Experimental evaluation of shape memory alloy actuation technique in adaptive antenna design concepts

Creation of an antenna system that could autonomously adapt contours of reflecting surfaces to compensate for structural loads induced by a variable environment would maximize performance of space-based communication systems. Design of such a system requires the comprehensive development and integration of advanced actuator, sensor, and control technologies. As an initial step in this process, a test has been performed to assess the use of a shape memory alloy as a potential actuation technique. For this test, an existing, offset, cassegrain antenna system was retrofit with a subreflector equipped with shape memory alloy actuators for surface contour control. The impacts that the actuators had on both the subreflector contour and the antenna system patterns were measured. The results of this study indicate the potential for using shape memory alloy actuation techniques to adaptively control antenna performance; both variations in gain and beam steering capabilities were demonstrated. Future development effort is required to evolve this potential into a useful technology for satellite applications

Development of a HTSMA-Actuated Surge Control Rod for High-Temperature Turbomachinery Applications

In recent years, a demand for compact, lightweight, solid-state actuation systems has emerged, driven in part by the needs of the aeronautics industry. However, most actuation systems used in turbomachinery require not only elevated temperature but high-force capability. As a result, shape memory alloy (SMA) based systems have worked their way to the forefront of a short list of viable options to meet such a technological challenge. Most of the effort centered on shape memory systems to date has involved binary NiTi alloys but the working temperatures required in many aeronautics applications dictate significantly higher transformation temperatures than the binary systems can provide. Hence, a high temperature shape memory alloy (HTSMA) based on NiTiPdPt, having a transformation temperature near 300 C, was developed. Various thermo-mechanical processing schemes were utilized to further improve the dimensional stability of the alloy and it was later extruded/drawn into wire form to be more compatible with envisioned applications. Mechanical testing on the finished wire form showed reasonable work output capability with excellent dimensional stability. Subsequently, the wire form of the alloy was incorporated into a benchtop system, which was shown to provide the necessary stroke requirements of approx.0.125 inches for the targeted surge-control application. Cycle times for the actuator were limited to ~4 seconds due to control and cooling constraints but this cycle time was determined to be adequate for the surge control application targeted as the primary requirement was initial actuation of a surge control rod, which could be completed in approximately one second

NSF/ESF Workshop on Smart Structures and Advanced Sensors, Santorini Island, Greece, June 26-28, 2005: Structural Actuation and Adaptation Working Group

This document is a result of discussions that took place during the workshop. It describes current state of research and development (R&D) in the areas of structural actuation and adaptation in the context of smart structures and advanced sensors (SS&AS), and provides an outlook to guide future R&D efforts to develop technologies needed to build SS&AS. The discussions took place among the members of the Structural Actuation and Adaptation Working Group, as well as in general sessions including all four working groups. Participants included members of academia, industry, and government from the US and Europe, and representatives from China, Japan, and Korea

Validation Report for the EO-1 Lightweight Flexible Solar Array Experiment

The controlled deployment of the Lightweight Flexible Solar Array (LFSA) experiment using the shape memory alloy release and deployment system has been demonstrated. Work remains to be done in increasing the efficiency of Copper Indium Diselinide (CIS) terminations to the flexible harness that carries current from the array to the I-V measurement electronics

Advanced Photovoltaic Power System Development at the U.S. Air Force Research Laboratory

Photovoltaics continue to be the primary source of electrical power for most near-Sun space missions. The desire to enhance or enable new space missions through higher efficiency, increased specific power (W/kg), increased volumetric power density (W/m3) and improved radiation resistance, along with decreased costs, continues to push the development of novel solar cell and array technologies. To meet present and future space power requirements, advanced multijunction solar cells and novel cell technologies are being pursued. These efforts have resulted in a continual advancement in performance, but new paradigms will be required to continue that performance trend. Similarly, new array technologies are being investigated and developed to meet the ever increasing power system performance requirements

ART PEPPER + ELEVEN / Art PEPPER et une formation de jazz

Titre uniforme : ['Round Midnight]Titre uniforme : ['Round about midnight]Titre uniforme : ['Round about midnight]Titre uniforme : [Groovin'high]Titre uniforme : [Move]Comprend : MOVE / Denzil BEST - GROOVIN' HIGH / Dizzy GILLESPIE - OPUS DE FUNK / Horace SILVER - ROUND MIDNIGHT / Bernie HANIGHEM - Cootie WILLIAMS et Thelonius MONK - FOUR BROTHERS / Jimmy GIUFFRE - SHAWNUFF / Dizzy GILLESPIE - BERNIE'S TUNE / Bernie MILLER - WALKIN' SHOES / Gerry MULLIGAN - ANTHROPOLOGY / Dizzy GILLESPIE - AIREGIN / Sonny ROLLINS - WALKIN' / Richard CARPENTER - DONNA LEE / Charlie PARKERBnF-Partenariats, Collection sonore - BelieveContient une table des matière

Rhythm is my business / Ella Fitzgerald, chant ; avec Bill Doggett, org., dir.

Comprend : ROUGH RIDIN' / Ella Fitzgerald ; Hank Jones et William Tennyson - BRODWAY / Henry Woods ; Teddy Mc Ray et Bill Bird - You can depend on me / Charles Carpenter ; Louis Dunlap et Earl Hines - RUNNIN' WILD / Joe Grey ; Leo Wood et Arthur H. Gibbs - SHOW ME THE WAY TO GO OUT OF THIS WORLD' CAUSE THAT'S WHERE EVERY THING IS / Lee Clark et Matt Dennis - I'LL ALWAYS BE IN LOVE WITH YOU / Herman Ruby ; Bud Green et Sam H. Stept - HALLELUJAH ! LOVE HIM SO / Ray Charles - I CAN'T FACE THE MUSIC / Ted Koehler et Rube Bloom - NO MOON AT ALL / Red Evans et Dave Mann - LAUGHING ON THE OUTSIDE / Ben Raleigh et Bernie Wayne - AFTER YOU'VE GONE / Henry Creamer et Turner LaytonBnF-Partenariats, Collection sonore - BelieveContient une table des matière