Digital Commons Network^™

Applications Of Transmission Electron Microscopy To Coal, C. A. Wert, K. C. Hsieh, Mike Buckentin, B. H. Tseng

Scanning Microscopy

Coal consists of a hydrocarbon matrix in which minerals are embedded. The hydrocarbon matter also contains impurities distributed as individual atoms. Thus, coal has phases similar to those in metallic or ceramic alloy systems; a matrix, included precipitates and atoms distributed individually in solid solution. Consequently, techniques of electron microscopy developed to examine metallic and ceramic alloy systems are directly applicable to coal. We report application of microanalytical techniques of electron microscopy to coal using examples of measurements for several coals. Identification and characterization of clays and sulfides is described. Use of x-ray emission spectroscopy for organic element measurement is …

The Bulk Specimen X-Ray Microanalysis Of Freeze-Fractured, Freeze-Dried Tissues In Gerontological Research, I. Zs.-Nagy

Scanning Microscopy

The rationale for choosing the freeze-fracture freeze-drying (FFFD) method of biological bulk specimen preparation as well as the theoretical and practical problems of this method are treated. FFFD specimens are suitable for quantitative X-ray microanalysis of biologically relevant elements. Although the spatial resolution of this analytical technique is low, the application of properly selected bulk standard crystals as well as the measurement of the intracellular water and dry mass content by means of another method developed in the same laboratory, allow us to obtain useful information about the age-dependent changes of ionic composition in the main intracellular compartments. The paper …

Response Of Mouse Lung Air-Blood Barrier To X-Irradiation: Ultrastructural And Stereological Analysis, L. De Saint-Georges, U. Van Gorp, J. R. Maisin

Scanning Microscopy

Male mice of the Balb/c strain were exposed, at an age of three months, to a single dose of 10 or 20 Gy on the right hemithorax. At 3, 4, 6, 9 and 12 months after exposure, lungs were processed for electron microscopy following a standardized procedure in order to allow stereological analysis. By this method, the arithmetical mean thickness and, the air-blood barrier mean thickness in the lung parenchyma was shown to increase quickly with time by oedemization and fibrinization of the septal space. The ratio endothelium/epithelium surfaces (Sr/SF) gradually decreased by reduction of both surfaces but this was …

Impurity Lattice And Sublattice Location By Electron Channeling, S. J. Pennycook

Scanning Microscopy

A new formulation is presented for the use of crystallographic orientation effects in electron scattering to determine impurity lattice location. The development of electron channeling techniques is reviewed and compared to high energy ion channeling and to the Borrmann effect in x-ray diffraction. The advantages of axial over planar geometry are discussed. Delocalization effects are more serious for quantitative analysis than have generally been believed. The new formulation applies to any crystal lattice and quantitatively includes delocalization effects via c-factors, which have been experimentally determined for diamond structure semiconductors. For sublattice site location this formulation removes the two major approximations …

Electron Beam Testing Of Passivated Devices Via Capacitive Coupling Voltage Contrast, W. Reiners, K. D. Herrman, E. Kubalek

Scanning Microscopy

By fundamental experiments and theoretical treatments a detailed understanding of the capacitive coupling voltage contrast {CCVC) has been gained, demonstrating that this technique is, in principle, applicable to a non-destructive testing of passivated integrated circuits (IC) by means of electron beams. In fact, however, several problems have to be eliminated in order to introduce this testing technique into a production line procedure.

In a first step, preconditions have to be met. These are a primary electron (PE) energy where the electron yield is greater than one and a sufficiently low extraction field above the IC. Secondly, as CCVC vanishes within …

Elemental Levels In Mast Cell Granules Differ In Sections From Normal And Diabetic Rats: An X-Ray Microanalysis Study, Marion D. Kendall

Scanning Microscopy

Mast cells around the thymus of rats stain red with alcian blue and safranin indicating that the mast cells are probably of the peritoneal (connective tissue) type. After the onset of streptozotocin induced diabetes some cells contain both red and blue granules and blue staining cells may appear.

X-ray microanalysis of frozen freeze-dried sections from diabetic male CSE Wistar rats showed electron dense granules to have similar amounts of S to normal rat mast cell granules but reduced levels of Na, Mg, P, Cl and K. Two cells also had electron lucent granules with very high levels of Na, Cl, …

Developments In Voltage Contrast, P. Girard

Scanning Microscopy

The aim of this paper is to give a review of the main steps that have led to voltage contrast equipment available to day for integrated circuit testing.

The main parameters related to quantitative voltage evaluations are discussed in the case of measurements on integrated circuits metal stripes as well as on buried lines. They concern the reduction of the local field effects, the voltage resolution improvements on the energy analysers, and the time resolution. Results concerning the E-beam perturbation of MOS circuits are reported. Due to the test conditions and the presence of additional elements inside the microscope column …

Scanning Electron Microscopy, X-Ray Microanalysis And Immunohistochemistry On Worn Soft Contact Lenses, Piera Versura, M. C. Maltarello, Godfried M. Roomans, R. Caramazza, R. Laschi

Scanning Microscopy

The deposits accumulated on the surfaces of soft contact lenses are a cause of problems for the wearer of these lenses, as the deposits are never completely removed by the available washing solutions. Therefore it appears of interest to investigate the composition of these deposits.

In this paper we review the major findings in the literature and, in addition, present our personal experience.

We have studied new, continuously and daily worn soft contact lenses by scanning electron microscopy (SEM), X-ray microanalysis and immunohistochemistry. We have carefully evaluated preparative methods, and we can conclude that SEM and X-ray microanalysis are best …

Application Of Backscattered Electron Imaging And Lectin-Gold Cytochemistry To Visualize The Distribution Of Glycoconjugates In A Basal Lamina, Antonio Nanci, Sylvia Zalzal, Charles E. Smith

Scanning Microscopy

Basement membranes generally appear in transmission electron microscopy as thin, cross-sectioned profiles. Face-views are difficult to obtain particularly when their contours are curved or undulated. Such preparations are suited for the study of the distribution of basement membrane constituents through thickness but are limited for examining their spatial distribution. Scanning electron microscopy offers the potential of visualizing surface views. We have applied this approach to examining the three-dimensional distribution of glycoconjugates in a basement membrane. Large, face-views of the basal lamina related to maturation ameloblasts in the region where enamel of the rat incisor is EDTA soluble were exposed. Glycoconjugates …

Advanced Scanning Electron Microscopy Methods And Applications To Integrated Circuit Failure Analysis, E. I. Cole Jr., C. R. Bagnell Jr., B. G. Davies, A. M. Neacsu, W. V. Oxford, R. H. Propst

Scanning Microscopy

Semiconductor device failure analysis using the scanning electron microscope (SEM) has become a standard component of integrated circuit fabrication. Improvements in SEM capabilities and in digital imaging and processing have advanced standard acquisition modes and have promoted new failure analysis methods. The physical basis of various data acquisition modes, both standard and new, and their implementation on a computer controlled SEM image acquisition/processing system are discussed, emphasizing the advantages of each method. Design considerations for an integrated, online failure analysis system are also described. Recent developments in the integration of the information provided by electron beam analysis, conventional integrated circuit …

X-Ray Microanalysis Of Dentin: A Review, E. Hals, A. B. Tveit, B. Tøtdal

Scanning Microscopy

The aim of this review was to present a condensed summary of the literature on X-ray microanalysis of dentin, including both energy-dispersive (EDS) and wavelength-dispersive (WDS) analysis. Estimations of concentrations by XMA of dentin should be regarded as semiquantitative values. The Ca level in rat odontoblasts was elevated in the secreting end of the cell body. In predentin Ca accumulated at a concentration of 2% that of mineralized dentin. In coronal dentin the peritubular areas were hypermineralized (Ca, P, Mg). Primary caries lesions showed a decrease of Ca, P, Mg and Cl, and usually an increase of S and Zn. …

Adult Phyllostomid (Bat) Enamel By Scanning Electron Microscopy - With A Note On Dermopteran Enamel, K. S. Lester, S. J. Hand, F. Vincent

Scanning Microscopy

This study assesses the enamel of five phyllostomids of differing feeding habits; only one example of the microchiropteran super-family Phyllostomoidae having previously been studied by SEM. A dermopteran was also examined to ascertain whether the enamel might reveal insectivore, chiropteran or primate characteristics.

The five phyllostomids were found to display the additional crystallite discontinuity feature (minor boundary plane or seam) which is a major characteristic of all the bats we have so far examined with the exception of two megachiropterans. The enamel of the four fruit and nectar feeders (Phyllostomus, Carollia, Glossophaga and Artibeus) is essentially similar and different to …

Cleaning Procedures For Small Dental Instruments Prior To Sterilization, K. S. Lester, P. Mitchell

Scanning Microscopy

Observations were made in an institutional setting on the quality of cleaning of dental burs. Assessments were made by scanning electron microscopy of surface contamination and change to the surface quality of burs before and after use, and as a result of different cleaning procedures.

The most significant finding was the corrosive action on carbon steel burs of a phosphoric acid based cleaning solution in routine use at the time. We show by comparison the effectiveness and non-corrosive nature of an alternative detergent based on sulfamic acid, and propose a suitable cleaning routine.

Two other findings are presented: new burs …

The Emission Microscope: A Valuable Tool For Investigating The Fundamentals Of The Scanning Electron Microscope, Franz Hasselbach

Scanning Microscopy

In scanning microscopy in transmission (STEM) and reflection (SEM) the spreading of the spatial distributions of the forward-and backscattered electrons, respectively, deteriorates contrast and resolution. We therefore investigate this spreading by measuring quantitatively the corresponding distributions of secondaries released by these reemerging electrons. In order to carry out this experiment we visualize these distributions by using the surface of the specimen as the source of an emission microscope.

The spreading of transmitted beams of 19.5 keV in thin films of Al and Ge 0 .2-2 μm in thickness is reported here as well as the spatial distributions of secondaries released …

Electron Energy Loss Spectroscopic Imaging In Biology, G. T. Simon, Y. M. Heng

Scanning Microscopy

One of the goals in biology is to relate the ultrastructure with the movement of elements to under stand better physiological and pathophysiological mechanisms. Electron energy loss spectroscopy (EELS) imaging, which was developed in the last decade, appears to be an ideal technique to make such correlation.

EELS takes advantage of the energy distribution of transmitted electrons which interacted with the specimen. All these electrons are collected and can be displayed as an energy loss spectrum for analytical purposes. Images can be produced from selected regions from the energy distribution allowing the mapping of specific elements. The main advantage of …

An Overview Of Platelet Structural Physiology, J. G. White

Scanning Microscopy

Marion Barnhart and her colleagues used light, phase contrast and scanning electron microscopy to provide a clear picture of platelet surface changes developing in response to aggregating agents. This review, in honor of Marion and her work, has sought to expand the horizon provided through study of surface alterations by peeling back the membrane of the platelet to reveal the dynamic world within. A cytoskeleton consisting of a circumferential microtubule and submembrane actin filaments supports the discoid shape of the resting cell. Following exposure to aggregating agents in suspension, to foreign surfaces or denuded blood vessels and to fibrin strands …

Scanning Electron Microscopy Of Oral Mucosa In Vivo And In Vitro: A Review, Kristina Arvidson, Roland C. Grafström, Anders Pemer

Scanning Microscopy

The oral mucosa is classified by function into lining, masticatory and specialized oral mucosa, with regional structural adaptation. In this review, the surface structures of the human oral mucosa have been studied in the scanning electron microscope (SEM). Regional variations in regard to keratinization, cell arrangements and microplications with related specific structures observed in SEM are described and correlated with the appearance of similar areas observed in the light microscope. Furthermore, human oral tissue and cell cultures have also been studied. These systems offer usable and complementary models for performing similar studies in vitro under controlled experimental conditions. We now …

Age Dependent Dehydration Of Postmitotic Cells As Measured By X-Ray Microanalysis Of Bulk Specimens, György Lustyik, Imre Zs.-Nagy

Scanning Microscopy

In this paper we give a brief outline of our bulk specimen technique developed to measure intracellular water concentration in frozen-hydrated biological specimens by means of energy dispersive X-ray microanalysis. Fractured surface of the deep-frozen tissue samples is analyzed in an electron microscope (a specimen area of 15x11.5 𝝁m is scanned) using 20 kV accelerating voltage and 1-5 pA effective beam current (measured in the specimen). Strong electric charging, which is the main problem associated with the low temperature X-ray microanalysis of frozen-hydrated specimens, is reduced by choosing optimum temperature range for the measurements (170-185 K) and by etching a …

Tandem Scanning Reflected Light Microscopy: Applications In Clinical Dental Research, Timothy F. Watson, Alan Boyde

Scanning Microscopy

The Tandem Scanning Reflected Light Microscope (TSRLM) enables the investigation of microscopic structures both at and deep to the surface of intact objects. The present paper reviews studies undertaken to determine whether the TSRLM would be usable and useful in the investigation of natural and restorative dental materials in vitro and in vivo.

It was found that the TSRLM could be used to study normal and diseased dental tissues and the new materials which are used to replace lost substance. More importantly, it could be used to characterize the interface between tooth and optically translucent materials in bulk samples, giving …

Developmental Angiogenesis: Quail Embryonic Vasculature, T. J. Poole, J. D. Coffin

Scanning Microscopy

We have examined the segregation and early morphogenesis of the embryonic vasculature by using a monoclonal antibody for immunofluorescence and by scanning electron microscopy. This antibody labels the presumptive endothelial eel ls (PECs) as they segregate from mesoderm. Similar embryos prepared for SEM revealed finer details of how these segregated cells interact to form the rudiments of the major blood vessels. Here we concentrate on the development of the dorsal aortae and the posterior cardinal veins. The dorsal aortae form from single PECs which segregate from the lateral mesoderm and aggregate into a loose cord ventral to the somites. These …

Cell Rearrangement And Directional Migration In Pronephric Duct Development, T. J. Poole

Scanning Microscopy

The morphology of the directed migration of the pronephric duct rudiment of three vertebrates, the salamander, chick and sturgeon, has been examined by scanning electron microscopy. Of particular interest in this paper are the morphology of the duct tip, the role of cell rearrangement, and the relation of duct extension to somite segmentation. The duct rudiments of all three species have motile cell processes (lamellipodia and filopodia) largely confined to their posterior tips. The salamander and sturgeon embryos extend their duct rudiments by extensive cell rearrangements. A short, wide rudiment is elongated to form a long, thin one. The chick …

Ex Vivo Platelet Deposition On Fibronectin-Preadsorbed Surfaces, William E. Collins, Deane F. Mosher, Anil R. Diwan, Kedar D. Murthy, Scott R. Simmons, Ralph M. Albrecht, Stuart L. Cooper

Scanning Microscopy

Temporal platelet deposition profiles of canine plasma fibronectin (CPFN) adsorbed to different polymers ex vivo and the in vitro characteristics of CPFN adsorption were studied in an attempt to correlate the two. The maximum platelet deposition (𝚪_plt^max) obtained at a protein preadsorption time of 30 min was greater than that obtained using an adsorption time of 120 min for all surfaces studied. At 30 min of preadsorption, 𝚪_plt^max was 520, 560 and 1230 platelets/1000 μm² on Biomer, polyethylene (PE) and oxidized PE (OXPE), respectively. In contrast, the platelet deposition at 120 min. of fibronectin …

Scanning Electron Microscopy - Electron Beam Induced Current And Deep Level Transient Spectroscopy Studies Of Gaas(In) Layers Grown By Molecular Beam Epitaxy, Y. J. Huang, Dimitris E. Ioannou, A. Iliadis

Scanning Microscopy

Electrically active defects in indium-doped (0.6%) GaAs layers grown by Molecular Beam Epitaxy (MBE) on Si-doped (≈1x10¹⁸ cm^-3) GaAs substrates have been studied by the combination of two techniques: Scanning Electron Microscope - Electron Beam Induced Current (SEM-EBIC) technique, and Deep Level Transient Spectroscopy (DLTS). The epilayers studied were three microns thick. No electrically active defects were revealed by the EBIC micrographs in the top one micron of the epilayers, whereas a large number of non-propagating misfit dislocations were observed at the epilayer/substrate interface. DLTS measurements made in the dislocation free top region of the epilayer showed …

Preliminary Observations On The Effects In Vivo And In Vitro Of Low Dose Laser On The Epithelia Of The Bladder, Trachea And Tongue Of The Mouse, Y. C. Mok, K. M. Pang, C. Y. W. Au, D. T. Yew

Scanning Microscopy

The effects of low dose CW laser were studied by in vivo and in vitro systems. The experimental tissues that were used included bladders, tracheas and tongues as experimental tissues. Buddings (round surface projections) from the transitional epithelium of bladder were frequently observed 3 days after laser treatment in both in vivo and in vitro systems. The trachea and tongue were less affected. In both the in vivo and in vitro systems, some epithelial cells of the trachea showed decreased microvilli and cilia 3 days after treatment whereas the epithelial cells of the tongue revealed no response to laser treatment …

Scanning Microscopic Observations On Dental Caries, Sheila J. Jones, Alan Boyde

Scanning Microscopy

This paper presents findings made using special techniques of imaging and/or of specimen preparation to investigate the changes in tooth structure which occur in caries. We have studied both coronal and root caries in enamel, dentine and cementum using scanning electron and confocal scanning optical microscopy.

In preparation for backscattered electron (BSE) imaging in the SEM, teeth were stored in 70% ethanol until further dehydration in ethanol and embedding in polymethylmethacrylate (PMMA). Longitudinally cut surfaces were diamond polished and coated with carbon or silver before BSE imaging. Important changes in the distribution of densities in both enamel and dentine occurred …

Tandem Scanning Reflected Light Microscopy Of Primate Enamel, Alan Boyde, Lawrence Martin

Scanning Microscopy

Studies of the cross sectional packing arrangements of primate enamel prisms have been used in a number of recent studies in attempts to determine their taxonomic utility. Credibility of the results has been greatly influenced by the methods employed to examine enamel prism packing patterns and also by the limited sampling. We report here the use of a technique for the non destructive examination, in depth, of enamel prism packing patterns in modern and fossil primate teeth which has considerable advantages over any others so far used, and the preliminary results of a survey of enamel structural diversity in the …

The Root Surface: An Illustrated Review Of Some Scanning Electron Microscope Studies, Sheila J. Jones

Scanning Microscopy

This review paper highlights how the advent of a new type of surface microscopy in the late 1960s, scanning electron microscopy (SEM), was responsible for a fresh appraisal of the structure of the root surface. Details of the formation, resorption and repair of cementum, all surface phenomena, and the varied relationships and mineralization patterns of the two sets of fibres within cementum - the hall mark of the tissue - could be seen in a way and at a range of magnifications hitherto impossible. The major interpretational advances were made rapidly using secondary electron imaging of anorganic normal, exposed, carious …

The Influence Of Metal Substrates On The Electronic States Of Metal Overlayers, P. A. Dowben, M. Onellion, Y. J. Kime

Scanning Microscopy

The aim of this paper is to provide an introduction to the electronic structure of very thin film (one to ten monolayers) overlayers using examples from studies of Hg overlayers on Ag(100) and Fe thin film overlayers. Interracial states as a result of the interaction of the substrate and overlayer, as well as the new electronic states of the overlayer caused by a new crystallographic structure can modify the overlayer metal electronic structure. Additional changes in the overlayer electronic structure arise from the reduced dimensionality (2 dimensionality as opposed to 3 dimensionality) of the thin film. We discuss the photoemission …

Image Analysis And X-Ray Microanalysis In Cytochemistry, W. C. De Bruijn, H. K. Koerten, M. I. Cleton-Soeteman, C. J. G. Blok-Van Hoek

Scanning Microscopy

When cytochemical reaction products are homogeneously distributed within an organelle, point analyses suffice for the quantitative approach. However, quantitative analysis becomes tedious, when the elements in the reaction product are inhomogeneously distributed. Problems arise when elements from two reaction products have to be related to each other, or to endogenous cytological products (ferritin, haemosiderin, calcium, electron dense markers), either topographically or in concentration. When analyzing inhomogeneous/heteromorphical reaction product-containing organelles special attention has to be paid to measure and relate both volume and concentration. In this paper a relative simple structure (eosinophil granules) is chosen to demonstrate that the acquisition of …

A Scanning Electron Microscopy Study Of Approximal Premolar Surfaces From Fifteen Year Old Children Living In A Fluoridated Community, Lisbeth Holmen

Scanning Microscopy

The aim of the present study was to examine approximal enamel surfaces in the scanning electron microscope (SEM). Thirty premolars developed and erupted in an 'optimally' fluoridated (1 ppm) community had clinical indications of dental fluorosis and early signs of dental caries corresponding to the approximal contact area. The SEM-examination disclosed a spectrum of posteruptive changes ranging from isolated surface fractures to carious dissolution, abrasion and calcified microbial deposits. Conclusively, we found that teeth developed and erupted in areas with fluoridated water undergo similar posteruptive alterations due to prevailing environmental conditions as reported in teeth from low fluoride areas.