DENSITY-FRACTION X-RAY ANALYSIS: A NEW TECHNIQUE OF MODAL ANALYSIS OF ROCKS

1967 ◽  
Vol 4 (6) ◽  
pp. 1093-1117 ◽  
Author(s):  
George Erdosh
Keyword(s):  
Modal Analysis ◽  
Instrumental Method ◽  
Point Counting ◽  
Rock Powder ◽  
X Ray ◽  
Density Fractions ◽  
Rock Types ◽  
Unreliable Method ◽  
A New Technique ◽  
Analytical Time

Point counting, the present and often unreliable method of modal analysis of rocks, is unsatisfactory for many rock types. An instrumental technique that could be routinely performed by a technician is highly desirable. X-ray powder diffraction has been critically evaluated for this purpose and was found to be a suitable instrumental method when combined with density separation. A practical technique is thus proposed in which the rock powder is split into three density fractions by heavy-liquid separations and each fraction is quantitatively analyzed for its major constituents by X-ray diffraction. Altogether 28 minerals are considered, which are constituents of most igneous and many metamorphic rocks, and calibration curves are given for ten of these. With one exception, the precision was found to be reasonably good for the minerals determined. The accuracy of the technique could not be tested satisfactorily. The analytical time varies from 2 to 4 man-hours per sample depending on the rock type. Although the study is somewhat preliminary and the proposed technique is incomplete, it already shows some obvious advantages over point counting for many rock types.

Measurement of the modal composition of a granitic rock powder by point-counting, infra-red spectroscopy, and X-ray diffraction

1967 ◽  
Vol 36 (277) ◽  
pp. 94-100
Author(s):  
P. M. D. Bradshaw
Keyword(s):  
Rapid Method ◽  
Granitic Rock ◽  
Point Counting ◽  
X Ray Diffraction ◽  
Modal Composition ◽  
Rock Powder ◽  
X Ray ◽  
Additional Information ◽  
Infra Red

SummaryA rapid method for determining the mode of a four-component powder (microcline, orthoclase, plagioclase, and quartz) was sought to aid the interpretation of geochemical results. An accuracy of about ±5 % (absolute) was required. Three methods were tried : point counting proved too long as well as destroying the sample; infra-red spectroscopy was not sufficiently accurate for this particular type of rock powder; X-ray diffraction proved the most rapid and, although less accurate than point counting, was within acceptable limits and had the advantage of giving additional information about the composition of the feldspars.

Techniques for cryoultramicrotomy of propane jet frozen biological samples

1986 ◽  
Vol 44 ◽  
pp. 260-261
Author(s):  
B. Craig ◽  
L. Hawkey ◽  
A. LeFurgey
Keyword(s):  
Freeze Fracture ◽  
Freeze Substitution ◽  
Heart Cells ◽  
Crystal Formation ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
A New Technique

Ultra-rapid freezing followed by cryoultramicrotomy is essential for the preservation of diffusible elements in situ within cells prior to scanning transmission electron microscopy and quantitative energy dispersive x-ray microanalysis. For cells or tissue fragments in suspension and for monolayer cell cultures, propane jet freezing provides cooling rates greater than 30,000°C/sec with regions up to 40μm in thickness free of significant ice crystal formation. While this method of freezing has frequently been applied prior to freeze fracture or freeze substitution, it has not been widely utilized prior to cryoultramicrotomy and subsequent x-ray microanalytical studies. This report describes methods devised in our laboratory for cryosectioning of propane jet frozen kidney proximal tubule suspensions and cultured embryonic chick heart cells, in particular a new technique for mounting frozen suspension specimens for sectioning. The techniques utilize the same specimen supports and sample holders as those used for freeze fracture and freeze substitution and should be generally applicable to any cell suspension or culture preparation.

Argon Plasma Induced Surface Modifications For Resistless Patterning Of Aluminium Films

1991 ◽  
Vol 223 ◽  
Author(s):  
Neeta Agrawal ◽  
R. D. Tarey ◽  
K. L. Chopra
Keyword(s):  
Etch Rate ◽  
Argon Plasma ◽  
Surface Modifications ◽  
Surface Chemical ◽  
Plasma Exposure ◽  
X Ray ◽  
Aluminium Fluoride ◽  
A New Technique ◽  
Plasma Exposure Time ◽  
Surface Chemical Modification

ABSTRACTArgon plasma exposure has been used to induce surface chemical modification of aluminium thin films, causing a drastic change in etch rate in standard HNO3/CH3COOH/H3PO4 etchant. The inhibition period was found to increase with power and Ar plasma exposure time. Auger electron and x-ray photoelectron spectroscopies have indicated formation of an aluminium fluoride (AlF3) surface layer due to fluorine contamination originating from the residue left in the plasma chamber during CF4 processing. The high etch selectivity between unexposed and argon plasma exposed regions has been exploited as a new technique for resistless patterning of aluminium.

A new technique for measuring the polarization from celestial X-ray sources

1993 ◽  
Author(s):  
Robert Austin ◽  
Takahisa Minamitani ◽  
Brian Ramsey
Keyword(s):  
New Technique ◽  
X Ray ◽  
A New Technique

scholarly journals Algorithms for 3D Particles Characterization Using X-Ray Microtomography in Proppant Crush Test

2018 ◽  
Vol 4 (11) ◽  
pp. 134 ◽  
Author(s):  
Ilia Safonov ◽  
Ivan Yakimchuk ◽  
Vladimir Abashkin
Keyword(s):  
Laboratory Method ◽  
X Ray ◽  
Geometric Moments ◽  
Before And After ◽  
Statistical Hypotheses ◽  
Image Processing Algorithms ◽  
A New Technique ◽  
Individual Particles ◽  
Remarkable Advantage

We present image processing algorithms for a new technique of ceramic proppant crush resistance characterization. To obtain the images of the proppant material before and after the test we used X-ray microtomography. We propose a watershed-based unsupervised algorithm for segmentation of proppant particles, as well as a set of parameters for the characterization of 3D particle size, shape, and porosity. An effective approach based on central geometric moments is described. The approach is used for calculation of particles’ form factor, compactness, equivalent ellipsoid axes lengths, and lengths of projections to these axes. Obtained grain size distribution and crush resistance fit the results of conventional test measured by sieves. However, our technique has a remarkable advantage over traditional laboratory method since it allows to trace the destruction at the level of individual particles and their fragments; it grants to analyze morphological features of fines. We also provide an example describing how the approach can be used for verification of statistical hypotheses about the correlation between particles’ parameters and their crushing under load.

scholarly journals Pinning down the superfluid and measuring masses using pulsar glitches

2015 ◽  
Vol 1 (9) ◽  
pp. e1500578 ◽  
Author(s):  
Wynn C. G. Ho ◽  
Cristóbal M. Espinoza ◽  
Danai Antonopoulou ◽  
Nils Andersson
Keyword(s):  
Observational Data ◽  
New Technique ◽  
Timing Behavior ◽  
Fundamental Physics ◽  
X Ray ◽  
The Core ◽  
Timing Precision ◽  
A New Technique

Pulsars are known for their superb timing precision, although glitches can interrupt the regular timing behavior when the stars are young. These glitches are thought to be caused by interactions between normal and superfluid matter in the crust of the star. However, glitching pulsars such as Vela have been shown to require a superfluid reservoir that greatly exceeds that available in the crust. We examine a model in which glitches tap the superfluid in the core. We test a variety of theoretical superfluid models against the most recent glitch data and find that only one model can successfully explain up to 45 years of observational data. We develop a new technique for combining radio and x-ray data to measure pulsar masses, thereby demonstrating how current and future telescopes can probe fundamental physics such as superfluidity near nuclear saturation.

scholarly journals The low-mass pre-main sequence population of Scorpius OB1

2018 ◽  
Vol 615 ◽  
pp. A148 ◽  
Author(s):  
Francesco Damiani
Keyword(s):  
Total Mass ◽  
Main Sequence ◽  
Near Infrared ◽  
Large Population ◽  
X Ray ◽  
Uv Excess ◽  
Low Mass ◽  
Ob Associations ◽  
The Rich ◽  
A New Technique

Context. The low-mass members of OB associations, expected to be a major component of their total population, are in most cases poorly studied because of the difficulty of selecting these faint stars in crowded sky regions. Our knowledge of many OB associations relies on only a relatively small number of massive members. Aims. We study here the Sco OB1 association, with the aim of a better characterization of its properties, such as global size and shape, member clusters and their morphology, age and formation history, and total mass. Methods. We use deep optical and near-infrared (NIR) photometry from the VPHAS+ and VVV surveys, over a wide area (2.6° × 2.6°), complemented by Spitzer infrared (IR) data, and Chandra and XMM-Newton X-ray data. A new technique is developed to find clusters of pre-main sequence M-type stars using suitable color-color diagrams, complementing existing selection techniques using narrow-band Hα photometry or NIR and ultraviolet (UV) excesses, and X-ray data. Results. We find a large population of approximately 4000 candidate low-mass Sco OB1 members whose spatial properties correlate well with those of Hα-emission, NIR-excess, UV-excess, and X-ray detected members, and unresolved X-ray emission. The low-mass population is spread among several interconnected subgroups: they coincide with the HII regions G345.45+1.50 and IC4628, and the rich clusters NGC 6231 and Trumpler 24, with an additional subcluster intermediate between these two. The total mass of Sco OB1 is estimated to be ~ 8500 M⊙. Indication of a sequence of star-formation events is found, from South (NGC 6231) to North (G345.45+1.50). We suggest that the diluted appearance of Trumpler 24 indicates that the cluster is now dissolving into the field, and that tidal stripping by NGC 6231 nearby contributes to the process.

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