Search results for "Glass"

Orientational glass behaviour of K Br0.96(CN)0.04

1981

Ultrasonic measurements on the mixed crystal K Br0.96(CN)0.04 show a minimum of most of the elastic constants at 16 K. In addition we determinedc11(T) at 10 MHz and at 50 MHz observing dispersion effects. These results and previous Brillouin and neutron scattering results of other authors on higher CN-concentrations are interpreted by an orientational glass behaviour. A semiquantitative description is given in terms of the mean random field approximation.

ARCHITECTURE AND PHOTOVOLTAICS. Strategies, technologies and novel components for the building envelope

Il principale obiettivo della tesi ha riguardato lo studio di strategie e tecnologie per l’integrazione del fotovoltaico negli edifici, con particolare attenzione verso le tecnologie solari di terza generazione, e la successiva definizione di un componente multifunzionale innovativo per l’involucro edilizio integrato con Dye-sensitized Solar Cells (DSC). Nella prima parte del lavoro, la ricerca si è concentrata sull’analisi del mercato del Building Integrated Photovoltaics (BIPV), sottolineando differenze, limiti e potenzialità di ciascuna tecnologia fotovoltaica. Particolare attenzione, inoltre, è stata rivolta a un numero consistente di casi studio, ossia edifici di nuova costruzione o in…

Benefits of a translucent building envelope made of DSC-integrated glass blocks

2015

The aim of this paper is to analyse the benefits deriving from the replacement of the glazed façades of an office building located in Palermo (Sicily) with a new translucent BIPV envelope made of multifunctional glass block panels integrated with Dye-sensitized Solar Cells (DSCs). The analysed 11-storey building is cladded by a curtain wall determining high management costs, especially during summer, in order to maintain indoor comfort. After the design of the building envelope and of the components for the connection of the glass block panels with existing load bearing structure, the energy performance of the building, before and after the replacement of its envelope, were analysed with th…

The one loop gluon emission light cone wave function

2017

Light cone perturbation theory has become an essential tool to calculate cross sections for various small-$x$ dilute-dense processes such as deep inelastic scattering and forward proton-proton and proton-nucleus collisions. Here we set out to do one loop calculations in an explicit helicity basis in the four dimensional helicity scheme. As a first process we calculate light cone wave function for one gluon emission to one-loop order in Hamiltonian perturbation theory on the light front. We regulate ultraviolet divergences with transverse dimensional regularization and soft divergences with using a cut-off on longitudinal momentum. We show that when all the renormalization constants are comb…

Unequal rapidity correlators in the dilute limit of the JIMWLK evolution

2019

We study unequal rapidity correlators in the stochastic Langevin picture of Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner (JIMWLK) evolution in the color glass condensate effective field theory. We discuss a diagrammatic interpretation of the long-range con elators. By separately evolving the Wilson lines in the direct and complex conjugate amplitudes, we use the formalism to study two-particle production at large rapidity separations. We show that the evolution between the rapidities of the two produced particles can be expressed as a linear equation, even in the full nonlinear limit. We also show how the Langevin formalism for two-particle correlations reduces to a Balitsky-Fadin…

Hyaluronic Acid–Silica Nanohybrid Gels

2013

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling…

Disequilibrium carbon and oxygen isotope fractionation in recent cave calcite: Comparison of cave precipitates and model data

2013

Abstract Speleothem proxy data provide important information in continental palaeo-climate research due to their precise chronology and wide geographic distribution. Despite a continuously growing number of field and numerical studies designed to study stable isotope fractionation effects, many aspects remain a matter of debate. Here, carbon and oxygen isotope ratios from cave drip water and calcite precipitates sampled on watch glasses in the Bunker Cave (Western Germany) are compared with the values expected for isotopic equilibrium. Furthermore, the field data are compared with the results of a numerical model simulating stalagmite growth and stable isotope ratios. Two drip sites with di…

Origin of clay minerals in soils on pyroclastic deposits in the island of Lipari (Italy)

2005

The island of Lipari (Italy) is characterized by calc-alkaline to potassic volcanism and a Mediterranean-type climate. The mineralogical and chemical features of two different soil profiles with ages of 92,000 and 10,000–40,000 y, respectively, have been investigated. There were no Andisols, but Vitric and Vertic Cambisols have developed at both sites. Although the morphology of the soils was similar, remarkable differences in the clay mineralogy between the two sites were observed. The site with the Vitric Cambisol was associated with the weathering sequence: glass → halloysite → kaolinite or interstratified kaolinite-2:1 clay minerals. Both sites had smectite in the clay fraction and, to …

Dynamic thermal expansivity near the glass transition

2000

Dielectric techniques were used to investigate the thermal expansivity of polystyrene films. Capacitive scanning dilatometry (CSD) employs temperature ramping in order to monitor the non-linear structural relaxation in the glass transformation range and to quantify liquid fragility. In the linear response regime, the complex thermal expansivity is obtained as a function of the temperature cycling frequency and is observed to reflect the structural relaxation.

Sensor Properties of Pristine and Functionalized Carbon Nanohorns

2016

Nanodispersions of pristine single-wall carbon nanohorns (i.e., p-SWCNHs) and oxidized-SWCNHs (i.e.; o-SWCNHs) were used to modify screen printed electrode (SPE). p-SWCNHs and o-SWCNHs were fully characterized by using several analytical techniques, as: HR-TEM (High Resolution-Transmission Electron Microscopy), FE-SEM/EDX (Field Emission-Scanning Electron Microscopy/Energy Dispersive X-ray Analysis), Raman spectroscopy, thermogravimetric analysis, differential thermal analysis (DTA), and the Brunauer-Emmett-Teller (BET) method. The chemically modified SPEs were also characterized with Cyclic Voltammetry (CV), using several different electro-active targets. In all cases, p-SWCNHs showed bett…