Sumam, Mary Idicula; Mohanty, U C; Litta, A J(November , 2011)
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Abstract:
Severe local storms, including tornadoes, damaging hail and wind gusts, frequently occur over the eastern and northeastern states of India during the pre-monsoon season (March-May). Forecasting thunderstorms is one of the most difficult tasks in weather prediction, due to their rather small spatial and temporal extension and the inherent non-linearity of their dynamics and physics. In this paper, sensitivity experiments are conducted with the WRF-NMM model to test the impact of convective parameterization schemes on simulating severe thunderstorms that occurred over Kolkata on 20 May 2006 and 21 May 2007 and validated the model results with observation. In addition, a simulation without convective parameterization scheme was performed for each case to determine if the model could simulate the convection explicitly. A statistical analysis based on mean absolute error, root mean square error and correlation coefficient is performed for comparisons between the simulated and observed data with different convective schemes. This study shows that the prediction of thunderstorm affected parameters is sensitive to convective schemes. The Grell-Devenyi cloud ensemble convective scheme is well simulated the thunderstorm activities in terms of time, intensity and the region of occurrence of the events as compared to other convective schemes and also explicit scheme
Description:
International Journal of Computer Applications (0975 – 8887)
Volume 33– No.6, November 2011
Kailasnath, M; John, P R; Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(Elsevier, 2008)
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Abstract:
This study was conducted to identify the concentration dependence of the operating wavelengths and the relative intensities in which a dye
mixture doped polymer optical fibre can operate. A comparative study of the radiative and Forster type energy transfer processes in Coumarin
540:Rhodamine 6G, Coumarin 540:Rhodamine B and Rhodamine 6G:Rhodamine B in methyl methacrylate (MMA) and poly(methyl methacrylate)
(PMMA) was done by fabricating a series of dye mixture doped polymer rods which have two emission peaks with varying relative intensities.
These rods can be used as preforms for the fabrication of polymer optical fibre amplifiers operating in the multi-wavelength regime. The 445 nm
line from an Nd:YAG pumped optical parametric oscillator (OPO) was used as the excitation source for the first two dye pairs and a frequency
doubled Nd:YAG laser emitting at 532 nm was used to excite the Rh 6G:Rh B pair. The fluorescence lifetimes of the donor molecule in pure
form as well as in the mixtures were experimentally measured in both monomer and polymer matrices by time-correlated single photon counting
technique. The energy transfer rate constants and transfer efficiencies were calculated and their dependence on the acceptor concentration was
analysed. It was found that radiative energy transfer mechanisms are more efficient in all the three dye pairs in liquid and solid matrices.
Jinesh, Mathew; Thomas, K J; Nampoori, V P N; Radhakrishnan, P(IFSA, 2007)
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A comparative study of two biopolymer based fiber optic humidity sensors is presented in this paper. Sensing elements Agarose and Chitosan swells in the presence of water vapour and undergoes changes in refractive index and modulates the intensity of light propagating through a fiber with Agarose or Chitosan as cladding.
Augustin, Antony; Dr. Babu, Philip(Cochin University of Science and Technology, December 8, 1994)
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Abstract:
A comparative study of Glycogen phosphorylase from selected Cephalopods is reported in this thesis. A detailed investigation of an important glycolytic enzyme, phosphorylase, from a selected species, is undertaken. Loligo vulgaris, commonly known as squid, is selected as the source for the study. Phosphorylase is the key enzyme in the mobilization of chemical energy from glycogen and its role in the regulation of carbohydrate metabolism is well established. Although a good deal of information is available about phosphorylase from terrestrial animals, not much is known about the enzyme from aquatic fauna. In order to bridge this gap and also to compare the results with the findings from other sources, phosphorylase a was isolated from this marine mollusc and its properties studied in detail in this study
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School of Marine Sciences, Cochin University of Science & Technology
Kannan, Balakrishnan; Harsha, K M; Facila Chinchu, O; Cini, Kurian(February 9, 2013)
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A primary medium for the human beings to communicate through language is Speech. Automatic Speech Recognition is wide spread today. Recognizing single digits is vital to a number of applications such as voice dialling of telephone numbers, automatic data entry, credit card entry, PIN (personal identification number) entry, entry of access codes for transactions, etc. In this paper we present a comparative study of SVM (Support Vector Machine) and HMM (Hidden Markov Model) to recognize and identify the digits used in Malayalam speech.
Bindhu, Jacob; Dr.Sugunan, S(Cochin University of Science & Technology, February , 1998)
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In this thesis an attempt has been made to compare the catalytic activity of
some medium and large pore zeolites in a few alkylation and acylation reactions. The
work reported in the present study is basically centered around the following zeolites
namely, ZSM-5, mordenite, zeolite Y and beta. The major reactions carried out were
benzoylation of o-xylene, propionylation of toluene and anisole and benzylation of 0xylene.The programme involves the synthesis, modifications and characterization of
the zeolite catalysts by various methods. The influence of various parameters such as
non-framework cations, Si/AI ratio of zeolites, temperature of the reaction, catalyst
concentration, molar ratio of the reactants and recycling of the catalysts were also
examined upon the conversion of reactants and the formation of the desired products
in the alkylation / acylation reactions.The general conclusions drawn by us from the results obtained are summarized
in the last chapter of the thesis. Zeolite beta offers interesting opportunities as a
potential catalyst in alkylation reactions and the area of catalysis by medium and large
pore zeolites is very fascinating and there is plenty of scope for further research in this
field. Moreover, zeolite based catalysts are effective in meeting current industrial
processing and more stringent environment pollution limits.
Description:
Department of Applied Chemistry, Cochin
University of Science and Technology
Bindhu, Jacob; Dr.Sugunan, S(Cochin University Of Science And Technology, February 13, 1998)
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Zeolites have established themselves as industrial catalysts for over two
decades for a variety of hydrocarbon processing reactions where acidity and shape
selectivity are important factors. As solid catalysts, zeolites may be advantageous and
superior compared to their homogenous counterparts due to their characteristic
properties. It is only in recent years that the utility of zeolites for organic synthesis is
recognized for producing specific organic intermediates and fine chemicals in high
selectivity.
In this thesis an attempt has been made to compare the catalytic activity of
some medium and large pore zeolites in a few alkylation and acylation reactions. The
work reported in the present study is basically centered around the following zeolites
namely, ZSM-5, mordenite, zeolite Y and beta. The major reactions carried out were
benzoylation of o-xylene, propionylation of toluene and anisole and benzylation of oxylene.
.
The programme involves the synthesis, modifications and characterization of
the zeolite catalysts by various methods. The influence of various parameters such as
non-framework cations, Si/Al ratio of zeolites, temperature of the reaction, catalyst
concentration, molar ratio of the reactants and recycling of the catalysts were also
examined upon the conversion of reactants and the formation of the desired products
in the alkylation/ acylation reactions.
The general conclusions drawn by us from the results obtained are summarized
in the last chapter of the thesis. Zeolite beta ofi'ers interesting opportunities as a
potential catalyst in alkylation reactions and the area of catalysis by medium and large
pore zeolites is very fascinating and there is plenty of scope for further research in this
field. Moreover, zeolite based catalysts are effective in meeting current industrial
processing and more stringent environment pollution limits.
Description:
Department of Applied Chemistry, Cochin
University of Science and Technology
Narayanan, K P; Baiju, Sasidharan; Aneesh, K N(IJIRSET, December , 2013)
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Welding of high strength and low weight materials like Aluminium Alloys without any defects by conventional
welding techniques is a major challenge in industries. Hence research on solid state welding techniques like Friction
stir welding and Friction welding techniques have got much importance in joining of Aluminium alloys. However
most of the industries are not changing conventional techniques as skilled workers are available on that area. Most
common conventional welding techniques used for joining of Aluminium alloys are Gas welding and Arc welding.
Friction welding is a solid-state welding process that generates heat through mechanical friction between a moving
and a stationary component with the addition of a lateral force called “upset” to plast ically displace and fuse the
materials. In this work, experimental study on tensile and micro structural characteristics of welded joints formed
from conventional welding techniques and Rotary friction welding(suitable for weld specimens with circular cross
section) has been carried out and the same were compared. The process parameters for arc welding used was 50-70
Amp reverse polarity DC and electrodes of 2.3mm diameter. In Gas welding, the parameters were oxy acetylene
neural flame at 3200°C and 3mm electrodes . In the case of friction welding an axial pressure loading of 3Mpa with
5 MPa as upsetting pressure and 500 rpm were used to obtain good welded joints. Tensile characteristic studies of
Arc welded joints and Gas welded joints showed 48% and 60 % variations respectively from the maximum load
bearing characteristics of parent metal. In the case of friction welded joint, the variation was found to 46%. Micro
structural evaluation of conventionally welded joints exhibited clear distinct zones of various weld regions. In the
case of friction welded joint micro structural photographs showed comparable features both in parent metal and
welded region. Thus the tensile characteristic study and microstructure evaluations proved that friction welded joints
are good in both aspects compared to conventionally welded joints.
Description:
International Journal of Innovative Research in Science, Engineering and Technology,Volume 2, Special Issue 1, December 2013
Devadasan,K; Dr.Gopakumar, K(Cochin University of Science and Technology, December , 1982)
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This thesis is an attempt to make a comparative study of the composition of the muscle proteins of some commercially important species of fishes and shell fishes of our coast and their changes during preservation and processing. As a part of this the distribution of the major protein nitrogen fractions in several species of fishes and shell fishes was studied in detail.
Anwarul Islam, MD; Dr.Ranganathan, N(Cochin University Of Science And Technology, November 5, 1988)
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For improving agricultural marketing, which has
been discussed in the previous chapter, the Government has
intervened in different ways. The direct regulatory role
through the regulation of markets and market practices is one
of the ways in which governmental intervention can improve
agricultural marketing. This study is an enquiry of the direct
regulatory role of the government through regulation of markets
and market practices. By restructuring the operational methods
and redesigning the existing physical markets, this system
gives direct benefit to the cultivating class and protects
them from the market manipulations of organised and powerful
private traders. If traders do not continue their trade for
the time being they will not be affected financially, because
they are resourceful or financially solvent. On the other
hand, Cultivators must sell their produce immediately after
harvesting for the lack of additional facilities or to satisfy
other needs for which finance is required. Another important
reason is that Cultivators/farmers are not organised and because of lack of their organisation, they sell their produces
individually. In this situation, a farmer is helpless when
astute traders indulge in manipulations at the time of purchase of the produces. So it is the government's obligation to protect the interest of the farmers. Protection of the farmer/cultivator is necessary not only from the point of social justice but also from that of economic growth. If the farmers are assured of a remunerative or incentive price for their produce, they will get the inspiration to produce more and through more production, economy will be developed and
the nation as a whole will be benefitted.
This study will examine the management system of the
markets through the direct regulatory role played by the
governments to control markets and market practices in West
Bengal and Bangladesh.
Description:
School Of Management Studies,
Cochin University Of Science And Technology
Poulose Jacob,K; Sonia, Sunny; David, Peter S(Cochin University of Science and Technology, 2013)
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Abstract:
Speech is a natural mode of communication for people and speech recognition is an intensive area of research due to its versatile applications. This paper presents a comparative study of various feature extraction methods based on wavelets for recognizing isolated spoken words. Isolated words from Malayalam, one of the four major Dravidian languages of southern India are chosen for recognition. This work includes two speech recognition methods. First one is a hybrid approach with Discrete Wavelet Transforms and Artificial Neural Networks and the second method uses a combination of Wavelet Packet Decomposition and Artificial Neural Networks. Features are extracted by using Discrete Wavelet Transforms (DWT) and Wavelet Packet Decomposition (WPD). Training, testing and pattern recognition are performed using Artificial Neural Networks (ANN). The proposed method is implemented for 50 speakers uttering 20 isolated words each. The experimental results obtained show the efficiency of these techniques in recognizing speech
Sreekumar, K; Thomas, Mathew; Mirajkar, S P; Sugunan, S; Rao, B S(Elsevier, 2000)
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Abstract:
The catalyst compositions of the Zn1−xCOxFe2O4 (x= 0, 0.2, 0.5, 0.8 and 1.0) spiel series possessing ‘x’ values, x less than or equal to 0.5, are
unique for selective N-monomethylation of aniline using methanol as the alkylating agent. Since dimethyl carbonate (DMC)
is another potential non-toxic alkylating agent, alkylation of aniline was investigated over various Zn–Co ferrites using DMC
as the alkylating agent. The merits and demerits of the two alkylating agents are compared. Catalytic activity followed a
similar trend with respect to the composition of the ferrospinel systems. DMC is active at comparatively low temperature,
where methanol shows only mild activity. However, on the selectivity basis, DMC as an alkylating agent could not compete
with methanol, since the former gave appreciable amounts of N,N-dimethylaniline (NNDMA) even at low temperature where
methanol gave nearly 99% N-methylaniline (NMA) selectivity. As in the case of methanol, DMC also did not give any
C-alkylated products.
Jyothi, T M; Sugunan, S; Rao, B S(Catalysis Letters, 2000)
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Abstract:
A comparative study on the anisole methylation with methanol over lanthanum-promoted Sn02 catalyst and its sulfate-doped analogue
is presented. A maximum 2.6-xylenol selectivity of 82% was achieved at 400 degreeC under optimized conditions at an anisole
conversion of 65% over lanthanum-promoted Sn02 catalyst. The sulfate modification resulted in the dealkylation of anisole to phenol
followed by several unselective side reactions due to the creation of strong acid sites. The activity of lanthanum-modified tin oxide
catalysts in the selective formation of 2.6-xylenol is ascribed to the presence of weak Lewis acid sites and comparatively stronger basic
sites.