SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

Scanning Electron Microscopy of Fish Scales as an Adjunctive Aid in Speciation

1972 ◽  
Vol 30 ◽  
pp. 394-395
Author(s):  
Edward D. DeLamater ◽  
Walter R. Courtenay ◽  
Cecil Whitaker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lateral Line ◽  
Species Differences ◽  
Fish Scale ◽  
Fish Scales ◽  
Anterior Border ◽  
The University ◽  
Multiple Holes ◽  
Scanning Electron

Comparative scanning electron microscopy studies of fish scales of different orders, families, genera and species within genera have demonstrated differences which warrant elaboration. These differences in detail appear to be sufficient to act as “fingerprints”, at least, for family differences. To date, the lateral line scales have been primarily studied. These demonstrate differences in the lateral line canals; the pattern of ridging with or without secondary protuberances along the edges; the pattern of spines or their absence on the anterior border of the scales; the presence or absence of single or multiple holes on the ventral and dorsal sides of the lateral line canal covers. The distances between the ridges in the pattern appear likewise to be important.A statement of fish scale structure and a comparison of family and species differences will be presented.The authors wish to thank Dr. Donald Marzalek and Mr. Wallace Charm of the Marine and Atmospheric Laboratory of the University of Miami and Dr. Sheldon Moll and Dr. Richard Turnage of AMR for their exhaustive help in these preliminary studies.

Scattering of Electrons at High - Pressure and Restoration of Image Contrast in High Pressure Scanning Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 384-385
Author(s):  
J. S. Shah ◽  
R. Durkin ◽  
A. N. Farley
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Cross Sections ◽  
Single Scattering ◽  
Image Contrast ◽  
Experimental Scheme ◽  
Medium Resolution ◽  
Scattering Approximation ◽  
Scanning Electron

It is now possible to perform High Pressure Scanning Electron Microscopy (HPSEM) in the range 10 to 2000 Pa. Here the effect of scattering on resolution has been evaluated by calculating the profile of the beam in high pressure and assessing its effect on the image contrast . An experimental scheme is presented to show that the effect of the primary beam ionization is to reduce image contrast but this effect can be eliminated by a novel use of specimen current detection in the presence of an electric field. The mechanism of image enhancement is discussed in terms of collection of additional carriers generated by the emissive components.High Pressure SEM (HPSEM) instrumentation is establishing itself as commercially viable. There are now a number of manufacturers, such as JEOL, ABT, ESCAN, DEBEN RESEARCH, selling microscopes and accessories for HPSEM. This is because high pressure techniques have begun to yield high quality micrographs at medium resolution.To study the effect of scattering on the incident electron beam, its profile - in a high pressure environment - was evaluated by calculating the elastic and inelastic scattering cross sections for nitrogen in the energy range 5-25 keV. To assess the effect of the scattered beam on the image contrast, the modification of a sharp step contrast function due to scattering was calculated by single scattering approximation and experimentally confirmed for a 20kV accelerated beam.

Determination of cotton fiber maturity and linear density (fineness) by examination of fiber cross-sections. Part 2: A comparison optical and scanning electron microscopy

2014 ◽  
Vol 84 (18) ◽  
pp. 1939-1947 ◽  
Author(s):  
Geoffrey RS Naylor ◽  
Margaret Pate ◽  
Graham J Higgerson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Optical Microscopy ◽  
Cross Sections ◽  
Linear Density ◽  
Wall Area ◽  
Density Values ◽  
Fiber Maturity ◽  
Scanning Electron

Previous researchers established a set of reference cottons with known fiber maturity and linear density (fineness) values based on the analysis of a large number of individual transverse fiber cross-sections viewed under the optical microscope. Part 1 identified that the limited optical resolution of the captured images may be the source of a significant systematic error in the assigned values of cell wall area and hence fiber maturity and linear density values. In this paper the optical microscopy technique was implemented. Individual cross-sections were measured using this approach and also higher resolution and higher magnification images were obtained using scanning electron microscopy. It was found that the data obtained from optical microscopy were similar to the SEM data, with the perimeter being 2% smaller, the cell wall area being 6% larger and the maturity ratio values being 8% higher. It was concluded that the combined approach of utilizing SEM in conjunction with optical imaging is a useful approach for verifying and perhaps correcting the data obtained from optical imaging. Further the SEM images highlighted that the current experimental protocol does not adequately address the challenge of ensuring that the fibers are mounted normal to the plane of cutting the transverse cross-section. Modeling demonstrated that while maturity ratio values are relatively insensitive to this misalignment, measured cell wall area values and hence fiber linear density values will be overestimated. This may be the major source of error associated with the technique and warrants further attention in future studies.

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

Glass-Alumina Functionally Graded Materials Produced by Plasma Spraying

2007 ◽  
Vol 333 ◽  
pp. 227-230
Author(s):  
Valeria Cannillo ◽  
Luca Lusvarghi ◽  
Tiziano Manfredini ◽  
M. Montorsi ◽  
Cristina Siligardi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Plasma Spraying ◽  
Functionally Graded Materials ◽  
Cross Sections ◽  
Functionally Graded ◽  
Depth Sensing ◽  
Graded Materials ◽  
Set Up ◽  
Scanning Electron

The present work was focused on glass-alumina functionally graded materials. The samples, produced by plasma spraying, were built as multi-layered systems by depositing several layers of slightly different composition, since their alumina and glass content was progressively changed. After fabricating the graded materials, several, proper characterization techniques were set up to investigate the gradient in composition, microstructure and related performances. A particular attention was paid to the observation of the graded cross sections by scanning electron microscopy, which allowed to visualize directly the graded microstructural changes. The scanning electron microscopy (SEM) inspection was integrated with accurate mechanical measurements, such as systematic depth-sensing Vickers microindentation tests performed on the graded cross sections.

scholarly journals PROVENANCE OF PINDOS FORELAND FLYSCH DEPOSITS USING SCANNING ELECTRON MICROSCOPY AND MICROANALYSIS

2004 ◽  
Vol 36 (1) ◽  
pp. 607 ◽  
Author(s):  
I. Vakalas ◽  
G. Ananiadis ◽  
A. Zelilidis ◽  
N. Kontopoulos ◽  
B. Tsikouras
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Thin Sections ◽  
Source Areas ◽  
Probable Source ◽  
Pelagonian Zone ◽  
Source Materials ◽  
Scanning Electron

A number of polished thin sections from two cross sections within the Pindos foreland deposits were petrographically examined while microanalyses on certain minerals were carried out. Chemistry of these minerals is compared to analogous phases occurring in several formations in the neighbourhood of the studied areas which can stand as source areas. Our results reveal that the most probable source materials include the Pindos, Koziakas (and probably and Vourinos) ophiolite complexes, as well as metamorphic sequences of the Pelagonian Zone

Study of fossil bones by synchrotron radiation micro-spectroscopic techniques and scanning electron microscopy

2013 ◽  
Vol 21 (1) ◽  
pp. 149-160 ◽  
Author(s):  
I. M. Zougrou ◽  
M. Katsikini ◽  
F. Pinakidou ◽  
E. C. Paloura ◽  
L. Papadopoulou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Weight Ratio ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Osteocyte Lacunae ◽  
Fossil Bones ◽  
Bone Apatite ◽  
Scanning Electron

Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro-lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil-originating elements was studied using micro-X-ray fluorescence (µ-XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities,e.g.Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ-XRF varied significantly in metal-poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the FeK-edge X-ray absorption fine structure (XAFS) spectra. Finally, SrK-edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca1or Ca2unit-cell site occupation.

Study of Mechanical Degradation and Microstructural Characterization in a Ni-Based Superalloy Component of a Gas Turbine

2018 ◽  
Vol 941 ◽  
pp. 1248-1253
Author(s):  
Erika O. Avila-Davila ◽  
Victor M. Lopez-Hirata ◽  
Maribel L. Saucedo-Muñoz ◽  
Luis M. Palacios-Pineda ◽  
Ignacio Ramirez-Vargas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanical Behavior ◽  
Gas Turbine ◽  
Cross Sections ◽  
Microstructural Characterization ◽  
Operating Conditions ◽  
Critical Parameters ◽  
Ansys Software ◽  
Scanning Electron

The microstructural characterization of a blade made of Ni-based superalloy was carried out and discussed. The blade was removed from service, of a gas turbine, due to preventive maintenance. This component was studied on different cross sections according to the surface temperature obtained by ANSYS software. The cross sections were characterized by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and High Resolution Scanning Electron Microscopy (HR-SEM). It was determined that the maximum value of total deformation is 0.001717 mm, located in the surface upper section of the blade, which not correspond to the section with the highest value of temperature calculated with ANSYS software. These results were consistent with the rafted microstructure observed at the upper region of the blade. Microcavities close to the MC carbides with a size of about 40x10-6m were also observed. The mechanical behavior of the Ni-based superalloy was studied by Rockwell Hardness testing (RHT). So, morphological changes were identified in the occurrence of the strengthening precipitated, γ', according to the operating conditions: stress and temperature. The average radius of the γ' precipitated was obtained by computer image analysis using ImageJ software. No clear relationship was found between the hardness values obtained and the coarsened γ' precipitated. A bimodal occurrence of coarsened γ' particles was identified distributed through γ matrix by HR-SEM. Thus, this study was carried out with the purpose to identify the critical parameters that promote microstructural changes in the Ni-based superalloy and therefore affect the mechanical behavior in this turbine blade.

Development of Alginate Based Active Films Containing Turmeric Essential Oil

2020 ◽  
Vol 861 ◽  
pp. 378-382
Author(s):  
Sophoan Phal ◽  
Muhammad Rafiullah Khan ◽  
Pattarin Leelaphiwat ◽  
Vanee Chonhenchob
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Water Vapor ◽  
Essential Oil ◽  
Sem Analysis ◽  
Film Properties ◽  
Elongation At Break ◽  
Control Film ◽  
Scanning Electron

Sodium alginate based films containing turmeric oil (TEO) at different concentrations (1, 2 and 3%) were developed. The film with no TEO was used as control. Incorporation of TEO had the effects on the film properties. With increasing TEO concentrations, thickness, elongation at break, permeability of oxygen and water vapor of the films significantly (p ≤ 0.05) increased. Whereas moisture content, tensile strength and modulus of elasticity significantly (p ≤ 0.05) decreased. Scanning electron microscopy (SEM) analysis showed more numerous pores and rougher surface of the antifungal films than the control film.

scholarly journals What Is Considered a Variation of Biomechanical Parameters in Tensile Tests of Collagen-Rich Human Soft Tissues?—Critical Considerations Using the Human Cranial Dura Mater as a Representative Morpho-Mechanic Model

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 520
Author(s):  
Johann Zwirner ◽  
Mario Scholze ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Dura Mater ◽  
Soft Tissues ◽  
Tensile Tests ◽  
Interquartile Range ◽  
Tissue Structure ◽  
Mechanical Parameters ◽  
Scanning Electron

Background and Objectives: Profound knowledge on the load-dependent behavior of human soft tissues is required for the development of suitable replacements as well as for realistic computer simulations. Regarding the former, e.g., the anisotropy of a particular biological tissue has to be represented with site- and direction-dependent particular mechanical values. Contrary to this concept of consistent mechanical properties of a defined soft tissue, mechanical parameters of soft tissues scatter considerably when being determined in tensile tests. In spite of numerous measures taken to standardize the mechanical testing of soft tissues, several setup- and tissue-related factors remain to influence the mechanical parameters of human soft tissues to a yet unknown extent. It is to date unclear if measurement extremes should be considered a variation or whether these data have to be deemed incorrect measurement outliers. This given study aimed to determine mechanical parameters of the human cranial dura mater as a model for human soft tissues using a highly standardized protocol and based on this, critically evaluate the definition for the term mechanical “variation” of human soft tissue. Materials and Methods: A total of 124 human dura mater samples with an age range of 3 weeks to 94 years were uniformly retrieved, osmotically adapted and mechanically tested using customized 3D-printed equipment in a quasi-static tensile testing setup. Scanning electron microscopy of 14 samples was conducted to relate the mechanical parameters to morphological features of the dura mater. Results: The here obtained mechanical parameters were scattered (elastic modulus = 46.06 MPa, interquartile range = 33.78 MPa; ultimate tensile strength = 5.56 MPa, interquartile range = 4.09 MPa; strain at maximum force = 16.58%, interquartile range = 4.81%). Scanning electron microscopy revealed a multi-layered nature of the dura mater with varying fiber directions between its outer and inner surface. Conclusions: It is concluded that mechanical parameters of soft tissues such as human dura mater are highly variable even if a highly standardized testing setup is involved. The tissue structure and composition appeared to be the main contributor to the scatter of the mechanical parameters. In consequence, mechanical variation of soft tissues can be defined as the extremes of a biomechanical parameter due to an uncontrollable change in tissue structure and/or the respective testing setup.

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