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High-speed flow of interacting organic polaritons

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Light(Science & Applications) 2016年第1期5卷 235-240页

作者： Giovanni Lerario Dario Ballarini Antonio Fieramosca Alessandro Cannavale Armando Genco Federica Mangione Salvatore Gambino Lorenzo Dominici Milena De Giorgi Giuseppe Gigli Daniele Sanvitto cnr nanotec-Istituto di nanotecnologia Via Monteroni73100 LecceItaly Dipartimento di matematica e fisica‘Ennio De Giorgi’ Universitàdel Salento73100 LecceItaly

The strong coupling of an excitonic transition with an electromagnetic mode results in composite quasi-particles called exciton polaritons,which have been shown to combine the best properties of their individual components in semiconductor ***,the physics and applications of polariton flows in organic materials and at room temperature are still unexplored because of the poor photon confinement in such ***,we demonstrate that polaritons formed by the hybridization of organic excitons with a Bloch surface wave are able to propagate for hundreds of microns showing remarkable third-order nonlinear interactions upon high injection *** findings pave the way for the study of organic nonlinear light–matter fluxes and for a technologically promising route of the realization of dissipation-less on-chip polariton devices operating at room temperature.

关键词： optical nonlinearity organic materials polaritons surface waves 2D optics

Speckle spatial correlations aiding optical transmission matrix retrieval:the smoothed Gerchberg–Saxton single-iteration algorithm

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Photonics Research 2022年第10期10卷 2349-2358页

作者： DANIELE ANCORA LORENZO DOMINICI ANTONIO GIANFRATE PAOLO CAZZATO MILENA DE GIORGI DARIO BALLARINI DANIELE SANVITTO LUCA LEUZZI Department of Physics Universitàdi Roma la SapienzaPiazzale Aldo Moro 5I-00185 RomeItaly Institute of nanotechnology Consiglio Nazionale delle Ricerche(CNR-NANOTEC)Via MonteroniI-73100 LecceItaly Institute of nanotechnology Soft and Living Matter LaboratoryConsiglio Nazionale delle Ricerche(CNR-NANOTEC)Piazzale Aldo Moro 5I-00185 RomeItaly

The estimation of the transmission matrix of a disordered medium is a challenging problem in disordered ***,its reconstruction relies on a complex inversion that aims at connecting a fully controlled input to the deterministic interference of the light field scrambled by the *** the moment,iterative phase retrieval protocols provide the fastest reconstructing frameworks,converging in a few tens of *** the knowledge of speckle correlations,we construct a new phase retrieval algorithm that reduces the computational cost to a single *** being faster,our method is practical because it accepts fewer measurements than state-of-the-art *** to reducing computation time by one order of magnitude,our result can be a step forward toward real-time optical imaging that exploits disordered devices.

关键词： optical matrix algorithm

Simplified hydrodynamic models for the analysis of marine propellers in a wake-field

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Journal of Hydrodynamics 2013年第6期25卷 954-965页

作者： DURANTE D. DUBBIOSO G. TESTA C. cnr-INSEAN The Italian Ship Model Basin

This paper presents a comparison among different hydrodynamic models for the analysis of the unsteady loads delivered by a marine propeller working in an axial, non-uniform inflow. Specifically, for a propeller subjected to a wake-field dominated by local high-frequency changes in space, the unsteady hydroloads predicted by the Nakatake formulation are compared with those given by the Theodorsen and Sears theories, respectively. Drawbacks and potentialities of these approaches are highlighted to assess a computationally efficient hydrodynamic solver for the analysis of operating conditions where propeller blades are significantly perturbed by a multi-harmonic onset-flow. Guidelines coming from this investigation may drive the choice of a fast and reliable unsteady propeller modeling that represents a good trade-off between accuracy of simulation and cost of computation within implementation in Computational Fluid Dynamics （CFD） solvers. The hydrodynamic formulations herein proposed are validated through numerical comparisons with the （accurate but computationally expensive） propeller loads predicted by a fully 3-D panel-method Boundary Element Method （BEM） solver, suited for the analysis of propellers operating in a complex hydrodynamic environment.

关键词： actuator disk airfoil theories Boundary Element Method (BEM) hydrodynamics

Post-synthesis phase and shape evolution of CsPbBr3 colloidal nanocrystals: The role of ligands

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Nano Research 2019年第5期12卷 1155-1166页

作者： Elisabetta Fanizza Francesca Cascella Davide Altamura Cinzia Giannini Annamaria Panniello Leonardo Triggiani Francesca Panzarea Nicoletta Depalo Roberto Grisorio Gian Paolo Suranna Angela Agostiano M.Lucia Curri Marinella Striccoli Dipartimento di Chimica Università degli Studi di Bari "A.Moro"Via Orabona 470126 BariItaly cnr-Istituto per i Processi Chimico Fisici S.S.BariVia Orabona470126 BariItaly cnr-Istituto di Cristallografia Via Amendola122/O70126 BariItaly yDipartimento di Ingegneria Civile Ambientaledel TerritorioEdile e di Chimica(DICATECh)Politecnico di BariVia Orabona 470125Italy cnr-nanotec-Istituto di nanotecnologia Via Monteroni 73100 LecceItaly

The surface chemistry of colloidal cesium lead bromide (CsPbBr3) nanocrystals is decisive in determining the stability and the final morphology of this class of materials,characterized by ionic structure and a high defect tolerance ***,the high sensitivity of purified colloidal nanocubes of CsPbBr3 to diverse environmental condition (solvent dilution,ageing,ligands post synthetic treatment) in ambient atmosphere is investigated by means of a comprehensive morphological (electron microscopy),structural (θ/2θ X-ray diffraction (XRD) and grazing incidence wide angle scattering (GIWAXS)),and spectroscopic chemical (1H nuclear magnetic resonance (NMR),nuclear Overhauser effect spectroscopy (NOESY),absorption and emission spectroscopy) *** aging and solvent dilution contribute to modify the nanocrystal morphology,due to a modification of the ligand ***,we establish the ability of aliphatic carboxylic acids and aikyl amines ligands to induce,even in a post preparative process at room temperature,structural,morphological and spectroscopic *** post synthesis alkyl amine addition,in particular of oleyl amine and octyl amine,the highly green emitting CsPbBr3 nanocubes effectively tum into one-dimensional (1 D) thin tetragonal nanowires or lead halide deficient rhombohedral zero-dimensional (0D) Cs4PbBr6 structures with a complete loss of *** addition of an alkyl carboxylic acid,as oleic and nonanoic acid,produces the transformation of nanocubes into still emitting orthorombic two-dimensional (2D) *** acid/base equilibrium between the native and added ligands,the edsorbed/free ligands dynamic in solution and the ligand solubility in non-polar solvent contribute to render CsPbBr3 particularly sensitive to environmental and processing conditions and,therefore prone to undergo to structural,morphological and,hence spectroscopic,transformations.

关键词： lead halide perovskite nanocrystals surface chemistry ligands equilibria long term stability

Can leukocyte telomere shortening be a possible biomarker to track Huntington’s disease progression?

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Neural Regeneration Research 2019年第10期14卷 1709-1710页

作者： Elide Mantuano Martina Peconi Daniela Scarabino cnr Institute of Translational Pharmacology RomeItaly cnr Institute of Molecular Biology and Pathology Rome Italy

Huntington's disease (HD): HD is an autosomal dominant neurodegenerative disease, caused by a CAG trinucleotide repeat expansion in the first exon of the HTT gene encoding the huntingtin protein. The mutant protein contains an expanded polyglutamine sequence that confers a toxic gain-of-function and causes neurodegeneration. Moreover, several studies indicate that loss of the normal protein beneficial functions, contribute to the pathology (Schulte and Littleton 2011). Triplet expansion over 40 repeats are fully penetrant and invariably lead to manifest HD in the fourth or fifth decade of life.

关键词： Huntington's disease(HD) neurodegenerative disease fifth decade of life

Surface modification of polypropylene non-woven fibers with TiO_2 nanoparticles via layer-by-layer self assembly method:Preparation and photocatalytic activity

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Journal of Environmental Sciences 2015年第11期27卷 59-66页

作者： Suttipan Pavasupree Stephan T.Dubas Ratthapol Rangkupan Metallurgy and Materials Science Research Institute Chulalongkorn University Petroleum and Petrochemical College Chulalongkorn University Chulalongkorn University Nanotec-CU Center of Excellence on Food and Agriculture Chulalongkorn University

Polypropylene（PP） meltblown fibers were coated with titanium dioxide（Ti O2） nanoparticles using layer-by-layer（Lb L） deposition technique. The fibers were first modified with 3layers of poly（4-styrenesulfonic acid）（PSS） and poly（diallyl-dimethylammonium chloride）（PDADMAC） to improve the anchoring of the Ti O2 nanoparticle clusters. PDADMAC, which is positively charged, was then used as counter polyelectrolyte in tandem with anionic Ti O2 nanoparticles to construct Ti O2/PDADMAC bilayer in the Lb L fashion. The number of deposited Ti O2/PDADMAC layers was varied from 1 to 7 bilayer, and could be used to adjust Ti O2 loading. The Lb L technique showed higher Ti O2 loading efficiency than the impregnation approach. The modified fibers were tested for their photocatalytic activity against a model dye, Methylene Blue（MB）. Results showed that the Ti O2 modified fibers exhibited excellent photocatalytic activity efficiency similar to that of Ti O2 powder dispersed in solution. The deposition of Ti O23 bilayer on the PP substrate was sufficient to produce nanocomposite fibers that could bleach the MB solution in less than 4 *** O2-Lb L constructions also preserved Ti O2 adhesion on substrate surface after 1 cycle of photocatalytic test. Successive photocatalytic test showed decline in MB reduction rate with loss of Ti O2 particles from the substrate outer surface. However, even in the third cycle, the Ti O2 modified fibers are still moderately effective as it could remove more than 95% of MB after 8 hr of treatment.

关键词： Layer-by-layer Self assembly TiO2 Nanocomposite Photocatalytic activity

Comparison of PM_(10) concentrations and metal content in three different sites of the Venice Lagoon: An analysis of possible aerosol sources

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Journal of Environmental Sciences 2012年第11期24卷 1954-1965页

作者： Daniele Contini Franco Belosi Andrea Gambaro Daniela Cesari Angela Maria Stortini Maria Chiara Bove Institute of Atmospheric Sciences and Climate ISAC-CNRLecceItaly Institute of Atmospheric Sciences and Climate ISAC-CNRBolognaItaly Department of Environmental Sciences Informatics and StatisticsUniversity Ca'Foscari of VeniceVeneziaItaly Institute of Atmospheric Sciences and Climate ISAC-CNRLecceItaly. Institute for the Dynamics of Environmental Processes IDPA-CNRVeneziaItaly

The Venice Lagoon is exposed to atmospheric pollutants from industrial activities, thermoelectric power plants, petrochemical plants, incinerator, domestic heating, ship traffic, glass factories and vehicular emissions on the mainland. In 2005, construction began on the mobile dams （MOSE）, one dam for each channel connecting the lagoon to the Adriatic Sea as a barrier against high tide. These construction works could represent an additional source of pollutants. PM10 samples were taken on random days between 2007 and 2010 at three different sites： Punta Sabbioni, Chioggia and Malamocco, located near the respective dam construction worksites. Chemical analyses of V, Cr, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, Sb, T1 and Pb in PM10 samples were performed by Inductively coupled plasma- quadrupole mass spectrometry （ICP-QMS） and results were used to identify the main aerosol sources. The correlation of measured data with meteorology, and source apportionment, failed to highlight a contribution specifically associated to the emissions of the MOSE construction works. The comparison of the measurements at the three sites showed a substantial homogeneity of metal concentrations in the area. Source apportionment with principal component analysis （PCA） and positive matrix factorization （PMF） showed that a four principal factors model could describe the sources of metals in PM10. Three of them were assigned to specific sources in the area and one was characterised as a source of mixed origin （anthropogenic and crustal）. A specific anthropogenic source of PM10 rich in Ni and Cr, active at the Chioggia site, was also identified.

关键词： MOdulo Sperimentale Elettromeccanico metals Venice Lagoon PM10 principal component analysis positive matrixfactorization

The measure of friction angles for different types of granular material

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Journal of Mountain Science 2019年第4期16卷 769-777页

作者： DEGANUTTI Andrea Maria TECCA Pia Rosella GENEVOIS Rinaldo cnr-IRPI Department of Geosciences University of Padova

The aim of this research is to deepen the knowledge of the role of friction on the dynamics of granular media; in particular the friction angle is taken into consideration as the physical parameter that drives stability, motion and deposition of a set of grains of any nature and size. The idea behind this work is a question: is the friction angle really that fundamental and obvious physical parameter which rules stability and motion of granular media as it seems from most works which deal with particle dynamics? The experimental study tries to answer this question with a series of laboratory tests, in which different natural and artificial granular materials have been investigated in dry condition by means of a tilting flume. The characteristic friction angles, both in deposition(repose) and stability limit(critical) conditions, were measured and checked against size, shape, density and roughness of the considered granular material. The flume tests have been preferred to "classical" geotechnical apparatuses(e.g. shear box) since the flume experimental conditions appear closer to the natural ones of many situations of slope stability interest(e.g. a scree slope). The results reveal that characteristic friction angles depend on size and shape of grains while mixtures of granules of different size show some sorting mechanism with less clear behaviour.

关键词： Rheology Granular material Friction angle Deposition process Yielding process

Marine propellers performance and flow-field prediction by a free-wake panel method

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Journal of Hydrodynamics 2014年第5期26卷 780-795页

作者： GRECO Luca MUSCARI Roberto TESTA Claudio DI MASCIO Andrea cnr-INSEAN Italian Ship Model BasinRomeItaly cnr-IAC Istituto per le Applicazioni del Calcolo "M. Picone"RomeItaly

A Boundary Element Method （BEM） hydrodynamics combined with a flow-alignment technique to evaluate blades shed vorticity is presented and applied to a marine propeller in open water. Potentialities and drawbacks of this approach in capturing propeller performance, slipstream velocities, blade pressure distribution and pressure disturbance in the flow-field are highlighted by comparisons with available experiments and RANSE results. In particular, correlations between the shape of the convected vortex- sheet and the accuracy of BEM results are discussed throughout the paper. To this aim, the analysis of propeller thrust and torque is the starting point towards a detailed discussion on the capability of a 3-D free-wake BEM hydrodynamic approach to describe the local features of the flow-field behind the propeller disk, in view of applications to propulsive configurations where the shed wake plays a dominant role.

关键词： BEM hydrodynamics free-wake analysis BEM-RANSE comparison