Deepu, V; Rohith, K R; Manoj, J; Suma,M N; Vasudevan, K; Aanandan,C K; Mohanan, P(Electronics Letters, January 18, 2007)
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Abstract:
A compact dual-band uniplanar antenna for operation in the 2.4/5.2/5.8 GHz WLAN/HIPERLAN2 communication bands is presented. The dual-band antenna is obtained by modifying one of the lateral strips of a slot line, thereby producing two different current paths. The antenna occupies a very small area of 14.5times16.6 mm2 including the ground plane on a substrate having dielectric constant 4.4 and thickness 1.6 mm at 2.2 GHz. The antenna resonates with two bands from 2.2 to 2.52 GHz and from 5 to 10 GHz with good matching, good radiation characteristics and moderate gain
Binu, Paul; Mridula, S; Mohanan, P; Bijumon, P V; Sebastian,M T(Microwave and Optical Technology Letters, October 20, 2004)
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Abstract:
very-high-permittivity (e, = 100) multiband dielectrice>
e resonator antenna is presented. The compact antenna, excited by a
m:'crostrip line, resonates at two frequencies centered around the 1.9-
GHz and 2.4-GHz bands with identical polarization . The behavior of the
antenna at different positions along the feed line is studied and optimized.
Multiple resonances with the same polarization and broad radioticn
patterns suggest the suitability of the antenna for multiband wireless
application
Mohanan, P; Joseph,M; Paul,B; Raj,R K(Department of Electronics, November 11, 2004)
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Abstract:
A novel compact wideband antenna for wireless local area network
(WLAN) applications in the 2.4 GHz band is presented. The proposed
low profile antenna of dimensions 15 x 14.5 x 1.6 mm offers 18.6%
bandwidth and an average gain of -5 dBi. The antenna can be excited
directly using a 50 coaxial probe
A novel compact wideband antenna for wireless local area network
(WLAN) applications in the 2.4 GHz band are presented. The proposed
low profile antenna of dimensions 15 x 14.5 x 1.6 mm offers 18.6%
bandwidth and an average gain of~5 dBi. The antenna can be excited
directly using a 50 coaxial probe
Bright Singh, I S; Shibu, K Mani; Ranjit, Kanjur; Robert, Reed H(Elsevier, November 23, 2005)
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Abstract:
This study investigated the enhancement of solar disinfection using custom-made batch
reactors with reflective (foil-backed) or absorptive (black-backed) rear surfaces, under a
range of weather conditions in India. Plate counts of Escherichia coli ATCC11775 were made
under aerobic conditions and under conditions where reactive oxygen species (ROS) were
neutralised, i.e. in growth medium supplemented with 0.05% w/v sodium pyruvate plus
incubation under anaerobic conditions. While the addition of either an absorptive or a
reflective backing enhanced reactor performance under strong sunlight, the reflective
reactor was the only system to show consistent enhancement under low sunlight, where
the process was slowest. Counts performed under ROS-neutralised conditions were slightly
higher than those in air, indicating that a fraction of the cells become sub-lethally injured
during exposure to sunlight to the extent that they were unable to grow aerobically.
However, the influence of this phenomenon on the dynamics of inactivation was relatively
small
There is a growing commercial interest in the ¢sh,
Puntius ¢lamentosus, in the ornamental ¢sh trade in
India and elsewhere.The trade is, however, hampered
by severe mortalities during transport of the ¢sh owing
to insu⁄cient data available on the use of anaesthetics.
To resolve this problem, we evaluated the
e⁄cacy of two anaesthetics, MS-222 and benzocaine,
in sedating P. ¢lamentosus in simulated transportation
experiments and used stress response parameters
such as cortisol and blood glucose levels to
perform assessments. We observed that MS-222 at
40 mg L 1 and benzocaine at 20mg L 1 were su⁄-
cient to induce sedation for 48 h. Above these concentrations,
both the anaesthetics adversely a¡ected
the ¢sh and resulted inmortalities. Both anaesthetics
signi¢cantly lowered the blood cortisol and glucose
levels compared with the unsedated controls. Importantly,
the anaesthetics treatment signi¢cantly lowered
the post-transport mortality in the ¢sh.
The results of the study show that MS-222 and benzocaine
could be used as sedatives to alleviate transport-
related stress in P. ¢lamentosus to improve
their post-transport survival and hence reduce
economic loss.
Jinesh, Mathew; Mahesh, V V; Radhakrishnan, P(International Frequency Sensor Association, August , 2008)
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Abstract:
The design and fabrication of fiber based ammonia sensors employing Bromothymol blue
and Chitosan as sensing elements are presented in this paper. In the presence of ammonia gas the
absorption of Bromothymol blue changes while in the case of Chitosan the refractive index changes
which in turn modulates the intensity of light propagating through a fiber.
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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Abstract:
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
Description:
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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Abstract:
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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Abstract:
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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Abstract:
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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Abstract:
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