Determination of diffusion rates in acrylamide-based photopolymer material

2006 ◽  
Author(s):  
C. E. Close ◽  
M. R. Gleeson ◽  
J. V. Kelly ◽  
F. T. O'Neill ◽  
D. Mooney ◽  
...  
Keyword(s):  
Diffusion Rates

Pore Structure, Permeability, And Chloride Diffusion In Fly Ash-And Slag-Containing Pastes And Mortars

1988 ◽  
Vol 137 ◽  
Author(s):  
R. I. A. Malek ◽  
D. M. Roy ◽  
Y. Fang
Keyword(s):  
Chloride Diffusion ◽  
Fly Ashes ◽  
Chloride Permeability ◽  
Cement Pastes ◽  
Granulated Blast Furnace Slag ◽  
Transport Of Ions ◽  
Diffusion Rates ◽  
Different Sources ◽  
Limiting Value

AbstractThe transport of ions through cement pastes and mortars with variable contents of fly ashes and granulated blast-furnace slag from different sources and with variable composition has been investigated. The research included the determination of chloride diffusion rate and chloride permeability in relation to microstructure development. The median pore size generally was much diminished in mature blended material compared with Portland cement (PC) pastes and mortars. It appears that, at the same age, a finer microstructure is generally developed in blended specimens compared to PC specimens. Also, it was found that the microstructure approaches a limiting value at longer ages of hydration. That limiting value may be reached at earlier ages with the blends. The chloride diffusion rates and permeabilities in the blends were significantly lower than PC mixes. A comparison between the blends containing fly ashes and those containing slag was made.

scholarly journals Ultrahigh field MRI determination of water diffusion rates in ex vivo human lenses of different age

2021 ◽  
Vol 11 (7) ◽  
pp. 3029-3041
Author(s):  
Thomas Stahnke ◽  
Tobias Lindner ◽  
Rudolf Guthoff ◽  
Oliver Stachs ◽  
Andreas Wree ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Water Diffusion ◽  
Ultrahigh Field ◽  
Ultrahigh Field Mri ◽  
Human Lenses ◽  
Diffusion Rates

Determination of diffusion rates in α-Ti by Heavy Ion Rutherford Backscattering

1992 ◽  
Vol 186 (2) ◽  
pp. 206-208 ◽  
Author(s):  
R.A. Perez ◽  
F. Dyment ◽  
D. Abriola ◽  
G.García Bermudez ◽  
H. Somacal
Keyword(s):  
Heavy Ion ◽  
Rutherford Backscattering ◽  
Diffusion Rates

scholarly journals An X-ray Optical Method for the Determination of Diffusion Properties in Very Thin Bimetallic Films

1975 ◽  
Vol 30 (12) ◽  
pp. 1648-1654
Author(s):  
A. Wagendristel
Keyword(s):  
Alloy Formation ◽  
Experimental Check ◽  
X Ray ◽  
Enhanced Diffusion ◽  
Diffusion Parameters ◽  
Diffusion Rates ◽  
Bimetallic Films ◽  
Good Agreement ◽  
Diffusion Properties

Abstract The change of x-ray optical properties during diffusional alloy formation can be used for the evaluation of diffusion parameters in bimetallic thin film couples. The most pronounced phenomenon governed by these properties are the known Kiessig interferences which can be observed in the specular scattered x-ray beam at very small glancing angles. From these interference patterns diffusion data can be obtained by a comparison with calculated reflection curves based on a proper model for diffusion.The most useful thickness range for this method is below 1000 Å, where common x-ray techniques lose their applicability. Since the changes in the interference patterns are most significant in the early diffusion stages, this technique is most suitable for observing initial interdiffusion, which very often occurs with enhanced diffusion rates.The experimental check of the method is performed in the Au-Ag system. Bimetallic films of the pure components were annealed at temperatures between 200 and 300 °C. In this temperature range diffusion parameters from 10-16 to 10-14 cm2/s were found in good agreement with values obtained by other techniques.

scholarly journals Experimental determination of intragranular helium diffusion rates in boron carbide (B4C)

2019 ◽  
Vol 527 ◽  
pp. 151834 ◽  
Author(s):  
Denis Horlait ◽  
Dominique Gosset ◽  
Aurélien Jankowiak ◽  
Vianney Motte ◽  
Nicolas Lochet ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Experimental Determination ◽  
Diffusion Rates ◽  
Boron Carbide B4c ◽  
Helium Diffusion

SUSTAINED RELEASE HORMONAL PREPARATIONS

1970 ◽  
Vol 63 (1) ◽  
pp. 29-38 ◽  
Author(s):  
G. Benagiano ◽  
M. Ermini ◽  
C. C. Chang ◽  
K. Sundaram ◽  
Fred A. Kind
Keyword(s):  
Sustained Release ◽  
Radioactive Material ◽  
Diffusion Rates

ABSTRACT Determination of radioactivity in urine and faeces was used to monitor absorption of labelled 6-methyl-17α-acetoxypregna-4,6-diene-3,20-dione from polydimethylsiloxane implants. Based on previously determined in vitro diffusion rates, mean absorption was 60% in hamsters, 80% in rabbits, and 85% in rats during the first month after implantation. Thereafter, excretion of radioactive material has slowly decreased. After six months, the rate declined to 40% of the original value.

Gas Movements in the Roots of Avicennia marina (Forsk.) Vierh

1985 ◽  
Vol 12 (2) ◽  
pp. 97 ◽  
Author(s):  
M Curran
Keyword(s):  
Root System ◽  
Oxygen Transport ◽  
Oxygen Diffusion ◽  
Close Agreement ◽  
Avicennia Marina ◽  
Structural Studies ◽  
Epiphytic Algae ◽  
Diffusion Rates ◽  
Selection Of

Apparatus for the determination of the rates of oxygen diffusion through excised portions of the root system of Avicennia marina is described. The diffusive resistances of portions of the horizontal root system are measured and the results compared with the values predicted by simple formulations of Fick's first law of diffusion. Predictions of oxygen diffusion rates made without making allowance for respiration or tortuosity are in close agreement with the measured values and thus it is concluded that the horizontal root system is a highly efficient means of oxygen transport. The diffusive resistances of a selection of pneumatophores are also measured and the effect of epiphytic algae is assessed. Structural studies of both horizontal roots and pneumatophores help to explain the ease with which gas moves within the root system, which is compared in conceptual terms with a series of open tubes.

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