3,062 research outputs found
Circular Dichroism of RbHe and RbN Molecules
We present measurements of the circular dichroism of optically pumped Rb
vapor near the D1 resonance line. Collisions with the buffer gases He and
N reduce the transparency of the vapor, even when fully polarized. We use
two methods to measure this effect, show that the He results can be understood
from RbHe potential curves, and show how this effect conspires with the
spectral profile of the optical pumping light to increase the laser power
demands for optical pumping of very optically thick samples
Postcard: 28. Tultenango Earthenware. Mexico
This black and white photographic postcard features a collection of earthenware for sale. There are four people in the background under a canopy and they each hold a piece of pottery. There are two rows of pottery in the foreground with some items stacked three high. Printed text is on the bottom of the card. Handwriting is on the back of the card.https://scholars.fhsu.edu/tj_postcards/1833/thumbnail.jp
An analysis of pilot error-related aircraft accidents
A multidisciplinary team approach to pilot error-related U.S. air carrier jet aircraft accident investigation records successfully reclaimed hidden human error information not shown in statistical studies. New analytic techniques were developed and applied to the data to discover and identify multiple elements of commonality and shared characteristics within this group of accidents. Three techniques of analysis were used: Critical element analysis, which demonstrated the importance of a subjective qualitative approach to raw accident data and surfaced information heretofore unavailable. Cluster analysis, which was an exploratory research tool that will lead to increased understanding and improved organization of facts, the discovery of new meaning in large data sets, and the generation of explanatory hypotheses. Pattern recognition, by which accidents can be categorized by pattern conformity after critical element identification by cluster analysis
Marjorie Shiels (née Collins) 1895-1970: Pioneering Ecologist
The current study aims to evaluate and empirically investigate Prinstein's (2007) conclusions regarding expert nominators, a subsample of individuals in a peer group whose peer nominations might substitute for nominations from the full sample. The current study empirically identified experts based on comparative accuracy, the extent to which each participant's nominations matched full sample nominations across items. Eighth-graders at two schools (Ns = 273 and 334) completed 16 nomination items. Participants were labeled experts if they showed above-average comparative accuracy on at least 75% of items; however, expert nominations were neither highly internally reliable nor valid. Nominations from experts would not have adequately substituted for collecting full-sample nominations. Future research may possibly benefit from identifying more limited, single-item experts
Breakdown of Angular Momentum Selection Rules in High Pressure Optical Pumping Experiments
We present measurements, using two complementary methods, of the breakdown of
atomic angular momentum selection rules in He-broadened Rb vapor. Atomic dark
states are rendered weakly absorbing due to fine-structure mixing during Rb-He
collisions. The effect substantially increases the photon demand for optical
pumping of dense vapors
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