35,967 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-PĆ©rot accelerometer
A mechanically amplified Fabry-PeĢrot optical accelerometer is reported in which photothermal actuation is used to calibrate the in-phase and quadrature (I&Q) readout. The Fabry-PeĢrot 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 (Ī» = 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 2Ļ-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 Ī¼m, and angle 2 Ā° 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 Ī¼g/āHz 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
Horseshoes and Arnold Diffusion for Hamiltonian Systems on Lie Groups
Abstract not availabl
Overview of the Tevatron Collider Complex: Goals, Operations and Performance
For more than two decades the Tevatron proton-antiproton collider was the
centerpiece of the world's high energy physics program. The collider was
arguably one of the most complex research instruments ever to reach the
operation stage and is widely recognized for numerous physics discoveries and
for many technological breakthroughs. In this article we outline the historical
background that led to the construction of the Tevatron Collider, the strategy
applied to evolution of performance goals over the Tevatron's operational
history, and briefly describe operations of each accelerator in the chain and
achieved performance.Comment: Includes modifications suggested by reviewer
MetaboNetworks, an interactive Matlab-based toolbox for creating, customizing and exploring sub-networks from KEGG.
Summary: MetaboNetworks is a tool to create custom sub-networks in Matlab using main reaction pairs as defined by the Kyoto Encyclopaedia of Genes and Genomes and can be used to explore transgenomic interactions, for example mammalian and bacterial associations. It calculates the shortest path between a set of metabolites (e.g. biomarkers from a metabonomic study) and plots the connectivity between metabolites as links in a network graph. The resulting graph can be edited and explored interactively. Furthermore, nodes and edges in the graph are linked to the Kyoto Encyclopaedia of Genes and Genomes compound and reaction pair web pages. Availability and implementation: MetaboNetworks is available from http://www.mathworks.com/matlabcentral/fileexchange/42684. Contact: [email protected] or [email protected] Supplementary information: Supplementary data are available at Bioinformatics online
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