1,721,087 research outputs found
Use of flashlamp-pumped pulsed dye laser in the treatment of superficial vascular malformations and ulcerated hemangiomas
No full textA retrospective study of 502 patients treated with tunable flashlamp pulsed dye laser for superficial vascular malformations (433), ulcerated hemangiomas (65) and postinvolutional redness (4) is presented. Patients were treated in the period from June 1997 to March 2006, with follow-up ranging from six months to four years. The age of the patients ranged from three months to 80 years. Correlation between clinical response and patients' age, location of lesion and number of treatments were evaluated in groups of superficial vascular malformations, whereas healing rates of the ulceration were assessed in a series of hemangiomas. The result were judged to be excellent in 51%, good in 39%, fair in 7% and poor in 3% of patients with vascular malformations. Excellent ultimate outcome confirmed the clinical efficacy of the use of the pulsed dye laser in the treatment of dermal vascular malformations, which also appears to have good prospects in the management of hemangioma complication
"Abilità descrittiva e coesione testuale in L1 e L2: lingue romanze e lingue germaniche a confronto".
No full textL'articolo tratta dei mezzi linguistici atti a creare la coesione discorsiva in testi di natura descrittiva (descrizione spaziale statica), confrontando un corpus di lingue germaniche (inglese, tedesco e svedese) ad un corpus di lingue romanze (italiano, francese e spagnolo). I dati analizzati consistono in produzioni testuali orali e comprendono sia testi in lingua materna (L1) sia testi in lingua seconda/straniera (L2).
Gli informatori hanno descritto un'immagine (tratta dalla serie Hier fällt ein Haus, dort steht ein Kran..., oder die Veränderung der Stadt di Jörg Müller, Verlag Sauerländer) ad un ascoltatore che non poteva vederla.
Il confronto interlinguistico conferma solo in parte quanto sostenuto da Carroll et al. (2000), e cioè che le opzioni linguistico-concettuali selezionate, in una certa lingua, per il mantenimento referenziale in un compito spaziale statico riflettono principi "language specific" differenti che sono associati a pattern di grammaticalizzazione altrettanto diversi. In contrasto, infatti, con questo studio, il mio evidenzia la necessità di affiancare ai diversi modelli di grammaticalizzazione, i differenti pattern di interazione adottati dalle svariate comunità linguistiche, i quali sembrano poter ugualmente influenzare in modo significativo le scelte concettuali e linguistiche operate dai parlanti nell'eseguire compiti verbali complessi.
Nella fattispecie, il mio studio conduce ai seguenti risultati:
a) i parlanti di lingue germaniche condividono alcuni strumenti avverbiali per la coesione testuale (ingl. here/ there; ted. hier/da/dort/daneben ecc.; sved. då/där/här/här/bredvid ecc.) che non sono invece impiegati dai parlanti nativi di lingue romanze, sebbene anche questi abbiano a disposizione, nel proprio vocabolario L1, alcuni strumenti equivalenti (it. qui/qua/lì/là/lì vicino..; fr. ici/là/là dessous..; sp. aquí/acá/ahí/allí/allá/aquí cerca..);
b) le strutture linguistiche che, in una certa lingua, riflettono i principi base dell’organizzazione discorsiva delle informazioni sono difficili da acquisire, in quanto l'apprendente deve riuscire ad identificare l’insieme di relazioni forma-funzione correlate ai diversi domini concettuali implicati rispetto ad un certo tipo di testo;
c) gli apprendenti tendono ad impiegare strumenti di coesione discorsiva vicini a quelli della L1, il che prova la loro difficoltà nel rivedere la prospettiva linguistico-cognitiva della propria lingua materna (Slobin 1996, 2003).
I dati in L1 dimostrano che le lingue germaniche si focalizzano – anche se in modo differente – sul concetto di “spazio” attraverso la selezione degli strumenti sopra citati, contrariamente ai parlanti di lingue romanze, che sembrano prestare una maggiore attenzione agli “oggetti” marcando il mantenimento referenziale attraverso i sintagmi preposizionali pieni o i loro equivalenti. Quanto ai dati in L2, essi mostrano come gli apprendenti modellino la selezione delle informazioni e degli strumenti di coesione linguistica attraverso la prospettiva “orientata verso lo spazio” o “verso gli oggetti” imposta dalla propria L1.
Carroll, Mary / Murcia, Jorge / Watorek, Marzena, / Bendiscioli, Sandra, 2000, “The relevance of information organisation to second language acquisition studies: the perspective discourse of advanced adult learners of German”. Studies in Second Language Acquisition, 22: 87-129.
Slobin, Dan I. (1996), “‘From thought and language’ to ‘thinking for speaking’”. In Gumperz, John J. / Levinson, Stephen C., Rethinking Linguistic Relativity, Cambridge, Cambridge University Press.
Slobin, Dan I., 2003, “Language and thought online: cognitive consequences of linguistic relativity”. In Gentner, D. / Goldin-Meadow, S. (eds.), Advances in the Investigation of Language and Thought, Cambridge, MA: MIT Press, 157-192
Polyethylene/layered‐silicate nanocomposite oriented fibers: morphology and mechanical characterization. In Abstracts from National Young Researchers' Forum on Materials Science and Technology, XIII AIMAT National Congress, National Biomaterial Congress - SIB, July 2016, Ischia, Italy
No full textOrgano-modified montmorillonite clay layers are able to improve not only mechanical properties but also heat resistance, barrier properties and flammability of polymeric matrixes. To this extent, processing parameters are important for non-polar polymers, like polyolefin, and compatibilizers are necessary to obtain exfoliated/intercalated morphologies. Polyethylene fibers are widely used due to the good achievable mechanical properties after drawing which can be further increased by the use of properly exfoliated nanoclays. The aim of this work was to produce nanocompos-ite polyethylene fibers oriented at different draw ratios and to correlate this processing parameters to morphology and mechanical properties of fibers produced at various clay loading
Physical and mechanical characterization of natural fibres and fabrics as reinforcement for composite systems
Full text linkIn recent years, the increasing interest in environmentally friendly materials has brought the attention of material technologists and civil engineers to natural fibres and their potential use in composite materials. Although several research activities have shown the good mechanical properties of these fibres, their use is still limited due to both the absence of standards and guidelines and some open durability issues highlighted in the literature. The present work is a contribution to identifying the main physical and mechanical properties of flax fibres and fabrics intended as internal reinforcement in composite materials with mineral matrix. Due to the lack of standardization on vegetal fibres as constituent of building materials, the experimental research moves from characterising the geometry of bundles. The diameter of single yarn and twisted bundles has been measured by means of a large number of measurements obtained by a microscope: specifically, six values have been recorded for each one of thirty specimens. A comparison with a most accurate SEM analysis has been performed as well. Tensile tests on single yarn, double yarn twisted bundle and textile strip specimens have been carried out. Tensile tests on flax textile have been performed after a specific curing period in controlled environment in order to evaluate the durability of the textile and its sensitivity to alkali agents. The results of the experimental activity showed that the diameter values assessed by means of a microscope are affected by the irregularities of the flax bundles, due to their twisted arrangement. Future developments will target the mechanical behaviour of Textile Reinforcing Mortar (TRM) composite systems based on a bidirectional grid fabric made of the aforementioned flax fibres: assessing the potential of these sustainable and reversible composites systems as a technical solution for in seismic strengthening of existing masonry members and structures is the final goal of this research
Development of recycled blown films based on post-consumer plastics recovered from seas and rivers
No full textPost-consumer flexible packaging abandoned in seas and rivers represent an important environmental problem: their recovery is still a challenge and the management of the recovered material is equally difficult since, due to their heterogenicity and to their long-time permanence in seas or rivers, these plastics present various issues related to high incompatibility, hygroscopicity and presence of bad smells. All this translates into poor processability and mechanical performance and low organoleptic quality. The aim of this work is to characterize the seas and rivers plastic waste (SRPW) composition and to perform a preliminary investigation on the effectiveness of two different mineral fillers as reinforcing and compatibilizing agents for SRPW, in view of possible second-life applications of this waste. In particular, an organo-modified montmorillonite (Dellite 67G) and a natural sodium zeolite mineral (Zeolite 4A), loaded at 5 wt%, were considered for improving the processability and properties of SRPW blown films. The combined use of a polymeric compatibilizer (polyolefin block copolymer grafted with 0.4 wt% maleic anhydride was also considered, in order both to improve the filler dispersion within the polymer and to compatibilize the main constituents of SRPW. The results demonstrated that the addition of both fillers to SRPW leaves essentially unchanged the thermal stability, but gives interesting improvements mainly in terms of stiffness. The effects are more significant when the nanometric Dellite 67G is added, than for the micrometric Zeolite 4A, especially in compatibilized systems
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