Search results for " TECNOLOGIA"
showing 10 items of 1359 documents
Graphene as a tunable resistor
2014
We present the design of a graphene-based electronically tuneable microstrip attenuator operating at a frequency of 5 GHz. The use of graphene as a variable resistor is discussed and the modelling of its electromagnetic properties at microwave frequencies is fully addressed. The design of the graphene-based attenuator is described. The structure integrates a patch of graphene, whose characteristics can range from being a fairly good conductor to a highly lossy material, depending on the applied voltage. By applying the proper voltage through two high-impedance bias lines, the surface resistivity of graphene can be modified, thereby changing the insertion loss of the microstrip attenuator.
Architectures for autism
2015
Le ricerche condotte sulle malattie degenerative della "terza età", hanno visto negli ultimi anni il gruppo di studio palermitano indagare e proporre soluzioni che vanno dalla stesura di linee guida per la progettazione di Residenze Sanitarie Assistenziali (RSA), alla progettazione esecutiva di architetture residenziali, al recupero e riuso di edilizia già esistente fino alla progettazione dello spazio domestico dedicato e protetto, che oltre a fornire risposte funzionali ne ha anche esaltato il design degli elementi di arredo. A questo ambito di ricerca da circa due anni si è affiancato un nuovo settore di indagine indirizzato sempre alle "minoranze sociali". Research conducted on degenera…
Application of Radio Environment Map Reconstruction Techniques to Platoon-based Cellular V2X Communications
2020
Vehicle platoons involve groups of vehicles travelling together at a constant inter-vehicle distance, with different common benefits such as increasing road efficiency and fuel saving. Vehicle platooning requires highly reliable wireless communications to keep the group structure and carry out coordinated maneuvers in a safe manner. Focusing on infrastructure-assisted cellular vehicle to anything (V2X) communications, the amount of control information to be exchanged between each platoon vehicle and the base station is a critical factor affecting the communication latency. This paper exploits the particular structure and characteristics of platooning to decrease the control information exch…
Processing and characterization of highly oriented fibres of biodegradable nanocomposites
2015
Abstract Biodegradable polymeric materials are becoming day by day ever more important in packaging, agriculture, single-use cutleries and other large consumer applications. The major part of those materials is used under the form of film, i.e. subjected to elongational flow, but the main problem is that they often offer poor mechanical properties. Adding nanofillers, like Multi Walled Carbon Nanotubes (MWCNTs) may solve this problem but only if there is a full control of their orientation inside the material. Aim of this work is to investigate the processing-properties-morphology relationships for a system prepared under elongation flow of MaterBi and commercial MWCNTs. The materials were …
Glass/basalt hybrid sandwiches for nautical applications
2011
Glass-basalt/epoxy hybrid composites for marine applications
2011
Abstract The aim of this work is to evaluate the influence of uniaxial basalt fabric layers on the mechanical performances of a glass mat/epoxy composite used for marine applications. Polymer composites, reinforced by glass mat (GFRP), and hybrid ones, reinforced by glass mat and unidirectional basalt fabric, have been produced by vacuum bagging technique. Three points bending and tensile tests have been carried out in order to evaluate the effect of number and position of basalt layers on the mechanical properties of the investigated structures. The experimental tests have showed that the presence of two external layers of basalt involves the highest increase in mechanical properties of hy…
The White Stone of South-Eastern Sicily: Urban and Territorial Identity
2017
La Sicilia è un territorio fortemente "segnato" dall'impiego massiccio della ricca varietà di materiali lapidei che la natura ha messo a disposizione: materia prima dalle differenti qualità petrografiche, colore, caratteristiche tecniche e con una vasta possibilità di impiego, sia come elemento costruttivo sia come pietra ornamentale. La "pietra bianca" di Siracusa, il basalto dell'Etna, la "pietra forte" del ragusano, la pietra di Sabucina di Caltanissetta e Niscemi, le calcareniti e le rocce tufacee delle cave di Carini e Aspra, il calcare grigio di billiemi nel palermitano e il tufo calcareo di Agrigento, caratterizzano gran parte degli insediamenti antropici dell'isola, espressione di u…
A review on basalt fibre and its composites
2015
Abstract In recent years, both industrial and academic world are focussing their attention toward the development of sustainable composites, reinforced with natural fibres. In particular, among the natural fibres (i.e. animal, vegetable or mineral) that can be used as reinforcement, the basalt ones represent the most interesting for their properties. The aim of this review is to illustrate the results of research on this topical subject. In the introduction, mechanical, thermal and chemical properties of basalt fibre have been reviewed. Moreover, its main manufacturing technologies have been described. Then, the effect of using this mineral fibre as reinforcement of different matrices as po…
Determining noise and vibration exposure in conifer cross-cutting operations by using Li-Ion batteries and electric chainsaws
2018
In many activities, chainsaw users are exposed to the risk of injuries and several other hazard factors that may cause health problems. In fact, environmental and working conditions when using chainsaws result in workers&rsquo
Holistic Approach to the Mediterranean Architectural Heritage at risk of abandonment: the case study of Montalbano Elicona (Italy)
2022
A conceptual and methodological renewal is needed in the field of formation, transformation and management of the built environment. This need also concerns the architectural heritage, a non-renewable resource threatened by various types of risk factors, including abandonment. A similar phenomenon (intended as a lack of usage, which leaves room for improper or harmful utilization) is juxtaposed with overuse (intended as too intense and continuous a usage), which today is even more unacceptable, due to the need for social distancing as part of the containment measures of COVID-19. There is a wide and varied case history regarding abandonment, with reference to possible causes and consequence…