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Analysis of pipeline steel corrosion data from NBS (NIST) studies conducted between 1922-1940 and relevance to pipeline management.
No full textBetween 1911 and 1984, the National Bureau of Standards (NBS) conducted a large number of corrosion studies that included the measurement of corrosion damage to samples exposed to real-world environments. One of these studies was an investigation conducted between 1922 and 1940 into the corrosion of bare steel and wrought iron pipes buried underground at 47 different sites representing different soil types across the Unites States. At the start of this study, very little was known about the corrosion of ferrous alloys underground. The objectives of this study were to determine (i) if coatings would be required to prevent corrosion, and (ii) if soil properties could be used to predict corrosion and determine when coatings would be required. While this study determined very quickly that coatings would be required for some soils, it found that the results were so divergent that even generalities based on this data must be drawn with care. The investigators concluded that so many diverse factors influence corrosion rates underground that planning of proper tests and interpretation of the results were matters of considerable difficulty and that quantitative interpretations or extrapolations could be done ""only in approximate fashion"" and attempted only in the ""restricted area"" of the tests until more complete information is available. Following the passage of the Pipeline Safety Improvement Act in 2002 and at the urging of the pipeline industry, the Office of Pipeline Safety of the U. S. Department of Transportation approached the National Institute of Standards and Technology (NBS became NIST in 1988) and requested that the data from this study be reexamined to determine if the information handling and analysis capabilities of modern computers and software could enable the extraction of more meaningful information from these data. This report is a summary of the resulting investigations. The data from the original NBS studies were analyzed using a variety of commercially available software packages for statistical analysis. The emphasis was on identifying trends in the data that could be later exploited in the development of an empirical model for predicting the range of expected corrosion behavior for any given set of soil chemistry and conditions. A large number of issues were identified with this corrosion dataset, but given the limited knowledge of corrosion and statistical analysis at the time the study was conducted, these shortcomings are not surprising and many of these were recognized by the investigators before the study was concluded. However, it is important to keep in mind that complete soil data is provided for less than half of the sites in this study. In agreement with the initial study, it was concluded that any differences in the corrosion behavior of the alloys could not be resolved due to the scatter in the results from the environmental factors and no significant difference could be determined between alloys. Linear regression and curve fitting of the corrosion damage measurements against the measured soil composition and properties found some weak trends. These trends improved with multiple regression, and empirical equations representing the performance of the samples in the tests were developed with uncertainty estimates. The uncertainties in these empirical models for the corrosion data were large, and extrapolation beyond the parameter space or exposure times of these experiments will create additional uncertainties. It is concluded that equations for the estimation of corrosion damage distributions and rates can be developed from these data, but these models will always have relatively large uncertainties that will limit their utility. These uncertainties result from the scatter in the measurements due to annual, seasonal, and sample position dependent variations at the burial sites. The data indicate that more complete datasets with soil property measurements reflecting the properties of the soil and ground water directly in contact with the sample from statistically designed experiments would greatly reduce this scatter and enable more representative predictions
Overlap-based cell tracker
No full textIn order to facilitate the extraction of quantitative data from live cell image sets, automated image analysis methods are needed. This paper presents an introduction to the general principle of an overlap cell tracking software developed by the National Institute of Standards and Technology (NIST). This cell tracker has the ability to track cells across a set of time lapse images acquired at high rates based on the amount of overlap between cellular regions in consecutive frames. It is designed to be highly flexible, requires little user parameterization, and has a fast execution time
Software assurance using structured assurance case models
No full textSoftware assurance is an important part of the software development process to reduce risks and ensure that the software is dependable and trustworthy. Software defects and weaknesses can often lead to software errors and failures and to exploitation by malicious users. Testing, certification and accreditation have been traditionally used in the software assurance process to attempt to improve software trustworthiness. In this paper, we examine a methodology known as a structured assurance model, which has been widely used for assuring system safety, for its potential application to software assurance. We describe the structured assurance model and examine its application and use for software assurance. We identify strengths and weaknesses of this approach and suggest areas for further investigation and testing
Optical fiber power meter comparison between NIST and NIM*
No full textWe describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and National Institute of Metrology (NIM-China). We report optical fiber-based power measurements at nominal wavelengths of 1310 nm and 1550 nm. We compare the laboratories reference standards by means of a commercial optical power meter. Measurement results showed the largest difference of less than 2.6 parts in 10^3, which is within the combined standard (k = 1) uncertainty for the laboratories reference standards
A gas pressure scale based on primary standard piston gauges
No full textTechnology (NIST) has redefined its gas pressure scale, up to 17 MPa, based on two primary standard piston gauges. The primary standard piston gauges are 35.8 mm in diameter and operate from 20 kPa to 1 MPa. Ten secondary standard piston gauges, two each of five series of the Ruska 2465 type, with successively smaller diameters form the scale extending up to 17 MPa. Six of the piston gauges were directly compared to the primary standards to determine their effective area and expanded (k = 2) uncertainty. Two piston gauges operating to 7 MPa were compared to the 1.4 MPa gauges, and two piston gauges operating to 17 Mpa were compared to the 7 MPa gauges. Distortion in the 7 MPa piston gauges was determined by comparing those gauges to a DH Instruments PG7601 type piston gauge, whose distortion was calculated using elasticity theory. The relative standard uncertainties achieved by the primary standards range from 3.0 106 to 3.2 106. The relative standard uncertainty of the secondary standards is as low as 4.2 106 at 300 kPa. The effective areas and uncertainties were validated by comparison to standards of other National Metrology Institutes (NMIs). Results show agreement in all cases to better than the expanded (k = 2) uncertainty of the difference between NIST and the other NMIs, and in most cases to better than the standard (k = 1) uncertainty of the difference
Gordon Dunn
No full textGordon Dunn
Inducted: 2010
Citation: For his internationally recognized research on electron-ion and -atom collisions critical to the understanding of high temperature plasmas; for his Division-level leadership at NBS and JILA; and for his contributions to the growth of the atomic, molecular, and optical physics community in support of nationally important programs for four decades.
Tenure: 1961-2002
Birth: 1932, Montpelier, Idaho
Education:
University of Washington, BS (Physics), 1953
University of Washington, PhD (Physics), 1961
Positions held:
NRC Postdoctoral Research Fellow, Atomic Physics Division (Boulder), 1961-1962
Research Associate, NBS and JILA (Boulder), 1962-1964
Physicist, NBS/NIST Quantum Physics Division and JILA Fellow (Boulder), 1964-2002
COMSCI Fellow, House Science and Technology Committee, 1975-1976
Chief, Quantum Physics Division, Center for Absolute Physical Quantities (Boulder), 1977-1985
Chairman, JILA (Boulder), 1987-89
Honors:
Lecturer and Professor Adjoint, Department of Physics, University of Colorado (1964-2002)
Fellow, JILA (1964)
US Department of Commerce Gold Medal (1970)
Davisson-Germer Prize, APS (1984)
Visiting Professor, Manne Siegbahn Laboratory, Stockholm University (1996-97)
Fellow, American Physical Society
Fellow, NIST (1994)
Memberships:
American Physical Society
NRC Committee on Atomic, Molecular, and Optical Science
Editorial Board, Journal of Physical and Chemical Reference Data (1989-92)
Publications:
More than 160 publications including:
Dunn, G. and Kieffer, L.J., “Electron Impact Ionization Cross Section Data for Atoms, Atomic Ions, and Diatomic Molecules: 1. Experimental Data,” Rev. Mod. Phys. 38, 1 (1966)
Dunn, G., “Anisotropies in Angular Distributions of Molecular Dissociation Products,” Phys. Rev. Lett. 8, 62 (1962)
Dunn, G., Van Zyl, B., and Zare, R., “Dissociation of H2+ by Electron Impact,” Phys. Rev. Lett. 15, 610 (1965)
Dunn, G., Beli?, D. S., Morgan, T.J., Mueller, D.W., and Timmer, C., “Dielectronic Recombination: A crossed beams observation and measurement of cross sections,” Phys. Rev. Lett. 50, 339 (1983)
Dunn, G., Muller, A., Belic, D. S., DePaola, B., Djuric, N., Mueller, D.W., and Timmer, C., “Field Effects on the Rydberg Product State Distribution from Dielectronic Recombination,” Phys. Rev. Lett. 56, 127 (1986)
Dunn, G., Zong, W., Djuric, N., Larsson, M., Greene, C.H., Al-Khalili, A., Neau, A., Derkatch, A.M., Vikor, L., Shi, W., LePadellac, A., Rosen, S., Danared, H., and Af Ugglas, M., “Resonant Ion Pair Formation in Electron Collisions with Ground State Molecular Ions,” Phys. Rev. Lett. 83, 951 (1999
Evaluation of the propensity of niobium to absorb hydrogen during fabrication of superconducting radio frequency cavities for particle accelerators
No full textDuring the fabrication of niobium superconducting radio frequency (SRF) particle accelerator cavities procedures are used that chemically or mechanically remove the passivating surface film of niobium pentoxide (Nb2O5). Removal of this film will expose the underlying niobium metal and allow it to react with the processing environment. If these reactions produce hydrogen at sufficient concentrations and rates, then hydrogen will be absorbed and diffuse into the metal. High hydrogen activities could result in supersaturation and the nucleation of hydride phases. If the metal repassivates at the conclusion of the processing step and the passive film blocks hydrogen egress, then the absorbed hydrogen or hydrides could be retained and alter the performance of the metal during subsequent processing steps or in-service. This report examines the feasibility of this hypothesis by first identifying the postulated events, conditions, and reactions and then determining if each is consistent with accepted scientific principles, literature, and data. Established precedent for similar events in other systems was found in the scientific literature and thermodynamic analysis found that the postulated reactions were not only energetically favorable, but produced large driving forces. The hydrogen activity or fugacity required for the reactions to be at equilibrium was determined to indicate the propensity for hydrogen evolution, absorption, and hydride nucleation. The influence of processing conditions and kinetics on the proximity of hydrogen surface coverage to these theoretical values is discussed. This examination found that the hypothesis of hydrogen absorption during SRF processing is consistent with published scientific literature and thermodynamic principles
Melville S. Green
No full textMELVILLE S. GREEN
Inducted: 2010
Citation:
For securing for NBS an international reputation in the field of statistical physics
Tenure: 1954-1968
Birth: 1922, Queens, New York
Death: 1979
Education:
Columbia College, BA (Physics), 1944
Princeton University, MA (Physics), 1947
Princeton University, PhD (Physics), 1951
Positions held:
Physicist, Thermodynamics Section, Heat and Power Division, Lab 3, 1954-1958
Chief, Statistical Physics Section, Heat Division, Institute for Basic Standards, 1960-1968
Honors:
Fulbright Travel Grant (1957-1958)
J.S. Guggenheim Fellowship Award (1957-1958)
US Department of Commerce Gold Medal for Distinguished Achievement in Federal Service (1965)
Portrayed in the American Physical Society Centennial’s Photo Gallery of 50 most famous scientists in the history of statistical and nonlinear physics (1999)
Memberships:
Fellow, American Physical Society
Member, Washington Academy of Sciences
Member, Washington Philosophical Society
Member of the Board of Editors:
Journal of Mathematical Physics (1963-65)
Physical Review (1964-1966)
Journal of Physics of Fluids (1966-69)
Publications:
More than 65 publications including:
Green, M.S., “Boltzmann Equation from the Statistical Mechanical Point of View”, J. Chem. Phys. 25, 836 (1956)
Green, M.S. and Piccirelli, R.A., “Basis of the Functional Assumption in the Theory of the Boltzmann Equation”, Phys. Rev. 132, 1388 (1963)
Green, M.S. and Sengers, J.V., eds., Critical Phenomena, Proceedings of a Conference, NBS Miscellaneous Publ. 273, 242 pp., GPO (1966)
Vicentini, M., Levelt Sengers, J.M.H., and Green, M.S., “Scaling-law Equation of State of Gases in the Critical Region”, Phys. Rev. Letters 18 1113 (1967)
Green, M.S., “Bose-Einstein Condensation and the λ-transition in Liquid Helium”, Phys. Rev. Letters 1, 409 (1958)
Beckett, C.W., Woolley, H.W., and Green, M.S., “Thermochemistry and Thermodynamics of Substances”, Ann. Rev. Phys. Chem. 7 287 (1956
(Audio Part 2 of 3) Oral history interview of John (Jack) Wachtman, February 4, 2010 / with David Lide, Edwin Fuller, Sheldon Wiederhorn and Hans Oser
No full textOral history interview of Dr. John Wachtman, who had an active career in the Material Science area of the NBS, the predecessor of NIST. Dr. Wachtman first joined NBS as a bench scientist. Dr. Wachtman spent thirty-two years at NIST starting in 1951
Memoir of John B. "Jack" Wachtman
No full textOral history interview of Dr. John Wachtman, who had an active career in the Material Science area of the NBS, the predecessor of NIST. Dr. Wachtman first joined NBS as a bench scientist. Dr. Wachtman spent thirty-two years at NIST starting in 1951