Journal of Molecular and Engineering Materials

The problem of incident plane waves at the interface of micropolar thermoelastic half-space with voids and micropolar elastic half-space with voids has been attempted. The amplitude and energy ratios of various reflected and refracted waves for the incident $P$- and $S$-waves are obtained with the help of appropriate boundary conditions at the interface. The effect of linear thermal expansion and microinertia on the amplitude and energy ratios due to the incident $P$- and $S$-waves are discussed. Numerically and analytically, these amplitude and energy ratios are computed to show the effect of linear thermal expansion and microinertia. It is observed that the effect of linear thermal expansion is less for incident $S$-wave and the effect of microinertia is less for incident $P$-wave.

The thermoelastic problem of clamped axisymmetric infinite hollow cylinders under thermal shock with variable thermal conductivity is presented. The outer surface of infinite hollow cylinder is considered to be thermally insulated while inner surface is subjected to an initial heating source. In addition, the cylinder is considered to be clamped at its inner and outer radii. Generalized thermoelasticity theories are used to deal with the field quantities. All generalized thermoelasticity theories such as Green and Lindsay, Lord and Shulman, and coupled thermoelasticity (CTE) are considered as special cases of the present theory. Effects of variable thermal conductivity and time parameters on radial displacement, temperature, and stresses of the hollow cylinders are investigated.

Raman scattering (RS) was used as a powerful, efficient, and sensitive technique for studying intermolecular interactions between an organic ligand adsorbate and a metallic substrate. Functionalization of titanium (TiO₂$/$Ti) surfaces was performed using lysine (Lys) as adsorbate and later developing a hydroxyapatite (HA) layer onto this functionalized surface. The functionalization process was performed at different pH values of the interacting chemical species. Chemisorption onto the TiO₂Ti substrates through the Lys carboxylic group was demonstrated spectroscopically. Analysis of vibrational spectra showed that the CH side chain of Lys was relatively distant from the (TiO₂$/$Ti) surface, preventing direct contact with the surface. Additionally, the signals corresponding to the unbound $\gamma$-NH₂ group indicate that it is available for additional complexation. In vitro bioactivity of the Lys–TiO₂$/$Ti surface was achieved by developing an HA layer onto already functionalized TiO₂$/$Ti surfaces at various pH values. Spectroscopic data using the spectral markers of HA and Lys provided a decisive role in establishing the necessary baseline data for evidencing the intermolecular bonding. The functionalized TiO₂$/$Ti surface reactivity is linked to the specific intermolecular interactions of –COO⁻ (pH 7.0) with Ca${}^{2+}$ ions, as well as the –COOH (pH 2.0 and 12.0) groups of Lys, with the –OH groups of PO${}_4^{3-}$ belonging to HA.