7,872 research outputs found
Dementia in low-income and middle-income countries: Different realities mandate tailored solutions
CNPq (a Brazilian public agency)Univ Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilChristian Med Coll & Hosp, Dept Psychiat, Vellore, Tamil Nadu, IndiaUniv Fed Sao Paulo, Dept Psychobiol, Sao Paulo, BrazilCNPq: 311031/2016-1Web of Scienc
Electron-phonon coupling in Ti/TiN MKIDs multilayer microresonator
Over the last few years there has been a growing interest toward the use of
superconducting microwave microresonators operated in quasi-thermal equilibrium
mode, especially applied to single particle detection. Indeed, previous devices
designed and tested by our group with X-ray sources in the keV range evidenced
that several issues arise from the attempt of detection through athermal
quasiparticles produced within direct strikes of X-rays in the superconductor
material of the resonator. In order to prevent issues related to quasiparticles
self-recombination and to avoid exchange of athermal phonons with the
substrate, our group focused on the development of thermal superconducting
microresonators. In this configuration resonators composed of multilayer films
of Ti/TiN sense the temperature of an absorbing material. To maximize the
thermal response, low critical temperature films are preferable. By lowering
the critical temperature, though, the maximum probing power bearable by the
resonators decrease abruptly because of the weakening of the electron-phonon
coupling. A proper compromise has to be found in order to avoid signal to noise
ratio degradation. In this contribution we report the latest measurement of the
electron-phonon coupling
Particle sizing in non-dilute dispersions using diffusing wave spectroscopy with multiple optical path lengths
Non-dilute dispersed phase systems, such as foams, emulsions, and suspensions, are an important class of final formulations and chemical process intermediates in a variety of industries. The utility of these systems hinges on their stability over the lifetime of use, and therefore an accurate assessment of chemical and physical dynamics, asformulated, is required. We describe a unified treatment of diffusing wave spectroscopy (DWS) data using a range of optical path length with a goniometric instrument. DWS correlation data from multiple angles and robust Monte Carlo simulations are used to determine accurate values of the photon transport mean free path length. The variance on each correlation function is used to determine the physical time range that the mean squared displacement can be analyzed. Using standard solid particle suspensions of polystyrene and SiO2, we determine the average particle size with accuracy comparable to dynamic light scattering
Development of microwave superconducting microresonators for neutrino mass measurement in the HOLMES framework
The European Research Council has recently funded HOLMES, a project with the
aim of performing a calorimetric measurement of the electron neutrino mass
measuring the energy released in the electron capture decay of 163Ho. The
baseline for HOLMES are microcalorimeters coupled to Transition Edge Sensors
(TESs) read out with rf-SQUIDs, for microwave multiplexing purposes. A
promising alternative solution is based on superconducting microwave
resonators, that have undergone rapid development in the last decade. These
detectors, called Microwave Kinetic Inductance Detectors (MKIDs), are
inherently multiplexed in the frequency domain and suitable for even
larger-scale pixel arrays, with theoretical high energy resolution and fast
response. The aim of our activity is to develop arrays of microresonator
detectors for X-ray spectroscopy and suitable for the calorimetric measurement
of the energy spectra of 163Ho. Superconductive multilayer films composed by a
sequence of pure Titanium and stoichiometric TiN layers show many ideal
properties for MKIDs, such as low loss, large sheet resistance, large kinetic
inductance, and tunable critical temperature . We developed Ti/TiN
multilayer microresonators with within the range from 70 mK to 4.5 K and
with good uniformity. In this contribution we present the design solutions
adopted, the fabrication processes and the characterization results
Linking the actors and policies throughout the disaster management cycle by "Agreement on Objectives" – a new output-oriented management approach
Current management of disaster risks is often fragmented due to a lack of coordination between involved actors, i.e. civil protection and spatial planning – a phenomenon which is known as the "problem of interplay". This paper presents an output-oriented risk management approach ("parametric governance"). Here, the modality of the achievement of objectives remains in the hands of the given addressees. This implies a shift from a top-down to a more collaborative, process-oriented form of decision-making. The approach has been successfully applied in two hazard cases and three administrative contexts: (a) the City of Dortmund (Germany) facing flash floods, (b) East Attica region (Greece) facing forest fires, and (c) Lazio Region (Italy) also facing forest fires. As proved by the applications of the concept, a dialogue among experts, stakeholders, and decision-makers is indispensable in order to guarantee inclusion of all diverse and competing values, opinions, and claims. Moreover, a structured communication path is needed to meet the requirements of a risk governance process. Finally, a win-win-situation among the involved actors has to be created to reach an agreement on common goals and actions to achieve them in due time
Persistent topology for natural data analysis - A survey
Natural data offer a hard challenge to data analysis. One set of tools is
being developed by several teams to face this difficult task: Persistent
topology. After a brief introduction to this theory, some applications to the
analysis and classification of cells, lesions, music pieces, gait, oil and gas
reservoirs, cyclones, galaxies, bones, brain connections, languages,
handwritten and gestured letters are shown
Continuous feedback on a quantum gas coupled to an optical cavity
We present an active feedback scheme acting continuously on the state of a
quantum gas dispersively coupled to a high-finesse optical cavity. The quantum
gas is subject to a transverse pump laser field inducing a self-organization
phase transition, where the gas acquires a density modulation and photons are
scattered into the resonator. Photons leaking from the cavity allow for a
real-time and non-destructive readout of the system. We stabilize the mean
intra-cavity photon number through a micro-processor controlled feedback
architecture acting on the intensity of the transverse pump field. The feedback
scheme can keep the mean intra-cavity photon number constant, in
a range between and , and
for up to 4 s. Thus we can engage the stabilization in a regime where the
system is very close to criticality as well as deep in the self-organized
phase. The presented scheme allows us to approach the self-organization phase
transition in a highly controlled manner and is a first step on the path
towards the realization of many-body phases driven by tailored feedback
mechanisms
Delocalization and the semiclassical description of molecular rotation
We discuss phase-space delocalization for the rigid rotator within a
semiclassical context by recourse to the Husimi distributions of both the
linear and the anisotropic instances. Our treatment is based upon the
concomitant Fisher information measures. The pertinent Wehrl entropy is also
investigated in the linear case.Comment: 6 pages, 3 figure
Fabrication of high-resolution strain sensors based on wafer-level vacuum packaged MEMS resonators
The paper reports on the fabrication and characterization of high-resolution strain sensors for structural materials based on Silicon On Insulator flexural resonators manufactured by polysilicon Low-Pressure Chemical Vapour Deposition vacuum packaging. The sensors present sensitivity of 164 Hz/με and strain resolution limit of 150 pε on steel for a measurement time of 315 ms, in both tensile and compressive strain regimes. The readout of the sensor is implemented with a transimpedance oscillator circuit implemented on Printed Circuit Board, in which a microcontroller-based reciprocal frequency counter is integrated. The performance of the sensors on steel are investigated for measurement bandwidths from 1.5 to 500 Hz and a comparison with conventional metal strain gauges is proposed.The contribution of Mr. Filippo Bonafè, Mr. Fabrizio Tamarri, Mr. Michele Sanmartin and Mr. Giulio Pizzochero in the clean room processing employed for the manufacturing of the MEMS sensors is acknowledged. The contribution of Dr. Michele Bellettato in sample preparation is also acknowledged.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.sna.2016.01.00
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