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.

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.

scholarly journals Untersuchungen am System Vanadium—Gallium

1966 ◽  
Vol 21 (5) ◽  
pp. 531-540 ◽  
Author(s):  
R. G. Maier ◽  
Y. Uzel ◽  
H. Kandler
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Electron Probe ◽  
Liquidus Curve ◽  
X Ray Diffraction ◽  
Equilibrium Conditions ◽  
Electron Probe Analysis ◽  
X Ray ◽  
Oxygen System ◽  
Annealing Experiments

The phase diagram of the vanadium-gallium system was investigated by means of thermoanalysis, microscopy, x-ray diffraction, and electron probe analysis.The liquidus curve was measured in the range from 40—80% Gallium. The existence of the known phases V3Ga (Cr3Si-typ), V6Ga5 (Ti6Sn5-typ), V6Ga7 (Cu5Zn8-typ), V2Ga5 (Mn2Hg5-typ), V4GaO and V5Ga3Ox (Mn5Si3-typ) was reestablished. The existence of V3GaOx and V5 (Ga, Si)3Ox is stated and their crystal structure investigated.It is shown that the oxygen content of he samples greatly influences the equilibrium conditions of the system. By means of annealing experiments and dilatometric measurements the phase diagram of the vanadium-gallium-oxygen system was investigated in the range of small oxygen contents.

Extraction of Rare Earth from La–Ni Alloys by the Glass Slag Method

2003 ◽  
Vol 18 (12) ◽  
pp. 2814-2819 ◽  
Author(s):  
Tetsuji Saito ◽  
Hironori Sato ◽  
Tetsuichi Motegi
Keyword(s):  
Rare Earth ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Oxide Phase ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Boron Trioxide ◽  
Ni Alloys

The use of the glass slag method in the extraction of rare earth from La–Ni alloys was studied. X-ray diffraction and electron probe microanalysis studies revealed that the La–Ni alloys produced by the glass slag method using boron trioxide consisted of Ni and Ni3B phases. No La-containing phase such as the LaNi5 phase and the La oxide phase was found in the resultant alloys. The chemical analyses confirmed that the La content in the alloys produced by the glass slag method was very limited. However, the glass slag materials contained a large amount of lanthanum. The La in the La–Ni alloys was successfully extracted by the glass slag method using boron trioxide.

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.

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.

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