High Voltage Transmission Microscopy of Surveyor III Camera Shrouds

1971 ◽  
Vol 29 ◽  
pp. 138-139
Author(s):  
W. R. Duff ◽  
L. E. Thomas ◽  
R. M. Fisher ◽  
S. V. Radcliffe
Keyword(s):  
Alloy Sheet ◽  
Transmission Microscopy ◽  
Television Camera ◽  
Window Method ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Lunar Environment ◽  
Successful Retrieval ◽  
Materials Used ◽  
Abrasive Paper

Successful retrieval of the television camera and other components from the Surveyor III spacecraft by the Apollo 12 astronauts has provided a unique opportunity to study the effects of a known and relatively extensive exposure to the lunar environment. Microstructural effects including those produced by micro-meteorite impact, radiation damage (by both the solar wind and cosmic rays) and solar heating might be expected in the materials used to fabricate the spacecraft. Samples received were in the form of 1 cm2 of painted unpainted aluminum alloy sheet from the top of the camera visor (JPL Code 933) and the sides (935,936) and bottom (934) of the lower camera shroud. They were prepared for transmission electron microscopy by first hand-grinding with abrasive paper to a thickness of 0.006". The edges were lacquered and the sample electropolished in 10% perchloric methanol using the “window” method, to a thickness of ~0.001". Final thinning was accomplished by polishing 3 mm punched disks in an acetic-phosphoric-nitric acid solution.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Scanning Transmission Microscopy Applied to Thick Specimen

1972 ◽  
Vol 30 ◽  
pp. 452-453
Author(s):  
H. Koike ◽  
T. Matsuo ◽  
K. Ueno ◽  
M. Suzuki
Keyword(s):  
Psoas Muscle ◽  
Image Intensifier ◽  
Chromatic Aberration ◽  
Image Contrast ◽  
Transmission Microscopy ◽  
Crystalline Materials ◽  
Thick Specimen ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Microscope Image

Since the identification of single atoms was achieved by Crewe et al, scanning transmission microscopy has been put into pratical use. Recently they applied this method to the quantitative mass analysis of DNA.As pointed out previously the chromatic aberration which decreases the image contrast and quality, does not affect a scanning transmission image as it does a conventional transmission electron microscope image. Thus, the STEM method is advantageous for thick specimen. Further this method employs a high sensitive photomultiplier tube which also functions as an image intensifier. This detection method is effective for the observation of living specimens or easily damaged specimens. In this respect the scanning transmission microscope with high accelerating voltage is necessary.Since Uyeda's experiments of crystalline materials, many workers have been discussed how thick specimens can be observed by CTEM. With biological specimens, R. Szirmae reported on the decrease in the image contrast of rabbit psoas muscle sections at various accelerating voltages and specimen thicknesses.

Low-temperature annealing of YBa2Cu3O7-x

1992 ◽  
Vol 50 (1) ◽  
pp. 88-89
Author(s):  
R.L. Sabatini ◽  
Yimei Zhu ◽  
Masaki Suenaga ◽  
A.R. Moodenbaugh
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Oxygen Diffusion ◽  
Diffusion Rate ◽  
Oxygen Depletion ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Oxygen Diffusion Rate

Low temperature annealing (<400°C) of YBa2Cu3O7x in a ozone containing oxygen atmosphere is sometimes carried out to oxygenate oxygen deficient thin films. Also, this technique can be used to fully oxygenate thinned TEM specimens when oxygen depletion in thin regions is suspected. However, the effects on the microstructure nor the extent of oxygenation of specimens has not been documented for specimens exposed to an ozone atmosphere. A particular concern is the fact that the ozone gas is so reactive and the oxygen diffusion rate at these temperatures is so slow that it may damage the specimen by an over-reaction. Thus we report here the results of an investigation on the microstructural effects of exposing a thinned YBa2Cu3O7-x specimen in an ozone atmosphere using transmission electron microscopy and energy loss spectroscopy techniques.

Imaging sub-micron objects with light microscopy: Visualization of the T-4 bacteriophage

1989 ◽  
Vol 47 ◽  
pp. 834-835
Author(s):  
Malcolm Brown ◽  
Reynolds M. Delgado ◽  
Michael J. Fink
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Focal Plane ◽  
Phase Contrast ◽  
Dark Field ◽  
E Coli ◽  
Polystyrene Beads ◽  
Television Camera ◽  
Transmission Electron ◽  
Universal Microscope

While light microscopy has been used to image sub-micron objects, numerous problems with diffraction-limitations often preclude extraction of useful information. Using conventional dark-field and phase contrast light microscopy coupled with image processing, we have studied the following objects: (a) polystyrene beads (88nm, 264nm, and 557mn); (b) frustules of the diatom, Pleurosigma angulatum, and the T-4 bacteriophage attached to its host, E. coli or free in the medium. Equivalent images of the same areas of polystyrene beads and T-4 bacteriophages were produced using transmission electron microscopy.For light microscopy, we used a Zeiss universal microscope. For phase contrast observations a 100X Neofluar objective (N.A.=1.3) was applied. With dark-field, a 100X planachromat objective (N.A.=1.25) in combination with an ultra-condenser (N.A.=1.25) was employed. An intermediate magnifier (Optivar) was available to conveniently give magnification settings of 1.25, 1.6, and 2.0. The image was projected onto the back focal plane of a film or television camera with a Carl Zeiss Jena 18X Compens ocular.

scholarly journals ZnO Nanoparticles with Controllable Ce Content for Efficient Photocatalytic Degradation of MB Synthesized by the Polyol Method

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Gregorio Flores-Carrasco ◽  
Micaela Rodríguez-Peña ◽  
Ana Urbieta ◽  
Paloma Fernández ◽  
María Eugenia Rabanal
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Degradation ◽  
Doping Concentration ◽  
Polyol Method ◽  
Transmission Microscopy ◽  
Uv Illumination ◽  
Transmission Electron ◽  
Optical Luminescence ◽  
Pl Emission ◽  
Ce Content

This paper reports on the synthesis of Ce-doped ZnO (CZO) nanoparticles (NPs) by an alternative polyol method at low temperature. The method, facile and rapid, uses acetate-based precursors, ethylene glycol as solvent, and polyvinylpyrrolidone as capping agent. The effects of the Ce-doping concentration (ranging from 0 to 8.24 atomic%) on the structural, morphological, compositional, optical, luminescence, and photocatalytic properties of the NPs were investigated by several techniques. The structural findings confirmed that the CZO NPs have a typical hexagonal wurtzite-type structure with a preferred orientation along the (101) plane. The results obtained by Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) revealed that the NPs size decreased (from ~30 to ~16 nm) with an increase in the Ce-doping concentration. Energy Dispersive X-Ray Spectroscopy (EDS) and High Resolution Transmission Microscopy (HRTEM) results confirmed the incorporation of Ce ions into the ZnO lattice. Ce-doping influences the photoluminescence (PL) emission compared to that of pure ZnO. The PL emission is related to the presence of different kinds of defects, which could take part in charge transfer and/or trapping mechanisms, hence playing an essential role in the photocatalytic activity (PCA). In fact, in this work we report an enhancement of PCA as a consequence of Ce-doping. In this sense, the best results were obtained for samples doped with 3.24 atomic%, that exhibited a photocatalytic degradation efficiency close to 99% after 60 min ultraviolet (UV) illumination, thus confirming the viability of Ce-doping for environmental applications.

A Study on Tensile Deformation Features of Ni-Based Super-Alloy Prepared by EB-PVD

2011 ◽  
Vol 55-57 ◽  
pp. 251-256
Author(s):  
Li Ma ◽  
Ting Zhang ◽  
Xiao Li ◽  
Zhao Hui Hu
Keyword(s):  
Physical Vapor Deposition ◽  
Large Scale ◽  
Tensile Deformation ◽  
Alloy Sheet ◽  
Dislocation Climb ◽  
Dislocation Glide ◽  
Double Phase ◽  
Transmission Electron ◽  
Deformation Features ◽  
Super Alloy

Large-scale Ni-based super-alloy sheet has been prepared by electron beam physical vapor deposition (EB-PVD). Microstructure and the dislocation structures in the γ-γ′ double phase alloy under different temperature after tensile strain are studied with Transmission electron microscopy (TEM). The results show that the dislocation glide in single slip system and shearing mechanics, the dislocation climb with part shearing, absolute dislocation climb and cross slip, dislocation round are a course of the interacting degree between dislocation and γ′ phase gradually weakened under the tensile temperature from room temperature to high temperature, so as to decrease materials strength and increase plasticity.

Effect of Annealing Temperature on the Microstructure of 2195 Al-Li Alloy Sheet

2021 ◽  
Vol 1026 ◽  
pp. 49-58
Author(s):  
Bo Feng ◽  
Bai Qing Xiong
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Annealing Temperature ◽  
Testing Machine ◽  
Annealing Treatment ◽  
Alloy Sheet ◽  
Transmission Electron ◽  
Δ Phase ◽  
Backscattered Electron ◽  
Alloy Increase

The annealing temperature is a key parameter for the mechanical properties and microstructure control of the 2195 Al-Li alloy sheet in the annealing process. In the present study, the effect of annealing temperature on the microstructure of 2195 Al-Li alloy sheet was investigated using a general mechanical testing machine, scanning electron microscope (SEM), transmission electron microscope (TEM), and backscattered electron microscope (EBSD). It was found that the optimized annealing temperature for 2195Al-Li alloy sheet of H112 state is 400°C, the alloy sheet shows the satisfactory mechanical properties. In addition, with the increase of annealing temperature, the δ' phase, the θ' phase and the T1 phase are formed in the alloy sheet, which leads to the strength of the alloy increase. Furthermore, the annealing temperature obviously affect the texture component and intensity during annealing treatment process.

Review on Accumulative Roll Bonding (ARB) Techniques for Improving the Mechanical Properties of Multi-Layered Materials

2020 ◽  
Vol 979 ◽  
pp. 84-88
Author(s):  
A. Arun ◽  
Lakshmanan Poovazhgan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Accumulative Roll Bonding ◽  
Nanocrystalline Structure ◽  
Hardness Test ◽  
Roll Bonding ◽  
Transmission Electron ◽  
Ultrafine Grained ◽  
Materials Used ◽  
Number Of Passes

Accumulative Roll Bonding (ARB) is one among the techniques in Severe Plastic Deformation (SPD) which is used to produce ultrafine grains and nanocrystalline structure in the materials used. Tensile test, micro hardness test, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and bending tests are the various tests carried out to understand the grain refinement of ARB materials. ARB is carried out in homogenous and heterogeneous materials to bring out the useful applications of ultrafine grained materials. ARB process mainly carried out in room, warm and hot temperature. The variations in the structure of the material are obtained by changing the load applied on the roller and by increasing the number of passes. This review paper brings out how the mechanical properties of the materials are improved by ARB process

Characterisation of the Microstructure Evolution of Aged Grade 91 Steel

2020 ◽  
Author(s):  
Chang Che ◽  
Xiang Liu ◽  
Youqiao Huang ◽  
Qingchuan Pan ◽  
Gong Qian
Keyword(s):  
Microstructural Evolution ◽  
Microstructure Evolution ◽  
Power Plants ◽  
Optical Microscope ◽  
Laves Phases ◽  
Transmission Electron ◽  
Materials Used ◽  
Grade 91 ◽  
Grade 91 Steel

Abstract Grade 91 steel has high creep strength and has been used as the material of piping in 600°C USC power plants in China. The Grade 91 materials used in actual power plants are useful in estimating the changes of material properties caused by long-term aging and damage at low stress conditions. An understanding of the long-term microstructural evolution under actually used conditions is a key for the improvement of these heat resistant steels. In this article, microstructural evolution of Grade 91 steel under different service conditions in Chinese power plants was studied using optical microscope (OM), transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) techniques. The results show, M23C6, MX (V-rich particles; Nb-rich particles), and Laves phases were found to precipitate. A quantitative characterisation of microstructure evolution was evaluated during long-term exposure, focusing on the size of precipitates (M23C6 carbides, Laves phase, MX phase) for the Grade 91 steel after long-term service.

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