A sequential radiochemical procedure for isotopic analysis of uranium and thorium in soil

1992 ◽  
Vol 157 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Bahman Parsa
Keyword(s):  
Isotopic Analysis ◽  
Radiochemical Procedure

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

ISOTOPIC ANALYSIS OF SEDIMENTS AS A PROXY FOR ENVIRONMENTAL QUALITY IN TEMPERATE LAKES OF WISCONSIN

2017 ◽  
Author(s):  
John Dannehl ◽  
◽  
Jill Leonard-Pingel ◽  
Andrew Michelson ◽  
Emily Falls
Keyword(s):  
Environmental Quality ◽  
Isotopic Analysis ◽  
Temperate Lakes
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