Senthilnathan V.,Kumaraguru College of Technology |
Ganesan S.,Government College of Technology, Coimbatore
Journal of Renewable and Sustainable Energy | Year: 2010
In the area of photovoltaic, the silicon solar cell is the most popular and it has issues such as stability and scaling up cost. On the other hand, a dye-sensitized solar cell (DSSC) is one of the most promising candidates for a high-performance solar cell in the next generation, since it is fabricated by a simple manufacture process at relatively low cost. The focus of interest in this research paper is to mention the usage of maiden single and simple apparatus of spray pyrolysis thin film deposition to fabricate the electrode and counterelectrode for DSSC. It involves the novelties introduced in the instrumentation of the apparatus and the characterizations (x-ray diffraction, scanning electron microscope, and atomic force microscopy) of the prepared thin films for the fabricated DSSC. In this work, the pomegranate fruit dye is used to sensitize the nano- TiO2. © 2010 American Institute of Physics.
Vijayakumari A.,Amrita University |
Devarajan A.T.,Amrita University |
Devarajan N.,Government College of Technology, Coimbatore
International Journal of Electrical Power and Energy Systems | Year: 2012
This paper presents a model based hardware simulator to emulate a photovoltaic (PV) array/module for all operating conditions. For making the model accurate the values of manufacturer dependent parameters pertaining to a PV array are extracted from the published data sheet of the array by a curve fitting based extraction technique. The proposed simulator consists of a microcontroller controlled switched mode DC-DC converter. The mathematical model of the PV array is embedded in the controller with provisions for the user to enter the required ambient conditions. A feedback compensator is implemented to achieve fast response and good stability and to minimize the steady-state error. As a test case to design, develop and test for compliance the published data of 115 W solar panel Shell S115 has been used. The prototype is tested for steady-state and transient conditions. The experimental results of the simulator are presented. The results are compared with the cell characteristics available in literature and compliance is confirmed. © 2012 Elsevier Ltd. All rights reserved.
Suriyanarayanan N.,Government College of Technology, Coimbatore
Physica B: Condensed Matter | Year: 2010
Copper indium disulphide (CuInS2), is a good absorber material for photovoltaic applications. In this work, CuInS2 is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS2 thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS2 films. The XRD patterns confirm the well defined single phase composition of CuInS2 films grown from 300 to 350 °C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS2 thin films with chalcopyrite structure. D2d point symmetry group is associated with the CuInS2 crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS2 films is found to be in the order of 105-106 cm-1 in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS2 polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates. © 2010 Elsevier B.V. All rights reserved.
Vijayakumari V.,Sri Krishna College of Engineering And Technology |
Suriyanarayanan N.,Government College of Technology, Coimbatore
European Journal of Scientific Research | Year: 2012
Diabetic retinopathy (DR) is a common retinal complication associated with diabetes. Along with optic disk and blood vessel of normal patients, the diabetic patient's retinal image has exudates. Sometimes exudates and optic disk are similar in brightness, color and contrast. It is very important to differentiate them. The blood vessel is extracted and the meeting point of the blood vessel is the center of the optic disk. In this paper, few methods for the extraction of blood vessel are discussed and by using this other anatomical features in the retinal image can be extracted. © 2012 EuroJournals Publishing, Inc.
Krishna B.V.,Saranathan College of Engineering |
Baskaran K.,Government College of Technology, Coimbatore
IET Signal Processing | Year: 2013
Fast signal processing implementation techniques for detection and classification of power quality (PQ) disturbances are the need of the hour. Hence in this work, a parallel computing approach has been proposed to speed up the feature extraction of PQ signals to facilitate rapid building of classifier models. Considering that the Fourier, the one-dimensional discrete wavelet, the time-time and the Stockwell transforms have been used extensively to extract pertinent time-frequency features from nonstationary and multi-frequency PQ signals, acceleration approaches using data and task parallelism have been employed for parallel implementation of the above time-frequency transforms. In the first approach, data parallelism was applied to the Stockwell transform and the time-time transform-based feature extraction methods separately to alleviate capability problems. Also, data parallelism was applied to Fourier and wavelet-based feature extraction methods independently to alleviate capacity problems. Secondly, a combination of task and data parallelism was applied to speed up S-transform based three-phase sag feature extraction. Experiments were conducted using shared-memory and distributed memory architectures to try out the effectiveness of the proposed parallel approaches. The performances of these parallel implementations were analysed in terms of computational speed and efficiency in comparison with the sequential approach. © The Institution of Engineering and Technology 2013.