An improved method for paleoflood reconstruction and flooding phase identification, applied to the Meuse River in the Netherlands

Image shifts in out-of-focus dark field images have been used in the past to determine, for example, epitaxial relationships in thin films. A recent extension of the use of dark field image shifts has been to out-of-focus images in conjunction with stereoviewing to produce an artificial stereo image effect. The technique, called through-focus dark field electron microscopy or 2-1/2D microscopy, basically involves obtaining two beam-tilted dark field images such that one is slightly over-focus and the other slightly under-focus, followed by examination of the two images through a conventional stereoviewer. The elevation differences so produced are usually unrelated to object positions in the thin foil and no specimen tilting is required.In order to produce this artificial stereo effect for the purpose of phase separation and identification, it is first necessary to select a region of the diffraction pattern containing more than just one discrete spot, with the objective aperture.

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Phase identification in SiC whisker reinforced Al2O3-R2O3-based composites

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121168 ◽

1992 ◽

Vol 50 (1) ◽

pp. 152-153

Author(s):

C.M. Sung ◽

K.J. Ostreicher ◽

M.L. Huckabee ◽

S.T. Buljan

Keyword(s):

Analytical Electron Microscopy ◽

Phase Identification ◽

Reinforced Composites ◽

Ion Milling ◽

X Ray ◽

Binary Oxides ◽

Analytical Electron ◽

The Matrix ◽

Second Phases ◽

Convergent Beam

A series of binary oxides and SiC whisker reinforced composites both having a matrix composed of an α-(Al, R)2O3 solid solution (R: rare earth) have been studied by analytical electron microscopy (AEM). The mechanical properties of the composites as well as crystal structure, composition, and defects of both second phases and the matrix were investigated. The formation of various second phases, e.g. garnet, β-Alumina, or perovskite structures in the binary Al2O3-R2O3 and the ternary Al2O3-R2O3-SiC(w) systems are discussed.Sections of the materials having thicknesses of 100 μm - 300 μm were first diamond core drilled. The discs were then polished and dimpled. The final step was ion milling with Ar+ until breakthrough occurred. Samples prepared in this manner were then analyzed using the Philips EM400T AEM. The low-Z energy dispersive X-ray spectroscopy (EDXS) data were obtained and correlated with convergent beam electron diffraction (CBED) patterns to identify phase compositions and structures. The following EDXS parameters were maintained in the analyzed areas: accelerating voltage of 120 keV, sample tilt of 12° and 20% dead time.

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An Improved Method for the Preparation and TEM Examination of Sharp Pointed Tips used in APFIM and STM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134107 ◽

1990 ◽

Vol 48 (2) ◽

pp. 102-103

Author(s):

E.A. Fischione ◽

P.E. Fischione ◽

J.J. Haugh ◽

M.G. Burke

Keyword(s):

Atom Probe ◽

Preparation Process ◽

Improved Method ◽

Ion Milling ◽

Polishing Process ◽

Probe Field ◽

Scanning Tunnelling ◽

Stm Tips ◽

Tunnelling Microscopy ◽

Ion Microscopy

A common requirement for both Atom Probe Field-Ion Microscopy (APFIM) and Scanning Tunnelling Microscopy (STM) is a sharp pointed tip for use as either the specimen (APFIM) or the probe (STM). Traditionally, tips have been prepared by either chemical or electropolishing techniques. Recently, ion-milling has been successfully employed in the production of APFIM tips [1]. Conventional electropolishing techniques are applicable to a wide variety of metals, but generally require careful manual adjustments during the polishing process and may also be time-consuming. In order to reduce the time and effort involved in the preparation process, a compact, self-contained polishing unit has been developed. This system is based upon the conventional two-stage electropolishing technique in which the specimen/tip blank is first locally thinned or “necked”, and subsequently electropolished until separation occurs.[2,3] The result of this process is the production of two APFIM or STM tips. A mechanized polishing unit that provides these functions while automatically maintaining alignment has been designed and developed.

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Immunoelectron microscopic localization of elastic tissue in archival material using an improved method

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161539 ◽

1990 ◽

Vol 48 (3) ◽

pp. 794-795

Author(s):

J. C. Fanning ◽

J. F. White ◽

R. Polewski ◽

E. G. Cleary

Keyword(s):

Normal Animal ◽

Animal Tissue ◽

Elastic Tissue ◽

Human Tissues ◽

Improved Method ◽

Tissue Samples ◽

Archival Material ◽

Immuno Electron Microscopy ◽

Arteries And Veins ◽

Biochemical Examination

Elastic tissue is an important component of the walls of arteries and veins, of skin, of the lungs and in lesser amounts, of many other tissues. It is responsible for the rubber-like properties of the arteries and for the normal texture of young skin. It undergoes changes in a number of important diseases such as atherosclerosis and emphysema and on exposure of skin to sunlight.We have recently described methods for the localizationof elastic tissue components in normal animal and human tissues. In the study of developing and diseased tissues it is often not possible to obtain samples which have been optimally prepared for immuno-electron microscopy. Sometimes there is also a need to examine retrospectively samples collected some years previously. We have therefore developed modifications to our published methods to allow examination of human and animal tissue samples obtained at surgery or during post mortem which have subsequently been: 1. stored frozen at -35° or -70°C for biochemical examination; 2.

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Applications of SEM/EDXA in cement clinker investigation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177489 ◽

1990 ◽

Vol 48 (4) ◽

pp. 870-871

Author(s):

Arezki Tagnit-Hamou ◽

Shondeep L. Sarkar

Keyword(s):

Mineralogical Composition ◽

Physicochemical Characteristics ◽

Cement Clinker ◽

Accurate Information ◽

Phase Identification ◽

History Of ◽

Bulk Chemical ◽

Resolution Imaging ◽

Proven Method ◽

Instantaneous Chemical

All the desired properties of cement primarily depend on the physicochemical characteristics of clinker from which the cement is produced. The mineralogical composition of the clinker forms the most important parameter influencing these properties.Optical microscopy provides reasonably accurate information pertaining to the thermal history of the clinker, while XRDA still remains the proven method of phase identification, and bulk chemical composition of the clinker can be readily obtained from XRFA. Nevertheless, all these microanalytical techniques are somewhat limited in their applications, and SEM/EDXA combination fills this gap uniquely by virtue of its high resolution imaging capability and possibility of instantaneous chemical analysis of individual phases.Inhomogeneities and impurities in the raw meal, influence of kiln conditions such as sintering and cooling rate being directly related to the microstructure can be effectively determined by SEM/EDXA. In addition, several physical characteristics of cement, such as rhcology, grindability and hydraulicity also depend on the clinker microstructure.

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