Search results for "ceramic"

Room temperature synthesis of lanthanum phosphates with controlled nanotexture as host for Ln(III) through the Epoxide Route

2022

AbstractHerein, the Epoxide Route, a one-pot room temperature alkalinization method based on the reaction between a nucleophile and an epoxide, has been employed to synthesize LaPO4 in the form of a Rhabdophane phase. The intrinsic features of this synthetic approach allow the reaction to be followed by pH monitoring, making possible the identification of the different precipitation steps involved in the formation of the solid. Once demonstrated the effectiveness of this chemical methodology, the size and shape of the LaPO4 particles were controlled by varying the identity and proportion of the organic co-solvents employed to perform the reaction. By these means, crystalline particles with …

L'occupation humaine du Grand-Duché de Luxembourg à l'âge du Bronze Final : inventaire des sites et bilan de l'état de la documentation

2017

International audience

Caractérisation des céramiques à bioclastes de la Protohistoire dans l’ouest de la France.

2015

The study of the ceramics from the site of the Batterie Basse in the region of Manche, shows again that the presence of bioclasts in the clays of protohistoric ceramics is a very common phenomenon in Normandy unlike in Brittany, where in the current state of knowledge only one individual from the Iron Age has been described. These bioclasts, mostly fragments of bivalves, are non-plastic elements naturally present in the clays, either in the form of fossils, either in the form of contemporary shells, or are incorporated by the craftsmans after being pounded to modify the technical characteristics of the clays. The aim of this work is to awareness the archaeologists to this type of artefacts …

Shippers vs. freight forwarders: Do they differ in their port choice decisions? Evidence from the Spanish ceramic tile industry

2022

The present research aims to compare shippers’ and freight forwarders' port choice criteria in order to identify the main differences between these two decision-makers. Specifically, the research focuses on the port choice of the shippers belonging to the Spanish ceramic tile industry and the freight forwarders who manage their shipments. To do so, a mixed logit model is used with data obtained through a stated preference experiment. According to our results, shippers and freight forwarders differ only in the valuation of the cost attribute, with the latter being more cost-sensitive. Moreover, results indicate that freight forwarders are more conservative in their port choice decisions, as …

Ricerca sulla simulazione del funzionamento in regime vario di forni continui per la cottura di ceramiche e porcellane

2005

Fibre fragment distribution in a single-fibre composite tension test

2001

Abstract Single fibre fragmentation tests are performed for brittle fibres with Weibull strength distribution and different surface treatments. The fragmentation process is modelled and closed-form expressions for break spacing distribution are obtained. The model accounts for the effect of finite fibre length on the initial fragmentation as well as for break interaction on the advanced fragmentation stage. It is assumed that the exclusion zone due to fibre–matrix interface failure and stress recovery in the fibre is linearly dependent on the applied load. This assumption is validated experimentally. The derived theoretical average fragment length dependence on applied load is used to deter…

Bi-2212 and Y123 highly curved single-crystal-like objects: whiskers, bows and ring-like structures

2012

High-temperature superconducting objects of Bi2Sr2CaCu2O8 and Y Ba2Cu3O7 highly curved in the ab-plane, such as curved/kinked whiskers, bows and ring-like structures, were obtained within a solid?liquid?solid (SLS) grass-like growth mechanism. As-grown objects are crystals with three-dimensional epitaxy similar to conventional single crystals: they can be viewed as crystal parts ?cut? from a conventional rectangular crystal. Between our curved objects and conventional crystals, whiskers or thin films there are some differences in the superconducting properties induced only by the shape factors and no new physics is observed. Some details of the growth mechanism are discussed, emphasizing cu…

BODIPY atropisomer interconversion, face discrimination, and superstructure appending

2016

International audience; A strategy was developed to append sterically hindered apical pickets on both faces of the BODIPY platform to prevent stacking and aggregation. Ortho-substitution of both the meso-phenyl ring and the boron-bound catechol affords the right directionality to append pickets, achieve face discrimination, featuring two inter-convertible atropisomers, and is reminiscent of the picket-fence strategy in porphyrins.

Spectroscopic characterization of alkaline earth uranyl carbonates

2005

A series of alkaline uranyl carbonates, M[UO{sub 2}(CO{sub 3}){sub 3}].nH{sub 2}O (M=Mg{sub 2}, Ca{sub 2}, Sr{sub 2}, Ba{sub 2}, Na{sub 2}Ca, and CaMg) was synthesized and characterized by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after nitric acid digestion, X-ray powder diffraction (XRD), and thermal analysis (TGA/DTA). The molecular structure of these compounds was characterized by extended X-ray absorption fine-structure (EXAFS) spectroscopy and X-ray photoelectron spectroscopy (XPS). Crystalline Ba{sub 2}[UO{sub 2}(CO{sub 3}){sub 3}].6H{sub 2}O was obtained for the first time. The EXAFS analysis showed that this compound consists of …

Clinical Behavior of Ceramic, Hybrid and Composite Onlays. A Systematic Review and Meta-Analysis

2020

A systematic review and meta-analysis was performed to analyze the survival of onlay restorations in the posterior region, their clinical behavior according to the material used (ceramic reinforced with lithium disilicate, conventional feldspathic ceramic or reinforced with leucite; hybrid materials and composite), possible complications, and the factors influencing restoration success. The systematic review was based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, without publication date or language restrictions. An electronic search was made in the PubMed, Scopus, Embase, and Cochrane databases. After discarding duplicate publications and stu…