On the Statistical Theory of Electromagnetic Waves in a Fluctuating Medium (II): Mathematical Basis of the Analogies to Quantum Field Theory (open access)

On the Statistical Theory of Electromagnetic Waves in a Fluctuating Medium (II): Mathematical Basis of the Analogies to Quantum Field Theory

Report discussing the relationship between quantum field theory and the the statistical theory of waves. Basic equations exist in the latter theory which correspond closely to the fundamental equations of the former theory; i.e., to the commutation relations and the Heisenberg equation of motion. A probability density function of waves is introduced here which corresponds to the probability amplitude function in quantum mechanics. The theory of the statistical Green's functions and their relationships to the expectation values of the physical variables is also extensively developed. It is found that there exists a one-to-one correspondence between the formalism of Green's functions presented here and that used in field theory.
Date: December 7, 1964
Creator: Furutsu, K.
System: The UNT Digital Library
Refractive Indices and Densities of Aqueous Solutions of Invert Sugar (open access)

Refractive Indices and Densities of Aqueous Solutions of Invert Sugar

Report of the refractive indices and densities of aqueous solutions of invert sugar at temperatures of 15, 20, 25, and 30º C, for concentrations up to about 82 percent of invert sugar (by weight). From the results, equations have been derived which relate the refractive index and percent of invert sugar (weight in air) at each temperature. Other equations relate the absolute density and percent of invert sugar (weight in vacuum) at each temperature. Five-decimal tables giving the refractive indices and densities of invert sugar solutions containing 1 to 85 percent of sugar are given for each percentage of invert sugar at the four temperatures.
Date: June 7, 1963
Creator: Snyder, Carl F. & Hattenburg, Albert T.
System: The UNT Digital Library
Reduction of Data for Piston Gage Pressure Measurements (open access)

Reduction of Data for Piston Gage Pressure Measurements

Report discussing pressure measurements made with piston gages that are affected by gravity, temperature, pressure, and several other variables. For accurate determinations of pressure the calculations must take these variables into account. A general equation is developed and simplified procedures for calculating pressure are illustrated.
Date: June 17, 1963
Creator: Cross, J. L.
System: The UNT Digital Library
Compilation of the Melting Points of the Metal Oxides (open access)

Compilation of the Melting Points of the Metal Oxides

Report compiling the melting points of 70 metal oxides published prior to January 1963. Both the original melting point and the equivalent value based on the International Practical Temperature Scale of 1948 are presented. Included in the survey is information on pertinent experimental details such as the method of temperature measurement, purity, furnace type, and environmental conditions.
Date: October 10, 1963
Creator: Schneider, Samuel J.
System: The UNT Digital Library
New Description of Thorium Spectra (open access)

New Description of Thorium Spectra

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
System: The UNT Digital Library
Atomic Energy Levels in Crystals (open access)

Atomic Energy Levels in Crystals

Report discussing discrete energy levels observed within certain crystals which are due to perturbations of energy levels of the free ion by an electrostatic field arising from the crystal lattice. The analytic procedures for determining the field from the charge configuration are given, and the resulting fields are classified according to their symmetry. After a general survey of group-theoretical ideas, the applicable groups are analyzed in detail, and characters appropriate for both integral and half-integral angular momenta of the free ion are tabulated. Text includes tabulations, equations, and matrices using Wigner and Racah coefficients.
Date: February 24, 1961
Creator: Prather, John L.
System: The UNT Digital Library
Temperature-Induced Stresses in Solids of Elementary Shape (open access)

Temperature-Induced Stresses in Solids of Elementary Shape

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.
System: The UNT Digital Library
Specific Heats and Enthalpies of Technical Solids at Low Temperatures: A Compilation from the Literature (open access)

Specific Heats and Enthalpies of Technical Solids at Low Temperatures: A Compilation from the Literature

Report giving tables of the specific heat, cp, and the enthalpy of 28 metals, 3 alloys, 8 other inorganic substances, and 8 organic substances in the temperature range, 1º to 300º K.
Date: October 3, 1960
Creator: Corruccini, Robert J. & Gniewek, John J.
System: The UNT Digital Library
A Spectrophotometric Atlas of the Spectrum of CH from 3000A to 5000A (open access)

A Spectrophotometric Atlas of the Spectrum of CH from 3000A to 5000A

Report of the near ultraviolet and visible emission spectrum of CH presented in the form of a spectrophotometric atlas. The spectrum was recorded photoelectrically from an acetylene-oxygen flame in the region 4900 to 3000 A by use of a high-resolution grating monochromator. Each of the lines in the CH spectrum is identified.
Date: February 14, 1961
Creator: Bass, Arnold M. & Broida, H. P.
System: The UNT Digital Library
Vibration-Rotation Structure in Absorption Bands for the Calibration of Spectrometers From 2 to 16 Microns (open access)

Vibration-Rotation Structure in Absorption Bands for the Calibration of Spectrometers From 2 to 16 Microns

Reports discussing bands of common gases that have been tabulated and remeasured wherever necessary from 2 to 16 microns to obtain an accuracy of about 0.03 cm-1 throughout the region and to provide good calibrating points at frequent intervals. Some 600 rotation-vibration lines are illustrated in 20 spectrograms and wavenumbers are listed in companion tables with considerable intercomparison with worthy data obtained in other laboratories. The absorption bands were remeasured or calibrated by using either a precisely graduated grating circle or standard atomic lines with the fringe system formed by a Fabry-Perot interferometer. Characteristic features of the individual bands are discussed briefly and references to other publications are given. The substances used for calibration include H2O, CO2, CO, HCl, HBr, NH3, C2H2, CH4, N2O, and polystyrene film.
Date: June 21, 1960
Creator: Plyler, Earle K.; Danti, Alfred; Blaine, L. R. & Tidwell, E. D.
System: The UNT Digital Library
Radio Meteorology (open access)

Radio Meteorology

Report compiling the work done in radio meteorology over the past ten years at the National Bureau of Standards' Central Radio Propagation Laboratory (CRPL). There is an emphasis upon the effects of the lower atmosphere on the propagation of radio waves. The CRPL group has concentrated upon the refraction of radio waves as well as the refractive index structure of the lower atmosphere on both synoptic and climatic scales. Additional chapters on radio-meteorological parameters and the absorption of radio waves by the various constituents of the lower atmosphere.
Date: March 1, 1966
Creator: Bean, B. R. & Dutton, E. J.
System: The UNT Digital Library
Microwave Attenuation Standards and Measurements (open access)

Microwave Attenuation Standards and Measurements

Report discussing microwave attenuation measurement methods and standards. In addition, a relatively new and more precise way of representing and analyzing an attenuation measurement is presented. This in turn permits more rigorous definitions and error analyses than were previously possible. The referral of microwave attenuation measurements to standards operating at lower frequencies is discussed with particular attention to the errors in the referral processes as well as the errors in the standards themselves. Desirable characteristics are listed for attenuators which are suitable for calibration. Measurement methods are classified and described. Comments are made on the accuracy and convenience of various methods, and references are given which cover most of the basic and important research in this field. Key words: Microwave, attenuation, measurements, standards, tutorial.
Date: April 3, 1967
Creator: Beatty, Robert W.
System: The UNT Digital Library
Abscissas and Weights for Guassian Quadrature For N=2 to 100, and N-125, 150, 175, 200 (open access)

Abscissas and Weights for Guassian Quadrature For N=2 to 100, and N-125, 150, 175, 200

The abscissas and weights for Gaussian Quadrature of order N = 2 to 100,and N = 125, 150, 175, and 200 are given. The abscissas are given to twenty-four places and the error is estimated to be no more than 1 unit in the last place. The weights are given to twenty-three places and the error is estimated to be no more than 1 unit in the last place.
Date: December 28, 1966
Creator: Love, Carl H.
System: The UNT Digital Library
Microwave Impedance Measurements and Standards (open access)

Microwave Impedance Measurements and Standards

Report presenting a survey and discussion of well-known microwave impedance measurement techniques. The discussion includes an introduction which emphasizes basic concepts and reflection coefficient-voltage standing-wave ratio relationships. Sources of error in the various measurement techniques are discussed and methods to reduce errors are presented. Methods using rotating loops and resonance lines are included and a brief discussion of microwave impedance standards is given.
Date: August 12, 1965
Creator: Beatty, Robert W.
System: The UNT Digital Library
A Study of Lunar Surface Radio Communication (open access)

A Study of Lunar Surface Radio Communication

Report discussing the problem of point-to-point radio communication on the moon. Equations and curves are presented to estimate power requirements in lunar communication systems. Consideration is given to ground wave attenuation over both layered and non-layered grounds, antenna ground losses in situations where ground screens are impractical, noise level estimates in the receiving system, and the effects on propagation of possible lunar ionospheres. An example of the calculation of required power for a particular communication system is given, and further studies are suggested.
Date: September 14, 1964
Creator: Vogler, L. E.
System: The UNT Digital Library
Oxidation of Polycyclic, Aromatic, Hydrocarbons: A Review of the Literature (open access)

Oxidation of Polycyclic, Aromatic, Hydrocarbons: A Review of the Literature

Report discussing the literature on the oxidation of polycyclic, aromatic hydrocarbons. Information has been assembled on (1) the oxidants effective in the oxidation of such hydrocarbons, (2) the relative reactivity of the hydrocarbons, (3) the conditions under which oxidation proceeds, (4) the chemical mechanisms involved when such oxidations occur, and (5) the products formed.
Date: September 17, 1965
Creator: Tipson, R. Stuart
System: The UNT Digital Library
Calibration of Liquid-in-Glass Thermometers (open access)

Calibration of Liquid-in-Glass Thermometers

Report discussing important elements of thermometer design. Factors affecting the use of common types of liquid-in-glass thermometers are included together with tables of tolerances and reasonably attainable accuracies. The calculation of corrections for the temperature of the emergent stem is given in detail for various types of thermometers and conditions of use.
Date: February 12, 1965
Creator: Swindells, James F.
System: The UNT Digital Library
Automatic Indexing: A State-of-the-Art Report (open access)

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

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
System: The UNT Digital Library
Publications Received in the Library of the National Bureau of Standards, July 1962 (open access)

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

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.
System: The UNT Digital Library
Influence of a Sector Ground Screen on the Field of a Vertical Antenna (open access)

Influence of a Sector Ground Screen on the Field of a Vertical Antenna

Report show the field of a short vertical antenna on a homogeneous ground is modified by the presence of a metallic screen. The screen is taken in the form of a circular disk and a concentric sector. The modification of the field is expressed in the form of surface integrals over the disk and the sector. Extensive numerical results for these basic integrals are given and a number of applications are illustrated.
Date: April 15, 1963
Creator: Wait, James R. & Walters, Lillie C.
System: The UNT Digital Library
Tensile and Impact Properties of Selected Materials From 20 to 300 ºK (open access)

Tensile and Impact Properties of Selected Materials From 20 to 300 ºK

Report giving the tensile and impact properties of structural materials that were experimentally determined at temperatures from 20 to 300 ºK. Tensile properties of a few materials were also determined at 4 ºK. The properties experimentally determined were the yield strength, tensile strength, elongation, and reduction of area, the stress versus strain curve, and the impact energy. The test equipment and procedures are described. The individual data are presented in tables, and the average results are displayed in graphs.
Date: June 28, 1963
Creator: Warren, K. A. & Reed, R. P.
System: The UNT Digital Library
Infrared Spectroscopy of Carbohydrates: A Review of the Literature (open access)

Infrared Spectroscopy of Carbohydrates: A Review of the Literature

Report presenting of survey of the literature on the infrared spectroscopy of carbohydrates in order to assemble and systematize information in this field. Discusses principles and instrumentation, sampling techniques, comparison of samples, and the interpretation of the spectra. In addition, examples are discussed of the use of infrared spectra for qualitative and quantitative purposes and in the determination of structure. Special techniques are briefly described.
Date: June 1968
Creator: Tipson, R. Stuart
System: The UNT Digital Library
An Introduction to the Description and Evaluation of Microwave Systems Using Terminal Invariant Parameters (open access)

An Introduction to the Description and Evaluation of Microwave Systems Using Terminal Invariant Parameters

Report presenting the technical background and basis for a new method of evaluating certain performance parameters which are common to all microwave systems. A unique feature of the new measurement concept is its elimination of the precision waveguide and connector requirements for an important class of measurement problems.
Date: October 1969
Creator: Engen, Glenn F.
System: The UNT Digital Library
Bibliography and Index on Vacuum and Low Pressure Measurement, January 1960 to December 1965 (open access)

Bibliography and Index on Vacuum and Low Pressure Measurement, January 1960 to December 1965

From Abstract: "The bibliography, a supplement to NBS Monograph 35, of the same title, covers the years 1960 to 1965, inclusive, and include 109 references for prior years not listed in Monograph 35. It contains 1787 references, 38 of which are to books. The references, besides those directly concerned with pressure measurement, include those on vacuum technology which may bear on the technique of vacuum measurement, such as on adsorption and desorption, diffusion of gases into solids, gas conductance and hardware such as pumps, seals and traps."
Date: May 31, 1967
Creator: Brombacher, W. G.
System: The UNT Digital Library