1,744 research outputs found
Traduzione
Il tema della traduzione è stato centrale in filosofia analitica del linguaggio perché strettamente legato al problema del significato. Lo scopo di questo articolo è quello di presentare e discutere criticamente le principali teorie della traduzione, mostrando le difficoltà a cui sono andate incontro le varie definizioni di traduzione. Da una parte si cercherà di capire perché la definizione di traduzione in base ad altri concetti, come quello di significato o di equivalenza, abbia portato ad esiti paradossali. D’altra parte, si cercherà di mostrare perché questi esiti non siano così drammatici e come invece questa nozione sia utile a chiarire i meccanismi più profondi sottesi alla comprensione del linguaggio e ai fenomeni linguistici sia di tipo semantico che pragmatico
Gram scale synthesis of the C(18)-C(34) fragment of amphidinolide C.
The synthesis of the C(18)-C(34) fragment of amphidinolide C has been achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. The highly convergent approach will facilitate the synthesis of analogues, including the C(18)-C(29) fragment of amphidinolide F. Synthetic highlights include the selective methylation of a diyne, and the highly efficient use of a second generation cobalt catalyst in the Mukaiyama oxidative cyclization to form the trans-THF ring
Gram scale synthesis of the C(1)-C(9) fragment of amphidinolide C
An allylic cis-epoxide prepared by Sharpless asymmetric epoxidation was transformed in 9 steps and 41% overall yield to the cyclization precursor 4 via a key one carbon homologation. Cobalt catalyzed aerobic oxidative cyclization of 4 gave the trans-THF in 94% yield at gram scale. Subsequent manipulations, including a Still-Gennari olefination, Sharpless asymmetric dihydroxylation, Corey-Fuchs alkynylation and Kazmaier hydrostannylation provided the fully functionalized C(1)-C(9) fragment 2 suitable for cross coupling. The sequence is readily scalable and provides gram quantities of
Geochemical characteristics and mantle sources of the Oligo-Miocene primitive basalts from Sardinia: The role of subduction components.
During the Oligo-Miocene, the Island of Sardinia was covered by the products of voluminous magmatic activity, with a typical subduction-related signature. The mafic rocks of the Montresta (north) and Arcuentu (south) volcanic districts include primitive high MgO basalts whose trace element and Sr-, Nd- and Pb-isotope compositions constrain the nature and role of subduction-related components in the Tertiary Sardinian volcanism. The geochemical and isotopic data require an approximate degree of partial melting of 15% of a MORB-like depleted mantle prior to enrichment, and the input of two subduction components in the mantle wedge consisting of fluids from subducted oceanic crust (altered MORB) and fluids from subducted sediments. Ratios among trace elements which are variably compatible with fluid and melt phases (i.e. Th/Pb, Th/Nd and Sr/Nd) exclude the contribution of melts from the subducted slab. Models based on isotopic ratios indicate that the pre-subduction depleted mantle source of Sardinia magmas was enriched by 0.1-0.5% MORB fluid and less than 0.1% sediment fluid. The geochemical and isotopic compositions of the Montresta volcanic rocks are homogeneous, whereas those of the Arcuentu show quite heterogeneous characters, suggesting variations in mantle source over the long time-span (about 13 Ma) of volcanic activity in this district
The Geochemistry of the melilite-bearing lavas of the Nyiragongo volcanic complex (D.R. Congo)
Pacific Plate slab pull and intraplate deformation in the early Cenozoic
Large tectonic plates are known to be susceptible to internal deformation, leading to a range of phenomena including intraplate volcanism. However, the space and time dependence of intraplate deformation and its relationship with changing plate boundary configurations, subducting slab geometries, and absolute plate motion is poorly understood. We utilise a buoyancy driven Stokes flow solver, BEM-Earth, to investigate the contribution of subducting slabs through time on Pacific Plate motion and plate-scale deformation, and how this is linked to intraplate volcanism. We produce a series of geodynamic models from 62 to 42 Ma in which the plates are driven by the attached subducting slabs and mantle drag/suction forces. We compare our modelled intraplate deformation history with those types of intraplate volcanism that lack a clear age progression. Our models suggest that changes in Cenozoic subduction zone topology caused intraplate deformation to trigger volcanism along several linear seafloor structures, mostly by reactivation of existing seamount chains, but occasionally creating new volcanic chains on crust weakened by fracture zones and extinct ridges. Around 55 Ma subduction of the Pacific-Izanagi ridge reconfigured the major tectonic forces acting on the plate by replacing ridge push with slab pull along its north-western perimeter, causing lithospheric extension along pre-existing weaknesses. Large scale deformation observed in the models coincides with the seamount chains of Hawaii, Louisville, Tokelau, and Gilbert during our modelled time period of 62 to 42 Ma. We suggest that extensional stresses between 72 and 52 Ma are the likely cause of large parts of the formation of the Gilbert chain and that localised extension between 62 and 42 Ma could cause late-stage volcanism along the Musicians Volcanic Ridges. Our models demonstrate that early Cenozoic changes in Pacific plate driving forces only cause relatively minor changes in Pacific absolute plate motions, and cannot be responsible for the Hawaii-Emperor Bend (HEB), confirming previous interpretations that the 47 Ma HEB does not reflect an absolute plate motion event
Rockfall threatening cumae archeological site fruition (Phlegraean fields park—naples)
Natural hazards threaten many archaeological sites in the world; therefore, susceptibility analysis is essential to reduce their impacts and support site fruition by visitors. In this paper, rockfall susceptibility analysis of the western slope of the Cumae Mount in the Cumae Archaeological Site (Phlegraean Fields, Naples), already affected by rockfall events, is described as support to a management plan for fruition and site conservation. Being the first Greek settlement in southern Italy, the site has great historical importance and offers unique historical elements such as the Cumaean Sibyl’s Cave. The analysis began with a 3D modeling of the slope through digital terrestrial photogrammetry, which forms a basis for a geomechanical analysis. Digital discontinuity measurements and cluster analysis provide data for kinematic analysis, which pointed out the planar, wedge and toppling failure potential. Subsequently, a propagation-based susceptibility analysis was completed into a GIS environment: it shows that most of the western sector of the site is susceptible to rockfall, including the access course, a segment of the Cumana Railroad and its local station. The work highlights the need for specific mitigation measures to increase visitor safety and the efficacy of filed-based digital reconstruction to support susceptibility analysis in rockfall prone areas
La durabilit\ue0 dei componenti edilizi
La pubblicazione riporta una sintesi dei risultati della ricerca scientifica nazionale (PRIN-2003) su \u201cMetodologie di progettazione e di valutazione della durabilit\ue0 dei componenti edilizi in processi di produzione sostenibili, finalizzate alla programmazione della manutenzione degli edifici\u201d delle sei unit\ue0 di ricerca (Politecnico di Milano, Politecnico di Torino, Universit\ue0 degli Studi Federico II di Napoli, Universit\ue0 degli Studi di Palermo, Universit\ue0 degli Studi di Catania, Universit\ue0 degli Studi di Brescia).
La ricerca \ue8 condotta in coerenza con quanto si sta sviluppando a livello internazionale nell\u2019ambito dell\u2019International Council for Research and Innovation in Buiding and Construction (CIB), in particolare nella Commissione CIB W80 Prediction of Service Life of Building Materials and Components, nonch\ue9 nei correlati lavori dell\u2019ISO TC 59 SC14 per l\u2019elaborazione delle varie parti della norma ISO 15686 \u201cService life planning\u201d.
Il lavoro ha portato nel 2006 alla uscita della prima norma italiana UNI 11156 \u201cValutazione della durabilit\ue0 dei componenti edilizi\u201d articolata in tre parti: \u201cTerminologia e definizione dei parametri di valutazione\u201d, \u201dMetodi per la valutazione della propensione all\u2019affidabilit\ue0\u201d, \u201dMetodi per la valutazione della durata\u201d.
I risultati finora acquisiti costituiscono gi\ue0 un significativo riferimento per gli operatori di committenza pubblica e privata in interventi edilizi di nuova costruzione ai fini di organizzare per essi una manutenzione programmata atta ad assicurare nel tempo il mantenimento di un livello di qualit\ue0 tecnologica adeguato, con benefico effetto di riduzione dei costi di gestione degli edifici.
Ci\uf2 potr\ue0 essere perseguito attraverso la conoscenza della qualit\ue0 tecnologica utile dei componenti edilizi dei componenti edilizi richiedibile attraverso le specifiche di durabilit\ue0 direttamente imponibili da parte dei progettisti nei capitolati speciali d\u2019appalto secondo i dettati della sopra citata norma UNI 11156
Assessing Yield and Quality of Melon (Cucumis melo L.) Improved by Biodegradable Mulching Film
: Low-density polyethylene (LDPE) plastic mulching films have an important function, but at the end of their lifetime pose an economic and environmental problem in terms of their removal and disposal. Biodegradable mulching films represent an alternative to LDPE with the potential to avoid these environmental issues. In this preliminary study, we employed a biodegradable film based on Mater-Bi® (MB) in comparison with low-density polyethylene to assess their effect on the yield and particular quality traits (organoleptic and nutraceutical composition of the fruits) of muskmelon (cv Pregiato) grown on soils with different textures (clay-loam-CL and sandy loam-SL) in two private farms in South Italy. Soil temperature under the mulch was also measured. During the monitored periods, mean soil temperature under LDPE was higher (about 1.3 °C) than that under the biodegradable film and was higher in SL soil than in CL soil, at 25.5° and 24.2 °C, respectively. However, the biodegradable film was able to limit the daily temperature fluctuation, which was 1.7 °C in both soils compared with 2.3 °C recorded for LDPE. Fruit yields were higher with MB film than LDPE (+9.5%), irrespective of soil texture. MaterBi® also elicited increases in total soluble solids, polyphenols, flavonoids, and antioxidant activity compared with LDPE films: 13.3%, 22.4%, 27.2%, and 24.6%, respectively. Color parameters of flesh, namely brightness, chroma, and hue angle were better in fruits grown on LDPE. Our findings suggest that Mater-Bi® based biodegradable mulching film is a potentially valid alternative to traditional LDPE, particularly for obtaining the agronomical benefits outlined above and for promoting environmental sustainability due to its favourable biodegradable properties
Short-term signals of climate change in Italian summit vegetation: observations at two GLORIA sites
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