Showing 6 results for Oct
Marziyeh Ghanavati Nejad, Syd Mohamad Bagher Ghrrashi, Mostafa Zahedifar,
year 23, Issue 0 (2-2017)
Abstract
In the present study, irregular needle-like TiO2 nanotubes developed through anodization on Ti layer substrate deposited on the FTO by sputtering method and also TiO2 nanoparticles coated by Dr.blade method which was deposited on the FTO were compared in the form off dye-sensetive solar cells (DSSCS). Ti deposition process was carried out by sputtering method for 6 hours for deposition of 2.200 µ thickness on FTO. Next Tio2 nanotube developed through anodiztion in 120 V voltage to produce irregular needle-like nanotube pattern. Then anodized samples were annealed in 450℃ temperature. Also Tio2 nanoparticle deposited on FTO by Dr.Blade method, weree annealed in final 550℃ temperature after several heating. In this research XRD, AFM and SEM analysis were used to evaluate thee samples.
Parto Eijadi Maghsoodi, Esmaeil Heydari,
year 26, Issue 0 (2-2020)
Abstract
Oxygen is one of the most crucial elements on Earth; therefore, the ability to measure it precisely is of great importance. Various methods of oxygen measurement has been developed up until now. In this paper, the aim is to present an optical in-situ oxygen sensor for dissolved oxygen sensing in water using a metalloporphyrin complex. Thus, a thin film is produced consisting of platinum octaethyl porphyrin as the oxygen sensitive probe doped in a polystyrene matrix using spin coating method. Considering the absorption spectrum of the dye, a 532nm Nd:YAG laser is used as the excitation light. The oxygen sensor is characterized by measuring the phosphorescence intensity for different oxygen concentrations.
Zahra Baghbani Tehrani, Esmaeil Heydari, Mohammad Hossein Majles Ara,
year 26, Issue 0 (2-2020)
Abstract
In this paper, we investigate the photoluminescence of platinum octaethylporphyrin doped in polydimethylsiloxane in the presence of oxygen. Polydimethylsiloxane is a suitable matrix for platinum porphyrin in aqueous media. An increase in dissolved-oxygen concentration in water leads to depletion of photoluminescence intensity. Quenching is the result of non-radiative energy transfer from excited phosphorescent molecules to the oxygen molecules via direct collision. Thus optical spectroscopy is employed to investigate the impact of dissolved oxygen concentration on the photoluminescence intensity.
Hamed Ghodsi, Elahe Rastegar Pashaki, Ahmad Amjadi, Peyman Rajai,
year 26, Issue 0 (2-2020)
Abstract
Optical coherence tomography in the Fourier domain due to its non-invasive nature and high resolution has become a routine tool in ophthalmology for detection and control of many diseases in the last two decades. In this paper, a novel method based on the image contrast the scans at the interfaces has been proposed and theoretically explained for decoupling refractive index and thickness of the layers. Also, error analysis has been done on this method which results in mean error lower than 2% on the generated reference data. The proposed method also has been checked for sensitivity to the background and foreground refractive indexes. In case of 10% error in background and foreground refractive indexes, mean error in calculation of the refractive index and thickness of the layers are less than 2.5%. Additionally, numerical procedure of this method has been explained and applied to several scan images of the retina and the resulted image has been illustrated.
S Fatemeh Yari Gharahnaz, Esmaeil Heydari,
year 27, Issue 2 (2-2021)
Abstract
Oxygen is essential for living creatures however it could be detrimental to food. Here, we investigate the application of phosphorescence material to study the oxygen presence in food packages. Therefore, a disk-shape film of platinum complex as phosphorescence materials in polystyrene matrix is prepared. 410nm laser beam is used for excitation due to its absorption spectrum. There is considerable change in the phosphorescence intensity in the test box filled with and without oxygen.
Shadi Torabi, Jafar Bakhtiar Shohani, Hamidreza Mohamadi, Rahele Kafieh,
year 28, Issue 2 (3-2022)
Abstract
- In this paper, density of capillaries of a real human eye in OCT images using image processing is calculated. First, capillaries are detected using morphological image processing. The shadows of the main vessels which are exists in superficial images are removed using image processing. In the next step, the precise location of macula which is located in retina is determined using morphological functions. Then, a circle with 2mm radius is considered and segmented to four areas. In the final step, density of white pixels which are capillaries around macula is calculated precisely
