Meera, Venugopal; Dr.Saramma, A V(Cochin University Of Science And Technology, August 9, 2004)
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Abstract:
Microorganisms distributed in the marine and brackish environments
play an important role in the decomposition of organic matter and
mineralisation in the system (Seshadri and lgnacimuthu, 2002). Estuary is
one of the most productive ecosystems, at the same time one among the
least explored ecosystems on earth, which has immense potential as a
source of potent microorganisms that produce valuable compounds
particularly, enzymes such as proteases. In this scenario, it is very
appropriate to embark on finding novel alkaline protease producers from the
estuarine system. The area where the present investigation was carried out
is a part of the extensive estuarine system of South India viz. Cochin Estuary.
There is meagre knowledge regarding the microbial composition, particularly
the protease producers of Cochin Estuary. Hence, the present study has
been undertaken with the objective of finding novel alkaline protease
producing bacteria from Cochin Estuary
Description:
Department of Marine Biology, Microbiology and
Biochemistry, Cochin University of science and Technology
Bejoy, Thomas; Dr.Sugunan, S(Cochin University Of Science And Technology, September 22, 2004)
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Abstract:
The objective of the present work is to improve the textural and structural
properties of zeolite-Y through ion exchange with rare earth metals. We meant to
obtain a comparative evaluation of the physicochemical properties and catalytic
activity of rare earth modified H-Y, Na-Y, K-Y, and Mg-Y zeolites. Friedel-Crafts
alkylations of benzene with higher 1- olefins such as 1-octene, 1-decene, and 1dodecene
for the synthesis of linear alkylbenzene (LAB) have been selected for the
present study. An attempt has also been directed towards the correlation of the
enhancement in 2-phenylalkane formation to the improvement in the textural and
structural properties upon rare earth modification for the zeolite-Y. The present
method for LAB synthesis stands as an effective Green alternative for the existing
hydrofluoric acid technology
Description:
Department of Applied Chemistry
Cochin University of Science and Technology
Sugunan, Sankaran; Binitha, N N(React Kinet.Catal.Lett.& Akademiai Kiado, March 27, 2008)
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Abstract:
Linear alkylbenzene sulfonic acid, the largest-volume synthetic surfactant, in addition to its excellent performance , is important due to its biodegradable environmental friendliness, as it has a straight chain and is prepared by the sulphonation of linear alkylbenzenes (LAB). To ensure environmental protection, the commercial benzene alkylation catalysts HF or AICI3 are replaced and we have developed a clean LAB production process using a pillared clay catalyst capable of not only replacing the conventional homogeneous catalyst, but also having high selectivity for the best biodegradable 2-phenyl LAB isomer .Pillared clay catalysts having high Bronsted acidity show efficient conversion in gas phase alkylation of benzene with 1-octene with a good 2-phenyl octane selectivity.
Jyothi, T M; Rao, B S; Sugunan, S; Sreekumar, K(Indian Journal of Chemistry, December , 1999)
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Abstract:
Alkylation of phenol with methanol has been carried out over
Sn-La and Sn-Sm mixed oxides of varying compositions at 623 K
in a vapour phase flow reactor. It is found that the product
selectivity is greatly influenced by the acid-base properties of the
catalysts. Ortho-cresol formation is favoured over catalysts with
weak acid sites whereas formation of 2,6-xylenol occurs in the
presence of stronger acid sites. The cyclohexanol decomposition
reaction and titrimetric method using Hammett indicators have
been employed to elucidate the acid-base properties of the
catalysts.
Description:
Indian Journal of Chemistry
Vol. 38A, December 1999, pp. 1253-1255
Almost self-centered graphs were recently introduced as the graphs
with exactly two non-central vertices. In this paper we characterize almost selfcentered
graphs among median graphs and among chordal graphs. In the first case
P4 and the graphs obtained from hypercubes by attaching to them a single leaf are
the only such graphs. Among chordal graph the variety of almost self-centered
graph is much richer, despite the fact that their diameter is at most 3. We also
discuss almost self-centered graphs among partial cubes and among k-chordal
graphs, classes of graphs that generalize median and chordal graphs, respectively.
Characterizations of almost self-centered graphs among these two classes seem
elusive
Description:
TAIWANESE JOURNAL OF MATHEMATICS
Vol. 16, No. 5, pp. 1911-1922, October 2012
Pius S,Padayatti; Paulose,C S(Department of Biotechnolgy, April 2, 1999)
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Abstract:
The brain stems (13S) of streptozotocin (STZ)-diabetic rats were studied lo see the changes in
neurotransmitter content and their receptor regulation. The norepinephrine (NE) content
determined in the diabetic brain stems did ^ control. an E showed la
while
PI turnover
hri
content increased significantly compared N^r eNveFa o the recep
significant increase. The alpha2 adrenergic receptor
IneP utisoulinntreat d ratsetheNE contentt dec^ sled
was significantly reduced during diabetes. in
versedcto reanorm
sed
ulcrea e tK
reatment
the
state.
while EPI content remained increased as in die diabetic
B,, for a]pha2 adrenergic receptors slw^nificantly while
Unlabelled clonidine inhibited [31-I]NE binding in BS of control, diabetic and insulin treated
ulations bindi
diabetic rats showed that alpha2 adrenergicre^ punks cojnidiabetic animal the ligand bound
sites with Hill slopes significantly away from unity.
weaker to the low affinity site than in controls. Insulin treatment reversed[ this allumbmn to
control levels. The displacement analysis using (-)-epinephrine age in
control and diabetic animals revealed two populations of receptor affinidtyo=tat ss. In control
animals, when GTP analogue added with epinephrine, the curve nagnlde caofnfitnroit yS
model; but in the diabetic BS this effect `not
aobserved. In
bintact
oth the diabetic
data thus showlthat
the effects of monovalent cations on affinity
alphaz adrenergic receptors have a reduced affinity v
due
in stem ialtered Itscppeomson(5-
regulation. The serotonin (5-HT) coat
hydroxy) tryptophan (5-HTP) showed an increase and its breakdown metabolite (5-hydroxy)
indoleacetic acid (5-I{IAA) showed a significant decrease. This showed that in serotonergic
which l
nerves there is a disturbance in both synthetic and breankduomwnbers pretma'med ana
increased 5-HT. The high affinity serotonin receptor um ese serotonerg
decrease in the receptor affinity. The insulin ^treatmentsturtiy showsha decreased serotonergic
receptor kinetic parameters to control level.
receptor function. These changes in adrenergic and serotonergic receptor function were
suggested to be important in insulin function during STZ diabetes.
Viswanathan,M; Paulose,C S; Lal,K J; Sharma,S K; Dakshinamurti,K(Department of Biotechnology, November 27, 1989)
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Abstract:
Moderate pyridoxine deficiency in adult male Sprague-Dawley rats results in significant hypertension,
associated with a general sympathetic stimulation , including an increase in the turnover of norepinephrine
in the heart. Treatment of these rats with pyridoxine reversed blood pressure to normal within 24 h. Treatment
of pyridoxine-deficient rats with clonidine or x-methyl dihydroxyphenylalanine (x-methyl DOPA)
also reduced the blood pressure of these animals to normal . There was also a significant increase in the
Bma, of high and low affinity [3H]p-amino-clonidine binding to crude synaptosomal membrane preparations
of the brain stem of deficient rats indicating chronic underexposure of)(, adrenoreceptors to endogenous
norepinephrin.
Renuka, T R; Ani Das, V; Paulose,C S(Department of Biotechnology, March 2, 2004)
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Abstract:
Muscarinic M1 and M3 receptor changes in the brain stem during pancreatic regeneration were investigated.
Brain stem acetylcholine esterase activity decreased at the time of regeneration . Sympathetic activity also
decreased as indicated by the norepinephrine (NE) and epinephrine (EPI) content of adrenals and also in the
plasma. Muscarinic Ml and M3 receptors showed reciprocal changes in the brain stem during regeneration.
Muscairnic M1 receptor number decreased at time of regeneration without any change in the affinity. High affinity
M3 receptors showed an increase in the number. The affinity did not show any change . The number of low affinity
receptors decreased with decreased Kd at 72 hours after partial pancreatectomy. The Kd reversed to control value
with a reversal of the number of receptors to near control value . Gene expression studies also showed a similar
change in the mRNA level of Ml and M3 receptors . These alterations in the muscarinic receptors regulate
sympathetic activity and maintain glucose level during pancreatic regeneration. Central muscarinic M1 and M3
receptor subtypes functional balance is suggested to regulate sympathetic and parasympathetic activity, which in
turn control the islet cell proliferation and glucose homeostasis.
Surekha, Mariam Varghese; Dr.Poulose Jacob, K(Cochin University of Science & Technology, March , 2008)
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Abstract:
Modern computer systems are plagued with stability and security
problems: applications lose data, web servers are hacked, and systems crash under
heavy load. Many of these problems or anomalies arise from rare program
behavior caused by attacks or errors. A substantial percentage of the web-based
attacks are due to buffer overflows. Many methods have been devised to detect
and prevent anomalous situations that arise from buffer overflows. The current
state-of-art of anomaly detection systems is relatively primitive and mainly
depend on static code checking to take care of buffer overflow attacks. For
protection, Stack Guards and I-leap Guards are also used in wide varieties.This dissertation proposes an anomaly detection system, based on
frequencies of system calls in the system call trace. System call traces represented
as frequency sequences are profiled using sequence sets. A sequence set is
identified by the starting sequence and frequencies of specific system calls. The
deviations of the current input sequence from the corresponding normal profile in
the frequency pattern of system calls is computed and expressed as an anomaly
score. A simple Bayesian model is used for an accurate detection.Experimental results are reported which show that frequency of system
calls represented using sequence sets, captures the normal behavior of programs
under normal conditions of usage. This captured behavior allows the system to detect anomalies with a low rate of false positives. Data are presented which show
that Bayesian Network on frequency variations responds effectively to induced
buffer overflows. It can also help administrators to detect deviations in program
flow introduced due to errors.
Description:
Department of Computer
Science, Cochin University of Science and Technology.
Mary, Kurien; Dr.Kuriakose, A P(Cochin University of Science And Technology, September 7, 2002)
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Abstract:
Earlier studies5773 in our laboratory showed that when a nucleophile
is used along with disulphide or sulphenamide accelerators the
vulcanization is accelerated greatly and the reaction mechanism is generally
nucleophilic in nature. However it was observed that it also changes with
the systems under review. The present study, deals with the use of
unsubstituted amidino thiourea i.e. aminoimino methyl thiourea(AMT) V in
the vulcanization studies of different elastorners and their blends. One of the
aims of this study was to get further proof with regard to the
theory of nucleophilic reaction mechanism in such binary systems.Mixes containing thiourea are used as controls. AMT is more nucleophilic
than TU and this is clear from the fact that the fonner can condense with
isothiocynate even in the absence of alkali while TU cannot". Also the
guanidinyl group in AMT can facilitate the polarization of the C=S bond
favouring a nucleophilic reaction
Description:
Department Of Polymer Science And Rubber Technology
Cochin University Of Science And Technology
Saji, K J; Dr.Jayaraj, M K(Cochin University of Science & Technology, October , 2008)
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Abstract:
This work
mainly concentrate to understand the optical and electrical properties of
amorphous zinc tin oxide and amorphous zinc indium tin oxide thin films
for TFT applications. Amorphous materials are promising in achieving
better device performance on temperature sensitive substrates compared
to polycrystalline materials. Most of these amorphous oxides are multicomponent
and as such there exists the need for an optimized chemical
composition. For this we have to make individual targets with required
chemical composition to use it in conventional thin film deposition techniques
like PLD and sputtering. Instead, if we use separate targets for
each of the cationic element and if separately control the power during the
simultaneous sputtering process, then we can change the chemical composition
by simply adjusting the sputtering power. This is what is done in co-sputtering technique. Eventhough there had some reports about thin
film deposition using this technique, there was no reports about the use
of this technique in TFT fabrication until very recent time. Hence in this
work, co-sputtering has performed as a major technique for thin film deposition
and TFT fabrication. PLD were also performed as it is a relatively
new technique and allows the use high oxygen pressure during deposition.
This helps to control the carrier density in the channel and also favours the
smooth film surface. Both these properties are crucial in TFT.Zinc tin oxide material is interesting in the sense that it does not contain
costly indium. Eventhough some works were already reported in ZTO based
TFTs, there was no systematic study about ZTO thin film's various optoelectronic
properties from a TFT manufacturing perspective. Attempts
have made to analyse the ZTO films prepared by PLD and co-sputtering.
As more type of cations present in the film, chances are high to form an
amorphous phase. Zinc indium tin oxide is studied as a multicomponent
oxide material suitable for TFT fabrication.
Description:
Department of Physics,
Cochin University of Science and Technology
Bindu, K; Dr.Vijayakumar, K P(Cochin University of Science & Technology, May , 2002)
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Abstract:
In the present work, we describe our efforts to develop device quality
CuInSe2, films through low cost, simple and eco-friendly hybrid techniques. The
most important point to be highlighted here is that the method fully avoids the use
of poisonous gases such as H2Se/Se vapour. Instead, selenisation is achieved
through solid state reaction between amorphous selenium and polycrystalline
metal layers resulting in both binary and ternary selenides. Thin films of
amorphous selenium (a-Se) used for this is deposited using Chemical Bath
Deposition (CBD). CulnSe2 films are prepared through the selenisation process.
Another PV material, indium selenide (In2Se3) thin films are also prepared using
this process.
Description:
Department of Physics, Cochin University of
Science and Technology
Harikrishnan, K P; Nandakumaran, V M(Elsevier, December 25, 1989)
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Abstract:
This is a sequel to our earlier work on the modulated logistic map. Here, we first show that the map comes under the universality class of Feigenbaum. We then give evidence for the fact that our model can generate strange attractors in the unit square for an uncountable number of parameter values in the range μ∞<μ<1. Numerical plots of the attractor for several values of μ are given and the self-similar structure is explicity shown in one case. The fractal and information dimensions of the attractors for many values of μ are shown to be greater than one and the variation in their structure is analysed using the two Lyapunov exponents of the system. Our results suggest that the map can be considered as an analogue of the logistic map in two dimensions and may be useful in describing certain higher dimensional chaotic phenomena.
Manju,Paulson; Sona,Kundukulam O; Aanandan,C K; Mohanan, P(Microwave and Optical Technology Letters, January 20, 2002)
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Abstract:
A dual-port dual-polarized compact microstrip antenna
for avoiding cross coupling between the two frequency bands is proposed
and analyzed. This antenna offers channel isolation better than 25 dB,
and is more compact compared to a conventional rectangular patch.
Analytical equations for calculating the resonant frequencies at both
ports are also presented. The theoretical calculations are verified using
experimental results