| Abstract: | In this thesis T-policy is implemented to the inventory system with random lead time and also repair in the reliability of k-out-of-n system. Inventory system may be considered as the system of keeping records of the amounts of commodities in stock. Reliability is defined as the ability of an entity to perform a required function under given conditions for a given time interval. It is measured by the probability that an entity E can perform a required function under given conditions for the time interval. In this thesis considered k-out-of-n system with repair and two modes of service under T-policy. In this case first server is available always and second server is activated on elapse of T time units. The lead time is exponentially distributed with parameter and T is exponentially distributed with parameter from the epoch at which it was inactivated after completion of repair of all failed units in the previous cycle, or the moment n-k failed units accumulate. The repaired units are assumed to be as good as new. In this study , three different situations, ie; cold system, warm system and hot system. A k-out-of-n system is called cold, warm or hot according as the functional units do not fail, fail at a lower rate or fail at the same rate when system is shown as that when it is up. |
| URI: | http://dyuthi.cusat.ac.in/purl/41 |
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| Dyuthi-T0308.pdf | (3.217Mb) |
| Abstract: | This thesis Entitled Trace metal speciation in the cochin estuary.Natural waters provide a favourable environment for speciation studies because of the prevailing variable chemical matrix and the variety of metal forms which may exist there.An estuary is a mixing zone of riverine and oceanic waters with widely varying compositions where end members interact both physically and chemically. The trace element chemistry in the estuarine environment has been an area of considerable research in the past decades. The trace metal distribution in the Cochin estuary is considerably influenced by the tropical features of the location and by human activities. The lower Periyar river and the Cochin estuary have been particularly selected for this investigation in view of the impact of trace metals on the estuarine ecosystem as well as in attempt quantify the phenomenon of metal speciation in the waters of a tropical coastal plain waterbody. If the concentration in the water media is very low, then, many of the fractions that could be estimated by speciation schemes for metals will fall below the detection limits, a factor which is undesirable.The study would also delineate the features of metal speciation which modify the chemical regime of ionic elements that traverse natural boundaries in aquatic environments, especally in those tropical areas prone to multivariate geographical settings. |
| Description: | Chemical Oceanography Division, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3117 |
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| Dyuthi-T1091.pdf | (4.663Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1850 |
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| Dyuthi-T0320.pdf | (8.306Mb) |
| Abstract: | There are various studies conducted on transformational leadership and learning organization. The term gets more importance in current scenario as the technological advancement and many other factors made organization unsustainable without learning culture. The objective of this study was to identify relationship between transformational leadership and learning organizations. The study was conducted in 27 organizations inside Kerala and the tools used for the study are Multifactor leadership questionnaire (MLQ) 21 items by Bernad M Bass and B J Avolio and the Dimensions of learning organizations questionnaire (DLOQ) 43 items by Watkins and Marsick. The study has used confirmatory factor analysis, one way ANOVA, Pearson correlation analysis and Canonical discriminant function analysis for deriving the results. The result of this research proves that, there is a significant relationship between transformational leadership and learning organization. There is a significant positive impact of the factors of Transformational leadership i.e. idealized influence, inspirational motivation, intellectual stimulation, individual consideration, contingent reward, management by exception and laissez faire leadership in discriminating high, medium and low learning organization. |
| URI: | http://dyuthi.cusat.ac.in/purl/5261 |
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| Dyuthi T-2297.pdf | (2.291Mb) |
| Abstract: | Catalysis is a mature field with extensive practical applications in today's society.indeed,the catalysis of petroleum refining,fine chemical synthesis and emission control demands the production of catalysts in bulk quantities.Future improvement of these well established processes is likely to be incremental.On the other hand,the continuous demand for new products will require additional novel and innovative processes.The need for pollution abatement and prevention also imposes new demands on catalysis, and new processes are periodically advanced for the control of emission of gases as well as for remediation processes such as the cleaning of underground waters. The number of problems where catalysis can have a big impact is constantly growing.In general,science stimulated by the technology has enriched the field of catalysis in a way that has had broad and lasting value.The thesis"Transition metal and rare earth metal modified sol-gel titania: a versatile catalyst for organic transformations" accounts the preparation and characterization studies of both transition metals and rare earth metals modified sol-gel titania and its applications in industrially useful organic reactions. |
| Description: | Department of Applied Chemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2376 |
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| Dyuthi-T0648.pdf | (13.53Mb) |
| Abstract: | Thiosemicarbazones have recently attracted considerable attention due to their ability to form tridentate chelates with transition metal ions through either two nitrogen and sulfur atoms, N–N–S or oxygen, nitrogen and sulfur atoms, O–N–S. Considerable interest in thiosemicarbazones and their transition metal complexes has also grown in the areas of biology and chemistry due to biological activities such as antitumoral, fungicidal, bactericidal, antiviral and nonlinear optical properties. They have been used for metal analyses, for device applications related to telecommunications, optical computing, storage and information processing.The versatile applications of metal complexes of thiosemicarbazones in various fields prompted us to synthesize the tridentate NNS-donor thiosemicarbazones and their metal complexes. As a part of our studies on transition metal complexes with these ligands, the researcher undertook the current work with the following objectives. 1. To synthesize and physico-chemically characterize the following thiosemicarbazone ligands: a. Di-2-pyridyl ketone-N(4)-methyl thiosemicarbazone (HDpyMeTsc) b. Di-2-pyridyl ketone-N(4)-ethyl thiosemicarbazone (HDpyETsc) 2. To synthesize oxovanadium(IV), manganese(II), nickel(II), copper(II), zinc(II) and cadmium(II) complexes using the synthesized thiosemicarbazones as principal ligands and some anionic coligands. 3. To study the coordination modes of the ligands in metal complexes by using different physicochemical methods like partial elemental analysis, thermogravimetry and by different spectroscopic techniques. 4. To establish the structure of compounds by single crystal XRD studies |
| Description: | Department of Applied Chemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3267 |
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| Dyuthi-T1241.pdf | (4.892Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5203 |
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| Dyuthi T-2238.pdf | (14.24Mb) |
| Abstract: | Schiff base complexes of transition metal ions have played a significant role in coordination chemistry.The convenient route of synthesis and thermal stability of Schiff base complexes have contributed significantly for their possible applications in catalysis,biology,medicine and photonics.Significant variations in cataltytic activity with structure and type are observed for these complexes.The thesis deals with synthsis and characterization of transition metal complexes of quinoxaline based Schiff base ligands and their catalytic activity study.The Schiff bases synthesized in the present study are quinoxaline-2-carboxalidine-2-amino-5-methylphenol,3-hydroxyquinoxaline-2-carboxalidine-2-amino-5-methylphenol,quinoxaline-2-aminothiophenol.They provide great structural diversity during complexation.To the best of our knowledge, the transition metal complexes of quinoxaline based Schiff bases are poorly utilised in academic and industrial research. |
| Description: | Dept.of Applied Chemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2364 |
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| Dyuthi-T0636.pdf | (3.783Mb) |
| Abstract: | Metallo-organic chemistry,incorporating the frontiers of both inorganic and organic chemical aspects,is a topic of utility concern.The first exploration of coordinated metal complexes dates back to the ninettenth century,during the days of Alfred Werner.Thereafter,inorganic chemistry witnessed a great outflow of coordination compounds,with unique structural characteristics and diverse applicatons.The diversity in structures exhibited by the coordination complexes of multidentate ligands have led to their usage as sensors,models for enzyme mimetic centers,medicines etc.The liganda chosen are of prime importance in determining the properties of coordination compounds.Schiff bases are compounds obtained by the condensation of an aidehyde or ketone with an amine.The chemical properties of Schiff bases and their complexes are widely explored in recent years owing to their pharmacological activity,their catalytic activities and so on.On the other hand pseudohalides like azide and thiocyanate are versatile candidates for the construction of dimeric or polymeric complexes having excellent properties and diverse applications.So a combination of the Schiff bases and the pseudohalogens for the synthesis of metal complexes can bring about interesting results.An attempt into this area is the besis of this Ph.D theis. |
| Description: | Department of Applied Chemistry, Cochln University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2543 |
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| Dyuthi-T0687.pdf | (10.30Mb) |
| Abstract: | Coordination chemistry of pentadentate 2,6-diacetylpyridine bis(thiosemicarbazone) Schiff base ligands has been intensively studied due to the versatility of the molecular chain in order to obtain very different geometries as well as their broad therapeutic activity. Metal complexes of thiosemicarbazone with aldehydes and ketones have been widely reported. But there have been fewer reports on potential pentadentate bis(thiosemicarbazones) formed from 2,6-diacetylpyridine. Keeping these in view, we have synthesized four bis(thiosemicarbazone) systems with 2,6-diacetylpyridine. In the present work, the chelating behavior of bis(thiosemicarbazones) are studied, with the aim of investigating the influence of coordination exerts on their conformation and or configuration, in connection with the nature of the metal and of the counter ion. The selection of the 2,6-diacetylpyridine as the ketonic part was based on its capability to form polynuclear complexes with different coordination number. The doubled armed bis(thiosemicarbazones) can coordinate to a metal centre as dianionic ligand by losing its amide protons or it can coordinate as monoanionic ligand by losing its amide proton from one of the thiosemicarbazone moiety or it can also be coordinate as neutral ligand. Hence it is interesting to explore the coordinating capabilities of these ligands whether in neutral form or anionic form and to study the structural variations occurring in the ligands during complexation such as change in conformation. |
| Description: | Department of Applied Chemistry, Cochin university of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2750 |
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| Dyuthi-T0775.pdf | (3.751Mb) |
| Abstract: | The unusual coordination modes of semicarbazones when bound to metals, the wide applications and structural diversity of metal complexes of semicarbazones provoked us to synthesize and characterize the tridentate ONO and NNO-donor semicarbazones and their transition metal complexes. This work is focused on the studies on complexes of three N4-phenylsemicarbazones synthesized by changing the carbonyl compounds. This work is concerned with the studies of two new semicarbazones, 2- formylpyridine-N4-phenylsemicarbazone (HL1) and 3-ethoxysalicylaldehyde- N4-phenylsemicarbazone (H2L2) and a reported semicarbazone 2-benzoylpyridine-N4-phenylsemicarbazone (HL3) [29]. The compositions of these semicarbazones were determined by the CHN analyses and IR, UV and NMR spectral studies were used for the characterization of these compounds. The molecular structure of 3-ethoxysalicylaldehyde-N4-phenylsemicarbazone (H2L2) was obtained by single crystal X-ray diffraction studies. Also, we have synthesized Cu(II), Cd(II), Zn(II) and Ni(II) complexes of these three semicarbazones. The complexes were characterized by various spectroscopic techniques, magnetic and conductivity studies. We could isolate single crystals of some complexes of all metals suitable for X-ray diffraction studies. This thesis is divided into six chapters. |
| Description: | Department of Applied Chemistry, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3261 |
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| Dyuthi-T1235.pdf | (10.04Mb) |
| Abstract: | The work embodied in this thesis was carried out by the author in the Department of Applied Chemistry, CUSAT, Kochi, during the period 2009-2012. The thesis is an introduction to our attempts to evaluate the coordination behavior of some compounds of our interest. The biological activities of semicarbazones and their metal complexes have been an active area of research during the past years because of their significant role in naturally occurring biological systems. Tridentate NNO and ONO semicarbazone systems formed from heterocyclic and aromatic carbonyl compounds and their transition metal complexes are wellauthenticated compounds in this field and their synthesis, crystal structures and spectral studies are well desirable. Hence, we decided to develop a research program aimed at the syntheses, crystal structures and spectral studies of new N4- phenylsemicarbazones derived from 2-formylpyridine and 3-ethoxysalicylaldehyde and their transition metal complexes and new transition metal complexes of 2- benzoylpyridine-N4-phenylsemicarbazone. In addition to various physicochemical methods of analysis, single crystal X-ray diffraction studies were also used for the characterization of the complexes. |
| URI: | http://dyuthi.cusat.ac.in/purl/5113 |
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| Dyuthi-T 2178.pdf | (10.53Mb) |
| Abstract: | In the present work,the chelating behaviour of thiosemicarbazones of a heterocyclic diketone, 2,6-diacetylpyridine is studied,with the aim of investigating the influence coordination exerts on their conformation and /or configuration, in connection with the nature of the metal and of the counter ion.The various possibilities like unsubstitution,ring incorporation at terminal nitrogen and condensation of one of the ketone group alone have been tried for ligand selection.Mainly first row transition metals like manganese,iron,nickel,copper,zinc and cadmium are studied.Metals like cobalt also were studied but could not result in fruitful isolation of the compound due to solubility problems.Different spectroscopic and characterization techniques have been utilized to reveal the nature of the metal and the ligands in coordinated metal complex. |
| Description: | Department of Applied Chemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2790 |
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| Dyuthi-T0811.pdf | (6.089Mb) |
| Abstract: | Cashew is an important commodity traded across the continents and the world cashew industry is the livelihood of more than three million people worldwide, the majority of whom are womenfolk from the socially and economically backward community of the developing nations. Cashew tree was originally planted to prevent soil erosion and it was during the beginning of the 19th century that cashew kernels attained the status of a food item. Further, the cashew kernels attained the status of an international commodity with India exporting its first consignment of cashew kernels to U.S.A. in 1920. India was the first country to hit the world market with cashew as a commodity and it was she who pioneered cashew processing as an industry. For decades together India was enjoying a monopoly in the world cashew industry in the fields of raw nut production (cultivation), processing and the market share in the international trade. The liberalisation of international trade has brought in a big transition in the world of cashew. India started to benefit from the trade policy, that improved her supply positions of raw nuts from other producing countries, accelerated her growth in processing of raw nuts and exports of cashew kernels. On the other side, her domestic consumption started growing up that by the beginning of the new century, she emerged out as the world’s largest consumer of cashew kernels as well. |
| URI: | http://dyuthi.cusat.ac.in/purl/5106 |
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| Dyuthi-T 2172.pdf | (3.044Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/5164 |
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| Dyuthi-T2198.pdf | (9.513Mb) |
| Abstract: | The study documents the long-term trends in financial intermediation by the principal player in Kerala’s credit system i.e., banking. The process of financial intermediation by the banking system, involving mobilization of deposits from savers and disbursal of credit to investors, is considered to be crucial in the process of economic development. The objective of the study is to explore the interrelationship between financial intermediation and economic growth in Kerala. In order to pursue this objective, the study examine, the trends in intermediation by the banking system in Kerala over a long period, the trend and pattern of bank deposits and credit in the State and Kerala’s economic growth, the trend in the growth and performance of financial intermediaries like the All India Financial Institutions, the links between banking and economic variables, and the difference in the growth trends of banking and economic variables between Kerala and India and the probable reasons for the difference |
| URI: | http://dyuthi.cusat.ac.in/purl/100 |
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| Dyuthi-T0309.pdf | (6.923Mb) |
| Abstract: | The present work deals with the complexation of Schiff bases of aroylhydrazides with various transition metal ions. The hydrazone systems selected for study are capable of forming bridged polymeric structures which is one of the fascinating subjects in the crystal engineering of coordination polymers owing to their attractive new topologies and intriguing structural features. Complexation with metal ions like copper, manganese, vanadium, nickel, palladium, zinc and cadmium are tried. Various spectral techniques are employed for characterization. The structures of some complexes have been well established by single crystal X-ray diffraction studies.The work is presented in seven chapters and the last section deals with summary and conclusion. The studies reveal that the aroylhydrazone systems vary in their geometrical configuration depending on the substituents. The coordination modes of the ligands also differ upon chelating with metal ions. One of the hydrazone system selected for study proved that it could give rise to polymeric metal complexes. |
| Description: | Dept.of Applied Chemistry,Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/2992 |
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| Dyuthi-T0972.pdf | (9.698Mb) |
| Abstract: | This thesis entitled triterpenoids as biomarkers of mangrove organic matter in cochin estuarine system.Mangrove forests, known as rainforests of the sea are one of the most important coastal ecosystems in the world in terms of primary production and coastal protection.Estuaries, the important areas of world’s coastal zones link the carbon cycle of the oceans to the continents.Three mangrove ecosystems and three estuarine stations around Cochin region, southwest coast of India were selected for the present study. The thesis is divided into five chapters. Chapter 1 is the Introduction and it deals with the aim and scope of the present study. Chapter 2 is Materials and Methods. This chapter deals with the nature and general geographical features of the study area. It also contains the details of the sampling and analytical methodology.the present study. Chapter 3 is Geochemistry and it includes the seasonal and spatial variations of the geochemical parameters in the surface sediments.Chapter 4 is Biochemical Composition. It covers the biochemical composition of organic matter in the surface sediments to examine the quality and quantity of organic matter.Chapter 5, Triterpenoid Biomarkers in Sediments, characterize the organic matter in the sediments of the mangrove and estuarine ecosystems under study, to assess the possible sources with the help of triterpenoid biomarkers along with other lipid biomarkers. |
| Description: | Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology |
| URI: | http://dyuthi.cusat.ac.in/purl/3104 |
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| Dyuthi-T1078.pdf | (6.312Mb) |
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