Suma, C.S; Dr. Manoj, N.(Cochin University of Science and Technology, June 14, 2016)
[+]
[-]
Abstract:
The thesis entitled “Photovoltaic and nonlinear optical studies of a few Donor-π-Acceptor molecules with s-triazine core” embodies the results of the investigations carried out to study unsymmetrically substituted s-Triazine cored starburst donor – acceptor systems with a bipodal acceptor/anchoring group design. The thesis opens with a review on the application of organic donor-acceptor systems in photovoltaics with special emphasis on applications in dye sensitised solar cells. The review also briefly discusses the application of such systems in the development of nonlinear optical materials.The unique structure of s-triazine do not permit direct coupling between the donor and acceptor moieties and this has been used as an effective tool for tuning HOMO and LUMO energy levels of such donor acceptor molecules. The effect of nature of the -bridge and the acceptor groups on the photovoltaic properties was studied and the results are presented in chapters 2, 3 and 4. Among the three types of -bridges studied, thiophene served as the best in terms of improving absorption spectral properties. Thiophene bridged dyes (DTT-CYA, DTT-RHA, DTT-BA and DTT-TBA) showed better coverage of the solar spectrum. Photovoltaic properties of these dyes were studied by constructing sandwhich model dye sensitized solar cells with nanocryasalline thin film of TiO2 on FTO coated with the respective dye as the photoanode, I-/I3- and Br-/Br3- as the redox couple/electrolyte and a platinized FTO as the cathode. The cell parameters and the photoconversion efficiency calculated show that the thiophene bridged dyes when used with Br-/Br3- as the redox couple/electrolyte have the optimal performance
Narayana Pillai, V; Dr.Murthy, A V S(Cochin University of Science And Technology, 1982)
[+]
[-]
Abstract:
The present study is aimed at observing the variations, in
space and time, of see of the important hydrographic parameters such
as sea water temperature, salinity and Resolved oxygen within the
coastal waters along the south-west coast of Indiametween Ratnagiri
(17°OO*N,73°20'E) and cape comorin ( 8°10'N,77°30*E). Specific data
relating to the process of upwelling and sinking was collected mainly
to evaluate the extent and intensity of the vertical mixing processes
active in the area under study. The study also attempted possible correlations between the observed parameters and the occurrence and migrations of some of the major pelagic fishery resources such as sardine,mackerel and anchovy in the area under study
Description:
School of marine sciences, Cochin University of Science And Technology
Reshmi, R; Dr.Sugunan, S(Cochin University of Science and Technology, September , 2009)
[+]
[-]
Abstract:
Biotechnology is currently considered as a useful altemative to conventional process technology in industrial and catalytic fields. The increasing awareness of the need to create green and sustainable production processes in all fields of chemistry has stimulated materials scientists to search for innovative catalysts supports. lmmobilization of enzymes in inorganic matrices is very useful in practical applications due to the preserved stability and catalytic activity of the immobilized enzymes under extreme conditions. Nanostructured inorganic, organic or hybrid organic-inorganic nanocomposites present paramount advantages to facilitate integration and miniaturization of the devices (nanotechnologies), thus affording a direct connection between the inorganic, organic and biological worlds. These properties, combined with good chemical stability, make them competent candidates for designed biocatalysts, protein-separation devices, drug delivery systems, and biosensors Aluininosilicate clays and layered double hydroxides, displaying, respectively, cation and anion exchange properties, were found to be attractive materials for immobilization because of their hydrophilic, swelling and porosity properties, as well as their mechanical and thermal stability.The aim of this study is the replacement of inorganic catalysts by immobilized lipases to obtain purer and healthier products.Mesocellular silica foams were synthesized by oil-in-water microemulsion templating route and were functionalized with silane and glutaraldehyde. " The experimental results from IR spectroscopy and elemental analysis demonstrated the presence of immobilized lipase and also functionalisation with silane and glutaraldehyde on the supports.The present work is a comprehensive study on enzymatic synthesis of butyl isobutyrate through esterification reaction using lipase immobilized onto mesocellular siliceous foams and montmorillonite K-10 via adsorption and covalent binding. Moreover, the irnrnobil-ization does not modify the nature of the kinetic mechanism proposed which is of the Bi-Bi Ping—Pong type with inhibition by n-butanol. The immobilized biocatalyst can be commercially exploited for the synthesis of other short chain flavor esters.
Mesocellular silica foams (MCF) were synthesized by microemusion templating method via two different routes (hydrothermal and room temperature). and were functionalized with silane and glutaraldehyde. Candida rugosa lipase was adsorbed onto MCF silica and clay using heptane as the coupling medium for reactions in non-aqueous media. I From XRD results, a slight broadening and lowering of d spacing values after immobilization and modification was observed in the case of MCF 160 and MCF35 but there was no change in the d-spacing in the case of K-10 which showed that the enzymes are adsorbed only on the external surface. This was further confirmed from the nitrogen adsorption measurements
Description:
Department of Applied Chemistry, Cochin University of Science and Technology
Jeena,Augustine; Dr.Sarita,Bhat G(Cochin University of Science and Technology, July 19, 2012)
[+]
[-]
Abstract:
This thesis entitled Physicochemical and molecular characterization of bacteriophages ΦSP-1and ΦSP-3, specific for pathogenic Salmonella and evaluation of their potential as biocontrol agent . Salmonella were screened using standard methodologies from various environmental samples including chicken caecum. Salmonella strains, which were previously isolated and stocked in the lab, were also included in this study as host, for screening Salmonella specific lytic phages. The Salmonella strain in this study designated as S49 which helped in phage propagation by acting as host bacteria was identified as Salmonella enterica subsp. enterica by 16S rRNA gene analysis and serotyping .
A total of three Salmonella specific phage named as ΦSP-1, ΦSP-2 and ΦSP-3 were isolated from chicken intestine samples via an enrichment protocol employing the double agar overlay method. ΦSP-1 and ΦSP-3 showing consistent lytic nature were selected for further study and were purified by repeated plating after picking of single isolated plaques from the lawns of Salmonella S49 plates. Both the phages produced small, clear plaques indicating their lytic nature. ΦSP-1 and ΦSP-3 were concentrated employing PEG-NaCl precipitation method before further characterization.
The focus of present study was to isolate, characterize and verify the efficacy of lytic bacteriophages against the robust pathogen Salmonella, capable of surviving under various hostile conditions. Two phages, ΦSP-1 and ΦSP-3, belonging to two families, Podovoridae and Siphoviridae were isolated.
Description:
Department of Biotechnology, Cochin University of Science and Technology
Ramya, R; Dr.Balasundaran, M; Dr.Jose, Kallarackal(Kerala Forest Research Institute, July , 2010)
[+]
[-]
Abstract:
S. album L. is the source of highly priced and fragrant heartwood which on steam
distillation yields on an average 57
per cent oil of high perfumery value. Global
demand for sandalwood is about 5000-6000
tons/year and that of oil is 100 tons/year.
Heartwood of sandal is estimated to fetch up to Rs. 3.7 million/ton and wood oil
Rs.70,000-100,000/
kg in the international market. Sandal heartwood prices have
increased from Rs. 365/ton in 1900 to Rs. 6.5 lakhs/ton in 1999-2000
and to Rs. 37
lakhs/ton in 2007. Substantial decline in sandalwood production has occurred from 3176
tons/year during 1960-‘
65 to 1500 tons/year in 1997-98,
and to 500 tons/year in 2007.Depletion of sandal resources is attributed to several factors, both natural and
anthropogenic. Low seed setting, poor seed germination, seedling mortality, lack of
haustorial connection with host plant roots, recurrent annual fires in natural sandal
forests, lopping of trees for fodder, excessive grazing, hacking, encroachments, seedling
diseases and spread of sandal spike disease are the major problems facing sandal. While
these factors hinder sandal regeneration in forest areas, the situation is accelerated by
human activities of chronic overexploitation
and illicit felling.Deterioration of natural sandal populations due to illicit felling, encroachments and
diseases has an adverse effect on genetic diversity of the species. The loss of genetic
diversity has aggravated during recent years due to extensive logging, changing landuse
patterns and poor natural regeneration. The consequent genetic erosion is of serious
concern affecting tree improvement programme in sandal. Conservation as well as mass
propagation are the two strategies to be given due importance. To initiate any
conservation programme, precise knowledge of the factors influencing regeneration and
survival of the species is essential. Hence, the present study was undertaken with the
objective of investigating the autotrophic and parasitic phase of sandal seedlings
growth, the effects of shade on morphology, chlorophyll concentration and chlorophyll
fluorescence of sandal seedlings, genetic diversity in sandal seed stands using ISSR
markers, and the diversity of fungal isolates causing sandal seedling wilt using RAPD
markers. All these factors directly influence regeneration and survival of sandal
seedlings in natural forests and plantations.
Latha,Thampuran; Dr.Damodaran,R(Cochin University of Science and Technology, August 25, 1986)
[+]
[-]
Abstract:
In India industrial pollution has become a subject of increasing concern.Incidents of industrial pollution have been reported from many parts of the country. Cochin, the collection site of the present study, being the industrial capital of Kerela is also a harbour, is vulnerable to pollution by trace metal contaminants. In the recent times, pollutants of greatest concern in the aquatic environment are those which are persistent such as toxic heavy metals and the chlorinated hydrocarbons which include insecticides and pesticides.The animals collected from the clam bed situated on the northern side af Cochin bermouth are subject to wide fluctuations in salinity both seasonal and tidal. also; salinity is considered as an important parameter influencing the.-physiological functioning of an organism. Hence, the salinity tolerance of the animal is worked out. Considering the potential vulnerability of Cochin backwaters to heavy metal pollution, the impact of heavy metal copper (II) on the bivalve Sunetta sripta was conceived. Static bioassays were conducted for the determination of the sublethal concentrations of the metal as a preliminary step towards the toxicity studies. Oxygen consumption and filtration rate which are considered as reliable sublethal toxicity indices were employed for investigating the toxic effects of the metal. Bioaccumulation, a physiological phenomenon which can be of importance from the public health point of view, and also in the assessment of environmental quality is also dealt with.
Description:
School of Marine Science, Cochin University of Science & Technology
Krishnakumar,P K; Dr.Damodaran,R(Cochin University Of Science And Technology, November 5, 1987)
[+]
[-]
Abstract:
No serious attempt has so far been made in India to make use
of the ‘Mussel watch’ concept as a useful tool for pollution monitoring
of the marine and estuarine environment. The recently conducted
'National seminar on mussel watch’ by the Cochin University of Science
and Technology (13-14 Feb, 1986) discussed the technical aspects related
to mussel watch programme and the application of sentinel organism
concept to the coastal areas of India.
It is well known that the biological and physiological
characteristics of the organism inhabiting tropical waters such as those
prevailing in India, and the ecological as well as the environmental
characteristics of temperate areas, where mussel watch programmes are
already in existence differ greatly. So it is essential to adopt the
techniques and standards developed for temperate species to the
situations and conditions in India. In this context it is a prerequisite
to collect information on physiology and other biological indices of
stress of possible sentinel organisms like P.viridis.
In consideration of the above, P. viridis which is a potential
sentinel organism, is selected for the present study
Description:
School Of Marine Sciences
Cochin University Of Science And Technology
Valsalakumari, C S; Dr.Samuel, C T(Cochin University of Science And Technology, 1990)
[+]
[-]
Abstract:
The vast areas of derelict swamps covered by macrophyton and swarmed
by insects scattered in different parts of India are at present either under
total negligence or utilized as waste disposal dumps. Eventhough Indian subcontinent
is ranked among the first ten fish producing countries in the world,
the fish production is not at par with the increasing need of protein in the
average Indian diet. So the water areas which become unusable for conventional
human activities like the swamps could be used for fish culture which would
increase the availability of protein in the form of fish flesh, thus providing
new opportunities to the fishermen. But the conversion of swamps for fish
culture would entail considerable expenditure. Hence the significance of a
group of fresh water fishes which have made their favourable abode the muddy
swamps of tropics depending partly on accessory _respiration to survive in the
inimical environment. The homeostasis achieved in such a hostile, hypoxic
medium make them excellent choices for culture in the derelict freshwater
bodies of India.
These air breathing fishes form an economically important group which
are highly esteemed as food fishes in many parts of South Asia and Africa.
Though their natural habitat seems to be the marshes, they have also conquered
other freshwater bodies like ponds, tanks, rivers and flooded paddy fields.
They can also tolerate slightly brackish waters. They are known for their nutritive,
invigorating and therapeutic qualities and are recommended by physicians
as diet during convalescence (Jhingran, 1982)
Description:
Department of Industrial Fisheries, Cochin University of Science and Technology
Smitha, Mohanlal; Dr. Jayalekshmy, A(National Institute for Interdisciplinary Science and Technology (CSIR), December , 2011)
[+]
[-]
Abstract:
The study was planned to investigate the bioactive compounds in Njavara
compared to staple varieties and their bioactivity to substantiate the medicinal
properties. Results of the study on chemical indices, antioxidant activity and antiinflammatory
activity (in vivo) of Njavara black rice bran and rice in comparison with
non-medicinal varieties like Sujatha and Palakkadan Matta rice bran and rice are given. The phytochemical investigation and quantification of Njavara extracts in
comparison with staple varieties are detailed in this study. The last chapter is divided in three sections (A, B and C). Section A comprises the antioxidant activity
by in vitro assays like DPPH, superoxide anion radical and hydrogen peroxide
scavenging activity of the compounds. Also, theoretical studies using DFT were carried
out based on DPPH radical scavenging activity for understanding the radical stability
and mechanism of antioxidant activity. Section B comprises the anti-inflammatory
activity of the identified compounds namely tricin and two flavonolignans in both in
vivo and in vitro models. Section C describes the cytotoxicity of the rare flavonolignans,
tricin 4’-O-(erythro-β-guaiacylglyceryl) ether and tricin 4’-O-(threo-β-guaiacylglyceryl)
ether towards multiple cancer cells belonging to colon, ovarian and breast tumours.