9,380 research outputs found
Field trips and resource visitors available to the Natick, Massachusetts elementary schools
Thesis (Ed.M.)--Boston Universit
Portable digital pressure indicator for calibrating magnetic tape recorders
The design of a portable Digital Pressure Indicator (DPI) to be used for calibrating the pressure systems on Langley's magnetic tape recorders is described. High-speed magnetic tape recorders require pressure (0 to 20 psig) for providing an air cushion across the tape guides and a slight vacuum (30 inch H2O) for maintaining the proper number of tape loops in the advance and feed chamber. The DPI is a hand-held device that can be quickly coupled to a magnetic tape recorder and includes a two-position switch for selecting either measured pressure or vacuum, to be displayed digitally in engineering units (psig or inches H2O). The DPI is currently in use in Langley's Analysis and Computation Division
The contribution of multi-sensory aids to a meaningful art program.
Thesis (Ed.M.)--Boston Universit
- …