Faculty Publications
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Item Estimation of potential tidal energy along the West Coast of India(World Scientific, 2018) Mendi, V.; Seelam, J.K.; Rao, S.Tidal energy is one of the clean and non-depleting renewable energy sources. In contrast to other clean sources, such as wind, solar, geothermal etc., tidal energy can be predicted for years ahead. Also, the medium, seawater, is more than 800 times denser than air and the astronomic nature of the underlying driving mechanism results in an essentially predictable resource, although subject to weather-related fluctuations. These features make it an important energy source for global power production in the near future. There are various types of tidal power plants across the world with varying tidal elevation. Also the method of conversion of the tidal energy into electrical energy is site specific. For example, we can adopt conventional method to extract energy in high tidal regions. But when it comes to low tidal regions like the southern India where tidal elevation measurements does not exceed 2.5m, there is a need of low flow turbines which can extract higher energy from lower head. An important factor that is responsible for the velocity of tidal stream is the tidal inlet dimensions. In this paper, an attempt has been made to identify the feasible locations for extraction of potential tidal energy along the Indian Coast. © 2018 World Scientific Publishing Co. Pte. Ltd.Item Induced stresses in blasting gallery panel during depillaring based on field instrumentation(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2012) Kumar Reddy, S.; Sastry, V.R.Selection of a suitable mining method for economical and safe underground extraction of a thick coal seam is an extremely delicate process and brings a number of geo-technical parameters into consideration. In fact, single lift working of full thickness of a thick coal seam has always a verge over the multi slice working due to favorable economics and high production and productivity. Charbonnage de France (CdF) proposed Blasting Gallery (BG) for extraction of virgin thick seams as well as developed pillars in thick seams in single lift. The method was very successful resulting in 85% of extraction with high productivity. But, this method experienced strata control problems during final extraction. Due to strata problems, the method was not successful at East Katras Colliery where overriding of the pillars occurred in one panel. Two BG panels (BG 2/2 and BG 1/10 panels) at GDK No. 8 Incline, Singareni Collieries Company Ltd. (SCCL) were also closed prematurely due to strata problems. In this paper, strata monitoring data of stress cells in pillars of a blasting gallery panel is analyzed for the induced stresses in a Blasting Gallery panel during depillaring in specific geo-mining and working conditions of a underground mine in Southern part of India. © 2012 CAFET-INNOVA TECHNICAL SOCIETY.Item Gallery monitoring in blasting gallery panel during depillaring - A case study(2013) Kumar Reddy, S.; Sastry, V.R.About 50% of coal reserves in India are in seams thicker than 4.5m, which come under the category of thick seams, the exploitation of which is consistently posing challenges to the mining engineers. Extraction of thick seams by conventional hand section method is neither productive nor effective from the conservation point of view. The percentage of extraction by hand section mining in thick seams is as low as 25-30%. Sand stowing for working of thick seams cannot be considered as an option because the cost is prohibitive. Sand has become an increasingly scarce commodity along with timber. Blasting gallery (BG) method of depillaring thick coal seam is one of the productive methods with high production, productivity, economic and conservation. In this method, stability of workings and easily cavability of goaf is very important for safely extraction of pillars, safety of men and machinery. In this paper, strata monitoring data of load cells in galleries of a blasting gallery panel, where spoiling in pillars, instability of galleries and displacement of supports are monitored and analyzed during depillaring in specific geo-mining and working conditions of a underground mine in southern part of India.Item Real-time implementation of an amplitude-locked loop: A validation on the dSPACE DS1006-based platform(2013) Gonda, J.M.; Sumam David, S.The extraction of harmonics and/or the fundamental from a distorted waveform is an important process in the implementation of custom-power devices. Several schemes towards this have been proposed in the past. Among these, the algorithms based on synchronous (with respect to the supply voltages) extraction (both in phase and amplitude) have certain established advantages over the others. Amplitude-locked loops (ALLs) have been in use in signal-communication systems but are limited to sinusoidal inputs. There is a need for fast and rugged algorithms to synchronously extract harmonics and/or the fundamental from a distorted waveform in many power system applications. In this paper a real-time implementation of a novel scheme, which is based on an adaptation of an ALL, is presented for synchronous extraction of harmonics and/or the fundamental from a distorted periodic waveform. The operation of the algorithm, its performance, and its design aspects are briey discussed. The main features of this ALL are simplicity, speed of operation, noise rejection, availability of both fundamental and harmonics without much additional processing, and excellent insensitivity to distortion (robustness). Furthermore, it is applicable to single-phase or 3-phase systems. This paper reports a real-time hardware implementation of the algorithm, thereby validating it. The algorithm is implemented on a real-time hardware-emulation platform, a dSPACE modular system (configured around the DS1006 processor board). It is tested for various cases of interest and the results are presented. © Tübi?tak;.Item An optimization study of microwave assisted extraction of oil from oily sludge using response surface methodology(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2014) Kumar, B.; Raj Mohan, B.Petroleum oily sludge, a hazardous waste, generated by the refineries and at the production sites in huge quantities comprises of a mixture of petroleum hydrocarbons, asphaltenes, long chain paraffinic wax, waste water, sediments and metals. The present study is aimed to recover oil from the petroleum oily sludge using n-heptane as the solvent in microwave assisted solvent extraction process and to optimize the process variables for the recovery of oil from the oily sludge. The simultaneous effects of process variables such as irradiation time (2 - 10 minutes), solvent to sludge ratio (40 – 80 wt %), reactant volume (100 – 300 ml) and microwave power (80 – 400 W) on the recovery of oil were evaluated. A central composite design (CCD) and response surface methodology (RSM) were used for the optimization of the extraction process. Based on the CCD, quadratic model was developed to correlate the extraction process variables with the responses and the model was analysed using appropriate statistical method (ANOVA). Optimization of process variables shows that the maximum recovery of oil was about 88.6% at 100 ml of reactant volume with microwave power output of 351 W at 6.5 minutes of irradiation time with 58.99% of nheptane to sludge ratio. © 2014 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item An integrated Control Approach and Power Management of Stand-alone Hybrid Wind/PV/Battery Power Generation System with Maximum Power Extraction Capability(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2015) Sabhahit, N.S.; Gaonkar, D.N.The production of electricity from renewable energy sources like wind and photovoltaic energy has increased in recent years, due to environmental problems and the shortage of traditional energy sources. In this article we present a detailed mathematical model and a control scheme for hybrid wind and PV based DG system with battery and maximum power extraction capability for isolated mode of operation. The wind power generation system uses wind turbine (WT), a permanent magnet synchronous generator (PMSG), a three-phase diode rectifier bridge, DC/DC boost converter with maximum power point tracking (MPPT) controller. The PV generation system uses PV array, a boost converter with maximum power point tracking controller. Both sources and battery are connected to common dc bus with a dc link capacitor and supply power to load through PWM voltage source inverter. The overall control system consists of MPPT controller for both Wind and PV power system, a bi-directional DC-DC converter controller for battery energy storage management and load side inverter controller for voltage and frequency regulation. Control strategies for individual system components of the proposed system are designed with a view to achieve an acceptable level of voltage and frequency regulation while extracting the maximum power from wind and PV system. The performance of the developed hybrid system is investigated in terms of voltage and frequency regulation capability under changing wind, solar irradiation and variable load conditions.Item Synthesis of silver nanoparticles using medicinal Zizyphus xylopyrus bark extract(Springer Nature, 2015) Babu, B.; Devadiga, A.; Shetty K, V.K.; Saidutta, M.B.In the present paper, biosynthesis of silver nanoparticles using Zizyphus xylopyrus bark extract is reported. Z. xylopyrus bark extract is efficiently used for the biosynthesis of silver nanoparticles. UV–Visible spectroscopy showed surface plasmon resonance peaks in the range 413–420 nm confirming the formation of silver nanoparticles. Different factors affecting the synthesis of silver nanoparticles like methodology for the preparation of extract, concentration of silver nitrate solution used for biosynthesis and initial pH of the reaction mixture were studied. The extract prepared with 10 mM AgNO3 solution by reflux extraction method at optimum initial pH of 11, resulted in higher conversion of silver ions to silver nanoparticles as compared with those prepared by open heating or ultrasonication. SEM analysis showed that the biosynthesized nanoparticles are spherical in nature and ranged from 60 to 70 nm in size. EDX suggested that the silver nanoparticles must be capped by the organic components present in the plant extract. This simple process for the biosynthesis of silver nanoparticles using aqueous extract of Z. xylopyrus is a green technology without the usage of hazardous and toxic solvents and chemicals and hence is environment friendly. The process has several advantages with reference to cost, compatibility for its application in medical and drug delivery, as well as for large-scale commercial production. © 2014, The Author(s).Item An efficient framework for segmentation and identification of tumours in brain MR images(Inderscience Enterprises Ltd., 2016) Parameshwari, D.S.; Aparna., P.In this research work, two efficient textural feature extraction (TFE) algorithms (TFEA-I and TFEA-II) are proposed for a class of brain magnetic resonance imaging (MRI) applications. TFEA-I employs higher order statistical cumulant, namely, Kurtosis in order to generate a feature set based on the probability density function (PDF) of generalised Gaussian model that represents thewavelet coefficient energies of the sub-bands of decomposed image. TFEA-II derives a feature set employing cooccurrence matrix model for second order statistical characterisation of wavelet coefficients. In conjunction with TFEA-I and TFEA-II, we propose segmentation framework to compute coarse and smooth segmented boundaries for the tumour. When compared with the conventional TFEA methods reported in the literature, the use of proposed TFEA-I and TFEA-II results in two important advantages; considerable reduction in the feature set size and elimination of the need for using specialised feature selection/reduction algorithms thereby making them highly attractive for a class of brain MR imaging application. © © 2016 Inderscience Enterprises Ltd.Item Feature pattern based representation of multimedia documents for efficient knowledge discovery(Springer New York LLC barbara.b.bertram@gsk.com, 2016) Pushpalatha, K.; Ananthanarayana, V.S.The rapid growth of multimedia documents has raised huge demand for sophisticated multimedia knowledge discovery systems. The knowledge extraction of the documents mainly relies on the data representation model and the document representation model. As the multimedia document comprised of multimodal multimedia objects, the data representation depends on modality of the objects. The multimodal objects require distinct processing and feature extraction methods resulting in different features with different dimensionalities. Managing multiple types of features is challenging for knowledge extraction tasks. The unified representation of multimedia document benefits the knowledge extraction process, as they are represented by same type of features. The appropriate document representation will benefit the overall decision making process by reducing the search time and memory requirements. In this paper, we propose a domain converting method known as Multimedia to Signal converter (MSC) to represent the multimodal multimedia document in an unified representation by converting multimodal objects as signal objects. A tree based approach known as Multimedia Feature Pattern (MFP) tree is proposed for the compact representation of multimedia documents in terms of features of multimedia objects. The effectiveness of the proposed framework is evaluated by performing the experiments on four multimodal datasets. Experimental results show that the unified representation of multimedia documents helped in improving the classification accuracy for the documents. The MFP tree based representation of multimedia documents not only reduces the search time and memory requirements, also outperforms the competitive approaches for search and retrieval of multimedia documents. © 2016, Springer Science+Business Media New York.Item Optimised microwave-assisted biosynthesis of silver nanoparticles from Nothapodytes foetida leaf extracts and its anti-microbial activities(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2016) Roopesh, R.; Geedhika, G.; D'Souza, J.; Anandhan, S.; Bhat, K.U.; Jaya M, J.; Fathima B, S.; Mohan Balakrishnan, R.M.The present investigation reports the biogenesis of silver nanoparticles (Ag NPs) using extracts of a medicinal plant Nothapodytes foetida. Total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) assay were carried out for the microwave-assisted extract (MAE) of N. foetida using methanol as solvent and the conditions for extraction were optimised by response surface methodology (RSM). The effects of operating variables such as extraction time, temperature and ratio of sample to solvent were studied using central composite design (CCD). A mathematical model with a high determination coefficient (R2) for TPC (0.991) and FRAP (0.995) was obtained. The optimal conditions of extraction for TPC were 48.6 ºC, 23.15 min and 2.04:30 (g/mL) and for FRAP 52.31ºC, 12.32 min and 1.67: 30 (g/mL). Under these conditions, the experimental yields of TPC and FRAP were 2.426 mg gallic acid equivalents (GAE)/g dry powder and 14.985mg of FeSO4·7H2O/g of dry powder, respectively. Ag NPs were characterised using UV–Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The synthesised Ag NPs have also shown potent activity against the human pathogenic Staphylococcus aureus. © 2016 Informa UK Limited, trading as Taylor & Francis Group.