524 Matching Results

Search Results

Automatic Indexing: A State-of-the-Art Report

Description: Report presenting a state-of-the-art survey of automatic indexing systems and experiments. It was conducted by the Research Information Center and Advisory Service on Information Processing, Information Technology Division, Institute for Applied Technology, National Bureau of Standards. Consideration is first given to indexes compiled by or with the aid of machines, including citation indexes. Advantages, disadvantages, and possibilities for modification and improvement are discussed. Experiments in automatic assignment indexing are summarized. Related research efforts in such areas as automatic classification and categorization, computer use of thesauri, statistical association techniques, and linguistic data processing are described. A major question is that of evaluation, particularly in view of evidence of human inter-indexer inconsistency. It is concluded that indexes based on words extracted from text are practical for many purposes today.
Date: March 30, 1965
Creator: Stevens, Mary Elizabeth
Partner: UNT Libraries Government Documents Department

International Practical Temperature Scale of 1948: Text Revision of 1960

Description: Report is a text revision of the International Temperature Scale of 1948; the numerical values of temperatures remain the same. The adjective "Practical" was added to the name by the International Committee on Weights and Measures. The scale continues to be based upon six fixed and reproducible equilibrium temperatures to which values have been assigned, and upon the same interpolation formulas relating temperatures to the indications of specified measuring instruments. Some changes have been made in the text to make the scale more reproducible than its predecessor. The triple point of water, with the value 0.01 ºC replaces the former ice point as a defining fixed point of the scale. It is also recommended that the zinc point, with the value 419.505 ºC, be used instead of the sulfur point. The recommendations include new information that has become available since 1948.
Date: September 8, 1961
Creator: Stimson, H. F.
Partner: UNT Libraries Government Documents Department

Theory and Methods of Optical Pyrometry

Description: Report reviewing the theoretical methods of optical pyrometry and the application of these methods at the National Bureau of Standards in realizing, maintaining and distributing the International Practical Temperature Scale above 1063 ºC is presented. In the theoretical presentation, the concepts of effective and mean effective wavelengths are introduced, and various equations relating these parameters to each other and other physical quantities are derived. The methods presentation discusses important features of precision visual optical pyrometers, experimental procedures, and results of primary and secondary calibrations of optical pyrometers.
Date: March 1, 1962
Creator: Kostkowski, H. J. & Lee, R. D.
Partner: UNT Libraries Government Documents Department

Bibliography on Atomic Transition Probabilities

Description: Report presenting a bibliography on atomic transition probabilities. The papers are arranged according to elements and stages of ionization, and the method employed and class of transitions are indicated behind each reference. Only articles on discrete transitions, both permitted and forbidden, are listed. Also included is a supplementary list of papers dealing with transition probabilities from a general point of view, a table showing the availability of numerical material on the individual atoms and ions, and a table of conversion factors.
Date: August 1, 1962
Creator: Glennon, B. M. & Wiese, W. L.
Partner: UNT Libraries Government Documents Department

Annotated Bibliography on Soft X-ray Spectroscopy

Description: Report presenting a bibliography of about 550 references of the soft X-ray literature since 1950 and through 1960. The emphasis is on the application of soft X-ray spectroscopy to the study of valence band electronic states in metals and alloys. Therefore, the spectral region of 25 to 800 angstroms involving ruled glass grating spectrometers is of principal interest. In addition to soft X-ray data, references on all pertinent aspects of the apparatus and experimental problems are included. Also listed separately are references of value in corroborating soft X-ray data with other results. Subject, author, X-ray band, material, and other indices are included.
Date: June 29, 1962
Creator: Yakowitz, Harvey, 1939- & Cuthill, J. R.
Partner: UNT Libraries Government Documents Department

Analytical Standards for Trace Elements in Petroleum Products

Description: Report discussing a search conducted for stable, oil-soluble, organic compounds of metals (and other elements) for use in the spectrographic analysis of petroleum products. Compounds having suitable physical properties have been selected as standards. Methods are given for preparation of the compounds and for the spectrographic and chemical analysis of the chosen standards. Procedures are described for the preparation of stable solutions thereof in petroleum oils.
Date: October 1, 1962
Creator: Isbell, H. S.; Tipson, R. Stuart; Hague, J. L.; Scribner, B. F.; Smith, W. Harold; Wade, Clarence W. R. et al.
Partner: UNT Libraries Government Documents Department

Geometrical Considerations and Nomenclature for Reflectance

Description: Report presenting a unified approach to the specification of reflectance, in terms of both incident- and reflected- beam geometry. Nomenclature to facilitate this approach is proposed. Nomenclature for categorizing and specifying reflectance quantities for a variety of different beam configurations (both incident and reflected beams) is described, and all are defined and interrelated in terms of the bidirectional reflectance-distribution function. The conditions under which the formalism can be applied, including situations involving considerable sub-surface scattering, are carefully established. The entire treatment is limited to the domain of classical geometrical-optics radiometry and does not take into account interference and diffraction phenomena, such as are frequently encountered with highly coherent radiant flux.
Date: October 1977
Creator: Nicodemus, F. E.; Richmond, J. C.; Hsia, J. J.; Ginsberg, I. W. & Limperis, T.
Partner: UNT Libraries Government Documents Department

Measurement Assurance for Gage Blocks

Description: Report discussing the philosophy of measurement assurance and the three levels of measurement assurance programs. The measurement assurance programs are outlined to show how control over the measurement process can be maintained and how the offset (or systematic error) from the unit of length maintained by the National Bureau of Standards ban be made negligible. This monograph is intended for those who need to know on a continuing basis the uncertainty of their gage block calibration procedure.
Date: February 1979
Creator: Croarkin, Carroll; Beers, John & Tucker, Clyde
Partner: UNT Libraries Government Documents Department

Temperature-Induced Stresses in Solids of Elementary Shape

Description: Report discussing how solids subjected to non-uniform temperature change develop internal stresses determined by, (1) the temperature distribution within the solid, and (2) certain physical constants of the material. For two varieties of heating, the equations determining stress have been put in convenient form for practical use, and tables of certain temperature functions show how to determine stresses in a slab, in a cylinder, or in a sphere subjected to either of two modes of heating. The temperature-distribution tables independently provide a useful means for the ready estimation of temperature gradients.
Date: June 21, 1960
Creator: Adams, Leason H. & Waxler, Roy M.
Partner: UNT Libraries Government Documents Department

Evaluating the Impact of Securities Regulation on Venture Capital Markets

Description: Report providing a detailed and analytical assessment of the economic techniques used by researchers to evaluate the efficiency of capital markets. The application of these techniques to that portion of the capital market which supplies venture funds to small, technology-based firms is emphasized. The primary elements of such analysis are the "efficient market ' hypothesis" and the "capital asset pricing model." The empirical analogue of the latter is commonly referred to as the market model."
Date: June 1980
Creator: Barth, James R.; Cordes, Joseph J. & Tassey, Gregory
Partner: UNT Libraries Government Documents Department

New Description of Thorium Spectra

Description: Report discussing wavelengths and estimated intensities in electrodeless lamp and spark sources presented for 15121 lines of ThI, ThII, ThIII, and ThIV in the spectral range from 2000 to 11550 A. Also contains tables of previously published interferometric values.
Date: June 21, 1960
Creator: Zalubas, Romuald
Partner: UNT Libraries Government Documents Department

Bibliography of Temperature Measurement: January 1953 to June 1960

Description: Report presenting more than 500 references to the field of temperature measurement. These references were collected from two general sources: Scientific and technical literature and government reports. The period covered is from 1953 to June 1960, with some from earlier dates. References are divided into a number of categories based on the type of instrument used. Some references to calibration of instruments and to scientific theories upon which temperature measurement is based are also presented.
Date: April 6, 1961
Creator: Halpern, Carl & Moffat, Robert J.
Partner: UNT Libraries Government Documents Department

Publications Received in the Library of the National Bureau of Standards, July 1962

Description: Report providing an alphabetical listing of the periodicals, both American and foreign, that are currently being received in the Washington (D.C.) Library of the National Bureau of Standards. Approximately 2,000 titles are cited, together with call numbers indicating the location of each in the NBS Washington Library. Although this information was compiled primarily for the use of the Bureau's scientific staff, it is also of value to libraries, scientific and technical organizations, and research workers.
Date: November 23, 1962
Creator: Hopper, Natalie J.
Partner: UNT Libraries Government Documents Department

On the Establishment of the Thermodynamic Scale of Temperature by Means of the Constant-Pressure Thermometer

Description: Report issued by the Bureau of Standards over two different types of gas thermometry, with its main focus on the constant-pressure thermometer. The thermodynamic scale of temperature is also discussed. This report includes tables, and illustrations.
Date: 1907
Creator: Buckingham, Edgar
Partner: UNT Libraries Government Documents Department

A New Determination of the Ratio of the Electromagnetic to the Electrostatic Unit of Electricity [Part 1]

Description: Report issued by the Bureau of Standards over new determinations made in regard to units of electricity. Methods and equipment used are discussed. This report includes tables, illustrations, and photographs. Part 1 includes sections I through VI.
Date: 1907
Creator: Rosa, Edward B. & Dorsey, N. E.
Partner: UNT Libraries Government Documents Department

Dependence of Magnetic Hysteresis upon Wave Form

Description: Report issued by the Bureau of Standards over studies on magnetic hysteresis and its dependence upon wave form. Methods and equipment used during the studies are presented and discussed. This report includes tables, and illustrations.
Date: 1909
Creator: Lloyd, Morton G.
Partner: UNT Libraries Government Documents Department

Selective Radiation from the Nernst Glower

Description: Report issued by the Bureau of Standards over studies conducted on the radiation emitted from a Nernst filament. Methods and results of the studies are presented and discussed. This report includes tables, and illustrations.
Date: 1908
Creator: Coblentz, W. W.
Partner: UNT Libraries Government Documents Department

The Testing of Glass Volumetric Apparatus

Description: Report issued by the Bureau of Standards over testing conducted on volumetric glass apparatus. Types of glass apparatus being tested are presented and discussed. The results of the testing are also discussed. This report includes tables, illustrations, and photographs.
Date: 1908
Creator: Osborne, N. S. & Veazey, B. H.
Partner: UNT Libraries Government Documents Department

The Determination of the Constants of Instrument Transformers

Description: Report issued by the Bureau of Standards over studies on instrument transformers. As stated in the first paragraph, "the principle of the method here described is the same for both current and potential transformers, being an application of the potentiometer method" (p. 281). The methods and equipment studied are presented and discussed.
Date: 1911
Creator: Agnew, P. G. & Fitch, T. T.
Partner: UNT Libraries Government Documents Department