5,834 research outputs found
Sensitivity-bandwidth limit in a multi-mode opto-electro-mechanical transducer
An opto--electro--mechanical system formed by a nanomembrane capacitively
coupled to an LC resonator and to an optical interferometer has been recently
employed for the high--sensitive optical readout of radio frequency (RF)
signals [T. Bagci, \emph{et~al.}, Nature {\bf 507}, 81 (2013)]. Here we propose
and experimentally demonstrate how the bandwidth of such kind of transducer can
be increased by controlling the interference between two--electromechanical
interaction pathways of a two--mode mechanical system. With a
proof--of--principle device \new{operating at room temperature, we achieve a
sensitivity of 300 nV/Hz^(1/2) over a bandwidth of 15 kHz in the presence of
radiofrequency noise, and an optimal shot-noise limited sensitivity of 10
nV/Hz^(1/2) over a bandwidth of 5 kHz. We discuss strategies for improving the
performance of the device, showing that, for the same given sensitivity, a
mechanical multi--mode transducer can achieve a bandwidth} significantly larger
than that of a single-mode one
Drinking wine at home: Hedonic analysis of sicilian wines using quantile regression
Abstract: In recent decades, the Sicilian wine industry has experienced a booming expansion because of the growing preferences of Italian consumers for Sicilian wines, especially in extra-regional markets. These consumers have been paying closer attention to Sicilian premium wines.
For this reason, the objective of this study is to inform professional investors and wine managers about the consumer preferences with respect to the most important segment categories of domestically consumed Sicilian wines. Using the quantile regression technique, we analyzed the
role of wine attributes and prices as an information tool in order to value for each wine segment the implicit price of the attributes affecting wine consumers\u2019 choices. The results indicate that Protected Designation of Origin (PDO) and Geographical Indication (PGI) certification is the main determinant in the wine price mechanisms and certified wines achieve premium prices that are progressively higher as the price level of the wine increases. Furthermore the effect of the brand on price formation seems to have a significant impact for low-end wines, whereas it has no specific impact on the price mechanism for high-end wines.
Keywords: Consumer Scan Dataset, Geographic Origin, Hedonic Price, Robust Regression, Wine Consumptio
Estimation of the methane emission factor for the Italian Mediterranean buffalo
In order to contribute to the improvement of the national greenhouse gas emission inventory, this work aimed at estimating a country-specific enteric methane (CH4) emission factor for the Italian Mediterranean buffalo. For this purpose, national agriculture statistics, and information on animal production and farming conditions were analysed, and the emission factor was estimated using the Tier 2 model of the Intergovernmental Panel on Climate Change. Country-specific CH4 emission factors for buffalo cows (630 kg body weight, BW) and other buffalo (313 kg BW) categories were estimated for the period 1990–2004. In 2004, the estimated enteric CH4 emission factor for the buffalo cows was 73 kg/head per year, whereas that for other buffalo categories it was 56 kg/head per year. Research in order to determine specific CH4 conversion rates at the predominant production system is suggested
Simone Waldt and Klaus Woertler (Eds): Measurements and Classifications in Musculoskeletal Radiology
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Quantum dynamics of a vibrational mode of a membrane within an optical cavity
Optomechanical systems are a promising candidate for the implementation of
quantum interfaces for storing and redistributing quantum information. Here we
focus on the case of a high-finesse optical cavity with a thin vibrating
semitransparent membrane in the middle. We show that robust and stationary
optomechanical entanglement could be achieved in the system, even in the
presence of nonnegligible optical absorption in the membrane. We also present
some preliminary experimental data showing radiation-pressure induced optical
bistability.Comment: 6 pages, 2 figures. Work presented at the conference QCMC 2010 held
on 19-23 July 2010 at the University of Queensland, Brisbane, Australi
Quantum dynamics of a high-finesse optical cavity coupled with a thin semi-transparent membrane
We study the quantum dynamics of the cavity optomechanical system formed by a
Fabry-Perot cavity with a thin vibrating membrane at its center. We first
derive the general multimode Hamiltonian describing the radiation pressure
interaction between the cavity modes and the vibrational modes of the membrane.
We then restrict the analysis to the standard case of a single cavity mode
interacting with a single mechanical resonator and we determine to what extent
optical absorption by the membrane hinder reaching a quantum regime for the
cavity-membrane system. We show that membrane absorption does not pose serious
limitations and that one can simultaneously achieve ground state cooling of a
vibrational mode of the membrane and stationary optomechanical entanglement
with state-of-the-art apparatuses.Comment: 14 pages, 7 figure
Promoting health equity through social capital in deprived communities: a natural policy experiment in Trieste, Italy
Optomechanical sideband cooling of a thin membrane within a cavity
We present an experimental study of dynamical back-action cooling of the
fundamental vibrational mode of a thin semitransparent membrane placed within a
high-finesse optical cavity. We study how the radiation pressure interaction
modifies the mechanical response of the vibrational mode, and the experimental
results are in agreement with a Langevin equation description of the coupled
dynamics. The experiments are carried out in the resolved sideband regime, and
we have observed cooling by a factor 350 We have also observed the mechanical
frequency shift associated with the quadratic term in the expansion of the
cavity mode frequency versus the effective membrane position, which is
typically negligible in other cavity optomechanical devices.Comment: 15 pages, 7 figure
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