1,721,095 research outputs found
DIRECT NEAR-FIELD ANTENNA TESTING AND FAULT DIAGNOSIS BY A SYLICON-PROBE-BASED OPTICAL SENSING TECHNIQUE
No full textDIRECT NEAR-FIELD ANTENNA TESTING AND FAULT DIAGNOSIS BY A SYLICON-PROBE-BASED OPTICAL SENSING TECHNIQUE
No full textDIRECT NEAR-FIELD ANTENNA TESTING AND FAULT DIAGNOSIS BY A SYLICON-PROBE-BASED OPTICAL SENSING TECHNIQUE
No full textPeriodic versus aperiodic: Enhancing the sensitivity of porous silicon based optical sensors
No full textThe authors have compared the sensitivities of resonant optical biochemical sensors, based on both periodic and aperiodic porous silicon structures, such as the Bragg and the Thue-Morse multilayer. The shifts of the reflectivity spectra of these devices on exposure to several chemical compounds have been measured: the aperiodic multilayer is more sensitive than the periodic one. Adopting a simple theoretical model of the optical response of devices, they inferred that the aperiodic structure provide a higher filling capability with respect to the periodic one, due to the lower number of interfaces
Quantitative optical sensing in two-component mixtures using porous silicon microcavities
No full textPolarimetric approach for well-defined impurities detection in isotropic materials
No full textIn this paper, a new kind of approach to reveal the presence of well-defined impurities in isotropic materials is proposed and verified against actual measurements over real samples. The rationale lies in the different polarimetric symmetry properties of inhomogeneous and isotropic materials within well-defined impurities from homogeneous ones. The underpinning physical idea is to inspect the Mueller matrix of the material sample, obtained from an ellipsometric measure: its form, in terms of symmetry, can reveal whether or not if in there are well-defined impurities in the sample
Modelling of debris flows and flash floods propagation: a case study from Italian Alps
No full textStorage basins, check dams, barriers and other control works are often used to reduce threats and damage from flow-like mass movements. This paper deals with the effectiveness of two storage basins of the Italian Alps against debris flows followed by a flash flood induced by short heavy rainfall in 2009. Referring to detailed field data, the propagation of flows and their interaction with the control works are analysed by using an advanced numerical depth-averaged flow propagation model based on SPH (Smooth Particle Hydrodynamics) technique. The Froude dynamic similitude is here used to provide a quantitative descriptor of the dynamic features of the flows. The numerical results show that debris flows accumulated in the storage basins since they propagated downslope like subcritical flows. On the contrary, flash floods overpassed the control works having moved along the entire path as supercritical flows. Those findings are fully supported by some previous studies and provide a further contribution to the relevant topic of granular flow-obstacle interaction
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