In this paper, surface and piezoelectric effects on the vibration behavior of NANOWIRES (NWs) are investigated by using a Timoshenko beam model. The electric field equations and the governing equations of motion for the piezoelectric NWs are derived with the consideration of surface effects. By the exact solution of the governing equations, an expression for the natural frequencies of NWs with simply-supported boundary conditions is obtained. The effects of piezoelectricity and surface effects on the vibrational behavior of Timoshenko NWs are graphically illustrated. A comparison is also made between the predictions of Timoshenko beam model and those of its Euler-Bernoulli counterpart.Additionally, the present results are validated through comparison with the available data in the literature.

We briefly reviewed the existing research on the ecotoxicity of NANOWIRES and suggested directions for further study. NANOWIRES are technological innovations that can benefit humans. However, it is important to consider the effects of NANOWIRES on the environment. Only a few studies have reported acute and chronic ecological toxicity of NANOWIRES on aquatic and terrestrial organisms, and limited research papers have reported antibacterial effects of NANOWIRES. It is assumed that NANOWIRES have a toxic mechanism similar to that of nanoparticles or ions, but the mechanism remains unknown because so little research has been conducted on the ecological toxicity of NANOWIRES. More in-depth assessments of the chronic toxicity, bioavailability, cytotoxicity, and genotoxicity of NANOWIRES on various species are needed.

The transport properties of oligo(ethyne) dithiolates coupled with gold electrodes is calculated using the non-equilibrium Green’s functions technique. The effect of molecular wire length on current-voltage characteristics for (-C≡C-)n n = 1-5 is investigated. The calculated decay coefficient at low bias voltage is (0.025 ± 0.002 Ǻ-1) which is found to be lower than that of alkanthiols. Results reveal that the HOMO-LUMO gap of the oligo(ethyne)s are correlated to the reciprocal of the number of triple bonds.

Perovskite calcium titanate (CaTiO3) NANOWIRES with average diameters in the range of 120-130 nm were grown by hydrothermal treatment of commercial anatase-titania (TiO2) and calcium chloride in aqueous sodium hydroxide solution (2.5-13 M). Reactions were carried out in temperature range of 110-150°C at various pH (9-13) for 12-72 h. The study revealed that these parameters affect the crystal morphology and size of crystallites. Reaction products obtained at different stages were characterized by thermogravimetry (TG) and differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The XRD analysis revealed the formation of CaTiO3 phases with orthorhombic crystal structure. Thermal analysis results showed that anatase-TiO2 was thermally stable below 400°C and at higher temperatures anatase transforms to rutile phase whereas CaTiO3 was stable up to 850°C.