A facile strategy for the fabrication of polycaprolactone (PCL) nanofibers containing gold nanoparticles (AuNPs) is proposed. The method is based on electrospinning nanosuspensions loaded with passivated Au nanoparticles. The optical property of gold nanoparticles synthesized was observed by UV-visible absorption spectra. Morphology and structure of the Au-PCL hybrid nanofibers were characterized by scanning electron microscopy, scanning transmission electron microscopy, and Fourier transformed infrared spectroscopy. The results of investigations by UV-visible and dynamic light scattering confirmed the presence of gold nanoparticles with diameters less than 10 nm. The STEM images show the presence of gold nanoparticles and gold agglomerates with diameter around 30 to 180 nm distributed over the surface of nanofibers, which is likely due to the increased incidence of agglomerations of AuNPs, due to drying process used.

Thermal and optical properties of two different nanofluids containing SiO 2 and TiO 2 semiconductor nanoparticles were studied by thermal lens spectrometry (TLS) and spectrophotometry. In the case of SiO 2 nanofluids the transmission electron microscopy technique was used to obtain the SiO 2 nanoparticle sizes to investigate the size effect of these nanoparticles on the sample thermal diffusivity which is important in some medical applications such as photothermal-modulated drug delivery systems. On the other hand for the case of TiO 2 nanofluids, the photopyroelectric technique, TLS, scanning electron microscopy, and X-ray diffraction were employed to investigate the concentration effect on the thermal properties of these nanofluids. Thermal diffusivities and effusivities as functions of the TiO 2 nanoparticle concentrations were obtained. From the experimental results, an incremental increase in the thermal diffusivities and effusivities was observed when the nanoparticle concentration was increased, indicating that the nanoparticle concentration is an important factor to be considered to obtain nanofluids with more thermal efficiency which are required for some applications, such as degradation of residual water.

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Gold nanoparticles were chemically conjugated with lipoic acid to control their optical properties. Z-scan and other optical techniques were used to characterize the non-linear behavior of the resulting nanostructured materials. The results show that the nonlinearity is of thermal origin, which can be controlled by the use of lipoic acid as well as other organic molecules conjugated onto metal nanoparticles. In particular, the presence of lipoic acid increases n 2 , θ and dn/dt.

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In the present work, nanofluids containing spherical TiO2 nanoparticles were mixed in water, to have various concentrations with the average particle diameter of 81.3 nm. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction techniques were used to characterize the TiO2 nanoparticles. Photothermal techniques, thermal lens spectrometry (TLS) and photopyroelectric (PPE) were used to measure the thermal diffusivity and thermal effusivity of the nanofluids respectively. The experimental results show that the thermal diffusivity (D) increased with the increase in TiO2 nanoparticle concentration. It was also possible to see that thermal effusivity (e) had a similar behavior as the thermal diffusivity, where both the values increased with the concentration rate and finally a comparison with literature values show good agreement with the thermal parameters of water.

A rubber engine mount (EM) is a mechanical coupling between the engine and the chassis, and its main function is to diminish, in the chassis, the amplitude of vibrations caused for the engine operation. Such vibrations cause discomfort for vehicle passengers and reduce the EM lifetime. To increase the comfort of vehicle passengers and the lifetime of the EM, this paper presents an EM optimization by means of reducing three main criteria: the EM mass, the displacements transmitted to the chassis, and the mechanical stress in the EM rubber core. For carrying out the EM optimization, the optimum global determination by linking and interchanging kindred evaluators (GODLIKE), assisted by artificial neural networks (ANN) and finite element method (FEM), was used. Because of the optimization process, a reduction greater than 10 % was achieved in the three criteria in comparison with a baseline design. The frequency responses were compared and showed that although the optimization was carried out for the range of 5 Hz to 30 Hz the trend of reduced responses continues beyond this range. These results increased the comfort of vehicle passengers and the lifetime of the EM; in addition, the reduction of mass diminishes its production costs.