Mechanical properties and thermal degradation characteristics of natural rubber compounds
captaining coconut oil were compared with that of a control compound containing naphthenic oil.
Cure time was marginally lower in the case of coconut oil mixes, probably due to the presence of
free fatty acids. Tensile strength , tear strength, resilience and abrasion resistance were better than
the naphthenic oil-based compounds . Compression set and hardness were marginally inferior
The coconut oil mixes had a crosslink density comparable to that of the reference compound.
Thermal studies showed that the temperature of initiation of degradation was increased by 10°C
and the temperature at which the peak rate of degradation occured was increased by 7°C. The
peak rate of degradation was compa rable to the control compound.
Subramania Prasad, C K; Dr.Benny Mathews, Abraham(Cochin University of Science And Technology, December , 2013)
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Abstract:
At this era of energy crisis and resource depletion, availability
of conventional materials throughout the year in quantity and quality,
pose a hectic problem for the builders. Adding fuel to the fire, the
demand of these materials increases day by day, since the housing
and habitat requirements exponentially increase time to time. There is
an international concern over this crisis and researchers are
reorienting themselves, so as to evolve appropriate masonry units,
using locally available cheap materials and technology. The concept
of green material and construction has been well conceived in the
research so that marginal materials and unskilled labour can be
employed for the mass production of building blocks. In this context,
considering earth as a sustainable material, there is a growing interest
in the use of it, as a modern construction material. Solid waste
management is one of the current major environmental concerns in
our country. Our country is left with millions of cubic metre of waste
plastics. One of the methods to satisfactorily address this solid waste
management and the environmental issues is to suitably accommodate
the waste in some form (as fibres). Their employability in block making
in the form of fibres (plastic fibre- mud blocks) can be investigated
through a fundamental research. Also, the review of the existing
literature shows that most studies on natural fibres are focussed on cellulose based/ vegetable fibres obtained from renewable plant
resources except in very few cases, where animal fibre, plastic fibre
and polystyrene fabric were used.
At this context, for the plastic fibre-mud blocks to be more
widely applicable, a systematic quantification of the relevant physical
and mechanical properties of the fibre masonry units is crucial, to
enable an objective evaluation of the composite material’s response to
actual field condition. This research highlights the salient
observations from the detailed investigation of a systematic study on
the effect of embedded fibres, made of plastic wastes on the
performance of stabilised mud blocks.
Description:
School of Engineering,
Cochin University of Science and Technology
Mariamma, Joseph; Dr.Babu,Jose T(Cochin University of Science & Technology, November , 2010)
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Abstract:
Soil moisture plays a cardinal role in sustaining eclological balance and
agricultural development – virtually the very existence of life on earth. Because of the
growing shortage of water resources, we have to use the available water most efficiently
by proper management. Better utilization of rainfall or irrigation management depends
largely on the water retention characteristics of the soil.Soil water retention is essential to life and it provides an ongoing supply of water
to plants between periods of irrigation so as to allow their continued growth and
survival.It is essential to maintain readily available water in the soil if crops are to sustain
satisfactory growth. The plant growth may be retarded if the soil moisture is either
deficient or excessive. The optimum moisture content is that moisture which leads to
optimum growth of plant. When watering is done, the amount of water supplied should
be such that the water content is equal to the field capacity that is the water remained in
the saturated soil after gravitational drainage. Water will gradually be utilized
consumptively by plants after the water application, and the soil moisture will start
falling. When the water content in the soil reaches the value known as permanent
wilting point (when the plant starts wilting) fresh dose of irrigation may be done so that
water content is again raised to the field capacity of soil.Soil differ themselves in some or all the properties depending on the difference
in the geotechnical and environmental factors. Soils serve as a reservoir of the nutrients
and water required for crops.Study of soil and its water holding capacity is essential for the efficient
utilization of irrigation water. Hence the identification of the geotechnical parameters
which influence the water retention capacity, chemical properties which influence the
nutrients and the method to improve these properties have vital importance in irrigation
/ agricultural engineering. An attempt in this direction has been made in this study by
conducting the required tests on different types of soil samples collected from various
locations in Trivandrum district Kerala, with and without admixtures like coir pith,
coir pith compost and vermi compost. Evaluation of the results are presented and a
design procedure has been proposed for a better irrigation scheduling and management.
Description:
Division of Civil Engineering, Cochin University of Science and Technology
Raji, George; Dr.Jhonson, T P(Cochin University of Science And Technology, September 4, 2013)
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Abstract:
The thesis is divided into nine chapters including introduction.
Mainly
we determine ultra L-topologies in the lattice of L- topologies and
study their properties.
We nd some sublattices in the lattice of L-topologies and study
their properties.
Also we study the lattice structure of the set of all L-closure operators
on a set X.
Description:
Department of Mathematics
Cochin University of Science and Technology
Rajeswari Devi, M B; Dr.Jathavedan, M(Cochin University of Science and Technology, December , 2006)
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Abstract:
In this thesis an attempt is made to study vortex knots based on the work of
Keener . It is seen that certain mistakes have been crept in to the details of this
paper. We have chosen this study for an investigation as it is the first attempt to
study vortex knots. Other works had given attention to this. In chapter 2 we have
considered these corrections in detail. In chapter 3 we have tried a simple extension by introducing vorticity in the evolution of vortex knots. In chapter 4 we have introduced
a stress tensor related to vorticity. Chapter 5 is the general conclusion.Knot theory is a branch of topology and has been developed as an independent
branch of study. It has wide applications and vortex knot is one of them. As pointed
out earlier, most of the studies in fluid dynamics exploits the analogy between vorticity
and magnetic induction in the case of MHD. But vorticity is more general than magnetic
induction and so it is essential to discuss the special properties of vortex knots,
independent of MHD flows. This is what is being done in this thesis.
Description:
Dept.of Mathematics,
Cochin University of Science and Technology
Sunil,K Narayanankutty(Taylor & Francis Inc., March 26, 2001)
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Abstract:
Cure characteristics and mechanical properties of styrene butadiene rubber
reclaimed rubber blends were studied. The blends showed improved processability,
as indicated by the minimum torque values. Cure characteristics like minimum
torque, (maximum-minimum) torque, cure time and cure rate decreased in the
presence of reclaimed rubber. Tensile strength, tear strength, elongation at break
were higher for blends. Resilience decreased with reclaim content. Compression set
and abrasion loss were higher in the blends.
Poulose Jacob,K; Vimina, E R(International Journal of Computer Science Issues (IJCSI), January 1, 2013)
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Abstract:
This paper proposes a content based image retrieval (CBIR) system using the local colour and texture features of selected image sub-blocks and global colour and shape features of the image. The image sub-blocks are roughly identified by segmenting the image into partitions of different configuration, finding the edge density in each partition using edge thresholding, morphological dilation. The colour and texture features of the identified regions are computed from the histograms of the quantized HSV colour space and Gray Level Co- occurrence Matrix (GLCM) respectively. A combined colour and texture feature vector is computed for each region. The shape features are computed from the Edge Histogram Descriptor (EHD). A modified Integrated Region Matching (IRM) algorithm is used for finding the minimum distance between the sub-blocks of the query and target image. Experimental results show that the proposed method provides better retrieving result than retrieval using some of the existing methods
Description:
International Journal of Computer Science Issues (IJCSI)
Sasi Kumar, P R; Nampoori, V P N; Vallabhan, C P G(Elsevier, December 26, 1994)
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Abstract:
We report the experimental observation of subcritical Hopf bifurcation and the existence of non-oscillating “windows” in the dynamics of a Ne-Nd hollow cathode discharge current as the control parameter.
Philip,Mathew; Dr.Ravindranatha Menon,N(Cochin University of Science and Technology, August , 1990)
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Abstract:
The present scientific investigation of the effects of copper, mercury and cadmium has focussed on their effects on two commercially important marine bivalve species, Perna indica (brown mussel) and Donax incarnatus (wedge clam), conspicuous representatives of the tropical intertidal areas. The investigation centred around delineating the cause and effects of heavy metal stress, individually and in combination on these species under laboratory conditions. A clear understanding of the cause and effect can be had only if laboratory experiments are conducted employing sub-lethal concentrations of the above toxicants. Therefore, during the course of the investigation, sub-lethal concentrations of copper, mercury and cadmium were employed to assess the concentration dependent effects on survival, ventilation rate, O:N ratio and tissues. The results obtained are compared with the already available information and partitioned in sections to make a meaningful presentation.The thesis is presented in five chapters comprising INTRODUCTION, ACUTE TOXICITY, VENTILATION RATE, OXYGEN : NITROGEN RATIO and HISTOPATHOLOGY. Each chapter has been divided into various sections such as INTRODUCTION, REVIEW OF LITERATURE, MATERIAL AND METHODS, RESULTS and DISCUSSION
Description:
Head, Division of Marine Biology, Microbiology and
Biochemistry, School of Marine Sciences, Cochin University
of Science and Technology
Resmi, E A; Dr.Mohanakumar,K(Cochin University Of Science And Technology, September , 2012)
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Abstract:
The stratospheric warming events are categorized into major and minor
warming depending on the temperature increase in the polar stratosphere.
The warming is called a ‘major’, when the polar temperature increases
poleward from 60 degree latitude and followed by a reversal in the zonal
wind at 10 hPa (~32 Km). Usually major warming events are associated
with the displacement of polar vortex from high to mid latitudes or the
splitting of vortices in to two. The warming is called a "Minor", when the
polar temperature increases more than 25 degree in a period of a week or
less, at any stratospheric level with less intensified easterly wind anomalies. The stratospheric warmings generated during the transition
period of winter to spring are called final warmings. The warming events
observed in the early winter period (November to early December) over
Canadian region are called Canadian warmings. There is strong
interaction between stratosphere and troposphere during SSW period over
high and low latitudes regions.
The thesis consists of 7 chapters
Description:
Department of Atmospheric Sciences, Cochin
University of Science and Technology
Sunajadevi, K R; Sugunan, S(Elsevier, September , 2005)
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Abstract:
Titania, sulfated titania and chromium loaded sulfated titania were prepared by sol–gel method and characterized using different technique. Phenol is nitrated regioselectively by nitric acid using chromium loaded sulfated titania catalysts. A remarkable ortho selectivity is observed in solid state nitration to yield exclusively ortho-nitrophenol. Compared to the conventional process, phenol nitration over solid acid catalyst is a clean and environment friendly process. Catalytic activity well correlates with the Brönsted acid sites of these catalysts.
Rosily, A V; Dr.Chandramohanakumar, N(Cochin University of Science & Technology, December , 2002)
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Abstract:
Sulphur is a non conservative major element and is the most active species in the redox processes in nature, especially in aquatic environment . The varying oxidative states from-2 to +6 make it possible to enter into many of the biogeochemical processes. Thus the history, present and future of the chemical composition and behaviour of the natural aquatic systems and sediments have footprints of the sulphur chemistry.Mangroves are considered to be the most productive, fishery supportive ecosystem operating in the intertidal regions. The interlinking of the mangroves with the sulphur chemistry is attempted here.
Description:
Department of Chemical Oceanography, Cochin University of Science and Technology