On a simple, stable and efficient bond model for inter-particle adhesion

Author(s):  
Eduardo M. B. Campello ◽  
Osvaldo D. Quintana-Ruiz
Keyword(s):  
Author(s):  
Christopher Antony Ramsden ◽  
Wojciech Piotr Oziminski

AbstractBased on structures determined by X-ray crystallography, ab initio MP2 calculations on type A mesoionic rings give geometries in good agreement with observed values. A study of four mesoionic ring systems, each with exocyclic oxygen, nitrogen or carbon groups, shows that the presence and configuration of exocyclic lone pairs significantly influences the geometry and configurational preference. Using a localised bond model and NBO analysis, these effects are rationalised in terms of an anomeric interaction of lone pairs with the antibonding orbitals of adjacent σ bonds. In agreement with experiment, similar effects are calculated for pyran-2-imines.


1977 ◽  
Vol 55 (11) ◽  
pp. 1930-1936 ◽  
Author(s):  
Melvin Cutler

Recent work has provided independent information about the behavior of the hole concentration c in TlxTe1−x as a function of temperature T and composition x in the range 0.2 ≤ x ≤ 0.6. This makes possible a critical reexamination of a molecular bond model for the structure of the alloy, in which holes are generated by broken Te—Te bonds. The earlier theory is revised to formulate an unrestricted independent bond model (ibm), for which the equations are simple and have obvious physical interpretations. This provides a good description of c(T) but only a qualitatively correct c(x). Using a Thomas–Fermi model for the screening interaction between holes and the acceptor ions, it is shown that the equilibrium constant can be expected to increase rapidly with c at large enough values. A modification in which the free energy of a dangling bond is decreased by proximity to a Tl—Te bond is found to significantly improve the result for c(x). The thermochemical behavior is derived. The entropy of mixing is in fair agreement with experiment, but the enthalpy of mixing is grossly wrong. This reflects the neglect of intermolecular interactions in the theory, which, it seems, can easily account for the remaining discrepancies in the predicted behavior of c.


2014 ◽  
Vol 186 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Naphtali M. Mokgalapa ◽  
Tushar K. Ghosh ◽  
Sudarshan K. Loyalka

2012 ◽  
Vol 329 ◽  
pp. 81-0
Author(s):  
Amitava Ghorai

A Brief Sketch of Different Models for the Calculation of Defect Parameters in Metals and Alloys, Comparison of Data and Limitations Has Been Reviewed here; Especially Relaxations due to a Vacancy Type of Point Defect, its Formation, Migration, Activation Energies and Related other Parameters Based upon the Present Experimental Status. the Models Reviewed Are the Bond Model, Continuum Model, Semi-Discrete Model, Jellium Model, Thermodynamic Model, Lattice Statics Model, Atomistic Continuum Model and Pseudopotential Model. the Main Thrust Concerns the Last Model. the Taylor, Vashishta and Singwi, Harrison, Kleinmann and King and Kutler Form of Exchange and Correlation Function Are Almost Similar, Give Moderate Results and May Be Trusted for Better Results.


1995 ◽  
Vol 51 (1-4) ◽  
pp. 49-69 ◽  
Author(s):  
D. J. Quesnel ◽  
D. S. Rimai ◽  
L. P. Demejo

2011 ◽  
Vol 181-182 ◽  
pp. 366-371
Author(s):  
Hui Liu ◽  
Yan Qiang Li

The micro particle brings much harm to some industrials, agriculture and human activities. The mechanical models of micro particle adhesion to the surface and the control, disposal technology have become very important for prevention from particle aggradations. For the sake of deeply comprehending and researching the adhesion mechanism as well as kinematics characteristic, numerical simulation of particle adhesion was made based on compute simulation package, the analysis of results and relevant comparison demonstrate that it can well simulate actual state and the results of simulation show that the capillary force (Fc) is the biggest, by contrast, the electrostatic force (Fes) is the smallest. Further more, it has some valuable instructions and helpful references for control of micro-particle adhesion to surface. At last, the outlook of issue was put forward.


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