Preparation of Thin Sections of Porous Materials for Polarizing Microscope Investigation in Archaeometry

2017 ◽  
Vol 3 (2) ◽  
pp. 45-60
Author(s):  
Mehdi Razani ◽  
Feli Martinez Conejero ◽  
Mahin Mansori Isfahani ◽  
Hakimeh Afsharinezhad ◽  
◽  
...  
2010 ◽  
Vol 7 (2) ◽  
pp. 045-042
Author(s):  
Beata Klimek

The problem connected with the methodology of research on old binders remains unsolved. The reason of this situation raises from the impossibility of creating one formula according to which all old binders ally known. One might think that a simultaneous use of all the methods for research on binders coming from historical objects would guarantee complete information on the binders. At the same time the information would be helpful in restoration process, especially those of reconstruction would in the identifying of the causes of damages. A considerable difficulty with talking samples is an additional problem. This refers first of all to  plasters located below paintings, where the possibility of talking samples is very limited because of a possible damaging of the painting. It is especially do research which will provide maximum information, because after carrying out restoration works many marks may be impossible to remake. Therefore making a decision on the type of research one should find such information which will provide the line of further research. The introductory information may be collected through the observation of thin sections in transmitted light with a polarizing microscope. An analysis analogous to that which is done at the identification of rocks–petrography analysis.


1947 ◽  
Vol 84 (6) ◽  
pp. 354-359 ◽  
Author(s):  
J. W. Fowler ◽  
J. Shirley

During the investigation of certain water-soluble and porous materials it was necessary to produce thin sections showing their structure and crystal composition. Using water as a lubricant during the thinning of the sections the specimens tended to break up and essential constituents were lost through solution, while paraffin had a marked solvent action on the Canada balsam cement resulting in disintegration of the thin section and contamination by particles of carborundum.


Author(s):  
Frank Smithson

Phase-contrast methods in microscopy appear to have been developed mainly with the intention of applying them to biological subjects, and their application to the examination of mineral substances has received only slight attention. Thin sections of rocks viewed under a phase-contrast microscope have a fascinatingly strange appearance and it does not take long to realize that some features are shown up more clearly and others less clearly than when viewed under an ordinary or a polarizing microscope. A considerable amount of work may be necessary before it is possible to assess the value of the new instrument for petrological purposes or to interpret all the phenomena observed by its aid. Nevertheless, it seems fitting to set out the following short account as a contribution towards this knowledge.


2021 ◽  
pp. 1570-1586
Author(s):  
Maryam Al-Hassani ◽  
Salam Al-Dulaimi

The Yamama Formation was studied in three wells (Fh-1, Fh-2, and Fh-3) within Faihaa oil field, south Iraq. Thin sections were studied by using the polarizing microscope examination in order to determine microfossils and biozone. Thirty-five species of benthic foraminifera were recognized, including four index species. In addition,  twelve species of calcareous green algae were recognized, including  two index species. Other fossils that were recognized in Yamama Formation include Gastropoda, Bryozoa, Coral, Rudist, and Pelecypoda. Six biozones were observed, which are Charentia cuvillieri sp. (Range Zone of Berriasian age), Psudochryalidina infracretacea sp. (Range Zone of Berriasian age), Pseudocyclammina Lituus sp. (Range Zone of Valanginian age), Nezzazata Perforate sp.andChoffatella sp.(Assemblage Zoneof Berriasian-Valanginian age), Desycladales Green Algae- Cylindroporella sp. (Range Zone of Early Cretaceous- Berriasian age), and Desycladales Green Algae- Salpingoporella cf. circassa sp. (Range Zone of Valanginian age). According to these biozones, the age of Yamama Formation was distinguished to be the Berriasian-Valanginian.


1970 ◽  
Vol 38 (1) ◽  
pp. 103-105
Author(s):  
Hatice Çölgeçen ◽  
Ayse Kaplan ◽  
H Nurhan Büyükkartal

Leaves of Quercus cerris L. were collected from Zonguldak, Devrek and those of Q. ilex L. samples were collected from Zonguldak, Ere?li, Turkey. The leaf sections were subjected to histochemical analysis and brown-black stained calcium oxalate crystals were identified. The organic contents in the leaves were completely cleaned for polarizing microscope investigation. Calcium oxalate crystals were found to be druz and prismatic in Q. cerris and Q. ilex species. While druz crystals were localized in mesophyll, prismatic ones were localized around the leaf vessels. The amount of calcium oxalate crystals per mm2 was determined in permanent preparations.    


Author(s):  
J. R. Ruby

Parotid glands were obtained from five adult (four male and one female) armadillos (Dasypus novemcinctus) which were perfusion-fixed. The glands were located in a position similar to that of most mammals. They extended interiorly to the anterior portion of the submandibular gland.In the light microscope, it was noted that the acini were relatively small and stained strongly positive with the periodic acid-Schiff (PAS) and alcian blue techniques, confirming the earlier results of Shackleford (1). Based on these qualities and other structural criteria, these cells have been classified as seromucous (2). The duct system was well developed. There were numerous intercalated ducts and intralobular striated ducts. The striated duct cells contained large amounts of PAS-positive substance.Thin sections revealed that the acinar cells were pyramidal in shape and contained a basally placed, slightly flattened nucleus (Fig. 1). The rough endoplasmic reticulum was also at the base of the cell.


Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
J.R. Walton

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.


Author(s):  
E.J. Jenkins ◽  
D.S. Tucker ◽  
J.J. Hren

The size range of mineral and ceramic particles of one to a few microns is awkward to prepare for examination by TEM. Electrons can be transmitted through smaller particles directly and larger particles can be thinned by crushing and dispersion onto a substrate or by embedding in a film followed by ion milling. Attempts at dispersion onto a thin film substrate often result in particle aggregation by van der Waals attraction. In the present work we studied 1-10 μm diameter Al2O3 spheres which were transformed from the amprphous state to the stable α phase.After the appropriate heat treatment, the spherical powders were embedded in as high a density as practicable in a hard EPON, and then microtomed into thin sections. There are several advantages to this method. Obviously, this is a rapid and convenient means to study the microstructure of serial slices. EDS, ELS, and diffraction studies are also considerably more informative. Furthermore, confidence in sampling reliability is considerably enhanced. The major negative feature is some distortion of the microstructure inherent to the microtoming operation; however, this appears to have been surprisingly small. The details of the method and some typical results follow.


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