ABSTRACT
For sensing various samples of polluted water and various sodium chloride concentrations using an angular surface plasmon resonance (ASPR), we have introduced a conventional structure and a hybrid heterostructure in the current research. The suggested structures are composed of silver metal, dielectric layers, silver nanocomposite, and a sensing medium. The reflectance spectra of all structures in the visible region were obtained through the utilization of the transfer matrix method by using the angular interrogation method depending on the Kretschmann configuration. Through our findings, five substrate parameters have been optimized to attain the utmost level of sensitivity across all structures: the thickness of Ag-metal, the type and thickness of dielectric materials, the host material type and the volume fraction of nanoparticles for the nanocomposite layer. In this regard, the suggested sensor provides excellent performance with a sensitivity of 448.1°[Formula: see text], signal-to-noise ratio of 0.787, sensor resolution of 0.284°, and figure of merit of 78.766 RIU-1. Therefore, we believe that the introduced design of our ASPR sensor presents a good candidate for an accurate and efficient detection of low concentrations of contaminated water and sodium chloride as well.
ABSTRACT
We have presented in the current work a novel idea for simulating the irradiation behaviors of the nuclear fuel pellets in nuclear reactors by using a one-dimensional defective phononic crystal (1D-DPnC) design was presented. The transmission spectra of the incident mechanical waves were considered basic data for expressing the characteristics of different nuclear fuel-pellets. Herein, the density, sound speed, and Young's modulus of the fuel-pellets represent the key parameters that are influenced by the irradiation behaviors of these pallets. Mixed plutonium-uranium oxide (MOX) nuclear fuel is considered the main fuel in the present study. In addition, a comparison is performed for this fuel with other types of nuclear fuels. Moreover, the mechanical properties of these MOX-pellets are dependent on the porosity, the ratio of oxygen-to-metal (O/M), and the plutonium (Pu-content). The theoretical treatments depend on the transfers matrix method to compute the transmission spectra through the 1D-DPnC. The numerical findings provided that the MOX-pellet has the highest performance compared to other fuel pellets and with sensitivity equal to 59.388 × 103 Hz s/m. It was also reported that the effects of the percentage of the O/M and Pu- content in MOX had a minor effect in a comparison with the impact of porosity. The theoretical simulation agreed extremely with the experimental data reported for these nuclear fuels. Because of the close relationship between sound speed and density, this sensor can be utilized to monitor the porosity, O/M, Pu-content, and density of fuel-pellets as a quick and non-destructive evaluation technique in a nuclear fuel fabrication laboratory. This article has proven theoretically that MOX fuel produced from nuclear waste of uranium dioxide and plutonium dioxide gives excellent results compared to other types of nuclear fuels, and this agrees with experimental researches. Thus, it may contribute in preserving the environment from nuclear waste, and this can be considered a novel kind of purification of environmental pollution treatment.
ABSTRACT
In this research, a theoretical investigation of the one-dimensional defective photonic crystals is considered for the detection of gamma-ray radiation. Each unit cell of the considered one-dimensional photonic crystals (1D PhCs) is composed of two layers designed from porous silicon infiltrated by poly-vinyl alcohol polymer doped with crystal violet (CV) and carbol fuchsine (CF) dyes (doped-polymer) with different porosity. In addition, a single layer of doped-polymer is included in the middle of the designed 1D PhCs to stimulate the localization of a distinct resonant wavelength through the photonic band gap. In particular, the appearance of this resonant mode represents the backbone of our study towards the detection of γ-ray radiation with doses from 0 to 70 Gy. The Bruggeman's effective medium equation, the fitted experimental data to the refractive index of the doped-polymer, and the Transfers Matrix Method (TMM) serve as the mainstay of our theoretical treatment. The numerical findings provide significant contributions to some of the governing parameters such as the thicknesses of the considered materials on the performance of the presented sensor, the effect of incidence angle and the porosity of the considered materials on the resonance wavelength. In this regard, at optimum values of these parameters the sensitivity, quality factor, signal-to-noise ratio, detection limit, sensor resolution, and figure of merit that are obtained are 205.7906 nm RIU-1, 9380.483, 49.315, 2.05 × 10-5 RIU, 3.27 × 10-5, and 2429.31 RIU-1, respectively. Therefore, we believe that the suggested design could be of significant interest in many industrial, medical, and scientific applications.
ABSTRACT
New (to the best of our knowledge) photonic crystal optical filters with unique optical characteristics are theoretically introduced in this research. Here, our design is composed of a defect layer inside one-dimensional photonic crystals. The main idea of our study is dependent on the tunability of the permittivity of graphene by means of the electro-optical effect. The transfer matrix method and the electro-optical effect represent the cornerstone of our methodology to investigate the numerical results of this design. The numerical results are investigated for four different configurations of the defective one-dimensional photonic crystals for the electric polarization mode. The graphene as a defect layer is deposited on two different electro-optical materials (lithium niobate and polystyrene) to obtain the four different configurations. The electro-optical properties of graphene represent the main role of our numerical results. In the infrared wavelength range from 0.7 µm to 1.6 µm, the reflectance properties of the composite structures are numerically simulated by varying several parameters such as defect layer thickness, applied electrical field, and incident angle. The numerical results show that graphene could enhance the reflectance characteristics of the defect mode in comparison with the two electro-optical materials without graphene. In the presence of graphene with lithium niobate, the intensity of the defect mode increased by 5% beside the shift in its position with 41 nm. For the case of polystyrene, the intensity of the defect mode increased from 6.5% to 68.8%, and its position is shifted with 72 nm. Such a design could be of significant interest in the sensing and measuring of electric fields, as well as for filtering purposes.
