Conditional sign flip via teleportation

We present a model to realize a probabilistic conditional sign flip gate using only linear optics. The gate operates in the space of number state qubits and is obtained by a nonconventional use of the teleportation protocol. Both a destructive and a nondestructive version of the gate are presented. In the former case an Hadamard gate on the control qubit is combined with a projective teleportation scheme mixing control and target. The success probability is 1/2. In the latter case we need a quantum encoder realized via the interaction of the control qubit with an ancillary state composed of two maximally entangled photons. The success probability is 1/4

Tell it to the hand: Attentional modulation in the identification of misoriented chiral objects

Research in the field of cognitive neuroscience and neuropsychology on spatial cognition and mental imagery has increased considerably over the last few decades. While at the beginning of the XX century studying imagery was considered an object of derision \u2013 a \u2015sheer bunk\u2016 (Watson, 1928) \u2013 at the present, imagery researchers have successfully developed models and improved behavioral and neurophysiological measures (e.g., Kosslyn et al., 2006). Mental rotation constituted a major advance in terms of behavioral measures sensitive to imaginative operations executed on visual representations (i.e., Shepard & Cooper, 1982). The linearity of modulation between response times and angular disparity of the images allowed a quantitative estimate of imagery processes. The experiments described in the present thesis were motivated by the intent to continue and extend the understanding of such fascinating mental phenomena. The evolution of the present work took initial steps from the adoption of a behavioral paradigm, the hand laterality judgment task, as privileged tool for studying motor imagery in healthy individuals and brain-damaged patients. The similarity with mental rotation tasks and the implicit nature of the task made it the best candidate to test hypotheses regarding the mental simulation of body movements. In this task, response times are linearly affected by the angular departures the hand pictures are shown in, as for mental rotation, and their distributions are asymmetric between left and right hands. Drawing from these task features a widely held view posits that laterality judgment of rotated hand pictures requires participants to imagine hand-arm movements, although they receive no instruction to do so (e.g., Parsons, 1987a; Parsons, 1994). In Chapter 1, I provided a review of the relevant literature on visual and motor imagery. Particular aspects of the mental rotation literature are also explored. In Chapter 2, I examined the hand laterality task and the vast literature of studies that employed this task as means to test motor imagery processes. An alternative view to the motor imagery account is also discussed (i.e., the disembodied account). In Chapter 3, I exploited the hand laterality task, and a visual laterality task (Tomasino et al., 2010) to test motor and visual imagery abilities in a group of healthy aged individuals. In Chapter 4, I described an alternative view that has been proposed by others to explain the pattern of RTs in the hand laterality task: The multisensory integration account (Grafton & Viswanathan, 2014). In this view, hand laterality is recognized by pairing information between the seen hand's visual features and the observer's felt own hand. In Chapter 5, I tested and found evidence for a new interpretation of the particular configuration of response times in the hand laterality task. I demonstrated a spatial compatibility effect for rotated pictures of hands given by the interaction between the direction of stimulus rotation (clockwise vs. counterclockwise) and the laterality of the motor response. These effects changed by following temporal dynamics that were attributed to shifts of spatial attention. In the same chapter, I conducted other psychophysics experiments that confirmed the role of spatial attention and that ruled out the view of multisensory integration as the key aspect in determining the asymmetries of the response times' distribution. In Chapter 6, I conducted a study with patients suffering from Unilateral Neglect in which they performed the hand laterality task and a visual laterality task. The findings indicated that patients failed to integrate visual information with spatially incompatible responses irrespective of the type of task, and depending on egocentric stimulus-response spatial codes. A general discussion is presented in Chapter 7

Water confined in nanopores: spontaneous formation of microcavities

Molecular Dynamics simulations of water confined in nanometer sized, hydrophobic channels show that water forms localized cavities for pore diameter ~ 2.0 nm. The cavities present non-spherical shape and lay preferentially adjacent to the confining wall inducing a peculiar form to the liquid exposed surface. The regime of localized cavitation appears to be correlated with the formation of a vapor layer, as predicted by the Lum-Chandler-Weeks theory, implying partial filling of the pore

Atmospheric monitoring in the mm and sub-mm bands for cosmological observations: CASPER2

Cosmological observations from ground at millimetre and sub-millimetre wavelengths are affected by atmospheric absorption and consequent emission. The low and high frequency (sky noise) fluctuations of atmospheric performance imply careful observational strategies and/or instrument technical solutions. Measurements of atmospheric emission spectra are necessary for accurate calibration procedures as well as for site testing statistics. CASPER2, an instrument to explore the 90-450 GHz (3-15 1/cm) spectral region, was developed and verified its operation in the Alps. A Martin-Puplett Interferometer (MPI) operates comparing sky radiation, coming from a field of view (fov) of 28 arcminutes (FWHM) collected by a 62-cm in diameter Pressman-Camichel telescope, with a reference source. The two output ports of the interferometer are detected by two bolometers cooled down to 300 mK inside a wet cryostat. Three different and complementary interferometric techniques can be performed with CASPER2: Amplitude Modulation (AM), Fast-Scan (FS) and Phase Modulation (PM). An altazimuthal mount allows the sky pointing, possibly co-alligned to the optical axis of the 2.6-m in diameter telescope of MITO (Millimetre and Infrared Testagrigia Observatory, Italy). Optimal timescale to average acquired spectra is inferred by Allan variance analysis at 5 fiducial frequencies. We present the motivation for and design of the atmospheric spectrometer CASPER2. The adopted procedure to calibrate the instrument and preliminary performance of the instrument are described. Instrument capabilities were checked during the summer observational campaign at MITO in July 2010 by measuring atmospheric emission spectra with the three different procedures.Comment: 11 pages, 9 figures, 2 tables, Accepted for publication in MNRA

Chirped seeded free-electron lasers: self-standing light sources for two-colour pump-probe experiments

We demonstrate the possibility to run a single-pass free-electron laser in a new dynamical regime, which can be exploited to perform two-colour pump-probe experiments in the VUV/X-ray domain, using the free-electron laser emission both as a pump and as a probe. The studied regime is induced by triggering the free-electron laser process with a powerful laser pulse, carrying a significant and adjustable frequency chirp. As a result, the emitted light is eventually split in two sub-pulses, whose spectral and temporal separations can be independently controlled. We provide a theoretical description of this phenomenon, which is found in good agreement with experiments performed on the FERMI@Elettra free-electron laser

Geoprocessing Web Services

Since 2003, Critech has performed research on web based geoprocessing. This was before OGC started work on the Web Processing Service standards. While continuously evaluating the benefits and drawbacks of existing (open-source and commercial) GIS software packages, the operational benefits of an ESRI site license drove the development in this area. Early work focused on scripting technologies. In 2007, Critech exploited the Application Program Interfaces (APIs) of ESRI software, in particular ESRI SDE. With the (stable) release of ESRI ArcGIS Server, web geoprocessing becomes an integral part of the software. This new technology will be used by Critech in 2008. This document reports on the status of the work.JRC.G.2-Support to external securit

Humanitarian Impact of Tropical Cyclones

JRC¿s research on tropical cyclones of 2007 builds the foundations for an innovative cyclone alert model. In contrast with the work of 2006 (focusing on wind speed modelling), 2007 focused on integrating data provided by other organisations into a single consequence analysis model. A collaboration with the Pacific Disaster Center allowed JRC to access structured data on tropical cyclone track information. This new source of information, available since August 2007, enables us to implement more advanced impact models which provide improved information for humanitarian emergency managers. As a result, since October 2007 GDACS maps feature tropical cyclone wind buffers overlaid on global real-time cloud images. While a lot of modelling work has been completed and geoprocessing systems were put in place to exploit this new source of data, the resulting products have not been integrated fully in GDACS.JRC.G.2-Support to external securit

Predicting and Optimizing Microswimmer Performance from the Hydrodynamics of Its Components: The Relevance of Interactions

Interest in the design of bioinspired robotic microswimmers is growing rapidly, motivated by the spectacular capabilities of their unicellular biological templates. Predicting the swimming speed and efficiency of such devices in a reliable way is essential for their rational design, and to optimize their performance. The hydrodynamic simulations needed for this purpose are demanding and simplified models that neglect nonlocal hydrodynamic interactions (e.g., resistive force theory for slender, filament-like objects that are the typical propulsive apparatus for unicellular swimmers) are commonly used. We show through a detailed case study of a model robotic system consisting of a spherical head powered by a rotating helical flagellum that (a) the errors one makes in the prediction of swimming speed and efficiency by neglecting hydrodynamic interactions are never quite acceptable and (b) there are simple ways to correct the predictions of the simplified theories to make them more accurate. We also formulate optimal design problems for the length of the helical flagellum giving maximal energetic efficiency, maximal distance traveled per motor turn, or maximal distance traveled per unit of work expended, and exhibit optimal solutions

Towards CFD guidelines for planing hull simulations based on the naples systematic series

Due to their higher motion amplitudes and instabilities, numerical simulations of planing hulls using Computational Fluid Dynamics (CFD) codes are more difficult than that of displacement ships. Indeed, for an accurate evaluation of the hydrodynamic performances of planing craft, the high-fidelity estimation of the pressure field around the hull is crucial. For this reason, validations and comparisons with experimental data are still important to identify the guidelines for both simulation settings and mesh generation. In this paper, two commercial packages will be compared focusing on a resistance case for the parent hull model (C1 hull) from the Naples Systematic Series (NSS) at four Froude numbers (Fr). The NSS is a new systematic series of hard chine hulls intensively tested in planing and semiplaning speed range, De Luca et al. [1]. It has been chosen for the hull form: it is characterized by a warped bottom and a sectional area curve significantly different from the prismatic hulls. These differences amplify the difficulties in finding out the exact pressure distribution on the bottom and, consequently, make the evaluation more stringent. The Unsteady Reynolds-Averaged Navier-Stokes flow solvers results are validated using these benchmark experimental data. Also, grid independence, iteration, and time-step convergence analysis for response variables (resistance coefficients, wetted surfaces, and dynamic trim angles) follow the recommendations published in the verification and validation (V&V) study from De Luca et al. [2]. Hence, the two software are more compared on different features such as the mesh deformation, the overset method, and the correction of numerical ventilation classically observed below the hull. The results show that both software can provide consistent values and that new guidelines are now identified to improve the reliability of the simulations

Mesoscopic continuous and discrete channels for quantum information transfer

We study the possibility of realizing perfect quantum state transfer in mesoscopic devices. We discuss the case of the Fano-Anderson model extended to two impurities. For a channel with an infinite number of degrees of freedom, we obtain coherent behavior in the case of strong coupling or in weak coupling off-resonance. For a finite number of degrees of freedom, coherent behavior is associated to weak coupling and resonance conditions