X-ray computed tomographic and focused ion beam/electron microscopic investigation of coating defects in niobium-coated copper superconducting radio-frequency cavities

2021 ◽  
pp. 125062
Author(s):  
S. Aliasghari ◽  
P. Skeldon ◽  
X. Zhou ◽  
A. Gholinia ◽  
X. Zhang ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Beam Electron ◽  
X Ray ◽  
Computed Tomographic ◽  
Superconducting Radio Frequency ◽  
X Ray Computed

scholarly journals A lathe system for micrometre-sized cylindrical sample preparation at room and cryogenic temperatures

2020 ◽  
Vol 27 (2) ◽  
pp. 472-476
Author(s):  
Mirko Holler ◽  
Johannes Ihli ◽  
Esther H. R. Tsai ◽  
Fabio Nudelman ◽  
Mariana Verezhak ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Cylindrical Sample ◽  
X Ray ◽  
X Ray Computed ◽  
Cryogenic Conditions ◽  
Cylindrical Samples ◽  
Potential Use

A simple two-spindle based lathe system for the preparation of cylindrical samples intended for X-ray tomography is presented. The setup can operate at room temperature as well as under cryogenic conditions, allowing the preparation of samples down to 20 and 50 µm in diameter, respectively, within minutes. Case studies are presented involving the preparation of a brittle biomineral brachiopod shell and cryogenically fixed soft brain tissue, and their examination by means of ptychographic X-ray computed tomography reveals the preparation method to be mainly free from causing artefacts. Since this lathe system easily yields near-cylindrical samples ideal for tomography, a usage for a wide variety of otherwise challenging specimens is anticipated, in addition to potential use as a time- and cost-saving tool prior to focused ion-beam milling. Fast sample preparation becomes especially important in relation to shorter measurement times expected in next-generation synchrotron sources.

scholarly journals An Electron Microscopic Investigation of the Cell Wall Organization of Conifer Tracheids and Conifer Cambium

1950 ◽  
Vol 3 (3) ◽  
pp. 265 ◽  
Author(s):  
AJ Hodge ◽  
AB Wardrop
Keyword(s):  
Cell Wall ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Electron Micrograph ◽  
Electron Microscopic ◽  
X Ray ◽  
Inner Surface ◽  
Cell Wall Organization ◽  
Optical Evidence

An electron micrograph of a replica of the inner surface of the secondarycell wall of a conifer tracheid, demonstrating the almost transverse orientationof the microfibrils in this layer, is presented. This evidence provides confirmationof the type of cell wall organization of conifer tracheids proposed inother investigations on the basis of X-ray and optical evidence and of microscopicexamination. The existence of fibrils of 50-100 A in diameter has beendemonstrated in cell wall fragments obtained by the disintegration of cambiuminitials and of conifer tracheids. It is suggested that these microfibrilsmay correspond to the "micelles" or "crystalline regions" inferred from X-rayexamination.

scholarly journals Three dimensional characterisation of chromatography bead internal structure using X-ray computed tomography and focused ion beam microscopy

2018 ◽  
Vol 1566 ◽  
pp. 79-88 ◽  
Author(s):  
T.F. Johnson ◽  
J.J. Bailey ◽  
F. Iacoviello ◽  
J.H. Welsh ◽  
P.R. Levison ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
X Ray ◽  
X Ray Computed

Light and electron microscopic investigation of adenohypophyses of germfree, food-restricted, and germfree-food restricted aging, male lobund-wistar rats

1988 ◽  
Vol 46 ◽  
pp. 352-353
Author(s):  
G. Ilse ◽  
K. Kovacs ◽  
N. Ryan ◽  
T. Sano ◽  
L. Stefaneanu ◽  
...  
Keyword(s):  
Wistar Rats ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Aging Male ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
Sprague Dawley Rats ◽  
Old Rats ◽  
Ad Libitum ◽  
Microscopic Findings

Germfree state and food restriction have been shown to increase life span and delay tumor occurrence in rats. We report here the histologic, immunocytochemical and electron microscopic findings of adenohypophyses of aging, male Lobund-Wistar rats raised at Lobund Laboratories. In our previous study, the morphologic changes in the adenohypophyses of old rats have been extensively investigated by histology, immunocytochemistry and electron microscopy. Lactotroph adenomas were frequent in Long-Evans and Sprague-Dawley rats, whereas gonadotroph adenomas were frequent in Sprague-Dawley and Wistar rats.Male Lobund-Wistar rats were divided into four groups: 1) conventional, which were raised under normal non-germfree environment and received food ad libitum; 2) germfree-food ad libitum; 3) conventional environment-food restricted and 4) germfree-food restricted. The adenohypophyses were removed from 6-month-, 18-month- and 30-month-old rats. For light microscopy, adenohypophyses were fixed in formalin and embedded in paraffin.

An Electron Microscopic Study of the Acute Effects of Hypothalamic Releasing Factors on the Anterior Pituitary Gland

1968 ◽  
Vol 26 ◽  
pp. 232-233
Author(s):  
P.W. Coates ◽  
E.A. Ashby ◽  
L. Krulich ◽  
A. Dhariwal ◽  
S. McCann
Keyword(s):  
Anterior Pituitary ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Thin Sections ◽  
Dense Membrane ◽  
Membrane Bound ◽  
Releasing Factors

The morphologic effects on somatotrophs of crude sheep hypothalamic extract prepared from stalk-median eminence were studied by electron microscopy in conjunction with concurrently run bioassays performed on the same tissue samples taken from young adult male Sherman rats.Groups were divided into uninjected controls and injected experimentals sacrificed at 5', 15', and 30' after injection. Half of each anterior pituitary was prepared for electron microscopic investigation, the other half for bioassay. Fixation using collidine buffered osmium tetroxide was followed by dehydration and embedment in Maraglas. Uranyl acetate and lead citrate were used as stains. Thin sections were examined in a Philips EM 200.Somatotrophs from uninjected controls appeared as described in the literature (Fig. 1). In addition to other components, these cells contained moderate numbers of spherical, electron-dense, membrane-bound granules approximately 350 millicrons in diameter.

Fine Structural Classification of Chromophobe Adenomas of the Human Pituitary Gland

1975 ◽  
Vol 33 ◽  
pp. 378-379
Author(s):  
K. Kovacs ◽  
E. Horvath
Keyword(s):  
Pituitary Adenomas ◽  
Secretory Activity ◽  
Microscopic Investigation ◽  
Uranyl Acetate ◽  
Electron Microscopic Investigation ◽  
Electron Microscopic ◽  
Human Pituitary ◽  
Cytoplasmic Staining ◽  
Human Pituitary Gland ◽  
Microscopic Features

Chromophobe pituitary adenomas arise from adenohypophysial cells and fail to exhibit cytoplasmic staining with conventional acid or basic dyes by light microscopy. The aim of the present work was to study the electron microscopic features of these tumors, to separate them into distinct entities and to correlate their fine structural appearances with secretory activity.Among 48 surgically removed various pituitary adenomas 30 tumors were found which, based on the tinctorial characteristics of the cytoplasm, corresponded to chromophobe adenomas. For electron microscopic investigation pieces of these tumors were fixed in 2.5 per cent glutaraldehyde in Sorensen's buffer, post fixed in 1 per cent osmium tetroxide in Millonig's buffer, dehydrated in graded ethanol and embedded in Epon 812. Ultrathin sections were stained with uranyl acetate and lead citrate.By electron microscopy it was possible to separate chromophobe adenomas into 3 distinct entities: 1) adenomas consisting of sparsely granulated growth hormone cells (7 cases).

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