Cochin University of Science and Technology is a government-owned autonomous science and technology university in Kochi , Kerala, India. Founded in 1971, it has three campuses: two in Kochi and one in Kuttanad, Alappuzha, 66 km inland. The university awards degrees in engineering and science subjects at the undergraduate, postgraduate and doctoral levels. Nearly 2,000 students engage yearly in undergraduate and postgraduate study at CUSAT. Wikipedia.
Abish B.,Cochin University of Science and Technology |
Mohanakumar K.,Cochin University of Science and Technology
Global and Planetary Change | Year: 2013
In this study, the influence of the El Nino Southern Oscillation (ENSO) on the transport, deposition and distribution of absorbing aerosols over the Indian subcontinent during a period of 30. years (1982 to 2011) is investigated. The analysis reveals that the changes in the zonal circulation over the tropics have a significant effect on the aerosol loading over the Indian region. This interannual variability in aerosol concentration arises due to its increasing dependence on the development of sea surface temperature (SST) anomalies over the tropical Pacific Ocean. Significant statistical correlations in SST anomalies confirm this relationship. During El Nino conditions, warm SST anomalies cause the zonal circulation to become pronounced with well-defined areas of rising and sinking motion along a mean air flow driven by convection at the west (the Arabian Peninsula), and subsidence to the east (Indian subcontinent). These intense westerlies at 700. hPa altitude transport large quantities of aerosols from the Arabian Peninsula towards the east and deposit them over the Indian subcontinent. However, a weaker and less organised zonal circulation system associated with cold SST anomalies suppresses the aerosol loading during the La Nina phase. •During El Nino the zonal circulation over the Indian subcontinent gains strength.•Mean air flow at 700hPa gets intensified from Arabian Peninsula towards India.•Strong upper level subsidence converges these aerosols over the Indian region.•Warm SST anomalies at Nino 3.4 region influence this zonal circulation.•Zonal circulation gets suppressed during La Nina decreasing aerosol concentration. © 2013 Elsevier B.V.
Jayalatha G.,Cochin University of Science and Technology |
Kutty S.K.N.,Cochin University of Science and Technology
Materials and Design | Year: 2013
Composites based on polystyrene and natural rubber at a ratio of 85/15 were prepared by melt mixing with nylon-6 fibres using an internal mixer. The loading of short nylon-6 fibre, untreated and resorcinol formaldehyde latex (RFL)-treated, was varied from 0 to 3wt.%. Tensile and flexural test samples were punched out from sheets and tested to study the variation of mechanical and dynamic mechanical properties. The tensile behaviour of the composite has been determined at three different strain rates (4.1×10-4s-1, 2×10-3s-1 and 2×10-2s-1). Both the tensile strength and Young's modulus of the composite increased with strain rate. The tensile strength, tensile modulus, flexural strength and flexural modulus increased with the increase in fibre content up to 1wt.%, above which there was a significant deterioration in the properties. The RFL-treated fibre composites showed improved mechanical properties compared to the untreated one. Dynamic mechanical analysis (DMA) showed that the storage modulus of the composite with RFL-treated fibre was better compared to the untreated one. The fibre-matrix morphology of the tensile fractured specimens was studied by scanning electron microscopy (SEM). The results suggested that the RFL treatment of nylon fibre promoted adhesion to the natural rubber phase of the blend, thereby improving the mechanical properties of the composite. © 2012.
Vinodkumar M.N.,Cochin University of Science and Technology |
Bhasi M.,Cochin University of Science and Technology
Accident Analysis and Prevention | Year: 2010
Safety management practices not only improve working conditions but also positively influence employees' attitudes and behaviours with regard to safety, thereby reducing accidents in workplace. This study measured employees' perceptions on six safety management practices and self-reported safety knowledge, safety motivation, safety compliance and safety participation by conducting a survey using questionnaire among 1566 employees belonging to eight major accident hazard process industrial units in Kerala, a state in southern part of India. The reliability and unidimesionality of all the scales were found acceptable. Path analysis using AMOS-4 software showed that some of the safety management practices have direct and indirect relations with the safety performance components, namely, safety compliance and safety participation. Safety knowledge and safety motivation were found to be the key mediators in explaining these relationships. Safety training was identified as the most important safety management practice that predicts safety knowledge, safety motivation, safety compliance and safety participation. These findings provide valuable guidance for researchers and practitioners for identifying the mechanisms by which they can improve safety of workplace. © 2010 Elsevier Ltd. All rights reserved.
Kannan V.,Government College Kattappana |
Sreekumar K.,Cochin University of Science and Technology
Journal of Molecular Catalysis A: Chemical | Year: 2013
A series of clay supported metal containing catalysts were prepared and their catalytic performance was evaluated in the synthesis of tetrasubstitued imidazoles under solvent free condition. It was found that K10 supported titanium catalyst showed higher activity compared to other catalysts. The catalysts were characterized by FTIR, XRD, TG/DTA, BET surface area and SEM. The general applicability of the method was demonstrated for the synthesis of tetra- substituted imidazoles from aldehydes and amines containing various electron donating and electron withdrawing substituents. The diversity of the catalyst was studied by synthesis of benzimidazoles and quinoxalines. The mechanism of formation of the products is explained in detail. The catalyst was found to be active for three cycles. © 2013 Elsevier B.V. All rights reserved.
Subash N.,Indian Council of Agricultural Research |
Ram Mohan H.S.,Cochin University of Science and Technology
Agricultural and Forest Meteorology | Year: 2012
Indo-Gangetic Plains (IGP), accountable for the region's food security, has undergone climatic fluctuations and variability during the last three decades under the influence of natural or fast trend of population growth, urbanization and industrial development. The objective of this study is to understand the trends of climatic variables over 5 selected locations during the last 25-30 years and the variability of recorded and simulated rice-wheat system yield using DSSAT-CSMv4.5. There was no significant change in rainfall over the years in both the rice and the wheat growing seasons at all the sites except Hisar. The annual change in the rainfall trend was -28.9mm/year (P<0.05) and during the rice season it was -20.5mm/year (P<0.01) for Hisar. Incidentally, higher coefficient of variation of 79% has been noticed in annual rainfall. The district average yields of rice varied from 0.9t/ha at Samastipur to 3.8t/ha at Ludhiana. Rice yields decreased from the west to east IGP. The time trend of rice yield ranged from -0.023t/ha per year at Samastipur to 0.055t/ha per year in Faizabad. Negative trends were observed in Samastipur and was statistically significant (P<0.05). In wheat, the yield trend ranged from 0.01t/ha per year at Samastipur to 0.096t/ha per year in Hisar. All the sites had a positive yield trend and at three stations (Hisar, Faizabad and Kanpur) have significant positive trends (P<0.05). Wheat yields appeared to be increasing throughout the IGP. The comparison of observed and simulated rice and wheat yield shows that there is very good agreement between them based on Spearman correlation coefficient (r s), significant at P<0.05 level for all the sites except Samastipur. Thus DSSAT-CSMv4.5 can be used for determining the impact of climatic variability on rice-wheat productivity. © 2012 Elsevier B.V.
Sudheer K.S.,Christ College |
Sabir M.,Cochin University of Science and Technology
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011
In this Letter we consider modified function projective synchronization of unidirectionally coupled multiple time-delayed Rossler chaotic systems using adaptive controls. Recently, delay differential equations have attracted much attention in the field of nonlinear dynamics. The high complexity of the multiple time-delayed systems can provide a new architecture for enhancing message security in chaos based encryption systems. Adaptive control can be used for synchronization when the parameters of the system are unknown. Based on Lyapunov stability theory, the adaptive control law and the parameter update law are derived to make the state of two chaotic systems are function projective synchronized. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers. © 2011 Elsevier B.V.
Sudheer K.S.,Cochin University of Science and Technology
Chaos (Woodbury, N.Y.) | Year: 2010
Recently introduced function projective synchronization in which chaotic systems synchronize up to a scaling function has important applications in secure communications. We design coupling function for unidirectional coupling in identical and mismatched oscillators to realize function projective synchronization through open-plus-closed-loop coupling method. Numerical simulations on Lorenz system, Rossler system, hyperchaotic Lorenz, and hyperchaotic Chen system are presented to verify the effectiveness of the proposed scheme.
Reshmi R.,Cochin University of Science and Technology |
Sugunan S.,Cochin University of Science and Technology
Journal of Molecular Catalysis B: Enzymatic | Year: 2013
Large mesoporous cellular foam (LMCF) materials were synthesized using the microemulsion templating route. For the enzyme stabilization, β-glucosidase was immobilized onto mesocellular silica foams (MCFs) in a simple and effective way, a process achieved using enzyme adsorption followed by glutaraldehyde (GA) crosslinking. This resulted in the formation of crosslinked enzyme aggregates (CLEAs) of nanometer scale. The structural and chemical properties of these prepared materials were characterized by TG, CPMAS NMR and nitrogen adsorption measurements. The crosslinked immobilizates retained activity over wider ranges of temperature and pH than those of the free enzyme. Kinetic parameter (K m) of the immobilized β-glucosidase is lower than that of its free counterpart. The resulting CLEA was proved to be active and recyclable up to 10 cycles without much loss in activity. This demonstrates its prospects for commercial applications. The immobilizate exhibited enhanced storage stability characteristics than the native enzyme. In contrast to adsorbed GL and covalently bound glucosidase, the resulting crosslinked enzyme aggregates (CLEAs) showed an impressive stability with high enzyme loadings. © 2012 Published by Elsevier B.V.
Kumar T.P.,Cochin University of Science and Technology
Journal of biomedical science | Year: 2010
Curcumin, an active principle component in rhizome of Curcuma longa, has proved its merit for diabetes through its anti-oxidative and anti-inflammatory properties. This study aims at evaluating the effect of curcumin in modulating the altered dopaminergic receptors, CREB and phospholipase C in the cerebral cortex and cerebellum of STZ induced diabetic rats. Radioreceptor binding assays and gene expression was done in the cerebral cortex and cerebellum of male Wistar rats using specific ligands and probes. Total dopaminergic receptor binding parameter, B(max) showed an increase in cerebral cortex and decrease in the cerebellum of diabetic rats. Gene expression studies using real time PCR showed an increased expression of dopamine D1 and D2 receptor in the cerebral cortex of diabetic rats. In cerebellum dopamine D1 receptor was down regulated and D2 receptor showed an up regulation. Transcription factor CREB and phospholipase C showed a significant down regulation in cerebral cortex and cerebellum of diabetic rats. We report that curcumin supplementation reduces diabetes induced alteration of dopamine D1, D2 receptors, transcription factor CREB and phospholipase C to near control. Our results indicate that curcumin has a potential to regulate diabetes induced malfunctions of dopaminergic signalling, CREB and Phospholipase C expression in cerebral cortex and cerebellum and thereby improving the cognitive and emotional functions associated with these regions. Furthermore, in line with these studies an interaction between curcumin and dopaminergic receptors, CREB and phospholipase C is suggested, which attenuates the cortical and cerebellar dysfunction in diabetes. These results suggest that curcumin holds promise as an agent to prevent or treat CNS complications in diabetes.
Sreekumar A.,Cochin University of Science and Technology
Energy Conversion and Management | Year: 2010
The solar air heater was 46 m2 and recorded a maximum temperature of 76.6 °C. The dryer was loaded with 200 kg of fresh pineapple slices 5 mm thick. The initial moisture content of 82% was reduced to the desired level (<10%) within 8 h. The performance of the dryer was analyzed in detail by three methods namely annualized cost, present worth of annual savings, and present worth of cumulative savings. The cost of drying 1 kg pineapple worked out to Rs. 11 which was roughly half of that of an electric dryer. The payback period worked out to 0.54 year, much less than the estimated life of the system (20 years). © 2010 Elsevier Ltd. All rights reserved.