Benjamin Varghese, P; Dr.Madhusoodanan, K N(Cochin University Of Science And Technology, February 15, 2013)
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Abstract:
The objective of the preset work is to develop optical fiber
sensors for various physical and chemical parameters. As a part of this
we initially investigated trace analysis of silica, ammonia, iron and
phosphate in water. For this purpose the author has implemented a dual
wavelength probing scheme which has many advantages over
conventional evanescent wave sensors. Dual wavelength probing
makes the design more reliable and repeatable and this design makes
the sensor employable for concentration, chemical content,
adulteration level, monitoring and control in industries or any such
needy environments. Use of low cost components makes the system
cost effective and simple. The Dual wavelength probing scheme is
employed for the trace analysis of silica, iron, phosphate, and
ammonia in water. Such sensors can be employed for the steam and
water quality analysers in power plants. Few samples from a power
plant are collected and checked the performance of developed system
for practical applications.
Description:
Department of Instrumentation,
Cochin University of Science and Technology
Kishore,V C; Dr.Sudha Kartha,C; Dr. Sreekumar, K(Cochin University of Science & Technology, June , 2008)
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Abstract:
This Thesis discussed molecules suitable for photorefractive effect. Out
of the molecules studied, only one system was used to make photorefractive polymers system. Other molecules, especially, the electro-optic
polymer, Poly(3-methacrloyl-1-(4'-nitro-4-azo-1'-phenyl)phenylalanine-co-
methyl methacrylate) can be subjected to more detailed studies to explore
the possibilities of using them for electro-optic applications. Though not included in the thesis, the efficient photoconductor, Poly(6-tert-butyl-3-
phenyl-3,4-dihydro-2H-1,3-benzoxazine) sensitized with C60, which was described in Chapter 3 showed a low magnitude photovoltaic effect. This
hints at the possibility of using this system for organic solar cells also. The thesis presented the initial observation of photorefractive effect in
a polybenzoxazine based polymer system. A detailed analysis of the effect of C60, ECZ and DR1 can be carried out to check for the possibility of a high efficiency photorefractive system.
Description:
Applied Optics Division, Department of Physics, Cochin University of Science and Technology
Jaya, S; Dr. Ramakrishna, S V(Cochin University Of Science And Technology, August 19, 1999)
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Abstract:
P rosea syn. Indica belong to the family of plumbaginaceae, is an
important medicinal plant, cultivated widely in India. The roots of these
plant are generally used for medicinal purposes mainly as diuretic,
germicidal, vessicant, and abortifacient. It is also used for anaemia,
diarrhea, leprosy and common wart. The bark of the root contains orange
yellow pigment named plumbagin, a crystalline substance, belongs to the
class of naphthoquinone. Its chemical structure is 5-hydroxy 2-methyl 1,4naphthoquinone. Apart from P rosea, P zeylanica, P europea, Drosera
and Drosophyllum also contains plumbagin. The most exploited source of
plumbagin is, of course, P. rosea roots. The roots contain O.9mg/ g D.Wt. of
plumbagin in the roots. These plants grow very slowly and the roots suitable
for plumbagin extraction can be obtained only after several years of growth.
The productivity of the plant is also rather poor. The focus of the present study was to develop alternative strategies to obtain plumbagin. The tissue culture of P rosea for micropropagation has been studied
Description:
Department Of Biotechnology,Cochin University Of Science And Technology
Priya, Viswanath; Dr. Eby Thomas, Thachil(Cochin University of Science and Technology, September , 2007)
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Abstract:
Research in the field of polymer modified cement has been carried out for
the last 70 years or more. Polymers are mostly used to enhance durability and
sustainability of cement concrete and in combination with classical construction
materials a synergistic effect is obtained. In this work different polymers were
added to Portland cement in various proportions and the mechanical and
chemical resistance properties of the resultant composites when exposed to
chemical environments were studied. Microstructural studies were also carried
out to investigate the morphology of the composite and analyse the nature of
interactions taking place between the cement and polymer phases. Though most
polymers did not improve the compressive strength of the cement paste, it was
found that they enhanced the resistance of the virgin cement paste to external
chemical environments. The polymers seal the pores in the cement matrix and
bridge the microcracks within the composite. Some of the polymers underwent
chemical interactions with the cement paste thereby interfering in the hydration
of cement. Polymers also decreased the leachability of water soluble components
of virgin cement resulting in composites having improved durability. An attempt
to correlate the structure of the polymers with the properties of the resultant
composites is also presented.
Description:
Department of
Polymer Science and Rubber Technology, Cochin University of
Science and Technology
Sanal, K C; Dr.Jayaraj, M K(Cochin University of Science And Technology, January 27, 2014)
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Abstract:
Semiconductor physics has developed significantly in the field of re-
search and industry in the past few decades due to it’s numerous
practical applications. One of the relevant fields of current interest in
material science is the fundamental aspects and applications of semi-
conducting transparent thin films. Transparent conductors show the
properties of transparency and conductivity simultaneously. As far
as the band structure is concerned, the combination of the these two
properties in the same material is contradictory. Generally a trans-
parent material is an insulator having completely filled valence and
empty conduction bands. Metallic conductivity come out when the
Fermi level lies within a band with a large density of states to provide
high carrier concentration. Effective transparent conductors must nec-
essarily represent a compromise between a better transmission within the visible spectral range and a controlled but useful electrical con-
ductivity [1–6]. Generally oxides like In2O3, SnO2, ZnO, CdO etc,
show such a combination. These materials without any doping are
insulators with optical band gap of about 3 eV. To become a trans-
parent conductor, these materials must be degenerately doped to lift
the Fermi level up into the conduction band. Degenerate doping pro-
vides high mobility of extra carriers and low optical absorption. The
increase in conductivity involves an increase in either carrier concen-
tration or mobility. Increase in carrier concentration will enhance the
absorption in the visible region while increase in mobility has no re-
verse effect on optical properties. Therefore the focus of research for
new transparent conducting oxide (TCO) materials is on developing
materials with higher carrier mobilities.
Description:
Department of Physics
Cochin University of Science and Technology
Kamalakanth, C.K; Dr .Srinivasa Gopal, T.K(April 21, 2016)
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Abstract:
Fish and fishery products are having a unique place in global food
market due to its unique taste and flavour; moreover, the presence of easily
digestible proteins, lipids, vitamins and minerals make it a highly demanded
food commodity.Fishery products constitute a
major portion of international trade, which is a valuable source of foreign
exchange to many developing countries.Several new technologies are emerging to produce various value
added products from food; “extrusion technology” is one among them.
Food extruder is a better choice for producing a wide variety of high value
products at low volume because of its versatility. Extruded products are
shelf-stable at ambient temperature. Extrusion cooking is used in the
manufacture of food products such as ready-to-eat breakfast cereals,
expanded snacks, pasta, fat-bread, soup and drink bases. The raw materialin the form of powder at ambient temperature is fed into extruder at a known
feeding rate. The material first gets compacted and then softens and
gelatinizes and/or melts to form a plasticized material, which flows
downstream into extruder channel and the final quality of the end products
depends on the characteristics of starch in the cereals and protein ingredient
as affected by extrusion process. The advantages of extrusion process are
the process is thermodynamically most efficient, high temperature short
time enables destruction of bacteria and anti-nutritional factors, one step
cooking process thereby minimizing wastage and destruction of fat
hydrolyzing enzymes during extrusion process and enzymes associated with
rancidity.
Ancy, Sebastian; Dr.Ramachandran,A(Cochin University of Science & Technology, January , 2009)
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Abstract:
Shrimp Aquaculture has provided tremendous opportunity for the
economic and social upliftment of rural communities in the coastal areas of our
country Over a hundred thousand farmers, of whom about 90% belong to the
small and marginal category, are engaged in shrimp farming. Penaeus monodon is
the most predominant cultured species in India which is mainly exported to highly
sophisticated, quality and safety conscious world markets. Food safety has been of
concem to humankind since the dawn of history and the concern about food safety
resulted in the evolution of a cost effective, food safety assurance method, the
Hazard Analysis Critical Control Point (HACCP). Considering the major
contribution of cultured Penaeus monodon to the total shrimp production and the
economic losses encountered due to disease outbreak and also because traditional
methods of quality control and end point inspection cannot guarantee the safety of
our cultured seafood products, it is essential that science based preventive
approaches like HACCP and Pre requisite Programmes (PRP) be implemented in
our shrimp farming operations. PRP is considered as a support system which
provides a solid foundation for HACCP. The safety of postlarvae (PL) supplied
for brackish water shrimp farming has also become an issue of concern over the
past few years. The quality and safety of hatchery produced seeds have been
deteriorating and disease outbreaks have become very common in hatcheries. It is
in this context that the necessity for following strict quarantine measures with
standards and code of practices becomes significant. Though there were a lot of
hue and cry on the need for extending the focus of seafood safety assurance from
processing and exporting to the pre-harvest and hatchery rearing phases, an
experimental move in this direction has been rare or nil. An integrated
management system only can assure the effective control of the quality, hygiene
and safety related issues. This study therefore aims at designing a safety and
quality management system model for implementation in shrimp farming and
hatchery operations by linking the concepts of HACCP and PRP.
Description:
School Of Industrial
Fisheries, Cochin University of Science and Technology
Jayalakshmy, M S; Jacob, Philip(Cochin University Of Science And Technology, May , 2015)
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Abstract:
The present work emphasises on the synthesis and characterization of electro-active polymer-ceramic nanocomposites which can be used for pyroelectric thermal/infrared detection applications. Two sets of samples belong to polymer-microcrystalline composites have also been investigated in the work. The polymers used in the work have been commercially available ones, but the nanoceramics have been synthesized following simple chemical routes and aqueous organic gel routes. After characterizing the nanoceramics for their structure by powder XRD, they have been dispersed in liquid polymer and sonicated for uniform dispersion. The viscous mixture so formed was cast in the form of films for experimentation. Samples with volume fraction of the ceramic phase varied from 0 to 0.25 have been prepared. Solution growth was followed to prepare microcrystalline samples for the polymer-microcrystalline composites. The physical properties that determine the pyroelectric sensitivity of a material are dielectric constant, dielectric loss, pyroelectric coefficient, thermal conductivity and specific heat capacity. These parameters have been determined for all the samples and compositions reported in this work.The pyroelectric figures of merit for all the samples were determined. The pyroelectric figures of merit that determine the pyroelectric sensitivity of a material are current sensitivity, voltage responsivity and detectivity. All these have been determined for each set of samples and reported in the thesis. In order to assess the flexibility and mouldability of the composites we have measured the Shore hardness of each of the composites by indentation technique and compared with the pyroelectric figures of merit. Some important factors considered during the material fabrication stages were maximum flexibility and maximum figures of merit for pyroelectric thermal/IR detection applications. In order to achieve these goals, all the samples are synthesized as composites of polymers and nano/microcrystalline particles and are prepared in the form of freestanding films. The selected polymer matrices and particle inclusions possess good pyroelectric coefficients, low thermal and dielectric properties, so that good
pyroelectric figures of merit could be achieved. The salient features of the work include the particle size of the selected ceramic materials. Since they are in nanometer size it was possible to achieve high flexibility and moldability with high figures of merit for even low volume fractions of inclusions of the prepared nanocrystalline composites. In the case of microcrystalline TGS and DTGS, their
composites in PU matrix protect them from fragility and humidity susceptibility and made them for environmental friendly applications.
Nisha, R; Dr.Madhusoodanan, K N(Cochin University of Science And Technology, March , 2013)
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Abstract:
One of the main challenges in the development of metal-oxide gas sensors
is enhancement of selectivity to a particular gas. Currently, two general
approaches exist for enhancing the selective properties of sensors. The first one
is aimed at preparing a material that is specifically sensitive to one compound
and has low or zero cross-sensitivity to other compounds that may be present in
the working atmosphere. To do this, the optimal temperature, doping elements,
and their concentrations are investigated. Nonetheless, it is usually very difficult
to achieve an absolutely selective metal oxide gas sensor in practice. Another
approach is based on the preparation of materials for discrimination between
several analyte in a mixture. It is impossible to do this by using one sensor
signal. Therefore, it is usually done either by modulation of sensor temperature
or by using sensor arrays.
The present work focus on the characterization of n-type semiconducting
metal oxides like Tungsten oxide (WO3), Zinc Oxide (ZnO) and Indium oxide
(In2O3) for the gas sensing purpose. For the purpose of gas sensing thick as well
as thin films were fabricated. Two different gases, NO2 and H2S gases were
selected in order to study the gas sensing behaviour of these metal oxides. To
study the problem associated with selectivity the metal oxides were doped with
metals and the gas sensing characteristics were investigated.
The present thesis is entitled “Development of semiconductor metal oxide
gas sensors for the detection of NO2 and H2S gases” and consists of six chapters.
Description:
Department of instrumentation, Cochin University of Science And Technology
Dinesh Kumar, V P; Dr. Tessamma, Thomas(Cochin University of Science and Technology, April , 2008)
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Abstract:
The wealth of information available freely on the web and medical image databases poses a major problem for the end users: how to find the information needed? Content –Based Image Retrieval is the obvious solution.A standard called MPEG-7 was evolved to address the interoperability issues of content-based search.The work presented in this thesis mainly concentrates on developing new shape descriptors and a framework for content – based retrieval of scoliosis images.New region-based and contour based shape descriptor is developed based on orthogonal Legendre polymomials.A novel system for indexing and retrieval of digital spine radiographs with scoliosis is presented.
Description:
Department of Electronics,
Cochin University of Science and Technology
Sreekumar, A; Dr.Vijayakumar, K P(Cochin University of Science And Technology, November , 2007)
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Abstract:
In the present work, the author has designed and developed all types of solar
air heaters called porous and nonporous collectors. The developed solar air
heaters were subjected to different air mass flow rates in order to standardize
the flow per unit area of the collector. Much attention was given to
investigate the performance of the solar air heaters fitted with baffles. The
output obtained from the experiments on pilot models, helped the installation
of solar air heating system for industrial drying applications also. Apart from
these, various types of solar dryers, for small and medium scale drying
applications, were also built up. The feasibility of ‘latent heat thermal energy
storage system’ based on Phase Change Material was also undertaken. The
application of solar greenhouse for drying industrial effluent was analyzed in
the present study and a solar greenhouse was developed. The effectiveness
of Computational Fluid Dynamics (CFD) in the field of solar air heaters was
also analyzed. The thesis is divided into eight chapters.
Description:
Department of Physics, Cochin University of Science and Technology
Ananda Resmi, S; Dr. Tessamma, Thomas(Cochin University of Science And Technology, August 12, 2013)
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Abstract:
Cerebral glioma is the most prevalent primary brain tumor, which are
classified broadly into low and high grades according to the degree of malignancy.
High grade gliomas are highly malignant which possess a poor prognosis, and the
patients survive less than eighteen months after diagnosis. Low grade gliomas are
slow growing, least malignant and has better response to therapy. To date,
histological grading is used as the standard technique for diagnosis, treatment
planning and survival prediction.
The main objective of this thesis is to propose novel methods for automatic
extraction of low and high grade glioma and other brain tissues, grade detection
techniques for glioma using conventional magnetic resonance imaging (MRI)
modalities and 3D modelling of glioma from segmented tumor slices in order to
assess the growth rate of tumors. Two new methods are developed for extracting
tumor regions, of which the second method, named as Adaptive Gray level
Algebraic set Segmentation Algorithm (AGASA) can also extract white matter and
grey matter from T1 FLAIR an T2 weighted images. The methods were validated
with manual Ground truth images, which showed promising results. The developed
methods were compared with widely used Fuzzy c-means clustering technique and
the robustness of the algorithm with respect to noise is also checked for different
noise levels. Image texture can provide significant information on the
(ab)normality of tissue, and this thesis expands this idea to tumour texture grading
and detection. Based on the thresholds of discriminant first order and gray level cooccurrence
matrix based second order statistical features three feature sets were
formulated and a decision system was developed for grade detection of glioma
from conventional T2 weighted MRI modality.The quantitative performance
analysis using ROC curve showed 99.03% accuracy for distinguishing between
advanced (aggressive) and early stage (non-aggressive) malignant glioma. The
developed brain texture analysis techniques can improve the physician’s ability to
detect and analyse pathologies leading to a more reliable diagnosis and treatment of
disease. The segmented tumors were also used for volumetric modelling of tumors
which can provide an idea of the growth rate of tumor; this can be used for
assessing response to therapy and patient prognosis.
Description:
Department of Electronics
Cochin University of Science and Technology