Search results for "UAS"

Carbon and safe-haven flows

2022

<abstract> <p>This paper explores the role of European Union Allowances (EUAs) as a safe haven for a range of assets and analyses the effect of safe-haven flows on the European carbon futures market. In particular, we demonstrate that EUAs can be considered a refuge against fluctuations in corporate bonds, gold and volatility-related assets in periods of market turmoil. Furthermore, we have shown that extremely bearish and bullish movements in those assets for which the EUA acts as a safe haven induce excess volatility in carbon markets, higher carbon trading volume and larger than normal EUA bid-ask spreads. These findings support the idea that some traders, by considering carb…

Alkane dehydrogenation on defective BN quasi-molecular nanoflakes: DFT studies

2020

Lower alkanes are feedstocks readily available but relatively inert. The con- version of low cost alkanes to industrially relevant alkenes is usually carried out on metal-based heterogeneous catalysts. Considering both the cost and the potential harmfulness of the metal involved in the dehydrogenation cat- alysts (typically, platinum or chromium), the study of metal-free processes represents an important challenge for the industrial chemistry in order to address more sustainable protocols and different routes either to activate or transform alkanes. Framed in this context, it was investigated, using a den- sity functional theory approach, the potential dehydrogenation activity of de- fectiv…

QENS investigation of filled rubbers

2002

The polymer segmental dynamics is investigated in a series of silica-filled rubbers. The presence of inert fillers in polymers greatly affects the mechanical and physical performance of the final materials. For example, silica has been proposed as a reinforcing agent of elastomers in tire production. Results from quasielastic neutron scattering and Dynamic Mechanical Thermal Analysis (DMTA) measurements are presented on styrene–ran-butadiene rubber filled with silica. A clear indication is obtained of the existence of a bimodal dynamics, which can be rationalized in terms of the relaxation of bulk rubber and the much slower relaxation of the rubber adsorbed on the filler surface.

Quasielastic neutron scattering study of dynamics at the crossover from dilute to semidilute behavior in polymer solutions

1982

STUDIES OF STRUCTURE AND DYNAMICS OF SOLID POLYMERS BY ELASTIC AND INELASTIC NEUTRON SCATTERING

1979

Neutron scattering methods can be applied to solid polymers in order to investigate the structure of the bulk material as well as the nature of the molecular motion. A review of some recently performed studies is presented. Diffusional motion in crystals of chain molecules has been studied by means of quasielastic scattering for the case of n-C33H68 as an example for the relationship between structure and molecular motion. It can be shown that below the so-called rotational transition the paraffin crystals exhibit two types of molecular motion: a translational jump (τt = 0.5 10-8s) and a 180°-rotational jump (τr = 2.5 10-8s). The low frequency vibrations in n-alkanes as models of polyethyle…

Chemical structure and internal diffusion within polymer chains in the melt

1985

The single chain dynamics of polydimethylsiloxane in the melt is studied by means of quasielastic neutron scattering. For this polymer the wave vector range 0.03 A−1≦q≦0.30 A−1 covers the regime of universal modes as well as local diffusive processes. A model is described which incorporates the specific chemical structure of the macromolecule and allows to interpret our data in the full wave vector regime. The only parameter which enters the model, the monomer diffusion constantDm, is found to be (1.2±0.2)·10−5 cm2s−1.

Random quasi-phase-matched second harmonic generation in periodically poled lithium tantalate

2009

We experimentally observed and explained bulk second harmonic generation via random quasi-phase-matching, derived from a periodically poled lithium tantalate sample with a randomly patterned mark-to-space-ratio.

Acquasantiera (Gangi, chiesa Madre di San Nicolò)

2011

L’acquasantiera in marmo bianco della chiesa madre di Gangi proviene dalla chiesa del monastero benedettino di Santa Maria di Gangivecchio e può ricondursi alla metà del XVI secolo.

Processi di integrazione e digitalizzazione dei servizi della P.A. orientate al riconoscimento della domanda dei denizenship della popolazione migran…

2023

Il case study analizzato descrive l'esperienza avviata all'interno degli uffici Comune di Palermo dall’equipe pluridisciplinare del progetto FAMI Mi.Main (Migration Mainstreaming), al fine di favorire la denizenship della popolazione migrante. Evidenzia come l'implementazione di servizi di facilitazione della comunicazione interculturale (1) e l’uso di nuovi strumenti di comunicazione digitale (2) hanno concretamente rafforzato la risposta della P.A. alle richieste di cittadinanza della popolazione migrante. The analyzed case study describes the experience started within the Municipality of Palermo offices by the multidisciplinary team of the FAMI Mi.Main (Migration Mainstreaming) project, …

Intercultural Communicative Competence as a Tool for Autonomous Learning

2010

In recent years the concept of intercultural communicative competence (ICC) has started to spread in the field of foreign language teaching and learning. ICC is based on the development by the learner of several “savoirs” concerned with attitudes and values, knowledge, skills of interpreting and relating, skills of discovery and interaction and critical cultural awareness. In ICC, students become the centre of the teaching and learning process and the role of teachers should be focused on encouraging autonomous and independent learning skills in their students. En los últimos años el concepto de competencia comunicativa intercultural (CCI) ha comenzado a extenderse en el campo de la enseñan…