Susha,D; Thrivikraman,T(Cochin University of Science and Technology, September , 2004)
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Abstract:
The topology as the product set with a base chosen as all products of open sets in the individual spaces. This topology is known as box topology. The main objective of this study is to extend the concept of box products to fuzzy box products and to obtain some results regarding them. Owing to the fact that box products have plenty of applications in uniform and covering properties, here made an attempt to explore some inter relations of fuzzy uniform properties and fuzzy covering properties in fuzzy box products. Even though the main focus is on fuzzy box products, some brief sketches regarding hereditarily fuzzy normal spaces and fuzzy nabla product is also provided.
The main results obtained include characterization of fuzzy Hausdroffness and fuzzy regularity of box products of fuzzy topological spaces. The investigation of the completeness of fuzzy uniformities in fuzzy box products proved that a fuzzy box product of spaces is fuzzy topologically complete if each co-ordinate space is fuzzy topologically complete. The thesis also prove that the fuzzy box product of a family of fuzzy α-paracompact spaces is fuzzy topologically complete. In Fuzzy box product of hereditarily fuzzy normal spaces, the main result obtained is that if a fuzzy box product of spaces is hereditarily fuzzy normal ,then every countable subset of it is fuzzy closed. It also deals with the notion of fuzzy nabla product of spaces which is a quotient of fuzzy box product. Here the study deals the relation connecting fuzzy box product and fuzzy nabla product
Jackson,James; Paulose,C S(Department of Biotechnology, May 1, 2000)
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Abstract:
5-HT2A receptor binding parameters were studied in the cerebral cortex and brain stem of
control, diabetic, insulin, insulin + tryptophan and tr3yptophan treated streptozotocin diabetic
rats. Scatchard analysis using selective antagonist, [-H](±)2,3-dimethoxyphenyl-l-[2-(4-piperidine)-
methanol] ([3H]MDL100907) in cerebral cortex of diabetic rats showed a significant
decrease in dissociation constant (Kd) without any change in maximal binding (Bm). Competition
binding studies in cerebral cortex using ketanserin against [3H]MDL100907 showed
the appearance of an additional site in the low affinity region during diabetes. In the brain
stem, Scatchard analysis showed a significant increase in Bmax and Kd. Displacement studies
showed a shift in the receptor affinity towards a low affinity state. All these altered parameters
in diabetes were reversed to control level by insulin, insulin + tryptophan and tryptophan
treatments. Tryptophan treatment is suggested to reverse the altered 5-HT2Abinding and
blood glucose level to control status by increasing the brain 5-HT content.
Biju,M P; Paulose,C S(Department of Biotechnology, September 27, 1997)
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Abstract:
Kinetic parameters of brain glutamate dehydrogenase (GDH) were compared in the brain
stem, cerebellum and cerebral cortex of three weeks and one year old streptozotocin (STZ)
induced four day diabetic rats with respective controls. A single intrafemoral dose of STZ
(60mg/Kg body weight) was administered to induce diabetes in both age groups. After four days
the blood glucose levels showed a significant increase in the diabetic animals of both age groups
compared with the respective controls. The increase in blood glucose was significant in one year
old compared to the three weeks old diabetic rats. The Vmm of the enzyme was decreased in all
the brain regions studied, of the three weeks old diabetic rats without any significant change in
the Km. In the adult the Vmax of GDH was increased in cerebellum and brain stem but was
unchanged in the cerebral cortex. The K. was unchanged in cerebellum and cerebral cortex but
was increased in the brain stem. These results suggest there may be an important regulatory role
of the glutamate pathway in brain neural network disturbances and neuronal degeneration in
diabetes as a function of age.
Raveendranath, U; Bijukumar, S; Mathew, K T(IEEE, December , 2000)
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Abstract:
A novel cavity perturbation technique using coaxial cavity resonators for the measurement of complex permittivity of liquids is presented. The method employs two types of resonators (Resonator I and Resonator II). Resonator I operates in the frequency range 600 MHz-7 GHz and resonator II operates in the frequency range 4 GHz-14 GHz. The introduction of the capillary tube filled with the sample liquid into the coaxial resonator causes shifts in the resonance frequency and loaded Q-factor of the resonator. The shifts in the resonance frequency and loaded Q-factor are used to determine the real and imaginary parts of the complex permittivity of the sample liquid, respectively. Using this technique, the dielectric parameters of water and nitrobenzene are measured. The results are compared with those obtained using other standard methods. The sources of errors are analyzed.
Mohanan,P; Bijumon,P V; Menon,S K; Suma,M N; Sebastain,M T(Department of Electronics, March 31, 2005)
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Abstract:
The impedance bandwidth of a high permittivity cylindrical dielectric
resonator antenna excited by a micro strip line was significantly
improved by modifying the feed geometry. The 10 dB return loss
bandwidth is enhanced from 12 to 26% without much affecting the
gain and other radiation properties of the antenna. Good agreement
has been observed between the predicted and measured results
The impedance bandwidth of a high permittivity cylindrical dielectric
resonator antenna excited by a micro strip line was significantly
improved by modifying the feed geometry. The 10 dB return loss
bandwidth is enhanced from 12 to 26% without much affecting the
gain and other radiation properties of the antenna. Good agreement
has been observed between the predicted and measured results
Deepukumar,M; George,J; Aanandan,C K; Mohanan,P; K G Nair(IEE Electronics letters,UK, June 19, 1996)
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Abstract:
A new dual port microstrip antenna geometry for dual frequency
operation is presented. The structure consists of the intersection
of two circles of the same radius with their centres displaced by a
small fraction of the wavelength . This antenna provides wide
impedance bandwidth and excellent isolation between its ports.
The gain of the antenna is comparable to that of a standard
circular microstrip antenna operating at the same resonant
frequency. A theoretical analysis for calculating the resonant
frequencies of the two ports is also presented
K G Nair; Aanandan,C K; Mohanan,P; Deepukumar,M; George,J(Department of Electronics, August 15, 1996)
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Abstract:
A new dual port microstrip antenna geometry for dual frequency
operation is presented. The structure consists of the intersection
of two circles of the same radius with their centres displaced by a
small fraction of the wavelength . This antenna provides wide
impedance bandwidth and excellent isolation between its ports.
The gain of the antenna is comparable to that of a standard
circular microstrip antenna operating at the same resonant
frequency. A theoretical analysis for calculating the resonant
frequencies of the two ports is also presented
Aanandan,C K; Mohanan,P; K G Nair; Deepukumar,M; George,J(Department of Electronics, August 15, 1996)
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Abstract:
A new dual port microstrip antenna geometry for dual frequency
operation is presented. The structure consists of the intersection
of two circles of the same radius with their centres displaced by a
small fraction of the wavelength . This antenna provides wide
impedance bandwidth and excellent isolation between its ports.
The gain of the antenna is comparable to that of a standard
circular microstrip antenna operating at the same resonant
frequency. A theoretical analysis for calculating the resonant
frequencies of the two ports is also presented
Mohanan,P; Aanandan,C K; K G Nair; Deepukumar,M; George,J(Department of Electronics, August 15, 1996)
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[-]
Abstract:
A new dual port microstrip antenna geometry for dual frequency
operation is presented. The structure consists of the intersection
of two circles of the same radius with their centres displaced by a
small fraction of the wavelength . This antenna provides wide
impedance bandwidth and excellent isolation between its ports.
The gain of the antenna is comparable to that of a standard
circular microstrip antenna operating at the same resonant
frequency. A theoretical analysis for calculating the resonant
frequencies of the two ports is also presented
Mohanan,P; Aanandan,C K; K G Nair(Department of Electronics, 1990)
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Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique. Compared to the available wide-band antenaas,
the proposed antenna structure Is very compact and gives a less
distorted radiation pattern with frequency . An impedance bandwidth,
eight times that of a conventional patch antenna of the same size, Is
achieved. The concept of coupled microstrip line model is extended for
theoretical interpretation of the impedance Loci
Aanandan,C K; K G Nair; Mohanan,P(Department of Electronics, October , 1990)
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Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique. Compared to the available wide-band antenaas,
the proposed antenna structure Is very compact and gives a less
distorted radiation pattern with frequency . An impedance bandwidth,
eight times that of a conventional patch antenna of the same size, Is
achieved. The concept of coupled microstrip line model is extended for
theoretical interpretation of the impedance loci
K G Nair; Aanandan,C K; Mohanan,P(Department of Electronics, 1990)
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Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique. Compared to the available wide-band antenaas,
the proposed antenna structure Is very compact and gives a less
distorted radiation pattern with frequency . An impedance bandwidth,
eight times that of a conventional patch antenna of the same size, Is
achieved. The concept of coupled microstrip line model is extended for
theoretical interpretation of the impedance Loci
Aanandan,C K; Mohanan,P; K G Nair(IEEE Journals/ Transactions (USA), 1990)
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Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique . Compared to the available
wide-baud antennas,the proposed antenna structure is very
compact and gives a lessdistorted radiation pattern with frequency .
An impedance bandwidth,eight times that of a conventional patch
antenna of the same size, Isachieved. The concept of coupled microstrip
line model Is extended fortheoretical interpretation of the impedance loci
Wang,Wel; Sheng,Bing Chen; Shun,Shi Zhong(Microwave and Optical Technology Letters, October 20, 2004)
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Abstract:
A novel slope -strip feeding technique for a microstrip
antenna is presented in order to achieve a broad bandwidth. The experimental
results show that the optimal bandwidth attained is 53.4% for
less than -10-dB return loss
Bybi, P C; Dr. Mohanan, P(Cochin University of Science & Technology, January , 2009)
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Abstract:
The Present thesis deals with the numerical as well as experimental investigations conducted on the resonance and radiation characteristics of Drum shaped monopole antenna, Funnel shaped monopole antenna and the shorted coplanar antenna.An introduction to the over view of antennas, state of the art planar antenna technologies, different feeding techniques and introduction of coplanar waveguides have been discussed.
Description:
Department of Electronics, Cochin University of Science and Technology
Biju Kumar, S; Aanandan, C K; Mathew, K T(John Wiley & Sons, October 5, 2001)
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Abstract:
The detection of buried objects using time-domain freespace
measurements was carried out in the near field. The location of a
hidden object was determined from an analysis of the reflected signal.
This method can be extended to detect any number of objects. Measurements
were carried out in the X- and Ku-bands using ordinary rectangular
pyramidal horn antennas of gain 15 dB. The same antenna was
used as the transmitter and recei er. The experimental results were
compared with simulated results by applying the two-dimensional
finite-difference time-domain(FDTD)method, and agree well with each
other. The dispersi e nature of the dielectric medium was considered for
the simulation.