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We have investigated systematically the energetics of arsenic terminated GaAs(001) surfaces. Available surface models proposed in the literature have been considered, and relaxation and surface energies of each model have been calculated using an empirical many-body potential energy function comprising two and three-body atomic interactions.

Using a simplified model, the surface energy of the Si/SiO2 interface in silicon nanowires (SiNWs) is derived. Our theoretical results show that the nanowires along <112> and <110> have very low surface energy, so their yields should be high. Experimental observation testifies that the SiNWs fabricated by the oxide-assisted growth (OAG) are mostly of these two orientations. This supports the consideration that during growth process, surface energy is the chief factor to determine the axis orientation of nanowires under OAG.

This paper has reported the effect of oxygen and argon plasma treatments of CIIR rubber using Attenuated Total Reflectance (ATR) and surface energy measurements. Plasma treatment led to changes in the surface energy from 31 to 45.7 mN/m. Plasma treatment conditions influenced both the changes in surface energy and stability, and they also became more difficult to obtain good contact angle measurements. However, plasma treatments made the interfacial properties to be stabilized. ATR measurements revealed that changes in surface energy with treatment time are due mostly to increased oxygen functionality.

At present, research is actively being conducted into composite materials using natural fibers and thermoplastic resins that can serve as eco-friendly materials. However, the weak interfacial bonding shape between natural fibers and thermoplastic resins leads to low mechanical properties in the natural fiber-reinforced polymer composite. This study examined the usage of basalt fibers (BFs) and polypropylene (PP) to address this issue. Plasma surface modification (PSM) was performed on the surface of the BF to improve the interfacial bonding force between the fiber and the thermoplastic resin. Studies on monomer selection (HMDSO), plasma generation conditions (3 kV), and surface modification time (20–150 s) were conducted to determine the optimal conditions for PSM. FT-IR analysis was performed to confirm the surface modification and the fracture surface was observed after the mechanical properties were measured. The experimental results confirmed the effect of PSM on the BF resulting in about 10% improvement on the related mechanical properties.

In this paper we construct and analyze a two-well Hamiltonian on a 2D atomic lattice. The two wells of the Hamiltonian are prescribed by two rank-one connected martensitic twins, respectively. By constraining the deformed configurations to special 1D atomic chains with position-dependent elongation vectors for the vertical direction, we show that the structure of ground states under appropriate boundary conditions is close to the macroscopically expected twinned configurations with additional boundary layers localized near the twinning interfaces. In addition, we proceed to a continuum limit, show asymptotic piecewise rigidity of minimizing sequences and rigorously derive the corresponding limiting form of the surface energy.

We analyze an elastic surface energy which was recently introduced by G. Napoli and L. Vergori to model thin films of nematic liquid crystals. We show how a novel approach in modeling the surface’s extrinsic geometry leads to considerable differences with respect to the classical intrinsic energy. Our results concern three connected aspects: (i) using methods of the calculus of variations, we establish a relation between the existence of minimizers and the topology of the surface; (ii) we prove, by a Ginzburg–Landau approximation, the well-posedness of the gradient flow of the energy; (iii) in the case of a parametrized torus we obtain a stronger characterization of global and local minimizers, which we supplement with numerical experiments.

ZnSe epilayers have been grown under various Se/Zn atomic flux ratios in the range of 0.22–2.45 at a substrate temperature of 350°C on Zn pre-exposed GaAs (111) A surfaces. Real time reflection high energy electron diffraction (RHEED) observations have shown a transition from a two-dimensional (2D) to a three-dimensional (3D) growth mode. The transition time depends directly upon the growth rate. A detailed discussion is presented to explore the cause of this change in the growth mode.

We used the molecular dynamics simulation based on the Stillinger–Weber (SW) interatomic potential to calculate the high-index surface energies of surfaces containing any of the stereographic surfaces of silicon at zero temperature. An empirical formula based on the structural unit model was generalized for high-index surfaces. Our simulated results show that the generalized formula can give a good estimation of the surface energy and structural feature of the high-index surfaces not only on the edge of stereographic but also within it. Our simulation and empirical formula results reveal that the closest surface has the lowest energy, so the closest (101) surface has the lowest surface energy and the (101), (111) and (001) surfaces are the extremum on the curve of surface energy versus orientation angle. Both the theoretical simulation results and the empirical formula calculation results are consistent with the available first-principles theoretical data.

Laser surface melting is known to alter surface energy and wettability of a few engineering materials, but its effect on magnesium alloys has never been reported. Effort was made to study how Nd:YAG laser irradiation influenced surface energy of an AZ91D magnesium alloy. Contact angle measurement was carried out using three types of liquids to make it possible to calculate the surface energy quantitatively based upon the acid–base theory. The laser irradiation was found to enhance surface wettability significantly and lead to a drastic increase in surface energy from 25.82 to 40.78 mJ/m². The change in surface property was attributed to the laser-induced refinement of α-Mg and β-Mg₁₇Al₁₂ phases and enrichment of Al in the microstructure.

Surface energies of strained Cu surfaces were studied systematically using first-principles methods. Results showed that the strain-stabilization of Cu surface was anisotropic and strongly related to the strain distribution. This strain-induced approach could be used as an effective way to engineer the surface energies of metals.

In this paper, we present first principles calculations of the energetic, electronic and magnetic properties of the variant termination of TiAl (001) and Ni/TiAl (001) surfaces with and without hydrogen atoms. The calculations have been performed within the density functional theory using full-potential linearized augmented plane wave method. The generalized gradient approximation (GGA) is utilized as the exchange-correlation energy. The octahedral site is the stable absorption site of H atom in the β-TiAl system. This absorption reduces the cohesive energy of β-TiAl system due to increase in the lattice constant. The surface energy for both TiAl (001) terminations is calculated. The stable adsorption site of H atoms on the variant termination of TiAl (001) surface is performed. The adsorption energy of hydrogen on Ti is more energetic than that on Al. The adsorption of H atom on both terminations of H/Ni/TiAl (001) is more preferable at the bridge site. The adsorption energies are enhanced on Ni atom due to the contraction between d-Ni bands and TiAl substrate band.

This study examines the critical surface energy of manganese sulfite (MnSO${}_3)$ crystalline thin film, produced via chemical bath deposition (CBD) on substrates. In addition, parachor, which is an important parameter of chemical physics, and its relationship with grain size, film thickness, etc., has been investigated for thin films. For this purpose, MnSO₃ thin films were deposited at room temperature using different deposition times. Structural properties of the films, such as film thickness and average grain size, were examined using X-ray diffraction; film thickness and surface properties were measured by and atomic force microscope; and critical surface tension of MnSO₃ thin films was measured with Optical Tensiometer and calculated using Zisman method. The results showed that critical surface tension and parachor of the films have varied with average grain size and film thickness. Critical surface tension was calculated as 32.97, 24.55, 21.03 and 12.76mN/m for 14.66, 30.84, 37.07 and 44.56nm grain sizes, respectively. Film thickness and average grain size have been increased with the deposition time and they were found to be negatively correlated with surface tension and parachor. The relationship between film thickness and parachor was found as $\mathrm{\text{P}}=-0.1856\mathrm{\text{t}}+183.45;$ whereas the relationship between average grain size and parachor was found as $\mathrm{\text{P}}=-0.8911\mathrm{\text{D}}+150.52.$ We also showed the relationships between parachor and some thin films parameters.

Nanoscale beams might not be considered uniform isotropic since the energy of the surface layer and microstructure of the bulk material highly affect the mechanical characteristics of the beams. Herein, the simultaneous effects of energy of the surface and microstructure of the bulk on the dynamic response and stability of beam-type electromechanical nanocantilevers are investigated. A bilayer model has been developed which incorporates the strain energy of the surface atoms as well as the microstructure-dependent strain energy of the bulk. The Gurtin–Murdoch surface elasticity in conjunction with the modified couple stress theory (MCST) is applied to derive the governing equation. Since the classical assumption for zero normal surface stresses is not consistent with the surface equilibrium assumption in Gurtin–Murdoch elasticity, the presence of normal surface stresses is incorporated. The von Karman nonlinear strain is employed to derive the governing equation. The presence of gas rarefaction at various Knudsen numbers is considered as well as the edge effect on the distribution of Coulomb and dispersion forces. The mode shapes of the nanobeam are determined as a function of the surface and microstructure parameter and the nonlinear governing equation is solved using Galerkin method. The dynamic response, phase plane and stability threshold of the nanocantilever are discussed.

We study the effect of boundary rugosity in nematic liquid crystalline systems. We consider a highly general formulation of the problem, able to simultaneously deal with several liquid crystal theories. We use techniques of Gamma convergence and demonstrate that the effect of fine-scale surface oscillations may be replaced by an effective homogenized surface energy on a simpler domain. The homogenization limit is then quantitatively studied in a simplified setting, obtaining convergence rates.

A measurement system based on crack-opening method has been developed to measure the fracture toughness of silicon direct bonding wafers. The theory of crack-opening method was introduced and amended according to the shape of the specimen. The parameters and function required in the measurement of bond energy were mentioned, and the selection principle of thickness of the razor was given. A new experimental device based on IR vision and image processing in the measurement was developed. Finally, a contrast experiment was carried out successfully and the error of the method was analyzed which validated the feasibility and the localization of the method.

Apart from long-known and applied nanostructures like carbon black for tyres or pigments for coatings nanotechnology has created highly sophisticated structures used for nano/molecular electronics, diagnostics, drug delivery, UV-absorbers etc. Often the main question to be solved analytically is the local determination of tiny amounts of chemicals resulting in an ever increasing need for highly sensitive as well as locally resolved techniques. Applications of techniques like mass spectroscopy, transmission electron microscopy as well as ultracentrifugation to problems arising from nanotechnology in the chemical industry will be described.

Adequate proliferating model including each cell's growth and division in 3D is key for the simulation of tissue growth in early stages as embryo, avascular tumor and so on. This paper proposed a novel model to perform the simulation based on a nonlinear finite element method. With the mechanism of cellular growth controlled by total energy of volume and surface of cells, the surface of each cell is divided by triangular elements and the nodal displacements determine the variation of the cellular surface and volume uniquely when cells grow. The nonlinear finite element equations of nodal displacements were deduced by the minimum energy increment in each growth's step. Further, by using the volume-based algorithm to determine cellular division and the modified penalty function method, the nonlinear procedure of the cellular proliferation (growth-division-regrowth) was solved. The numerical results show that the method can simulate both tissue and tissue's every cell well in each growth-division step, and will do great help to model the growth of varied tissues in their early stages.

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.

In this paper, the compression of an isolated cell by two rigid indenters is analyzed. The neo-Hookean model is employed to characterize the hyperelastic behavior of biological cells. Owing to the greatly increased ratio between surface energy density and elastic modulus, surface energy plays important roles in the mechanical performance of biological cells. Using the dimensional analysis method and a finite element approach incorporating surface energy, we study the elastic compression of hyperelastic cells at finite deformation and give the explicit relations of contact radius and indent depth depending on compressive load. Our results reveal that surface energy obviously influences both the local deformation and the overall responses of hyperelastic cells at finite deformation. The obtained results are useful to determine the elastic properties of biological cells from indent-depth curves accurately.

In this work, a study on curved electrostatically-actuated nanobeams incorporating surface energy is presented. The beam is modeled according to Euler–Bernoulli beam theory and the Gurtin–Murdoch theory of surface stress is used to incorporate surface energy effects in beam modeling. To verify the accuracy of the model, its predictions were compared to numerical results reported in previous literature on the static behavior of fixed-fixed and fixed-free nanobeams subjected to DC electrostatic potential. The results of this study demonstrate that the stiffness of both fixed–fixed and fixed-free nanobeams is influenced by surface stress. Furthermore, the findings highlight the significant impact of the electrostatic fringing field on the response of the nanobeams.