Search results for "Ceramic"

Converting p-terphenyl into a novel organo-catalyst for LED-driven energy and electron transfer photoreactions in water.

2021

p-Terphenyl is a potent photoredox catalyst under UV-irradiation. Aiming for more sustainable reaction conditions, we added two sulfonate groups to this key structure to achieve water solubility and incorporated an SO2-bridge thereby shifting the absorption spectrum towards the visible. The resulting photocatalyst shows unexpected triplet reactivity in several test reactions.

Mesoporous aluminum phosphite

2009

Abstract High surface area pure mesoporous aluminum-phosphorus oxide-based derivatives have been synthesized through an S+I− surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from aluminum atrane complexes and phosphoric and/or phosphorous acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from mesoporous aluminum phosphate (ALPO) up to total incorporation of phosphite entities (mesoporous aluminum phosphite), which results in a gradual evolution of the acid…

A new method for fluoride determination by using fluorophores and dyes anchored onto MCM-41Electronic supplementary information (ESI) available: IR s…

2002

A new colourimetric and fluorimetric method for fluoride determination in aqueous samples based on the specific reaction between fluoride and silica has been developed and applied on real samples.

Oxidative transformation of aryls using molybdenum pentachloride.

2012

Molybdenum pentachloride combines a strong Lewis acid character with an unusually high oxidation potential creating a powerful reagent for oxidative transformations. Since the oxidative coupling reaction of aryls is induced at an extraordinarily high reaction rate, a variety of labile groups, e.g. iodo, tert-alkyl, etc., are tolerated on the aromatic core. Furthermore, the co-formed molybdenum salts can either be exploited for template effects to obtain uncommon geometries in a preferred manner, or redox-play starts after aqueous workup. Therefore MoCl(5) represents a unique and easily available reagent.

Synthesis of new molybdenum–tungsten, vanadium–tungsten and vanadium–molybdenum–tungsten oxynitrides from freeze-dried precursors

2004

Abstract Interstitial molybdenum–tungsten, vanadium–tungsten and vanadium–molybdenum–tungsten oxynitrides in the solid solution series Mo1−zWz(OxNy) and V1−zWz(OxNy) (z=0, 0.2, 0.4, 0.5, 0.6, 0.8, 1), and V1−u−zMouWz(OxNy) (u, z=0.2, 0.33, 0.4, 0.6; u+z

L’area ad Est dell’ipogeo L. Il saggio D. Le olle. I sostegni. Gli oggetti vari.

2007

The essay concerns the results of the archaeological excavation carried out in the area East of the s.c. "hypogeum L" in the Early Christian cemetery of Agrigentum in the year 1999; it contains, also, the catalogue of the Medieval coarse and cooking wares (ollae) found in the area, and the different types of supports used in the ceramic workshop established in the Late Antique cemetery during the Middle Ages.

Archaeometric characterization of late Archaic ceramic from Erice (Sicily) aimed to provenance determination

2019

A set of 20 ceramic samples was autoptically selected from the numerous findings recovered from the stratigraphic excavations of the late Archaic city walls of Erice (western Sicily), in order to be analyzed with archaeometric techniques for provenance determination. The excavations were recently carried out as part of a research project funded by the Freie Universiat Berlin and the Fritz Thyssen Foundation. Specifically, the ceramic material consists of tableware with a painted geometric decoration of presumed local/regional production, as well as apparently imported black-glazed pottery. Both the categories can be traced back to a chronological period between the second half/last quarter …

Les dynamiques de l’Islamisation en Méditerranée centrale et en Sicile: nouvelles propositions et découvertes réecentes. Le diamiche dell’islamizzazi…

2014

Selinunte (Sicily) and its productive context: the clayey raw materials applied in a long-lived ceramic production (seventh to third century BCE)

2016

The westernmost of the Greek-Sicilian towns, Selinunte, founded in western Sicily during the second half of the seventh century BCE, gives amazing evidences of a historic activity of ceramic production (seventh to third century BCE). The present study aims to identify the raw materials available in the vicinity of the archaeological site of Selinunte, which were possibly used by the ancient potters, and to characterise them by means of petrographic and chemical techniques. A sampling campaign of clays and sands for tempering was undertaken in the archaeological site and the adjacent area. Moreover, locally produced archaeological bricks and tiles were considered helpful for comparison regar…

Early Bronze Age painted wares from Tell el-'Abd, Syria: A compositional and technological study

2018

Abstract The ‘Euphrates Monochrome Painted Ware’ (henceforth EMPW) is a ceramic style attested in the Middle Euphrates region in northern Syria at the beginning of the Early Bronze Age, ca. 2900–2700 BCE. This style is not an isolated phenomenon; rather, it must be understood in the context of a general, albeit short-lived, re-introduction of painted ceramics into local assemblages of Greater Mesopotamia. In the present study, we investigate the technology and provenance of the painted pottery from Tell el-'Abd (North Syria) and its relation to contemporary ceramics retrieved at this site. We apply a combination of macroscopic observations, ceramic petrography, and micro X-ray diffraction (…