Smitha, Sebastian; Ammini, Joseph(Cochin University Of Science And Technology, May , 2015)
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Abstract:
The present work is the study of filamentous algae in the paddy fields of Kuttanad and Kole lands of Kerala. This investigation was initiated by sampling of filamentous algae in Kuttanad during December 2010 to February 2011. A second phase of sampling was done from November 2011 to February 2012. The sampling
periodicity corresponded to the crop growth starting from field preparation through sowing, and continued till the harvest. Sampling locations were selected from the active paddy cultivation regions of the six agronomic zones of Kuttanad. The numbers of sampling locations were proportional to the area of each zone. Algae of the Kole lands were collected during from October 2011 to January 2012. It was observed that blue-green algae dominated in both Kuttanad and Kole lands. Thirty two species of blue-green algae and eight species of green algae were identified from Kuttanad. The highest number of algal species was observed from Kayal lands in Kuttanad throughout the cropping season. Among the thirty two species of blue-green algae twenty five species are nonheterocystous and seven species are heterocystous. Twenty eight species of blue-green and six species of green algae were identified from Kole lands, and highest number of species was observed in Palakkal throughout the cropping season. Among the twenty eight species of blue-green algae collected from Kole lands twenty one species are non-heterocystous, and only seven species are heterocystous filamentous algae. Blooms of Spirogyra were observed during the second phase of sampling in Kuttanad and also in the Kole lands. The results of the germination study revealed that the extract of Spirogyra sp. inhibited seed germination and reduced seedling vigour. The growth of the treated seedlings was evaluated by pot experiments. The results clearly showed that Spirogyra sp. can negatively affect the seed germination, seedling vigour, and the yield of rice.
Maria Starvin, A; Prasada Rao, T(CHEMICAL SCIENCES DIVISION REGIONAL RESEARCH LABORATORY (CSIR), July , 2007)
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Abstract:
Solid phase extraction (SPE) is a powerful technique for preconcentration/removal or separation of trace and ultra trace amounts of toxic and nutrient elements. SPE effectively simplifies the labour intensive sample preparation, increase its reliability and eliminate the clean up step by using more selective extraction procedures. The synthesis of sorbents with a simplified procedure and diminution of the risks of errors shows the interest in the areas of environmental monitoring, geochemical exploration, food, agricultural, pharmaceutical, biochemical industry and high purity metal designing, etc. There is no universal SPE method because the sample pretreatment depends strongly on the analytical demand. But there is always an increasing demand for more sensitive, selective, rapid and reliable analytical procedures. Among the various materials, chelate modified naphthalene, activated carbon and chelate functionalized highly cross linked polymers are most important. In the biological and environmental field, large numbers of samples are to be analysed within a short span of time. Hence, online flow injection methods are preferred as they allow extraction, separation, identification and quantification of many numbers of analytes. The flow injection online preconcentration flame AAS procedure developed allows the determination of as low as 0.1 µg/l of nickel in soil and cobalt in human hair samples. The developed procedure is precise and rapid and allows the analysis of 30 samples per hour with a loading time of 60 s. The online FI manifold used in the present study permits high sampling, loading rates and thus resulting in higher preconcentration/enrichment factors of -725 and 600 for cobalt and nickel respectively with a 1 min preconcentration time compared to conventional FAAS signal. These enrichment factors are far superior to hitherto developed on line preconcentration procedures for inorganics. The instrumentation adopted in the present study allows much simpler equipment and low maintenance costs compared to costlier ICP-AES or ICP-MS instruments.
Subi Jacob, George; Dr. Ajayaghosh, A(Regional Research Laboratory (CSIR), October , 2004)
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Abstract:
The main objective of the
present study is to have a detailed investigation on the gelation properties,
morphology and optical properties of small π-conjugated oligomers. For this purpose
we have chosen oligo(p-phenylenevinylene)s (OPVs), a class of molecules which
have received considerable attention due to their unique optical and electronic
properties. Though a large number of reports are available in the literature on the self-assembly properties of tailor made OPVs, none of them pertain to the design of
nanostructures based on organogels. In view of this, we aimed at the creation of
functional chromophoric assemblies of π-conjugated OPVs through the formation of
organogels, with the objective of crafting nanoscopic assemblies of different size and
shape thereby modulating their optical and electronic properties.In order to fulfill the above objectives, the design and synthesis of a variety of
OPVs with appropriate structural variations were planned. The design principle
involves the derivatization of OPVs with weak H-bonding hydroxymethyl end groups
and with long aliphatic hydrocarbon side chains. The noncovalent interactions in these
molecules were expected to lead the formation of supramolecular assembly and gels in
hydrocarbon solvents. In such an event, detailed study of gelation and extensive
analysis of the morphology of the gel structures were planned using advanced
microscopic techniques. Since OPVs are strongly fluorescent molecules, gelation is
expected to perturb the optical properties. Therefore, detailed study on the gelation
induced optical properties as a way to probe the nature and stability of the selfassembly
was planned. Apart from this, the potential use of the modulation of the
optical properties for the purpose of light harvesting was aimed. The approach to this
problem was to entrap an appropriate energy trap to the OPV gel matrix which may
lead to the efficient energy transfer from the OPV gel based donor to the entrapped
acceptor. The final question that we wanted to address in this investigation was the
creation of helical nanostructures through proper modification of the OPV backbone
With chiral handles.The present thesis is a detailed and systematic approach to the
realization of the above objectives which are presented in different chapters of the
thesis.
Vinod Kumar,P B; Thrivikraman,T(Department of Mathematics, September , 2001)
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Abstract:
The present study on chaos and fractals in general topological spaces. Chaos theory originated with the work of Edward Lorenz. The phenomenon which changes order into disorder is known as chaos. Theory of fractals has its origin with the frame work of Benoit Mandelbrot in 1977. Fractals are irregular objects. In this study different properties of topological entropy in chaos spaces are studied, which also include hyper spaces. Topological entropy is a measures to determine the complexity of the space, and compare different chaos spaces. The concept of fractals can’t be extended to general topological space fast it involves Hausdorff dimensions. The relations between hausdorff dimension and packing dimension. Regular sets in Metric spaces using packing measures, regular sets were defined in IR” using Hausdorff measures. In this study some properties of self similar sets and partial self similar sets. We can associate a directed graph to each partial selfsimilar set. Dimension properties of partial self similar sets are studied using this graph. Introduce superself similar sets as a generalization of self similar sets and also prove that chaotic self similar self are dense in hyper space. The study concludes some relationships between different kinds of dimension and fractals. By defining regular sets through packing dimension in the same way as regular sets defined by K. Falconer through Hausdorff dimension, and different properties of regular sets also.
Ancykutty, Joseph; Dr.Krishnamoorthy,A; Dr.Thrivikraman, T(Cochin University of Science and Technology, 2000)
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Abstract:
This thesis Entitled On Infinite graphs and related matrices.ln the last two decades (iraph theory has captured wide attraction as a Mathematical model for any system involving a binary relation. The theory is intimately related to many other branches of Mathematics including Matrix Theory Group theory. Probability. Topology and Combinatorics . and has applications in many other disciplines..Any sort of study on infinite graphs naturally involves an attempt to extend the well known results on the much familiar finite graphs. A graph is completely determined by either its adjacencies or its incidences. A matrix can convey this information completely. This makes a proper labelling of the vertices. edges and any other elements considered, an inevitable process. Many types of labelling of finite graphs as Cordial labelling, Egyptian labelling, Arithmetic labeling and Magical labelling are available in the literature. The number of matrices associated with a finite graph are too many For a study ofthis type to be exhaustive. A large number of theorems have been established by various authors for finite matrices. The extension of these results to infinite matrices associated with infinite graphs is neither obvious nor always possible due to convergence problems. In this thesis our attempt is to obtain theorems of a similar nature on infinite graphs and infinite matrices. We consider the three most commonly used matrices or operators, namely, the adjacency matrix
Description:
Department of mathematics, Cochin University of Science and Technology
Resmi, T; Dr. Lakshmi, B(Cochin University of Science and Technology, August 21, 2015)
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Abstract:
Queueing Theory is the mathematical study of queues or waiting lines.
Queues abound in every day life - in computer networks, in tra c islands,
in communication of electro-magnetic signals, in telephone exchange, in
bank counters, in super market checkouts, in doctor's clinics, in petrol
pumps, in o ces where paper works to be processed and many other
places.
Originated with the published work of A. K. Erlang in 1909 [16] on
congestion in telephone tra c, Queueing Theory has grown tremendously
in a century. Its wide range applications includes Operations Research,
Computer Science, Telecommunications, Tra c Engineering, Reliability
Theory, etc.
Dhanya, Shajin; Dr. B. Lakshmy(Cochin University of Science and Technology, November 12, 2015)
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Abstract:
Queueing theory is the mathematical study of ‘queue’ or ‘waiting lines’
where an item from inventory is provided to the customer on completion of
service. A typical queueing system consists of a queue and a server. Customers
arrive in the system from outside and join the queue in a certain way.
The server picks up customers and serves them according to certain service
discipline. Customers leave the system immediately after their service is completed.
For queueing systems, queue length, waiting time and busy period are of
primary interest to applications. The theory permits the derivation and calculation
of several performance measures including the average waiting time
in the queue or the system, mean queue length, traffic intensity, the expected
number waiting or receiving service, mean busy period, distribution of queue
length, and the probability of encountering the system in certain states, such
as empty, full, having an available server or having to wait a certain time to
be served.
Pramod,P K; Dr.Krishnamoorthy,A(Cochin University of Science & Technology, January , 2010)
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Abstract:
This thesis entitled' On
Queues with Interruptions and Repeat or Resumption of Service' introduces several
new concepts into queues with service interruption. It is divided into Seven chapters
including an introductory chapter. The following are keywords that we use
in this thesis: Phase type (PH) distribution, Markovian Arrival Process (MAP),
Geometric Distribution, Service Interruption, First in First out (FIFO), threshold
random variable and Super threshold random variable. In the second chapter we
introduce a new concept called the 'threshold random variable' which competes
with interruption time to decide whether to repeat or resume the interrupted service
after removal of interruptions. This notion generalizes the work reported so far
in queues with service interruptions. In chapter 3 we introduce the concept of what
is called 'Super threshold clock' (a random variable) which keeps track of the total
interruption time of a customer during his service except when it is realized before
completion of interruption in some cases to be discussed in this thesis and in other
cases it exactly measures the duration of all interruptions put together. The Super
threshold clock is OIl whenever the service is interrupted and is deactivated when service is rendered. Throughout this thesis the first in first out service discipline is
followed except for priority queues.
Description:
Department of Mathematics,
Cochin University of Science and Technology
Harikrishnan, K P; Dr.Nandakumaran,V M(Cochin University Of Science And Technology, November 3, 1989)
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Abstract:
Nature is full of phenomena which we call
"chaotic", the weather being a prime example.
What we mean by this is that we cannot predict it
to any significant accuracy, either because the
system is inherently complex, or because some of
the governing factors are not deterministic. However,
during recent years it has become clear that
random behaviour can occur even in very simple
systems with very few number of degrees of freedom,
without any need for complexity or indeterminacy.
The discovery that chaos can be generated even with
the help of systems having completely deterministic
rules - often models of natural phenomena - has
stimulated a lo; of research interest recently. Not
that this chaos has no underlying order, but it is
of a subtle kind, that has taken a great deal of
ingenuity to unravel. In the present thesis, the author
introduce a new nonlinear model, a ‘modulated’
logistic map, and analyse it from the view point of
‘deterministic chaos‘.
Description:
Department of Physics, Cochin University of
Science and Technology
Vijayakrishnan,S; Chakravarti,R S; Thrivikraman,T(Department of Mathematics,Faculty OF Science, 2002)
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Abstract:
The present study on some infinite convex invariants. The origin of convexity can be traced back to the period of Archimedes and Euclid. At the turn of the nineteenth centaury , convexicity became an independent branch of mathematics with its own problems, methods and theories. The convexity can be sorted out into two kinds, the first type deals with generalization of particular problems such as separation of convex sets[EL], extremality[FA], [DAV] or continuous selection Michael[M1] and the second type involved with a multi- purpose system of axioms. The theory of convex invariants has grown out of the
classical results of Helly, Radon and Caratheodory in Euclidean spaces. Levi gave the first general definition of the invariants Helly number and Radon number. The notation of a convex structure was introduced by Jamison[JA4] and that of generating degree was introduced by Van de Vel[VAD8]. We also prove that for a non-coarse convex structure, rank is less than or equal to the generating degree, and also generalize Tverberg’s theorem using infinite partition numbers. Compare the transfinite topological and transfinite convex dimensions
Sajeev, S Nair; Dr.Krishnamoorthy,A(Cochin University of Science and Technology, September 2, 2011)
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Abstract:
In this thesis we have developed a few inventory models in which items are served to the customers after a processing time. This leads to a queue of demand even when items are available. In chapter two we have discussed a problem involving search of orbital customers for providing inventory. Retrial of orbital customers was also considered in that chapter; in chapter 5 also we discussed retrial inventory model which is sans orbital search of customers. In the remaining chapters (3, 4 and 6) we did not consider retrial of customers, rather we assumed the waiting room capacity of the system to be arbitrarily large. Though the models in chapters 3 and 4 differ only in that in the former we consider positive lead time for replenishment of inventory and in the latter the same is assumed to be negligible, we arrived at sharper results in chapter 4. In chapter 6 we considered a production inventory model with production time distribution for a single item and that of service time of a customer following
distinct Erlang distributions. We also introduced protection of production and service stages and investigated the optimal values of the number of stages to be protected.
Description:
Department of Mathematics,
Cochin University of Science And Technology.
Remadevi,S; Narayanan Namboodiri,M N(Department of Mathematics,Faculty of Science, 2003)
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Abstract:
This study is to look the effect of change in the ordering of the Fourier system on Szegö’s classical observations of asymptotic distribution of eigenvalues of finite Toeplitz forms.This is done by checking proofs and Szegö’s properties in the new set up.The Fourier system is unconditional [19], any arbitrary ordering of the Fourier system forms a basis for the Hilbert space L2 [-Π, Π].Here study about the classical Szegö’s theorem.Szegö’s type theorem for operators in L2(R+) and check its validity for certain multiplication operators.Since the trigonometric basis is not available in L2(R+) or in L2(R) .This study discussed about the classes of orderings of Haar System in L2 (R+) and in L2(R) in which Szegö’s Type TheoreT Am is valid for certain multiplication operators.It is divided into two sections. In the first section there is an ordering to Haar system in L2(R+) and prove that with respect to this ordering, Szegö’s Type theorem holds for general class of multiplication operators Tƒ with multiplier ƒ ε L2(R+), subject to some conditions on ƒ.Finally in second section more general classes of ordering of Haar system in L2(R+) and in L2(R) are identified in such a way that for certain classes of multiplication operators the asymptotic distribution of eigenvalues exists.
Veena Gopalan, E; Dr.Anantharaman, M R(Cochin University of Science & Technology, June , 2009)
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Abstract:
This thesis lays importance in the preparation and characterization of a
few selected representatives of the ferrite family in the nanoregime. The candidates being manganese zinc ferrite and cobalt ferrite prepared by coprecipitation
and sol-gel combustion techniques respectively. The thesis not only
stresses importance on the preparation techniques and optimization of the reaction
conditions, but emphasizes in investigating the various properties namely
structural, magnetic and electrical. Passivated nickel nanocomposites are
synthesized using polystyrene beads and adopting a novel route of ion exchange
reduction. The structural and magnetic properties of these magnetic
nanocomposites are correlated. The magnetocaloric effect (MCE) exhibited by
these materials are also investigated with a view to finding out the potential of
these materials as magnetic refrigerants. Calculations using numerical methods
are employed to evaluate the entropy change on selected samples.
Description:
Department of Physics,
Cochin University of Science & Technology
Hysen, Thomas; Anantharaman, M R(Cochin University of Science and Technology, June , 2013)
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Abstract:
The development of new materials has been the hall mark of human civilization. The quest for making new devices and new materials has prompted humanity to pursue new methods and techniques that eventually has given birth to modern science and technology. With the advent of nanoscience and nanotechnology, scientists are trying hard to tailor materials by varying their size and shape rather than playing with the composition of the material. This, along with the discovery of new and sophisticated imaging tools, has led to the discovery of several new classes of materials like (3D) Graphite, (2D) graphene, (1D) carbon nanotubes, (0D) fullerenes etc. Magnetic materials are in the forefront of applications and have beencontributing their share to remove obsolescence and bring in new devices based on magnetism and magnetic materials. They find applications in various devices such as electromagnets, read heads, sensors, antennas, lubricants etc. Ferromagnetic as well as ferrimagnetic materials have been in use in the form of various devices. Among the ferromagnetic materials iron, cobalt and nickel occupy an important position while various ferrites finds applications in devices ranging from magnetic cores to sensors.
Description:
Department of Physics, Cochin University of Science and Technology
Abdul Sathar,E I; Muraleedharan Nair,K R(Department of Statistics, Faculty of Science, 2002)
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Abstract:
The present study focuses attention on defining certain measures of income inequality for the truncated distributions and characterization of probability distributions using the functional form of these measures, extension of some measures of inequality and stability to higher dimensions, characterization of bivariate models using the above concepts and estimation of some measures of inequality using the Bayesian techniques. The thesis defines certain measures of income inequality for the truncated distributions and studies the effect of truncation upon these measures. An important measure used in Reliability theory, to measure the stability of the component is the residual entropy function. This concept can advantageously used as a measure of inequality of truncated distributions. The geometric mean comes up as handy tool in the measurement of income inequality. The geometric vitality function being the geometric mean of the truncated random variable can be advantageously utilized to measure inequality of the truncated distributions. The study includes problem of estimation of the Lorenz curve, Gini-index and variance of logarithms for the Pareto distribution using Bayesian techniques.
George, Joseph; Zakkariya, K A(Cochin University Of Science And Technology, October , 2015)
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Abstract:
The aim of this study is to investigate the role of operational flexibility for
effective project management in the construction industry.
The specific objectives are to:
a) Identify the determinants of operational flexibility potential
in construction project management
b) Investigate the contribution of each of the determinants to
operational flexibility potential in the construction industry
c) Investigate on the moderating factors of operational
flexibility potential in a construction project environment
d) Investigate whether moderated operational flexibility
potential mediates the path between predictors and effective
construction project management
e) Develop and test a conceptual model of achieving
operational flexibility for effective project management
The purpose of this study is to findout ways to utilize flexibility inorder to manage uncertain project environment and ultimately achieve effective project management. In what configuration these operational flexibility determinants are demanded by construction project environment in order to achieve project success. This research was conducted in three phases, namely: (i) exploratory phase (ii) questionnaire development phase; and (iii) data collection and analysis phase. The study needs firm level analysis and therefore real estate developers who are members of CREDAI, Kerala Chapter were considered. This study provides a framework on the functioning of operational flexibility, offering guidance to researchers and practitioners for discovering means to gain operational flexibility in construction firms. The findings provide an empirical understanding on kinds of resources and capabilities a construction firm must accumulate to respond flexibly to the changing project environment offering practitioners insights into practices that build firms operational flexibility potential. Firms are dealing with complex, continuous changing and uncertain environments due trends of globalization, technical changes and innovations and changes in the customers’ needs and expectations. To cope with the increasingly uncertain and quickly changing environment firms strive for flexibility. To achieve the level of flexibility that adds value to the customers, firms should look to flexibility from a day to day operational perspective. Each dimension of operational flexibility is derived from
competences and capabilities. In this thesis only the influence on customer satisfaction and learning exploitation of flexibility dimensions which directly add value in the customers eyes are studied to answer the followingresearch questions: “What is the impact of operational flexibility on customer satisfaction?.” What are the predictors of operational flexibility in construction industry? .These questions can only be answered after answering the questions like “Why do firms need operational flexibility?” and “how can firms achieve operational flexibility?” in the context of the construction industry. The need for construction firms to be flexible, via the effective utilization of organizational resources and capabilities for improved responsiveness, is important because of the increasing rate of changes in the business environment within which they operate. Achieving operational flexibility is also important because it has a significant correlation with a project effectiveness and hence a firm’s turnover. It is essential for academics and practitioners to recognize that the attainment of operational flexibility involves different types namely: (i) Modification (ii) new product development and (iii) demand management requires different configurations of predictors (i.e., resources, capabilities and strategies). Construction firms should consider these relationships and implement appropriate management practices for developing and configuring the right kind of resources, capabilities and strategies towards achieving different operational flexibility types.
Alex,Mathew; Dr.Madhusoodanan, K N(Cochin University of Science and Technology, June , 2004)
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Abstract:
The thesis provides an overall review and introduction to amorphous semiconductors, followed by a brief discussion on the important structural models proposed for chalcogenide glasses and their electrical, optional and thermal properties. It also gives a brief description of the Physics of thin films, ion implantation and Photothermal Deflection Spectroscopy. A brief description of the experimental setup of a photothermal deflection spectrometer and the details of the preparation and optical characterization of the thin film samples. It deals with the employment of the subgap optional absorption measurement by PDS to characterize the defects, amorphization and annealing behavior in silicon implanted with B+ ions and the profiles of ion range and vacancy distribution obtained by the TRIM simulation. It reports the results of all absorption measurements by PDS in nitrogen implanted thin film samples of Ge-Se and As-Se systems
Joseph, Lyjo K; Dr. Radhakrishnan, P; Dr.Nampoori,V P N(Cochin University of Science & Technology, November , 2009)
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Abstract:
Nondestructive photothermal methods as well as optical absorption and fluorescence spectroscopy are utilized to characterise three different materials, both thermally and optically. The possibility of using montmorillonite clay minerals, after textile waste-water treatment, is investigated for further applications. The laser induced luminescence studies and thermal characterisation of certain rare earth titanates prepared by self propagating high temperature synthesis method are also presented. Moreover, effort is made to characterise rare earth doped sol gel silica glasses with the help of these nondestructive techniques.
Description:
International School of Photonics, Cochin University of Science and Technology
Lyjo, Joseph K; Dr. Radhakrishnan, P(Cochin University of Science And Technology, November , 2009)
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Abstract:
The advent of high optical quality transparent nano—structured glasses, the so-called transparent glass ceramics or vitroceramics disclosed the possibility of producing nano-sized photonic devices based on rare-earth doped up—converters. Transparent glass ceramics have been investigated as hosts for lanthanide ions envisioning the production of materials that are easy to shape and with high performance for photonic applications. Rare earth doped glasses have been extensively studied due to their potential applications in optical devices such as solid state lasers and optical fibers. Various photothermal and optical techniques have been successfully applied for the thermal and optical characterization of these rare earth doped materials. In the present thesis, the effective thermal parameters like thermal diffusivity and thermal effusivity of complex materials for various applications have been investigated using photothermal methods along with their optical characterization utilising the common optical absorption as well as fluorescence spectroscopic techniques. These sensitive optical procedures are also essential for exploiting these materials for further photonic applications.
Description:
School of photonics, Cochin University of Science And Technology
Harilal, S S; Girijavallabhan, C P(Cochin University of Science and Technology, 1997)
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Abstract:
This thesis is entitled “OPTICAL EMISSION DIAGNOSTICS OF LASER PRODUCED PLASMA FROM GRAPHITE AND YBa2Cu3O7. The work presented in this thesis covers the experimental results on the plasma produced with moderately high power laser with irradiance range in between 10 GW cm 2 to 100 GW cm -2. The characterization of laser produced plasma from solid targets viz. graphite and high temperature superconducting material like YBa2Cu3O7 have been carried out. The fundamental frequency from a Q - switched Nd: YAG laser with 9 ns pulse
duration is used for the present studies. Various optical emission emission diagnostic techniques were employed for the the characterization of the LPP which include emission spectroscopy, time resolved studies, line broadening method etc. In order to understand the physical nature of the LPP like recombination, collisional excitation and the laser interaction with plasma, the time resolved studies offer the most logical approach
Jude Martin, Mendez; Dr.George, K E(Cochin University of Science & Technology, October , 2009)
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Abstract:
This study was undertaken in order to upgrade blends of HDPE and
PP, two of the most widely used standard plastics so as to widen their
application spectrum. Dicumyl peroxide was used as the modifier for the
upgradation. Optimum concentration of dicumyl peroxide required for
modification was detennined by measurement of mechanical, rheological,
thermal and morphological properties. Selected blends were used to prepare
recyclable composites with nylon clothes by compression moulding. The
composites were characterized by measurement of mechanical and thermal
properties. The composites were recycled and the mechanical propertics of
the recycled material were determined.
Description:
Dept.of Polymer Science and Rubber Technology,
Cochin University of Science and technology
Rinku Mariam, Thomas; Dr.George, K E; Dr.Mathew, K T; Dr.Prathapan, S(Cochin University of Science & Technology, May , 2005)
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Abstract:
The thesis deals with the preparation and dielectric characterization of
Poly aniline and its analogues in ISM band frequency of 2-4 GHz that includes part
of the microwave region (300 MHz to 300 GHz) of the electromagnetic spectrum
and an initial dielectric study in the high frequency [O.05MHz-13 MHz].
PolyaniIine has been synthesized by an in situ doping reaction under different
temperature and in the presence of inorganic dopants such as HCl H2S04, HN03,
HCl04 and organic dopants such as camphorsulphonic acid [CSA],
toluenesulphonic acid {TSA) and naphthalenesulphonic acid [NSA]. The variation
in dielectric properties with change in reaction temperature, dopants and
frequency has been studied. The effect of codopants and microemulsions on the dielectric properties has also been studied in the ISM band. The ISM band of
frequencies (2-4 GHz) is of great utility in Industrial, Scientific and Medical (ISM)
applications. Microwave heating is a very efficient method of heating dielectric
materials and is extensively used in industrial as well as household heating
applications.
Description:
Department of
Polymer Science and Rubber Technology,Cochin University of Science and
Technology
Rahana, Yoosuf; Dr.Jayaraj, M K(Cochin University of Science & Technology, October , 2007)
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Abstract:
Two stage processes consisting of precursor preparation by thermal
evaporation followed by chalcogenisation in the required atmosphere is
found to be a feasible technique for the PV materials such as n-Beta In2S3,
p-CulnSe2, p-CulnS2 and p-CuIn(Sel_xSx)2. The growth parameters such as
chalcogenisation temperature and duration of chalcogenisation etc have been
optimised in the present study.Single phase Beta-In2S3 thin films can be obtained by sulfurising the indium
films above 300°C for 45 minutes. Low sulfurisation temperatures required
prolonged annealing after the sulfurisation to obtain single phase Beta-1n2S3,
which resulted in high material loss. The maximum band gap of 2.58 eV was
obtained for the nearly stoichiometric Beta-In2S3 film which was sulfurised at
350°C. This wider band gap, n type Beta-In2S3 can be used as an alternative to
toxic CdS as window layer in photovoltaics .The systematic study on the structural optical and electrical properties of
CuInSe2 films by varying the process parameters such as the duration of
selenization and the selenization temperature led to the conclusion that for
the growth of single-phase CuInSe2, the optimum selenization temperature is
350°C and duration is 3 hours. The presence of some binary phases in films
for shorter selenization period and lower selenization temperature may be
due to the incomplete reaction and indium loss. Optical band gap energy of
1.05 eV obtained for the films under the optimum condition.In order to obtain a closer match to the solar spectrum it is desirable to
increase the band gap of the CulnSe2 by a few meV . Further research
works were carried out to produce graded band gap CuIn(Se,S)2 absorber
films by incorporation of sulfur into CuInSe2. It was observed that when the
CulnSe2 prepared by two stage process were post annealed in sulfur atmosphere, the sulfur may be occupying the interstitial positions or forming
a CuInS2 phase along with CuInSe2 phase. The sulfur treatment during the
selenization process OfCu11 ln9 precursors resulted in Culn (Se,S)2 thin films.
A band gap of 1.38 eV was obtained for the CuIn(Se,S)2.The optimised thin films n-beta 1n2S3, p-CulnSe2 and p-Culn(Sel-xSx)2 can be
used for fabrication of polycrystalline solar cells.
Description:
Department of Physics,
Cochin University of Science and Technology
Vineetha, C P; Dr Babu, C.A(Cochin University of Science and Technology, June 22, 2015)
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Abstract:
The renewable energy sources (RES) will play a vital role in the
future power needs in view of the increasing demand of electrical
energy and depletion of fossil fuel with its environmental impact. The
main constraints of renewable energy (RE) generation are high capital
investment, fluctuation in generation and requirement of vast land area.
Distributed RE generation on roof top of buildings will overcome these
issues to some extent.
Any system will be feasible only if it is economically viable and
reliable. Economic viability depends on the availability of RE and
requirement of energy in specific locations. This work is directed to
examine the economic viability of the system at desired location and
demand.
Ajitha, S; Dr.Sugunan, S(Cochin University of Science and Technology, September , 2008)
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Abstract:
Mesoporous materials are of great interest to the materials community because of their potential applications for catalysis,separation of large molecules,medical implants,semiconductors,magnetoelectric devices.The thesis entitled 'Ordered Mesoporous Silica as supports for immobilization of Biocatalyst' presents how the pore size can be tuned without the loss in ordered structure for the entrapment of an industially important biocatalyst-amylase.Immobilization of enzymes on ordered mesoporous material has triggered new ooportunities for stabilizing enzymes with improved intrinsic and operational stabilities.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology
Kannan, V; Dr. Sreekumar, K(Cochin University of Science & Technology, August , 2011)
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Abstract:
Catalysis is a technologically important field which determines the quality of life in future. Catalyst research in pharmaceutical industry,fine chemical synthesis and emission control demands supported catalysts in bulk quantities.In the present work it was observed that clay supported catalysts mentioned in various chapters could also be used for the synthesis of similar molecules. The K10Ti catalyst can be used for the synthesis similar substituted imidazole derivatives under solvent free conditions and synthetically important Mannich bases of substrates containing various substitutes.Al-pillared saponite can be used for acetalation of other polyhydroxy compounds like glycerol,mannitol etc.Cu-Pd KSF catalyst has found application in C-C bond forming reactions which can be applied to other reactions and similar methods can be adopted for the synthesis of other catalyst by changing the transition metals. Montmorillonite K10 catalysed synthesis of triarylpyridines can be extended to the synthesis tetrasubstuted pyroles.K10Ti can also be utilized for the synthesis of similar heterocycles.
Description:
Dept.of Applied Chemistry,Cochin University of Science and Technology
Jacob,T V; Dr.Ramachandra, Poduval P(Cochin University of Science and Technology, March 30, 1990)
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Abstract:
The term 'organisation' is used in different contexts. In this study,
organisation is considered as a 'socio—technical system. Alienation, as a term and as a theme, are found in many writings from very early times. But the concept and emphasis differ. The writers who have explained alienation includes theologians, philosophers, anthropologists, economists, political scientists, historians, psychologists and sociologists
Description:
School of Management Studies, Cochin University of
Science and Technology
Srinivasa, Gopal T K; Dr. Hridayanathan, C(Cochin University of Science and Technology, April 28, 1993)
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Abstract:
Packaging is important not only in extending the shellife of fish and fishery products but also improving their marketability. In the recent years, significant development have taken place in the packaging industry. During the past decade in India, there is almost a packaging revolution with the availability of variety packaging materials, thus generating better packaging consciousness in other producer/manufacturing industries. But unfortunately, such realisation is not forthcoming in the fisheries sector and packaging techniques for local and export trade continues to be on traditional lines with their inherent drawbacks and limitations. Better packaging ensures improved quality and presentation of the products and ensures higher returns to the producer. Among several packaging materials used in fishery industry, ISI specifications had been formulated only for corrugated fibre board boxes for export of seafoods and froglegs. This standard was formulated before containersiation came into existance in the export of marine products. Before containerisation, the standards were stringent in view of the rough handling, transportation and storage. Two of the common defects reported in the master cartons exported from India are low mechanical strength and tendency to get wet. They are weakened by the deposits of moisture caused by temperature fluctuations during loading, unloading and other handling stages. It is necessary to rectify the above defects in packaging aquatic products and hence in the present study extensive investigations are carried out to find out the reasons for the damage of master cartons, to evolve code of practice for the packaging oi frozen shrimp for exports, development of alternative style of packaging for the shipping container, development of suitable consumer packaging materials for fish soup powder, cured dried mackeral, fish pickles in oil and frozen shrimp. For the development of suitable packaging materials, it is absolutely essential to know the properties of packaging materials, effect of different packaging materials on theirshelf life and their suitability for food contact applications.
Description:
Department
of Industrial Fisheries, Cochin University of Science and
Technology