| URI: | http://dyuthi.cusat.ac.in/purl/5154 |
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| Dyuthi-T2188.pdf | (1.699Mb) |
| Abstract: | We establish numerically the validity of Huberman-Rudnick scaling relation for Lyapunov exponents during the period doubling route to chaos in one dimensional maps. We extend our studies to the context of a combination map. where the scaling index is found to be different. |
| URI: | http://dyuthi.cusat.ac.in/purl/2560 |
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| Dyuthi-P0119.pdf | (905.4Kb) |
| URI: | http://dyuthi.cusat.ac.in/purl/835 |
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| Rani Joseph an ... anning electron..,1987.PDF | (6.459Mb) |
| Abstract: | Tear and wear properties of short kevlar fiber, thermoplastic polcurethane (TPU) composite with respect to fiber loading-and fiber onentation has been studied and the fracture surfaces were examined under scanning electron microscope (SEM). Tear strength first decreased up to 20 phr fiber loading and then gradually increased with increasing fiber loading. Anisotropy in tear strength was evident beyond a fiber loading of 20 phr. Tear fracture surface of unfilled TPU showed sinusoidal folding characteristics of high strength matrix. At low fiber loading the tear failure was mainly due to fibermatrix failure whereas at higher fiber loading the failure occurred by fiber breakage. Abrasion loss shows a continuous rise with increasing fiber loading, the loss in the transverse orientation of fibers being higher than that in the longitudinal orientation. The abraded surface showed lone cracks and ridges parallel to the direction of abrasion indicating an abrasive wear mechanism. In the presence of fber the abrasion loss was mainly due to fiber low. |
| URI: | http://dyuthi.cusat.ac.in/purl/882 |
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| Golok , B, S K ... opy studies............PDF | (3.154Mb) |
| Abstract: | The scattering behaviour of fractal based metallodielectric structures loaded over metallic targets of different shapes such as flat plate, cylinder and dihedral corner reflector are investigated for both TE and TM polarizations of the incident wave. Out of the various fractal structures studied,square Sierpinski carpet structure is found to give backscattering reduction for an appreciable range of frequencies. The frequency of minimum backscattering depends on the geometry of the structure as well as on the thickness of the substrate. This structure when loaded over a dihedral corner reflector is showing an enhancement in RCS for corner angles other than 90◦. |
| URI: | http://dyuthi.cusat.ac.in/purl/2725 |
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| Dyuthi-P00362.pdf | (1.120Mb) |
| Abstract: | A comprehensive overview of reclamation of cured rubber with special emphasis on latex reclamation is depicted in this paper. The latex industry has expanded over the years to meet the world demands for gloves, condoms, latex thread, etc. Due to the strict specifications for the products and the unstable nature of the latex as high as 15% of the final latex products are rejected. As waste latex rubber (WLR) represents a source of high-quality rubber hydrocarbon, it is a potential candidate for generating reclaimed rubber of superior quality. The role of the different components in the reclamation recipe is explained and the reaction mechanism and chemistry during reclamation are discussed in detail. Different types of reclaiming processes are described with special reference to processes, which selectively cleave the cross links in the vulcanized rubber. The state-of-the-art techniques of reclamation with special attention on latex treatment are reviewed. An overview of the latest development concerning the fundamental studies in the field of rubber recycling by means of low-molecular weight compounds is described. A mathematical model description of main-chain and crosslink scission during devulcanization of a rubber vulcanizate is also given. |
| URI: | http://dyuthi.cusat.ac.in/purl/821 |
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| V V Rajan and o ... d techology...,Aug2006.PDF | (17.94Mb) |
| Abstract: | Nanosized ZnO was prepared by polyol synthesis. Fluorescence spectrum of the ZnO colloid at varying pump intensities was studied. The powder was extracted and characterized by XRD and BET. The extracted powder was screen printed on glass substrates using ethyl cellulose as binder and turpinol as solvent. Coherent back scattering studies were performed on the screen printed sample which showed evidence of weak localization. The screen printed pattern showed strong UV emission. |
| URI: | http://dyuthi.cusat.ac.in/purl/2511 |
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| Dyuthi-P0134.pdf | (265.6Kb) |
| Abstract: | In the present investigation, an attempt is made to document various episodes of transgression and regression during the late Quaternary period from the study of coastal and shelf sequences extending from the inland across the beach to the shelf domain. Shore parallel beach ridges with alternating swales and occurrence of strand line deposits on the shelf make the northern Kerala coast an ideal natural laboratory for documenting the morpho-dynamic response of the coast to the changing sea level. The objectives of the study are lithographic reconstruction of environments of deposition from the coastal plain and shelf sequences; documentation of episodes of transgression and regression by studying different coastal plain sequences and shelf deposits and evolve a comprehensive picture of late Quaternary coastal evolution and sea level changes along the northern Kerala coast by collating morphological, lithological and geochronological evidences from the coastal plain and shelf sequences. The present study is confined to two shore-normal east-west trending transects, Viz. Punjavi and Onakkunnu, in the northern Kerala coast. |
| URI: | http://dyuthi.cusat.ac.in/purl/130 |
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| Dyuthi-T0144.pdf | (9.307Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5515 |
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| Dyuthi T-2557.pdf | (29.81Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/637 |
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| Bednyakov, V A, ... las at LHC, E1-2006-97.PDF | (4.982Mb) |
| Abstract: | Experimental Neutrino Physics is an active area of research in high energy physics. The investigation of the properties of this elusive particles has started since it’s discovery itself. In the standard model of particle physics, neutrinos are massless, the discovery of neutrino oscillation is the first evidence that demands the extensions of standard model. It is well established the existence of three active neutrinos, e, μ and , but recent experiments like LSND and MiniBooNE has found some anomalies in their data. These experimental data could not be explained using three flavour neutrino oscillation physics, but they could explain the anomaly by adding a fourth type neutrino called sterile neutrinos. The evidences obtained from these experiments are not yet conclusive. Search for sterile neutrino is an extensive research area in the field of neutrino physics. The main work presented in this thesis is a sterile neutrino search at MINOS (Main Injector Neutrino Oscillation Search) experiment at Fermilab, USA. MINOS is a two detector experiment at Fermilab, which studies the neutrinos produced at Fermilab Main Injector particle accelerator. MINOS Near Detector is situated at 1 km away from the source and the Far Detector is at Soudan Mine at Minnesota, 735 km away from the neutrino source. The experiment is built to study neutrino oscillation phenomena in the atmospheric sector and has made world class measurements on neutrino oscillation parameters. The MINOS experiment is also capable of looking for small perturbation in the energy spectra caused by any fourth type of neutrino and can extract the oscillation parameters. |
| URI: | http://dyuthi.cusat.ac.in/purl/5135 |
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| Dyuthi-T2169.pdf | (7.459Mb) |
| Abstract: | This thesis entitled seasonal and interannual variability of sea level and associated surface meteorological parameters at cochin.The interesting aspect of studying sea level variability on different time scales can be attributed to the diversity of its applications.Study of tides could perhaps be the oldest branch of physical oceanography.The thesis is presented in seven chapters. The first chapter gives, apart from a general introduction, a survey of literature on sea level variability on different time scales - tidal, seasonal and interannual (geological scales excluded), with particular emphasis on the work carried out in the Indian waters. The second chapter is devoted to the study of observed tides at Cochin on seasonal and interannual time scales using hourly water level data for the period 1988-1993. The third chapter describes the long-term climatology of some important surface oceanographic and meteorological parameters (at Cochin) which are supposed to affect the sea level. The fourth chapter addresses the problem of seasonal forecasting of the meteorological and oceanographic parameters at Cochin using autoregressive, sinusoidal and exponentially weighted moving average techniques and testing their accuracy with the observed data for the period 1991-1993. The fifth chapter describes the seasonal cycles of sea level and the driving forces at 16 stations along the Indian subcontinent. It also addresses the observed interannual variability of sea level at 15 stations using available multi-annual data sets. The sixth chapter deals with the problem of coastal trapped waves between Cochin and Beypore off the Kerala coast using sea level and atmospheric pressure data sets for the year 1977. The seventh and the last chapter contains the summary and conclusions and future outlook based on this study. |
| Description: | Center for earth science studies |
| URI: | http://dyuthi.cusat.ac.in/purl/3125 |
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| Dyuthi-T1099.pdf | (9.503Mb) |
| Abstract: | The present study which is the first of its kind in this region is an attempt to generate adequate information on the relative abundances, the seasonal and spatial variations as well as on the source and fate of organic compounds found associated with the dissolved, particulate and sedimentary compartments of Chalakudy river system. The study aimed at investigating variations, the relative proportion of dissolved, particulate and sedimentary fractions of these materials as well as the pollution extent so as to be able to comment on the present condition of this river-estuarine system. This thesis focuses attention on the role of biogeoorganics in modifying the ecological and environmental condition of the dissolved, particuIate and sediment compartments with their minute variability subjected to various physical, chemical and biogeochemical processes. A scheme of study encompassing all these objectives provides the frame work for the present investigation. |
| Description: | Department of Chemical Oceanography,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2663 |
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| Dyuthi-T0717.pdf | (7.066Mb) |
| Abstract: | The thesis describes the importance of Indian EEZ, definition and the various factors affecting primary production, general account of phytoplankton and its importance in marine ecosystem etc. In review of literature, general oceanography of Arabian Sea and Bay of Bengal and hydrography of eastern Arabian Sea and western Bay of Bengal. It deals with the distribution patterns of primary production, chlorophyll a, phytoplankton composition and particulate organic carbon in the eastern Arabian Sea and western Bay of Bengal during different seasons. Factors that affect primary productivity are irradiance, temperature, stability of the surface waters, nutrients and zooplankton grazing. The differential biological response of eastern Arabian Sea and western Bay of Bengal to monsoonal regimes. A precise estimation on the primary production of the entire EEZ of India on a regional basis and on a seasonal scale would be the only way to achieve any kind of predictive assessment on the fish stock and their sustainable yield. This study mainly envisages the qualitative and quantitative aspects on the magnitude of phytoplankton standing crop and production of organic carbon and their relationship to environmental characteristics during summer monsoon, Inter monsoon and winter monsoon periods in the east and west coasts of the Indian EEZ.This study revealed that the seasonality exerts a great impact on the biological production in the eastern Arabian Sea and western Bay of Bengal. High biological production may be the reason why most of the fish landings are Concentrated in the west coast of India than east coast. The present data on Phytoplankton production rate and the species composition will provide a meaningful ground for evaluations of exploitable renewable resources of the IndianEEZ |
| URI: | http://dyuthi.cusat.ac.in/purl/1007 |
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| Abstract: | The mangroves of Kerala are fast disappearing due to developmental activities.There are very few studies conducted in the chemical aspects of these ecosystems.The main objective of this study is to assess the spatial and seasonal variation of hydrographical as well as nutrients in mangrove ecosystems along Kerala coast. Five sampling sites least intervened by industries were selected for the study. Sampling was done for a period of six months in monthly intervals. A monsoonal hike of dissolved nutrients was observed in all ecosystems except in the constructed mangrove wetland. The constructed wetland exhibited a different hydrography and nutrient level in all seasons. The mangrove forest in this area consists of the species Bruguiera gymnorrhiza which has been planted since forty years. |
| Description: | Journal of Wetlands Ecology, (2009) Vol. 3, pp 32-42 |
| URI: | http://dyuthi.cusat.ac.in/purl/4604 |
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| Seasonal Variab ... Coast Of Kerala, India.pdf | (259.4Kb) |
| Abstract: | The SST convection relation over tropical ocean and its impact on the South Asian monsoon is the first part of this thesis. Understanding the complicated relation between SST and convection is important for better prediction of the variability of the Indian monsoon in subseasonal, seasonal, interannual, and longer time scales. Improved global data sets from satellite scatterometer observations of SST, precipitation and refined reanalysis of global wind fields have made it possible to do a comprehensive study of the SST convection relation. Interaction of the monsoon and Indian ocean has been discussed. A coupled feedback process between SST and the Active-Break cycle of the Asian summer monsoon is a central theme of the thesis. The relation between SST and convection is very important in the field of numerical modeling of tropical rainfall. It is well known that models generally do very well simulating rainfall in areas of tropical convergence zones but are found unable to do satisfactory simulation in the monsoon areas. Thus in this study we critically examined the different mechanisms of generation of deep convection over these two distinct regions.The study reported in chapter 3 has shown that SST - convection relation over the warm pool regions of Indian and west Pacific oceans (monsoon areas) is in such a way that convection increases with SST in the SST range 26-29 C and for SST higher than 29-30 C convection decreases with increase of SST (it is called Waliser type). It is found that convection is induced in areas with SST gradients in the warm pool areas of Indian and west Pacific oceans. Once deep convection is initiated in the south of the warmest region of warm pool, the deep tropospheric heating by the latent heat released in the convective clouds produces strong low level wind fields (Low level Jet - LLJ) on the equatorward side of the warm pool and both the convection and wind are found to grow through a positive feedback process. Thus SST through its gradient acts only as an initiator of convection. The central region of the warm pool has very small SST gradients and large values of convection are associated with the cyclonic vorticity of the LLJ in the atmospheric boundary layer. The conditionally unstable atmosphere in the tropics is favorable for the production of deep convective clouds. |
| Description: | Department of Atmospheric Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2763 |
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| Dyuthi-T0786.pdf | (49.89Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/742 |
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| Padma Nambisan,Seaweed biotechnology,1999.PDF | (5.195Mb) |
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