Aneeshkumar, B; Pramod, Gopinath; Jayan, Thomas; Vallabhan, C P G; Nampoori, V P N; Radhakrishnan, P(Elsevier, June , 2004)
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Abstract:
The nanosecond optical limiting characteristics of sandwich-type neodymium diphthalocyanine in a co-polymer matrix of polymethyl methacrylate (PMMA) and methyl-2-cyanoacrylate have been studied for the first time. The measurements were performed using 9 ns laser pulses generated from a frequency-doubled Nd:YAG laser at 532 nm wavelength. The optical limiting performance of neodymium diphthalocyanine in co-polymer host was studied at different linear transmission. Laser damage threshold was also measured for the doped and undoped co-polymer samples. The optical limiting response is attributed to reverse saturable absorption which is due to excited-state absorption.
Aswathy, K V; Dr. Rani, Joseph(Cochin University of Science & Technology, September , 2007)
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Abstract:
Various synthesis routes have been developed in recent years for the
preparation of nanoparticles. One of those methods is polymer induced
crystallization. The first objective of the present work was to prepare nano ZnO
powder by polymer induced crystallization in chitosan solution and to
characterize the material using different techniques like TEM, SEM, XRD,
FTLR, UV spectroscopy, TGA, DSC etc.The second object of the study is to prepare composites using nano ZnO. It
has been undertaken to explore the potential of nano ZnO as reinforcement in
engineering as well as commodity thermoplastics to widen their application
spectra. We selected three engineering thermoplastics like [poly ethylene
terephthalate, polyamide 6, and polycarbonate] and three commodity plastics
like [polypropylene, high density polyethylene, and polystyrene] for the study.
To date one of the few disadvantages associated with nanoparticle incorporation
has concerned toughness and impact performance. Modification of polymers
could reduce impact performance. The present study also focused on whether
nano ZnO can act as a modifier for thennoplastics, without sacrificing their
impact strength.
Description:
Department of Polymer Science and Rubber Technology,
Cochin University of Science and Technology
Mohammed Yusuff, K K; Leeju,P; Arun,V; Manju,Sebastian; Varsha,Gopalakrishnan; Digna,Varghese(Crystallography Journals,Acta Crystallographica Section E ,Structure Reports, July 15, 2009)
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Abstract:
In the title molecule, C16H11N5, the mean planes of the
quinoxaline and indazole fragments form a dihedral angle of
10.62 (5). In the crystal, weak intermolecular N—H..........N
hydrogen bonds link the molecules into zigzag chains
extending in the [001] direction. The crystal packing also
exhibits pye interactions [centroid–centroid distances of
3.7080 (2) and 3.8220 (5) A ˚ ], which form stacks of the
molecules parallel to the a axis
Dakshinamurti,K; Paulose,C S; Siow,Y L(Department of Biotechnology, 1985)
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Abstract:
Pyridoxal 5'-phosphate (PLP) is the major coenzymatic
form of pyridoxine. There are over one hundred known pyridoxal
5'-phosphate-dependent reactions, most of which are
involved in the metabolism of various amino acids . Pyridoxamine
5'-phosphate can function in aminotransf erase reactions
by the cyclic regeneration of the two active phosphate
forms. Pyridoxal 5'-phosphate-dependent reactions studied
in the nervous system are involved in the catabolism of various
amino acids. The putative neurotransmitters , dopamine,
norepinephrine , serotonin , histamine , aminobutyric acid
and taurine , as well as the sphingoiipids and poly amines are
synthesized by PLP-dependent enzymes. Of these enzymes,
three ( glutamic acid decarboxylase , 5-hydroxytryptophan decarboxylase
and crnithine decarboxylase) seem to have crucial
roles (Fig. '). The clinical effects of pyridoxine deficiency
can be explained on the basis of the known decreases
in the activities of these enzymes
Dakshinamurti,K; Paulose,C S; Viswanathan,M; Siow,Y L(Department of Biotechnology, 1988)
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Abstract:
Veuruenducrim lri v j p .rim,
deficienc:v. NEUROSCI BIOBEHAV REV 12(3/4) 189-193. 1988.- Dihydroxyphenylalanine decarboxvlase and
5-hydroxytryptophan decarboxvlase respectively have high and low affinities for pyridoxal phosphate. In the pyridoxinedeficient
animal. hypothalamic serotonin content is significantly reduced without any change in catecholamine levels.
Hypothalamic neurotransmitters affect the hvpothalamo-pituitary-end organ axes. Specifically, the decrease in hypothalamic
serotonin in the pyridoxine-deficient rat results in tertiary hypothyroidism. In addition. pineal function is affected in
deficient animals due to decreased synthesis of melatonin.
Paulose,C S; Amee,Krishnakumar; Anu,Joseph(Department of Biotechnology, 2007)
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Abstract:
Neuroscience is the study of'tbe ne rvous system , including the i - ; . in, spinal
cord and peripheral nerves . Neurons are the basic cells of the brain and
nervous system which exerts its functional role through various
neurotransmitters and receptor systems . The activity of a nen ren depends
on the balance between the number of excitatory and inhibito r y processes
affecting it, both processes occurring individually and sin ,tlte-' ,ieously. The
functional bal,ince of different neurotransmitters such as Acct >>lcholine
(Ach), Dopamine (DA), Serotonin (5-1-17), Nor epinepbri,te (N.1 j,
Epinephrine (LPI), Glutamate and Gamma amino butyric acid (GA BA)
regulates the growth , division and other vital functions ofa normal cell /
organisin (Sudha, 1 998). The micro-environ ; nertt of the cell is controlled
/ the macro-environment that surrounds the individual. Any change in
the cell environment causes imbalance in cell homeostasis and f,ntction.
Pollution is a significant cause of imbalance caused iii the inacYcenvironment.
Interaction with polluted environments can have an adverse
impact on the health of humans. The alarming rise in enviromilmieil
cont.iniin :rtion has been linked to rises in levels of pesticides, ndltstr al
effluents, domestic Waste, car exhausts and other anthropogenic activities.
Persistent exposures to contaminant cause a negative imp,-, on brain
health and development . Pollution also causes a change in the
neurotransmitters and their receptor function leading to earl.;' recurrence
of neurodcge,terative disorders such as flypoxia , Alzbeimers's and
Huntington 's disease early in life.
Paulose,C S; Amee,Krishnakumar; Anu,Joseph(Department of Biotechnology, October 25, 2006)
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Abstract:
The recent developments in neurobiology have rendered new prominence
and potential to study about the structure and function of brain and related disorders.
Human behaviour is the net result of neural control of the communication between
brain cells. Neurotransmitters are chemicals that are used to relay, amplify and
modulate electrical signals between neurons and/or another cell. It mediates rapid
intercellular communication through the nervous system by interacting with cell
surface receptors. These receptors often trigger second messenger signaling pathways
that regulate the activity of ion channels. The functional balance of different
neurotransmitters such as Acetylcholine (Ach), Dopamine (DA), Serotonin (5-HT),
Norepinephrine (NE), Epinephrine (EPI), Glutamate and Gamma amino butyric acid
(GABA) regulates the growth, division and other vital functions of a normal cell /
organism (Sudha, 1998). Any change in neurotransmitters' functional balance will
result in the failure of cell function and may lead to the occurrence of diseases.
Abnormalities in the production or functioning of neurotransmitters have been
implicated in a number of neurological disorders like Schizophrenia, Alzheimer's,
Epilepsy, Depression and Parkinson's disease. Changes in central and peripheral
neuronal signaling system is also noted in diabetes, cancer, cell proliferation,
alcoholism and aging. Elucidation of neurotransmitters receptor interaction pathways
and gene expression regulation by second messengers and transcriptional factors
in health and disease conditions can lead to new small molecules for development
of therapeutic agents to improve neurological disease conditions. Increased
awareness of the global effects of neurological disorders should help health care
planners and the neurological community set appropriate priorities in research,
prevention, and management of these diseases.
Supriyo,Dey; Aanandan,C K; Mohanan,P; K G Nair(Microwave and Optical Technology Letters, September , 1994)
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Abstract:
A simple technique to improve the impedance bandwidth of a circular
microstrip patch antenna using two sectorial slots is proposed. Using this
design more than 5% impedance bandwidth is obtained. The added
advantage of this new antenna is that it can be fed by a 50- microstrip line
Aanandan,C K; Mohanan,P; Supriyo,Dey; K G Nair(Department of Electronics, 1994)
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Abstract:
A simple technique to improve the impedance bandwidth of a circular
microstrip patch antenna using two sectorial slots is proposed. Using this
design more than 5% impedance bandwidth is obtained. The added
advantage of this new antenna is that it can be fed by a 50 microstrip
line.
K G Nair; Aanandan,C K; Mohanan,P; Supriyo,Dey(Department of Electronics, 1994)
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Abstract:
A simple technique to improve the impedance bandwidth of a circular
microstrip patch antenna using two sectorial slots is proposed. Using this
design more than 5% impedance bandwidth is obtained. The added
advantage of this new antenna is that it can be fed by a 50microstrip
line
Mohanan,P; K G Nair; Aanandan,C K; Supriyo,Dey(Department of Electronics, 1994)
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Abstract:
A simple technique to improve the impedance bandwidth of a circular
microstrip patch antenna using two sectorial slots is proposed. Using this
design more than 5% impedance bandwidth is obtained. The added
advantage of this new antenna is that it can be fed by a 50 microstrip
line
Supriyo,Dey; Aanandan,C K; Mohanan,P; K G Nair(Department of Electronics, 1994)
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Abstract:
A new modFed circularpatch antenna resonating at much lower
frequency compared to ordinary circular patch antenna having the same
radius is presented in this paper. me antenna also exhibits wide variation
in input impedance along the circumference of and hence can be matched
with microstrip feedline of any line impedance.
Manju,Paulson; Sona,Kundukulam O; Aanandan,C K; Mohanan,P(Microwave and Optical Technology Letters, June 5, 2001)
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Abstract:
A new compact dual-band, dual-polarized microstrip antenna
is presented. 7'iris antenna resonates at two frequencies with
different polarizations: a linearly polarized one for terrestrial
communication, and a circularly polarized one for satellite mobile
communication. This antenna also provides an area reduction of 70%
compared to a standard rectangular patch antenna
George,J; Deepukumar,M; Aanandan,C K; Mohanan,P; K G Nair(Department of Electronics, March , 1996)
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Abstract:
A new microstrip antenna geometry with considerable reduction
in size, with similar radiation characteristics to those of an
equivalent rectangular patch antenna is proposed. A relationship
has been suggested for fmding out the resonant frequency of the
new geometry, and its validity has been established by the
experimental results. Without increasing the aperture area, this
geometry also offers a facility for considerably reducing the
resonant frequency compared to conventional patches.
Sebastian, Mathew; Joe, Jacob; Joseph, V P; Bijukumar, S; Raveendranath, U; Mathew, K T(John Wiley & Sons, March 5, 1999)
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Abstract:
This paper presents the design of a new type of corner reflector (CR) antenna and the experimental investigation of its radiation characteristics. The design involves the addition of planar parallel periodic strips to the two sides of a CR antenna. The position, angular orientation, and number of strips have a notable effect on the H-plane radiation characteristics of the antenna. Certain configurations of the new antenna are capable of producing very sharp axial beams with gain on the order of 5 dB over the square corner reflector antenna. A configuration that can provide symmetric twin beams with enhanced gain and reduced half-power beam width (HPBW) is also presented.