Nampoori, V P N; Senoy, Thomas; Jinesh, Mathew; Radhakrishnan, P; George, A K; Al-Harthi,R V; Ramanujan, R V; Anantharaman, M R(Sensors and Actuators: A Physical, May 11, 2010)
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Abstract:
Metallic glass alloy Metglas 2826 MB based amorphous magnetic thin films were
fabricated by the thermal evaporation technique. Transmission electron micrographs and
electron diffraction pattern showed the amorphous nature of the films. Composition of
the films was analyzed employing x-ray photoelectron spectroscopy and energy
dispersive x-ray spectroscopy techniques. The film was integrated to a long period fibre
grating. It was observed that the resonance wavelength of the fibre grating decreased with
an increase in the magnetic field. Change in the resonance wavelength was minimal at
higher magnetic fields. Field dependent magnetostriction values revealed the potential
application of these films in magnetostrictive sensor devices
Senoy, Thomas; Jinesh, Mathew; Radhakrishnan, P; Nampoori, V P N; George, A K; Al-Harthi, S H; Ramanujan, R V; Anantharaman, M R(Elsevier, 2010)
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Abstract:
Metallic glass alloy Metglas 2826 MB based amorphous magnetic thin films were fabricated by the thermal evaporation technique. Transmission electron micrographs and electron diffraction pattern showed the amorphous nature of the films. Composition of the films was analyzed employing X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy techniques. The film was integrated to a long period fibre grating. It was observed that the resonance wavelength of the fibre grating decreased with an increase in the magnetic field. Change in the resonance wavelength was minimal at higher magnetic fields. Field dependent magnetostriction values revealed the potential application of these films in magnetostrictive sensor devices.
Sudha Kartha, C(Taylor and francis, October 20, 2003)
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Abstract:
Polymer materials find application in optical storage technology,
namely in the development of high information density and fast access type
memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol
(PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized
and its comparison with methylene blue sensitized PVA in methanol and
complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented.
The optical absorption spectra of the thin films of these polymers
showed a strong and broad absorption region at 670-650 nm, matching the
wavelength of the laser used. A very slow recovery of the dye on irradiation was
observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pHof 3.8
and a sensitizer concentration of 4.67 10 5 g/ml were used. A diffraction
efficiency of up to 20% was observed for the MBPVA/alcohol system and an
energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films
with a spatial frequency of 588 lines/mm.
Sreekumar, K(Taylor and francis, October 20, 2003)
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Abstract:
Polymer materials find application in optical storage technology,
namely in the development of high information density and fast access type
memories. A new polymer blend of methylene blue sensitized polyvinyl alcohol
(PVA) and polyacrylic acid (PAA) in methanol is prepared and characterized
and its comparison with methylene blue sensitized PVA in methanol and
complexed methylene blue sensitized polyvinyl chloride (CMBPVC) is presented.
The optical absorption spectra of the thin films of these polymers
showed a strong and broad absorption region at 670-650 nm, matching the
wavelength of the laser used. A very slow recovery of the dye on irradiation was
observed when a 7:3 blend of polyvinyl alcohol/polyacrylic acid at a pHof 3.8
and a sensitizer concentration of 4.67 10 5 g/ml were used. A diffraction
efficiency of up to 20% was observed for the MBPVA/alcohol system and an
energetic sensitivity of 2000 mJ/cm2 was obtained in the photosensitive films
with a spatial frequency of 588 lines/mm.
Thomas Lee, S; Aneeshkumar, B; Radhakrishnan, P; Vallabhan, C P G; Nampoori, V P N(Elsevier, May , 2002)
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Abstract:
Optical fiber sensors developed for measuring pH values usually employ an unclad and unstrained section of the fiber. In this paper, we describe the design and fabrication of a microbent fiber optic sensor that can be used for pH sensing. In order to obtain the desired performance, a permanently microbent portion of a plastic optic fiber is coated with a thin film of dye impregnated sol–gel material. The measurements are simultaneously carried out in two independent detection schemes viz., the bright field detection configuration for detecting the core modes and dark field detection configuration, for detecting the cladding modes. The results of measurements of core mode-power and cladding mode-power variation with change in pH of a solution surrounding the coated portion of the fiber is presented. This paper thus demonstrates how a bare plastic fiber can be modified for pH sensing in a simple and cost effective manner.
Thomas Lee, S; Nampoori, V P N; Vallabhan, C P G; Radhakrishnan, P; Geetha, K(Society of Photo-Optical Instrumentation Engineers, 2002)
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Abstract:
Microbent optical fibers are potential candidates for evanescent wave sensing. We investigate the behavior of a permanently microbent fiber optic sensor when it is immersed in an absorbing medium. Two distinct detection schemes, namely, bright-field and dark-field detection configuration, are employed for the measurements. The optical power propagating through the sensor is found to vary in a logarithmic fashion with the concentration of the absorbing species in the surrounding medium. We observe that the sensitivity of the setup is dependent on the bending amplitude and length of the microbend region for the bright-field detection scheme, while it is relatively independent of both for the dark-field detection configuration. This feature can be exploited in compact sensor designs where reduction of the sensing region length is possible without sacrificing sensitivity.
Hatha, A A M; Edward, Gakpe; Pattanathu Rahman, K.S.M.(Journal of marine and atmospheric research, July , 2007)
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Abstract:
Biosurfactants are surface active compounds released by microorganisms. They are biodegradable non-toxic and
eco-friendly materials. In this review we have updated the information about different microbial surfactants. The
biosurfactant production depends on the fermentation conditions, environmental factors and nutrient availability. The
extraction of the biosurfactants from the cell-free supernatant using the solvent extraction procedure and the qualitative
and quantitative analysis has been discussed with appropriate equipment details. The application of the biosurfactant
includes biomedical, cosmetic and bioremediation. The type of microbial biosurfactants include trehalose lipids,
rhamnolipids, sophorolipids, glycolipids, cellobiose lipids, polyol lipids, diglycosyl diglycerides, lipoloysaccharides,
arthrofactin, lichensyn A and B, surfactin, viscosin, phospholipids, sulphonyl lipids and fatty acids. Rhamnolipid
biosurfactants produced by Pseudomonas aeruginosa DS10-129 showed significant applications in the bioremediation of
hydrocarbons in gasoline spilled soil and petroleum oily sludge. Rhamnolipid biosurfactant enhanced the bioremediation
process by releasing the weathered oil from the soil matrices and enhanced the bioavailability of hydrocarbons for microbial
degradation. It is having potential applications in the remediation of hydrocarbon contaminated sites. Biosurfactants from
marine microorganisms also offer great potential in bioremediation of oil contaminated oceanic environments
Krishna, C; Dr.Chandrasekaran,M(Cochin University of Science and Technology, August , 1995)
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Abstract:
A critical survey of the fruits and vegetable
markets of the towns and cities in South India reveals that
banana fruit stalk wastes share a dominant proportion among
the solid wastes generated. In the light of the review of
literature presented in the foregoing section, few reports are
available on the utilisation of banana waste for the
production of alcoholic beverages, biogas, and single cell
protein. However, it is not yet tried for the production of
industrial enzymes. Moreover, preliminary fermentation
studies conducted under uncontrolled conditions revealed that
banana fruit stalk could be aptly utilised as solid substrate?
for the industrial production of microbial amylases and
cellulases at a cheaper cost. Therefore, it was proposed to conduct a detailed study towards the development of a suitable fermentation process for the production of industrial enzymes using banana fruit stalk wastes, which is rich in carbohydrate, as solid substrate, employing bacteria, under SSF.
Description:
Department of Biotechnology, Cochin University of
Science & Technology,
Krishnamurthy,V; Dr.Samuel, C T(Cochin University of Science and Technology, July , 1985)
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Abstract:
The thesis deals with the bacterial flora of the Cochin backwaters. Sediment and the prawns
caught from these backwaters in quantitative and qualitative terms, their growth in relation to temperature, their susceptibility to various antibiotics, their role in terms of food for juvenile prawns and the presence of bacteria of public health significance. According to the researcher such a comprehensive study would be of some relevance to shell-fish processing industries apart from its academic value. The effect of antibiotics on the bacteria and the utility of bacteria as food for the juvenile prawns are studied and presented in different chapters.
Description:
School of Marine Science, Department of Industrial fisheries, Cochin University of Science and Technology
Rathna Kala, R; Dr.Chandrika, V(Cochin University of Science and Technology, 2000)
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Abstract:
The present study on "Microbial production of antibiotics from mangrove ecosystem” was carried out for a period of one year in four selected Stations, Mangalavana, Narakkal, Puthuvyppu and light house area of Puthuvyppu (9°55' — 10°10'N and 76°10‘ - 76°20'E) from January to December 1991. Though much emphasis has been given to occurrence and distribution of actinomycetes, an attempt was also made to understand the distribution patterns of other micro flora in the sediments. Data on physico-chemical parameters were also collected to find out their relationship if any with the microflora. The principle interest of the present investigation is to determineseasonal variations of antagonistic actinomycetes in selected mangrove ecosystem. The microbial interrelationship in mangrove sediments was found out by constructing the ratio between bacteria and actinomycetes, bacteria and fungi, fungi and actinomycetes. In addition temperature, pH, salinity, dissolved oxygen and organic carbon were determined seasonally and their possible relationship was statistically analyzed and the results are presented. Isolated actinomycetes were subjected to cross streak assay to know their nature of antibiotic activity against test fish pathogens and crude antibiotics were extracted from selected isolates and their inhibitory activity is studied and the results are discussed.
Hatha, A A M; Maqbool, T K; Suresh Kumar,S(Elsevier, June 26, 2002)
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Abstract:
Bacteriological quality of individually quick frozen (IQF) shrimp products produced from aquacultured tiger shrimp
(Penaeus monodon) has been analysed in terms of aerobic plate count (APC), coliforms, Escherichia coli, coagulase-positive
staphylococci, Salmonella, and Listeria monocytogenes. Eight hundred forty-six samples of raw, peeled, and deveined tail-on
(RPTO), 928 samples of cooked, peeled, and deveined tail-on (CPTO), 295 samples of headless, undeveined shell-on (HLSO),
and 141 samples of raw, peeled, and deveined tail-off (RPND) shrimps were analysed for the above bacteriological parameters.
Salmonella was isolated in only one sample of raw, peeled tail-on. Serotyping of the strain revealed that it was S. typhimurium.
While none of the cooked, peeled tail-on shrimp samples exceeded the aerobic plate count (APC) of 105 colony forming units
per gram (cfu/g), 2.5% of raw, peeled, tail-on, 6.4% of raw, peeled tail-off, and 7.5% of headless shell-on shrimp samples
exceeded that level. Coliforms were detected in all the products, though at a low level. Prevalence of coliforms was higher in
headless shell-on (26%) shrimps followed by raw, peeled, and deveined tail-off (19%), raw, peeled tail-on (10%), and cooked,
peeled tail-on (3.8%) shrimps. While none of the cooked, peeled tail-on shrimp samples were positive for coagulase-positive
staphylococci and E. coli, 0.6–1.3% of the raw, peeled tail-on were positive for staphylococci and E. coli, respectively.
Prevalence of staphylococci was highest in raw, peeled tail-off (5%) shrimps and the highest prevalence of E. coli (4.8%) was
noticed in headless shell-on shrimps. L. monocytogenes was not detected in any of the cooked, peeled tail-on shrimps. Overall
results revealed that the plant under investigation had exerted good process control in order to maintain superior bacteriological
quality of their products
Description:
International Journal of Food Microbiology 82 (2003) 213– 221
Jayachandran, K; Dr.Chandrasekaran,M(Cochin University of Science And Technology, August 28, 1998)
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Abstract:
Many of the existing methods for the treatment of rubber latex centrifugation
eflluent are not only unsatisfactory in their efliciency to effect near perfect treatment in
bringing down the COD to optimum level, but also time consuming and need a large
landspace. As the rate of effluent generation is extremely high (20 litres for kilogram of
rubber) there is a need for development of efficient system,capable of rapid reduction of
COD and BOD.
Though the organic load of the rubber efiluent is very high, it does not contain
much processed chemicals and therefore it can be considered as a ‘biological eflluent’.
Further, the ratio of the Chemical Oxygen Demand to Biological Oxygen Demand
(COD/BOD) of this effluent remain almost as a constant value. According to
Montgomery (1967), estimation of BOD is not ideally suited for studies on process
design, treatability, control of treatment plants, setting standards for treated effluents and
assessing the effect of polluting discharges on the oxygen resources of receiving waters.
Hence in the present study COD was measured to determine the impact of treatment
system on the effluent.
In the present study, attempts were made to evaluate the efficiencies of certain
methods such as packed bed reactor using immobilized microbial cells, rotating biological
contactor (RBC) and activated sludge process, for rapid and efficient treatment of
natural rubber latex centrifugation effluent. In addition, studies were also carn'ed out to develop a suitable bioprocess for the coagulation of skim latex, as an alternative to the
presently used acid coagulation process towards reducing the pollution load, besides
recovering quality rubber
Description:
Department of Biotechnology, Cochin
University of Science and Technology