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.

scholarly journals Application of X-Ray Microtomography and Optical Microscopy to Determine the Microstructure of Concrete Penetrated by Carbon Dioxide/ Zastosowanie Mikrotomografii Komputerowej I Mikroskopii Optycznej Do Oceny Mikrostruktury Betonów Poddanych Działaniu Co2

2014 ◽  
Vol 59 (4) ◽  
pp. 1441-1447 ◽  
Author(s):  
Z. Ranachowski ◽  
D. Józwiak-Niedzwiedzka ◽  
P. Ranachowski ◽  
F. Rejmund ◽  
M. Dabrowski ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Composite Materials ◽  
Optical Microscopy ◽  
Material Properties ◽  
Three Dimensional ◽  
Basic Material ◽  
Material Microstructure ◽  
Thin Sections ◽  
X Ray ◽  
Additional Information

Abstract In the paper two advanced methods for testing cement based composites are described and compared. These are X-ray microtomography and optical microscopy. Microtomography supplies three-dimensional images of small concrete specimens. In the tomograms all cracks, pores and other voids and inclusions, that exceed a few micrometers, are shown. Such visualisation can become a valuable tool for analysis of the basic material properties. Images obtained on thin sections and analysed with various methods on optical microscopes supply additional information on material microstructure that cannot be obtained in tomograms. For example it is relatively easy to determine zone penetrated by CO2 ingress. These two methods, presented on examples of tests, complete each another in order to supply a set of information on composition and defects of tested composite materials.

3-D reconstruction of molecular shape from microcrystal thin sections

1983 ◽  
Vol 41 ◽  
pp. 748-749
Author(s):  
S. Cusack ◽  
J.-C. Jésior
Keyword(s):  
Three Dimensional ◽  
Molecular Shape ◽  
Biological Molecules ◽  
Fourier Space ◽  
Single Particles ◽  
Thin Sections ◽  
Standard Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dimensional Reconstruction

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

scholarly journals Microstructural characterization of snow, firn and ice

2019 ◽  
Vol 377 (2146) ◽  
pp. 20180162 ◽  
Author(s):  
Ian Baker
Keyword(s):  
Optical Microscopy ◽  
Microstructural Characterization ◽  
Theme Issue ◽  
Thin Sections ◽  
X Ray ◽  
The Future ◽  
Microscopy Techniques

This paper provides an overview of techniques used to characterize the microstructure of snow, firn and ice. These range from traditional optical microscopy techniques such as examining thin sections between crossed polarizers to various electron-optical and X-ray techniques. Techniques that could have an impact on microstructural characterization of snow, firn and ice in the future are briefly outlined. This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets’.

scholarly journals Three-dimensional visualization of fossil flowers, fruits, seeds, and other plant remains using synchrotron radiation X-ray tomographic microscopy (SRXTM): new insights into Cretaceous plant diversity

2014 ◽  
Vol 88 (4) ◽  
pp. 684-701 ◽  
Author(s):  
Else Marie Friis ◽  
Federica Marone ◽  
Kaj Raunsgaard Pedersen ◽  
Peter R. Crane ◽  
Marco Stampanoni
Keyword(s):  
Synchrotron Radiation ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Fossil Plants ◽  
Post Processing ◽  
Thin Sections ◽  
X Ray ◽  
Rapid Acquisition ◽  
Fossil Material ◽  
Plant Fossil

The application of synchrotron radiation X-ray tomographic microscopy (SRXTM) to the study of mesofossils of Cretaceous age has created new possibilities for the three-dimensional visualization and analysis of the external and internal structure of critical plant fossil material. SRXTM provides cellular and subcellular resolution of comparable or higher quality to that obtained from permineralized material using thin sections or the peel technique. SRXTM also has the advantage of being non-destructive and results in the rapid acquisition of large quantities of data in digital form. SRXTM thus refocuses the effort of the investigator from physical preparation to the digital post-processing of X-ray tomographic data, which allows great flexibility in the reconstruction, visualization, and analysis of the internal and external structure of fossil material in multiple planes and in two or three dimensions. A review of recent applications in paleobotany demonstrates that SRXTM will dramatically expand the level of information available for diverse fossil plants. Future refinement of SRXTM approaches that further increases resolution and eases digital post-processing, will transform the study of mesofossils and create new possibilities for advancing paleobotanical knowledge. We illustrate these points using a variety of Cretaceous mesofossils, highlighting in particular those cases where SRXTM has been essential for resolving critical structural details that have enhanced systematic understanding and improved phylogenetic interpretations.

Scanning texture analysis of lamellar bone using microbeam synchrotron X-ray radiation

2007 ◽  
Vol 40 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Wolfgang Wagermaier ◽  
Himadri S. Gupta ◽  
Aurélien Gourrier ◽  
Oskar Paris ◽  
Paul Roschger ◽  
...  
Keyword(s):  
Texture Analysis ◽  
Three Dimensional ◽  
Compact Bone ◽  
Axis Orientation ◽  
Thin Sections ◽  
X Ray ◽  
Synthetic Materials ◽  
Mineralized Tissues ◽  
Lamellar Texture ◽  
Dimensional Distribution

Texture analysis with microbeam scanning diffraction enables the local mapping of three-dimensional crystallite orientation in heterogeneous natural and synthetic materials. Cortical (compact) bone is an example of a hierarchically structured biocomposite, which is built mainly of cylindrical osteons, having a lamellar texture at the micrometre level. In this work, a combination of microbeam synchrotron X-ray texture analysis with thin sections of osteonal bone is used to measure the three-dimensional distribution of thec-axis orientation of the mineral apatite in bone with positional resolution of 1 µm. The data reduction procedure needed to go from the stereographic projection of X-ray intensity to the determination of the local orientation of mineralized collagen fibrils is described. The procedure can be applied to other mineralized tissues (such as trabecular bone and chitin) with micrometre scale and biologically controlled fibrillar texture.

scholarly journals A new on-axis multimode spectrometer for the macromolecular crystallography beamlines of the Swiss Light Source

2009 ◽  
Vol 16 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Robin L. Owen ◽  
Arwen R. Pearson ◽  
Alke Meents ◽  
Pirmin Boehler ◽  
Vincent Thominet ◽  
...  
Keyword(s):  
Light Source ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Additional Information ◽  
Swiss Light Source ◽  
Induced Changes ◽  
Insight Into

X-ray crystallography at third-generation synchrotron sources permits tremendous insight into the three-dimensional structure of macromolecules. Additional information is, however, often required to aid the transition from structure to function. In situ spectroscopic methods such as UV–Vis absorption and (resonance) Raman can provide this, and can also provide a means of detecting X-ray-induced changes. Here, preliminary results are introduced from an on-axis UV–Vis absorption and Raman multimode spectrometer currently being integrated into the beamline environment at X10SA of the Swiss Light Source. The continuing development of the spectrometer is also outlined.

The phase problem for one-dimensional crystals

2017 ◽  
Vol 73 (2) ◽  
pp. 140-150 ◽  
Author(s):  
Rick P. Millane
Keyword(s):  
A Priori ◽  
Three Dimensional ◽  
Phase Problem ◽  
One Dimensional ◽  
X Ray ◽  
Additional Information ◽  
Laser Sources ◽  
Fibre Diffraction ◽  
Low Dimensional ◽  
Molecular Envelope

The phase problem for diffraction amplitudes measured from a one-dimensional crystal is examined. In the absence of anya prioriinformation, the solution to this problem is shown to be unique up to a parameterized, low-dimensional set of solutions. Minimal additionala prioriinformation is expected to render the solution unique. The effects of additional information such as positivity, molecular envelope and helical symmetry on uniqueness are characterized. The results are pertinent to structural studies of polymeric and rod-like biomolecular assemblies that form one-dimensional, rather than three-dimensional, crystals. This shows the potential forab initiophasing of diffraction data from single such assemblies measured using new X-ray free-electron laser sources. Such an approach would circumvent the complicated inversion of cylindrically averaged diffraction that is necessary in traditional X-ray fibre diffraction analysis.

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

Three-Dimensional Coherent X-Ray Diffraction Microscopy

MRS Bulletin ◽  
2004 ◽  
Vol 29 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Ian K. Robinson ◽  
Jianwei Miao
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Real Space ◽  
Objective Lens ◽  
X Rays ◽  
X Ray Diffraction ◽  
Space Images ◽  
Thin Sections ◽  
X Ray ◽  
Penetration Ability

AbstractX-rays have been widely used in the structural analysis of materials because of their significant penetration ability, at least on the length scale of the granularity of most materials. This allows, in principle, for fully three-dimensional characterization of the bulk properties of a material. One of the main advantages of x-ray diffraction over electron microscopy is that destructive sample preparation to create thin sections is often avoidable. A major disadvantage of x-ray diffraction with respect to electron microscopy is its inability to produce real-space images of the materials under investigation—there are simply no suitable lenses available. There has been significant progress in x-ray microscopy associated with the development of lenses, usually based on zone plates, Kirkpatrick–Baez mirrors, or compound refractive lenses. These technologies are far behind the development of electron optics, particularly for the large magnification ratios needed to attain high resolution. In this article, the authors report progress toward the development of an alternative general approach to imaging, the direct inversion of diffraction patterns by computation methods. By avoiding the use of an objective lens altogether, the technique is free from aberrations that limit the resolution, and it can be highly efficient with respect to radiation damage of the samples. It can take full advantage of the three-dimensional capability that comes from the x-ray penetration. The inversion step employs computational methods based on oversampling to obtain a general solution of the diffraction phase problem.

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