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The Innovation 2024年第2期5卷 115-121页

作者： Jean-Luc Bloechle Julien Audiffren Thibaut Le Naour Andrea Alli Dylan simoni gabriel Wüthrich Jean-Pierre Bresciani Control and Perception Laboratory University of FribourgBd Perolles 901700 FribourgSwitzerland Motion-up Le PrismePlace Albert Einstein56000 VannesFrance FC Basel 1893 Birsstrasse 320A4002 BaselSwitzerland

Penalty kicks are increasingly decisive in major international football ***,over 30%of shootout kicks are *** outcome of the kick often relies on the ability of the penalty taker to exploit anticipatory movements of the goalkeeper to redirect the kick toward the open side of the ***,this ability is difficult to train using classical *** used an augmented reality simulator displaying an holographic goalkeeper to test and train penalty kick performance with 13 young elite *** learning algorithms were used to optimize the learning rate by maintaining an optimal level of training *** training sessions of 20 kicks reduced the redirection threshold by 120 ms,which constituted a 28%reduction with respect to the baseline ***,redirection threshold reduction was observed for all trained players,and all things being equal,it corresponded to an estimated 35%improvement of the success rate.

关键词： kick penalty learning

gate-controlled supercurrent effect in dry-etched Dayem bridges of non-centrosymmetric niobium rhenium

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Nano Research 2024年第7期17卷 6575-6581页

作者： Jennifer Koch Carla Cirillo Sebastiano Battisti Leon Ruf Zahra Makhdoumi Kakhaki Alessandro Paghi Armen gulian Serafim Teknowijoyo giorgio De simoni Francesco giazotto Carmine Attanasio Elke Scheer Angelo Di Bernardo Department of Physics University of KonstanzUniversitätsstraße 1078464 KonstanzGermany CNR-Spin c/o Universitàdegli Studi di Salernovia Giovanni Paolo II 13284084 Fisciano(SA)Italy NEST Istituto Nanoscienze-CNR and Scuola Normale SuperiorePiazza San Silvestro 1256127 PisaItaly Dipartimento di Fisica“E.R.Caianiello” Universitàdegli Studi di SalernoVia Giovanni Paolo II 13284084 Fisciano(SA)Italy Advanced Physics Laboratory Institute for Quantum StudiesChapman UniversityBurtonsvilleMD 20866USA

The application of a gate voltage to control the superconducting current flowing through a nanoscale superconducting constriction,named as gate-controlled supercurrent(gCS),has raised great interest for fundamental and technological *** gain a deeper understanding of this effect and develop superconducting technologies based on it,the material and physical parameters crucial for the gCS effect must be ***-down fabrication protocols should also be optimized to increase device scalability,although studies suggest that top-down fabricated devices are more resilient to show a ***,we investigate gated superconducting nanobridges made with a top-down fabrication process from thin films of the noncentrosymmetric superconductor niobium rhenium with varying ratios of the constituents(NbRe).Unlike other devices previously reported and made with a top-down approach,our NbRe devices systematically exhibit a gCS effect when they were fabricated from NbRe thin films with small grain size and etched in specific *** observations pave the way for the realization of top-down-made gCS devices with high *** results also imply that physical parameters like structural disorder and surface physical properties of the nanobridges,which can be in turn modified by the fabrication process,are crucial for a gCS observation,providing therefore also important insights into the physics underlying the gCS effect.

关键词： superconductivity non-centrosymmetric superconductors superconducting devices gated devices gate-controlled supercurrent top-down fabrication

An Experimental Investigation of the Dissipation Mechanisms in the Suction Side Boundary Layer of a Turbine Blade

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Journal of Thermal Science 2008年第4期17卷 289-297页

作者： Francesca Satta Daniele simoni Marina Ubaldi Pietro Zunino Dipartimento di Macchine Sistemi Energetici e Trasporti-Università di Genova

The present work is part of an extensive experimental activity carried out by the authors in recent years aimed at investigating the boundary layer transition phenomenon in turbine blades. The large scale of the cascade and the use of advanced LDV instrumentation and precision probe traversing mechanism resulted in high degree of spatial resolution and high accuracy of measurements. The main dissipation mechanism determining the profile losses in turbomachinery blades is the work of deformation of the mean motion within the boundary layer operated by both viscous and turbulent shear stresses. In the present paper, the local viscous and turbulent deformation works have been directly evaluated from the detailed measurements of boundary layer mean velocity and Reynolds shear stress. The results show the distributions and the relative importance of the viscous and turbulent contributions to the loss production, in relation with the boundary layer states occurring along the turbine profile.

关键词： Axial flow turbines Profile boundary layer Energy dissipation mechanism Boundary layer transition Laser Doppler measurements.

Experimental Investigation of Flow Instabilities in a Laminar Separation Bubble

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Journal of Thermal Science 2014年第3期23卷 203-214页

作者： simoni D. Ubaldi M. Zunino P. DIME-Università di genovaVia Montallegro 1 I-16145 Genova Italy DIME-Università di genova Via Montallegro 1 I-16145 Genova Italy

The present paper reports the results of a detailed experimental study aimed at investigating the dynamics of a laminar separation bubble, from the origin of separation up to the breakdown to turbulence of the large scale co- herent structures generated as a consequence of the Kelvin-Helmholtz instability process. Measurements have been performed along a fiat plate installed within a double contoured test section, designed to produce an adverse pressure gradient typical of Ultra-High-Lift turbine blade profiles, which induces the formation of a laminar separation bubble at low Reynolds number condition. Measurements have been carried out by means of comple- mentary techniques： hot-wire （HW） anemometry, Laser Doppler Velocirnetry （LDV） and Particle Image Veloci- metry （PIV）. The high accuracy 2-dimensional LDV results allow investigating reverse flow magnitude and both Reynolds normal and shear stress distributions along the separated flow region, while the high frequency response of the HW anemometer allows analyzing the amplification process of flow oscillations induced by instability mechanisms. PIV results complement the flow field analysis providing information on the generation and evolu- tion of the large scale coherent structures shed as a consequence of the separated shear layer roll-up, through in- stantaneous velocity vector maps. The simultaneous analysis of the data obtained by means of the different meas- uring techniques allows an in depth view of the instability mechanisms involved in the transition/reattachrnent processes of the separated shear layer.

关键词： Ultra-High-Lift turbine profiles separated flow transition mode streaks Kelvin-Helmholtz instabil- ity linear stability theory

Large Eddy Simulation of the By-pass Transition Process under Different Inlet Turbulence Conditions

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Journal of Thermal Science 2021年第6期30卷 2112-2121页

作者： BARSI Dario COSTA Carlo LENgANI Davide simoni Daniele UBALDI Marina DIME-University of genova Via Montallegro 11-16145 GenovaItaly

The transition process of the boundary layer developing over a flat plate with elevated inlet Free Stream Turbulence Intensity(FSTI)has been studied by means of Large Eddy Simulation(LES).To this purpose,four cases with different inflow disturbances have been tested varying the magnitude and the length scale of *** has been performed by using the finite-volume ANSYS Fluent *** computational domain,which was constituted by a rectangular domain with a zero thickness plate,was based on an ERCOFTAC test case in order to provide a validation with a well-known set of data by comparing the boundary layer integral parameters and mean and fluctuating streamwise velocity *** four cases were discussed within the paper by looking at classical statistical properties as well as advanced post-processing *** was shown that the decrease in the free stream turbulence level postpones the transition location,whereas the variation of the integral length scale has a very low influence on the distribution of the time-mean flow *** Orthogonal Decomposition(POD)has been applied to the instantaneous LES flow fields in order to provide a statistical representation of the structures responsible for transition and their response to free-stream turbulence intensity and length *** presence of vortical filaments parallel to the wall,typically referred as boundary layer streaks,is clearly identified;their characteristic dimensions and how they change as a function of FSTI properties were analyzed within the paper.

关键词： by-pass transition Large Eddy Simulation(LES) Proper Orthogonal Decomposition(POD) boundary layer streaks

Experimental Investigation of Separation and Transition Processes on a High-Lift Low-Pressure Turbine Profile Under Steady and Unsteady Inflow at Low Reynolds Number

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Journal of Thermal Science 2010年第1期19卷 26-33页

作者： Satta F simoni D Ubaldi M Zunino P Bertini F DIMSET-Università di genova Via Montallegro 1I-16145 GenovaItaly Avio R&D V.I Maggio99 I-10040 Rivalta(TO)-Italy

The effects induced by the presence of incoming wakes on the boundary layer developing over a high-lift low-pressure turbine profile have been investigated in a linear cascade at *** tested Reynolds number is 70000,typical of the cruise operating *** results of the investigations performed under steady and unsteady inflow conditions are *** unsteady investigations have been performed at the reduced frequency of f+=0.62,representative of the real engine operating *** aerodynamic loadings as well as boundary layer velocity profiles have been measured to survey the separation and transition *** analysis has been also performed to better understand the phenomena associated with the transition process under steady *** the unsteady case,a phase-locked ensemble averaging technique has been employed to reconstruct the time-resolved boundary layer velocity distributions from the hot-wire instantaneous signal *** ensemble-averaging technique allowed a detailed analysis of the effects induced by incoming wakes-boundary layer interaction in separation ***-resolved results are presented in terms of mean velocity and unresolved unsteadiness time-space plots.

关键词： boundary layer separation boundary layer transition wake-boundary layer interaction high-liftprofile low-pressure turbine

Experimental and Numerical Analysis of Cavity/Mean-Flow Interaction in Low Pressure Axial Flow Turbines

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Journal of Thermal Science 2021年第6期30卷 2178-2185页

作者： BARSI Dario COSTA Carlo LENgANI Davide simoni Daniele VENTURINO giulio ZUNINO Pietro DIME-Universita di genova Via Montallegro 11-16145 Genova

The increasing performance of modern aeroengines led the research towards the optimization of machine components not deeply analyzed in the *** this context,the mechanisms driving the interaction process between the secondary flows evolving at the hub of low-pressure turbines with the rotor-stator cavity systems have been poorly investigated in the *** this work,an experimental and numerical analysis of the interaction between the endwall near wall flow and the leakage flow of a real cavity system is *** experimental results were carried out in the annular low-pressure axial flow turbine of the University of *** blade loading and pressure distributions into the cavity,as well as the measured total pressure loss coefficient,have been used for a proper validation of CFD *** steady and unsteady calculations were carried out through the commercial solver ***,several numerical approaches have been tested into this work:RANS,Non Linear Harmonic(NLH),and *** most promising CFD techniques have been firstly identified by comparison with experimental results and then systematically employed to extend the analysis of secondary flow-cavity flow interaction to positions and quantities not available from the *** characterizing the mean flow-cavity flow interaction process will be shown to cover a great amount of the overall stage losses and should be properly accounted for the design of future optimized cavity configurations.

关键词： axial flow turbine cavity mean-flow interaction experimental analysis CFD

Free-stream Turbulence Effects on the Boundary Layer of a High-lift Low-Pressure-Turbine Blade

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Journal of Thermal Science 2016年第3期25卷 195-206页

作者： simoni D. Ubaldi M. Zunino p. Ampellio E. DIME-Universita di genova Via MontaUegro 11-16145 GenovaItaly gE AvioAero S.p.A. V.I Maggio99 1-10040 Rivalta(TO)-Italy

The suction side boundary layer evolution of a high-lift low-pressure turbine cascade has been experimentally in- vestigated at low and high free-stream turbulence intensity conditions. Measurements have been carded out in order to analyze the boundary layer transition and separation processes at a low Reynolds nttmber, under both steady and unsteady inflows. Static pressure distributions along the blade surfaces as well as total pressure distri- butions in a downstream tangential plane have been measured to evaluate the overall aerodynamic efficiency of the blade for the different conditions. Particle. Image Velocimetry has been adopted to analyze the time-mean and time-varying velocity fields. The flow field has been surveyed in two orthogonal planes （a blade-to-blade plane and a wall-parallel one）. These measurements allow the identification of the Kelvin-Helmholtz large scale cohe- rent structures shed as a consequence of the boundary layer laminar separation under steady inflow, as well as the investigation of the three-dimensional effects induced by the intermittent passage of low and high speed streaks. A close inspection of the time-mean velocity profiles as well as of the boundary layer integral parameters helps to characterize the suction side boundary layer state, thus justifying the influence of free-stream turbulence intensity on the blade aerodynamic losses measured under steady and unsteady inflows.

关键词： profile losses high-lift profiles free-stream turbulence streaks unsteady flows.

Specific contribution of mannose-binding lectin murine isoforms to brain ischemia/reperfusion injury

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Cellular & Molecular Immunology 2020年第3期17卷 218-226页

作者： Laura Neglia Marco Oggioni Domenico Mercurio Maria-grazia De simoni Stefano Fumagalli1 Istituto di Ricerche Farmacologiche Mario Negri IRCCS Department of NeuroscienceMilanItaly

Mannose-binding lectin(MBL),an initiator of the lectin pathway(LP)of complement activation,is detrimental in ischemic stroke,as shown in clinical studies and rodent *** humans have one functional MBL protein,rodents have two isoforms,MBL-A and MBL-C,whose functions relative to that of human MBL are *** permit the clinical translation of preclinical data,we aimed to define the specific contributions of MBL-A and MBL-C to brain *** subjected mice with double(MBL^(−/−))or single(MBL-A^(−/−)or MBL-C^(−/−))MBL isoform depletion to transient middle cerebral artery occlusion(tMCAo).MBL^(−/−) mice had fewer neurological deficits and smaller ischemic lesions than WT ***-A^(−/−) mice had smaller lesions than WT mice and exhibited no significant behavioral defects,whereas MBL-C^(−/−) mice did not differ from WT *** induction of Mbl1 and Mbl2(the MBL-A and MBL-C genes)expression 48 h after tMCAo was similar across *** time course of Mbl1 and Mbl2 expression in WT ischemic mice showed that Mbl1 activation occurred earlier(24 h)than Mbl2 activation(48 h).The plasma levels of MBL-A and MBL-C in MBL-C^(−/−) and MBL-A^(−/−) mice,respectively,were similar to those in WT mice both at baseline and at 48 h after *** 48 h,MBL-A^(−/−)ischemic mice showed higher MBL-C levels in the brain than WT *** and MBL-C^(−/−) ischemic mice had higher LP activity in plasma and,accordingly,higher levels of C3 deposition in the brain than MBL-A^(−/−) and MBL^(−/−) *** conclusion,mice with depletion of both MBL isoforms exhibited strong protection from ischemia/reperfusion ***-A was the main contributor to injury,likely owing to its earlier activation after ischemia and more efficient activation of the complement system than MBL-C.

关键词： injury depletion likely