34,645 research outputs found
Transformation of scientists and engineers into managers
The purposes of this research were to determine the principal problems and obstacles faced by specialists during the transition period when they are becoming managers, and to discover ways by which their difficulties might be avoided or overcome. It was found that senior management officials are unaware--or tend to ignore the importance--of the transition process and its problems, that little attention has been given to developing management training to overcome transition problems, and that much of the training which is offered is largely irrelevant to these problems
Experimental performance of an ablative material as an external insulator for a hypersonic research aircraft
An ablative material composed of silica-filled elastomeric silicone was tested to evaluate its thermal and structural performance as an external insulator, or heat shield, for a hypersonic research aircraft. The material was also tested to determine whether it would form a durable char layer when initially heated and thereafter function primarily as an insulator with little further pyrolysis or char removal. Aerothermal tests were representative of nominal Mach 6 cruise conditions of the aircraft, and additional tests were representative of Mach 8 cruise and interference heating conditions. Radiant heating tests were used to simulate the complete nominal Mach 6 surface-temperature history. The silica char that formed during aerothermal tests was not durable. The char experienced a general and preferential surface recession, with the primary mechanism for char removal being erosion. Tests revealed that radiant heating is not a valid technique for simulating aerodynamic heating of the material
Development and Verification of a Flight Stack for a High-Altitude Glider in Ada/SPARK 2014
SPARK 2014 is a modern programming language and a new state-of-the-art tool
set for development and verification of high-integrity software. In this paper,
we explore the capabilities and limitations of its latest version in the
context of building a flight stack for a high-altitude unmanned glider. Towards
that, we deliberately applied static analysis early and continuously during
implementation, to give verification the possibility to steer the software
design. In this process we have identified several limitations and pitfalls of
software design and verification in SPARK, for which we give workarounds and
protective actions to avoid them. Finally, we give design recommendations that
have proven effective for verification, and summarize our experiences with this
new language
Economic comparison of fabric filters and electrostatic precipitators for particulate control on coal-fired utility boilers
The uncertainties and associated costs involved in selecting and designing a particulate control device to meet California's air emission regulations are considered. The basic operating principles of electrostatic precipitators and fabric filters are discussed, and design parameters are identified. The size and resulting cost of the control device as a function of design parameters is illustrated by a case study for an 800 MW coal-fired fired utility boiler burning a typical southwestern subbituminous coal. The cost of selecting an undersized particulate control device is compared with the cost of selecting an oversized device
Asteroid selection for mission opportunities
A study to assess the present state of knowledge of asteroids as well as the rate of change of that knowledge to better identify the mission and target priorities for advanced planning of asteroidal flights in the 1980's is presented. Topics discussed include; the present state of asteroid knowledge, the scientific goals and priorities attached to asteroid exploration, the anticipated advances in knowledge over the current decade, asteroid mission consideration, and asteroid selection. Data sheets for 118 asteroids are contained. These are asteroids for which some data is available over and above orbital parameters and magnitude
Facilitating Humanitarian Access to Pharmaceutical and Agricultural Innovation
Calls for intellectual property licensing strategies in the pharmaceutical and agricultural sectors that promote humanitarian access to product innovations for the benefit of the disadvantaged. Includes profiles of successful and promising strategies
S-band antenna phased array communications system
The development of an S-band antenna phased array for spacecraft to spacecraft communication is discussed. The system requirements, antenna array subsystem design, and hardware implementation are examined. It is stated that the phased array approach offers the greatest simplicity and lowest cost. The objectives of the development contract are defined as: (1) design of a medium gain active phased array S-band communications antenna, (2) development and test of a model of a seven element planar array of radiating elements mounted in the appropriate cavity matrix, and (3) development and test of a breadboard transmit/receive microelectronics module
Retransmission of water resources data using the ERTS-1 data collection system
There are no author-identified significant results in this report
A Program of Photometric Measurements of Solar Irradiance Fluctuations from Ground-based Observations
Photometric observations of the sun have been carried out at the San Fernando Observatory since early 1985. Since 1986, observations have been obtained at two wavelengths in order to separately measure the contributions of sunspots and bright facular to solar irradiance variations. Researchers believe that the contributions of sunspots can be measured to an accuracy of about plus or minus 30 ppm. The effect of faculae is much less certain, with uncertainties in the range of plus or minus 300 ppm. The larger uncertainty for faculae reflects both the greater difficulty in measuring the facular area, due to their lower contrast compared to sunspots, and the greater uncertainty in their contrast variation with viewing angle on the solar disk. Recent results from two separate photometric telescopes will be compared with bolometric observations from the active cavity radiometer irradiance monitor (ACRIM) that was on board the Solar Max satellite
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