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Search Results: 1 - 10 of 223668 matches for " R. Canestrari "
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Analysis of microroughness evolution in X-ray astronomical multilayer mirrors by surface topography with the MPES program and by X-ray scattering
R. Canestrari,D. Spiga,G. Pareschi
Physics , 2015, DOI: 10.1117/12.671861
Abstract: Future hard X-ray telescopes (e.g. SIMBOL-X and Constellation-X) will make use of hard X-ray optics with multilayer coatings, with angular resolutions comparable to the achieved ones in the soft X-rays. One of the crucial points in X-ray optics, indeed, is multilayer interfacial microroughness that causes effective area reduction and X-Ray Scattering (XRS). The latter, in particular, is responsible for image quality degradation. Interfacial smoothness deterioration in multilayer deposition processes is commonly observed as a result of substrate profile replication and intrinsic random deposition noise. For this reason, roughness growth should be carefully investigated by surface topographic analysis, X-ray reflectivity and XRS measurements. It is convenient to express the roughness evolution in terms of interface Power Spectral Densities (PSD), that are directly related to XRS and, in turn, in affecting the optic HEW (Half Energy Width). In order to interpret roughness amplification and to help us to predict the imaging performance of hard X-ray optics, we have implemented a well known kinetic continuum equation model in a IDL language program (MPES, Multilayer PSDs Evolution Simulator), allowing us the determination of characteristic growth parameters in multilayer coatings. In this paper we present some results from analysis we performed on several samples coated with hard X-ray multilayers (W/Si, Pt/C, Mo/Si) using different deposition techniques. We show also the XRS predictions resulting from the obtained modelizations, in comparison to the experimental XRS measurements performed at the energy of 8.05 keV.
X-ray scattering of periodic and graded multilayers: comparison of experiments to simulations from surface microroughness characterization
B. Salmaso,D. Spiga,R. Canestrari,L. Raimondi
Physics , 2013, DOI: 10.1016/j.nima.2012.10.104
Abstract: To enhance the reflectivity of X-ray mirrors beyond the critical angle, multilayer coatings are required. Interface imperfections in the multilayer growth process are known to cause non-specular scattering and degrade the mirror optical performance; therefore, it is important to predict the amount of X-ray scattering from the rough topography of the outer surface of the coating, which can be directly measured, e.g., with an Atomic Force Microscope (AFM). This kind of characterization, combined with X-ray reflectivity measurements to assess the deep multilayer stack structure, can be used to model the layer roughening during the growth process via a well-known roughness evolution model. In this work, X-ray scattering measurements are performed and compared with simulations obtained from the modeled interfacial Power Spectral Densities (PSDs) and the modeled Crossed Spectral Densities for all the couples of interfaces. We already used this approach in a previous work for periodic multilayers; we now show how this method can be extended to graded multilayers. The upgraded code is validated for both periodic and graded multilayers, with a good accord between experimental data and model findings. Doing this, different kind of defects observed in AFM scans are included in the PSD analysis. The subsequent data-model comparison enables us to recognize them as surface contamination or interfacial defects that contribute to the X-ray scattering of the multilayer.
La Estructura del Dolo Eventual y las Nuevas Fenomenologías de Riesgo
Canestrari,Stefano;
Ius et Praxis , 2004, DOI: 10.4067/S0718-00122004000200003
Abstract: the article discusses the structure of dolus eventualis (recklessness), considering its contemporary phenomenology, and the contributions of judicial decisions and legal scholarship in germany and italy. especial consideration is given to the cases of sexually transmitted diseases and the refusal of blood transfusions to children by their jehova's witnesses parents. it is argued that the dominant doctrine of consent or acceptance does nor adequately resolve the analyzed phenomena, and a proposal is advanced towards a legal definition of the concept of recklessness.
La Estructura del Dolo Eventual y las Nuevas Fenomenologías de Riesgo
Stefano Canestrari
Ius et Praxis (En línea) , 2004,
Abstract: El texto aborda la discusión acerca de la estructura del dolo eventual, a partir de su fenomenología contemporánea, y el tratamiento que la jurisprudencia y doctrina alemana e italiana le han dado, particularmente en relación a supuestos relacionados con la transmisión de enfermedades de carácter sexual y de negativa de transfusión de sangre a menores por padres Testigos de Jehová. Se afirma que la doctrina dominante del consentimiento o aceptación no resuelve adecuadamente la fenomenología analizada y se plantea superar las dificultades que ello acarrea mediante la regulación legal del concepto de dolo eventual que se propone como conclusión The article discusses the structure of dolus eventualis (recklessness), considering its contemporary phenomenology, and the contributions of judicial decisions and legal scholarship in Germany and Italy. Especial consideration is given to the cases of sexually transmitted diseases and the refusal of blood transfusions to children by their Jehova's Witnesses parents. It is argued that the dominant doctrine of consent or acceptance does nor adequately resolve the analyzed phenomena, and a proposal is advanced towards a legal definition of the concept of recklessness.
Characterization of multilayer stack parameters from X-ray reflectivity data using the PPM program: measurements and comparison with TEM results
D. Spiga,A. Mirone,G. Pareschi,R. Canestrari,V. Cotroneo,C. Ferrari,C. Ferrero,L. Lazzarini,D. Vernani
Physics , 2015, DOI: 10.1117/12.672895
Abstract: Future hard (10 -100 keV) X-ray telescopes (SIMBOL-X, Con-X, HEXIT-SAT, XEUS) will implement focusing optics with multilayer coatings: in view of the production of these optics we are exploring several deposition techniques for the reflective coatings. In order to evaluate the achievable optical performance X-Ray Reflectivity (XRR) measurements are performed, which are powerful tools for the in-depth characterization of multilayer properties (roughness, thickness and density distribution). An exact extraction of the stack parameters is however difficult because the XRR scans depend on them in a complex way. The PPM code, developed at ERSF in the past years, is able to derive the layer-by-layer properties of multilayer structures from semi-automatic XRR scan fittings by means of a global minimization procedure in the parameters space. In this work we will present the PPM modeling of some multilayer stacks (Pt/C and Ni/C) deposited by simple e-beam evaporation. Moreover, in order to verify the predictions of PPM, the obtained results are compared with TEM profiles taken on the same set of samples. As we will show, PPM results are in good agreement with the TEM findings. In addition, we show that the accurate fitting returns a physically correct evaluation of the variation of layers thickness through the stack, whereas the thickness trend derived from TEM profiles can be altered by the superposition of roughness profiles in the sample image.
The INAF ASTRI Project in the framework of CTA
N. La Palombara,P. Caraveo,M. Fiorini,L. Stringhetti,R. Canestrari,R. Millul,G. Pareschi,O. Catalano,M. C. Maccarone,S. Vercellone,E. Giro,G. Tosti
Physics , 2014,
Abstract: The ASTRI project aims to develop, in the framework of the Cherenkov Telescope Array, an end-to-end prototype of the small-size telescope, devoted to the investigation of the energy range ~ 1-100 TeV. The proposed design is characterized by two challenging but innovative technological solutions which will be adopted for the first time on a Cherenkov telescope: a dual-mirror Schwarzschild-Couder configuration and a modular, light and compact camera based on Silicon photo-multipliers. Here we describe the prototype design, the expected performance and the possibility to realize a mini array composed by a few such telescopes, which shall be placed at the final CTA Southern Site.
The ASTRI Project: prototype status and future plans for a Cherenkov dual-mirror small-telescope array
S. Vercellone,O. Catalano,M. C. Maccarone,F. Di Pierro,P. Vallania,G. Bonnoli,R. Canestrari,G. Pareschi,P. Caraveo,N. La Palombara,M. Fiorini,L. Stringhetti,E. Giro,G. Tosti,for the ASTRI Collaboration
Physics , 2013,
Abstract: ASTRI ("Astrofisica con Specchi a Tecnologia Replicante Italiana") is a flagship project of the Italian Ministry of Education, University and Research. Within this framework, INAF is currently developing a wide field of view (9.6 degrees in diameter) end-to-end prototype of the CTA small-size telescope (SST), devoted to the investigation of the energy range from a fraction of TeV up to tens of TeVs, and scheduled to start data acquisition in 2014. For the first time, a dual-mirror Schwarzschild-Couder optical design will be adopted on a Cherenkov telescope, in order to obtain a compact optical configuration. A second challenging, but innovative technical solution consists of a modular focal surface camera based on Silicon photo-multipliers with a logical pixel size of 6.2mm x 6.2mm. Here we describe the current status of the project, the expected performance, and its possible evolution in terms of an SST mini-array. This CTA-SST precursor, composed of a few SSTs and developed in collaboration with CTA international partners, could not only peruse the technological solutions adopted by ASTRI, but also address a few scientific test cases that are discussed in detail.
The ASTRI Mini-Array Software System
G. Tosti,J. Schwarz,L. A. Antonelli,M. Trifoglio,G. Leto,F. Gianotti,R. Canestrari,O. Catalano,M. Fiorini,E. Giro,N. La Palombra,M. C. Maccarone,G. Pareschi,L. Stringhetti,S. Vercellone
Physics , 2013, DOI: 10.1117/12.2055067
Abstract: ASTRI ("Astrofisica con Specchi a Tecnologia Replicante Italiana") is a Flagship Project financed by the Italian Ministry of Education, University and Research, and led by INAF, the Italian National Institute of Astrophysics. Main goals of the ASTRI project are the realization of an end-to-end prototype of a Small Size Telescope (SST) for the Cherenkov Telescope Array (CTA) in a dual-mirror configuration (SST-2M) and, subsequently, of a mini-array composed of a few SST-2M telescopes to be placed at the final CTA Southern Site. Here we present the main features of the Mini-Array Software System (MASS) that has a central role in the success of the ASTRI Project and will also serve as a prototype for the CTA software system. The MASS will provide a set of tools to prepare an observing proposal, to perform the observations specified therein (monitoring and controlling all the hardware components of each telescope), to analyze the acquired data online and to store/retrieve all the data products to/from the archive.}
Analysis of a polymorphism within a TATA box of horse myostatin gene promoter in different breeds
S. Dall’Olio,A. Falaschini,M. Tassinari,G. Canestrari
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2007.1s.109
Abstract:
Grains colonised by moulds: fungal identification and headspace analysis of produced volatile metabolites
Laura Rizzi,Roberta Galuppi,Marco Simioli,Giorgia Canestrari
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2009.s2.334
Abstract: The aim of this work was to verify if the headspace analysis of fungal volatile compounds produced by some species of Fusarium can be used as a marker of mould presence on maize. Eight samples of maize (four yellow maize from North Italy and four white maize from Hungary), naturally contaminated by Fusarium and positive for the presence of fumonisins, were analyzed to detect moisture content, Aw, volatile metabolites and an enumeration of viable moulds was performed by means of a colony count technique. Headspace samples were analysed using a gas-chromatograph equipped with a capillary column TR-WAX to detect volatile metabolites of moulds. Furthermore macro and microscopic examination of the colonies was performed in order to distinguish, according to their morphology, the genera of the prevalent present moulds. Prevalent mould of eight samples was Fusarium, but other fungi, like Aspergillus, Penicillum and Mucoraceae, were observed. The metabolites produced by F.graminearum and F. moniliforme were Isobutyl-acetate, 3-Methyl-1-butanol and, only at 8 days, 3-Octanone. The incubation time can affect off flavour production in consequence of the presence of other moulds. Further studies on maize samples under different conditions are needed in order to establish the presence of moulds using the count technique and through the identification of volatile compounds.
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