360 research outputs found
Transient Study of a Cryogenic Hydrogen Filling System
An investigation was made of producing a workable model for the transient analysis of a cryogenic hydrogen filling system. A series of programs and subprograms defining the momentum, mass, and energy balances and the physical properties, transport properties, and their interactions were devised.The program was modified for a simple theoretical test fluid. Exhaustive runs and modifications were made and at this point no stability was achieved except in trivial cases
Implementation of Cavity Squeezing of a Collective Atomic Spin
We squeeze unconditionally the collective spin of a dilute ensemble of
laser-cooled rubidium-87 atoms using their interaction with a driven optical
resonator. The shape and size of the resulting spin uncertainty region are well
described by a simple analytical model [M.H.S., I.D.L., V.V., arXiv:0911.3936]
through two orders of magnitude in the effective interaction strength, without
free parameters. We deterministically generate states with up to 5.6(6) dB of
metrologically relevant spin squeezing on the canonical rubidium-87 hyperfine
clock transition.Comment: 4 pages, 2 figures. To be published in Phys. Rev. Lett. Some
additional details and clarified wording in response to referee comments.
Figures and results unchange
Correlation of leak rates of various fluids with the leak rate of an inert gas in the same configuration
NASA is interested in field testing for possible leakage in their fueling systems; however, many fuels are hazardous to the extent that personnel cannot be on hand when the system is being monitored. It is proposed that an inert material such as helium be used on the field test, and that those results be calibrated to simulate the actual process. A technique such as this would allow personnel to be on site during the testing and use techniques to determine the behavior of the system that could not be used otherwise. This endeavor attempts to develop such a correlation. The results show promise, but more refinement and data are needed
Squeezing the Collective Spin of a Dilute Atomic Ensemble by Cavity Feedback
We propose and analyze a simple method to squeeze dynamically and
unconditionally the collective spin of a dilute atomic ensemble by interaction
with a driven mode of an optical resonator, as recently demonstrated [I. D. L.,
M. H. S., and V. V., Phys. Rev. Lett. 104, 073602 (2010)]. We show that
substantial squeezing can be achieved in the regime of strong collective
ensemble-resonator coupling. The squeezing is ultimately limited either by
photon emission into free space or by the curvature of the Bloch sphere. We
derive both limits and show where each prevails.Comment: 4 pages, 2 figures. Minor revision. To appear in Phys. Rev.
The Effect of Integration: A Study on the Impact of Diversity on Economic Indicators
This paper examines the effect of diversity, measured by the dissimilarity index, on the economic strength of an area. Economic strength is measured using five economic indicators: median home value, median income, median gross rent, percentage of people with health insurance, and firms per capita. The work aims to show that there is a positive economic impact due to integrating and creating communities that are more diverse. Previous work shows there is a positive impact of diversity on economic indicators such as wages, rents, and production but previous studies do not look at the effect on these economic indicators. This study looks at 1,246 cities across the United States and the District of Columbia in 2015 and measures the effect of diversity on economic strength using an ordinary least squares (OLS) regression. The paper finds that there are varying degrees of significance depending on the economic indicator and racial group
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