SELF-DIFFUSION IN ICE MONOCRYSTALS.
The self-diffusion of tritium, parallel and perpendicular to the optical axis of naturally occurring and artificially grown ice monocrystals, was studied between -2.5 and -35.9C. The artificial ice monocrystals were grown using a zone-melting technique. Activated samples were stored for several week...
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ftdtic:AD0662196 2023-05-15T16:37:16+02:00 SELF-DIFFUSION IN ICE MONOCRYSTALS. Ramseier,Rene O. COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H 1967-10 text/html http://www.dtic.mil/docs/citations/AD0662196 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0662196 en eng http://www.dtic.mil/docs/citations/AD0662196 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Snow Ice and Permafrost Crystallography (*ICE CRYSTAL STRUCTURE) MOLECULAR STRUCTURE SYMMETRY(CRYSTALLOGRAPHY) CRYSTAL GROWTH DIFFUSION THERMAL PROPERTIES ANISOTROPY TRITIUM THEORY Text 1967 ftdtic 2016-02-18T20:38:06Z The self-diffusion of tritium, parallel and perpendicular to the optical axis of naturally occurring and artificially grown ice monocrystals, was studied between -2.5 and -35.9C. The artificial ice monocrystals were grown using a zone-melting technique. Activated samples were stored for several weeks, then sectioned by microtome and analyzed in a liquid scintillation counter to obtain the self-diffusion coefficients. The plane source solution of Fick's second law was used in treating the data. The diffusion coefficients were found to be identical for both types of ice. A slight anisotropy was found due to the geometry of the crystal; however, the activation energy was found to be 0.62 eV for all cases. Based on the experimental data, it is concluded that the diffusion takes place by a vacancy mechanism and that entire H2O molecules are diffusing, i.e., molecular diffusion occurs. Theoretical calculations using the atomic diffusion theory and Zener's theory for the initial diffusion coefficient are in excellent agreement with the experimentally determined diffusion coefficient. (Author) Text Ice permafrost Defense Technical Information Center: DTIC Technical Reports database |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Snow Ice and Permafrost Crystallography (*ICE CRYSTAL STRUCTURE) MOLECULAR STRUCTURE SYMMETRY(CRYSTALLOGRAPHY) CRYSTAL GROWTH DIFFUSION THERMAL PROPERTIES ANISOTROPY TRITIUM THEORY |
spellingShingle |
Snow Ice and Permafrost Crystallography (*ICE CRYSTAL STRUCTURE) MOLECULAR STRUCTURE SYMMETRY(CRYSTALLOGRAPHY) CRYSTAL GROWTH DIFFUSION THERMAL PROPERTIES ANISOTROPY TRITIUM THEORY Ramseier,Rene O. SELF-DIFFUSION IN ICE MONOCRYSTALS. |
topic_facet |
Snow Ice and Permafrost Crystallography (*ICE CRYSTAL STRUCTURE) MOLECULAR STRUCTURE SYMMETRY(CRYSTALLOGRAPHY) CRYSTAL GROWTH DIFFUSION THERMAL PROPERTIES ANISOTROPY TRITIUM THEORY |
description |
The self-diffusion of tritium, parallel and perpendicular to the optical axis of naturally occurring and artificially grown ice monocrystals, was studied between -2.5 and -35.9C. The artificial ice monocrystals were grown using a zone-melting technique. Activated samples were stored for several weeks, then sectioned by microtome and analyzed in a liquid scintillation counter to obtain the self-diffusion coefficients. The plane source solution of Fick's second law was used in treating the data. The diffusion coefficients were found to be identical for both types of ice. A slight anisotropy was found due to the geometry of the crystal; however, the activation energy was found to be 0.62 eV for all cases. Based on the experimental data, it is concluded that the diffusion takes place by a vacancy mechanism and that entire H2O molecules are diffusing, i.e., molecular diffusion occurs. Theoretical calculations using the atomic diffusion theory and Zener's theory for the initial diffusion coefficient are in excellent agreement with the experimentally determined diffusion coefficient. (Author) |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H |
format |
Text |
author |
Ramseier,Rene O. |
author_facet |
Ramseier,Rene O. |
author_sort |
Ramseier,Rene O. |
title |
SELF-DIFFUSION IN ICE MONOCRYSTALS. |
title_short |
SELF-DIFFUSION IN ICE MONOCRYSTALS. |
title_full |
SELF-DIFFUSION IN ICE MONOCRYSTALS. |
title_fullStr |
SELF-DIFFUSION IN ICE MONOCRYSTALS. |
title_full_unstemmed |
SELF-DIFFUSION IN ICE MONOCRYSTALS. |
title_sort |
self-diffusion in ice monocrystals. |
publishDate |
1967 |
url |
http://www.dtic.mil/docs/citations/AD0662196 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0662196 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/AD0662196 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
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1766027559649148928 |