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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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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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.
Maya, I; Dr.Sankaranarayanan, K C(Cochin University of Science and Technology, 2002)
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Abstract:
The present study was an attempt to analytically approach the problem of farm
poverty in Kerala from an entirely different angle by incorporating an independently
developed and reformulated definition of poverty line in terms of physical units of
operational holdings (say, acre). The entire discussion on farm poverty emerged out of
proper co-ordination of two important factors popularly considered as the distinct
features of I<erala's agrarian sector, viz, unparalleled proliferation of marginal holdings
and the unique and emirable position enjoyed by the state in terms of farm
productivity. This brief analytical study on farm poverty, conducted in the light of inter
regional variations in farm productivity tried to highlight various grave issues deserving
thorough introspection.
Description:
Department of Applied Economics,Cochin University of Science and Technology
Jomi, Thomas; Dr. Anil Kumar, S(Cochin University of Science and Technology, September , 2010)
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Abstract:
Farm communication and extension programs are vital part of the farm
development attempts. Electronic media plays a major role in farm extension
activities. Kerala, the consumer state, which was a complete agricultural state
in pre-independence period, is the sprouting land of agricultural extension and
publication activities in print media. Later AIR (All India Radio) farm programs
and farm broadcasting of Doordarshan enriched the role of electronic media in
farm extension activities. The media saturated southern state of India received
this new electronic media farm communication revolution whole heartedly.
However, after 1990, Kerala witnessed a flood of private T V channels and
currently there are 24 channels in this regional language, named Malayalam. All
major news and entertainment channels are broadcasting farm programs. Farm
programs of AIR and Doordarshan, broadcasted in Malayalam language, have
been well accepted to the farmers‘ in Kerala.
However, post-independence period, witnessed the formation of Kerala state in
Indian Union and the first ballot-elected communist Government started its
administration. After the land reform bills, the state witnessed a gradual
decrease in agricultural production. Even if it is not reflected much in the
attitude and practices of farm community and farm broadcast of traditional
electronic broadcasting, a change is observable after the post-liberalization era
of India. Private Television channels, which were focused on entertainment
value of programs, started broadcasting farm programs and the parameters of
program production went through certain changes.
In this situation, there is ample relevance for a study about the farm programs
of electronic media in terms of a comparative study of audience perception. The
study is limited in the state of Kerala as it is the most media saturated state in
India.
The study analyzes the rate, nature and scope of adoption of farming methods
transmitted through electronic media (T.V. and Radio) in Malayalam language.All kinds of Farm programs including comprehensive program serials, success
stories, seasonal cropping methods, experts opinion, been analyzed on the
basis of the following objectives.
To find whether propagating new farm methods through farm programs
in electronic media or the availability of adequate infrastructure and
economic factors make a farmer to adopt a new farming method.
To find which electronic media has more influence on farmers to adopt
agricultural programs.
To find which form of electronic media gets better feedback from farmers
To find out whether the programs of T.V. or Radio is more acceptable to
farmers than the print media.
To find whether farmers gets the message through their preferred
medium for the message.
The researcher recorded opinions from a panel of agricultural officers, farm
Information officers, agro extension researchers and experts. According to their
opinions and guidelines, a pilot study is designed and conducted in Kanjikuzhy
Panchayath, in Alappuzha district, Kerala. The Panchayath is selected by
considering its ideal nature of being the sample for a social Science research.
Besides, the nature of farming in the Panchayath, which devoid of the
cultivation of cash crops also supported its sample value.
As per the observations from the pilot study, researcher confirmed the
Triangulation method as the methodology of research. The questionnaire
survey, being the primary part contained 42 Questions with 6 independent and
32 dependent variables. The survey is conducted among 400 respondents in
Idukki, Alappuzha and Pathanamthitta districts considering geographical
differences and distribution of different types of crops. The response from a
total of 360 respondents, 120 from each district, finally selected for tabulation
and data analysis.The data analysis, based on percentage analysis, along with the results from
focus group discussion among a selected group of 20 farmers, together
produced the results as follows.
Farmers, who are the audience of farm programs, have a very serious
approach towards the medium. They are maintaining a critical point of view
towards the content of the programs. Farmers are reasonably aware about the
financial side of the programs and the monitory aspirations of both private and
Government owned Television channels.
Even though, the farmers are not aware on the technical terminology and
jargons, they have ideas about success stories, program serials and they are
even informed about channels are not maintaining an audience research
section like AIR.
Though the farmers accept Doordarshan as the credential source of farm
information and methods, they are inclined to the entertainment value of
programs too. They prefer to have more entertainment value for the programs
of Doordarshan. Surprisingly, they have very solid suggestions on even about
the shots which add entertainment value to the farm broadcasting methods of
Doordarshan.
Farmers are very much aware about the fact that media is just an instrument for
inspiration and persuasion. They strongly believe that the source of information
and new methods is agricultural research and an effective change happens
only when there are adequate infrastructure and marketing facilities, along with
the proper support from Government agricultural guideline and support systems
like Krishi Bhavans. They strongly believe that media alone cannot create any
magic in increasing agricultural production.
Farmers are pointing out the lack of response to the feedback and queries of
farmers on farming methods, as an evidence for the difference in levels of
commitment of Government and private owned Television channels.Farmers are still perceiving AIR farm programs are far more committed to
farmers and farming than any other electronic medium. However, they are
seriously lacking Radio receivers with medium wave reception facility.
Farmers perceive that the farming methods on new crops are more adoptable
than the farming methods of traditional crops in both private and Government
owned Television channels. There are multiple factors behind this observation
from farmers.
Farmers changed in terms of viewing habits and they prefer success stories,
which are totally irrelevant and they even think that such stories encourage
people to go for farming and they opined that such stories are good sources of
inspiration. However, they are all very much sure about the importance and
particular about the presence of entertainment factor even in farm programs.
Farmers expect direct interaction of any expert of the new farming method to
implement the method in their agriculture practices. Though introduction of a
new idea in the T.V. is acceptable, farmers need the direct instruction of expert
on field to start implementing the new farming practices
Farmers still have an affinity towards print media reports and agricultural pages
and they have complaints to print media on the removal of agricultural
information pages from news papers. They prefer the reports in print media as it
facilitates them to collect and refer articles when they need it.
Farmers are having an eye of doubt about the credibility of farm programs by
private T.V. channels. Even if they prefer private Television channels for
listening and adopting new farming methods and other farm information, they
scrutinize programs to know whether they are sponsored programs by agrochemical
or agro-fertilizer manufacturer.
Description:
Department of Applied Economics,Cochin University of Science and Technology
Manju, Mary Joseph; Dr.Chandramohanakumar, N(Cochin University of Science and Technology, October , 2009)
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Abstract:
The biogeochemistry of mangroves are the least understood ecological properties because of their sediment complexicity due to the tidal influx of allochthonous organic matter and the autochthonous inputs.In order to understand the relative importance of biogeochemical processes,it is necessary not only to characterise and qualify the organic matter but also to identify its major sources .The present study is a preliminary investigation to identify the sources of organic matter in three mangrove systems of Cochin Estuary using fatty acid biomarkers,δ13 C of total organic matter,elemental composition and biochemical composition.
Description:
Department of Chemical Oceanography,Cochin University of Science and
Technology