Search results for "carbon"

On the role of extensional flow in morphology and property modifications of MWCNT/polyamide-based fibres

2011

Unfilled and MWCNT-filled PA fibers are prepared and the effect of the extensional flow on their mechanical performance and morphological variations is investigated. Morphological analyses using SEM, TEM, and SAXS suggest a stronger orientation of the MWCNTs along the fiber direction with increasing extensional flow. A particular MWCNT bundle formation in the PA drawn nanocomposite fibers is observed for the first time, and a pull-out of the central nanotube in some bundles is noted. The maintenance of the “shish-kebab” structure upon extensional flow is responsible for the mechanical improvements and dimensional stability in MWCNT-filled PA fibers.

Determination of intrinsic scatter in lifetimes of carbon fibre epoxy pressure vessels in view of defining fundamental safety factors

2011

International audience

Preliminary results of fault-related permeability structures associated to the Scicli-Ragusa fault segments, Hyblean Plateau, Sicily

2010

Nella zona di Ragusa (Plateau Ibleo, Sicilia sud-orientale) la presenza di bitume all’interno di rocce carbonatiche di età oligo-miocenica, caratterizzate da una porosità primaria oggi compresa tra 0 e 10% (Formazione Ragusa, permette di osservare il ruolo esercitato da faglie e fratture nella circolazione degli idrocarburi. Con l’obiettivo quindi di effettuare studi mirati alla caratterizzazione petrofisica delle diverse tipologie di faglie e fratture affioranti, è stato condotto uno studio di terreno preliminare, che ha permesso la definizione dell’assetto geologico-strutturale della porzione occidentale del Plateau Ibleo, lungo il sistema di faglie denominato Scicli-Ragusa. Inoltre, sull…

Non-linear interactions of femtosecond laser pulses with graphene : photo-oxidation, imaging and photodynamics

2017

This thesis presents a study focused on interactions of femtosecond laser pulses with graphene, a one atom thick carbon membrane. Graphene, which exhibits exceptional electronic and optoelectronic properties, could provide considerable advantage over current silicon-based electronics. Graphene alone, being semi-metal, is not sufficient for electronic applications, but requires modification. For this, a set of methods for modifying and measuring the properties of graphene was developed. With the perspective of making graphene a suitable component for electronics, optoelectronics or photonics, ultrashort laser pulses were used for drawing patterns on graphene. The procedure modifies graphene …

How much can regional agri-environmental measures contribute to SOC stocking in the soils of Sicily?

2014

Soils have a great potential in stocking soil organic carbon SOC, but how much can human activities, and particularly agricultural ones, contribute to increase (or decrease) the SOC content? Which kind of agricultural practices are the most effective? From the soil database of Sicily we have selected 52 profiles, whose first 40 cm from the soil surface were analyzed for the SOC, of which 15 analyzed also for nitrogen N content, localized in the clayey hills and limestone marine terraces of the western Sicily, cultivated with grain crops and orchards (mainly olive groves and vineyards), surveyed and analyzed in a period from 1995 to 2008. By interviews to the farmers owners of those parcels,…

Fabrication of carbon nanotube field-effect transistors

2014

Finite element analysis of a Bionate ring-shaped customized lumbar disc nucleus prosthesis

2021

[EN] Study design: Biomechanical study of a nucleus replacement with a finite element model. Objective: To validate a Bionate 80A ring-shaped nucleus replacement. Methods: The ANSYS lumbar spine model made from lumbar spine X-rays and magnetic resonance images obtained from cadaveric spine specimens were used. All materials were assumed homogeneous, isotropic, and linearly elastic. We studied three options: intact spine, nucleotomy, and nucleus implant. Two loading conditions were evaluated at L-3-L-4, L-4-L-5, and L-5-S-1 discs: a 1000 N axial compression load and this load after the addition of 8 Nm flexion moment in the sagittal plane plus 8 Nm axial rotation torque. Results: Maximum nuc…

Degradation of Amino-(3-methoxyphenyl)methanephosphonic Acid by Alternaria sp

2002

Alternaria sp. isolated from the surface of carrot ( Daucus carota ) seeds appeared to be able to degrade amino-(4-methoxyphenyl)-methanephosphonic acid using it as a sole source of carbon, nitrogen, and phosphorus for growth.

‘Each flight is different’ : Carbon emissions of selected flights in three geographical markets

2017

Air travel is considered the biggest individual climate sin. Avoiding flying, however, seems impossible. In this paper we argue that the flight a passenger chooses can be significant. For this purpose we compared the carbon emissions of selected flights in three geographical markets. We found tremendous differences in the environmental performance of individual flights. Furthermore, we also found that flying with the most modern aircraft or flying non-stop represents, in many cases, the least polluting option. Nevertheless, we were able to show that there are exceptions to this rule. Based on our results, we provide recommendations to the industry and for further research. peerReviewed

Petrology and geochemistry of peri-Mediterranean carbonatite magmatism: case studies from Fuerteventura (Canary Islands) and Mt. Vulture volcano (sou…

2023

Carbonatites are rare magmatic rocks of great scientific and economic importance, and carbonatite magmatism is mainly associated with intraplate continental tectonic settings, with some rare occurrences in oceanic contexts. Despite their importance, many aspects of carbonatite petrogenesis and evolution processes remain still poorly constrained. In order to further constrain the mantle source and the storage system of carbonatite magmas, Fuerteventura (Canary Islands) was taken as a representative case study of oceanic carbonatites, while Mt. Vulture (southern Italy) was taken as a representative case study of intra-continental carbonatites, with a two-fold aim: to understand (i) the role o…