scholarly journals Static, free vibration and stability analysis of three-dimensional nano-beams by atomistic refined models accounting for surface free energy effect

2013 ◽  
Vol 50 (9) ◽  
pp. 1460-1472 ◽  
Author(s):  
Gaetano Giunta ◽  
Yao Koutsawa ◽  
Salim Belouettar ◽  
Heng Hu
Keyword(s):  
Free Energy ◽  
Stability Analysis ◽  
Free Vibration ◽  
Surface Free Energy ◽  
Three Dimensional ◽  
Energy Effect

scholarly journals A three-dimensional surface elastic model for vibration analysis of functionally graded arbitrary straight-sided quadrilateral nanoplates under thermal environment

2020 ◽  
Vol 37 ◽  
pp. 72-99
Author(s):  
A Shahabodini ◽  
R Ansari ◽  
H Rouhi
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Thermal Environment ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Mapping Technique ◽  
Elastic Model ◽  
Size Dependent ◽  
Present Solution ◽  
Effect Of Surface

Abstract In this paper, a three-dimensional (3D) size-dependent formulation is developed for the free vibrations of functionally graded quadrilateral nanoplates subjected to thermal environment. The plate model is constructed within the frameworks of the Gurtin–Murdoch surface and the 3D elasticity theories. In this way, the effect of surface free energy and all the components of stress and strain tensors are considered without any initial assumption on them as there is no need to assume the variation of transverse normal stress inside the bulk material in advance. The variational differential quadrature approach and the mapping technique are applied to derive a discretized weak form of the governing equations. The present solution method bypasses the transformation and discretization of the higher order derivatives appearing in the equations of the strong form. The effects of surface stress, thermal environment, material gradient index and geometrical properties on the size-dependent vibrational behavior of quadrilateral nanoplates are investigated. It is observed that the thermal load intensifies the effect of surface free energy on the natural frequency of the nanoplates. The present model is exact in the extent of the continuum models and can be employed for structures with any thickness–span ratios.

Analysis of nano-plates by atomistic-refined models accounting for surface free energy effect

2013 ◽  
Vol 225 (1) ◽  
pp. 31-51 ◽  
Author(s):  
G. Giunta ◽  
Y. Koutsawa ◽  
S. Belouettar ◽  
H. Hu
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Effect

Surface free energy effect on bacterial retention

2006 ◽  
Vol 48 (2) ◽  
pp. 143-147 ◽  
Author(s):  
C.I. Pereni ◽  
Q. Zhao ◽  
Y. Liu ◽  
E. Abel
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Effect

The effect of surface free energy on the fracture behaviors of nanoparticle-reinforced composites

2021 ◽  
pp. 108128652110276
Author(s):  
YM Zhang ◽  
M Fan ◽  
ZM Xiao ◽  
WG Zhang
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Dominant Role ◽  
Plastic Zone Size ◽  
Analytical Investigation ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Energy Effect ◽  
Inelastic Structures ◽  
Fracture Behaviors

By considering the surface free energy effect, an analytical investigation on the fracture behaviors of nanoparticle-reinforced composites was performed in this study. The plastic zones ahead of the crack tips based on the Irwin model were introduced in our analysis, which has a significant influence on the fracture toughness of inelastic structures, especially for polymer and metal matrix composites. Take copper and aluminum nanoparticles as examples, comprehensive parametric studies were conducted to investigate the interaction between a Griffith crack and the nearby nanoparticle. It was found that for nanoparticles with the radius of less than 10 nm, apart from the mechanical property of the nanoparticle, the surface free energy effect plays a dominant role in determining the fracture behaviors of the nanoparticle-reinforced composites. Moreover, taking the surface free energy into account, a decrease in the plastic zone size is obtained, particularly for the crack tip nearer the nanoparticle.

scholarly journals Streptococcus mutans adhesion on nickel titanium (NiTi) and copper-NiTi archwires: A comparative prospective clinical study

2016 ◽  
Vol 87 (3) ◽  
pp. 448-454 ◽  
Author(s):  
Kirubaharan S. Abraham ◽  
Nithya Jagdish ◽  
Vignesh Kailasam ◽  
Sridevi Padmanabhan
Keyword(s):  
Surface Roughness ◽  
Free Energy ◽  
Streptococcus Mutans ◽  
Surface Free Energy ◽  
Three Dimensional ◽  
Dynamic Contact Angle ◽  
Surface Characteristics ◽  
Dynamic Contact ◽  
Nickel Titanium ◽  
Prospective Clinical Study

ABSTRACT Objectives: To compare the adhesion of Streptococcus mutans to nickel titanium (NiTi) and copper-NiTi (Cu-NiTi) archwires and to correlate the adhesion to surface characteristics (surface free energy and surface roughness) of these wires. Materials and Methods: A total of 16 patients undergoing orthodontic treatment with preadjusted edgewise appliances were included in the study. 0.016” and 0.016” × 0.022” NiTi and Cu-NiTi archwires in as-received condition and after 4 weeks of intraoral use were studied for S mutans adhesion using real-time polymerase chain reaction. Surface roughness and surface free energy were studied by three-dimensional surface profilometry and dynamic contact angle analysis, respectively. Results: S mutans adhesion was more in Cu-NiTi archwires. These wires exhibited rougher surface and higher surface free energy when compared to NiTi archwires. Conclusions: S mutans adhesion, surface roughness, and surface free energy were greater in Cu-NiTi than NiTi archwires. Surface roughness and surface free energy increased after 4 weeks of intraoral exposure for all of the archwires studied. A predominantly negative correlation was seen between the cycle threshold value of adherent bacteria and surface characteristics.

Smectic A-Smectic B interface : faceting and surface free energy measurement

1989 ◽  
Vol 50 (24) ◽  
pp. 3527-3534 ◽  
Author(s):  
P. Oswald ◽  
F. Melo ◽  
C. Germain
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Energy Measurement ◽  
Smectic A

Examination of the lubricant storing and releasing ability of thermally sprayed surfaces

2011 ◽  
Vol 2 (2) ◽  
pp. 101-105
Author(s):  
L. Fazekas ◽  
Z. S. Tiba ◽  
G. Kalácska
Keyword(s):  
Free Energy ◽  
Surface Energy ◽  
Surface Free Energy ◽  
Essential Role ◽  
Index Number ◽  
Adhesion Ability ◽  
Thermally Sprayed ◽  
Proper Operation

Abstract The lubricant storing and releasing ability of the thermally sprayed surfaces plays an essential role in the proper operation of the components. In the case of porous sprayed surfaces the lubricant storing and releasing ability depends mainly on porosity and the surface energy (adhesion susceptibility). The adhesion ability can also be expressed indirectly with an index number that is by determining the surface free energy.

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