Influence of the interphasal surface energy on the stability of solid disperse systems

1978 ◽  
Vol 21 (11) ◽  
pp. 1393-1397
Author(s):  
V. I. Psarev
Keyword(s):  
Surface Energy ◽  
Disperse Systems ◽  
Solid Disperse ◽  
The Stability

Dynamic and Stability Analysis of the Rotating Nanobeam in a Nonuniform Magnetic Field Considering the Surface Energy

2016 ◽  
Vol 08 (04) ◽  
pp. 1650048 ◽  
Author(s):  
M. Baghani ◽  
M. Mohammadi ◽  
A. Farajpour
Keyword(s):  
Magnetic Field ◽  
Stability Analysis ◽  
Angular Velocity ◽  
Surface Energy ◽  
Axial Load ◽  
Nonuniform Magnetic Field ◽  
Small Scale ◽  
Stability Behavior ◽  
Compressive Axial Load ◽  
The Stability

It is well-known that rotating nanobeams can have different dynamic and stability responses to various types of loadings. In this research, attention is focused on studying the effects of magnetic field, surface energy and compressive axial load on the dynamic and the stability behavior of the nanobeam. For this purpose, it is assumed that the rotating nanobeam is located in the nonuniform magnetic field and subjected to compressive axial load. The nonlocal elasticity theory and the Gurtin–Murdoch model are applied to consider the effects of inter atomic forces and surface energy effect on the vibration behavior of rotating nanobeam. The vibration frequencies and critical buckling loads of the nanobeam are computed by the differential quadrature method (DQM). Then, the numerical results are testified with those results are presented in the published works and a good correlation is obtained. Finally, the effects of angular velocity, magnetic field, boundary conditions, compressive axial load, small scale parameter and surface elastic constants on the dynamic and the stability behavior of the nanobeam are studied. The results show that the magnetic field, surface energy and the angular velocity have important roles in the dynamic and stability analysis of the nanobeams.

Bulk and (001) Surface Properties of TiAl3 Compound

2011 ◽  
Vol 299-300 ◽  
pp. 417-421
Author(s):  
Li Wang ◽  
Jian Hong Gong ◽  
Jun Gao
Keyword(s):  
Surface Energy ◽  
Structural Relaxation ◽  
Density Functional ◽  
Dominant Role ◽  
Lower Surface ◽  
Heat Of Formation ◽  
Lattice Constants ◽  
Structural And Electronic Properties ◽  
The Stability ◽  
Lower Surface Energy

The structural and electronic properties of bulk and (001) surface of TiAl3 have been examined by the first-principles total-energy pseudopotential method based on density functional theory. The lattice constants and heat of formation of bulk TiAl3 we obtained are in good agreement with the experimental and other theoretical values. The calculated bulk properties indicates that bonding nature in TiAl3 is a combination of metallic and ionic, in which the metallic bonding become the predominate one. the strongest hybridization exist in the DO22 structure, the Al-3p and Ti-3d bonding of TiAl3 play the dominant role in hybridization. The structural relaxation and surface energy for (001) slab have been simulated to make sure the stability of slabs with different atomic layers. Compared to TiB2 (0001) slab, TiAl3 surfaces shows smaller structural relaxation and lower surface energy, furthermore, the charge redistribution of (001) slab shows almost the same characteristics as bulk TiAl3, which confirms structural stability of TiAl3 with (001) slab. This present work makes a beneficial attempt at exploring TiAl3 surface as an ab initio method for studying possible nucleation mechanism of Aluminum on it.

Stability and Electronic Structures of Mg2Pb (100), (110) and (111) Surfaces

2015 ◽  
Vol 817 ◽  
pp. 690-697
Author(s):  
Yong Hua Duan ◽  
Yong Sun ◽  
Ming Jun Peng
Keyword(s):  
Density Functional Theory ◽  
Surface Energy ◽  
Density Of States ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Dft Method ◽  
Functional Theory ◽  
Charge Density Difference ◽  
The Stability

The stability and electronic properties of Mg2Pb (100), (110) and (111) surfaces were investigated by using the first-principles density functional theory (DFT) method. The calculated results showed that the orders of relaxation and surface energy are |∆d15(111)| < |∆d15(110)| < |∆d15(100)| andEsurf(100) >Esurf(110) >Esurf(111), respectively, indicating that Mg2Pb (111) surface is the most stable among these three low index surfaces. The Density of states (DOS) of Mg2Pb surfaces are mainly dominated by Pb-6, Mg-3s, and 2porbitals in the band ranging from-5 eV to Fermi level. It can be further obtained from results of the DOS and the charge density difference that Mg2Pb (111) surface is more stable than Mg2Pb (100) and (110) surfaces. The Mg2Pb (111) surface is the thermodynamically most favorable over all of the range of.

On Protecting and Sensitising Colloidal Sols

1924 ◽  
Vol 22 (2) ◽  
pp. 101-104
Author(s):  
Eric K. Rideal
Keyword(s):  
Isoelectric Point ◽  
Electrokinetic Potential ◽  
Colloidal System ◽  
Disperse Systems ◽  
The Stability

Stable colloidal sols are always charged, and disperse systems in water appear in most cases to acquire a constant electrokinetic potential of 70 m.v. When the electrokinetic potential falls to 30 m.v. coagulation commences and the rate of coagulation is, as Hardy first pointed out, most rapid at the isoelectric point. Thus the question on what the stability of a colloidal system rests must ultimately be referred to the magnitude of the electrokinetic potential and the methods by which this is increased or decreased in solution.

Characterization of acrylic copolymer latex modified by fluorine, silicon, and epoxy resin

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Pingting Xiong ◽  
Rong Guan ◽  
Deping Lu ◽  
Peizhi Chen ◽  
Ling Shen Hongzhi Huang
Keyword(s):  
Surface Energy ◽  
Epoxy Resin ◽  
Acrylic Copolymer ◽  
Force Microscopy ◽  
Acrylic Latex ◽  
Transmission Electron ◽  
Acid And Base ◽  
Acrylic Copolymers ◽  
Increasing Demand ◽  
The Stability

AbstractThe ever-increasing demand of waterborne heavy-duty coatings for high resistance to many aggressive environment factors and low-surface energy has spurred the ongoing development of acrylic latex modified by fluorine, silicon, and epoxy resin. The morphology of the latex particles were characterized by means of light scattering and transmission electron microscopy (TEM). The stability measurements of modified latex and films showed that the resultant acrylic copolymers containing fluorine, silicon and epoxy resin represented very good resistance to organic solvent, acid and base, water and heat. From contact angle measurements and atomic force microscopy (AFM), a dense and gradient film with surface energy as low as 16.1 mN/m was obtained.

scholarly journals Research and analysis of the results from the goniometer and tribotester using the diamond – derivating coating on piston ring

2019 ◽  
Vol 179 (4) ◽  
pp. 147-150
Author(s):  
Joanna BORKOWSKA ◽  
Andrzej KAŹMIERCZAK
Keyword(s):  
Free Surface ◽  
Surface Energy ◽  
Piston Ring ◽  
Friction Pair ◽  
Energy State ◽  
Tangential Force ◽  
Diamond Powder ◽  
Free Surface Energy ◽  
Combustion Engines ◽  
The Stability

The elements creating friction pairs are described to be very difficult in terms of determining all optimal parameters in an unambiguous manner. The nowadays research on stability of friction pairs is focused on the surface and the top layer of surface. The main goal is find new design solutions and materials, achieving a lot of kilometers to main repair in combustion engines. The biggest structural difficulties are noticeable in friction pairs where can be observed sliding and returning motion, what is connected with sealing function. A typical example of such pair is piston ring – cylinder. Engineers work on defining an additional factor that would be able to gain the reduction of tangential force by reducing the friction coefficient in elements of friction pair. Molecular structure and nature of the bonds between the molecules presented in the material, result that the free surface energy may be such a factor, because determines the tribological properties of the material, what is reflected in the stability of the units. The work carries out of an analysis after research on the goniometer in the presence of water and diododomethane that allowed to measure wetting drops on the surface, thanks to which can be calculated surface energy. Within this work will be performed study of the energy state of the surface of piston rings with a coating including a diamond powder. After analysis on the basis of the collected measurements will be developed conclusion regarding the potential relationship between the free surface energy and wearing of the material.

scholarly journals Equilibrium states and stability of pre-tensioned adhesive tapes

2014 ◽  
Vol 5 ◽  
pp. 1725-1731 ◽  
Author(s):  
Carmine Putignano ◽  
Luciano Afferrante ◽  
Luigi Mangialardi ◽  
Giuseppe Carbone
Keyword(s):  
Surface Energy ◽  
Stability Region ◽  
Initial Conditions ◽  
Critical Value ◽  
Unstable Region ◽  
Stability Behavior ◽  
Peeling Process ◽  
The Stability ◽  
Complete Detachment ◽  
Limiting Value

In the present paper we propose a generalization of the model developed in Afferrante, L.; Carbone, G.; Demelio, G.; Pugno, N. Tribol. Lett. 2013, 52, 439–447 to take into account the effect of the pre-tension in the tape. A detailed analysis of the peeling process shows the existence of two possible detachment regimes: one being stable and the other being unstable, depending on the initial configuration of the tape. In the stability region, as the peeling process advances, the peeling angle reaches a limiting value, which only depends on the geometry, on the elastic modulus of the tape and on the surface energy of adhesion. Vice versa, in the unstable region, depending on the initial conditions of the system, the tape can evolve towards a state of complete detachment or fail before reaching a state of equilibrium with complete adhesion. We find that the presence of pre-tension in the tape does not modify the stability behavior of the system, but significantly affects the pull-off force which can be sustained by the tape before complete detachment. Moreover, above a critical value of the pre-tension, which depends on the surface energy of adhesion, the tape will tend to spontaneously detach from the substrate. In this case, an external force is necessary to avoid spontaneous detachment and make the tape adhering to the substrate.

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