M. Salimi and H. Khademizadeh,
Volume 17, Issue 1 (7-1998)
Abstract
In this paper, collapse behavior of simple and reinforced thin-walled channel- section beams, subjected to three- point bending, is investigated. Many simple channel- section beams of different geometry and some reinforced ones were tested, and their strengths after collapse were obtained thoroughly. Since the available theories in this area are complicated and little attention has been paid to the case of reinforced thin-walled beams, simple models were used and further developed to give an account of the collapse load and the deformation energy of such beams. The method proposed in this paper is valuable both to the further studies of the symmetric thin-walled beams with arbitrary cross-section and to its practical application of such beams as energy absorbers.
A. Jafari, S. Khademi, M. Farahmandjou, A. Darudi, R. Rasuli,
Volume 38, Issue 2 (Journal of Advanced Materials-Summer 2019)
Abstract
Titanium dioxide nanoparticles (TiO2) are known as a widely used photocatalyst. In order to improve the performance of these nanoparticles, the recombination of the electron-cavity pair must be reduced and the absorption rate of the visible region should be expanded. One way to increase the performance of these nanoparticles is using cerium doped TiO2. In the present study, pure and doped titanium dioxide nanoparticles were made by the electrical discharge method. The effect of cerium dopants on the structural, morphological and optical properties were studied by x-ray diffraction (XRD), scanning electron microscopy (FESEM), diffused reflection spectroscopy (DRS), photoluminescence (PL) and infrared fourier transform (FTIR) spectroscopy analyses. XRD analysis revealed that the size of TiO2 nanocrystals was decreased to 7.7 nm. The FESEM morphology of the samples also showed that the uniformity of the Ce doped TiO2 was decreased. Further, the DRS results indicated that the band gap energy of Ce-TiO2 was decreased to 2.24 eV. The photoluminescence results demonstrated that the intensity of PL was reduced for the Ce-TiO2 sample, which reduced the recombination of the electron-hole coupling and increased the photocatalytic activity in the doped sample.
