Temperature dependence of the slowing down and diffusion constants of neutrons in Beryllium oxide

1957 ◽  
Vol 45 (4) ◽  
pp. 224-230 ◽  
Author(s):  
S. B. D. Iyengar ◽  
G. S. Mani ◽  
R. Ramanna ◽  
N. Umakanth
Keyword(s):  
Temperature Dependence ◽  
Beryllium Oxide ◽  
Slowing Down ◽  
Diffusion Constants ◽  
And Diffusion

Slowing down and diffusion of neutrons in Beryllium oxide

1957 ◽  
Vol 45 (4) ◽  
pp. 215-223 ◽  
Author(s):  
S. B. D. Iyengar ◽  
G. S. Mani ◽  
R. Ramanna ◽  
N. Umakanth
Keyword(s):  
Beryllium Oxide ◽  
Slowing Down ◽  
And Diffusion

ULTRACENTRIFUGE AND DIFFUSION STUDIES ON GLUTEN

1942 ◽  
Vol 20c (3) ◽  
pp. 130-159 ◽  
Author(s):  
A. G. McCalla ◽  
Nils Gralén
Keyword(s):  
Sodium Salicylate ◽  
Minimum Weight ◽  
Average Molecular Weight ◽  
Sedimentation Equilibrium ◽  
Velocity Sedimentation ◽  
Molecular Characteristics ◽  
Weight Average Molecular Weight ◽  
Diffusion Constants ◽  
Diffusion Studies ◽  
And Diffusion

The molecular characteristics of gluten in sodium salicylate solutions were studied by means of sedimentation velocity, sedimentation equilibrium, and diffusion measurements. The proportion of total gluten protein molecularly dispersed increased with increase in concentration of sodium salicylate up to 12%, but the dispersed portions had essentially the same sedimentation constant (2.5 ± 0.15) regardless of the concentration of the dispersing medium.The most soluble 25 per cent of the gluten was all molecularly dispersed, but was definitely inhomogeneous. The weight-average molecular weight of this fraction was 44,000, but there is reason to believe the minimum weight may be about 35,000. None of the other fractions was entirely molecularly dispersed, the proportion decreasing with decreasing solubility of the fractions. Aggregates of many sizes existed in all of these fractions, but only the most insoluble contained aggregates large enough to cause opacity. Sedimentation constants of the molecularly dispersed portions increased slightly with decreasing solubility, while diffusion constants decreased markedly. None of the fractions yielded normal curves (diffusion diagrams) but the more soluble the fraction, the more nearly normal the curve. The inhomogeneity responsible for the varying rates of diffusion was due partly to differences in proportion and properties of the molecularly dispersed gluten and partly to aggregates.All properties showed progressive changes both within and between the arbitrarily produced fractions. These results, therefore, support the hypothesis that gluten is a protein system showing progressive and regular changes in properties with change in solubility.

Diffusion of Ce-Al Melts Measured by Sliding Cell Technique

2017 ◽  
Vol 898 ◽  
pp. 679-683
Author(s):  
Cheng Chen ◽  
Jin Liang Hu ◽  
Lang Xiang Zhong ◽  
Bo Zhang
Keyword(s):  
Activation Energy ◽  
Temperature Dependence ◽  
Strong Interaction ◽  
Al Alloy ◽  
Diffusion Behavior ◽  
Diffusion Constants

The diffusion behavior of Ce-Al alloy melt at three temperatures of 943K, 953K and 963K was investigated by sliding shear method. The inter-diffusion constants D show Arrhenius-type temperature dependence in the investigated regimes. Compared with the previous results achieved in Ce-Cu melt, liquid Ce-Al displays a much slower diffusion behavior and rather higher activation energy ED, which was caused by the strong interaction between Ce and Al.

scholarly journals Effects of Local Heating and Premelting in the Terminal Part of the e+ Track

2012 ◽  
Vol 733 ◽  
pp. 15-18 ◽  
Author(s):  
Dmitry Zvezhinskiy ◽  
Sergey V. Stepanov ◽  
Vsevolod Byakov ◽  
Bożena Zgardzińska
Keyword(s):  
Melting Point ◽  
Temperature Dependence ◽  
Local Heating ◽  
Bulk Temperature ◽  
Melting Points ◽  
Terminal Part ◽  
Slowing Down ◽  
Positronium Lifetime ◽  
Molten Region

The terminal part of the e+ track (the positron blob) is formed during ionization slowing down and subsequent ion-electron recombinations produced by a positron. It releases up to 1 keV of energy, which is converted into heat within few picoseconds. If a bulk temperature of a medium is below, but close enough to its melting point, some region of a substance may melt, yielding a peculiar temperature dependence of the lifetime (LT) spectra. We have estimated properties of the molten region with a help of macroscopic heat con- duction equation and suggested a model describing temperature dependence of the ortho- positronium lifetime in frozen methanol, ethanol, butanol and water close to their melting points.

Temperature Dependence of Solvent Swelling and Diffusion Processes in Coals

1997 ◽  
Vol 11 (6) ◽  
pp. 1155-1164 ◽  
Author(s):  
Yoshinobu Otake ◽  
Eric M. Suuberg
Keyword(s):  
Temperature Dependence ◽  
Diffusion Processes ◽  
And Diffusion ◽  
Solvent Swelling

Watching small molecules move: Interrogating ionic channels using neutral solutes

1995 ◽  
Vol 15 (6) ◽  
pp. 503-514 ◽  
Author(s):  
V. A. Parsegian ◽  
S. M. Bezrukov ◽  
I. Vodyanoy
Keyword(s):  
Osmotic Stress ◽  
Ionic Channels ◽  
Ionic Channel ◽  
Water Molecules ◽  
Chemical Potentials ◽  
Diffusion Constants ◽  
Functional States ◽  
Channel Space ◽  
And Diffusion ◽  
Osmotic Activity

Whether they are small enough to wriggle through the current-carrying part of an ionic channel or big enough to be kept outside and thus able to exert an osmotic stress on the channel space, polymers interact with channels in several instructive ways. The osmotic stress of excluded polymers allows one to measure the number of water molecules that come out of the channel in transitions between various “open” to “closed” states. The loss of osmotic activity, due to the partial or completely unrestricted admission of small polymers becomes a measure of the transfer probabilities of polymers from solution to small cavities; it provides an opportunity to study polymer conformation in a perfectly sieved preparation. Current fluctuations due to the partial blockage by a transient polymer are converted into estimates of times of passage and diffusion constants of polymers in channels. These estimates show how a channel whose functional states last for milliseconds is able to average over the interactions with polymers, interactions that last only microseconds. One sees clearly that in this averaging, the macromolecular channel is large enough to react like a macroscopic object to the chemical potentials of the species that modulate its activity.

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