Solidification of a Finite Medium Subject to a Periodic Variation of Boundary Temperature

2003 ◽  
Vol 70 (5) ◽  
pp. 633-637 ◽  
Author(s):  
Z. Dursunkaya ◽  
S. Nair
Keyword(s):  
Infinite Series ◽  
Solution Method ◽  
Periodic Variation ◽  
One Dimensional ◽  
Retrograde Motion ◽  
Boundary Temperature ◽  
Temperature Distributions ◽  
Finite Medium ◽  
Solid Liquid Interface ◽  
Solid Liquid

The motion of a solid-liquid interface in a finite one-dimensional medium, subject to a fluctuating boundary temperature, is analyzed. The fluctuations are assumed to be periodic. The solution method involves a semi-analytic approach in which, at any given time, the spatial temperature distributions are represented in infinite series. The effect of the solid, liquid Stefan numbers and the unsteady boundary temperature variation is investigated. The results showed a retrograde motion of the solidification front for large liquid Stefan numbers.

scholarly journals Approximate Analytical Solution for One-Dimensional Solidification Problem of a Finite Superheating Phase Change Material Including the Effects of Wall and Thermal Contact Resistances

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Hamid El Qarnia ◽  
Fayssal El Adnani ◽  
El Khadir Lakhal
Keyword(s):  
Analytical Solution ◽  
Phase Change ◽  
Phase Change Material ◽  
Liquid Interface ◽  
Solid Shell ◽  
Interface Position ◽  
Temperature Distributions ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

This work reports an analytical solution for the solidification of a superheating phase change material (PCM) contained in a rectangular enclosure with a finite height. The analytical solution has been obtained by solving nondimensional energy equations by using the perturbation method for a small perturbation parameter: the Stefan number,ε. This analytical solution, which takes into account the effects of the superheating of PCM, finite height of the enclosure, thickness of the wall, and wall-solid shell interfacial thermal resistances, was expressed in terms of nondimensional temperature distributions of the bottom wall of the enclosure and both PCM phases, and the dimensionless solid-liquid interface position and its dimensionless speed. The developed solution was firstly compared with that existing in the literature for the case of nonsuperheating PCM. The predicted results agreed well with those published in the literature. Next, a parametric study was carried out in order to study the impacts of the dimensionless control parameters on the dimensionless temperature distributions of the wall, the solid shell, and liquid phase of the PCM, as well as the solid-liquid interface position and its dimensionless speed.

Analysis of In-Flight Oxidation During Reactive Spray Atomization and Deposition Processing of Aluminum

1999 ◽  
Vol 122 (1) ◽  
pp. 126-133 ◽  
Author(s):  
J.-P. Delplanque ◽  
E. J. Lavernia ◽  
R. H. Rangel
Keyword(s):  
Volume Fraction ◽  
Oxide Thickness ◽  
Progression Rate ◽  
Spray Atomization ◽  
One Dimensional ◽  
Spatially Resolved ◽  
Dimensional Equation ◽  
The One ◽  
Solid Liquid Interface ◽  
Solid Liquid

This work defines a model to predict the characteristics of materials processed using reactive spray atomization and deposition. The materials considered are aluminum alloys while target dispersoids are primarily oxides. These may be obtained by the reaction of oxygen-containing atomization gas mixtures with molten alloy droplets. Droplet position and velocity histories are obtained from the numerical solution of the one-dimensional equation of motion. The energy equation inside the droplet is solved numerically using finite differences to predict the spatially resolved temperature field. The solid/liquid interface progression rate is estimated using a power law while an oxidation rate expression based on the Mott-Cabrera theory is used for the oxide thickness. Such a model should prove very valuable in determining the parameters controlling the volume fraction and the size distribution of the dispersoids for various systems. [S0022-1481(00)02901-7]

A TEMPLATE-FREE SOLUTION METHOD BASED ON SOLID-LIQUID INTERFACE REACTION TOWARDS DENDRITIC PbSe NANOSTRUCTURES

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3817-3823 ◽  
Author(s):  
JUN LIU ◽  
DONGFENG XUE
Keyword(s):  
Large Scale ◽  
Solution Method ◽  
Interface Reaction ◽  
Liquid Interface ◽  
Free Solution ◽  
Dendritic Nanostructures ◽  
Template Free ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Solvothermal Conditions

A template-free solution method based on solid-liquid interface reaction has been developed for fabricating metal chalcogenide dendritic nanostructures. Well-defined PbSe dendrites with four branches can be large-scale synthesized with metal lead foil as Pb 2+ source and Na 2 SeO 3 as Se 2+ source in solvothermal conditions. The nanorods in each branch are parallel to each other in the same plane and are perpendicular to the trunk. It was found that PbSe cubes first formed on the lead substrate through a direct surface reaction and that subsequent crystal growth preferentially took place on the vertex of these PbSe cubes, leading to the formation of final branched dendrites. The current solid-liquid interface reaction has been extended to the synthesis of CuS micro-pine dendrites with copper foil and sulfur powder as reaction reagents.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

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