroscopy as Technetium Monitor

The analytical figure of merit of a laser-induced breakdown (LIBS) system was evaluated for technetium measurements in liquid. LIBS data of elements that have similar properties to Tc such as Cr, Mn, and Re were studied. Various optical geometries which produce the laser spark in and at the liquid sample were tested. The calibration curve for Mn, Cr, and Re were obtained at the optimized experimental conditions with bulk liquid and liquid jet. We found that measurements using a liquid jet provide better detection limits than the bulk liquid measurements. The detection limits of Mg, Cr, Mn, and Re in a liquid jet measurement are found to be 0.1, 0.4, 0.7, and 10 ppm, respectively.
Date: November 14, 2000
Creator: Spencer, W. A.; Yueh, F. Y.; Sharma, R. C.; Singh, J. P. & Zhang, H.
System: The UNT Digital Library
Fully differential QCD corrections to single top quark final states. (open access)

Fully differential QCD corrections to single top quark final states.

The authors have performed a fully differential calculation of QCD corrections to electroweak production of single top quarks. The method used allows for jet definitions and experimental cuts. The corresponding computer code passes the necessary check of reproducing the previously known total rate. First examination of the rapidity and transverse momentum of the top quark shows the corrections to be flat relative to leading order. Additional phenomenological studies are in order. Further work is in progress on the corrections to t-b-jet final states which will give a comprehensive set of tools for studying single-top-quark production at future hadron-hadron colliders.
Date: November 14, 2000
Creator: Harris, B. W.; Laenen, E.; Phaf, L.; Sullivan, Z. & Weinzierl, S.
System: The UNT Digital Library
Physics potential and status of D-Zero upgrade at Fermilab (open access)

Physics potential and status of D-Zero upgrade at Fermilab

None
Date: November 14, 2000
Creator: Yu, Jaehoon
System: The UNT Digital Library
The port card for the silicon vertex detector upgrade of the Collider Detector at Fermilab (open access)

The port card for the silicon vertex detector upgrade of the Collider Detector at Fermilab

None
Date: November 14, 2000
Creator: al., Jeff Andresen et
System: The UNT Digital Library
Power corrections in eikonal cross sections (open access)

Power corrections in eikonal cross sections

None
Date: November 14, 2000
Creator: Laenen, E.; Sterman, G. & Vogelsang, W.
System: The UNT Digital Library
Report of the Tevatron Higgs working group. (open access)

Report of the Tevatron Higgs working group.

Despite the success of the Standard Model (SM), which provides a superb description of a wide range of experimental particle physics data, the dynamics responsible for electroweak symmetry breaking is still unknown. Its elucidation remains one of the primary goals of future high energy physics experimentation. Present day global fits to precision electroweak data based on the Standard Model favor the existence of a weakly-interacting scalar Higgs boson, which is a remnant of elementary scalar dynamics that drives electroweak symmetry breaking. The only known viable theoretical framework incorporating light elementary scalar fields employs low-energy supersymmetry, where the scale of supersymmetry breaking is {Omicron} (1 TeV). The Higgs sector of the Minimal Supersymmetric extension of the Standard Model (MSSM) is of particular interest because it predicts the existence of a light CP-even neutral Higgs boson with a mass below about 130 GeV. Moreover, over a significant portion of the MSSM parameter space, the properties of this scalar are indistinguishable from those of the SM Higgs boson.
Date: November 14, 2000
Creator: Carena, M.; Conway, J. S.; Haber, H. E.; Hobbs, J. D.; Harris, B. W.; Kuhlmann, S. et al.
System: The UNT Digital Library
Review of US Nanocorp - SNL Joint Development of Thermal-Sprayed Thin-Film Cathodes for Thermal Batteries (open access)

Review of US Nanocorp - SNL Joint Development of Thermal-Sprayed Thin-Film Cathodes for Thermal Batteries

The use of plasma spray to deposit thin metal-sulfide cathode films is described in this paper. Conventional electroactive stack components in thermal batteries are constructed from pressed-powder parts that are difficult to fabricate in large diameters in thicknesses <0.010. Plasma-sprayed electrodes do not steer from this difficulty, allowing greater energy densities and specific energies to be realized. Various co-spraying agents have been found suitable for improving the mechanical as well as electrochemical properties of plasma-sprayed cathodes for thermal batteries. These electrodes generally show equal or improved performance over conventional pressed-powder electrodes. A number of areas for future growth and development of plasma-spray technology is discussed.
Date: November 14, 2000
Creator: GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.; DAI,JINXIANG; XIAO,T. DANNY & REISNER,DAVID E.
System: The UNT Digital Library
A Scanning Tunneling Microscopy Study of As/Ge(mnn) and P/Ge(mnn) Surfaces (open access)

A Scanning Tunneling Microscopy Study of As/Ge(mnn) and P/Ge(mnn) Surfaces

Ge(mnn) surfaces between (100) and (111) were annealed under either arsine or phosphine in a metal-organic chemical vapor deposition chamber, then imaged with a scanning tunneling microscope. In general, arsine-exposed Ge surfaces are facetted, while phosphine-exposed surfaces remain flat. For the arsine-exposed Ge surfaces, four stable facetting directions have been identified: (100), (11,3,3), (955), and (111).
Date: November 14, 2000
Creator: McMahon, W. E. & Olsen, J. M.
System: The UNT Digital Library
Smooth- and enhanced-tube heat transfer and pressure drop : Part I. Effect of Prandtl number with air, water, and glycol/water mixtures. (open access)

Smooth- and enhanced-tube heat transfer and pressure drop : Part I. Effect of Prandtl number with air, water, and glycol/water mixtures.

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics in laminar, transitional, and turbulent flow through one smooth tube and twenty-three enhanced tubes. The working fluids for the experiments were air, water, ethylene glycol, and ethylene glycol/water mixtures; Prandtl numbers (Pr) ranged from 0.7 to 125.3. The smooth-tube experiments were carried out with Pr values of 0.7, 6.8, 24.8, 39.1, and 125.3; Pr values of 0.7, 6.8, and 24.8 were tested with enhanced tubes. Reynolds number (Re) range (based on the maximum internal diameter of a tube) was 200 to 55,000, depending on Prandtl number and tube geometry. The results are presented and discussed in this paper.
Date: November 14, 2000
Creator: Obot, N. T.; Das, L. & Rabas, T. J.
System: The UNT Digital Library
Smooth- and enhanced-tube heat transfer and pressure drop : Part II. The role of transition to turbulent flow. (open access)

Smooth- and enhanced-tube heat transfer and pressure drop : Part II. The role of transition to turbulent flow.

The objectives of this presentation are two-fold: first, to demonstrate the connection between the attainable coefficients and transition to turbulent flow by using the transition-based corresponding states method to generalize results obtained with smooth tubes and enhanced tubes, and second, to provide guidelines on the calculation of heat transfer coefficients from pressure-drop data and vice versa by using the transition concept or the functional law of corresponding states.
Date: November 14, 2000
Creator: Obot, N. T.; Das, L. & Rabas, T. J.
System: The UNT Digital Library
Studies of cosolvent systems in supercritical ethane using solvated electrons. (open access)

Studies of cosolvent systems in supercritical ethane using solvated electrons.

In this paper, pulse-radiolytic studies of the methanol-ethane cosolvent system are carried out. Our results show that at temperatures below approximately 110 C, there are high local concentrations of alcohols (clusters) that are capable of solvating an electron, suggesting a size of approximately 4-5 methanol molecules at approximately 0.15 mole fraction alcohol. Reactions have been carried out between these solvated electrons and silver ions that are (presumably) dissolved in other small clusters of alcohols. These results show that the reaction between species in two different clusters is approximately 2 orders of magnitude slower than diffusion-controlled reactions.
Date: November 14, 2000
Creator: Dimitrijevic, N. M.; Bartels, D. M.; Jonah, C. D. & Takahashi, K.
System: The UNT Digital Library