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General Relationships Between the Various Systems of Reference Axes Employed in Flight Mechanics

Description: "The different possibilities of orientation of the systems of axes currently employed in flight mechanics are compiled and described. Of the three possible couplings between the wind and aircraft axes, the most suitable coupling is that in which the y axis is made the principal axis of rotation for one of the two coupling angles (angles of attack). In connection with this coupling, an experimental system of axes is introduced, whose axes x(sub e) and z(sub e) are situated in the plane of symmetry of the airplane and rotate about the airplane lateral axis y = y(sub e)" (p. 1).
Date: November 1940
Creator: Rautenberg, H. J.
Partner: UNT Libraries Government Documents Department

Static Longitudinal Stability of a Tandem-Coupled Bomber-Fighter Airplane Configuration Proposed by All American Airways, Inc.

Description: "At the request of the Air Materiel Command an investigation was made in the Langley free-flight tunnel to determine the static longitudinal stability and control characteristics of models coupled together in a tandem configuration proposed by All American Airways, Inc. Force tests were made using 1/20-scale models of B-29 end F-80 airplanes to determine the effects of coupling the fighter to the tail of the bomber. The results of the investigation showed that for the bomber alone the aerodynamic center was 0.21 mean aerodynamic chord behind the center of gravity (stable) but that for the tandem configuration the aerodynamic center was 0.09 mean aerodynamic chord forward of the center of gravity, of the combination (unstable)" (p. 1).
Date: March 14, 1950
Creator: Hewes, Donald E.
Partner: UNT Libraries Government Documents Department

Static Longitudinal Stability of a Tandem-Coupled Bomber-Fighter Airplane Configuration Similar to One Proposed by Douglas Aircraft Company, Inc.

Description: "At the request of the Air Materiel Command, an investigation was made in the Langley free-flight tunnel to determine the longitudinal stability and control characteristics of models coupled together in a tandem configuration for aerial refueling similar to one proposed by the Douglas Aircraft Company, Inc. Static force tests were made with 1/20-scale models of the B-29 and F-80 airplanes to determine the effects of rigidly coupling the airplanes together. The Douglas configuration differs from the rigid configuration tested in that it provides for some freedom in pitch and vertical displacement" (p. 1).
Date: April 28, 1950
Creator: Hewes, Donald E.
Partner: UNT Libraries Government Documents Department

Dynamic Longitudinal Stability and Control of Tandem Coupled Bomber-Fighter Airplane Models With Rigid and Pitch-Free Couplings

Description: Report presenting an investigation in the free-flight tunnel to determine the dynamic longitudinal stability and control characteristics of tandem-coupled bomber-fighter airplane models. Results regarding bomber alone tests, freely coupled combination, and rigidly coupled combination are provided.
Date: January 22, 1951
Creator: Grana, David C. & Hewes, Donald E.
Partner: UNT Libraries Government Documents Department

Simulated Flight Investigation of Scaled-Speed Elastic Sweptwing Bomber and Fighter Models Coupled Wing Tip to Wing Tip

Description: Memorandum presenting a wind-tunnel investigation in which dynamic models that included elastic simulation were used to study the flight characteristics of a swept-wing bomber with parasite swept-wing fighters coupled at the wing tips. The configuration is meant to represent an efficient towing arrangement whereby the operational range of fighters can be increased.
Date: February 14, 1956
Creator: Thompson, Robert F.
Partner: UNT Libraries Government Documents Department

The Correlation Between Carbon-Proton and Proton-Proton Coupling Constants

Description: The correlation between the carbon-proton and proton-proton coupling constants have been studied in various 13 systems. Isocrotonic acid-carboxyl-3C, crotonic acid- 13 13 carboxyl-3C, and 5-norbornene-2-carboxylic acid-carboxyl-3C- 1,5,6,7,7-hexachloro were synthesized and their carbonproton coupling constants were analyzed. Nmr studies showed the magnitudes of the carbon-proton coupling constants to correlate well with analogous protonproton coupling constants, although the values of the couplings were larger than expected. The geminal olefinic couplings were considerably larger than all other couplings, but they were self-consistent. The signs of the carbon-proton coupling constants also were in agreement without exception with the signs of analogous proton-proton coupling constants.
Date: December 1975
Creator: Seiwell, Ruth R.
Partner: UNT Libraries

THE COUPLING IMPEDANCE OF A TOROIDAL BEAM TUBE WITH CIRCULAR CROSS SECTION.

Description: IN THIS PAPER, THE LONGITUDINAL COUPLING IMPEDANCE OF A TOROIDAL BEAM TUBE WITH CIRCULAR CROSS SECION IS DERIVED IN THE FREQUENCY DOMAIN USING THE TOROIDAL COORDINATE SYSTEM. EXACT, ALTHOUGH COUPLED, DIFFERENTIAL EQUATIONS FOR THE AZIMUTHAL FIELD COMPONENTS ARE OBTAINED. AN APPROXIAMTE SOLUTION, VALID IN THE LIMIT OF SMALL CURVATURE, IS THEN DERIVED. ASSUMING EXTREME RELATIVISTIC ENERGIES AND A BEAM TUBE WITH PERFECTLY CONDUCTING WALLS, ONE FINDS A CLOSED-FORM EXPRESSION FOR THE PURELY REACTIVE COUPLING IMPEDANCE WHICH AT LOW MODE NUMBERS IS DEPENDENT ON THE TUBE GEOMETRY BUT WHICH AT VERY LARGE MODE NUMBERS APPROACHES THE FREE SPACE IMPEDANCE.
Date: March 29, 1999
Creator: HAHN,H.
Partner: UNT Libraries Government Documents Department

Fiscal Year 1998 report theoretical studies of ground energy coupling

Description: A method for calculating the redistribution of resonance radiation in hot, dense plasmas is developed by extending the Frequency Fluctuation Model (FFM). This paper is devoted to a brief review of lineshape theory in the linear response approximation, and an introduction to the FFM approach to the modeling of lineshapes in plasmas. This discussion begins with a consideration of the spectral lines emitted by complex ions in plasmas. As is well known, the lineshape is determined by the time- dependent coupling of the ion with the plasma environment. This plasma-emitter interaction, leads to Stark broadening of the spectral lines, and traditionally has been considered in the approximation which treats the ef&@ of the electrons on the emitting ion in the impact limit while the ionic perturbation is� taken to be quasi-static. In this approximation, the time dependence of the perturbation has been eliminated, resulting in a spectral line shape that has purely homogeneous and inhomogeneous contributions and that is described by a simple sum of independent electron imp� act broadened static components. In order to clarify the concepts presented, examples of radiative redistribution functions for simple cases are presented. Included is an example of an X-ray laser pumped system which illustrates the capability of the mpdel to provide a sensitive method for the study of radiative transfer under plasma conditions of partial redistribution. That is, in cases where the strong mixing limit is not attained so that the mixing of the inhomogeneous spectral line components is not fast enough to produce a completely redistributed line.
Date: December 10, 1998
Creator: Klein, L.
Partner: UNT Libraries Government Documents Department

Scalar and tensor couplings in kaon decays

Description: In the past few years charged kaon experiments have indicated possible scalar and tensor couplings in semileptonic kaon decays (K{yields}{pi}e{nu}). These couplings, if correct, are not predicted by the Standard Model and may indicate the onset of new physics. We present a summary of the existing data and a new, precision measurement of these couplings in the neutral kaon system based on a 3% subset of the data taken by the KTeV (E799) experiment at Fermilab.
Date: May 10, 1999
Creator: Tesarek, Richard J.
Partner: UNT Libraries Government Documents Department

Boson pair production and triple gauge couplings

Description: The D0 and CDF Collaborations measure boson pair production including W{gamma}, WW, WZ, ZZ and Z{gamma} production in p{anti p} collisions at {radical}s = 1800 GeV. New results, from direct measurements, are described including W{gamma}, WW, and Z{gamma} production cross sections and limits on non-Standard Model triple gauge boson couplings. The limits on anomalous WW{gamma}, WWZ, Z{gamma}{gamma} and ZZ{gamma} couplings are the most restrictive available. Prospects for Run II are discussed.
Date: June 1, 1997
Creator: Diehl, H.T. & Collaborations, D0 and CDF
Partner: UNT Libraries Government Documents Department

Waveguide Coupling via Magnetic Gratings with Effective Strips

Description: This article provides an overview of an approach convenient for describing intermediate gratings for two types of applications: both metafilms and the coupling of incident waves to waveguide modes or diffraction orders.
Date: February 20, 2018
Creator: Roccapriore, Kevin M.; Lyvers, David P.; Brown, Dean P.; Poutrina, Ekaterina; Urbas, Augustine M.; Germer, Thomas A. et al.
Partner: UNT College of Arts and Sciences

Atomic electron correlations in intense laser fields

Description: Abstract. This talk examines two distinct cases in strong opbical fields where electron correlation plays an important role in the dynamic.s. In the first. example, strong coupling in a two-electron-like system is manifested as an intensity-dependent splitting in the ionized electron energy distribution. This two-electron phenomenon (dubbed continuum-continuum Autler-Townes effect) is analogous to a strongly coupled two- level, one-electron atom but raises some intriguing questions regarding the exact nature of electron-electron correlation. The second case examines the evidence for two-electron ionization in the strong-field tunneling limit. Although our ability to describe the one- electron dynamics has obtained a quantitative level of understanding, a description of the two (multiple) electron ionization remains unc
Date: September 3, 1998
Creator: Agostini, P. A.; DiMauro, L. F.; Kulander, K.; Sheehy, B. & Walker, B.
Partner: UNT Libraries Government Documents Department

Carrier hopping in disordered semiconducting polymers: How accurate is the Miller-Abrahams model?

Description: We performed direct calculations of carrier hopping rates in strongly disordered conjugated polymers based on the atomic structure of the system, the corresponding electronic states and their coupling to all phonon modes. We found that the dependence of hopping rates on distance and the dependence of the mobility on temperature are significantly different than the ones stemming from the simple Miller-Abrahams model, regardless of the choice of the parameters in the model. A model that satisfactorily describes the hopping rates in the system and avoids the explicit calculation of electron-phonon coupling constants was then proposed and verified. Our results indicate that, in addition to electronic density of states, the phonon density of states and the spatial overlap of the wavefunctions are the quantities necessary to properly describe carrier hopping in disordered conjugated polymers.
Date: July 30, 2010
Creator: Vukmirovic, Nenad & Wang, Lin-Wang
Partner: UNT Libraries Government Documents Department

Linear Coupling Correction With N-Turn Maps.

Description: The linear one-turn map of a storage ring contains coupling information on which a correction algorithm can be based. In principal, the one-turn matrix can be fitted from turn-by-turn data of beam position monitors after a kick was applied. However, the so obtained coupling information often sinks into the noise floor. The signal-to-noise ratio of the coupling information can be greatly enhanced by fitting maps for larger turn numbers N, equal to half the beat period. With the so obtained N-turn map an automated global coupling correction is possible without the need for a tune change. This is demonstrated for the Relativistic Heavy Ion Collider where the algorithm is implemented for operational use at injection.
Date: May 12, 2003
Creator: Fischer, Wolfram
Partner: UNT Libraries Government Documents Department

Multiple Valley Couplings in Nanometer Si MOSFETs

Description: We investigate the couplings between different energy band valleys in a MOSFET device using self-consistent calculations of million-atom Schroedinger-Poisson Equations. Atomistic empirical pseudopotentials are used to describe the device Hamiltonian and the underlying bulk band structure. The MOSFET device is under nonequilibrium condition with a source-drain bias up to 2V, and a gate potential close to the threshold potential. We find that all the intervalley couplings are small, with the coupling constants less than 3 meV. As a result, the system eigenstates derived from different bulk valleys can be calculated separately. This will significantly reduce the simulation time, because the diagonalization of the Hamiltonian matrix scales as the third power of the total number of basis functions.
Date: July 11, 2008
Creator: Wang, Lin-Wang; Deng, Hui-Xiong; Jiang, Xiang-Wei; Luo, Jun-Wei; Li, Shu-Shen; Xia, Jian-Bai et al.
Partner: UNT Libraries Government Documents Department

A Brief Analog Investigation of Inertia Coupling in Rolling Maneuvers of an Airplane Configuration Using a Variable-Incidence Wing as the Longitudinal Control

Description: "An analog computer study was made in order to investigate the inertia coupling in rolling maneuvers of an airplane configuration utilizing a variable-incidence wing for longitudinal control. A five-degree-of-freedom system of equations was used, and only one set of flight conditions was included in this study. The results, when compared to those for a conventional tail-control airplane, indicated significant advantages for the variable-incidence-wing type of control in reducing undesired dynamic effects during rolling maneuvers" (p. 1).
Date: August 6, 1957
Creator: Gillis, Clarence L.
Partner: UNT Libraries Government Documents Department