137,963 research outputs found
Does drying affect gel networks?
The properties of low molecular weight gels are determined by the underlying, self-assembled network. To access information on the network, it is common for techniques to be used that require the gel to be dried, such as transmission electron microscopy or scanning electron microscopy. The implicit assumption is that this drying has no bearing on the data collected. Here, we discuss the validity of this assumption
Simulator study of a flight director display
A six degree of freedom, fixed base simulation study of the use of a flight director by general aviation pilots in an instrument landing system approach was conducted. An autopilot command law was used to drive the flight director needles. Time histories of the pilot aircraft display system responses and standard deviations and means of the glide slope and localizer errors were obtained. The pilot aircraft display system responses with the flight director were very similar to the autopilot aircraft responses. Without the flight director, the pilot aircraft display system exhibited less damping than with the flight director. The sensitivity of the flight director command laws was judged to be about as high as it could be by the test subjects. Thus, further improvement in the pilot aircraft display system performance by increasing the gains in the command laws was precluded
Goalposts on the Move
The impact profile of recent UK geoscience
research is set to change, say Nick Petford
& Jonathan Adam
Apollo experience report: Problem reporting and corrective action system
The Apollo spacecraft Problem Reporting and Corrective Action System is presented. The evolution from the early system to the present day system is described. The deficiencies and the actions taken to correct them are noted, as are management controls for both the contractor and NASA. Significant experience gained from the Apollo Problem Reporting and Corrective Action System that may be applicable to future manned spacecraft is presented
Geological remote sensing: Identification and mapping of rock types for non-renewable resources
Efforts concentrated on developing a technique for relating laboratory spectral reflectance curves of known rocks and vegetation on LANDSAT multispectral images. The techniques involves determination of the laboratory spectral signature of a material of interest and searching a stack of spatially registered multispectral images for materials with the desired spectral signature. Changes in spectral reflectance caused by vegetation cover were also investigated in surface samples from Hawaii
Helicopter technology benefits and needs. Volume 2: Appendices
Vehicle design, avionics and flight systems; safety and reliability; navigation, guidance and flight control; propulsion; auxiliary systems; human factors; and monitoring and diagnostic systems are the technology areas involved in solving operational and technical problems related to the use of helicopters. Tables show the problems encountered and the proposed research and technology for helicopter use for search and rescue; emergency medical services; law enforcement; environmental control; fire fighting; and resource management
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