Santhosh, B; Dr.Nandakumar, C G(Cochin University of Science & Technology, December , 2010)
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Abstract:
Three dimensional (3D) composites are strong contenders for the structural applications in situations like aerospace,aircraft and automotive industries where multidirectional thermal and mechanical stresses exist. The presence of reinforcement along the thickness direction in 3D composites,increases the through the thickness stiffness and strength properties.The 3D preforms can be manufactured with numerous complex architecture variations to meet the needs of specific applications.For hot structure applications Carbon-Carbon(C-C) composites are generally used,whose property variation with respect to temperature is essential for carrying out the design of hot structures.The thermomechanical behavior of 3D composites is not fully understood and reported.The methodology to find the thermomechanical properties using analytical modelling of 3D woven,3D 4-axes braided and 3D 5-axes braided composites from Representative Unit Cells(RUC's) based on constitutive equations for 3D composites has been dealt in the present study.High Temperature Unidirectional (UD) Carbon-Carbon material properties have been evaluated using analytical methods,viz.,Composite cylinder assemblage Model and Method of Cells based on experiments carried out on Carbon-Carbon fabric composite for a temparature range of 300 degreeK to 2800degreeK.These properties have been used for evaluating the 3D composite properties.From among the existing methods of solution sequences for 3D composites,"3D composite Strength Model" has been identified as the most suitable method.For thegeneration of material properies of RUC's od 3D composites,software has been developed using MATLAB.Correlaton of the analytically determined properties with test results available in literature has been established.Parametric studies on the variation of all the thermomechanical constants for different 3D performs of Carbon-Carbon material have been studied and selection criteria have been formulated for their applications for the hot structures.Procedure for the structural design of hot structures made of 3D Carbon-Carbon composites has been established through the numerical investigations on a Nosecap.Nonlinear transient thermal and nonlinear transient thermo-structural analysis on the Nosecap have been carried out using finite element software NASTRAN.Failure indices have been established for the identified performs,identification of suitable 3D composite based on parametric studies on strength properties and recommendation of this material for Nosecap of RLV based on structural performance have been carried out in this Study.Based on the 3D failure theory the best perform for the Nosecap has been identified as 4-axis 15degree braided composite.
Description:
Dept.of Ship Technology,Cochin University of Science and Technology
Mini Devi, B; Dr. Rajan Pillai, C V(Cochin University of Science and Technology, February 15, 2006)
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Abstract:
The title of the study is ''Toxicology Literature: An Informetric Analysis".In the field of Toxicology, the interdisciplinary research resulted in 'information fragmentation' of the basic subject to environmental, medical and economic toxicology. The interest in collaborative research resulted in the transdisciplinary growth of Toxicology which ultimately resulted in the scatter of literature.For the purpose of present study Toxicology is defined as the physical and chemical aspects of all poisons affecting environmental, economical and medical aspects of human life. Informetrics is "the use and development of a variety of measures to study and analyse several properties of information in general and documents in particular."The present study fled light on the main fields of Toxicology research as well as the important primary journals through which the results are being published. The authorshippattern, subject-wise scatter, country-wise, language-wise and growth pattern, self-citation, bibliographic coupling of the journals were studied. The study will be of great use in forrnulatinq the acquisition policy of documents in a library. The present study is useful in identifying obsolate journals so that they can be discarded from the collection
Description:
Department of Computer Science, Cochin University of Science and Technology
Alex,A V; Jacob, Philip(Cochin University of Science and Technology, May , 2001)
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Abstract:
Ultrasonic is a good tool to investigate the elastic properties of crystals. It enables one to determine all the elastic constants, Poisson’s ratios, volume compressibility and bulk modulus of crystals from velocity measurements. It also enables one to demonstrate the anisotropy of elastic properties by plotting sections of the surfaces of phase velocity, slowness, group velocity, Young’s modulus and linear compressibility along the a-b, b-c and a-c planes. They also help one to understand more about phonon amplification and help to interpret various phenomena associated with ultrasonic wave propagation, thermal conductivity, phonon transport etc. Study of nonlinear optical crystals is very important from an application point of view. Hundreds of new NLO materials are synthesized to meet the requirements for various applications. Inorganic, organic and organometallic or semiorganic classes of compounds have been studied for several reasons. Semiorganic compounds have some advantages over their inorganic and inorganic counterparts with regard to their mechanical properties. High damage resistance, high melting point, good transparency and non-hygroscopy are some of the basic requirements for a material to be suitable for device fabrication. New NLO materials are being synthesized and investigation of the mechanical and elastic properties of these crystals is very important to test the suitability of these materials for technological applications
Prabha, C; Dr.Pillai, P R S(Cochin University of Science And Technology, July 24, 2013)
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Abstract:
Underwater target localization and tracking attracts tremendous research interest due to various impediments to the estimation task caused by the noisy ocean environment. This thesis envisages the implementation of a prototype automated system for underwater target localization, tracking and classification using passive listening buoy systems and target identification techniques. An autonomous three buoy system has been developed and field trials have been conducted successfully. Inaccuracies in the localization results, due to changes in the environmental parameters, measurement errors and theoretical approximations are refined using the Kalman filter approach. Simulation studies have been conducted for the tracking of targets with different scenarios even under maneuvering situations. This system can as well be used for classifying the unknown targets by extracting the features of the noise emanations from the targets.
Description:
Department of Electronics, Cochin University of Science and Technology.
Ganapathy, Rajendran; Dr.Kuriakose, A P(Cochin University of Science and Technology, August 21, 1995)
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Abstract:
The thesis consists of seven chapters. The first
chapter is a general introduction on rice by-products,
their composition and utilization at present. The
different milling processes adopted in paddy and the major
by-products obtained from these processes viz. rice husk,
rice bran, rice bran oil and rice husk ash are described.
The physical properties and chemical composition of the
rice husk and its general uses are given in detail. The
chemical composition of the rice bran and its separation
from paddy is also included. The details of solvent
extraction process used for obtaining rice bran oil and
also its chemical constitution is discussed in this
chapter. Also described is the preparation and the
different uses of rice husk ash. A literature survey is
also done on the utilization of rice by-products in rubber
and plastics as on today. The scope and objectives of the
present study is also included at the end of this chapter.
Description:
Department of
Polymer Science and Rubber Technology, Cochin University of
Science and Technology
Sreeraj, M; Dr.Sumam Mary,Idicula(Cochin University Of Science And Technology, July 30, 2012)
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Abstract:
Handwriting is an acquired tool used for communication of one's
observations or feelings. Factors that inuence a person's handwriting not
only dependent on the individual's bio-mechanical constraints, handwriting
education received, writing instrument, type of paper, background, but
also factors like stress, motivation and the purpose of the handwriting.
Despite the high variation in a person's handwriting, recent results from
different writer identification studies have shown that it possesses sufficient
individual traits to be used as an identification method.
Handwriting as a behavioral biometric has had the interest of researchers
for a long time. But recently it has been enjoying new interest due to an
increased need and effort to deal with problems ranging from white-collar
crime to terrorist threats. The identification of the writer based on a piece
of handwriting is a challenging task for pattern recognition. The main
objective of this thesis is to develop a text independent writer identification
system for Malayalam Handwriting. The study also extends to developing a
framework for online character recognition of Grantha script and Malayalam
characters
Description:
Department of Computer Science, Cochin University of Science and
Technology