1,721,213 research outputs found
Set documentale relativo all'approvvigionamento e montaggio del trasformatore e ausiliari
Full text linkQuesto rapporto è stato emesso nell'ambito del PAR2008-09 dell'accordo di programma ENEA-MSE e costituisce uno dei deliverable dell'obiettivo A "Prova integrale SPES-3" per reattori modulari di piccola-media taglia della linea progettuale LP2 "Reattori evolutivi" del teme di ricerca "Nuovo nucleare da fissione: collaborazioni internazionali e sviluppo competenze in materia nucleare". Il presente documento descrive le attività svolte da SIET per l'approvvigionamento ed il montaggio di un trasformatore AT/MT 10 MVA e dei relativi ausiliari, da installarsi nella sottostazione AT/MT d'utente in sostituzione del trasformatore fuori servizio (TR2) , nonché le attività pianificate entro la data contrattuale di fine lavori. In allegato al documento viene riportata la documentazione relativa all' espletamento della procedura negoziata per l'affidamento dei lavori di fornitura e messa in opera oggetto dell'appalt
Relazione tecnica intermedia sulla realizzazione della struttura portante dell'impianto SPES-3
Full text linkQuesto rapporto è stato emesso nell'ambito del secondo PAR dell'accordo di programma ENEA-MSE e costituisce uno dei deliverable dell'obiettivo A 'Prova Integrale IRIS - Realizzazione della struttura di supporto dell'impianto SPES3' della linea progettuale LP2 'Reattori Evolutivi INTD -International Near Term Deployment' del tema di ricerca 'Nuovo Nucleare da Fissione'. Il documento descrive l'attività effettuata per la realizzazione della struttura di sostegno dell'impianto SPES3. Inoltre il documento riporta negli allegati tutta la documentazione emessa relativa all' espletamento della procedura negoziata per l'affidamento dei lavori oggetto dell' appalto e all'esecuzione dei lavori
Set documentale relativo all'approvvigionamento e installazione dei componenti dell'impianto SPES-3
Full text linkQuesto rapporto è stato emesso nell'ambito del PAR2008-09 dell'accordo di programma ENEA-MSE e costituisce uno dei deliverable dell'obiettivo A "Prova integrale SPES-3" per reattori modulari di piccola-media taglia della linea progettuale LP2 "Reattori evolutivi" del tema di ricerca "Nuovo nucleare da fissione: collaborazioni internazionali e sviluppo competenze in materia nucleare". Il documento descrive le attività effettuate da SIET per la preparazione e l' espletamento della gara ai sensi del DLgs 163/2006 e s.m.i. per l'approvvigionamento ed installazione di componenti dell'impianto SPES3, nonché tutte le attività pianificate entro la data contrattuale di fine lavori. In allegato al documento viene riportata la documentazione relativa all'espletamento della procedura negoziata per l'affidamento dei lavori di fornitura e messa in opera oggetto dell'appalt
Investigation of CVD grown graphene topography
No full textIn this work, we combined AFM, FE-SEM and Raman spectroscopy to study the commercially available CVD grown graphene on Cu and Si substrate. SEM and AFM provide topographic information, show a network of out of plane deformations, 'wrinkles', whereas Raman spectroscopy which can give information on structural properties of the graphene films, such as the number of layers and level of disorder, by observing the peaks, indicates a I2D/IG ratio smaller than the value expected for mono-layer graphene. © 2018 Author(s)
DNA self-assembly on graphene surface studied by SERS mapping
No full textThe self-assembly of double-stranded DNA (dsDNA) segments on two variations of graphene surfaces having nano-platelets with different lateral sizes and thicknesses was investigated using surface-enhanced Raman spectroscopy (SERS) and electrical impedance spectroscopy (EIS) techniques. Due to the strong local field-enhancement, the SERS signals from functional molecules bound to the graphene edges and from DNA moieties were recorded. Relative intensities of specific Raman modes were used as contrast parameters to build Raman signal intensity maps. The observed variation in the SERS signal intensity was related to the different configuration (tilted or flattened) in which dsDNA segments are assembled on the carbon surface, depending on the graphene platelet size. EIS was used to characterize the conductive properties of nano-structured films containing pristine or DNA-functionalized graphene nano-platelets. Results from the EIS analysis supported the SERS findings and confirmed that SERS mapping is a reliable method for a rapid monitoring of the procedures used to interface DNA with graphene surfaces. The present study, linking DNA anchoring morphology to the conductive properties of nano-structured hybrid films, contribute to define a new approach in the optimization of biosensor design. © 2016 Elsevier Lt
Variability and functional role of chromosomal sequences in 16SrI-B subgroup phytoplasmas including aster yellows and related strains
No full textAims: Partial genetic characterization of several chromosomal regions on 35 16SrI-B phytoplasma strains maintained in periwinkle and collected in different geographical areas from plants of diverse species. Methods and Results: Genes coding for ribosomal protein rpL22, elongation factor EF-Tu and random cloned sequences amplified with primers AY19p/m, G35p/m and BB88F1/R1 after RFLP analyses showed a high degree of polymorphism among the strains studied. The ribosomal protein (rp) subgroups B and K, and an undescribed subgroup designated N, were identified. Amplicons obtained with primers AY19p/m and BB88F1/R1, revealed a high and a low degree of polymorphism, respectively. Conclusions: A probable spacer role could be attributed to the AY19p/m sequence and a possible coding function to the BB88F1/R1 sequence. No relationship was found among genetic polymorphisms, identified by statistical analyses, and epidemiological or biological parameters. Significance and Impact of the Study: The analyses of five different genomic sequences of the 35 strains belonging to subgroup 16SrI-B allowed a finer distinction among them, confirming that the polymorphism level of 16S rDNA is too low to be adopted as unique parameter for classification
Fracture mechanisms in epoxy composites reinforced with carbon nanotubes
No full textRecent advances in nanotechnology and nanostructured materials offer the possibility to improve the mechanical properties of composite structures in terms of toughness and stiffness. In particular, in aerospace applications research efforts are focused on the design of advanced composite materials reinforced with carbon nanotubes (CNTs) that combine weight saving with multifunctional properties, including thermal, mechanical and electromagnetic ones. It is well known that carbon nanoparticles enhance the fracture strength, the modulus, and the yield strength of a polymer matrix through different mechanisms. However, despite the large amount of investigations on CNT-based composites and their relevant properties, there is a lack of understanding of the mechanisms leading to the failure of these materials under impact or static loads, which limits their use in practical applications. In this work, we present an experimental investigation of the fracture mechanisms of aerospace grade epoxy composites reinforced with multi-walled CNTs bridging the mechanical characterization with non-destructive methods, such as optical spectroscopy and electron microscopy. Our results show that it is possible to link the failure mechanisms of the nanostructured composite at the interface between the CNT and the epoxy matrix, namely cracking, pull-out and telescopic failure, with the molecular fingerprint of the carbon structure at the fracture surface after mechanical testing. © 2014 The Authors. Published by Elsevier Ltd
Graphene/DNA nanostructured films for bioinspired sensing of UV radiation effects
No full textBio-based sensor nanotechnology is a fast growing field that can provide efficient solutions to monitor radiation effects in space environment. In our research we investigate the integration of UV-sensitive biological recognition elements, such as DNA, in carbon-based hybrid nanomaterials for the fabrication of miniaturized and light-weight sensors that can be used to monitor the biological effects of hostile ultraviolet radiation in space. In particular, in this paper we present results on the fabrication and characterization of hybrid nanostructured films containing graphene material and DNA strands for an in-situ and real time detection of UV radiation damaging effects from changes of the film electrical properties. The biosensing graphene/DNA units are embedded in a UV-transparent polymeric matrix based on silicon polymers, which allows for the fabrication of flexible films with high thermal stability. Copyright © 2014 by the International Astronautical Federation. All rights reserved
Surface-enhanced Raman spectroscopy characterisation of functionalised multi-walled carbon nanotubes
No full textMulti-walled nanotube (MWNT) functionalisation was investigated by surface-enhanced Raman spectroscopy (SERS). The MWNTs were deposited as dilute dispersions on SERS-active substrates. We used nano-structured gold surfaces with various morphologies for our measurements. The surface enhancement effect was used to amplify the Raman signal from functional molecules bound to the nanotube walls. The recorded spectral features allowed for discrimination between the differently functionalised MWNTs. Although the present study is limited to a few examples, our measurements indicate the higher specificity obtained by the SERS approach and its possible use for a systematic study of functionalisation effects on MWNT structures. © the Owner Societies 2015
- …
