Cosmochlore—a new examination

1981 ◽  
Vol 44 (335) ◽  
pp. 265-267 ◽  
Author(s):  
A. G. Couper ◽  
M. H. Hey ◽  
R. Hutchison
Keyword(s):  
Electron Probe ◽  
Optical Data ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Probe Analysis

AbstractExamination of cotype cosmochlore from the Toluca meteorite confirms Laspeyres's observations (1897) in every respect, except that what he determined as iron was largely titanium. His data are completed by an electron-probe analysis and by full optical and X-ray data. Accepting the identity of cosmochlore and ureyite, the optical data of Frondel and Klein (1965) for the latter are partly in error or misprinted.

A note on the occurrence of chevkinite, allanite, and zirkelite on St. Kilda, Scotland

1982 ◽  
Vol 46 (341) ◽  
pp. 445-448 ◽  
Author(s):  
R. R. Harding ◽  
R. J. Merriman ◽  
P. H. A. Nancarrow
Keyword(s):  
Rare Earth ◽  
Great Britain ◽  
Electron Probe ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
Electron Probe Analysis ◽  
Accessory Minerals ◽  
X Ray ◽  
Probe Analysis ◽  
Recorded Occurrence

AbstractThe occurrence of three accessory minerals with significant rare earth contents in Tertiary acid rocks of St. Kilda is described. Allanite, zirkelite, and chevkinite were identified by electron probe analysis (with energy-dispersive attachment) and the chevkinite confirmed by X-ray diffraction. Brief comparison is made with other Tertiary occurrences of RE minerals. This is the first recorded occurrence of chevkinite in Great Britain.

scholarly journals Arsenic-induced bone marrow toxicity: ultrastructural and electron- probe analysis

Blood ◽  
1979 ◽  
Vol 53 (5) ◽  
pp. 820-827 ◽  
Author(s):  
JR Feussner ◽  
JD Shelburne ◽  
S Bredehoeft ◽  
HJ Cohen
Keyword(s):  
Bone Marrow ◽  
Electron Probe ◽  
Megaloblastic Anemia ◽  
Hematologic Toxicity ◽  
Bone Marrow Toxicity ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Arsenic Poisoning ◽  
Probe Analysis ◽  
Local Bone

A patient with severe arsenic poisoning that resulted in marked peripheral blood and bone marrow abnormalities, including megaloblastic erythropoiesis experienced many of the previously reported hematologic complications of arsenic poisoning: leukopenia, granulocytopenia, absolute eosinophilia, and profound anemia. In this study we report an ultrastructural and electron-probe analysis of the bone marrow. Although megaloblastic anemia associated with arsenic poisoning has been described rarely, the presence of arsenic in the local bone marrow milieu has not been demonstrated previously. The ultrastructural features of arsenic-induced bone marrow toxicity are similar to those described in other dyserythropoietic states and include marked nuclear aberrations involving shape, chromatin distribution, and nuclear envelope. Using the technique of energy-dispersive x-ray analysis (electron probe) we demonstrated arsenic in bone marrow spicules; this supports the contention that arsenic can cause megaloblastic anemia. We suggest that this technique may be a useful tool in further studies that attempt to explore the mechanism of arsenic-induced hematologic toxicity. Finally, we suggest that arsenic has a direct toxic effect on DNA synthesis that results in marked disturbances of nuclear division. We recommend that the most appropriate screening procedure to evaluate possible arsenic poisoning is tissue arsenic measurements (hair and nails) rather than 24-hr urinary measurements.

The Siena meteorite: Mineralogy and Chemistry

1969 ◽  
Vol 37 (285) ◽  
pp. 34-44 ◽  
Author(s):  
B. Baldanza ◽  
G. R. Levi-Donati ◽  
H. B. Wiik
Keyword(s):  
Chemical Analysis ◽  
Electron Probe ◽  
Mineralogical Composition ◽  
Ordinary Chondrite ◽  
Optical Data ◽  
Electron Probe Analysis ◽  
Microscopical Analysis ◽  
Probe Analysis ◽  
Composition And Structure ◽  
Good Agreement

SummaryThe principal data are collected about the fall and the distribution of the fragments of the Siena, Italy, meteorite (11·6°E., 43·1°N.). A complete individual, weighing 110·55 g, is described in some detail. Crust morphology, mineralogical composition, and structure were studied. Optical data were established by microscopical analysis and both thin and polished sections were observed. Compared with available electron-probe analysis they are found in good agreement. The chemical analysis is Fe 12·93, Ni 1·39, Co 0·09, FeS 5·46, SiO2 37·10, TiO2 0·14, Al2O3, 3·91 FeO 11·46, MnO 0·35, MgO 23·81, CaO 1·63, Na2O 0·90, K2O 0·16, P2O5 0·44, H2O+ 0·10, H2O− 0·00, Cr2O3 0·56, total 100·43. Siena is an ordinary chondrite, with relatively ambiguous characteristics and evident features of recrystallization and metamorphism.

Methods of Quantitative Electron Probe Analysis*

1963 ◽  
Vol 7 ◽  
pp. 395-418 ◽  
Author(s):  
David B. Wittry
Keyword(s):  
Electron Probe ◽  
Fluorescence Analysis ◽  
Universal Theory ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Calibration Curves ◽  
Probe Analysis ◽  
Quantitative Results ◽  
Relationship Of ◽  
The Relationship

AbstractMethods of quantitative electron probe analysis using empirical working curves have achieved only partial success because of variations in instrument design, analysis conditions, and homogeneity of standards. These problems have been solved for X-ray fluorescence analysis, but many of the more successful empirical methods cannot be used in electron probe analysis; instead, a more theoretical approach is indicated. In electron probe analysis quantitative results can be achieved with only pure elements as standards provided (1) the analysis conditions are carefully selected, (2) the observed intensities can be corrected to obtain the primary intensity actually produced in the specimen, and (3) the relationship of the primary intensity and concentration can be calculated. While present methods of making some of the corrections required improvement and a “universal” theory for relating the primary X-ray intensities to the concentrations still does not exist, the success achieved with this approach indicates that it should be used to the fullest extent before resorting to calibration curves. Moreover, as information is accumulated, the number of cases requiring the use of calibration curves should diminish, so that eventually it may be possible to perform quantitative analysis in any system with only pure elements as standards,

Plumbian tennantite from Sark, Channel Islands

1977 ◽  
Vol 41 (317) ◽  
pp. 59-63 ◽  
Author(s):  
A. C. Bishop ◽  
A. J. Criddle ◽  
A. M. Clark
Keyword(s):  
Powder Diffraction ◽  
Electron Probe ◽  
Visible Spectrum ◽  
Channel Islands ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Probe Analysis ◽  
Cell Dimensions ◽  
Reflectance Data

SummaryAn unusual tennantite, containing 4·64% Pb, has been found on a mineral specimen from Sark's Hope Mine collected in 1843. An electron-probe analysis is given, together with visible spectrum reflectance data, quantitative colour values, VHN, and cell dimensions determined from X-ray powder diffraction photographs.

scholarly journals ELECTRON MICROSCOPY AND ELECTRON PROBE ANALYSIS OF MITOCHONDRIAL CATION ACCUMULATION IN SMOOTH MUSCLE

1974 ◽  
Vol 61 (3) ◽  
pp. 723-742 ◽  
Author(s):  
A. P. Somlyo ◽  
A. V. Somlyo ◽  
C. E. Devine ◽  
P. D. Peters ◽  
T. A. Hall
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Vascular Smooth Muscle ◽  
Electron Probe ◽  
Average Distance ◽  
Main Pulmonary Artery ◽  
Mitochondrial Swelling ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Probe Analysis

The contractile responses to barium and the ultrastructure and ionic composition of mitochondria were studied in vascular smooth muscle. In normal rabbit portal anterior mesenteric vein (PAMV) and main pulmonary artery (MPA) smooth muscle mitochondria were frequently associated with the surface vesicles. The average distance between the outer mitochondrial and inner surface vesicle membrane was 4–5 nm. Ba contractures of MPA were tonic and of PAMV were phasic. Incubation of MPA and PAMV with Ba resulted in the accumulation of mitochondrial granules, followed in the MPA by massive mitochondrial swelling. Oligomycin and anoxia inhibited the appearance of mitochondrial electron-opaque granules and prevented the Ba-induced mitochondrial swelling in the MPA. Electron probe analysis of mitochondria in PAMV incubated with Ba and containing granules showed characteristic Ba signals over the mitochondria. Electron probe X-ray microanalysis also showed a highly significant (P < 0.001) correlation of P with mitochondrial Ba, in an estimated elemental ratio of approximately 3 Ba/4 P. Mitochondrial granules were still prominent after block staining of the osmium-fixed, Ba-loaded PAMV, but electron probe microanalysis showed no Ba, but only U, emissions. Tissues incubated with strontium had electron-opaque mitochondrial granules and deposits in the sarcoplasmic reticulum. X-ray microanalysis of mitochondria containing granules showed the presence of characteristic Sr and Ca emissions. The presence of Sr was similarly verified in the sarcoplasmic reticulum. These findings indicate the energy dependent uptake of divalent cations, in association with phosphate, by mitochondria in vascular smooth muscle in situ and the possibility that mitochondria may contribute to the regulation of intracellular divalent cation levels in smooth muscle.

Wairauite—a new cobalt-iron mineral

1964 ◽  
Vol 33 (266) ◽  
pp. 942-948 ◽  
Author(s):  
G. A. Challis ◽  
J. V. P. Long
Keyword(s):  
New Zealand ◽  
Electron Probe ◽  
Nickel Content ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Iron Mineral ◽  
Probe Analysis ◽  
Cscl Type ◽  
Cobalt Iron ◽  
Small Grains

SummaryA new cobalt-iron mineral of composition close to CoFe has been found associated with awaruite (Ni3Fe) in the Red Hills serpentinites of the Wairau Valley, South Island, New Zealand. The name wairauite, after this locality, is proposed. Electron-probe analysis of the small grains so far discovered has shown that the nickel content is very low (0·5 ± 0·1 wt. %). Wairauite is optically very similar to awaruite but a tendency to form euhedral grains (octahedron and cube) and a slightly lower refiectivity are an aid to identification. No X-ray data are available at present, but it is suggested that the structure may correspond to that of the ordered CsCl type of the synthetic alloy of the same composition.

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