Deux assiettes, Paul et Joseph Hannong : une analyse technologique»

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Published in "Archaeometry: doi: 10.1111/j.1475-4754.2009.00500.x, 2009" which should be cited to refer to this work. PAUL-LOUIS CYFFLÉ’S (1724–1806) TERRE DE LORRAINE: A TECHNOLOGICAL STUDY*

Fragments of four Terre de Lorraine biscuit figurines were subjected to porosity analysis, X-ray fluorescence analysis, X-ray diffraction analysis, backscattered-electron image analysis—coupled with energy dispersive spectrometry—and electron backscatter diffraction analysis to determine the porosity, bulk, major, minor and trace element compositions, and the composition and the proportion of their constituent phases. Cyfflé’s Terre de Lorraine wares embrace two distinct types of paste, a calcareous and an aluminous–siliceous one. Both are porous (9–25 % water adsorption). The former consists of a mixture of different proportions of ground quartz or calcined flint, ground Pb-bearing glass and calcium carbonate with a refractory clay. The firing temperature was between 950 and 1050°C. For the latter, Cyfflé mixed ground pure amorphous SiO 2, ground quartz or calcined flint, ground porcelain, ground Na–Ca-glass and coarse-grained kaolinite with a fine-grained kaolinitic clay. The figurines were fired below 1000°C. The result was a porous, hard paste porcelain-like material. Cyfflé’s recipes for both pastes can be calculated from the chemical and the modal analyses

Distribution of benthic foraminiferal assemblages in the transitional environment of the Djerba lagoon (Tunisia)

The eastern edge of the Djerba Island represents an important tourist pole. However, studies describing the environmental processes affecting this Island are scarce. Although never studied before, the peculiar Djerba lagoon is well known by the local population and by tourists. In July 2014, surface sediment and seawater samples were collected in this lagoon to measure grain size, organic matter content and living foraminiferal assemblages to describe environmental conditions. Seawater samples were also collected and the concentration of 17 chemical elements were measured by ICP-OES. The results show that a salinity gradient along the studied transect clearly impacts seagrass distribution, creating different environmental conditions inside the Djerba lagoon. Biotic and abiotic parameters reflect a transitional environment from hypersaline to normal marine conditions. Living benthic foraminifera show an adaptation to changing conditions within the different parts of the lagoon. In particular, the presence of Ammonia spp. and Haynesina depressula correlates with hypersaline waters, whilst Brizalina striatula characterizes the parts of the lagoon colonized by seagrass. Epifaunal species, such as Rosalina vilardeboana and Amphistegina spp. colonize hard substrata present at the transition between the lagoon and the open sea

Impact of industrial phosphate waste discharge on the marine environment in the Gulf of Gabes (Tunisia)

The marine environment in the Gulf of Gabes (southern Tunisia) is severely impacted by phosphate industries. Nowadays, three localities, Sfax, Skhira and Gabes produce phosphoric acid along the coasts of this Gulf and generate a large amount of phosphogypsum as a waste product. The Gabes phosphate industry is the major cause of pollution in the Gulf because most of the waste is directly discharged into the sea without preliminary treatment. This study investigates the marine environment in the proximity of the phosphate industries of Gabes and the coastal marine environment on the eastern coast of Djerba, without phosphate industry. This site can be considered as "pristine" and enables a direct comparison between polluted and “clean” adjacent areas. Phosphorous, by sequential extractions (SEDEX), Rock-Eval, C, H, N elemental analysis, and stable carbon isotope composition of sedimentary organic matter, X-ray diffraction (qualitative and quantitative analysis) were measured on sediments. Temperature, pH and dissolved oxygen were measured on the water close to the sea floor of each station to estimate environmental conditions. These analyses are coupled with video surveys of the sea floor. This study reveals clear differentiations in pollution and eutrophication in the investigated areas

Quantitative comparison of 3D pore space properties with magnetic pore fabrics—testing the ability of magnetic methods to predict pore fabrics in rocks

Abstract Pore fabrics characterize the anisotropy of pore space in rocks and influence the direction of fluid flow. This is important in reservoir characterization, and petroleum and geothermal energy exploitation. X‐ray computed micro‐tomography (XRCT) is commonly used to analyze pore fabrics, but limited by the micron‐scale resolution for representative 1‐inch rock cores. The magnetic pore fabric (MPF) method has been proposed to capture pores down to 10 nm. Although empirical relationships between MPF and pore space properties or permeability anisotropy are available, their application is compromised by large variability. This study integrates He pycnometry and XRCT‐derived pore space models with MPFs, and provides a quantitative comparison for calcarenite (∼50 vol% porosity and complex pore structure), and molasse sandstone (10%–30% porosity and relatively homogeneous pore fabrics). The preferred orientation of pores obtained from XRCT is described by a total shape ellipsoid, calculated by summing the second‐order tensors reflecting the best‐fit ellipsoids of individual pores. This ellipsoid is then compared to the MPF magnitude ellipsoid in terms of fabric orientation, degree and shape of anisotropy. The MPF and total shape ellipsoids are generally coaxial. The MPF has a smaller anisotropy degree than the total shape ellipsoid, and their relationship depends on the ferrofluid properties. The anisotropy shapes show large variability. Nevertheless, the good agreement of principal directions in most samples makes MPFs a valuable and efficient complementary tool to analyze a large number of samples, in combination with XRCT on selected samples, for a field‐scale pore space characterization

Passive sampler technique Sigma-2 with automated microscopic real colour image processing for particle measurements in the size range from 2.5-80 mu m

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