Anantharaman, M R; Muhammad, Abdul Jamal E; Mohanan, P; Joy, P A; Philip, Kurian(Springer, May 29, 2009)
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Abstract:
Nickel–rubber nanocomposites were synthesized
by incorporating ferromagnetic nickel nanoparticles in a
natural rubber as well as neoprene rubber matrix. Complex
dielectric permittivity and magnetic permeability of
these composites were evaluated in the X-band microwave
frequencies at room temperature using cavity perturbation
technique. The dielectric loss in natural rubber is smaller
compared to neoprene rubber. A steady increase in the dielectric
permittivity is observed with increase in the content
of nickel in both the composites. The magnetic permeability
exhibits a steady decrease with increase in frequency and
magnetic loss shows a relaxation at 8 GHz. The suitability of
these composites as microwave absorbers is modeled based on the reflection loss which is dependant on the real and
imaginary components of the complex dielectric permittivity
and magnetic permeability.
One-pot acetalizations of cyclohexanone. acetophenone and benzophenone were carried out using methanol over H-montmorillonite clay
(a mesoporous material). silica, alumina, and different zeolites such as HFAU-Y.HBeta, H-ZSM-5, and H-mordenite. In all the cases a single
product-the corresponding dimethylacetal-was obtained in high yields. Hemiacetal formation was not observed with any catalyst. A
comparison of catalytic activity indicated that montmorillonite K-10 is the most active catalyst for the reaction. As evidenced by the reaction
time studies, the catalyst decay is greater over the zeolite catalyst than over the clay.
Anantharaman, M R; Vaidyanathan, G; Arulmurugan, R; Likhite, S D; Milind, Vaidya; Sendhilnathan, S; Senthilram, N D(NATL INST SCIENCE COMMUNICATION, December 12, 2003)
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Abstract:
Mixed ferrites belonging to the type Mn0.9Zn0.1Fe2O4 have been prepared by the double sintering method and by the
chemical co-precipitation for comparing their magnetic properties. Sintered and precipitated ferrites exhibit different
characteristics, especially in their magnetic properties like magnetization (Ms), coercive field (Hc) and Curie temperature
(Tc). The sintered particles were size reduced in order to compare with the nanosized co-precipitated particles. The effect of
grinding has also been studied. Particles have been collected at regular intervals of grinding and their properties have been
studied. The increase in the coercive field has been recorded by a hysteresis curve tracer confirming size reduction. X-ray
diffraction studies confirmed the structure and consequent size reduction
Description:
Indian Journal of Engineering & Materials Sciences
Vol. 11, August 2004, pp. 289-294
The effect of various processing parameters, such as nip gap, friction ratio
and roll temperature, on the tensile properties of short Kevlar aramid
fibre-thermoplastic polyurethane composite has been investigated and the tensile
and tear fracture surfaces have been characterised using a scanning electron microscope.
A nip gap of 0.45 mm, a friction ratio of 1.15 and a roll temperature of 62°C
was found to give optimum mechanical properties. Scanning electron microscopy
study revealed a higher extent of fibre orientation in the milling direction in the
above condition.
Paulose,C S; Dakshinamurti,K(Department of Biotechnology, December 19, 1984)
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Abstract:
The high-affinity bindings of [3H]-5-hydroxytryptamine to serotonin S-1 receptors,
[3H]-ketanserin to serotonin S-2 receptors in the cerebral cortex, [3H]-
fluphenazine to dopamine D-1 receptors, and [3H]-spiroperidol to dopamine D-2
receptors in the corpus striatum were studied in pyridoxine-deficient rats and
compared to pyridoxine-supplemented controls. There was a significant increase
in the maximal binding (Bmax) of serotonin S-1 and S-2 receptors with a significant
decrease in their binding affinities (Kd). However, there were no significant
changes either in the maximal binding or binding affinity of striatal dopamine D-
1 and D-2 receptors. Receptor sensitivity seems to correlate negatively with the
corresponding neurotransmitter concentrations in the pyridoxine-deficient rats.
Pyroja, S; Biju,M P; Paulose,C S(Department of Biotechnology, February 11, 1998)
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Abstract:
Effect of pyridoxine on growth, metabolism and cellular activity of
freshwater prawn Macrobrachiuni rosenbergii was studied. Postlarvae
(PL-10) of M. rosenbergii were fed with clam meat containing
various concentrations of pyridoxine. After 30 days RNA and DNA
of the abdominal tissues were estimated. Length, weight and RNA
to DNA ratio increased significantly with increasing concentrations
of pyridoxine. The effect of pyridoxine on the metabolic enzyme,
malate dehydrogenase, was also studied. Vmax showed a significant
decrease and the (Km) showed a significant increase in experimental
groups compared to control.
Jose, Joseph; Dr.Gopakumar, K(Cochin University Of Science And Technology, August 21, 1989)
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Abstract:
Frozen storage characteristics and shelflife vary
considerably among species as well as within the species
(Powrie, 1973; Fennema. 1973). This can be attributed to the
variation in the composition of fish among various species.
In certain species like sardines and mackerel. wide seasonal
variation in chemical composition occur within the species.
These variations affect the quality and shelflife. The
nutritional level of water. spawning, method of catching,
struggling etc. are found to have profound influence on the
condition of the fresh fish.
Soon after death the deteriorative changes in fish start
due to autolysis and bacterial growth. The rate of these
changes depends mainly on temperature. The handling methods
have great influence on bacterial contamination. Thus the type
oi'handling. temperature control. period of chill storage.
processing methods. type of freezing, condition of frozen
storage and period of storage affect the quality and shelflife
Of the fisho
In the present study extensive investigations were
carried out on various factors affecting the quality of fish
as well as their effect on the physical. chemical and sensory
qualities of fish during frozen storage and the shelflife
Description:
Central Institute Of Fisheries Technology,Cochin University Of Science And Technology
Siby, Zacharias; Dr. James, Manalel(Cochin University of Science and Technology, June , 2011)
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Abstract:
The study was an attempt to find out the effect of Sales Promotion,Price and Premium Promotion,on Consumer Based Brand Equity.The dimensions of consumer Based Brand Equity under study were Brand Awareness and Associations,Perceived Quality and Brand Loyalty.The Product categories under study were Convenience Products,shopping Products and Specialty Products and the product classes taken were Toothpastes,Colour Television and Athletic Shoes.The brands under study were Convenience Products-Anchor,Closeup,Colgate and Dabur:Shopping products-LG,Onida,Samsung and Sony and Specialty Products-Action,Adidas,Nike and Reebok.The primary objective of the study was to examine the effect of Sales Promotion,Price and Premium Promotion,on Consumer Based Brand Equity(CBBE)
Description:
School of Management Studies,Cochin University of Science and Technology
Litty, Irimpan; Deepthy, A; Bindu, Krishnan; Kukreja, L M; Nampoori, V P N; Radhakrishnan, P(Elsevier, 2008)
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Abstract:
In the present work, we report the third order nonlinear optical properties of ZnO thin films deposited using self assembly, sol gel process as well as pulsed laser ablation by z scan technique. ZnO thin films clearly exhibit a negative nonlinear index of refraction at 532 nm and the observed nonlinear refraction is attributed to two photon absorption followed by free carrier absorption. Although the absolute nonlinear values for these films are comparable, there is a change in the sign of the absorptive nonlinearity of the films. The films developed by dip coating and pulsed laser ablation exhibit reverse saturable absorption whereas the self assembled film exhibits saturable absorption. These different nonlinear characteristics in the self assembled films can be mainly attributed to the saturation of linear absorption of the ZnO defect states.
Sreeraj, M; Sumam, Mary Idicula(IEEE, December 7, 2012)
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Abstract:
The span of writer identification extends to broad
domes like digital rights administration, forensic expert decisionmaking
systems, and document analysis systems and so on. As the
success rate of a writer identification scheme is highly dependent
on the features extracted from the documents, the phase of
feature extraction and therefore selection is highly significant for
writer identification schemes. In this paper, the writer
identification in Malayalam language is sought for by utilizing
feature extraction technique such as Scale Invariant Features
Transform (SIFT).The schemes are tested on a test bed of 280
writers and performance evaluated
Chloroprene rubber was blended with whole tire reclaimed rubber
(WTR) in presence of different levels of a coupling agent Si69 [bis-
(3-(triethoxysilyl)propy1)tetrasuIfide] and the cure characteristics and
mechanical properties were studied. The rate and state of cure were
also affected by the coupling agent. While the cure time was increased,
the cure rate and scorch time were decreased with increasing silane
content. Tensile strength, tear strength, and abrasion resistance were
improved in the presence of coupling agent. Compression set and
resilience were adversely affected in presence of silane-coupling agent.Aging studies showed that the blends containing the coupling agent
were inferior to the unmodified blends.
Blends of nitrile rubber and reclaimed rubber containing different levels of a
coupling agent, Si 69 (bis(3- triethoxysilyl propyl)(tetrasulphide) were prepared
and the cure characteristic's and mechanical properties were studied. Optimum
loading of Si-69 was found to be a function of blend ratio. 3 phi- of Si 69 in a
70:30. Blend was found to be the optimum combination with respect to the
mechanical properties. The rate and state of cure were also affected bv the
conp/ing agent. Tensile strength, tear strength and abrasion resistance were
improved in the presence of coupling agent. While the state of cure improved,
the cure rate and scorch time decreased with increasing silane content. Ageing
studies showed that the blends containing the coupling agent were inferior to
the unmodified blends.
Santhi, A; Umadevi, M; Ramakrishnan, V; Radhakrishnan, P; Nampoori, V P N(Elsevier, 2004)
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Abstract:
Nano structured noble metals have very important applications in diverse fields as photovoltaics, catalysis, electronic and magnetic devices, etc. Here, we report the application of dual beam thermal lens technique for the determination of the effect of silver sol on the absolute fluorescence quantum yield (FQY) of the laser dye rhodamine 6G. A 532 nm radiation from a diode pumped solid state laser was used as the excitation source. It has been observed that the presence of silver sol decreases the fluorescence quantum efficiency. This is expected to have a very important consequence in enhancing Raman scattering which is an important spectrochemical tool that provides information on molecular structures. We have also observed that the presence of silver sol can enhance the thermal lens signal which makes the detection of the signal easier at any concentration.
Kanakavalli,Susarla S; Dr.Balakrishnan, K P(Cochin University of Science and Technology, March 10, 1987)
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Abstract:
The extraction and use of metals has been the mainstay for the sustained development and progress of a nation. Metals, though fairly stable in the natural environment are found in trace quantities in water bodies. Attention has therefore been focused to identify the metals that impair the water quality. In the last few decades the concern about the fate of these metals in the aquatic system has been gaining momentum, particularly in the industrial belts. The disasters caused by metal poisoning in recent times have prompted an indepth study of the interaction of metals with aquatic biota. Kerala, basically an agriculture oriented state has witnessed the upsurgence of various industries as a part of the nationwide economic development programme. Cochin has been identified as the industrial capital of the state.The present study is an attempt towards a better understanding of the metal-phytoplankton interactions with special reference to the physiological changes in the species. various parameters such as temperature, salinity, pH, nutrients, number of cells, photosynthetic pigments, carbohydrates, protein and lipid are studied to highlight the complexity of metal..phytoplankton interaction
Description:
School of Environmental Studies,
Cochin University of Science and Technology
Dhanya,P R; Dr.Saleena, Mathew(Cochin University of Science And Technology, October 16, 2012)
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Abstract:
Unprocessed seafood harbor high number of bacteria, hence are more prone to
spoilage. In this circumstance, the use of spice in fish for reduction of microorganism can
play an important role in seafood processing. Many essential oils from herbs and spices are
used widely in the food, health and personal care industries and are classified as GRAS
(Generally regarded as safe) substances or are permitted food additives. A large number of
these compounds have been the subject of extensive toxicological scrutiny. However, their
principal function is to impart desirable flavours and aromas and not necessarily to act as
antimicrobial agents. Given the high flavour and aroma impact to plant essential oils, the
future for using these compound as food preservatives lies in the careful selection and
evaluation of their efficacy at low concentrations but in combination with other chemical
preservatives or preservation processes. For this reason they are worth of study alone or in
combination with processing methods in order to establish if they could extend the shelf-life
of foods.
In this study, the effect of the spices, clove, turmeric, cardamom, oregano, rosemary
and garlic in controlling the spoilage and pathogenic bacteria is investigated. Their effect on
biogenic amine formation in tuna especially, histamine, as a result of bacterial control is also
studied in detail. The contribution of spice oleoresin in the sensory and textural parameters
is investigated using textural profile analysis and sensory panel. Finally, the potential of
spices in quality stabilization and in increasing the shelf–life of tuna during frozen storage is
analysed
Description:
School of Industrial Fisheries
Cochin University of Science and Technology
Jayaraj, M K(Electrochemical Society, July 18, 2007)
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Abstract:
ZnGa2O4:Dy3+ phosphor thin films were deposited on quartz substrates by radio frequency rf magnetron sputtering and the effect
of substrate temperature on its structural and luminescent properties was investigated. Polycrystalline film could be deposited even
at room temperature. The crystalline behavior, Zn/Ga ratio, and surface morphology of the films were found to be highly sensitive
to substrate temperature. Under UV illumination, the as-deposited films at and above 300°C gave white luminescence even
without any postdeposition treatments. The photoluminescent PL emission can be attributed to the combined effect of multicolor
emissions from the single luminescence center Dy3+ via host-sensitization. Maximum PL emission intensity was observed for the
film deposited at 600°C, and the CIE chromaticity coordinates of the emission were determined to be x,y = 0.34, 0.31 .
Sajan, D George; Augustine, S; Mathai, E; Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(WILEY-VCH Verlag GmbH&Co, 2003)
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Abstract:
An open cell configuration has been employed for the photoacoustic measurement of the thermal diffusivity of undoped Bi2Se3 crystals and Bi2Se3 crystals doped with various concentrations of Te. The amplitude of the photoacoustic signal obtained under heat transmission configuration as a function of chopping frequency is used to evaluate the numerical value of thermal diffusivity, α. Doped samples show a substantial reduction in the value of α compared to undoped samples. The variations in the thermal diffusivity of the doped samples are explained in terms of the phonon assisted heat transfer mechanism. It is seen that α is very sensitive to structural variations arising from doping. The experimentally observed results are correlated with X-ray diffraction studies.