Search results for " fisica"

Ce:YAG composites for white LED

2015

Composites and luminescent polymers have been recently found to be potential candidates for the development of white LED, lasers and luminescent concentrators for solar cells. Due to its luminescence properties YAG doped with lanthanides ions is a good candidate as light emitting filler. In a recent our work, the preparation of a polymeric nanocomposite containing Ce:YAG nanoparticles using in situ polymerization has been reported [1]. A good dispersion of Ce:YAG nanoparticles has been obtained maintaining them luminescence properties. In addition, an increase of thermal stability and stiffness of PMMA was observed [2]. Then, the preparation of Ce:YAG-PMMA composite has been performed by us…

Polymeric Ce:YAG nanocomposites: synthesis and characterization

2015

These last years, the development of hybrid polymer-inorganic nanocomposites has been attracted much attention. In particular, composites containing lanthanide-doped materials as filler are candidates for the development of light emitting diodes, lasers and solar cells. Polymers such as polymethylmethacrylate (PMMA), polycarbonate (PC) and polyurethane (PU) are adequate matrices because their good transmission over the visible spectral range, excellent mechanical properties of plasticity, lightness, easiness of fabrication and low cost of mass production. Yttrium aluminum garnet (YAG) doped with Ce(III) ions is one of the yellow phosphor used in the major commercial white LED combined with …

Resonances in the solar system

2010

We give a description of orbital and spin-orbit resonances in the solar system, providing several examples which include planets, satel- lites, asteroids, rings, Kuiper objects.

Pyrazole[3,4-d]pyrimidine derivatives loaded into halloysite as potential CDK inhibitors

2021

Uncontrolled cell proliferation is a hallmark of cancer as a result of rapid and deregulated progression through the cell cycle. The inhibition of cyclin-dependent kinases (CDKs) activities is a promising therapeutic strategy to block cell cycle of tumor cells. In this work we reported a new example of nanocomposites based on halloysite nanotubes (HNTs)/pyrazolo[3,4-d]pyrimidine derivatives (Si306 and Si113) as anticancer agents and CDK inhibitors. HNTs/Si306 and HNTs/Si113 nanocomposites were synthesized and characterized. The release kinetics were also investigated. Antitumoral activity was evaluated on three cancer cell lines (HeLa, MDA-MB-231 and HCT116) and the effects on cell cycle ar…

Accordo di Programma MSE-CNR - Gruppo tematico: Celle a Combustibile (wp1) Responsabile scientifico del Progetto Vincenzo Antonucci - Accordo di Coll…

2010

Accordo di Programma MSE-CNR. Gruppo tematico: Celle a Combustibile (wp1). Responsabile scientifico del Progetto Vincenzo Antonucci. Accordo di Colla…

2011

(H, ρ)-induced dynamics and the quantum game of life

2017

Abstract We propose an extended version of quantum dynamics for a certain system S , whose evolution is ruled by a Hamiltonian H, its initial conditions, and a suitable set ρ of rules, acting repeatedly on S . The resulting dynamics is not necessarily periodic or quasi-periodic, as one could imagine for conservative systems with a finite number of degrees of freedom. In fact, it may have quite different behaviors depending on the explicit forms of H, ρ as well as on the initial conditions. After a general discussion on this (H, ρ)-induced dynamics, we apply our general ideas to extend the classical game of life, and we analyze several aspects of this extension.

I ‘vasi di Centuripe’: per un approccio integrato

2017

Il contributo intende evidenziare le prospettive di un approccio interdisciplinare integrato allo studio della ceramica policroma “di Centuripe”. Dagli inizi del XX secolo, tale classe ha riscosso ampio apprezzamento per le sue delicate pitture e la ricchezza di ornamenti a rilievo applicati (dipinti e dorati) che abbelliscono i vasi, rendendoli pressoché inutilizzabili nella pratica per scopi funzionali, ma altamente efficaci come doni funerari in antico, e oggi come pezzi di grande impatto per commercianti di antichità e collezionisti moderni. Data la piaga, diffusa fino a tempi recenti, degli scavi clandestini, dei “restauri” arbitrari e delle falsificazioni, i vasi di Centuripe necessit…

Coprecipitation synthesis of Nd:YAG nanopowders II: the effect of Nd dopant addition the on Luminescence Properties

2009

Abstract Nanopowders of Yttrium Aluminium Garnet (Y3Al5O12, YAG) doped with neodymium (Nd:YAG, 0.2–24.0 at.%) were prepared using the co-precipitation method followed by an annealing treatment up to 950 °C. For a concentration of neodymium lower than 3.2 at.% the materials were found constituted by the garnet phase according to X-ray diffraction investigations. However, at higher neodymium loading the hexagonal and monoclinic forms of yttrium aluminium oxides were found together with the garnet phase. For Nd quantity lower than 0.8% the luminescence emission spectra appear to be nearly the same, indicating that in the examined range of composition the immediate surrounding of the emitting N…

Electrosynthesis of Ce–Co Mixed Oxide Nanotubes with High Aspect Ratio and Tunable Composition

2008

Cerium oxide and cobalt oxides have attracted the interest of several researchers due to their potential application in several technological fields electrochromism, lithium batteries, catalysis, etc.. Ceria has been used as a promoter in the so-called “three-way catalyst” for the control of toxic emission from automobile exhaust. The promotion consists of the enhancement of the noble metal dispersion, as well as stabilization of the supporting medium toward thermal sintering. 1,2 A direct catalytic effect of CeO2 in chemical processes such as water–gas shift reaction or NOx decomposition has been also evidenced. 3,4