Economical phased-array antenna for environmental applications

Antenna system handles data acquisition and tracking, functions as a sensitive radio telescope, and serves as a radiometer in earth atmosphere investigations. Antenna's sensitivity permits resolution of solar disk quadrants in Doppler radar observations. Antenna also serves as a planetary radar device and link to commercial aircraft

Design of printed circuit coils

Spiral-like coil is printed with several extra turns which increase the realizable coil inductance. Included are shorting connections which not only short the extra turns, but also short out several turns of the main body. Coil tuning is accomplished by removing the shorts until the desired inductance is obtained

Coolant passage heat transfer with rotation

The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques, and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades

Structures Produced by the Collision of Extragalactic Jets with Dense Clouds

We have investigated how several parameters can affect the results of a collision between an extragalactic jet and a dense, intergalactic cloud, through a series of hydrodynamic simulations. Such collisions are often suggested to explain the distorted structures of some radio jets. However, theoretical studies of this mechanism are in conflict over whether it can actually reproduce the observations. The parameters are the Mach number, and the relative densities of the jet and the cloud to the ambient medium. Using a simple prescription we have produced synthetic radio images for comparison with observations. These show that a variety of structures may be produced from simple jet-cloud collisions. We illustrate this with a few examples, and examine the details in one case. In most cases we do not see a clear, sustained deflection. Lighter jets are completely disrupted. The most powerful jets produce a hotspot at the impact which outshines any jet emission and erode the cloud too quickly to develop a deflected arm. It appears that moderate Mach numbers and density contrasts are needed to produce bends in the radio structure. This explains the apparent conflict between theoretical studies, as conclusions were based on different values of these parameters. Shocks are produced in the ambient medium that might plausibly reproduce the observed alignment of the extended emission line regions with the radio axis.Comment: 21 pages, 11 figures. Submitted to MNRAS. Also available in html version at http://www.doc.mmu.ac.uk/STAFF/S.Higgins/jcmnpaper/jc_mn.htm

Exhaust jet wake and thrust characteristics of several nozzles designed for VTOL DOWNWASH suppression. Tests in and out of ground effect with 70 deg F and 1200 deg F nozzle discharge temperatures

Jet wake degradation and thrust characteristics of exhaust nozzles designed for VTOL downwash suppression and fuselage and ground effect

Unified powered flight guidance

A complete revision of the orbiter powered flight guidance scheme is presented. A unified approach to powered flight guidance was taken to accommodate all phases of exo-atmospheric orbiter powered flight, from ascent through deorbit. The guidance scheme was changed from the previous modified version of the Lambert Aim Point Maneuver Mode used in Apollo to one that employs linear tangent guidance concepts. This document replaces the previous ascent phase equation document

Coexistence of Antiferromagnetism and Superconductivity in Electron-doped High-Tc Superconductors

We present magnetotransport evidence for antiferromagnetism in films of the electron-doped cuprates Pr$_{2-x}$Ce$_x$CuO$_4$. Our results show clear signature of static antiferromagnetism up to optimal doping x=0.15, with a quantum phase transition close to x=0.16, and a coexistence of static antiferromagnetism and superconductivity for 0.12$\le$x$\le$0.15

A study to determine an efficient data format and data system for a lightweight deep space probe

Design of spacebore central data system for solar probe

Research in and the Application of Modern Automatic Control Theory to Nuclear Rocket Dynamics and Control Semiannual Status Report, Vol. II

Second Method of Liapunov, Popov frequency criterion, and matrix inequality method used to study stability of nonlinear and/or time dependent control system

The gatekeeper: individual differences are key in the chain from perception to behaviour

A basic assumption in mainstream social cognition is that the path from perception to behaviour is often automatic and direct, as supported for example by several experimental studies showing that priming can lead directly to a congruent behaviour without any need of conscious awareness of the process. However, we argue that the priming of a goal or an object activates individual differences in automatic evaluations at the associative level that in turn are the key predictors of action (gatekeeper model). A study (n = 90) on the American stereotype is presented to support the model. The results show that individual differences of the American stereotype as assessed with the IAT predicts a relevant action (essay evaluation) but only under condition of priming. Broader implications for predictive validity of implicit measures are also discussed