Velukutty, K K; Dr.Wazir, Hasan Abdi(Cochin University of Science and Technology, February 15, 1982)
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Abstract:
An attempt is made by the researcher to establish a theory of discrete functions in the complex plane. Classical analysis q-basic theory, monodiffric theory, preholomorphic theory and q-analytic theory have been utilised to develop concepts like differentiation, integration and special functions.
Description:
Department of Mathematics and Statistics, Cochin University of Science & Technology
Maya, S S; Dr.Sunoj, S M(Cochin University of Science and Technology, October , 2007)
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Abstract:
The present study gave emphasis on characterizing continuous probability distributions
and its weighted versions in univariate set up. Therefore a possible work in this direction
is to study the properties of weighted distributions for truncated random variables in
discrete set up. The problem of extending the measures into higher dimensions as well as
its weighted versions is yet to be examined. As the present study focused attention to
length-biased models, the problem of studying the properties of weighted models with
various other weight functions and their functional relationships is yet to be examined.
Description:
Department of Statistics,
Cochin University of Science and Technology
Aype,Thomas P; Rajan,C K(Department of atmospheric sciences, 2005)
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Abstract:
This study focuses on the south –west monsoon rainfall over Kerala and its variability both on the spatial and temporal scales. The main objectives of the study are, interanual, long-term and decadal variabilities in MRF(monsoon rain fall),relationship between antecedent global circulation parameters, diurnal variability using data of a large number of stations in Kerala and the spatial distribution of rainfall under two large scale synoptic. Kerala gets nearly 190cm of rainfall during the south-west monsoon season 1st June to 30th September. This is more than twice the monsoon rainfall of India. A good part of kerala’s rainfall is caused by the orography of the Western Ghats Mountain ranges. The state receives 286cm of annual rainfall of which 68%is during the south-west monsoon season. The summer monsoon rainfall of Kerala shows a decreasing trend of 12.0%in 96 years. The study shows that the Intra Seasonal Oscillations(ISO) of the monsoon season has large interanual variability,some years having long period and other years having short period ISO. It is seen that Western Ghats has a strong control on the east west profile on the monsoon rainfall.
Kiran Kumar, V B; Dr.Narayanan Namboothiri, M N(Cochin University of Science and Technology, July 30, 2012)
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Abstract:
This thesis Entitled Spectral theory of bounded self-adjoint operators -A linear algebraic approach.The main results of the thesis can be classified as three different approaches to the spectral approximation problems. The truncation method and its perturbed versions are part of the classical linear algebraic approach to the subject. The usage of block Toeplitz-Laurent operators and the matrix valued symbols is considered as a particular example where the linear algebraic techniques are effective in simplifying problems in inverse spectral theory. The abstract approach to the spectral approximation problems via pre-conditioners and Korovkin-type theorems is an attempt to make the computations involved, well conditioned. However, in all these approaches, linear algebra comes as the central object.
The objective of this study is to discuss the linear algebraic techniques in the spectral theory of bounded self-adjoint operators on a separable Hilbert space. The usage of truncation method in approximating the bounds of essential spectrum and the discrete spectral values outside these bounds is well known. The spectral gap prediction and related results was proved in the second chapter. The discrete versions of Borg-type theorems, proved in the third chapter, partly overlap with some known results in operator theory. The pure linear algebraic approach is the main novelty of the results proved here.
Description:
Department of Mathematics,
Cochin University of Science and Technology
Leji, Latheef; Dr.Prathapachandra Kurup,M R(Cochin University of Science & Technology, September , 2007)
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Abstract:
The thesis is an introduction to evaluate the coordination behaviour of a few
compounds of our interest. The crucial aim of these investigations was to
synthesize and characterize some transition metal complexes using the ligands
benzaldehyde, 2-hydroxybenzaldehyde and 4-methoxybenzaldehyde N(4)-ring
incorporated thiosemicarbazones.The study involves a brief foreword of the metal
complexes of thiosemicarbazones including their bonding, stereochemistry and
biological activities.The different analytical and spectroscopic techniques used for
the analysis of the ligands and their complexes are discussed.It also deals with the synthesis and spectral characterization of the
thiosemicarbazones and single crystal X-ray diffraction study of one of them.Chapter 3 describes the synthesis, spectral characterization, single crystal X-ray
diffraction studies of copper(ll) complexes with ONS/NS donor
thiosemicarbazones. Chapter 4 deals with the synthesis, spectral characterization
and single crystal X-ray diffraction studies of nickel(II) complexes. Chapter 5
contains the synthesis, structural and spectral characterization of the cobalt(III)
complexes. Chapters 6 and 7 include the synthesis, structural and spectral
characterization of zinc(II) and cadmium(ll) complexes with ONS/NS donor
thiosemicarbazones.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Marthakutty, Joseph; Dr.Prathapachandra Kurup,M R(Cochin University Of Science And Technology, July 19, 2004)
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Abstract:
Aqua complex ions of metals must have existed since the appearance of
water on the earth, and the subsequent appearance of life depended on, and may
even have resulted from the interaction of metal ions with organic molecules.
Studies on the coordinating ability of metal ions with other molecules and anions
culminated in the theories of/\lfred Werner. Thereon the progress in the studies of
metal complex chemistry was rapid. Many factors, like the utility and economic
importance of metal chemistry, the intrinsic interest _in many of the compounds and
the intellectual challenge of the structural problems to be solved, have contributed
to this rapid progress. X—ray diffraction studies further accelerated the progress.
The work cited in this thesis was carried out by the author in the
Department of Applied Chemistry during 2001-2004. The primary aim of these
investigations was to synthesise and characterize some transition metal complexes
of 2-benzoylpyridine N(4)-substituted thiosemicarbazones and to study the
antimicrobial activities of the ligands and their metal complexes. The work is
divided into eight chapters
Description:
Department of Applied Chemistry
Cochin University of Science and Technology
Reena, T A; Dr.Prathapachandra Kurup,M R(Cochin University of Science & Technology, March , 2011)
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Abstract:
The present work is concentrated on the studies of two novel
semicarbazones, di-2-pyridyl ketone-N4-phenyl-3-semicarbazone (HL1) and
quinoline-2-carboxaldehyde-N4-phenyl-3-semicarbazone (HL2). The compositions
of these semicarbazones were determined by the CHN analyses. For the
characterization of these compounds we have used IR, UV and NMR spectral
studies. The molecular structure of quinoline-2-carboxaldehyde-N4-phenyl-3-
semicarbazone (HL2) was obtained by single crystal X-ray diffraction studies.
Also, we have synthesized Zn(II), Cd(II), Cu(II), Ni(II), Co(II) and Mn(II)
complexes of these semicarbazones, HL1 and HL2. These complexes were
characterized by various spectroscopic techniques, magnetic and conductivity
studies. We could isolate single crystals of some Zn(II) and Cd(II) compounds
suitable for X-ray diffraction studies. For other complexes we could not isolate
single crystals of good quality for single crystal X-ray diffraction studies.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Shiny Sara, Thomas; Dr. Subhash, N(Biophotonics Laboratory,Centre for Earth Science Studies, May , 2009)
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Abstract:
Dental caries persists to be the most predominant oral disease in spite of
remarkable progress made during the past half- century to reduce its prevalence.
Early diagnosis of carious lesions is an important factor in the prevention and
management of dental caries. Conventional procedures for caries detection involve
visual-tactile and radiographic examination, which is considered as “gold standard”.
These techniques are subjective and are unable to detect the lesions until they are
well advanced and involve about one-third of the thickness of enamel. Therefore, all
these factors necessitate the need for the development of new techniques for early
diagnosis of carious lesions. Researchers have been trying to develop various
instruments based on optical spectroscopic techniques for detection of dental caries
during the last two decades. These optical spectroscopic techniques facilitate noninvasive
and real-time tissue characterization with reduced radiation exposure to
patient, thereby improving the management of dental caries. Nonetheless, a costeffective
optical system with adequate sensitivity and specificity for clinical use is
still not realized and development of such a system is a challenging task.Two key techniques based on the optical properties of dental hard tissues are
discussed in this current thesis, namely laser-induced fluorescence (LIF) and diffuse
reflectance (DR) spectroscopy for detection of tooth caries and demineralization.
The work described in this thesis is mainly of applied nature, focusing on the analysis
of data from in vitro tooth samples and extending these results to diagnose dental
caries in a clinical environment. The work mainly aims to improve and contribute to
the contemporary research on fluorescence and diffuse reflectance for discriminating
different stages of carious lesions. Towards this, a portable and compact laser-induced
fluorescence and reflectance spectroscopic system (LIFRS) was developed for point
monitoring of fluorescence and diffuse reflectance spectra from tooth samples. The
LIFRS system uses either a 337 nm nitrogen laser or a 404 nm diode laser for the
excitation of tooth autofluorescence and a white light source (tungsten halogen lamp)
for measuring diffuse reflectance.Extensive in vitro studies were carried out on extracted tooth samples to
test the applicability of LIFRS system for detecting dental caries, before being tested
in a clinical environment. Both LIF and DR studies were performed for diagnosis of
dental caries, but special emphasis was given for early detection and also to
discriminate between different stages of carious lesions. Further the potential of LIFRS system in detecting demineralization and remineralization were also assessed.In the clinical trial on 105 patients, fluorescence reference standard (FRS)
criteria was developed based on LIF spectral ratios (F500/F635 and F500/F680) to
discriminate different stages of caries and for early detection of dental caries. The
FRS ratio scatter plots developed showed better sensitivity and specificity as compared
to clinical and radiographic examination, and the results were validated with the blindtests.
Moreover, the LIF spectra were analyzed by curve-fitting using Gaussian
spectral functions and the derived curve-fitted parameters such as peak position,
Gaussian curve area, amplitude and width were found to be useful for distinguishing
different stages of caries. In DR studies, a novel method was established based on
DR ratios (R500/R700, R600/R700 and R650/R700) to detect dental caries with
improved accuracy. Further the diagnostic accuracy of LIFRS system was evaluated
in terms of sensitivity, specificity and area under the ROC curve. On the basis of
these results, the LIFRS system was found useful as a valuable adjunct to the clinicians
for detecting carious lesions.
Teny Theresa, John; Dr.Vijayakumar, K P(Cochin University of Science and Technology, December , 2004)
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Abstract:
As emphasis towards sustainable and Renewable energy resources grows world-wide,interest in the capture and use of solar energy is increasing dramatically.Solar cells have been known and used for many years,but depletion of conventional energy resources resulted in the intensification of research on solar cells leading to new design and technique of fabrication.The current emphasis is directed towards high effiency inexpensive solar cells.This thesis includes deposition and characterization of CuInS2 and In2S3 thin films using chemical Spray Pyrolysis(CSP) technique.The optimum condition for these films to be used as absorber and buffer layer respectively in solar cells were thus found out.Solar cell with the stucture,ITO/CuInS2/In2S3/metal electrode was fabricated using these well-characterized films,which yielded an efficiency of 9.5%.
Description:
Department of Physics,
Cochin University of Science and Technology
Sajeesh, T. H.; Dr. K. P. Vijayakumar(Cochin University of Science and Technology, May 16, 2012)
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Abstract:
In the early 19th century, industrial revolution was fuelled mainly by
the development of machine based manufacturing and the increased use of
coal. Later on, the focal point shifted to oil, thanks to the mass-production
technology, ease of transport/storage and also the (less) environmental
issues in comparison with the coal!!
By the dawn of 21st century, due to the depletion of oil reserves and
pollution resulting from heavy usage of oil the demand for clean energy was
on the rising edge. This ever growing demand has propelled research on
photovoltaics which has emerged successful and is currently being looked
up to as the only solace for meeting our present day energy requirements.
The proven PV technology on commercial scale is based on silicon but the
recent boom in the demand for photovoltaic modules has in turn created a
shortage in supply of silicon. Also the technology is still not accessible to
common man. This has onset the research and development work on
moderately efficient, eco-friendly and low cost photovoltaic devices (solar
cells). Thin film photovoltaic modules have made a breakthrough entry in
the PV market on these grounds.
Thin films have the potential to revolutionize the present cost
structure of solar cells by eliminating the use of the expensive silicon wafers
that alone accounts for above 50% of total module manufacturing cost.
Sajeesh, T H; Dr.Vijayakumar, K P(Cochin University of Science and Technology, May , 2012)
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Abstract:
In the early 19th century, industrial revolution was fuelled mainly by
the development of machine based manufacturing and the increased use of
coal. Later on, the focal point shifted to oil, thanks to the mass-production
technology, ease of transport/storage and also the (less) environmental
issues in comparison with the coal!! By the dawn of 21st century, due to the depletion of oil reserves and pollution resulting from heavy usage of oil the demand for clean energy was
on the rising edge. This ever growing demand has propelled research on photovoltaics which has emerged successful and is currently being looked up to as the only solace for meeting our present day energy requirements. The proven PV technology on commercial scale is based on silicon but the recent boom in the demand for photovoltaic modules has in turn created a shortage in supply of silicon. Also the technology is still not accessible to common man. This has onset the research and development work on moderately efficient, eco-friendly and low cost photovoltaic devices (solar cells). Thin film photovoltaic modules have made a breakthrough entry in the PV market on these grounds. Thin films have the potential to revolutionize the present cost structure of solar cells by eliminating the use of the expensive silicon wafers that alone accounts for above 50% of total module manufacturing cost.Well developed thin film photovoltaic technologies are based on amorphous silicon, CdTe and CuInSe2. However the cell fabrication process using amorphous silicon requires handling of very toxic gases (like phosphene, silane and borane) and costly technologies for cell fabrication. In the case of other materials too, there are difficulties like maintaining stoichiometry (especially in large area films), alleged environmental hazards and high cost of indium. Hence there is an urgent need for the development of materials that are easy to prepare, eco-friendly and available in abundance. The work presented in this thesis is an attempt towards the development of a cost-effective, eco-friendly material for thin film solar cells using simple economically viable technique. Sn-based window and absorber layers deposited using Chemical Spray Pyrolysis (CSP) technique have been chosen for the purpose
Description:
Department of Physics
Cochin University of Science and Technology