Lectures on numerical weather prediction /

At the head of title: Research report.Includes bibliographic references (pages 97-99).Mode of access: Internet

A preliminary evaluation of the Cricketsonde rocket system /

Research supported by the Aerospace Instrumentation Laboratory, Air Force Cambridge Research Laboratories, Office of Aerospace Research, United States Air Force, L.G. Hanscom Field, Massachusetts.Aerospace Instrumentation Laboratory Project 6682.AD0603592 (from http://www.dtic.mil)."June 1964."Includes bibliographical references (page XX).Mode of access: Internet

UHF and microwave frequency acoustic surface wave delay lines : design /

Small, lightweight, reliable, low cost acoustic surface wave delay lines are particularly useful in a variety of military applications including electronic sensing and communications. The purpose of the report is to provide detailed comprehensive procedures and theories for the optimum design of UHF and microwave frequency acoustic surface wave delay lines consisting of two identical, periodic, uniform width, interdigital transducers. The circuit model used to characterize device performance as a function of frequency includes a lossy tuning inductor, finite resistivity transducer fingers, and parasitic shunt capacitance. Surface wave propagation loss is also included. (Modified author abstract).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field, Bedford, Massachusetts.Microwave Physics Laboratory Project 5635.AD0775984 (from http://www.dtic.mil)."16 August 1973."Includes bibliographical references (pages 85-87).Small, lightweight, reliable, low cost acoustic surface wave delay lines are particularly useful in a variety of military applications including electronic sensing and communications. The purpose of the report is to provide detailed comprehensive procedures and theories for the optimum design of UHF and microwave frequency acoustic surface wave delay lines consisting of two identical, periodic, uniform width, interdigital transducers. The circuit model used to characterize device performance as a function of frequency includes a lossy tuning inductor, finite resistivity transducer fingers, and parasitic shunt capacitance. Surface wave propagation loss is also included. (Modified author abstract).Mode of access: Internet

High speed parallel adders and multipliers /

The report contains descriptions, discussions and comparisons of several types of parallel adders and a class of parallel multipliers. It brings together for a comprehensive view the works of many authors, using common terms as much as possible to facilitate comparison. (Author).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field. Bedford, Massachusetts.Data Sciences Laboratory Project 4641.AD0744060 (from http://www.dtic.mil)."31 March 1972."Includes bibliographical references (page 35).The report contains descriptions, discussions and comparisons of several types of parallel adders and a class of parallel multipliers. It brings together for a comprehensive view the works of many authors, using common terms as much as possible to facilitate comparison. (Author).Mode of access: Internet

Microstrip plasma probe /

The report describes a new diagnostic tool-the microstrip plasma probe-which can be used in the laboratory or in a flight payload with little modification. It is rugged in construction, simple in geometric shape, small in frequency operation and low in power requirements. Since the probe is flush mounted and nonradiating, its analytic capability depends on the modification of its electric fringing fields by the outside medium. A measure of standard parameters--that is, reflection coefficient and insertion loss of the probe-can be related back through a series of equations to the parameters of the disturbing medium. Two general models are presented; one with a lossless center conductor, and one with a lossy center conductor. Where possible, theory and experiment are compared. The results are close. A calibration procedure for both models is described. (Author).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field, Bedford, Massachusetts.Microwave Physics Laboratory Project 4642.AD0749860 (from http://www.dtic.mil)."17 July 1972."Includes bibliographical references (pages 27-28).The report describes a new diagnostic tool-the microstrip plasma probe-which can be used in the laboratory or in a flight payload with little modification. It is rugged in construction, simple in geometric shape, small in frequency operation and low in power requirements. Since the probe is flush mounted and nonradiating, its analytic capability depends on the modification of its electric fringing fields by the outside medium. A measure of standard parameters--that is, reflection coefficient and insertion loss of the probe-can be related back through a series of equations to the parameters of the disturbing medium. Two general models are presented; one with a lossless center conductor, and one with a lossy center conductor. Where possible, theory and experiment are compared. The results are close. A calibration procedure for both models is described. (Author).Mode of access: Internet

Array techniques for limited scan application /

A variety of techniques are described which allow the use of large array elements or sub-arrays for limited scan application. Some of these techniques are new and so are described in sufficient detail to predict their performance. Emphasis is placed mainly on the method called odd-mode-scanning; the treatment of other techniques are included to add background for evaluating this new method. (Author).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field, Bedford, Massachusetts.Microwave Physics Laboratory Project 4600.AD0751274 (from http://www.dtic.mil)."19 July 1972."Includes bibliographical references (page 53).A variety of techniques are described which allow the use of large array elements or sub-arrays for limited scan application. Some of these techniques are new and so are described in sufficient detail to predict their performance. Emphasis is placed mainly on the method called odd-mode-scanning; the treatment of other techniques are included to add background for evaluating this new method. (Author).Mode of access: Internet

Some classes of optimal self-dual codes /

Procedures are given for deriving optimal self-dual codes by appending coordinates to Reed-Solomon codes and by direct orthogonalization of Reed-Solomon codes. A possible procedure for searching for self-dual codes is given. (Author).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field, Bedford, Massachusetts.Data Sciences Laboratory Project 5628.AD0744069 (from http://www.dtic.mil)."14 March 1972."Includes bibliographical references (page 21).Procedures are given for deriving optimal self-dual codes by appending coordinates to Reed-Solomon codes and by direct orthogonalization of Reed-Solomon codes. A possible procedure for searching for self-dual codes is given. (Author).Mode of access: Internet

The expansion of electromagnetic fields and potentials in the wave functions of the photon : the exact electromagnetic matrix elements and selection rules for hydrogenic atoms /

The expansion of the unquantized electromagnetic fields and vector and scalar potentials in terms of the wave functions of the relativistic photon is reviewed and extended. Both linear and angular momentum bases are used for the photon wave functions. After second quantizing the electromagnetic field, the results are applied to the obtaining of the exact matrix elements (that is, with retardation taken into account exactly) and selection rules for the emission of photons by hydrogenic atoms. The dichotomy between the photon and wave picture of electromagnetic radiation is discussed and resolved. Furthermore, the most general vector and scaler potentials are obtained through the use of the eigenfunctions of the curl operator. (Author).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field, Bedford, Massachusetts.Aeronomy Laboratory Project 7635.AD0745304 (from http://www.dtic.mil)."27 April 1972."Includes bibliographical references (page XX).Includes bibliographical references (pages 37-38).The expansion of the unquantized electromagnetic fields and vector and scalar potentials in terms of the wave functions of the relativistic photon is reviewed and extended. Both linear and angular momentum bases are used for the photon wave functions. After second quantizing the electromagnetic field, the results are applied to the obtaining of the exact matrix elements (that is, with retardation taken into account exactly) and selection rules for the emission of photons by hydrogenic atoms. The dichotomy between the photon and wave picture of electromagnetic radiation is discussed and resolved. Furthermore, the most general vector and scaler potentials are obtained through the use of the eigenfunctions of the curl operator. (Author).Mode of access: Internet

On the foundations of crystal optics : Part 1. Dispersion theory, Part 2. Theory of reflection and refraction /

The reports investigates the propagation of light in the visible region through a crystalline medium. In Part I, the objective is to determine if the anisotropic arrangement of ordinary (isotropic) dipoles at the nodal points of an orthorhombic lattice would account for the existence of double refraction. Some features of the traditional 'theory of dispersion' are disclosed and clarified. In part II, a crystalline medium is considered as filling a half- space and having a plane boundary at z=0. A plane optical wave is incident on this medium. Because of the linearity of the equations it has to be superimposed on the field originating in the crystal. It is shown that this incident optical wave is actually prevented from entering the crystal because of the modification produced in the field of the crystal by the introduction of a boundary. Material Added 1970. The conclusion that the incident optical field cannot penetrate the crystal boundary, together with a similar conclusion in a paper by Oseen, is the basis of the Ewald-Oseen Extinction Theorem.Part 2 - Theory of Reflection and Refraction translated by Dr. Lowell Hollingsworth from Annalen der Physik, v. 49, 1916, No. 2.Part 1 - Dispersion Theory translated by Dr. Lowell Hollingsworth from Annalen der Physik, v. 49, 1915, No. 1.AD0717697 (from http://www.dtic.mil)."26 August 1970."Part 2. Theory of Reflection and Refraction. pp. 49-84.Part 1. Dispersion theory. pp. 7-48.The reports investigates the propagation of light in the visible region through a crystalline medium. In Part I, the objective is to determine if the anisotropic arrangement of ordinary (isotropic) dipoles at the nodal points of an orthorhombic lattice would account for the existence of double refraction. Some features of the traditional 'theory of dispersion' are disclosed and clarified. In part II, a crystalline medium is considered as filling a half- space and having a plane boundary at z=0. A plane optical wave is incident on this medium. Because of the linearity of the equations it has to be superimposed on the field originating in the crystal. It is shown that this incident optical wave is actually prevented from entering the crystal because of the modification produced in the field of the crystal by the introduction of a boundary. Material Added 1970. The conclusion that the incident optical field cannot penetrate the crystal boundary, together with a similar conclusion in a paper by Oseen, is the basis of the Ewald-Oseen Extinction Theorem.Mode of access: Internet

X-Ray topographic observations of slip distributions in alpha silicon carbide /

An x-ray topographic study is made of three hexagonal SiC crystals, type 6H, of different national origin. All three crystals exhibit a high density of dislocations, many originating at the nucleation edge of the crystal and fanning out to the crystal boundaries. Burgers vectors were identified. Slip in the (1,1,-2,0) direction, characteristic of hexagonal materials, was observed. (Author).Research supported by the Air Force Cambridge Research Laboratories, Air Force Systems Command, United States Air Force, L.G. Hanscom Field, Bedford, Massachusetts.Solid State Sciences Laboratory Project 5620.AD0744076 (from http://www.dtic.mil)."30 March 1972."Includes bibliographical references (page 13).An x-ray topographic study is made of three hexagonal SiC crystals, type 6H, of different national origin. All three crystals exhibit a high density of dislocations, many originating at the nucleation edge of the crystal and fanning out to the crystal boundaries. Burgers vectors were identified. Slip in the (1,1,-2,0) direction, characteristic of hexagonal materials, was observed. (Author).Mode of access: Internet