Showing 2 results for Pashaei
Hamid Pashaei Adl, Samad Roshan Entezar,
Volume 6, Issue 1 (International Journal of Optics and Photonics (IJOP) Vol 6, No 1, Winter-Spring 2012)
Abstract
In this paper, the optical properties of one dimensional fractal structures are investigated. We consider six typical fractal photonic structures: the symmetric dual cantor-like fractal structure, the asymmetric dual cantor-like fractal structure, the single cantor-like fractal structure, the symmetric dual golden-section fractal structure, the asymmetric dual golden-section fractal structure and the single golden-section fractal structure. By using the transfer matrix method the transmission spectra of these structures are simulated. The calculation results shows that the transmission spectrum of the symmetric dual cantor-like fractal structure is self-similar and the peak numbers in the transmission spectra of the SDGSFS also follow the principals of special fractal structures. It is also shown that in the symmetric dual golden-section fractal structure the localization of modes which appears within the stop band increases and getting closer to the middle of the gap by increasing the number of string.
Ms. Fateme Salehi-Marzijani, Dr. Seyede Zahra Shoursheini, Dr. Hamidreza Shirvani-Mahdavi, Ms. Somayye Pashaei,
Volume 8, Issue 1 (International Journal of Optics and Photonics (IJOP) Vol 8, No 1, Winter-Spring 2014)
Abstract
The identification and concentration of heavy metals, which may be so harmful for the body, is determined by the method of calibration-free laser-induced breakdown spectroscopy using a special strategy. First, the plasma temperature is obtained using the Boltzmann plot. Then, a line with an inappreciable self-absorption is considered for each element as the reference. The modified intensities of other lines of the element are calculated through their self-absorbed intensities in terms of the reference intensity. The plasma temperature is again computed by line pair ratio method. This procedure is carried out by an iterative algorithm until the self-absorption coefficient of selected lines converges on one. In the last step, the corrected temperature is evaluated by the Boltzmann plot drawn using true (non self-absorbed) line intensities of each element. The concentration of the elements is finally determined by the corrected temperature and intensities. The results indicate that the accuracy of this method in determining the concentrations is significantly better than the normal way.
