Morphology of Calcite (CaCO3)Crystals Growing from Aqueous Solutions in the Presence of Li+ Ions. Surface Behavior of the (0001)Form.

Single micro-crystals of zabuyelite were observed on 0001 calcite surfaces, epitaxilly grown and oriented along the direction of calcite, the (001) faces of zabuyelite being by far the the best candidate to form the epitaxial interface

(100) and (111) Forms of NaCl-like Crystals Coexisting in Growth from Pure Aqueous Solution.

The Authors prove, by means of SEM, the co-existence of (100) and (111) forms in pure aqueous solution in well defined supersaturation range. The consequences of the "octopole hypothesis" is discussed. Finally, according to the calculation of the reconstructed (111) surfaces, the equilibrium shape of the crystals was determined

Trattamento delle superfici - Il plasma freddo migliora l'incollaggio

I plasmi sono mezzi chimicamente attivi. In relazione alle modalit\ue0 di attivazione e alla loro potenza di lavoro possono generare temperature molto alte o basse; nel primo caso si parla di plasma termico, nel secondo di plasma freddo. L\u2019ampio intervallo di temperatura consente una grande variet\ue0 di applicazioni. Il plasma termico, grazie alle elevatissime temperature generate, \ue8 ampiamente utilizzato in ambito metallurgico per il taglio e la saldatura dei metalli. Le applicazioni industriali della tecnologia del plasma freddo, pur essendo le pi\uf9 svariate, possono essere tutte ricondotte a operazioni di modifica superficiale: attivare, pulire, rivestire le superfici. Un trattamento in plasma freddo consente, infatti, di ricerca ottenere superficialmente dei composti chimici reattivi che non sono ottenibili con procedimenti chimici tradizionali. Un considerevole vantaggio consiste nel fatto di poter realizzare un trattamento che coinvolge solo gli strati superficiali di materiale, che lascia quindi inalterate le propriet\ue0 meccaniche generali, adottando tra l\u2019altro temperature di processo poco elevate che non danneggiano eventuali substrati degradabili. Proprio quest\u2019ultimo vantaggio offre una possibile soluzione ai problemi di bagnabilit\ue0 e, conseguentemente, di incollaggio di alcune tipologie di polimeri, tra cui per esempio il polietilene o il polipropilene, che presentano scarsissime propriet\ue0 di adesione ma un vasto campo di impiego. Queste le ragioni alla base di una ricerca finalizzata alla valutazione dell\u2019effetto di un trattamento in plasma freddo sulle caratteristiche di adesione del polietilene. L\u2019obiettivo \ue8 quello di individuare i parametri di macchina \u2013 potenza e tempo di esposizione \u2013 pi\uf9 idonei a garantire il miglior risultato in termini di resistenza a taglio di un giunto incollato

Temperature measurements in Xe + Cu at 30 MeV/nucleon: Size effects in the caloric curve

PHYSICAL REVIEW

Isogeometric solution of helmholtz equation with dirichlet boundary condition in regions with irregular boundary: Numerical experiences

In this paper we use the Isogeometric Analysis (IgA) to solve the Helmholtz equation with Dirichlet boundary condition over a bounded physical 2D domain. Starting from the variational formulation of the problem, we show how to apply IgA to obtain an approximated solution based on biquadratic B-spline functions. We focus the attention on problems where the physical domain has very irregular boundary. To solve these problems successfully a high quality parametrization of the domain must be constructed. This parametrization is also a biquadratic tensor product B-spline function, with control points computed as the vertices of a quadrilateral mesh with optimal geometric properties. We study experimentally the influence of the wave number and the parametrization of the physical domain in the accuracy of the approximated solution. A comparison with classical Finite Element Method is also included. The power of IgA is shown solving several difficult model problems, which are particular cases of the Helmholtz equation and where the solution has discontinuous gradient in some points, or it is highly oscillatory. For all model problems we explain how to select the knots of B-spline quadratic functions and how to insert knew knots in order to obtain good approximations. The results obtained with our imple-mentation of the method prove that IgA approach is successful, even on regions with irregular boundary, since it is able to offer smooth solutions having at the same time some singular points and high number of oscillations.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Mathematical Physic

Automatic procedure for mass and charge identification of light isotopes detected in CsI(Tl) of the GARFIELD apparatus

Mass and charge identification of light charged particles detected with the 180 CsI(Tl) detectors of the GARFIELD apparatus is presented. A \u2018\u2018tracking\u2019\u2019 method to automatically sample the Z and A ridges of \u2018\u2018Fast\u2013Slow\u2019\u2019 histograms is developed. An empirical analytic identification function is used to fit correlations between Fast and Slow, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products. A summary of the advantages of the proposed method with respect to \u2018\u2018hand-based\u2019\u2019 procedures is reported