Climate-Relevant Ocean Transport Measurements in the Atlantic and Arctic Oceans

AbstractThe use of transient photoconductivity techniques in the investigation of carrier transport in microcrystalline silicon is described. Results are presented which highlight variations in transport parameters such as carrier mobility and density of states with structure composition. Hole mobility is significantly enhanced by crystalline content in the film of 10% or less. The density of states inferred from transport measurements parallel to and at right angles to the direction of film growth differ somewhat, suggesting that transport may be anisotropic.

Download Full-text

Transient Water Transport in Nafion Membranes Under Activity Gradients

ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 1 ◽

10.1115/fuelcell2010-33317 ◽

2010 ◽

Author(s):

T. Romero ◽

W. Me´rida

Keyword(s):

Water Content ◽

Water Transport ◽

Water Activity ◽

Thickness Variation ◽

Membrane Thickness ◽

Membrane Interface ◽

Rational Representation ◽

Transport Measurements ◽

Nafion Membranes ◽

The Time Domain

Transient water transport experiments on Nafion of different thicknesses were carried out in the temperature range of 30 to 70 °C. These experiments report on water transport measurements under activity gradients in the time domain for liquid and vapour equilibrated Nafion membranes. Using a permeability test rig with a gated valve, the water crossover was measured as a function of time. The typical response is shown as a time dependent flux, and it shows the dynamic transport from an initially dry condition up to the final steady state. Contrarily to previous reports from dynamic water transport measurements, where the activity gradient across the membrane is absent; in this work, the membrane was subjected to an activity gradient acting as the driving force to transport water from an environment with higher water activity to an environment with lower water activity through the membrane’s structure. Measurements explored temperature and membrane thickness variation effect on the transient response. Results showed dependency on temperature and a slower water transport rate across the vapour-membrane interface than for the liquid-membrane interface. These measurements showed the transport dependency on water content at the beginning of the experiment when the membrane was in a close-to-dry condition suggesting a transport phenomenon transition due to a reached critical water content value. The new protocol for transient measurements proposed here will allow the characterization of water transport dependency on membrane water content with a more rational representation of the membrane-environment interface.

Download Full-text

Comment on the Interpretation of Transport Measurements in PbTe

International Journal of Electronics ◽

10.1080/00207216508937774 ◽

1965 ◽

Vol 18 (4) ◽

pp. 397-398 ◽

Cited By ~ 1

Author(s):

R. S. ALLGAIER

Keyword(s):

Transport Measurements

Download Full-text

Transport in the Al71Pd21Mn8−XReX Quasicrystalline System

Journal of Materials Research ◽

10.1557/jmr.2002.0269 ◽

2002 ◽

Vol 17 (7) ◽

pp. 1814-1819 ◽

Cited By ~ 4

Author(s):

A. L. Pope ◽

T. M. Tritt ◽

R. Gagnon ◽

J. Strom-Olsen ◽

S. Legault ◽

...

Keyword(s):

Electronic Transport ◽

Thermal Transport ◽

X Ray ◽

Transport Measurements

In an effort to understand the effects of a quartenary element introduced into a ternary quasicrystalline system, quartenary Al71Pd21Mn8−XReX quasicrystals were grown, where X had values of 0, 0.08, 0.25, 0.4, 0.8, 2, 5, and 8. X-ray data confirm that the addition of a fourth element does not alter the quasiperiodicity of the sample. Because electronic transport is governed by different mechanisms in the parent systems (Al71Pd21Mn8 and Al71Pd21Re8), electrical and thermal transport measurements in the alloyed system have been performed on these samples and are presented here.

Download Full-text