35,690 research outputs found
Special tool kit aids heavily garmented workers
Triangular aluminum tool kit, filled with polyurethane is constructed to receive various tools and hold them in a snug but quick-release fit as an aid to heavily gloved workers. The kit is designed to allow mounting within easily accessable reach and to provide protection of the tools during storage
Remote photothermal actuation for calibration of in-phase and quadrature readout in a mechanically amplified Fabry-Pérot accelerometer
A mechanically amplified Fabry-Pérot optical accelerometer is reported in which photothermal actuation is used to calibrate the in-phase and quadrature (I&Q) readout. The Fabry-Pérot interferometer (FPI) is formed between a gold-coated silicon mirror, situated in the middle of a V-beam amplifier, and the end surface of a cleaved optical fiber. On the opposite side of the silicon mirror, a further cleaved optical fiber transmits near-infrared laser light (λ = 785 nm), which is absorbed by the uncoated silicon causing heating. The thermal expansion of the V-beam is translated into an amplified change in cavity length of the FPI, large enough for the 2π-phase variation necessary for I&Q calibration. A simple 1D thermal analysis of the structure has been developed to predict the relationship between laser power and change in cavity length. A device having a V-beam of length 1.8 mm, width 20 μm, and angle 2 ° was found to undergo a cavity length change of 785 nm at 30 mW input power. The device response was approximately linear for input accelerations from 0.01 to 15 g. The noise was measured to be ~ 60 μg/√Hz from 100 Hz to 3.0 kHz, whereas the limit of detection was 47.7 mg from dc to 3.0 kHz
Examining and contrasting the cognitive activities engaged in undergraduate research experiences and lab courses
While the positive outcomes of undergraduate research experiences (UREs) have
been extensively categorized, the mechanisms for those outcomes are less
understood. Through lightly structured focus group interviews, we have
extracted the cognitive tasks that students identify as engaging in during
their UREs. We also use their many comparative statements about their
coursework, especially lab courses, to evaluate their experimental
physics-related cognitive tasks in those environments. We find there are a
number of cognitive tasks consistently encountered in physics UREs that are
present in most experimental research. These are seldom encountered in lab or
lecture courses, with some notable exceptions. Having time to reflect and fix
or revise, and having a sense of autonomy, were both repeatedly cited as key
enablers of the benefits of UREs. We also identify tasks encountered in actual
experimental research that are not encountered in UREs. We use these findings
to identify opportunities for better integration of the cognitive tasks in UREs
and lab courses, as well as discussing the barriers that exist. This work
responds to extensive calls for science education to better develop students'
scientific skills and practices, as well as calls to expose more students to
scientific research.Comment: 11 pages, 3 figure
A carbon dioxide reduction unit using Bosch reaction and expendable catalyst cartridges
Catalytic carbon dioxide reduction cartridge for oxygen recovery in life support systems of long term manned space flight
Bosch CO2 Reduction System Development
Development of a Bosch process CO2 reduction unit was continued, and, by means of hardware modifications, the performance was substantially improved. Benefits of the hardware upgrading were demonstrated by extensive unit operation and data acquisition in the laboratory. This work was accomplished on a cold seal configuration of the Bosch unit
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