An Edge Dislocation in a Three-Phase Composite Cylinder Model

1991 ◽  
Vol 58 (1) ◽  
pp. 75-86 ◽  
Author(s):  
H. A. Luo ◽  
Y. Chen
Keyword(s):  
Edge Dislocation ◽  
Stable Equilibrium ◽  
Phase Model ◽  
Composite Cylinder ◽  
Two Phase ◽  
Trapping Mechanism ◽  
Three Phase ◽  
Cylinder Model ◽  
Stable Equilibrium Position ◽  
The Stability

An exact solution is given for the stress field due to an edge dislocation embedded in a three-phase composite cylinder. The force on the dislocation is then derived, from which a set of simple approximate formulae is also suggested. It is shown that, in comparison with the two-phase model adopted by Dundurs and Mura (1964), the three-phase model allows the dislocation to have a stable equilibrium position under much less stringent combinations of the material constants. As a result, the so-called trapping mechanism of dislocations is more likely to take place in the three-phase model. Also, the analysis and calculation show that in the three-phase model the orientation of Burgers vector has only limited influence on the stability of dislocation. This behavior is pronouncedly different from that predicted by the two-phase model.

An Edge Dislocation in a Three-Phase Composite Cylinder Model With a Sliding Interface

2002 ◽  
Vol 69 (4) ◽  
pp. 527-538 ◽  
Author(s):  
X. Wang ◽  
Y.-p. Shen
Keyword(s):  
Edge Dislocation ◽  
Arbitrary Point ◽  
Circular Inclusion ◽  
Composite Cylinder ◽  
Phase Form ◽  
Sliding Interface ◽  
Three Phase ◽  
Cylinder Model ◽  
The Matrix ◽  
Perfect Interface

An exact elastic solution is derived in a decoupled manner for the interaction problem between an edge dislocation and a three-phase circular inclusion with circumferentially homogeneous sliding interface. In the three-phase composite cylinder model, the inner inclusion and the intermediate matrix phase form a circumferentially homogeneous sliding interface, while the matrix and the outer composite phase form a perfect interface. An edge dislocation acts at an arbitrary point in the intermediate matrix. This three-phase cylinder model can simultaneously take into account the damage taking place in the circumferential direction at the inclusion-matrix interface and the interaction effect between the inclusions. As an application, we then investigate a crack interacting with the slipping interface.

Transport of organochlorine pesticides in soil columns enhanced by dissolved organic carbon

1997 ◽  
Vol 35 (7) ◽  
pp. 139-145 ◽  
Author(s):  
Jiann-Yuan Ding ◽  
Shian-Chee Wu
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Organochlorine Pesticides ◽  
Transport Model ◽  
Phase Model ◽  
Soil Columns ◽  
Two Phase ◽  
Three Phase ◽  
Phase Transport ◽  
Remediation Of Soil

The objective of this study is to quantify the effects of humic acid solution infiltration on the transport of organochlorine pesticides (OCPs) in soil columns using a three-phase transport model. From experimental results, it is found that the dissolved organic carbon enhances the transport of OCPs in the soil columns. In the OCPs-only column, the concentration profiles of OCPs can be simulated well using a two-phase transport model with numerical method or analytical solution. In the OCPs-DOC column, the migrations of aldrin, DDT and its daughter compounds are faster than those in the OCPs-only column. The simulation with the three-phase model is more accurate than that with the two-phase model. In addition, significant decrease of the fluid pore velocities of the OCPs-DOC column was found. When DOC leachate is applied for remediation of soil or groundwater pollution, the decrease of mean pore velocities will be a crucial affecting factor.

Screw Dislocations in a Three-Phase Composite Cylinder Model With Interface Stress

2008 ◽  
Vol 75 (4) ◽  
Author(s):  
Q. H. Fang ◽  
Y. W. Liu ◽  
P. H. Wen
Keyword(s):  
Boundary Condition ◽  
Classical Case ◽  
Interface Stress ◽  
Composite Cylinder ◽  
Screw Dislocations ◽  
Three Phase ◽  
Cylinder Model ◽  
The Matrix ◽  
Stress Boundary Condition ◽  
Stress Boundary

A three-phase composite cylinder model is utilized to study the interaction between screw dislocations and nanoscale inclusions. The stress boundary condition at the interface between nanoscale inclusion and the matrix is modified by incorporating surface/interface stress. The explicit solution to this problem is derived by means of the complex variable method. The explicit expressions of image forces exerted on screw dislocations are obtained. The mobility and the equilibrium positions of the dislocation near one of the inclusions are discussed. The results show that, compared to the classical solution (without interface stress), more equilibrium positions of the screw dislocation may be available when the dislocation is close to the nanoscale inclusion due to consider interface stress. Also, the mobility of the dislocation in the matrix will become more complex than the classical case.

On the Equilibrium of Cavitation Nuclei in Liquid-Gas Solutions

1981 ◽  
Vol 103 (3) ◽  
pp. 425-430 ◽  
Author(s):  
Y. S. Cha
Keyword(s):  
Stable Equilibrium ◽  
Thermodynamic Theory ◽  
Phase System ◽  
Saturated Liquid ◽  
Theoretical Justification ◽  
Two Phase ◽  
System Pressure ◽  
Two Component ◽  
Cavitation Nuclei ◽  
The Stability

The stability of a spherical bubble in a two-component two-phase system is examined by employing the thermodynamic theory of dilute solutions. It is shown that a bubble can remain in a state of stable equilibrium provided that the ratio of the total number of moles of the solute to the total number of moles of the solvent in the system is not extremely small and that the system pressure falls between an upper bound (dissolution limit) and a lower bound (cavitation limit). The results of the analysis provide a theoretical basis for the persistence of microbubbles in a saturated liquid-gas solution. Thus to a certain extent, the results also help to resolve the dilemma that exists in the field of cavitation due to (1) the necessity of postulating the existence of microbubbles; and (2) the lack of theoretical justification for the persistence of such bubbles in a liquid.

scholarly journals Development of LDPE Crystallinity in LDPE/Cu Composites

2021 ◽  
Author(s):  
Makki Abdelmouleh ◽  
Ilyes Jedidi
Keyword(s):  
Phase Change Materials ◽  
Research Work ◽  
Orthorhombic Phase ◽  
Copper Particle ◽  
Phase Model ◽  
Spectral Simulation ◽  
Two Phase ◽  
Cu Films ◽  
Three Phase

This chapter summarizes the study of the filler (ie copper) effect on LDPE phasic composition in LDPE/Cu composites prepared in solution. During this research work, a particular effort is focused on the use of DSC under non-standard conditions. Therewith, the presence of copper microparticles has a great effect on the network phase than on the crystalline long-range-order phase of LDPE structure. Furthermore, LDPE phasic composition in absence and presence of copper microparticles is investigated by FTIR spectroscopy followed by a spectral simulation of the band that appeared at 720 cm−1 corresponding to the CH2. Anywise, the two-phase model confirmed that no variation is observed of LDPE phase composition for all copper contents into LDPE/Cu films. However, with the three-phase model the orthorhombic phase fraction was found to be constant compared to the fraction of amorphous and that of network phase were found to increase and decrease respectively with increase in the copper particle load in the film. Overall, the thermal and structural behavior of LDPE in presence of copper particles allows this type to be used as phase change materials (PCMs) by adding a paraffin fraction in the LDPE/Cu composite. An update of the most relevant work carried out in the field of phasic characterization of polyethylene is presented in this chapter.

scholarly journals Analysis of a two-phase model describing the growth of solid tumors

2012 ◽  
Vol 24 (1) ◽  
pp. 25-48 ◽  
Author(s):  
JOACHIM ESCHER ◽  
ANCA-VOICHITA MATIOC
Keyword(s):  
Solid Tumors ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Phase Model ◽  
Biophysical Parameters ◽  
Two Phase ◽  
The Stability ◽  
Cell To Cell Adhesion ◽  
Steady State Solutions ◽  
Well Posed

In this paper we consider a two-phase model describing the growth of avascular solid tumors when taking into account the effects of cell-to-cell adhesion and taxis due to nutrient. The tumor is surrounded by healthy tissue which is the source of nutrient for tumor cells. In a three-dimensional context, we prove that the mathematical formulation corresponds to a well-posed problem, and find radially symmetric steady-state solutions of the problem. They appear in the regime where the rate of cell apoptosis to cell proliferation is less than the far field nutrient concentration. Furthermore, we study the stability properties of those radially symmetric equilibria and find, depending on the biophysical parameters involved in the problem, both stable and unstable regimes for tumor growth.

A two-phase model for determining the stability constants for interactions between copper and alginic acid

1990 ◽  
Vol 94 (1) ◽  
pp. 482-488 ◽  
Author(s):  
L. K. Jang ◽  
N. Harpt ◽  
D. Grasmick ◽  
L. N. Vuong ◽  
G. Geesey
Keyword(s):  
Stability Constants ◽  
Alginic Acid ◽  
Phase Model ◽  
Two Phase ◽  
The Stability

scholarly journals The three-phase astrochemical code: modeling of the molecular cloud composition

2021 ◽  
Author(s):  
E. V. Borshcheva ◽  
Keyword(s):  
Observational Data ◽  
Molecular Cloud ◽  
Phase Model ◽  
Chemical Compositions ◽  
Two Phase ◽  
Ice Surface ◽  
Three Phase ◽  
Phase Models ◽  
Dust Surface ◽  
Good Agreement

We describe the implementation of a three-phase astrochemical model (gas + ice surface + bulk) based on the two-phase Presta code (gas + dust surface) and provide results for calculating the molecular cloud composition. The two- and three-phase models produce significantly different chemical compositions. In particular, CO ice abundance in the three-phase model shows good agreement with the observational data, unlike the two-phase model.

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