Shaji,S; Abdul Rasheed, T M(Cochin University of Science and Technology, April , 2003)
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Abstract:
The present work is mainly concentrated on setting up a NIR tunable diode laser absorption (TDLA) spectrometer for high-resolution molecular spectroscopic studies. For successfully recording the high-resolution tunable diode laser spectrum, various experimental considerations are to be taken into account like the setup should be free from mechanical vibrations, sample should be kept at a low pressure, laser should be in a single mode operation etc. The present experimental set up considers all these factors. It is to be mentioned here that the setting up of a high resolution NIR TDLA spectrometer is a novel experiment requiring much effort and patience. The analysis of near infrared (NIR) vibrational overtone spectra of some substituted benzene compounds using local mode model forms another part of the present work. An attempt is made to record the pulsed laser induced fluorescence/Raman spectra of some organic compounds. A Q-switched Nd:YAG laser is used as the excitation source. A TRIAX monochromator and CCD detector is used for the spectral recording. The observed fluorescence emission for carbon disulphide is centered at 680 nm; this is assigned as due to the n, p* transition. Aniline also shows a broad fluorescence emission centered at 725 nm, which is due to the p,p* transition. The pulsed laser Raman spectra of some organic compounds are also recorded using the same experimental setup. The calibration of the set up is done using the laser Raman spectra of carbon tetrachloride and carbon disulphide. The observed laser Raman spectra for aniline, o-chloroaniline and m-chlorotoluene show peaks characteristics of the aromatic ring in common and the characteristics peaks due to the substitutuent groups. Some new peaks corresponding to low-lying vibrations of these molecules are also assigned
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
Godfrey,Louis; Jacob, Philip(Department of Physics, 1994)
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Abstract:
The thesis investigated the elastic properties and phase transitions in selected mixed sulphate crystals – Lithium Hydrazinium Sulphate [LiN2H2SO4], Lithium Ammonium Sulphate [LiNH4SO4] and Lithium Potassium Sulphate [LiKSO4] – using ultrasonic technique. The pulse echo overlap technique has been used for measuring ultrasonic velocity and its dependence on temperature along different directions with waves of longitudinal and transverse polarizations. Two major numerical techniques and the corresponding computer programs developed as part of present work are presented in this thesis. All the 9 elastic constants of LHS are determined accurately from ultrasonic measurements and applying misorientation correction refines the constants. Ultrasonic measurements are performed in LAS to determine the elastic constants and to study the low temperature phase transitions. Temperature variation studies of elastic constant of LAS are performed for 6 different modes of propagation for heating and cooling at low temperatures. All the 5 independent elastic constants of LPS is determined using ultrasonic measurements. It is concluded that LPS crystal does not undergo a phase transition near this temperature. A comparison of the three crystals studied shows that LPS has maximum number of phase transitions and LHS has the least number. It is interesting to note that LPS has the simplest formula unit among the three. There is considerable scope for the future work on these crystals and others belonging to the sulphate family.
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.
Nify, Benny; Dr.Sujatha, C H(Cochin University of Science and Technology, June , 2009)
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Abstract:
The thesis deals with a benchmark study of dissolved and sedimentary sulphur
compounds which play prominent roles in the prevailing redox conditions in the
selected sites of Cochin estuarine system. Sulphur and its analogues play prominent
roles in estuarine biochemical processes. A complete knowledge on the sulphur
involvement in these processes is restricted due to the lacking of data on the organic
sulphur compounds. Sulphate and sulphide in surface and bottom water and
Sulphate, acid volatile sulphide and total sulphur in sediments were studied and
correlated to know their interrelations in determining the redox condition of the
environment. It also characterises the sediments of the sites on the basis of total
organic carbon: total sulphur ratio. The study had attempted to decrease the
concentration levels of sulphur in the sedimentary environment by the application of
a remedial measure. Knowledge of sulphur uptake by plants from prior literatures
has prompted to use phytoremediation for decreasing the sulphur concentration.
Phytoremediation is an emerging technology that uses plants to clean up or remediate
contaminated soil, sludges, sediments, and ground water through contaminant
removal, degradation or containment. The plant selected was wheat grass since
earlier studies have shown that wheat grass is effective in remediating pollutants
particularly trace metals. So reduction in the concentration of selected trace metals
was also focussed.
Description:
Department of Chemical Oceanography, Cochin University of Science and Technology
Radhakrishnan, N; Dr.Meera Bai,M(Cochin University of Science and Technology, November 20, 2003)
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Abstract:
Studies in urban water supply system are few in the state of Kerala.
It is a little researched area. In the case of water pricing a number of studies are
available. In Kerala state, exception to Jacob John’s study on “Economics of
Public Water Supply System”, which is a case study of Trivandrum Water Supply
System in 1997, no exhaustive research work has so far come out in this field.
loreover no indepth research study has come up, so far, relating to household
ater demand analysis and the distribution system of urban piped water supply.
he proposed study is first of its kind, which focuses on the distributional and
Iailability problems of piped water supply in an urban centre in Kerala state.
Hence there is a felt need for enquiring into the sufficiency of
)table water supplied to people in urban areas and the efficiency maintained in
roviding the scarce resource and preventing its misuse by the consumers. It is in
llS backdrop that this study was undertaken and its empirical part was conducted
|Calicut city in the state of Kerala. Study is confined to the water supply system
ithe city of Calicut
Description:
Department of Applied Economics,
Cochin University of Science and Technology
Babu, K K; Dr. Beena, K S(Cochin University of Science and Technology, May , 2007)
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Abstract:
The increasing tempo of construction activity the world over creates heavy pressure
on existing land space. The quest for new and competent site often points to the needs
for improving existing sites, which are otherwise deemed unsuitable for adopting
conventional foundations. This is accomplished by ground improvement methods,
which are employed to improve the quality of soil incompetent in their natural state.
Among the construction activities, a well-connected road network is one of the basic
infrastructure requirements, which play a vital role for the fast and comfortable
movement of inter- regional traffic in countries like India.One of the innovative ground improvement techniques practised all over the world is
the use of geosynthetics, which include geotextiles, geomembranes, geogrids, etc .
They offer the advantages such as space saving, enviromnental sensitivity, material
availability, technical superiority, higher cost savings, less construction time, etc .
Because of its fundamental properties, such as tensile strength, filtering and water
permeability, a geotextile inserted between the base material and sub grade can
function as reinforcement, a filter medium, a separation layer and as a drainage
medium. Though polymeric geotextiles are used in abundant quantities, the use of
natural geotextiles (like coir, jute, etc.) has yet to get momentum. This is primarily
due to the lack of research work on natural geotextilcs for ground improvement,
particularly in the areas of un paved roads. Coir geotextiles are best suited for low cost
applications because of its availability at low prices compared to its synthetic
counterparts. The proper utilisation of coir geotextilcs in various applications demands large quantities of the product, which in turn can create a boom in the coir
industry. The present study aims at exploring the possibilities of utilising coir
geotextiles for unpaved roads and embankments.The properties of coir geotextiles used have been evaluated. The properties studied
include mass per unit area, puncture resistance, tensile strength, secant modulus, etc .
The interfacial friction between soils and three types of coir geotextiles used was also
evaluated. It was found that though the parameters evaluated for coir geotextiles have
low values compared to polymeric geotextiles, the former are sufficient for use in
unpaved roads and embankments. The frictional characteristics of coir geotextile - soil
interfaces are extremely good and satisfy the condition set by the International
Geosynthetic Society for varied applications.The performance of coir geotextiles reinforced subgrade was studied by conducting
California Bearing Ratio (CBR) tests. Studies were made with coir geotextiles placed
at different levels and also in multiple layers. The results have shown that the coir
geotextile enhances the subgrade strength. A regression analysis was perfonned and a
mathematical model was developed to predict the CBR of the coir geotextile
reinforced subgrade soil as a function of the soil properties, coir geotextile properties,
and placement depth of reinforcement.The effects of coir geotextiles on bearing capacity were studied by perfonning plate
load tests in a test tan1e This helped to understand the functioning of geotextile as
reinforcement in unpaved roads and embankments. The perfonnance of different
types of coir geotextiles with respect to the placement depth in dry and saturated
conditions was studied. The results revealed that the bearing capacity of coir-reinforced soil is increasing irrespective of the type of coir geotextiles and saturation
condition.The rut behaviour of unreinforced and coir reinforced unpaved road sections were
compared by conducting model static load tests in a test tank and also under repetitive
loads in a wheel track test facility. The results showed that coir geotextiles could
fulfill the functions as reinforcement and as a separator, both under static and
repetitive loads. The rut depth was very much reduced whik placing coir geotextiles
in between sub grade and sub base.In order to study the use of Coir geotextiles in improving the settlement
characteristics, two types of prefabricated COlf geotextile vertical drains were
developed and their time - settlement behaviour were studied. Three different
dispositions were tried. It was found that the coir geotextile drains were very effective
in reducing consolidation time due to radial drainage. The circular drains in triangular
disposition gave maximum beneficial effect.In long run, the degradation of coir geotextile is expected, which results in a soil -
fibre matrix. Hence, studies pertaining to strength and compressibility characteristics
of soil - coir fibre composites were conducted. Experiments were done using coir
fibres having different aspect ratios and in different proportions. The results revealed
that the strength of the soil was increased by 150% to 200% when mixed with 2% of
fibre having approximately 12mm length, at all compaction conditions. Also, the
coefficient of consolidation increased and compression index decreased with the
addition of coir fibre.Typical design charts were prepared for the design of coir geotextile reinforced
unpaved roads. Some illustrative examples are also given. The results demonstrated that a considerable saving in subase / base thickness can he achieved with the use of
eoir geotextiles, which in turn, would save large quantities of natural aggregates.
Description:
Division of Civil Engineering,
Cochin University of Science and Technology
Anil, Loveson; Rajathy, Sivalingam(Cochin University of Science And Technology, August , 2014)
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Abstract:
One of the objectives of the current investigation was to evaluate the effectiveness of Spirodela polyrhiza to remove heavy metals and other contaminants from the water samples collected from wetland sites of Eloor and Kannamaly under controlled conditions .The results obtained from the current study suggest that the test material S. polyrrhiza should be used in the biomonitoring and phytoremediation of municipal, agricultural and industrial effluents because of their simplicity, sensitivity and cost-effectiveness. The study throws light on the potential of this plant which can be used as an assessment tool in two diverse wetland in Ernakulum district. The results show the usefulness of combining physicochemical analysis with bioassays as such approach ensures better understanding of the toxicity of chemical pollutants and their influence on plant health. The results shows the suitability of Spirodela plant for surface water quality assessment as all selected parameters showed consistency with respect to water samples collected over a 3-monitoring periods. Similarly the relationship between the change in exposure period (2, 4 and 8 days) with the parameters were also studied in detail. Spirodela are consistent test material as they are homogeneous plant material; due to predominantly vegetative reproduction. New fronds are formed by clonal propagation thus, producing a population of genetically homogeneous plants. The result is small variability between treated individuals. It has been observed that phytoremediation of water samples collected from Eloor and Kannamaly using the floating plant system is a predominant method which is economic to construct, requires little maintenance and eco friendly.
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