1,038 research outputs found
Analysis and study of hospital communication via social media from the patient perspective
Currently, the online interaction between citizens and hospitals is poor, as
users believe that there are shortcomings that could be improved. This study
analyzes patients’ opinions of the online communication strategies of hospitals in
Spain. Therefore, a mixed-method is proposed. Firstly, a qualitative analysis through
a focus-group was carried out, so around twenty representatives of national,
regional and local patients’ associations were brought together. Secondly, the
research is supplemented with a content assessment of the Twitter activity of the
most influential hospitals in Spain. The results reveal that the general public
appreciate hospitals’ communication potential through social media, although they
are generally unaware of how it works. The group says that, apart from the lack of
interaction, they find it hard to understand certain messages, and some publications
give a biased picture. In order to improve communication, patients and
relatives are demanding that their perspective be taken into consideration in the
messages issued to enhance the quality of life and well-being of society
Strong Optomechanical Squeezing of Light
We create squeezed light by exploiting the quantum nature of the mechanical
interaction between laser light and a membrane mechanical resonator embedded in
an optical cavity. The radiation pressure shot noise (fluctuating optical force
from quantum laser amplitude noise) induces resonator motion well above that of
thermally driven motion. This motion imprints a phase shift on the laser light,
hence correlating the amplitude and phase noise, a consequence of which is
optical squeezing. We experimentally demonstrate strong and continuous
optomechanical squeezing of 1.7 +/- 0.2 dB below the shot noise level. The peak
level of squeezing measured near the mechanical resonance is well described by
a model whose parameters are independently calibrated and that includes thermal
motion of the membrane with no other classical noise sources.Comment: 12 pages, 8 figure
Topography Experiment (TOPEX) Software Document Series Volume 7: TOPEX Mission Radar Altimeter Engineering Assessment Report, February 1994
This document describes the GSFC/WFF analysis of the on-orbit engineering data from the TOPEX radar altimeter, to establish altimeter performance. In accordance with Project guidelines, neither surface truth nor precision orbital data are used for the engineering assessment of the altimeter. The use of such data would imply not only a more intensive and complete performance evaluation, but also a calibration. Such evaluations and.calibrations are outside the scope of this document and will be presented in a separate Verification Report
Control of Material Damping in High-Q Membrane Microresonators
We study the mechanical quality factors of bilayer aluminum/silicon-nitride
membranes. By coating ultrahigh-Q Si3N4 membranes with a more lossy metal, we
can precisely measure the effect of material loss on Q's of tensioned resonator
modes over a large range of frequencies. We develop a theoretical model that
interprets our results and predicts the damping can be reduced significantly by
patterning the metal film. Using such patterning, we fabricate Al-Si3N4
membranes with ultrahigh Q at room temperature. Our work elucidates the role of
material loss in the Q of membrane resonators and informs the design of hybrid
mechanical oscillators for optical-electrical-mechanical quantum interfaces
Cavity optomechanics with Si3N4 membranes at cryogenic temperatures
We describe a cryogenic cavity-optomechanical system that combines Si3N4
membranes with a mechanically-rigid Fabry-Perot cavity. The extremely high
quality-factor frequency products of the membranes allow us to cool a MHz
mechanical mode to a phonon occupation of less than 10, starting at a bath
temperature of 5 kelvin. We show that even at cold temperatures
thermally-occupied mechanical modes of the cavity elements can be a limitation,
and we discuss methods to reduce these effects sufficiently to achieve ground
state cooling. This promising new platform should have versatile uses for
hybrid devices and searches for radiation pressure shot noise.Comment: 19 pages, 5 figures, submitted to New Journal of Physic
Tunable Cavity Optomechanics with Ultracold Atoms
We present an atom-chip-based realization of quantum cavity optomechanics
with cold atoms localized within a Fabry-Perot cavity. Effective sub-wavelength
positioning of the atomic ensemble allows for tuning the linear and quadratic
optomechanical coupling parameters, varying the sensitivity to the displacement
and strain of a compressible gaseous cantilever. We observe effects of such
tuning on cavity optical nonlinearity and optomechanical frequency shifts,
providing their first characterization in the quadratic-coupling regime.Comment: 4 pages, 5 figure
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