129,421 research outputs found

    Phase modulator Patent

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    Phase modulator with tuned variable length electrical lines including coupling and varactor diode circuit

    An attentional control task reduces intrusive thoughts about smoking.

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    INTRODUCTION: Attentional control tasks such as body scanning and following isometric exercise instructions have been shown to reduce smoking cravings, apparently by reducing stress (Ussher, M., Cropley, M., Playle, S., Mohidin, R., & West, R. [2009]. Effect of isometric exercise and body scanning on cigarette cravings and withdrawal symptoms. Addiction, 104, 1251-1257. doi:10.1111/j.1360-0443.2009.02605.x). Related work based upon elaborated intrusion theory (Kavanagh, D. J., Andrade, J., & May, J. [2005]. Imaginary relish and exquisite torture: The elaborated intrusion theory of desire. Psychological Review, 112, 446-467. doi:10.1037/0033-295X.112.2.446) has shown that similar tasks can reduce hungry participants' involuntary food-related thoughts (May, J., Andrade, J., Batey, H., Berry, L.-M., & Kavanagh, D. [2010]. Less food for thought: Impact of attentional instructions on intrusive thoughts about snack foods. Appetite, 55, 279-287. doi:10.1016/j.appet.2010.06.014). This study tests the effect of body scanning instructions upon smoking-related thoughts as well as craving. METHODS: Twenty-seven smokers took part in 2 counterbalanced sessions, on different days, having been asked to abstain from smoking for 2 hr. In each session, they followed audio instructions for three 10-min blocks during which their thoughts were probed 10 times. In the first and third blocks, they were instructed to let their mind wander; during the second block of the control session, they also let their mind wander, but in the experimental session, they followed body scanning instructions. "Smoking thought frequency" was assessed using thought probes; "Craving" was measured using Factor 1 of the Questionnaire on Smoking Urges (Tiffany, S. T., & Drobes, D. J. [1991]. The development and initial validation of a questionnaire on smoking urges. British Journal of Addiction, 86, 1467-1476. doi:10.1111/j.1360-0443.1991.tb01732.x). RESULTS: Participants reported fewer smoking-related thoughts and lower smoking cravings in the body scanning block of the experimental session, whereas they rose in the comparable mind-wandering block of the control session. The reduction in thoughts during the body scanning correlated with the corresponding reduction in craving. CONCLUSIONS: Body scanning reduces cravings and reduces the frequency or shortens the duration of smoking thoughts. Attentional control strategies may form a useful part of smoking cessation practices

    Quasi non-intrusive sampling and analysis of gases associated with the boundary layer on the tethered satellite and similar supersonic and hypersonic research vehicles

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    The effect that one candidate inlet, an assembly of capillary openings in a thin glass plate (a multichannel plate), might have on the overall sampling process is considered. The flow characteristics of the plate, under a variety of conditions of external pressure and mass flow, is evaluated. A review of capillary flow theory is presented with some development of the pertinent equations. The predicted mass flow will be compared to that determined perimentally to assess the effect that mass flow through one capillary might have upon a neighboring capillary. Mass spectrometric measurements of mixtures flowing through the multichannel plate (MCP) is also considered. In the first part of the experiments, the flow was in a direction normal to the surface of the plate. The experimental gases were Argon and mixtures of carbon dioxide in air. Ongoing experiments are discussed which are conducted with the flow parallel to the surface of the plate, a simulation of the kind of flow that a flight vehicle would experience

    Fluctuations and massive separation in three-dimensional shock-wave/boundary-layer interactions

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    Shock-wave unsteadiness was observed in rapidly compressed supersonic turbulent boundary layer flows with significant separation. A Mach 2.85 shock-wave/turbulent boundary layer flow was set up over a series of cylinder-flare bodies in the High Reynolds Number Channel 1. The transition from fully attached to fully separated flow was studied using axisymmetric flares with increasing compression angles. In the second phase, the 30 deg flare was inclined relative to the cylinder axis, so that the effect on a separated flow of increasing 3 dimensionality could be observed. Two 3-D separated cases are examined. A simple conditional sampling technique is applied to the data to group them according to an associated shock position. Mean velocities and turbulent kinetic energies, computed from the conditionally samples data, are compared to those from the unsorted data and to computed values. Three basic questions were addressed: can conditional sampling be used to provide snapshots of the flow; are averaged turbulence quantities dominated by the bimodal nature of the interaction; and is the shock unsteadiness really important to computational accuracy

    Shock associated noise reduction from inverted-velocity-profile coannular jets

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    Acoustic measurements show that the shock noise from the outer stream is virtually eliminated when the inner stream is operated at a Mach number just above unity, regardless of all the other jet operating conditions. At this optimum condition, the coannular jet provides the maximum noise reduction relative to the equivalent single jet. The shock noise reduction can be achieved at inverted-as well as normal-velocity-profile conditions, provided the coannular jet is operated with the inner stream just slightly supersonic. Analytical models for the shock structure and shock noise are developed indicate that a drastic change in the outer stream shock cell structure occurs when the inner stream increases its velocity from subsonic to supersonic. At this point, the almost periodic shock cell structure of the outer stream nearly completely disappears the noise radiated is minimum. Theoretically derive formulae for the peak frequencies and intensity scaling of shock associated noise are compared with the measured results, and good agreement is found for both subsonic and supersonic inner jet flows
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