Soloman, M A; Dr. Philip, Kurian(Cochin University of Science & Technology, July , 2002)
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Abstract:
In the present study the preparation and characterisation of rubber ferrite
composites (RFC) containing barium ferrite (BaF) and strontium ferrite (SrF) have
been dealt with. The incorporation of the hard ferrites into natural and nitrile rubber
was carried out according to a specific recipe for various loadings of magnetic
fillers. For this, the ferrite materials namely barium ferrite and strontium ferrite
having the general formula MO6Fe2O3 have been prepared by the conventional
ceramic techniques. After characterisation they were incorporated into the natural
and nitrile rubber matrix by mechanical method. Carbon black was also incorporated at different loading into the rubber ferrite composites to study its
effect on various properties. The cure characteristics, mechanical, dielectric and
magnetic properties of these composites were evaluated. The ac electrical
conductivity of both the ceramic ferrites and rubber ferrite composites were also
calculated using a simple relation. The investigations revealed that the rubber ferrite composites with the
required dielectric and magnetic properties can be obtained by the incorporation of
ferrite fillers into the rubber matrix, without compromising much on the
processability and mechanical properties.
Description:
Department of Polymer Science and Rubber Technology, Cochin
University of Science and Technology
Padmaja, K; Dr.Mary,Joseph T(Cochin University of Science and Technology, September , 2005)
[+]
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Abstract:
The thesis entitled An Evaluation of Primary Health Care System in Kerala. The present study is intended to examine the working of primary health care system and its impact on the health status of people. The hypothesis tested in the thesis includes,
a. The changes in the health profile require reallocation of resources of primary health care system,
b. Rate of utilization depends on the quality of services provided by primary health centers, and c. There is a significant decline in the operational efficiency of the primary health care system.
The major elements of primary health care stated in the report of AlmaAta International Conference on Primary Health Care (WHO, 1994)” is studied on the basis of the classification of the elements in to three: Preventive, Promotive, and Curative measures. Preventive measures include Maternal and Child Health Care including family Planning. Provision of water and sanitation is reviewed under promotive measures. Curative measures are studied using the
disease profile of the study area. Collection of primary data was done through a sample survey, using pre-tested interview schedule of households of the study area. Multi stage random sampling design was used for selecting the sample. The design of the present study is both descriptive and analytical in nature. As far as the analytical tools are concerned, growth index, percentages, ratios, rates, time series analysis, analysis of variance, chi square test, Z test
were used for analyzing the data. Present study revealed that no one in these areas was covered under any type of health insurance. Conclusion states that considering the present changes in the health profile, traditional pattern of resource allocation should be altered to meet the urgent health care needs of the people. Preventive and promotive measures like health education for
giving awareness among people to change health habits, diet pattern, life style etc. are to be developed. Proper diagnosis and treatment of the disease at the beginning of the stage itself may help to cure majority of disease. For that, Public health policy must ensure the primary health care as enunciated at Alma- Ata international Conference. At the same time Public health is not to be treated as the sole responsibility of the government. Active community participation is an essential means to attain the goals.
Description:
School of Management Studies, Cochin University of Science and Technology,
Sindhu, M.C; Dr. A. Ramachandran(Cochin University of Science and Technology, February , 2015)
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Abstract:
Transport of live aquatic organisms which is more than a century old,
perhaps started in the 1870's (Norris et al, 1960). Live fish transportation is
an essential practice in aquaculture particularly in rural areas of developing
countries representing the only means of supplying fry to small scale aqua
culturists (Taylor and Ross, 1988). Very often, large numbers of fry,
fingerlings, juveniles and adult fish are being transported from the hatchery
to fish farms, fish farms to market, processors and consumers. Live fish
command large economic importance in the fresh fish market than dead and
iced fish. Medina Pizzali (2001) observed that live fish in the Kolkata market
was usually sold at higher prices than dead fish and most consumers were
prepared to pay premium prices for live fish, which is considered as the best
guarantee of freshness, quality, and intrinsic characteristics of its flesh (better
texture and delicate flavour) in comparison with fresh/chilled seafood.
Various government and private agencies undertake transport of live fish for
commercial live fish market or for artificial propagation of game
Ambili, V; Narayana, A C(Cochin University of Science and Technology, October , 2010)
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Abstract:
Drainage basins are durable geomorphic features that provide insights into the long term evolution of the landscape. River basin geometry develop response to the nature and distribution of uplift and subsidence, the spatial arrangement of lineaments (faults and joints), the relative resistance of different rock types and to climatically influenced hydrological parameters . For developing a drainage basin evolution history, it is necessary to understand physiography, drainage patterns, geomorphic features and its structural control and erosion status. The present study records evidences for active tectonic activities which were found to be responsible for the present day geomorphic set up of the study area since the Western Ghat evolution. A model was developed to explain the evolution of Chaliar River drainage basin based on detailed interpretation of morphometry and genesis of landforms with special emphasis on tectonic geomorphic indices and markers.
Description:
Department of Marine Geology and Geophysics, Cochin University of Science and Technology
Saleena, K B; Dr. Gopalakrishnan, N S(Cochin University of Science and Technology, October 19, 2011)
[+]
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Abstract:
This thesis entitled Exceptions and limitations to intellectual property rights with special reference to patent and copyright law.The study on the limitations and exceptions to copyright and patent was mainly characterized by its diversity and flexibility. The unique feature of limited monopoly appended to intellectual property was always a matter of wide controversy.The historical analysis substantiated this instrumentalist philosophy of intellectual property.the study from a legal space characterized by diversity and flexibility and end up in that legal space being characterized by homogeneity and standardization. The issue of flexibility and restrictiveness in the context of TRIPS is the next challenging task. Before devising flexibility to TST, the question to be answered is whether such a mechanism is desirable in the context of TRIPS.In conclusion it is submitted to reorient the intellectual property framework in the context of the noble public interest objectives.
Description:
School of Legal Studies, Cochin University of Science and Technology.
Sinu, C R; Vijay, Nair, G; Radhakrishnan, K V(Cochin University of Science And Technology, November 22, 2014)
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Abstract:
The thesis entitled “Exploration of Novel Organic Reactions Catalyzed by
Nucleophilic Heterocyclic Carbenes (NHCs)” embodies the results of the
investigations carried out to explore the synthetic potential of N–heterocyclic carbenes
(NHCs) as organocatalyst towards various electrophiles for the synthesis of heterocyclic
and carbocyclic systems. Recent investigations in the generation of homoenolates by the
addition of NHCs to conjugated aldehydes have made it possible to study the reactivity of
this unique three carbon synthon.
Krishnan Kartha, K; Dr. Ajayaghosh, A(Cochin University Of Science And Technology, January 8, 2014)
[+]
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Abstract:
Gelation provides a unique medium, which often induces
organization of molecules resulting in the modulation of their
optical, morphological and electronic properties thereby opening a
new world of fascinating materials with interesting physical
properties at nano- meso- and macroscopic levels. Supramolecular
gels based on linear π-systems have attracted much attention due to
their inherent optical and electronic properties which find
application in organic electronics, light harvesting and sensing. They
exhibit reversible properties due to the dynamic nature of noncovalent
forces. As a result, studies on such soft materials are
currently a topic of great interest. Recently, researchers are actively
involved in the development of sensors and stimuli-responsive
materials based on self-assembled π-systems, which are also called
smart materials.
The present thesis is divided into four chapters
Description:
Photosciences and Photonics
Chemical Sciences and Technology Division
CSIR-National Institute for Interdisciplinary Science and
Technology (CSIR-NIIST), Trivandrum
Hector J,Thayil Kochukunnel; Arunachalam, P(Department of Applied Economics, 2006)
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Abstract:
The study was motivated by the need to understand factors that guide the software exports and competitiveness, both positively and negatively. The influence of one factor or another upon the export competitiveness is to be understood in great depth, which is necessary to find out the industry’s sustainability. India is being emulated as an example for the success strategy in software development and exports. India’s software industry is hailed as one of the globally competitive software industry in the world. The major objectives are to model the growth pattern of exports and domestic sales of software and services of India and to find out the factors influencing the growth pattern of software industry in India. The thesis compare the growth pattern of software industry of India with respect to that of Ireland and Israel and to critically of various problems faced by software industry and export in India and to model the variables of competitiveness of emerging software producing nations
Francis,C A; Dr.Ranganathan, N(Cochin University of Science and Technology, August 6, 1991)
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Abstract:
The main aim of this study is to examine the deficiencies of the export development process and strategy in India and, to suggest, in the light of the findings of the above, measures for improvement. The marine products industry has been chosen as a case for a detailed investigation. The researcher conducts an evaluative study on the export potential for India’s marine products and trends in the international market for marine products. The thesis tries to identify the major hurdles in increasing exports of marine products from India. The evaluation of the adequacy and effectiveness of the measures taken to promote marine products exports is also undertaken
Description:
School of Management Studies, Cochin
University of Science & Technology
Muhamed Kutty, K B; Dr.Chandrasekharan, N S(Cochin University of Science and Technology, November 14, 1988)
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Abstract:
This thesis is a study in sales tax law, a study on the triple concept of export, import and inters—State sales. It is in seventeen chapters spread in five parts. The introductory is an overview. It presents the thematic thrust of what follows. Part two deals with incidence of sales tax on export and import and the scope of exemption. Part three focuses attention on the various dimensions of the problem of inter—State sale. Part four is an inquiry into parliamentary control on taxes over sales and purchases and highlights inter—State and intra-State implications of discriminatory tax. Part five contains the results of empirical study and the general conclusions of the thesis. In the past no attempt has been made to analyse on identical lines the problems dealt with in this thesis
Description:
Department of Law, Cochin University of Science and
Technology
Ibrahim, Y C; Arunachalam, P(Cochin University Of Science And Technology, February 25, 2015)
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Abstract:
Export has assumed an important place in the development of
any country and considered as the engine of economic growth. India
requires huge amount of foreign exchange for its essential import
and for achieving rapid growth. Millions of job opportunities have to
be created to utilise the youth for nation building. Even though the
country has different sources of foreign exchange, export earning is
the safe way of obtaining it in the long run. Export of high valued
traditional products not only gives foreign exchange, but also
employment to large number of people. Spices are the traditional
products of India whose production process is highly intensive in
semi and unskilled labour, and high domestic and foreign market
prices compared to other traditional products. The new world trade
scenario with the establishment of WTO has affected India’s spices
export considerably.
The study examines the export performance of Indian spices in
the WTO regime taking the export of major spices from 1985 to 2013
using the growth of export, trend and instability in growth rate,
changes in the composition and direction of spices, export
performance ratio and the prospects of spices in earning foreign
exchange during the WTO period and Pre-WTO period.
The analysis reveals that the overall performance of Indian
spices exports during the WTO regime are satisfactory. Export
volume and value increased much during this period. But the
decrease in market share of spices export during the WTO period
reflects that, the favourable conditions in the international market
are not exploited by India. High Revealed Comparative Advantage
(RCA) and Value Elasticity (EV) of major spices amidst the low export
shares shows that export performance of Indian spices during the
WTO regime was not mainly affected by external demand factors as
suggested by Ragnar Nurkse in his Demand Deficiency Thesis, but
because of internal supply factors as suggested in Supply Deficiency
Thesis, (supported by K.S Dhinsha, Dacosta, Goddamwar,etc.). But
the fluctuations of export during the recession and prosperity periods
show that external demand is also a determinant of Indian spices
export. From this one can conclude that both the domestic supply
factors and foreign demand factors influence the export performance
of Indian spices. The long term performance of Indian spices exports
are mainly influenced by domestic supply factors as suggested by
Supply Deficiency Thesis and short term performance is mostly
influenced by external demand factors as suggested by Demand
Deficiency Thesis.
Sindu,T K; Sankaran, P G(COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY, December , 2002)
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Abstract:
In the present environment, industry should provide the products of high quality. Quality of products is judged by the period of time they can successfully perform their intended functions without failure. The cause of the failures can be ascertained through life testing experiments and the times to failure due to different cause are likely to follow different distributions. Knowledge of this distribution is essential to eliminate causes of failures and thereby to improve the quality and the reliability of products. The main accomplishment expected to the study is to develop statistical tools that could facilitate solution to lifetime data arising in such and similar contexts
Madhu, K M; Dr.Chandrasekaran,M(Cochin University of Science and Technology, April , 2007)
[+]
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Abstract:
The beta-glucosidase enzyme purified from the marine fungus, Aspergillus
sydowii BTMFS 55 showed a good yield of enzyme production under solid state
fermentation. The statistical optimization of the media components revealed that
moisture content, concentration of peptone and inoculum are the major parameters
which supported the maximal enzyme production. The purified enzyme showed low
pH activity and stability, glucose tolerance and activation by ethanol. It could produce
ethanol from wheat bran and rice straw by simultaneous saccharification and
fermentation with yeast.The glucosidase purified from Aspergillus sydowii BTMFS 55
shows great potential for several biotechnological applications such as the production
of bio-ethanol from agricultural biomass and improvement in the aromatic character
of wines and fruit juices through the hydrolysis of flavour glucosidic precursors.
There is immense scope for the application of this marine fungus in the biofuel
production besides in other industries provided further studies are pursued in
exploiting this enzyme and the organism particularly scale up studies with respect to
application. There is also ample scope for cloning of the gene encoding beta-glucosidase
in domesticated hosts such as Pichia pastoris or S. cerevisiae that can produce ethanol
directly from cellulosic biomass.
Description:
Department of Biotechnology,
Cochin University of Science and Technology
Anas, A; Bright Singh, I S(Centre for Fish Disease Diagnosis and Management, School of Environmental Studies, 2005)
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Abstract:
Present work is aimed at development of an appropriate microbial technology for protection of larvae of macrobrachium rosenbergii from disease and to increase survival rate in hatcheries. Application of immunostimulants to activate the immune system of cultured animals against pathogen is the widely accepted alternative to antibiotics in aquaculture. The most important immunostimulant is glucan. Therefore a research programme entitled as extraction of glucan from Acremonium diospyri and its application in macrobrachium rosenbergii larval rearing system along with bacterians as microspheres. The main objectives of the study are development of aquaculture grade glucan from acremonium diospyri, microencapsulated drug delivery system for the larvae of M. rosenbergii and microencapsulated glucan with bacterian preparation for the enhanced production of M. rosenbergii in larval rearing system. Based on the results of field trials microencapsulated glucan with bacterin preparation, it is concluded that the microencapsulated preparation at a concentration of 25g per million larvae once in seven days will enhance the production and quality seed of M. rosenbergii.
Rajesh, M; Dr.Nampoori,V P N(Cochin University of Science & Technology, July , 2006)
[+]
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Abstract:
The thesis presented the fabrication and characterisation of
polymer optical fibers in their applications as optical amplifier and smart sensors.Optical polymers such as PMMA are found to be a very good host material due
to their ability to incorporate very high concentration of optical gain media like
fluorescent dyes and rare earth compounds. High power and high gain optical
amplification in organic dye-doped polymer optical fibers is possible due to
extremely large emission cross sections of oyes. Dye doped (Rhodamine 6G)
optical fibers were fabricated by using indigenously developed polymer optical
fiber drawing tower. Loss characterization of drawn dye doped fibers was carried
out using side illumination technique. The advantage of the above technique is
that it is a nondestructive method and can also be used for studying the
uniformity in fiber diameter and doping. Sensitivity of the undoped polymer
fibers to temperature and microbending were also studied in its application in
smart sensors.Optical amplification studies using the dye doped polymer optical fibers were
carried out and found that an amplification of l8dB could be achieved using a
very short fiber of length lOcm. Studies were carried out in fibers with different
dye concentrations and diameter and it was observed that gain stability was
achieved at relatively high dye concentrations irrespective of the fiber diameter.Due to their large diameter, large numerical aperture, flexibility and geometrical
versatility of polymer optical fibers it has a wide range of applications in the field
of optical sensing. Just as in the case of conventional silica based fiber optic
sensors, sensing techniques like evanescent wave, grating and other intensity
modulation schemes can also be efficiently utilized in the case of POF based
sensors. Since polymer optical fibers have very low Young's modulus when
compared to glass fibers, it can be utilized for sensing mechanical stress and
strain efficiently in comparison with its counterpart. Fiber optic sensors have
proved themselves as efficient and reliable devices to sense various parameters
like aging, crack formation, weathering in civil structures. A similar type of study
was carried out to find the setting characteristics of cement paste used for
constructing civil structures. It was found that the measurements made by using
fiber optic sensors are far more superior than that carried out by conventional
methods. More over,POF based sensors were found to have more sensitivity as
well.
Description:
International School of Photonics,
Cochin University of Science & Technology
Samuel Varghese, K; Dr.Nampoori,V P N; Dr.Girijavallabhan,C P(Cochin University of Science and Technology, December , 2008)
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Abstract:
This Thesis deals with the fabrication and characterization of novel all-fiber components for access networks. All fiber components offer distinctive advantages due to low forward and backward losses, epoxy free optical path and high power handling. A novel fabrication method for monolithic 1x4 couplers, which are vital components in distributed passive optical networks, is realized. The fabrication method differs from conventional structures with a symmetric coupling profile and hence offers ultra wideband performance and easy process control. New structure for 1x4 couplers, by fusing five fibers is proposed to achieve high uniformity, which gives equivalent uniformity performance to 1x4 planar lightwave splitters, isolation in fused fiber WDM is improved with integration of long period gratings. Packaging techniques of fused couplers are analyzed for long term stability.
Description:
International School of Photonics, Cochin University of Science and Technology
Tintu, R; Dr. Sheenu, Thomas(Cochin University of Science and Technology, June , 2011)
[+]
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Abstract:
In this context,in search of new materials based on chalcogenide glasses,we have developed a novel technique for fabrication of chalcogenide nano composites which are presented in this theis.The techniques includes the dissolution of bulk chalcogenide glasses in amine solvent.This solution casting method allows to retain the attractive optical properties of chalcogenide glasses enabling new fabrication routes for realization of large area thick-thin films with less cost. Chalcogenide glass fiber geometry opens new possibilities for a large number of applications in optics,like remote temperature measurements ,CO2 laser power delivery, and optical sensing and single mode propagation of IR light.We have fabricated new optical polymer fibers doped with chalcogenide glasses which can be used for many optical applications.The present thesis also describes the structural,thermal and optical characterization of certain chalocogenide based materials prepared for different methods and its applications.
Description:
International School of Photonics, Cochin University of Science and Technology
Beena,Mary John; Sudha Kartha, C(Department of Physics, January , 2008)
[+]
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Abstract:
Holographic technology is at the dawn of quick evolution in various new
areas including holographic data storage, holographic optical elements, artificial
intelligence, optical interconnects, optical correlators, commerce, medical practice,
holographic weapon sight, night vision goggles and games etc. One of the major
obstacles for the success of holographic technology to a large extent is the lack of
suitable recording medium.
Compared with other holographic materials such as dichromated gelatin
and silver halide emulsions, photopolymers have the great advantage of recording
and reading holograms in real time and the spectral sensitivity could be easily
shifted to the type of recording laser used by simply changing the sensitizing dye.
Also these materials possess characteristics such as good light sensitivity, real
time image development, large dynamic range, good optical properties, format
flexibility, and low cost. This thesis describes the attempts made to fabricate
highly economic photopolymer films for various holographic applications.
In the present work, Poly (vinyl alcohol) (PVA) and poly (vinyl chloride)
(PVC) are selected as the host polymer matrices and methylene blue (MB) is used
as the photosensitizing dye. The films were fabricated using gravity settling
method. No chemical treatment or pre/post exposures were applied to the films.
As the outcome of the work, photopolymer films with more than 70% efficiency, a
permanent recording material which required no fixing process, a reusable
recording material etc. were fabricated.
Sheeba, M; Dr. Radhakrishnan, P(Cochin University of Science and Technology, May 22, 2008)
[+]
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Abstract:
Although the main application of optical fibers are in the field of
telecommunication, optical fiber based sensors of various designs are
becoming valuable devices for wide industrial applications. The
advantages of optical fiber-based sensors include high sensitivity,
insensitivity to electromagnetic radiation; spark free, light weight and
minimal intrusiveness due to their relatively small size and deployment in
harsh and hostile environments. It has been proved that POI-7 based
sensors can be employed to detect a great variety of parameters including
temperature, humidity, pressure, refractive index etc.
The proposed thesis presented in six chapters deals with the work carried
on dye doped and undoped POF for photonic device applications such as
amplifier, laser and sensor
Description:
International School of Photonics
Cochin University of Science and Technology
Varkey,K P; Dr.Vijayakumar, K P(COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY, August , 1999)
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Abstract:
The study on the fabrication and characterization of spray pyrolysed cadmium sulphide homojunction solar cells. As an alternative to the conventional energy source, the PV technology has to be improved. Study about the factors affecting the performance of the existing solar cells and this will result in the enhancement of efficiency of the cells. At the same time it is equally important to have R&D works on developing new photovoltaic devices and processes which are less expensive for large scale production. CdS is an important binary compound semiconductor, which is very useful in the field of photovoltaics. It is very easy to prepare large area CdS thin films. In order to fabricate thin film homojunction cadmium sulphide cells, prepared and characterized SnO2 thin film as the lower electrode, p-CdS as the active layer and n-CdS as window layer. Cadmium material used for the fabrication of homojunction solar cells is highly toxic. The major damage due to continued exposure to low levels of cadmium are on the kidneys, lungs and bones. The real advantage of spray pyrolysis process is that there is no emission of any toxic gases during the deposition. Very low concentration of the chemicals is needed in this process. The risk involved from this material is very low, though they are toxic. On large scale usage it may become necessary that the cells after their life, should be bought back by the companies to retrieve chemicals like cadmium. This will reduce environmental problem and also the material wastage
Sebastian, P J; Dr.Sathianandan, K(Cochin University Of Science And Technology, November 25, 1981)
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Abstract:
Eventhough a large number of schemes have been proposed and develoned for N9 laser ouined dye lasers the
relatively low efficiency compelled the scientists to
device new methods to improve the system efficiencs.
Energy transfer mechanism has been shown to he a convenien
tool for the enhancement of efficiency of dye lasers. Th
p resent work covers a detailed study of the performance
characteristics of a N2 laser pumped dye laser in the con—
ventional mode and also, when pumped by the energy transfer
mechanism. For .th.e present investigations a dye laser
pumped by a'N2 laser (A4200 kw peak power) was fabricated.
The grating at grazing incidence was used as the beam expanding
device; A t its best performance the system was
giving an output peak power of l5 kW for a 5 X lC"3H/l Rh—€
solution in methanol. T he conversion efficiency was 7.5;
The output beam was having 3 divergence of 2 mrad and bandwidth
o.9 A. Suitable modifications were suggested for
obtaining better conversion efficiency and bandwidth.
Description:
Department of Physics,
Cochin University Of Science And Technology
Jayaraj, M K; Dr.Girijavallabhan,C P(Cochin University of Science and Technology, June 20, 1988)
[+]
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Abstract:
This thesis contains the author's work in preparing efficient EL phosphors, the details of fabrication of low voltage operated thin film EL (TFEL) devices and DC TFEL devices. Some of the important work presented here are related to the white light emitting ZnS:Cu,Pr,Cl phosphor which can be colour tuned by changing the excitation frequency, observation of energy transfer from Cu/Ag ions to rare earth ions in ZnS:(Cu/Ag), RE,Cl phosphors, development of TFEL device which can be operated below 50V, optimization of the device parameters for long life, high brightness in terms of the active and insulating layer thicknesses, observation of dependence of threshold voltage for the onset of emission on frequency of excitation when a novel dielectric Eu2O3 film was used as insulator and the devices with multicolor emission using ZnS doped with rare earth as active layer. Characterization based on other devices based on ZnS:Sm, ZnS:Pr, ZnS:Dy and their emission characteristics are also illustrated
Description:
Department of Physics, Cochin University of Science and Technology
Sareena, John; Dr.Girish Kumar, K(Cochin University of Science and Technology, December , 2007)
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Abstract:
Potentiometric chemical sensors,an important class of electro-chemical sensors are widely used in pharmaceutical analysis because of its inherent advantages.The present study was aimed at fabrication of potentiometric sensors for the drugs mebendazole,pefloxacin,ambroxol,sildenafil citrate,dextro-methorphan and tetracycline.A total of 18 sensors have been developed for the determination of theses drugs.The major step in the fabrication of the sensor was the preparation of the ion association.Two types of sensors viz:PVC membrane sensor and carbon paste electode (CPE) were fabricated.The response characteristics of the different sensors fabricated were studied.Various response parameters studied include response time,selectivity and the effect of pH.The developed sensors were also employed for the determination of the drugs in pharmaceutical formulations and also for the recovery of the drug from urine samples.The selectivity studies reveal that the developed sensors are highly selective to the drug even in prescence of foreign ions.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Sindhu, Issac; Dr.Girish Kumar, K(Cochin University of Science & Technology, February , 2011)
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Abstract:
Voltammetric sensors are an important class of electrochemical sensors in which the analytical information is obtained from the measurement of current obtained as a result of electrochemical oxidation/reduction.This current is proportional to the concentration of the analyte.Chemically modified electrodes(CMEs) have great significance as important analytical tools for the electrochemical determination of pharmaceuticals.The modification of electrode results in efficient determination of electro-active biomolecules at very lower potential without its major interferences.The operation mechanism of CMEs depends on the properties of the modifier materials that are used to promote selectivity towards the target analytes.Modified electrodes can be prepared by deposition of various compounds such as organic compounds ,conducting polymers,metal oxides,etc. on the various electrode surfaces.The thesis presents the development ,electrochemical characterization and analytical application studies of eight voltammetric sensors developed for six drugs viz.,Ambroxol,Sulfamethoxazole,PAM Chloride, Lamivudine,Metronidazole and Nimesulide.The modification techniques adopted as part of the present work include Multiwalled Carbon Nanotube(MWCNT) based modification.Electropolymerisation and Gold Nanoparticle (AuNP) based modifications.
Description:
Dept.of Applied Chemistry,Cochin University of Science & Technology
Remalakshmy,Poduval; Girish Kumar,K(Department of applied chemistry, 2006)
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Abstract:
In this study Fabrication of Potentiometric sensors for the determination of certain metal ions, presents the synthesis and characterization of seven ionophores, their use in the fabrication of potentiometric sensors and the results and discussion of fourteen sensors developed for the determination of five transition metal ions. As part of the present investigations a total of fourteen potentiometric sensors have been developed and fabricated. A three fold approach has been taken in developing he sensors, PVC plasticized membrane sensor, carbon paste electrode and chemically modified carbon paste electrode. All the sensors are highly useful in the determination of metal ions such as manganese, nickel, copper, mercury and lead. A through analytical study has been carried out with respect to each other developed. Based on these studies, optimum conditions have been developed for the quantitative determinations of the selected metal ions using the sensors. Systematic application studies have also been carried out for all the developed sensors and the results revealed that the presently developed sensors are far superior than most of the sensors reported.
Beena, S; Dr.Girish Kumar, K(Cochin University of Science and Technology, May , 2010)
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Abstract:
In many fields such as earth science biology, environment and electronics, the knowledge about elemental distributions and chemical speciation is important. The determination of metal levels especially the toxic ones both in the environment and in biological materials are increasingly demanded by the society.Ion selective sensors have become one of the most effective ad powerful means for analytical scientists for the trace level monitoring of metal ions. The wide range of applications ,low material requirements and simplicity of analytical procedure have not only brought ion-selective electrodes in to the lime light of analytical chemistry,but have promoted their use as tools for physiologists,medical researchers,biologists,geologists,environmental protection specialists etc.Potentiometric ion-selective sensors have been developed for the determination of lanthanide ions such as La3+,Nd3+,Pr3+,Sm3+, and Gd3+.The sensors fabricated include both PVC membrane sensor and chemically modified carbon paste sensor. A set of 10 sensors have been developed. The response parameters of all the sensors have been studied and the sensors were applied as an indicator electrode in the potentiometric titration and for the determination of metal ions in real samples.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Sunitha, Sabastin; Dr. M. Kailasnath(Cochin University of Science and Technology, June 12, 2015)
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Abstract:
Polymer Optical Fibers have occupied historically a place for large core flexible fibers operating in short distances. In addition to their practical passive application in short-haul communication they constitute a potential research field as active devices with organic dopants. Organic dyes are preferred as dopants over organic semiconductors due to their higher optical cross section. Thus organic dyes as gain media in a polymer fiber is used to develop efficient and narrow laser sources with a tunability throughout the visible region or optical amplifier with high gain. Dyes incorporated in fiber form has added advantage over other solid state forms such as films since the pump power required to excite the molecules in the core of the fiber is less thereby utilising the pump power effectively. In 1987, Muto et.al investigated a dye doped step index polymer fiber laser. Afterwards, numerous researches have been carried out in this area demonstrating laser emission from step index, graded index and hollow optical fibers incorporating various dyes. Among various dyes, Rhodamine6G is the most widely and commonly used laser dye for the last four decades. Rhodamine6G has many desirable optical properties which make it preferable over other organic dyes such as Coumarin, Nile Blue, Curcumin etc. The research focus on the implementation of efficient fiber lasers and amplifiers for short fiber distances. Developing efficient plastic lasers with electrical pumping can be a new proposal in this field which demands lowest possible threshold pump energy of the gain medium in the cavity as an important parameter. One way of improving the efficiency of the lasers, through low threshold pump energy, is by modifying the gain of the amplifiers in the resonator/cavity. Success in the field of Radiative Decay Engineering can pave way to this problem. Laser gain media consisting of dye-nanoparticle composites can improve the efficiency by lowering the lasing threshold and enhancing the photostability. The electric field confined near the surface of metal nanoparticles due to Localized Surface Plasmon Resonance can be very effective for the excitation of active centers to impart high optical gain for lasing. Since the Surface Plasmon Resonance of nanoparticles of gold and silver lies in the visible range, it can affect the spectral emission characteristics of organic dyes such as Rhodamine6G through plasmon field generated by the particles. The change in emission of the dye placed near metal nanoparticles depend on plasmon field strength which in turn depends on the type of metal, size of nanoparticle, surface modification of the particle and the wavelength of incident light. Progress in fabrication of different types of nanostructures lead to the advent of nanospheres, nanoalloys, core-shell and nanowires to name a few. The thesis deals with the fabrication and characterisation of polymer optical fibers with various metallic and bimetallic nanostructures incorporated in the gain media for efficient fiber lasers with low threshold and improved photostability.