List of Articles ضریب شکست

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  1 - The simulating of optical sensor based on selective resonance coupling
  sahel Javahernia
  Refractive index sensors are one of the most widely used sensors in the bioelectronics and optoelectronics industries. The use of materials and structures that can detect the refractive index of unknown materials has important applications in biochemistry and medical en More

  Refractive index sensors are one of the most widely used sensors in the bioelectronics and optoelectronics industries. The use of materials and structures that can detect the refractive index of unknown materials has important applications in biochemistry and medical engineering. In this paper, a polymer-based dual-core photon crystal fiber is introduced to measure the refractive index of a fluid. The size of the holes of the analyte cores and the light-transmitting solid core are engineered to be able to pass the main single mode. Due to its cheapness, high mechanical ability and ease of fabrication, the photon crystal fiber substrate is made of PMMA polymer. After simulating the structure and using the existing mathematical relations and examining the diffusion modes, for the complete transfer of light from the solid core to the core of the analyte channel, a fiber length of 0.13 cm has been obtained. The simulation results show that for a refractive index of 1.44, a sensitivity value of 1000  and a detection limit can be achieved by this sensor. All simulation steps in the field of FDTD are obtained in Lumerical software. Manuscript profile
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  2 - An investigation of bulk module , Pressure transition and electronic properties of Calcium Carbonate using pseudopotential method
  Hamdollah salehi Amin Shanbedi
  In this paper,bulk module, its derivative, compressibility ,Pressure transition and optical properties of calcium carbonate compound orthorhombic (aragonite) phases are studied. The calculations have been performed with pseudopotential method in density functional theor More

  In this paper,bulk module, its derivative, compressibility ,Pressure transition and optical properties of calcium carbonate compound orthorhombic (aragonite) phases are studied. The calculations have been performed with pseudopotential method in density functional theory framework by using Quantume Espresso package. The results of stability and strain transfer indicate that the results of the approximationGGA-NC are more consistent with the values of the experimental strainer than the other two approximations.The obtained refractive index for orthorombic phase (wateryte) are in the directionsx,y and z of 1.273, 1.274 and 1.433, respectively.The amount of optical gap for the orthorombic phase is also direction x,y and z.The results obtained are well consistent with other available data. Manuscript profile
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  3 - Calculation of optical properties of Na2S in different phases
  Hamdollah salehi Emel Abdoullahi
  In this paper, the optical properties of Na2S in various fcc, orthorhombic and hexagonal structural phases have been investigated. Calculations have been performed by using wien2k package which is based on density functional theory and FP-LAPW method. The LDA band struc More

  In this paper, the optical properties of Na2S in various fcc, orthorhombic and hexagonal structural phases have been investigated. Calculations have been performed by using wien2k package which is based on density functional theory and FP-LAPW method. The LDA band structure calculation indicate that Na2S is a direct band gap semiconductor in each three studied phases. The optical band gaps obtained from imaginary part of dielectric function are in good agreement with structural band gaps. According to our results the maximum peak of the imaginary part of dielectric function, occurred at the energy range which coincide to the maximum peak of obsorbation and extinctions curves on that range. Similar behavior is observed for real part of dielectric function in comparison to refraction and reflections diagrams. Manuscript profile
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  4 - Investigation of optical properties of HgTe using density functional theory
  Hamdollah salehi Zinab Izadi
  In this paper, the optical properties of HgTe compounds such as dielectric function ε (ω), Refractive coefficients, and extinction index using different approximations in three Zincblend, hexagonal and orthorhombic phases have been studied.The calculations More

  In this paper, the optical properties of HgTe compounds such as dielectric function ε (ω), Refractive coefficients, and extinction index using different approximations in three Zincblend, hexagonal and orthorhombic phases have been studied.The calculations have been performed by pseudopotential method in the framework density functional theory with GGA and LDA approximation by Quantum-Espresso package. The results obtained from the imaginary part of the dielectric function show the correspondence between the optical gap and the band gap.Also, the results of the optical parameters for the two Zincblend and hexagonal phases of the HgTe compound show that this composition has a refractive index of 3.413 in the Zincblend phase and 3.192 and 3.339 in the hexagonal phase,in direction x and z respectively. The reason for the higher refractive index in the Zincblend, than the hexagonal phase can be attributed to the quasi-metallic properties of this compound. Manuscript profile
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  5 - Evaluation of the physical and chemical properties of the essential oil obtained from the oleo-gum- resin of two populations of Ferula gummosa from Fars and Isfahan provinces
  Arife Vaez Shahrestani Razieh Azimi Atergeleh Vahid Abdousi Mehdi Mirza marzieh ghanbari jahromi
  Ferula gummosa (Barijeh) belongs to the Apiaceae family and is one of the most important pasture, medicinal and industrial plants, whose oleo-gum-resin (galbanum) has a commercial aspect. The essential oil and oleoresin of F. gummosa are widely used in the food, pharmac More

  Ferula gummosa (Barijeh) belongs to the Apiaceae family and is one of the most important pasture, medicinal and industrial plants, whose oleo-gum-resin (galbanum) has a commercial aspect. The essential oil and oleoresin of F. gummosa are widely used in the food, pharmaceutical and cosmetic industries. The aim of the present study is to investigate and compare the physicochemical properties of the essential oil obtained from the oleo-gum-resin of two F. gummosa populations from Isfahan and Fars habitats. For this purpose, the oleo-gum-resin of F. gummosa was collected from two areas in Kashan and Fars. The essential oil was then extracted from the fresh oleo-gum-resin by water and steam distillation. The essential oil was analyzed quantitatively and qualitatively using GC and GC/MS devices. The appearance, physical and chemical characteristics of the essential oil of two populations of F. gummosa, including relative density, refractive index, optical rotation, and phytochemicals of the essential oil were investigated and compared. Based on the results, the essential oil of F. gummosa is a transparent and colorless liquid with a turpentine odour and a distinct green note. The essential oil of two populations of Kashan and Fars has relative density of 0.874 and 0.869, refractive index of 1.4810 and 1.4795, and optical rotation of 11.35° and 23.52°, respectively. The results of comparing the average physicochemical characteristics of the essential oil obtained from the oleo-gum-resin of the two F. gummosa populations from Fars and Kashan indicate that there is no significant difference in the traits of relative density and refractive index, and on the other hand, there is a significant difference in the amount of optical rotation of the two essential oil samples. Based on the essential oil analysis, hydrocarbon monoterpenes including β-pinene (71% and 68.8%), δ-3-carne (9.4% and 5.2%), myrcene (3.9% and 2.4%), α-pinene (3.6% and 3.4%) and limonene (2.4% and 15.6%) were identified as the main compounds of essential oil in two F. gummosa populations from Kashan and Fars, respectively. Manuscript profile