Volume 1 Issue 2
Authors: Sarhan. Y. Atwa
Abstract: The present paper is concerned with the investigation of disturbances in a homogeneous thermoelastic diffusion. The formulation is applied to the generali thermoelasticity, isotropic temperature-dependent elastic medium with fractional order eneralized based on the fractional time derivatives under the effect of diffusion. The analytical expressions for displacement components, stresses, temperature field, concentration and chemical potential are obtained in the physical domain by using the normal mode analysis technique. These expressions are calculated numerically for a copper-like material and shown graphically. Effect of fractional parameter and presence of diffusion are analyzed theoretically and numerically. Comparisons are made with the results predicted by the fractional and without fractional order in the presence and absence of diffusion.
Keywords: Generalized Thermoelasticity; Fractional Parameter; Diffusion; Relaxation Time; Normal Mode Analysis
Authors: U S Rai; Manjeet Singh
Abstract: The solidification mechanism of a monotectic alloy is quite complicated due to wide freezing range of temperature and large density difference of the two liquid phases involved. However, the diffusion model by Jackson and Hunt and the wetting model by Cahn, have been successfully applied to various metallic and organic systems to explain the solidification behavior of different monotectics. Using these models, in the present paper, a current status of solidification of binary monotectics of metal as well as that of organic origins has been described and various methods to overcome the problems associated with this have been highlighted. Due to low transformation temperature, ease of purification, transparency, minimized convection effects and wider choice of materials, organic systems are better than those of metallic systems for detailed investigation of the parameters which control the mechanism of solidification, which in turn, controls the properties of materials. Organic monotectic systems, suitable for experiments under reduced gravity condition, are potentially useful to explore new manufacturing techniques to get novel materials to cater the needs of modern civilization.
Keywords: Monotectic Crystallization; Binary Monotectics; Binary Organic Solidification; Mechanism of Solidification
Authors: Ming Wang; Hui Hao; Liben Li; Zhi Zhang; Haitao Yan; Xiaoyan Zhao; Zhiqiang Zhen
Abstract: We use the changes of colloidal photonic crystals photonic band-gap center wavelength to study the refractive index sensing by experiment. The changes in the center wavelength of the colloidal crystals photonic band-gap are analyzed in theory, the mould is designed to obtain a controllable self-assembly method, colloidal crystals are observed by scan microscope and the band-gap is measured by infrared spectrometer. The results show that the measured results are well agree with the theoretical analysis. The experimental device is designed to test liquid refractive index. The couple of the fibers are used to measure the band-gap of colloidal crystals and the results are also analyzed in theory. The results show that the band-gap of colloidal crystals can be used to measure the liquid refractive index. The new sensing mechanism is formed and it provides a new application of colloidal crystals in the sensing.
Keywords: Colloidal Photonics Crystals; Refractive Index; Sensing; Photonic Band-Gap