Thin-section analysis

ABSTRACT The aim of this study was to test portable infrared spectroscopy for non-destructive analysis of ancient construction mortar. Mortar samples from the House of the Vestals, in Pompeii, Italy, were initially examined with traditional analytical techniques, including X-ray fluorescence, X-ray diffraction and thin section analysis. These techniques were used to establish mineralogical and chemical profiles of the samples and to verify the results of experimental field methods. Results showed the lime-based binder was composed of calcite, and the volcanic sand aggregate contained clinopyroxene, plagioclase, sanidine and olivine crystals. 

For lateritic profiles, routine thin-section analysis can readily be achieved on those materials that represent the lower degrees of alteration... 

Thin-section analysis is an important (though destructive) tool. The void space is filled with epoxy or an equivalent compound, and the sample is sectioned and viewed by microscopy. The main advantage is the excellent resolution of detailed pore structure. However, sample preparation and image analysis are labor intensive. Additionally, three-dimensional structure can be obtained only by reconstruction from consecutive thin slices. 

Changes in the skeletal composition of sediments throughout the Ordovician of the East Baltic have been documented in considerable detail by thin section analysis. 

Depth of carbonation An average of 15 mm carbonation depth was determined from thin section analysis and this agreed well with the observed concrete spalling. Spraying of an indicator solution (phenolphthalein) on drilled powder can overestimate the real carbonation depth (Gabriel, 1996). 

Nevertheless, the location of minerals is of greatest importance. Scanning electron microscopy (SEM) and thin-section analysis are additional tools that are useful in identifying locations of quartz, clays, feldspars, carbonates, and other minerals. These are all factors considered in acid treatment design. Expertise is available through the major service companies, who should be contacted to help in treatment development. Input from company geologists should also be sought. 

The use of thin section analysis and fluorescent microscopy for the study of sedimentary oil-bearing rocks is described in the paper by Gather et al. 

This plastic deformation is localised around the crack tip and is present in all stressed engineering materials at normal temperatures. The shape and size of this plastic zone can be calculated using Westergaards analysis. The plastic zone has a characteristic butterfly shape (Fig. 8.83). There are two sizes of plastic zone. One is associated with plane stress conditions, e.g. thin sections of materials, and the other with plane strain conditions in thick sections-this zone is smaller than found under plane stress. 

Pore shape is a characteristic of pore geometry, which is important for fluid flow and especially multi-phase flow. It can be studied by analyzing three-dimensional images of the pore space [2, 3]. Also, long time diffusion coefficient measurements on rocks have been used to argue that the shapes of pores in many rocks are sheetlike and tube-like [16]. It has been shown in a recent study [57] that a combination of DDIF, mercury intrusion porosimetry and a simple analysis of two-dimensional thin-section images provides a characterization of pore shape (described below) from just the geometric properties. 

TXRF is most applicable to liquid samples, but success has also been achieved with direct analysis of some solids, e.g. very thin sections of organic tissue and polymer film. Alternatively, small amounts of solid material can be analysed by TXRF after acid digestion. 

The thickness of the ordered crystalline regions, termed crystallite or lamellar thickness (Lc), is an important parameter for correlations with thermodynamic and physical properties. Lc and the distribution of lamellar thicknesses can be determined by different experimental methods, including thin-section TEM mentioned earlier, atomic force microscopy, small-angle X-ray scattering and analysis of the LAM in Raman spectroscopy. 

For imaging MS analysis, animals were sacrificed, and the extirpated brains were immediately frozen in powdered dry ice and stored at -80°C until needed. Briefly, fresh-frozen tissues were sliced into 5-pm-thin sections and mounted... 

Polished thin sections were made in the absence of water to prevent dissolution of soluble phases. Mineral composition was determined using a combination of X-ray diffraction, electron microprobe analysis, and scanning electron microscopy with... 

Stoops G, Vepraskas MJ. Guidelines for Analysis and Description of Soil and Regolith Thin Sections. Madison, WI Soil Science Society of America 2003. 

Transmission electron microscopy pictures were taken using a JE0L 100 CX microscope. For some samples lateral micro-analysis of thin sections of zeolite was carried out using a HB-5 VG microscope equipped with EDX accessory at IFP (11). 

Analytical electron microscopy has been shown to be an effective technique for the chemical analysis of catalyst particles. In some cases AEM may be the only technique to provide chemical profiles across small particles. Analysis of thin sections of... 

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