scholarly journals Snow replica method for three-dimensional X-ray microtomographic imaging

2009 ◽  
Vol 55 (192) ◽  
pp. 631-639 ◽  
Author(s):  
Martin Heggli ◽  
Esther Frei ◽  
Martin Schneebeli
Keyword(s):  
High Vacuum ◽  
Three Dimensional ◽  
Electromagnetic Properties ◽  
Micro Ct ◽  
X Ray ◽  
Automatic Image Processing ◽  
Very High Spatial Resolution ◽  
Manual Interaction ◽  
Very High ◽  
Snow Samples

AbstractVisualization and quantification of snow structures at a scale of a few millimetres is important in understanding the mechanical, thermal and electromagnetic properties of snow. Surface sections and, to an even greater degree, three-dimensional (3-D) reconstructions of cast snow samples are difficult to prepare, and automatic image processing is notoriously difficult and often requires manual evaluation. Here, we present a new method to measure the 3-D structure of cast snow samples. Snow samples cast with diethyl phthalate (DEP) and frozen are cut to a sample size a few centimetres in diameter and up to 10 cm in height. The ice of these samples is then sublimated in high vacuum and the remaining negative structure (replica) is imaged using X-ray microtomography (micro-CT). The accuracy of the method is demonstrated by comparing micro-CT scans of the original snow structure and the replica. The method described here allows easy transportation of samples, requires little manual interaction, has a very high spatial resolution of up to 10 μm and is environmentally friendly.

Recent Developments In Monochromatic Microprobe X-Ray Fluorescence (MMXRF)

1998 ◽  
Vol 4 (S2) ◽  
pp. 378-379
Author(s):  
Z. W. Chen ◽  
D. B. Wittry
Keyword(s):  
Materials Science ◽  
High Vacuum ◽  
Three Dimensional ◽  
High Sensitivity ◽  
X Rays ◽  
Fluorescence Excitation ◽  
X Ray ◽  
Quantitative Microanalysis ◽  
Recent Developments ◽  
Fifth Order

A monochromatic x-ray microprobe based on a laboratory source has recently been developed in our laboratory and used for fluorescence excitation. This technique provides high sensitivity (ppm to ppb), nondestructive, quantitative microanalysis with minimum sample preparation and does not require a high vacuum specimen chamber. It is expected that this technique (MMXRF) will have important applications in materials science, geological sciences and biological science.Three-dimensional focusing of x-rays can be obtained by using diffraction from doubly curved crystals. In our MMXRF setup, a small x-ray source was produced by the bombardment of a selected target with a focused electron beam and a toroidal mica diffractor with Johann pointfocusing geometry was used to focus characteristic x-rays from the source. In the previous work ∼ 108 photons/s were obtained in a Cu Kα probe of 75 μm × 43 μm in the specimen plane using the fifth order reflection of the (002) planes of mica.

scholarly journals A Preliminary Report on the Use of Bench-Top X-Ray Micro-Computerised Tomography to Study the Malpighian Tubules of the Overwintering Seven Spotted LadybirdCoccinella septempunctataL. (Coleoptera: Coccinellidae)

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Duncan Bell ◽  
Lewis Woolnough ◽  
David Mortimore ◽  
Nick Corps ◽  
Diana M. Hudson ◽  
...  
Keyword(s):  
Coccinella Septempunctata ◽  
Ct Scanning ◽  
Small Sample ◽  
Malpighian Tubules ◽  
Micro Ct ◽  
Computerised Tomography ◽  
X Ray ◽  
High Concentrations ◽  
Very High ◽  
Metallic Pollutants

The application of micro-CT scanning techniques on a small sample of “Seven-spot ladybirds”Coccinella septempunctata,collected in December 2009, identified an accumulation of material with a very high, relative X-ray attenuation value in the malpighian tubules of most but not all of the individuals sampled. The passage of metals such as cadmium in soil through a food chain to finally accumulate in high concentrations in ladybirds and lacewings has been previously reported. The identification of the dense material found in our sample of ladybirds, its origin, and the process by which it accumulates in, and is processed by, the malpighian tubules is the challenge ahead. The authors speculate that a straightforward means of monitoring levels of metallic pollutants in the environment might emerge.

scholarly journals The Determination Of Diffusive Tortuosity In Concrete Specimens Using X-Ray Microtomography

2015 ◽  
Vol 60 (2) ◽  
pp. 1115-1119 ◽  
Author(s):  
Z. Ranachowski ◽  
D. Jóźwiak-Niedźwiedzka ◽  
P. Ranachowski ◽  
M. Dąbrowski ◽  
S. Kudela ◽  
...  
Keyword(s):  
Random Walk ◽  
Three Dimensional ◽  
Micro Ct ◽  
Connectivity Analysis ◽  
Pore Connectivity ◽  
Cement Ratio ◽  
X Ray ◽  
Water To Cement Ratio ◽  
Random Walk Simulation

Abstract The paper presents a method of pore connectivity analysis applied to specimens of cement based composites differing in water to cement ratio. The method employed X-ray microtomography (micro-CT). Microtomography supplied digitized three-dimensional radiographs of small concrete specimens. The data derived from the radiographs were applied as an input into the application based on the algorithm called ‘random walk simulation’. As the result a parameter called diffusive tortuosity was established and compared with estimated porosity of examined specimens.

Three-dimensional imaging of whole mouse models: comparing nondestructive X-ray phase-contrast micro-CT with cryotome-based planar epi-illumination imaging

2013 ◽  
Vol 253 (1) ◽  
pp. 24-30 ◽  
Author(s):  
A. TAPFER ◽  
M. BECH ◽  
I. ZANETTE ◽  
P. SYMVOULIDIS ◽  
S. STANGL ◽  
...  
Keyword(s):  
Mouse Models ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Micro Ct ◽  
Three Dimensional Imaging ◽  
X Ray

scholarly journals Micro-CT study of Middle Ordovician Spumellaria (radiolarians) from western Newfoundland, Canada

2020 ◽  
Vol 94 (3) ◽  
pp. 417-435 ◽  
Author(s):  
Sarah Kachovich ◽  
Jonathan C. Aitchison
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Detailed Examination ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Lower Paleozoic ◽  
X Ray ◽  
Middle Ordovician ◽  
Radiolarian Assemblage ◽  
Taxonomic Groups

AbstractA new, previously undescribed Middle Ordovician (middle Darriwilian: Dw2) radiolarian assemblage has been recovered from the Table Cove Formation at Piccadilly Quarry, western Newfoundland. Constituents of the fauna described herein are both distinctive and exceptionally well preserved. Three-dimensional X-ray micro-computed tomography (μ-CT) is used to make a detailed examination of four key spumellarian specimens. This technology enables visualization of hitherto ambiguous details of the internal morphologies of key lower Paleozoic taxonomic groups, among which a lack of knowledge has impeded resolution of higher taxonomic rankings.

scholarly journals Statistical Assessment of the Microstructure of Barite Aggregate from Different Deposits Using X-Ray Microtomography and Optical Microscopy

2017 ◽  
Vol 62 (2) ◽  
pp. 697-702
Author(s):  
N. Żołek ◽  
Z. Ranachowski ◽  
P. Ranachowski ◽  
D. Jóźwiak-Niedźwiedzka ◽  
S. Kudela ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Barium Sulfate ◽  
Three Dimensional ◽  
Empty Space ◽  
Paper Analysis ◽  
Micro Ct ◽  
Statistical Assessment ◽  
Thin Sections ◽  
X Ray ◽  
Additional Information

AbstractTwo different barite ore (barium sulfate BaSO4) specimens from different localizations were tested and described in this paper. Analysis of the microstructure was performed on polished sections, and on thin sections using X-ray microtomography (micro-CT), and optical microscopy (MO). Microtomography allowed obtaining three-dimensional images of the barite aggregate specimens. In the tomograms, the spatial distribution of the other polluting phases, empty space as well as cracks, pores, and voids – that exceeded ten micrometers of diameter-were possible to visualize. Also, the micro-CT allowed distinguishing between minerals of different density, like SiO2and BaSO4. Images obtained and analyzed on thin sections with various methods using the optical microscopy in transmitted light delivered additional information on the aggregate microstructure, i.e. allow for estimation of the different kinds of inclusions (like the different density of the minerals) in the investigated specimens. Above methods, which were used in the tests, completed each another in order to supply a set of information on inclusions’ distribution and to present the important differences of the barite aggregate specimens microstructure.

Sarcoptes scabiei var. hominis: Three-dimensional structure of a female imago and crusted scabies lesions by X-ray micro-CT

2009 ◽  
Vol 122 (4) ◽  
pp. 268-272 ◽  
Author(s):  
Hideyuki Yoshimura ◽  
Takuji Ohigashi ◽  
Masayuki Uesugi ◽  
Kentaro Uesugi ◽  
Toshiaki Higashikawa ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Sarcoptes Scabiei ◽  
Dimensional Structure ◽  
Micro Ct ◽  
X Ray ◽  
Three Dimensional Structure ◽  
Crusted Scabies

X-Ray Tomographic Microscopy of Nicalon Preforms and Chemical Vapor Infiltrated Nicalon/Silicon Carbide Composites

1991 ◽  
Vol 250 ◽  
Author(s):  
M. D. Butts ◽  
S. R. Stock ◽  
J. H. Kinney ◽  
T. L. Starr ◽  
M. C. Nichols ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
High Resolution Computed Tomography ◽  
X Ray ◽  
Sic Fiber ◽  
Sic Composites ◽  
And Control ◽  
Fiber Preforms ◽  
Very High

AbstractFollowing the evolving microstructure of composites through all stages of chemical vapor infiltration (CVI) is a key to improved understanding and control of the process. X-ray Tomographic Microscopy (XTM), i.e., very high resolution computed tomography, allows the microstructure of macroscopic volumes of a composite to be imaged nondestructively with resolution approaching one micrometer. Results obtained with XTM on dense SiC/SiC composites and on woven SiC fiber preforms illustrate how details of the densification process can be followed using this technique during interruptions in processing. Ways in which the three-dimensional microstructural information may be used to improve modeling are also indicated.

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