12,289 research outputs found

    Fluid jet amplifier Patent

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    Fluid control jet amplifier

    Doppler radar with multiphase modulation of transmitted and reflected signal

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    A microwave radar signal is generated and split by a circulator. A phase shifter introduces a series of phase shifts into a first part of the split signal which is then transmitted by antenna. A like number of phase shifts is introduced by the phase shifter into the return signal from the target. The circulator delivers the phase shifted return signal and the leakage signal from the circulator to a mixer which generates an IF signal output at the Doppler frequency. The IF signal is amplified, filtered, counted per unit of time, and the result displayed to provide indications of target sense and range rate. An oscillator controls rate of phase shift in the transmitted and received radar signals and provides a time base for the counter. The phase shift magnitude increases may be continuous and linear or discrete functions of time

    Selected microgravity combustion diagnostic techniques

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    During FY 1989-1992, several diagnostic techniques for studying microgravity combustion have moved from the laboratory to use in reduced-gravity facilities. This paper discusses current instrumentation for rainbow schlieren deflectometry and thermophoretic sampling of soot from gas jet diffusion flames

    PROFITABILITY OF VARIABLE RATE PHOSPHORUS IN A TWO CROP ROTATION

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    In the Midwest, the adoption of precision farming technologies began in the early 1990s. Research has produced profiles of early adopters, evaluated adoption trends and has identified factors that influence the adoption and profitability of precision farming. Importantly, this information is available to producers, who are interested in precision farming issues. In addition, the Midwest regional agricultural industry, strong promoters of precision farming technologies, has gained the confidence of farmers who now rely on them heavily for information on farming technologies. Precision farming in Arkansas, however, is still in its infancy. Adoption levels lag far behind those in the Midwest. Two reasons for this lag have been offered. First, some suggest that much of what is believed about the technologies in the state is based on hearsay or the results of small single farm case study analyses. Because these beliefs have not been rigorously substantiated with extensive empirical evidence it has not been possible to truly assess the status of adoption, to predict potential adoption trends, or to adequately advise farmers in a decision to include precision farming in their farm management plan. Second, others suggest that agricultural industry has not taken an active role in the promotion and sale of precision farming equipment and services. Without local availability, all the research in the world will not lead to adoption of technology in the state. The objective of this paper is to provide critical information to Arkansas agricultural producers, industry and extension with answers regarding 1) the current status of precision farming 2) the amount, source and effectiveness of precision farming promotion and 3) the potential future of precision farming in Arkansas. In the Spring of 1999, three groups, early adopters of precision farming technologies (EA), Cooperative Extension Service personnel (CES) and agricultural industry personnel (AI), were surveyed to ascertain the realities and perceptions of precision farming in Arkansas. The surveys included questions related to characteristics of early adopters, factors encouraging and hindering adoption, and the roles of CES and AI in the promotion of precision farming within Arkansas. The survey response rate was over 60 percent. To build profiles of Arkansas EA to compare responses regarding sources of precision farming information across all three groups three statistical tools were used to test hypotheses regarding factors which influence adoption. The surveys revealed that Arkansas EA are young, educated, computer using, experienced farmers controlling relatively large farms predominantly devoted to rice and soybean. These farmers currently employ yield and soil mapping, as well as VRT and GIS technologies in their operations. While many reasons (such as decreased costs, improved yields, and improved management capabilities) have been cited as factors that can encourage adoption, there are still any number of reasons why many Arkansas farmers have not yet adopted these technologies, including, technical difficulties, expense and unproven profitability. In addition, AI representatives see themselves as promoters of precision farming technologies in Arkansas while EA have cited instances of a lack of available equipment and also stated that they turn to CES rather than AI for farming information because they believe this is an unbiased source of information. The authors conclude that both reasons offered for the lag in adoption are likely and hope that these insights provide both the CES and AI representatives with information to help them focus their research and outreach activities so that more Arkansas producers can make informed decisions about precision farming.Crop Production/Industries,

    Flueric-controller pneumatic stepping motor system

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    Nutating stepping motor consists of an output rotating gear and a nutating gear. A flueric logic circuit controls the nutating motor. The complete system constitutes a reliable, open loop actuator system with inherently high output stiffness, reasonable slewing speeds and small step size

    Acoustic waves and heating due to molecular energy transfer in an electric discharge CO laser

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    This paper summarizes analytical studies and the interpretation of experimental results for the compression and rarefaction waves generated in the cavity of a pulsed CO electric discharge laser. A one-dimensional analysis of acoustic waves is applied to a transversely excited laser. The influences of heating in the cathode fall, heat transfer to the cathode, flow through both the anode and cathode, and bulk heating of the plasma are included. The analysis is used to relate the bulk heating rate to observable features of the pressure and density waves. Data obtained from interferograms and reported elsewhere are used to infer the bulk heating rates in a pulsed CO laser. Results are presented for CO/Ar, CO/N2, and N2 plasmas. Comparison of the data with recent theoretical results for the heating due to electron/ neutral collisions and the anharmonic defect associated with V-V energy transfer shows substantial differences at lower values of total energy deposition. The change of heating with E/N is in fairly good agreement with predicted values

    A breadboard flueric-controlled pneumatic stepping motor system

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    Breadboard flueric circuitry used to drive pneumatic stepping motor

    Design of a fluid jet amplifier with reduced receiver-interaction-region coupling

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    Fluid jet amplifier design with reduced receiver interaction region couplin

    Long-term material compatibility testing system

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    System includes procedure for hermetically sealing solid materials and fluids in glass ampoule and use of temperature-controlled facility containing sample holder, which permits sample containers to be retrieved safely and conveniently. Solid material and fluid are sealed within chemically-clean glass ampoule according to highly detailed procedure
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