Acceleration for a High Energy Muon Collider. (open access)

Acceleration for a High Energy Muon Collider.

None
Date: January 5, 2000
Creator: Berg, J. S.
Object Type: Article
System: The UNT Digital Library
Acoustic Detecting and Locating Gas Pipe Line Infringement Quarterly Report: Number 6 (open access)

Acoustic Detecting and Locating Gas Pipe Line Infringement Quarterly Report: Number 6

The power point presentation for the Natural Gas Technologies II Conference held on February 8-11, 2004 in Phoenix AZ, published the presentations made at the conference, therefore required all presenters to submit their presentation prior to November 2003. However in the remainder of year, significant new test data became available which were incorporated in the actual presentation made at the Natural Gas Technologies II Conference. The 6th progress report presents the updated actual slide show used during the paper presentation by Richard Guiler.
Date: January 5, 2004
Creator: LOTH, John L.; MORRIS, GARY J.; PALMER, GEORGE M. & GUILER, RICHARD
Object Type: Report
System: The UNT Digital Library
Actinic Mask Inspection at the Als: Risk Reduction Activities for 2003 (open access)

Actinic Mask Inspection at the Als: Risk Reduction Activities for 2003

This document reports on risk reduction activities performed at the VNL during CY2003 as a part of the Lith-343 actinic inspection project funded by International SEMATECH. The risk reduction activities described in this document comprise deliverable items 3.1.3, 3.1.4, 3.1.5 and 3.1.6 of Amendment 6 to the VNL EUV mask blank technology transfer contract.
Date: January 5, 2004
Creator: Barty, A.; Levesque, R.; Ayers, J.; Liu, Y.; Gullikson, E. & Barale, P.
Object Type: Report
System: The UNT Digital Library
Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon (open access)

Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon

Rockfishes (Sebastes spp.) support one of the most economically important fisheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated {sup 14}C signal by emphasizing the utility of the time-specific marker created by the initial rise of bomb-{sup 14}C. Second, the bomb-generated {sup 14}C signal retained in fish otoliths was used to validate the age and age estimation methodology of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year's growth of quillback rockfish otoliths were plotted against estimated birth year producing a {sup 14}C time series spanning 1950 to 1985. The initial rise of bomb-{sup 14}C from pre-bomb levels ({approx} -90 {per_thousand}) occurred in 1959 {+-} 1 year and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values in 1967 (+105.4 {per_thousand}), with a subsequent declining trend …
Date: January 5, 2005
Creator: Kerr, L A; Andrews, A H; Munk, K; Coale, K H; Frantz, B R; Cailliet, G M et al.
Object Type: Article
System: The UNT Digital Library
Analytic crack solutions for tilt fields around hydraulic fractures (open access)

Analytic crack solutions for tilt fields around hydraulic fractures

The recent development of downhole tiltmeter arrays for monitoring hydraulic fractures has provided new information on fracture growth and geometry. These downhole arrays offer the significant advantages of being close to the fracture (large signal) and being unaffected by the free surface. As with surface tiltmeter data, analysis of these measurements requires the inversion of a crack or dislocation model. To supplement the dislocation models of Davis [1983], Okada [1992] and others, this work has extended several elastic crack solutions to provide tilt calculations. The solutions include constant-pressure 2D, penny-shaped, and 3D-elliptic cracks and a 2D-variable-pressure crack. Equations are developed for an arbitrary inclined fracture in an infinite elastic space. Effects of fracture height, fracture length, fracture dip, fracture azimuth, fracture width and monitoring distance on the tilt distribution are given, as well as comparisons with the dislocation model. The results show that the tilt measurements are very sensitive to the fracture dimensions, but also that it is difficult to separate the competing effects of the various parameters.
Date: January 5, 2000
Creator: Warpinski, N.R.
Object Type: Article
System: The UNT Digital Library
Availability Analysis of the Ventilation Stack CAM Interlock System (open access)

Availability Analysis of the Ventilation Stack CAM Interlock System

Ventilation Stack Continuous Air Monitor (CAM) Interlock System failure modes, failure frequencies and system availability have been evaluated for the RPP. The evaluation concludes that CAM availability is as high as assumed in the safety analysis and that the current routine system surveillance is adequate to maintain this availability. Further, requiring an alarm to actuate upon CAM failure is not necessary to maintain the availability credited in the safety analysis, nor is such an arrangement predicted to significantly improve system availability. However, if CAM failures were only detected by the 92-day functional tests required in the Authorization Basis (AB), CAM availability would be much less than that credited in the safety analysis. Therefore it is recommended that the current surveillance practice of daily simple system checks, 30-day source checks and 92-day functional tests be continued in order to maintain CAM availability.
Date: January 5, 2000
Creator: YOUNG, J.
Object Type: Report
System: The UNT Digital Library
Beam shaping element for compact fiber injection systems (open access)

Beam shaping element for compact fiber injection systems

Injection of high power, multi-mode laser profiles into a fiber optic delivery system requires controlling a number of injection parameters to maximize throughput and minimize concerns for optical damage both at the entrance and exit faces of the fiber optic. A simple method for simultaneously achieving a compact fiber injection geometry and control of these injection parameters, independent of the input source characteristics, is provided by a refractive lenslet array and simple injection lens configuration. Design criteria together with analytical and experimental results for the refractive lenslet array and short focal length injection lens are presented. This arrangement provides a uniform spatial intensity distribution at the fiber injection plane to a large degree independent of the source mode structure, spatial profile, divergence, size, and/or alignment to the injection system. This technique has application to a number of laser systems where uniform illumination of a target or remote delivery of high peak power is desired.
Date: January 5, 2000
Creator: Weichman, L.S.; Dickey, F.M. & Shagam, R.N.
Object Type: Article
System: The UNT Digital Library
Biological impacts and context of network theory (open access)

Biological impacts and context of network theory

Many complex systems can be represented and analyzed as networks, and examples that have benefited from this approach span the natural sciences. For instance, we now know that systems as disparate as the World-Wide Web, the Internet, scientific collaborations, food webs, protein interactions and metabolism all have common features in their organization, the most salient of which are their scale-free connectivity distributions and their small-world behavior. The recent availability of large scale datasets that span the proteome or metabolome of an organism have made it possible to elucidate some of the organizational principles and rules that govern their function, robustness and evolution. We expect that combining the currently separate layers of information from gene regulatory-, signal transduction-, protein interaction- and metabolic networks will dramatically enhance our understanding of cellular function and dynamics.
Date: January 5, 2007
Creator: Almaas, E
Object Type: Article
System: The UNT Digital Library
Changes in delta-Plutonium due to self-irradiation aging observed by Continuous in-situ X-ray Scattering (open access)

Changes in delta-Plutonium due to self-irradiation aging observed by Continuous in-situ X-ray Scattering

The aging in plutonium is predominantly caused by its internal self-irradiation. The self-irradiation in Pu-239 is by the decay process of transmuting the Pu atom into uranium atom and emitting an {alpha}-particle. Most of the lattice damage comes from the uranium recoil resulting in Frenkel-type defects consisting of vacancies and self-interstitial atoms, helium in-growth and defect clusters and possibly even though it is not yet observed, the generation of voids. As part of the stockpile stewardship, it is important to understand the changes in the structure and microstructures and their correlations to the physical properties. Changes in the physical properties have a direct relationship to the quality of the structure, in terms of formation of defects and defect clustering, accumulation of voids, grain boundaries, phase changes and etc. which can adversely affect the stability of the material. These changes are very difficult to monitor because of the high activity of the sample, high atomic number making x-ray and synchrotron probe into the bulk very difficult (neutron probe is not feasible) and the long life time which normally requires decades to measure. In this paper we describe the development of an in-situ in-house transmission x-ray diffraction (XRD) experimental technique used to …
Date: January 5, 2007
Creator: Saw, C K; Chung, B W & Wall, M A
Object Type: Article
System: The UNT Digital Library
Characterization of an energy storage capacitor in abnormal thermal environments (open access)

Characterization of an energy storage capacitor in abnormal thermal environments

There are applications of high-voltage, energy-storage, capacitors where it is desirable that the energy storage capability can be reliably and predictably negated in abnormal environments such as fire. This property serves as a safety feature to prevent events of unintended consequence. The present paper describes studies of the thermal response characteristics of a cylindrically wound, discrete Mylar film/foil capacitor design. The experimental setups that simulate fires will be presented. Three different heat input geometries were employed: uniform radial input, spot radial input, and axial input. Heat input was controlled via feedback system to maintain specific temperature ramp rates. Both capacitor voltage and current were monitored during the thermal excursion to ascertain the failure temperature, i.e. when the capacitor permanently shorts. Temperature of failure data is presented for the three heat input cases along with a statistical analysis of the results and application implications. The physics of failure will be described in terms of the thermal/mechanical properties of the Mylar.
Date: January 5, 2000
Creator: Edwards, L. R.; Chen, K. C. & Baron, R. V.
Object Type: Article
System: The UNT Digital Library
Cold Vacuum Drying (CVD) Facility Acceptance for Beneficial Use (open access)

Cold Vacuum Drying (CVD) Facility Acceptance for Beneficial Use

This document provides a checklist of the items required for turnover of the Cold Vacuum Drying Facility from the Construction Projects organization to the Operations organization. This document will be updated periodically to document completion of additional deliverables.
Date: January 5, 2000
Creator: Brisbin, S. A.
Object Type: Report
System: The UNT Digital Library
Complexation of Gluconate with Uranium(VI) in Acidic Solutions: Thermodynamic Study with Structural Analysis (open access)

Complexation of Gluconate with Uranium(VI) in Acidic Solutions: Thermodynamic Study with Structural Analysis

Within the pC{sub H} range of 2.5 to 4.2, gluconate forms three uranyl complexes UO{sub 2}(GH{sub 4}){sup +}, UO{sub 2}(GH{sub 3})(aq), and UO{sub 2}(GH{sub 3})(GH{sub 4}){sup -}, through the following reactions: (1) UO{sub 2}{sup 2+} + GH{sub 4}{sup -} = UO{sub 2}(GH{sub 4}){sup +}, (2) UO{sub 2}{sup 2+} + GH{sub 4}{sup -} = UO{sub 2}(GH{sub 3})(aq) + H{sup +}, and (3) UO{sub 2}{sup 2+} + 2GH{sub 4}{sup -} = UO{sub 2}(GH{sub 3})(GH{sub 4}){sup -} + H{sup +}. Complexes were inferred from potentiometric, calorimetric, NMR, and EXAFS studies. Correspondingly, the stability constants and enthalpies were determined to be log {Beta}{sub 1} = 2.2 {+-} 0.3 and {Delta}H{sub 1} = 7.5 {+-} 1.3 kJ mol{sup -1} for reaction (1), log {Beta}{sub 2} = -(0.38 {+-} 0.05) and {Delta}H{sub 2} = 15.4 {+-} 0.3 kJ mol{sup -1} for reaction (2), and log {Beta}{sub 3} = 1.3 {+-} 0.2 and {Delta}H{sub 3} = 14.6 {+-} 0.3 kJ mol{sup -1} for reaction (3), at I = 1.0 M NaClO{sub 4} and t = 25 C. The UO{sub 2}(GH{sub 4}){sup +} complex forms through the bidentate carboxylate binding to U(VI). In the UO{sub 2}(GH{sub 3})(aq) complex, hydroxyl-deprotonated gluconate (GH{sub 3}{sup 2-}) coordinates to U(VI) through the …
Date: January 5, 2009
Creator: Zhang, Zhicheng; Helms, G.; Clark, S. B.; Tian, Guoxin; Zanonato, PierLuigi & Rao, Linfeng
Object Type: Article
System: The UNT Digital Library
Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z~6 Quasars II: A Sample of 19 Quasars (open access)

Constraining the Evolution of the Ionizing Background and the Epoch of Reionization with z~6 Quasars II: A Sample of 19 Quasars

We study the evolution of the ionization state of the intergalactic medium (IGM) at the end of the reionization epoch using moderate resolution spectra of a sample of nineteen quasars at 5.74 < z{sub em} < 6.42 discovered in the Sloan Digital Sky Survey. Three methods are used to trace IGM properties: (a) the evolution of the Gunn-Peterson (GP) optical depth in the Ly{alpha}, {beta}, and {gamma} transitions; (b) the distribution of lengths of dark absorption gaps, and (c) the size of HII regions around luminous quasars. Using this large sample, we find that the evolution of the ionization state of the IGM accelerated at z > 5.7: the GP optical depth evolution changes from {tau}{sub GP}{sup eff} {approx} (1 + z){sup 4.3} to (1 + z){sup {approx}> 11}, and the average length of dark gaps with {tau} > 3.5 increases from < 10 to > 80 comoving Mpc. The dispersion of IGM properties along different lines of sight also increases rapidly, implying fluctuations by a factor of {approx}> 4 in the UV background at z > 6, when the mean free path of UV photons is comparable to the correlation length of the star forming galaxies that are thought …
Date: January 5, 2006
Creator: Fan, X; Strauss, M A; Becker, R H; White, R L; Gunn, J E; Knapp, G R et al.
Object Type: Article
System: The UNT Digital Library
Creation of hot radiation environments in laser-driven targets (open access)

Creation of hot radiation environments in laser-driven targets

None
Date: January 5, 2006
Creator: Hinkel, D. E.; Schneider, M. B.; Young, B. K.; Langdon, A. B.; Williams, E. A.; Rosen, M. D. et al.
Object Type: Article
System: The UNT Digital Library
CsBr Photocathode at 257nm: A Rugged High Current Density Electron Source (open access)

CsBr Photocathode at 257nm: A Rugged High Current Density Electron Source

There is a continuing need for high intensity electron sources that will operate in demountable vacuum and can be externally modulated. Materials with wide bandgap, e.g. diamond, are rugged but need photon energies exceeding the bandgap to emit efficiently and this rules out the use of CW lasers. We have found that a photocathode of CsBr is both adequately intense(>150A/cm{sup 2}) and rugged and can be excited with photons of energy of 4.8eV(257nm). This is below the energy gap of CsBr(7.3eV) but such operation can be explained by the presence of intraband states about 4eV below the conduction band minimum.
Date: January 5, 2007
Creator: Liu, Zhi; Maldonado, Juan; Sun, Yun; Pianetta, Piero; Pease, R.F.W. & /SLAC, SSRL
Object Type: Article
System: The UNT Digital Library
Determining the mechanical constitutive properties of metals as a function of strain rate and temperature: A combined experimental and modeling approach (open access)

Determining the mechanical constitutive properties of metals as a function of strain rate and temperature: A combined experimental and modeling approach

OAK-135 Development and validation of constitutive models for polycrystalline materials subjected to high strain rate loading over a range of temperatures are needed to predict the response of engineering materials to in-service type conditions (foreign object damage, high-strain rate forging, high-speed sheet forming, deformation behavior during forming, response to extreme conditions, etc.). To account accurately for the complex effects that can occur during extreme and variable loading conditions, requires significant and detailed computational and modeling efforts. These efforts must be closely coupled with precise and targeted experimental measurements that not only verify the predictions of the models, but also provide input about the fundamental processes responsible for the macroscopic response. Achieving this coupling between modeling and experimentation is the guiding principle of this program. Specifically, this program seeks to bridge the length scale between discrete dislocation interactions with grain boundaries and continuum models for polycrystalline plasticity. Achieving this goal requires incorporating these complex dislocation-interface interactions into the well-defined behavior of single crystals. Despite the widespread study of metal plasticity, this aspect is not well understood for simple loading conditions, let alone extreme ones. Our experimental approach includes determining the high-strain rate response as a function of strain and temperature with …
Date: January 5, 2004
Creator: Robertson, I. M.; Beaudoin, A. & Lambros, J.
Object Type: Report
System: The UNT Digital Library
Deterrence and National Security in the Face of an Amorphous Threat (open access)

Deterrence and National Security in the Face of an Amorphous Threat

The National Security threats that we face today and, in turn, the National Security . requirements, are more diverse and complex than they were during the Cold-War from 1945-1990. During that period, and bolstered by the experiences of World Wars I and II, US National Security policy was focused on the stabilization of post WW II country boundaries and containment of the Soviet block and China. The result was the bipolar world in which the nuclear and conventional forces of the United States, the Soviet Union, and their respective allies ensured a measure of political stability through a military stalemate of world wide proportions. The practical result was that large scale changes in national borders were unlikely, but internal conflict within countries, and local conflicts between neighboring countries could still occur, albeit with participation from one or both of the Superpower camps. US National Security Policy was designed primarily for stabilization of the bipolar world on the military front and for competition with the Soviet Union and China on economic and political fronts. The collapse of the Soviet Union changed the global picture. The bipolar world and its military stalemate appear to be gone for the moment and the threat …
Date: January 5, 2001
Creator: Werne, R
Object Type: Report
System: The UNT Digital Library
Development and Application of a Paleomagnetic/Geochemical Method for Constraining the Timing of Burial Diagenetic Events (open access)

Development and Application of a Paleomagnetic/Geochemical Method for Constraining the Timing of Burial Diagenetic Events

Studies of diagenesis caused by fluid migration or other events are commonly hindered by a lack of temporal control. Our results to date demonstrate that a paleomagnetic/geochemical approach can be used to date fluid migration as well as burial diagenetic events. Our principal working hypothesis is that burial diagenetic processes (e.g., maturation of organic-rich sediments and clay diagenesis) and the migration of fluids can trigger the authigenesis of magnetic mineral phases. The ages of these events can be constrained by comparing chemical remanent magnetizations (CRMs) to independently established Apparent Polar Wander Paths. Whilst geochemical (e.g. stable isotope and organic analyses) and petrographic studies provide important clues for establishing these relationships, the ultimate test of this hypothesis requires the application of independent dating methods to verify the paleomagnetic ages. Towards this end, we have used K-Ar dating of illitization as an alternative method for constraining the ages of magnetic mineral phases in our field areas. We have made significant progress toward understanding the origin and timing of chemical remagnetization related to burial diagenetic processes. For example, a recently completed field study documents a relationship between remagnetization and the maturation of organic matter (Blumstein et al., 2004). We have tested the hypothesized …
Date: January 5, 2006
Creator: Elmore, Richard D. & Engel, Michael H.
Object Type: Report
System: The UNT Digital Library
Development of simulation tools for virus shell assembly. Final report (open access)

Development of simulation tools for virus shell assembly. Final report

Prof. Berger's major areas of research have been in applying computational and mathematical techniques to problems in biology, and more specifically to problems in protein folding and genomics. Significant progress has been made in the following areas relating to virus shell assembly: development has been progressing on a second-generation self-assembly simulator which provides a more versatile and physically realistic model of assembly; simulations are being developed and applied to a variety of problems in virus assembly; and collaborative efforts have continued with experimental biologists to verify and inspire the local rules theory and the simulator. The group has also worked on applications of the techniques developed here to other self-assembling structures in the material and biological sciences. Some of this work has been conducted in conjunction with Dr. Sorin Istrail when he was at Sandia National Labs.
Date: January 5, 2001
Creator: Berger, Bonnie
Object Type: Report
System: The UNT Digital Library
Discovery of a new 2.3 s isomer in the neutron-rich nucleus 174Tm (open access)

Discovery of a new 2.3 s isomer in the neutron-rich nucleus 174Tm

None
Date: January 5, 2005
Creator: Chakrawarthy, R. S.; Walker, P. M.; Smith, M. B.; Andreyev, A. N.; Ashley, S. F.; Ball, G. C. et al.
Object Type: Article
System: The UNT Digital Library
Discovery of Ultra-Compact Dwarf Galaxies in the Virgo Cluster (open access)

Discovery of Ultra-Compact Dwarf Galaxies in the Virgo Cluster

The authors have discovered nine ultra-compact dwarf galaxies (UCDs) in the Virgo Cluster, extending samples of these objects outside the Fornax Cluster. Using the 2dF multi-fiber spectrograph on the Anglo-Australian Telescope, the new Virgo members were found among 1500 color-selected, star-like targets with 16.0 < b{sub j} < 20.2 in a two-degree diameter field centered on M87 (NGC4486). The newly-found UCDs are comparable to the UCDs in the Fornax Cluster, with sizes {approx} 100 pc, -12.9 < M{sub B} < -10.7, and exhibiting red, absorption-line spectra, indicative of an older stellar population. The properties of these objects remain consistent with the tidal threshing model for the origin of UCDs from the surviving nuclei of nucleated dwarf ellipticals disrupted in the cluster core. The discovery that UCDs exist in Virgo shows that this galaxy type is probably a ubiquitous phenomenon in clusters of galaxies; coupled with their possible origin by tidal threshing, the UCD population is a potential indicator and probe of the formation history of a given cluster. They also describe one additional bright UCD with M{sub B} = -12.0 in the core of the Fornax Cluster. They find no further UCDs in our Fornax Cluster Spectroscopic Survey down to …
Date: January 5, 2006
Creator: Jones, J.; Drinkwater, M.; Jurek, R.; Phillips, S.; Gregg, M.; Bekki, K. et al.
Object Type: Article
System: The UNT Digital Library
DOE PLANT-WIDE ENERGY ASSESSMENT RESULTS RELATED TO THE U. S. AUTOMOTIVE INDUSTRY (open access)

DOE PLANT-WIDE ENERGY ASSESSMENT RESULTS RELATED TO THE U. S. AUTOMOTIVE INDUSTRY

Forty-nine plant-wide energy efficiency assessments have been undertaken under sponsorship of the U.S. Department of Industrial Technologies Program. Plant-wide assessments are comprehensive, systematic investigations of plant energy efficiency, including plant utility systems and process operations. Assessments in industrial facilities have highlighted opportunities for implementing best practices in industrial energy management, including the adoption of new, energy-efficient technologies and process and equipment improvements. Total annual savings opportunities of $201 million have been identified from the 40 completed assessments. Many of the participating industrial plants have implemented efficiency-improvement projects and already have realized total cost savings of more than $81 million annually. This paper provides an overview of the assessment efforts undertaken and presents a summary of the major energy and cost savings identified to date. The paper also discusses specific results from assessments conducted at four plants in the automotive manufacturing operations and supporting industries. These particular assessments were conducted at facilities that produce engine castings, plastic films used for glass laminates, forged components, and at a body spray painting plant.
Date: January 5, 2006
Creator: Kelly Kissock, Arvind Thekdi, Len Bishop
Object Type: Report
System: The UNT Digital Library
Durability Testing of Antireflection Coatings for Solar Applications (open access)

Durability Testing of Antireflection Coatings for Solar Applications

Antireflection (AR) coatings can be incorporated into highly transmitting glazings that, depending on their cost, performance, and durability of optical properties, can be economically viable in solar collectors, agricultural greenhouses, and PV systems. A number of AR-coated glazings have been prepared under the auspices of the International Energy Agency (IEA) Working Group on Durability of Materials for Solar Thermal Collectors. The AR coatings are of two types, including (1) various sol-gels applied to glass and (2) an embossed treatment of sheet acrylic. Typically, for unweathered glazings, a 4%--5% increase in solar-weighted transmittance has been achieved. For AR-coated glass, reflectance values as low as 0.5%--0.7% at selected wavelengths (680--720 nm) were obtained. To determine the durability of the hemispherical transmittance, several collaborating countries are testing these materials both outdoors and in accelerated weathering chambers. All materials exposed outdoors are affixed to mini-collector boxes to simulate flat-plate collector conditions. Results for candidate AR coatings weathered at geographically disperse outdoor test sites exhibit changes in spectral transmittance primarily in the high visible range (600--700 nm). Accelerated testing at measured levels of simulated solar irradiance and at different constant levels of temperature and relative humidity have been performed in different countries. Parallel testing with …
Date: January 5, 2000
Creator: Jorgensen, G.; Brunold, S.; Koehl, M.; Nostell, P.; Roos, A. & Oversloot, H.
Object Type: Article
System: The UNT Digital Library
Effect of the environment and alloy composition on the electrochemical behavior of Ni-Cr-Mo Alloys (open access)

Effect of the environment and alloy composition on the electrochemical behavior of Ni-Cr-Mo Alloys

Alloy 22 (UNS N06022) is the candidate material for the corrosion resistant, outer barrier of the Yucca Mountain nuclear waste containers. One of the potential corrosion degradation modes of the container is uniform or passive corrosion. Therefore it is of importance to understand the stability of the oxide film, which will control the passive corrosion rate of Alloy 22. Many variables such as temperature, composition and pH of the electrolyte, applied potential, and microstructure and composition of the base metal would determine the thickness and composition of the oxide film. The purpose of this research work was to use electrochemical and surface analysis techniques to explore the influence of solution pH and applied potential on the characteristics of the oxide film formed on Alloy 22 and two experimental alloys containing differing amounts of chromium (Cr) and molybdenum (Mo). Results confirm that bulk metal composition is fundamental to the passive behavior and potential breakdown of the studied alloys. In these preliminary results, welded and non-welded Alloy 22 did not show differences in their anodic behavior.
Date: January 5, 2004
Creator: Hayes, J R; Szmodis, A W; Anderson, K L & Orme, C A
Object Type: Article
System: The UNT Digital Library