All Optical Switch of Vacuum Rabi Oscillations: The Ultrafast Quantum Eraser

We study the all-optical time-control of the strong coupling between a single cascade three-level quantum emitter and a microcavity. We find that only specific arrival-times of the control pulses succeed in switching-off the Rabi oscillations. Depending on the arrival times of control pulses, a variety of exotic non-adiabatic cavity quantum electrodynamics effects can be observed. We show that only control pulses with specific arrival times are able to suddenly switch-off and -on first-order coherence of cavity photons, without affecting their strong coupling population dynamics. Such behavior may be understood as a manifestation of quantum complementarity

Towards formal models and languages for verifiable Multi-Robot Systems

Incorrect operations of a Multi-Robot System (MRS) may not only lead to unsatisfactory results, but can also cause economic losses and threats to safety. These threats may not always be apparent, since they may arise as unforeseen consequences of the interactions between elements of the system. This call for tools and techniques that can help in providing guarantees about MRSs behaviour. We think that, whenever possible, these guarantees should be backed up by formal proofs to complement traditional approaches based on testing and simulation. We believe that tailored linguistic support to specify MRSs is a major step towards this goal. In particular, reducing the gap between typical features of an MRS and the level of abstraction of the linguistic primitives would simplify both the specification of these systems and the verification of their properties. In this work, we review different agent-oriented languages and their features; we then consider a selection of case studies of interest and implement them useing the surveyed languages. We also evaluate and compare effectiveness of the proposed solution, considering, in particular, easiness of expressing non-trivial behaviour.Comment: Changed formattin

Dispersion in two-dimensional turbulent buoyant plumes

Using high-resolution imaging and dye studies, we investigate experimentally the mixing of a tracer by the eddies within a two-dimensional turbulent buoyant plume. Instantaneously, the plume consists of a series of eddies, and at each point along the centreline of the plume, the along-plume speed of the leading edge of the eddies $w_{e}\approx 1.3f^{1/3}$, where $f$ is the buoyancy flux, while the product of the length scale, $A$, and frequency, ${\it\omega}$, of the eddies ${\it\omega}A\approx 0.15f^{1/3}$. The circulation and flow associated with the eddies lead to longitudinal mixing relative to the mean flow. To illustrate this mixing, we analyse the evolution of the horizontally averaged dye front produced by adding a constant flux of dye to a steady plume for times t>0. We show that the centre of mass of the horizontally averaged dye front has an along-plume speed ${\approx}1.04f^{1/3}$. This is consistent with the predictions of a time-averaged model for the evolution of the horizontally averaged mass, momentum and buoyancy flux in the plume. The new data also show that the longitudinal spreading of the horizontally averaged dye front can be described in terms of a dispersivity ${\approx}\,0.02f^{1/3}z$, where $z$ is the vertical distance below the source. This model of longitudinal mixing enables calculation of the residence time distribution of material in the plume, which may be key to modelling the products of a reaction in which the reaction time is comparable to the travel time in the plume.This is the accepted manuscript. The final version is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9740664&fulltextType=RA&fileId=S0022112015002608

High-frequency cyclicity in the Mediterranean Messinian evaporites: evidence for solar-lunar climate forcing

The deposition of varved sedimentary sequences is usually controlled by climate conditions. The study of two Late Miocene evaporite successions (one halite and the other gypsum) consisting of annual varves has been carried out to reconstruct the paleoclimatic and paleoenvironmental conditions existing during the acme of the Messinian salinity crisis, ~ 6 Ma, when thick evaporite deposits accumulated on the floor of the Mediterranean basin. Spectral analyses of these varved evaporitic successions reveal significant periodicity peaks at around 3-5, 9, 11-13, 20-27 and 50-100 yr. A comparison with modern precipitation data in the western Mediterranean shows that during the acme of the Messinian salinity crisis the climate was not in a permanent evaporitic stage, but in a dynamic situation where evaporite deposition was controlled by quasi-periodic climate oscillations with similarity to modern analogs including Quasi-Biennial Oscillation, El Ni\~no Southern Oscillation, and decadal to secular lunar- and solar-induced cycles. Particularly we found a significant quasi-decadal oscillation with a prominent 9-year peak that is commonly found also in modern temperature records and is present in the contemporary Atlantic Multidecadal Oscillation (AMO) index and Pacific Decadal Oscillation (PDO) index. These cyclicities are common to both ancient and modern climate records because they can be associated with solar and solar-lunar tidal cycles.Comment: 13 pages, 10 figures, 1 Tabl

Modulation of Geraniol Metabolism During Alcohol Fermentation

n/

Some geological implications of the flow of clay-water mixtures

This thesis investigates three problems in the general area of environmental fluid mechanics. The first two problems are related to liquid or gas flow through clay-water suspensions, with relevance for the underground storage of radioactive waste and also for understanding the mechanism of eruption in mud volcanoes. The third problem centres on the different problem of mixing in a turbulent buoyant plume. First, the injection of gas and water from a central source into a two-dimensional layer of clay confined between two circular horizontal plates is investigated. This provides a model of the potential pressurisation and failure of the seal rock around a radioactive waste repository as may arise if gas is continuously generated in the repository. As the gas injection pressure is gradually increased the cell walls deform and the clay moves radially outwards. However, at a critical radius, the liquid-clay interface becomes unstable and a series of channels propagate through the clay. When one of the channels reaches the edge of the domain the gas escapes and the pressure is released. As a result, the domain relaxes by elastic deformation and the clay seals the channel. In this way, continuous fluid injection leads to episodic release of gas from the cell. The second problem concerns the flow of mud along a vertical conduit driven by the combined effect of reservoir pressure and buoyancy associated with the gas injected at the base of the conduit. This represents an analogue model of the eruption of a mud volcano, in which mud rises from a deep reservoir to the surface. I find that the pressure associated with the reservoir and any buoyancy force produced by the migration of gas from deep in the reservoir to the surface leads to a continuous eruption if the net pressure is greater than the yield stress of the clay. If the reservoir pressure falls during such an event, the eruption will eventually stop, once the pressure reaches a dynamic yield stress condition. Only later, if the reservoir pressure increases to the static yield stress of the clay will the eruption start again, and this can lead to a series of eruption cycles which depend on the non-Newtonian rheology of the clay. In contrast, if this pressure is smaller than the yield stress of the clay, a series of episodic gas burst events can occur until the conduit is cleared of mud. The third problem relates to the mixing in a turbulent buoyant plume. Through a series of new experiments and some complementary theoretical modelling I show that the mixing in a turbulent plume is strongly affected by the eddies and leads to significant longitudinal dispersion in the flow. The implications of the modelling for determining the residence time distribution of the fluid in the plume is discussed

Effects on mobility training and de-adaptations in subjects with Spinal Cord Injury due to a Wearable Robot: A preliminary report

open7noopenSale, Patrizio; Russo, Emanuele Francesco; Russo, Michele; Masiero, Stefano; Piccione, Francesco; Calabrò, Rocco Salvatore; Filoni, SerenaSale, Patrizio; Russo, Emanuele Francesco; Russo, Michele; Masiero, Stefano; Piccione, Francesco; Calabrò, Rocco Salvatore; Filoni, Seren

Effects of Waste Cooking Oil Biodiesel Use on Engine Fuel Consumption and Emissions: a Study on the Impact on Oxidation Catalyst and Particulate Filter

Abstract The wide use of biodiesel has been driven by its reduction potential on greenhouse emissions from diesel engines without significant technological modifications. In this study a diesel engine for non-road applications has been fuelled with Waste Cooking Oil biodiesel blended with commercial fossil fuel at 6% and 30% v/v. In line with literature trends, experimental results indicate a significant reduction of PM emissions and only a slight increase in NOx emissions. This study has been focused on diesel emissions and in particular on the analysis of PM/NO2 ratio in presence of the Diesel Oxidation Catalyst (DOC). In fact, although the NO2/NOx ratio on raw exhaust is almost unaffected, the use of biodiesel shows a slight reduction of the NO-NO2 light-off temperature. This reduction can ensure more favorable operating conditions for the Diesel Particulate Filter (DPF), and has a positive effect on fuel consumption reduction. In order to deeply analyze these issues, a numerical model of an Aftertreatment system (AS) representing the a DOC and a DPF has been developed and validated with experimental data

Data Rate vs. Maximum Reach in a Data Center Interconnect Scenario Exploiting Wideband InP Mach-Zehnder Modulators

A new Mach-Zehnder DP-IQ ultra-wideband indium phosphide modulator with integrated optical semiconductor amplifiers has been characterized for time domain simulations to investigate data rate versus maximum range in a DCI scenario

Involvement of recreational anglers in the eradication of alien brook trout from high altitude lakes

Stocking programmes for recreational angling are primarily responsible for the spread and ecological impact of introduced sh in high-altitude, originally shless lakes. In 2013, the Gran Paradiso National Park started an eradication campaign of brook trout by intensive gill-netting. Local anglers were invited to attend two angling sessions to start the eradication before gill-netting in an experimental lake, as part of an education action devoted to these critical stakeholders. The angling sessions turned out to be a valuable help for the eradication campaign and the aim of this study is to report on the outcomes of these angling sessions. Angling techniques were highly size-selective, removing a substantial part of the adult population and of the sh biomass, but their contribution to the eradication of small sh (<15cm) was irrelevant. Therefore, angling cannot completely eradicate age-structured populations. However, there is scope to use angling sessions as a support for eradication campaigns and as an emergency measure for recent sh introduc- tions. Similar actions should be considered whenever a sh eradication programme is planned. These ndings, however, do not imply a general endorsement for angling within protected areas