784 research outputs found

    Electronic compensation for reflector surface distortion to improve radiation pattern characteristics of antennas

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    A simple procedure is described for determining the excitation coefficients of an array feed which compensates for the surface distortion of a reflector antenna to improve the radiation pattern in such a way as to approximate the performance of the undistorted antenna. A computer simulation for a practical feed array is presented as an example of compensation for the distortion of an actual antenna

    High Automation, Fascism, and Our Social Revolution

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    The United States in the present day has experienced a rise of both incredibly productive automated technologies, approaching self-perpetuation, and fascism, entering and affecting significant social institutions. This paper aims to explain these phenomenon with the Marxist mechanics of the historical dialectic, conceptions of abstraction and material, and the behavior of capital – among other modes of production – and predict the broader development that is oncoming. It has been found that the rise of advanced and self-perpetuating automating technologies is indicative of an oncoming mode of production, ‘high automation’, and that fascism itself is a character, or subdialectical stage, of capitalism, which periodically appear during transitions under capitalism. Therein a social revolution, or reconstruction, to high automation is oncoming

    Evolution and Modern Approaches for Thermal Analysis of Electrical Machines

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    In this paper, the authors present an extended survey on the evolution and the modern approaches in the thermal analysis of electrical machines. The improvements and the new techniques proposed in the last decade are analyzed in depth and compared in order to highlight the qualities and defects of each. In particular, thermal analysis based on lumped-parameter thermal network, finite-element analysis, and computational fluid dynamics are considered in this paper. In addition, an overview of the problems linked to the thermal parameter determination and computation is proposed and discussed. Taking into account the aims of this paper, a detailed list of books and papers is reported in the references to help researchers interested in these topics

    DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2lasers

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    A parametric analysis of DIAL sensitivity with heterodyne detection is presented and comparisons with direct detection are discussed. Examples are given for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system. Results indicate that maximum sensitivity at minimum laser energy per measurement requires multiple pulse operation with the energy per pulse selected so that the measured photon rate is approximately equal to the detector IF bandwidth. Measurement sensitivities can be maximized and interference effects minimized by fine adjustment of measurement frequencies using the tunability of high pressure lasers. The use of rare isotope lasers minimizes loss due to CO2 atmospheric absorption

    DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2 lasers

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    Atmospheric trace constituent measurements with higher vertical resolution than attainable with passive radiometers are discussed. Infrared differential absorption lidar (DIAL), which depends on Mie scattering from aerosols, has special advantages for tropospheric and lower stratospheric applications and has great potential importance for measurements from shuttle and aircraft. Differential absorption lidar data reduction involves comparing large amplitude signals which have small differences. The accuracy of the trace constituent concentration inferred from DIAL measurements depends strongly on the errors in determining the amplitude of the signals. Thus, the commonly used SNR expression (signal divided by noise in the absence of signal) is not adequate to describe DIAL measurement accuracy and must be replaced by an expression which includes the random coherent (speckle) noise within the signal. A comprehensive DIAL computer algorithm is modified to include heterodyne detection and speckle noise. Examples for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system are given

    Age of First Arrest, Sex, and Drug Use as Correlates of Adult Risk Behaviors Among Rural Women in Jails

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    Incarcerated women frequently report initiation of substance use and sexual encounters at an early age, and often engage in high-risk drug use and sexual behaviors as adults. This study examined the timing of first sex, drug use, and arrest, as well as their unique influences on specific risky behaviors in adulthood, among a high-risk population of rural women recruited from jails. Ages of initiation were all positively and significantly correlated, and each independently increased the likelihood of several risky behaviors in adulthood. Implications are discussed for screening, intervention, and treatment targeting high-risk women and girls in rural areas, particularly within criminal justice settings

    Propulsion Study for Small Transport Aircraft Technology (STAT)

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    Propulsion requirements were determined for 0.5 and 0.7 Mach aircraft. Sensitivity studies were conducted on both these aircraft to determine parametrically the influence of propulsion characteristics on aircraft size and direct operating cost (DOC). Candidate technology elements and design features were identified and parametric studies conducted to select the STAT advanced engine cycle. Trade off studies were conducted to determine those advanced technologies and design features that would offer a reduction in DOC for operation of the STAT engines. These features were incorporated in the two STAT engines. A benefit assessment was conducted comparing the STAT engines to current technology engines of the same power and to 1985 derivatives of the current technology engines. Research and development programs were recommended as part of an overall technology development plan to ensure that full commercial development of the STAT engines could be initiated in 1988

    Teaching Case Conceptualization Skills to Clinical Mental Health Students to Enhance Clinical Competency and Cognitive Complexity

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    A primary purpose of counselor education is the development of competency in diagnosis, case conceptualization, treatment formulation, and intervention. This paper describes a series of experiential case-based workshops designed to directly target and enhance students’ understanding of these specific clinical mental health counseling competencies in order to promote student involvement in constructivist learning, develop students’ cognitive complexity, and elucidate the thinking of an experienced clinician. This paper provides an overview of the workshop design and implementation, discussion of workshop efficacy with examples, and suggestions for curricular implementation

    Development of electromagnetic analysis methods for large aperture antennas

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    Both deterministic and statistical analysis methods for investigating large aperture antenna radiation patterns are examined. The effects of surface errors on radiation patterns are discussed

    Study of an advanced General Aviation Turbine Engine (GATE)

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    The best technology program for a small, economically viable gas turbine engine applicable to the general aviation helicopter and aircraft market for 1985-1990 was studied. Turboshaft and turboprop engines in the 112 to 746 kW (150 to 1000 hp) range and turbofan engines up to 6672 N (1500 lbf) thrust were considered. A good market for new turbine engines was predicted for 1988 providing aircraft are designed to capitalize on the advantages of the turbine engine. Parametric engine families were defined in terms of design and off-design performance, mass, and cost. These were evaluated in aircraft design missions selected to represent important market segments for fixed and rotary-wing applications. Payoff parameters influenced by engine cycle and configuration changes were aircraft gross mass, acquisition cost, total cost of ownership, and cash flow. Significant advantage over a current technology, small gas turbine engines was found especially in cost of ownership and fuel economy for airframes incorporating an air-cooled high-pressure ratio engine. A power class of 373 kW (500 hp) was recommended as the next frontier for technology advance where large improvements in fuel economy and engine mass appear possible through component research and development
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