Experimental and theoretical aerodynamic characteristics of two hypersonic cruise aircraft concepts at Mach numbers of 2.96, 3.96, and 4.63

The longitudinal and lateral directional aerodynamic characteristics for two Mach 5 cruise aircraft concepts were determined for test Mach numbers of 2.96, 3.96, and 4.63. Estimates from hypersonic impact theory and first order supersonic linearized theory were compared with data to indicate the usefulness of these methods. The method which applied tangent cone empirical theory to the body and tangent wedge theory to the wings and to the horizontal and vertical tails provided the best estimates. The tangent cone empirical theory applied to all components showed poor agreement with data, and the linear theory estimates were accurate only for lift coefficient and drag coefficient at low angles of attack

Development and performance of pulse-width-modulated static inverter and converter modules

Pulse-width-modulated inverter and converter modules are being developed for modular aerospace electrical power systems. The modules, rate 2.5 kilowatts per module and 10-minute - 150-percent overload, operate from 56 volts dc. The converter module provides two output voltages: a nominal link voltage of 200 volts dc when used with the inverter, and 150 volts dc to a load bus when used separately. The inverter module output is 400-hertz, sinusoidal, three-phase, 120/208 volts. Tests of breadboard models with standard parts and integrated circuits show rated power efficiencies of 71.4 and 85.1 percent and voltage regulation of 5 and 3.1 percent for inverter and converter modules, respectively. Sine-wave output distortion is 0.74 percent

Effect Of Early Childhood Tobacco Education Program On Knowledge And Attitudes Of Elementary Students

Tobacco use is recognized as the number one preventable cause of disease and death in the United States. As such, development of better tobacco-use prevention strategies, utilized by health care providers, is a worthy endeavor. Where it exists, initiation of formal tobacco education within the schools is focused at sixth- to eighth-grade students, the age research has shown when most tobacco experimentation begins, yet well beyond the age when ideas and attitudes are developed in favor of or in opposition to tobacco use. The purpose of this quasi-experimental study was to determine the effect of an early childhood tobacco education program on knowledge and attitudes of fourth-grade students. A convenience sample of 234 students from an elementary school in the southeastern United States was compared to a control group of 4 6 students from an area school of similar size and demographics who had not been exposed to the tobacco curriculum. Bandura\u27s Social Learning Theory and the Neuman Systems Model provided the theoretical frameworks to guide the study. The Tupelo Tobacco Survey, an instrument used to measure scores in knowledge and attitude, was developed from an existing tool by Princeton Health Press. The null hypotheses tested were as follows : There will be no difference in knowledge scores for students who attended and those who did not attend an early education program and there will be no difference in attitude scores for students who attended and those who did not attend an early education program. Descriptive statistics were used and included frequencies, percentiles, and t test for data analysis. A statistically significant difference (p \u3c .001) was found for knowledge test scores, thus the first hypothesis was rejected. The null hypothesis, however, was accepted in statement two, since no difference emerged for attitude scores. This result was attributed to a ceiling effect explained by a preexisting high negative attitude toward tobacco use in both groups of children. The researcher concluded that an early childhood tobacco education is effective as a tobacco-use prevention strategy. There is an obvious role for the advanced practice nurse in the school setting relative to providing this health education foundation. The researcher recommends the incorporation of tobacco education at an earlier age to effectively generate a knowledgeable youth population and promote attitudes consistent with postponement or abstinence of tobacco use onset

Verification tests of durable TPS concepts

Titanium multiwall, superalloy honeycomb, and Advanced Carbon-carbon (ACC) multipost Thermal Protection System (TPS) concepts are being developed to provide durable protection for surfaces of future space transportation systems. Verification tests including thermal, vibration, acoustic, water absorption, lightning strike, and aerothermal tests are described. Preliminary results indicate that the three TPS concepts are viable up to a surface temperature in excess of 2300 F

Probabilistic Quantum Encoder for Single-Photon Qubits

We describe an experiment in which a physical qubit represented by the polarization state of a single-photon was probabilistically encoded in the logical state of two photons. The experiment relied on linear optics, post-selection, and three-photon interference effects produced by a parametric down-conversion photon pair and a weak coherent state. An interesting consequence of the encoding operation was the ability to observe entangled three-photon Greenberger-Horne-Zeilinger states.Comment: 4 pages, 4 figures; submitted to Phys. Rev.

The far field diffraction pattern for corner reflectors with complex reflection coefficients

The far field diffraction pattern of a geometrically perfect corner reflector is examined analytically for normally incident monochromatic light. The states of polarization and the complex amplitudes of the emerging light are expressed through transformation matrices in terms of those of the original incident light for each sextant of the face in a single coordinate system. The analytic expression of the total diffraction pattern is obtained for a circular face. This expression consists of three component functions in addition to the basic Airy function. The coefficient of each function is expressed in terms of complex coefficients of reflectance of the reflecting surface. Some numerical results for different reflecting surfaces, including total internal reflection, are presented. The iso-intensity contours of the diffraction pattern evaluated from the analytical expressions for an uncoated solid corner reflector are also presented along with the photographs of the pattern

Conditional linear-optical measurement schemes generate effective photon nonlinearities

We provide a general approach for the analysis of optical state evolution under conditional measurement schemes, and identify the necessary and sufficient conditions for such schemes to simulate unitary evolution on the freely propagating modes. If such unitary evolution holds, an effective photon nonlinearity can be identified. Our analysis extends to conditional measurement schemes more general than those based solely on linear optics.Comment: 16 pages, 2 figure

Geophysical constraints on the thickness of the Holyrood Pluton, Avalon Peninsula, Newfoundland

The vertical extent of the Holyrood Pluton and the surrounding Harbpur Main Group of the northeastern Avalon Peninsula of Newfoundland is estimated using two-dimensional gravity and magnetic models. The models are interpreted to indicate that the maximum thickness of the Holyrood Pluton is 1.8 km and that mafic Harbour Main volcanics must exist beneath the pluton and be confined to the uppnr 2.0 km of the crust west of the Conception/Cabot Group boundary on the eastern portion of the survey area. RÉSUMÉ En utilisant des modèles à deux dimensions de gravite et de magnétisme, on a estime l’étendue verticale du pluton Holyrood et du groupe circonvoisin de Harbour Main dans l'est de la peninsule Avalon, Terre-Neuve. L'interprètation des modèles indique que lépaisseur maximale du pluton Holyrood atteint 1.8 km et que des roches volcaniques mafiques du groupe Harbour Main doivent se trouver sous le pluton et restreintes aux 2.0 km supérieurs de l'écorce se trouvant à l'ouest de la limite des groupes de Conception et de Cabot, dans la partie orientale de la région étudiée. [Traduit par le journal