3,947 research outputs found

    Metabolic simulation chamber

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    Metabolic simulation combustion chamber was developed as subsystem for breathing metabolic simulator. Entire system is used for evaluation of life support and resuscitation equipment. Metabolism subsystem simulates a human by consuming oxygen and producing carbon dioxide. Basic function is to simulate human metabolic range from rest to hard work

    Temperature and humidity control of simulated human breath

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    Subsystem was developed for breathing metabolic simulator which adjusts temperature and humidity of air to levels of human exhaled breath. Temperature-humidity subsystem is described, consisting of aluminum enclosure with 400 watt heat sheet glued to bottom, vertical separators, inlet connection, and check valve

    Assessment of variations in thermal cycle life data of thermal barrier coated rods

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    An analysis of thermal cycle life data for 22 thermal barrier coated (TBC) specimens was conducted. The Zr02-8Y203/NiCrAlY plasma spray coated Rene 41 rods were tested in a Mach 0.3 Jet A/air burner flame. All specimens were subjected to the same coating and subsequent test procedures in an effort to control three parametric groups; material properties, geometry and heat flux. Statistically, the data sample space had a mean of 1330 cycles with a standard deviation of 520 cycles. The data were described by normal or log-normal distributions, but other models could also apply; the sample size must be increased to clearly delineate a statistical failure model. The statistical methods were also applied to adhesive/cohesive strength data for 20 TBC discs of the same composition, with similar results. The sample space had a mean of 9 MPa with a standard deviation of 4.2 MPa

    Effect of thermal cycling on ZrO2-Y2O3 thermal barrier coatings

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    A study was made of the comparative life of plasma sprayed ZrO2-Y2O3 thermal barrier coatings on NiCrAlY bond coats on Rene 41 in short (4 min) and long (57 min) thermal cycles to 1040 C in a 0.3 Mach flame. Short cycles greatly reduced the life of the ceramic coating in terms of time at temperature as compared to longer cycles. Appearance of the failed coating indicated compressive failure. Failure occurred at the bond coat-ceramic coat junction. At heating rates greater than 550 kw/sq m, the calculated coating detachment stress was in the range of literature values of coating adhesive/cohesive strength. Methods are discussed for decreasing the effect of high heating rate by avoiding compressive stress

    Metallic and metalloceramic coating by thermal decomposition

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    Metallic and metalloceramic coatings were prepared by thermal decomposition of a number of inorganic and metallo-organic compounds. The compounds were applied by spraying and by immersion, especially on ceramic fibers and fiber forms, which are easily coated by this procedure. Penetration of low-density ceramics is examined, and procedures are described that were used for converting the deposited materials to metals, oxides, or metal oxide films. Multiple-component films were also prepared. Photomicrographs illustrate the structure of these films

    Use of fiber like materials to augment the cycle life of thick thermoprotective seal coatings

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    Some experimental and analytical studies of plasma sprayed ZrO2-Y2O3 thick seal thermoprotective materials over NiCrAlY bond coats with testing to 1040 deg C in a Mach 0.3 burner flame are reviewed. These results indicate the need for material to have both compliance and sufficient strength to function successfully as a thick thermoprotective seal material. Fibrous materials may satisfy many of these requirements. A preliminary analysis simulating the simplified behavior of a 25 mm cylindrical SiO2-fiber material indicated significant radial temperature gradients, a relatively cool interface and generally acceptable stresses over the initial portion of the thermal cycle. Subsequent testing of these fiberlike materials in a Mach 0.3 Jet A/air burner flame confirmed these results

    Evaluation of high temperature structural adhesives for extended service

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    The preliminary evaluation of crosslinked polyphenyl quinoxaline (X-PPQ), LARC-TPI, ethyl terminated polysulfone (ETPS), and crosslinked polyimide (X-PI) as adhesives is presented. Lap shear strength stability under thermal, combined thermal/humidity, and stressed and unstressed Skydrol exposure was determined. The X-PPQ, LARC-TPI, and X-PI exhibited good adhesive performance at 505K (450 F) after 1000 hours at 505K. These three polymers also performed well after exposure to combined elevated temperature/high humidity, as well as, to Skydrol while under stress. The ETPS exhibited good ambient temperature adhesive properties, but performed poorly under all other exposure conditions, presumably due to inadequate chain extension and crosslinking

    Superconducting gyroscope research

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    Four basic areas of research and development of superconducting gyroscopes are studied. Chapter 1 studies the analysis of a SQUID readout for a superconducting gyroscope. Chapter 2 studies the dependence of spin-up torque on channel and gas properties. Chapter 3 studies the theory of super fluid plug operation. And chapter 4 studies the gyro rotor and housing manufacture

    Infrared telescope

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    The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described

    Spin vector control for a spinning space station. Volume 2 - Analytic manual Final report

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    Computer manual for calculating dynamic vector control of dual spin space statio
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