5,937 research outputs found
A miniature 1/4-inch diameter 24-pin plug and receptacle
Miniature plug and receptacle, which eliminates the need for permanent fixed leads, is used on wind-tunnel force balances, in the interface connections of microelectronic modular assemblies, and in electric and electronic systems where subsystems must be removed or interchanged
The colloidal chemistry of ceramic clays
The colloidal chemistry and mineralogy of two argil minerals were studied. Deposits of kaolin and of ceramic clays in the United States and England are discussed for the probable mechanism of formation. The structural modifications of the bed, original material associated with the clays and the proper use of flocculants are discussed
The role of water in slip casting
Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface
A teleoperated unmanned rotorcraft flight test technique
NASA and the U.S. Army are jointly developing a teleoperated unmanned rotorcraft research platform at the National Aeronautics and Space Administration (NASA) Langley Research Center. This effort is intended to provide the rotorcraft research community an intermediate step between wind tunnel rotorcraft studies and full scale flight testing. The research vehicle is scaled such that it can be operated in the NASA Langley 14- by 22-Foot Subsonic Tunnel or be flown freely at an outside test range. This paper briefly describes the system's requirements and the techniques used to marry the various technologies present in the system to meet these requirements. The paper also discusses the status of the development effort
Upper-surface-blowing flow-turning performance
Jet exhaust flow-turning characteristics were determined for systematic variations in upper-surface blowing exhaust nozzles and trailing-edge flap configuration variables from experimental wind-off (static) flow studies. For conditions with parallel flow exhausting from the nozzle, jet height (as indicated by nozzle exit height) and flap radius were found to be the most important parameters relating to flow turning. Nonparallel flow from the nozzle, as obtained from an internal roof angle and/or side spread angle, had a large favorable effect on flow turning. Comparisons made between static turning results and wind tunnel aerodynamic studies of identical configurations indicated that static flow-turning results can be indicative of wind-on powered lift performance for both good and poor nozzle-flap combinations but, for marginal designs, can lead to overly optimistic assessment of powered lift potential
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