Search results for "ceramic"
showing 10 items of 2129 documents
Non-covalent graphene nanobuds from mono- and tripodal binding motifs.
2017
Graphene nanobuds were prepared via the non-covalent anchoring of C60-based molecules endowed with one or three pyrene units, respectively. TGA, FTIR, UV-Vis and TEM investigations confirmed the formation of nanohybrids. For the two molecular derivatives, striking differences were determined in their interaction with graphene or carbon surfaces by Raman, cyclic voltammetry and molecular mechanics calculations, revealing the important role of pyrene adsorption in modulating the electronic properties of the nanohybrids.
Rhodium catalyzed oxidative coupling of salicylaldehydes with diazabicyclic olefins: a one pot strategy involving aldehyde C–H cleavage and π-allyl c…
2013
An efficient one pot strategy for the synthesis of cyclopentene fused chromanone derivatives through the direct oxidative coupling of salicylaldehydes with bicyclic olefins in the presence of a rhodium-copper catalyst system is described. This is the first report on the ring opening-ring closing of bicyclic hydrazines via metal catalyzed oxidative coupling reaction.
Bell Beakers in the southeast of France. From Archaeology to History of the third millenium BC
2002
The term "Bell Beaker", in the strict sense, designates a ceramic beaker form with an S-shaped profile that gives it the shape of an inverted bell. This type of drinking-vessel is characterized by both its very particular pattern of decoration and by the generally skilled execution of that decoration. By extension, the decoration characteristic of these beakers bas allowed the expansion of the category "Bell-Beaker" to include other pottery forms and even other types of decoration showing the same tradition, vvhich probably represent an evolution or reproduction of the original Bell Beaker pattern, The recognition of these objects and their definition as a class date to the nineteenth centu…
TYPO-CHRONOLOGIE DES CÉRAMIQUES DU GROUPE RHIN-SUISSE-France -ORIENTALE (R.S.F.O.) DANS LA RÉGION DIJONNAISE :
2009
The archaeological site of the Pré-du-Plancher is located to the east of Dijon (Burgundy, Côte-d’Or), at the footof a limestone hill in the Basmont valley. This site, dated from the late Bronze Age, is the first to include a stratigraphicalsequence for this period in Burgundy. The settlement comprises of three buildings and several dumps containing potteryfinds. The study of the pottery as well as the site’s stratigraphy clearly identifies three chronological periods dating from Late Bronze Age IIb to Late Bronze age IIIa (French chronology) or Hallstatt A2 / B1 (German/Swiss chronology). Culturally, the site belongs to the Rhin-Suisse-France-Orientale group, the first phase showing influen…
Ceramiche di produzione locale e ceramiche di importazione nella Sicilia tardo antica
2000
Sustainable recycling technologies for thermoplastic polymers and their composites: A review of the state of the art
2022
This review article discusses the environmental and economic effects of recycling, as well as sustainable thermoplastic polymer recycling technologies. Several researchers have utilized recycled thermoplastics as matrices in the production of a variety of natural and synthetic-based composites, which is also the focus of this study. All of the industries (food and packaging, construction and building, transportation, and indoor usage) where recycled thermoplastics have a large market share (food and packaging, construction and building, transportation, and indoor usage) are covered in this review. The desirable properties of thermoplastic polymers, such as corrosion resistance, low density,…
Materiali ceramici di importazione africana dalla catacomba di Villagrazia di Carini. Un aggiornamento sulla circolazione nel territorio della eccles…
2012
Primo volume della Collana "Quaderni Digitali di Archeologia Postclassica". La catacomba di Villagrazia di Carini è uno dei principali monumenti del primo Cristianesimo siciliano, cimitero di una comunità agiata e aperta alle relazioni con l'area mediterranea. Lo studio proposto in questo volume, partendo dai dati relativi ai materiali ceramici restituiti dalla stratigrafia archeologica dei settori indagati dal 2000 al 2012, testimonia i rapporti commerciali intercorsi fra il territorio servito dalla presenza del complesso catacombale, coincidente con quello dell'ecclesia carinensis citata da Gregorio Magno, e l'Africa romana e protobizantina.
Monitoraggio dell'attività biologica marina su provini ceramici: nuovi approcci metologici
2015
II deterioramento dei manufatti lapidei e ceramici sommersi è un processo che si sviluppa attraverso eventi fisici, chimici (abrasione, deposizione, ossidazione e riduzione ) e biologici attraverso la colonizzazione biologica da parte di microrganismi prima e di macrorganismi successivamente (Lopez-Arce et al. 2013, Aloise et al. 2013), in quanto i materiali forniscono un substrato di attacco per la loro crescita. In un recente progetto PRIN dal titolo "Approcci innovativi per lo studio sperimentale di manufatti ceramici “sommersi" sono stati valutati gli effetti delle diverse condizioni di giacitura dei reperti ceramici e del conseguente deterioramento, mediante uno studio multidisciplinar…
Influence of Mn site doping on electrical resistivity of polycrystalline La1-yAyMn1-xBxO3 (A=Ba, Sr; B=Cu, Cr, Co) Manganites
2008
We have the measured electrical resistivity of La1-yBayMn1-xCuxO3 (0.17?y?0.30; 0.04?x?0.10), La1-ySryMn1-xCrxO3 and La1-ySryMn1-xCoxO3 (0.270?y?0.294; 0.02?x?0.10) polycrystalline samples in the 25-325 K temperature range. The increase of Mn site doping concentration leads to an increase of the electrical resistivity of the samples and the appearance of a ?double-peak? structure in the electrical resistivity versus temperature graphs. The first peak represents the insulator-metal transition in vicinity of the paramagnetic-ferromagnetic transition (TC). We have found that the intensity of the second peak increases with an increase of concentration of Mn substituents, due to the hole scatter…
Synthesis and self-assembly of a PEGylated-graphene aerogel
2016
Abstract In the frame of this work, we present, for the first time, the synthesis and self-assembly of an aerogel built by graphene oxide-polyethylene glycol. The synthetic route involves at first the coupling of GO with an amino-terminated polyethylene glycol sample by carbodiimide in aqueous environment, and the subsequent conversion of the hydrogel achieved into an aerogel via freeze-drying. The 3D PEGylated graphene-based aerogel, characterized by spectroscopic, morphological, structural and mechanical analyses, displays an ultralight and highly porous (99.7%) network and possesses high mechanical properties together with a good biocompatibility.