The optical determination of preferred orientation in clays and its application to the study of microstructure in consolidated kaolin. І

1967 ◽  
Vol 300 (1461) ◽  
pp. 218-234 ◽  
Keyword(s):  
Three Dimensional ◽  
Optical Microscope ◽  
Preferred Orientation ◽  
Distribution Functions ◽  
Thin Sections ◽  
Clay Particles ◽  
Degree Of Orientation ◽  
Dimensional Distribution ◽  
Optical Determination

Although single clay particles can seldom be seen with an optical microscope the preferred orientation of an aggregate of clay particles may be investigated by studying in thin section the birefringence of the aggregate. The techniques of preparing thin sections of clay with a minimum of disturbance of the structure and for measuring the birefringence under crossed nicols are described. It is shown that the birefringence of the aggregate arises solely from the birefringence of the constituent particles at least for the porosities of the clay used in this study. If a model distribution function for the spatial orientation of the particles be adopted the birefringent behaviour of the aggregate may be predicted and birefringence observations may be used to interpret the degree of orientation of an aggregate in terms of a model parameter. Two- and three-dimensional distribution functions are considered and the two-dimensional theory is judged to be preferable.

The optical determination of preferred orientation in clays and its application to the study of microstructure in consolidated kaolin. ІІ

1967 ◽  
Vol 300 (1461) ◽  
pp. 235-250 ◽  
Keyword(s):  
Preferred Orientation ◽  
Optical Data ◽  
Initial Structure ◽  
Clay Particles ◽  
One Dimensional ◽  
History Of ◽  
Optical Determination ◽  
The Individual ◽  
Water Contents

The degree of preferred orientation and fabric homogeneity of a clay depend upon its method of preparation and subsequent history of loading. The degree of preferred orientation can be determined by measuring the birefringence ratio for a thin section of clay. When the fabric is homogeneous this value is shown to be independent of the area observed. For a fabric composed of packets containing oriented clay particles a representative value of birefringence ratio for the bulk clay may be obtained by measuring over an area large in comparison with the size of the individual packet. In order to study the development of preferred orientation in a kaolin subject to one-dimensional consolidation, birefringence ratio measurements have been obtained for specimens prepared by sedimentation with both a flocculating and deflocculating pore fluid. Significant differences were observed in the initial structure. When loaded beyond 0.1 ton / ft. 2 the optical data indicated little difference in the preferred orientation of these clays. This was corroborated by the near identity of both compressibility and permeability at particular pressures beyond this level. The birefringence ratio measurements show that for flocculated kaolin prepared by sedimentation the development of intense orientation in this test is virtually complete at a stress level of 0-1 ton /ft. 2 . Microscopic observations of the initial structure of kaolin remoulded at different water contents and with different pore fluids revealed the presence of packets composed of parallel particles. The consolidation of these clays was studied and shown to be strongly influenced by the mobility of these packets. Reconsolidation parallel to the direction of preferred orientation does not materially alter the fabric for the range of stresses considered here.

The petrology of the Mount Padbury mesosiderite and its achondrite enclaves

1966 ◽  
Vol 36 (276) ◽  
pp. 1029-1060 ◽  
Author(s):  
G. J. H. McCall
Keyword(s):  
Microscopic Analysis ◽  
Host Material ◽  
Refractive Indices ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Wide Range ◽  
Varied Range ◽  
Optical Determination

SummaryThe petrography of the Mount Padbury meteorite, previously briefly recorded, is described in some detail. Both the metalliferous host material of the mesosiderite and the varied range of silicate-rich, virtually metal-free enclaves (including both familiar achondrite material and unfamiliar achondrite material) are described. Eucrite, brecciated eucrite, and a peculiar ‘shocked’ form of eucrite (resembling some terrestrial flaser-gabbros) are the calcium-rich achondrite types represented; hypersthene achondrite (including typical diogenite material and unfamiliar material) and olivine achondrite (granular aggregates of olivine not entirely similar to the unique chassignite and single crystals up to 4 in. in length) are the calcium-poor achondrite types represented. The eucrite displays more or less uniform mineralogy, but the mineral constituents are present in varying proportions, and there is a wide range of textural variations recognized. The silicate grain fragments enclosed in the metallic reticulation to form the mesosiderite host material are, significantly, entirely of minerals seen within the achondrite enclaves—plagioclase, hypersthene, pigeonite, olivine, and tridymite.These results include microscopic analysis of thin sections and polished sections, X-ray diffraction studies, optical determination of refractive indices using mineral grain mounts, and chemical analyses.The wider implications of this new and unique meteorite find are briefly considered.

scholarly journals Optical determination of three-dimensional nanotrack profiles generated by single swift-heavy ion impacts in lithium niobate

2006 ◽  
Vol 89 (7) ◽  
pp. 071923 ◽  
Author(s):  
J. Olivares ◽  
A. García-Navarro ◽  
G. García ◽  
A. Mýndez ◽  
F. Agulló-López
Keyword(s):  
Lithium Niobate ◽  
Three Dimensional ◽  
Heavy Ion ◽  
Swift Heavy Ion ◽  
Optical Determination

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 Three-Dimensional Reconstruction and Morphologic Measurements of Human Embryonic Hearts: A New Diagnostic and Quantitative Method Applicable to Fetuses Younger than 13 Weeks of Gestation

2005 ◽  
Vol 8 (4) ◽  
pp. 463-473 ◽  
Author(s):  
Jean-Marc Schleich ◽  
Jean-Louis Dillenseger ◽  
Laurence Loeuillet ◽  
Jacques-Philippe Moulinoux ◽  
Claude Almange
Keyword(s):  
Cardiac Development ◽  
Three Dimensional ◽  
Optical Microscope ◽  
Cardiac Volume ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
First Results ◽  
Made In

Improvements in the diagnosis of congenital malformations explain the increasing early termination of pregnancies. Before 13 weeks of gestation, an accurate in vivo anatomic diagnosis cannot currently be made in all fetuses with current imaging instrumentation. Anatomopathologic examinations remain the gold standard to make accurate diagnoses, although they reach limits between 9 and 13 weeks of gestation. We present the first results of a methodology that can be applied routinely, using standard histologic section, thus enabling the reconstruction, visual estimate, and quantitative analysis of 13-week human embryonic cardiac structures. The cardiac blocks were fixed, embedded in paraffin, and entirely sliced by a microtome. One of 10 slices was topographically colored and digitized on an optical microscope. Cardiac volume was recovered by semiautomatic realignment of the sections. Another semiautomatic procedure allowed extracting and labeling of cardiac structures from the volume. Structures were studied with display tools, which disclosed the internal and external cardiac components and enabled determination of size, thickness, and precise positioning of ventricles, atria, and large vessels. This pilot study confirmed that a new 3-dimensional reconstruction and visualization method enables accurate diagnoses, including in embryos younger than 13 weeks. Its implementation at earlier stages of embryogenesis will provide a clearer view of cardiac development.

scholarly journals Analytic determination of the three-dimensional distribution of dislocations using synchrotron X-ray topography

2006 ◽  
Vol 39 (1) ◽  
pp. 106-108 ◽  
Author(s):  
J. M. Yi ◽  
Y. S. Chu ◽  
T. S. Argunova ◽  
J. H. Je
Keyword(s):  
Three Dimensional ◽  
Analytic Formula ◽  
Detector Plane ◽  
X Ray ◽  
Dimensional Distribution ◽  
Distribution Of Dislocations ◽  
Symmetric Reflection ◽  
Si Wafer

A technique, using a symmetric reflectionviaazimuthal rotation of a sample, is presented for characterization of the three-dimensional distribution of dislocations in single crystals. An analytic formula is derived to transform the three-dimensional geometry of a straight dislocation into its two-dimensional projection onto the detector plane. By fitting topographs to the formula, the orientations and locations of dislocations are quantitatively determined. The dislocations in a thermally stressed Si wafer are examined as an example.

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