Use of the Cryoscan apparatus for observation of freeze-fractured planes of a sensitive Quebec clay in scanning electron microscopy

1982 ◽  
Vol 19 (1) ◽  
pp. 111-114 ◽  
Author(s):  
Pierre Delage ◽  
Daniel Tessier ◽  
Martine Marcel-Audiguier

The cryoscan is an apparatus equipping the JEOL scanning electron microscopes, and allowing the observation of freeze-fracture planes of samples whose temperature is maintained below −100 °C. The application of this method to a sensitive clay from Quebec shows an aggregated structure, the aggregates being separated by 1 μm size voids.

1997 ◽  
Vol 3 (S2) ◽  
pp. 1193-1194
Author(s):  
Brendan J. Griffin

Most scanning electron microscopy is performed at low magnification; applications utilising the large depth of field nature of the SEM image rather than the high resolution aspect. Some environmental SEMs have a particular limitation in that the field of view is restricted by a pressure limiting aperture (PLA) at the beam entry point of the specimen chamber. With the original ElectroScan design, the E-3 model ESEM utilised a 500 urn aperture which gave a very limited field of view (∼550um diameter at a 10mm working distance [WD]). An increase of aperture size to ∼lmm provided an improved but still unsatisfactory field of view. The simplest option to increase the field of view in an ESEM was noted to be a movement of the pressure and field, limiting aperture back towards the scan coils1. This approach increased the field of view to ∼2mm, at a 10mm WD. A commercial low magnification device extended this concept and indicated the attainment of conventional fields of view.


Author(s):  
J. E. Ubelaker ◽  
R. D. Specian ◽  
V. F. Allison

Among the parasitic flatworms, only members of the trematoda have exploited nearly every conceivable niche. Since physiological demands in each habitat present special problems in eluding the host response as well as obtaining nourishment the surface epithelia of such organisms warrant special attention. To gain an appreciation of tegumental diversity in the trematoda, representative trematodes from numerous habitats in their respective hosts were examined by scanning electron microscopySpecimens were collected from natural infections, fixed in paraformaldehyde and dehydrated in alcohol. Ethanol was exchanged with amyl acetate prior to CO2 drying in a Denton DCP-1 critical point dryer. The dried specimens were mounted on metal holders, outgassed and rotary coated with gold-palladium. These were then examined with the ISI Mini-SEM and AMR 1000 scanning electron microscopes.


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):  
M. Spector ◽  
A. C. Brown

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.


1994 ◽  
Vol 117 (3) ◽  
pp. 399-401 ◽  
Author(s):  
Stephen A. Updegraff ◽  
Marguerite B. McDonald ◽  
Roger W. Beuerman

2016 ◽  
Vol 61 (5) ◽  
Author(s):  
Youssef S. Al Jabbari ◽  
Raymond Fournelle ◽  
Mirae Al Qhatani ◽  
Spiros Zinelis

AbstractThe aim was to determine the fracture mechanism of two clinically failed ParaPost drills. First, the fracture planes were analyzed by scanning electron microscopy (SEM). The drill end of one of the fractured pieces of each drill was then embedded in resin and after being metallographically ground and polished, was chemically etched. The microstructure and elemental composition were then examined by SEM/EDS analysis while hardness was determined with a Vickers testing device. Fractographic analysis revealed that both drills failed in a brittle manner and showed a pattern characteristic of a


1997 ◽  
Vol 5 (1) ◽  
pp. 14-15
Author(s):  
Vivian Robinson

Ever since electron microscopes were developed, it has been the goal of microscopists to observe specimens in their natural state, free from artefacts which can often be introduced through specimen preparation. For most biological specimens, that includes the presence of water. With a pressure of 10-4 torr or lower required to operate a scanning electron microscope (SEM), liquid water, which required a pressure of above 5 torr, was clearly a problem.Although several attempts had been made to examine hydrated specimens in a SEM, the first published results of water imaged in a stable and reproducible manner in the SEM, were presented at the Eighth International Congress on Electron Microscopy in Canberra in 1974 (Robinson, 1974).


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