Engineering topics

Duba, AL

Publications and source records attributed to Duba, AL.

4 records

NASA NTRS1987

Experimental cosmochemistry in the Space Station

The purpose of two workshops was to identify and discuss experiments in cosmochemistry that cannot be conducted under the conditions available in terrestrial laboratories, but may be carried out successfully in the proposed Space Station. The scientific discussions focused on two general areas of research: chemical and physical processes in the earliest history of the general areas of research, and general principles of magmatic process applicable both to planetary formation and evolution, as well as present-day magmatic activity in and on terrestrial planets.

Duba, AL↗

NASA NTRS1987

Report on OTHER proposals for SSPEX

The only unifying factor among the experiments discussed is that they are all unique Opportunities and/or Techniques for High-caliber Experimental Research (OTHER). Thirteen of the experiments are briefly described.

Nuth, Joseph A.↗

NASA NTRS1987

Electrical conductivity of carbonaceous chondrites and electric heating of meteorite parent bodies

Electromagnetic heating of rock-forming materials most probably was an important process in the early history of the solar system. Electrical conductivity experiments of representative materials such as carbonaceous chondrites are necessary to obtain data for use in electromagnetic heating models. With the assumption that carbon was present at grain boundaries in the material that comprised the meteorite parent bodies, the electrical heating of such bodies was calculated as a function of body size and solar distance using the T-Tauri model of Sonett and Herbert (1977). The results are discussed.

Duba, AL↗

NASA NTRS1987

Electrical conductivity of chondritic meteorites

The electrical conductivity of samples of the Murchison and Allende carbonaceous chondrites is 4 to 6 orders of magnitude greater than rock forming minerals such as olivine for temperatures up to 700 C. The remarkably high electrical conductivity of these meteorites is attributed to carbon at the grain boundaries. Much of this carbon is produced by pyrolyzation of hydrocarbons at temperatures in excess of 150 C. As the temperature increases, light hydrocarbons are driven off and a carbon-rich residue or char migrates to the grain boundaries enhancing electrical conductivity. Assuming that carbon was present at the grain boundaries in the material which comprised the meteorite parent bodies, the electrical heating of such bodies was calculated as a function of body size and solar distance during a hypothetical T-Tauri phase of the sun. Input conductivity data for the meteorite parent body were the present carbonaceous chondrite values for temperatures up to 840 C and the electrical conductivity values for olivine above 840 C.

Duba, AL↗