Sheelu,Varghese; Bake,Shameena; Lakshmy,P S; Biju,M P; Eswar Shankar,P N; Paulose,C S; Oommen,V Oommen(Department of Bio Technology, August 27, 2001)
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Abstract:
The effects of feeding of 6-propyllhiouracil (6-I'fU) and potyunsaturatcd fatty acids (I'UFA) independently and ill
combination and administration (ip) of a single close of Iriiodothyronine (I',) (2.51ig/IOOg body wl) along with feeding of 6-
PTU and PUFA were studied in cal brain. Dopamine (DA), 5-hydroxytryplophan (5-IIl'I'), serolouin (5-Ill), 5-hydioxy indole
acetic acid (5-111AA), norepinephrine (NF) :uul ceinephrinn (I?I'l) contenls were assayed in the hypothalannls and ccrc
bral cortex regions. It was found that 6-P"l'U Iccding resulted in decrease in dopamine, 5-III', 5 II I I' and 5 IIiAA in both
regions. In animals fed wills PUFA followed by adnliuislralion of T,. the I)A level was found normal.
Hsieh,Gui-Bin; Chen,Ming-Huang; Wong,Kin-Lu Wong(IEE Electronics letters,UK, June 21, 2001)
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Abstract:
A novel technique for obtaining dual-hand circular polarization
(CP) radiation of a single-feed circular microstrip antenna in
proposed and demonstrated. By embedding two pain of arc shaped
slots of proper lengths close to the boundary of a circular
patch, and protruding one of the arc-shaped slots with a narrow
slit, the circular microstrip antenna can perform dual-hand CP
radiation using a single probe feed. Details of the antenna design
V P N Nampoori; Radhakrishnan, P; Girijavallabhan, C P; Nibu, A George; George, A K(Applied Physics B Lasers and Optics, June 18, 2001)
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Abstract:
In this paper, we describe the use of an open cell
photoacoustic configuration for the evaluation of the thermal
effusivity of liquid crystals. The feasibility, precision and reliability
of the method are initially established by measuring
the thermal effusivities of water and glycerol, for which the
effusivity values are known accurately. In order to demonstrate
the use of the present method in the thermal characterization
of liquid crystals, we have measured the thermal
effusivity values in various mesophases of 4-cyano-4 -
octyloxybiphenyl (8OCB) and 4-cyano-4 -heptyloxybiphenyl
(7OCB) liquid crystals using a variable temperature open
photoacoustic cell. A comparison of the measured values for
the two liquid crystals shows that the thermal effusivities of
7OCB in the nematic and isotropic phases are slightly less
than those of 8OCB in the corresponding phases
Paulson,M; Sona,Kundukulam O; Aanandan,C K; Mohanan,P(Department of Electronics, September , 2001)
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Abstract:
The arrow shaped microstrip antenna, which produces
dual frequency dual polarisation operation with considera-ble size reduction compared to conventional patches has been
reported [I]. These antennas provide greater area reduction and
improved gain compared to drum shaped patches [2]. Prediction
of the resonance frequency of drum shaped patches [3] and circular
patches for broadband operation [4] are available in the literature.
In this Letter, we propose empirical formulas for calculating
the resonance frequencies of the arrow shaped microstrip antenna.
These antennas can be employed for obtaining dual frequency
with the same polarisation, bandwidth enhancement, circular
polarisation etc. by varying its different parameters or by introducing
slots. The proposed design equations provide an easier and
simple way of predicting the resonant frequencies of these patches.
A simple technique for calculating the resonance frequencies of a
compact arrow-shaped microstrip antenna is presented and discussed . The accuracy of the method is validated by experimental results
Abdel, Fattah Sheta(Microwave and Optical Technology Letters, April 5, 2001)
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Abstract:
A novel H-shaped patch antenna suitable for wireless and
satellite communications is presented. The new antenna has some advantages
compared to conventional microstrip patch antennas, such as
small size, a fewer number of modes, no harmonic resonance, and the
provision of pure reactive impedances at its harmonics that can result in
increasing the transmitter efficiency. The basic principles and design
procedure are introduced. Two antennas at two different frequencies, 4
and 10 GHz, are designed, fabricated, and measured. The measured
results show a good agreement with the predicted ones
Vermeeren,G; Rogier,H; Olyslager,F; Zutter De,D(IEE Electronics letters,UK, September 13, 2001)
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Abstract:
A single-feed rectangular-ring microstrip antenna is proposed for
indoor communication under the Bluetooth protocol. The
dimensions of the antenna together with the location of the feed
point are optimized through field simulations in order to cover the
Bluetooth bandwidth and to avoid linear polarization. The
performance and the efficiency of the antenna are illustrated in a
real indoor environment
Mohammed Yusuff,K K; Ahmed Yasir,Vakayil; Mohandas,P N(Elsevier, International Journal of Inorganic Materials, August 12, 2001)
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Abstract:
Highly crystalline, ultra fine TiO (anatase) having high surface area has been prepared by thermal hydrolysis of titanyl sulphate 2
solution and characterized using B.E.T surface area measurements, XRD and chemical analysis. The dependence of surface area on
concentration of staffing solution, temperature of hydrolysis, duration of boiling and calcination temperature were also studied. As the
boiling temperature, duration of boiling and calcination temperature increased, the surface area of TiO formed decreased significantly. 2
On increasing calcination temperature, the crystallite size of TiO also increased and gradually the phase transformation to rutile took 2
place. The onset and completion temperatures of rutilation were 700 and 10008C, respectively
Dielectric properties of polyaniline at different frequencies were studied. Cavity perturbation technique was employed for the
study. Poly aniline in the powder and pelletised forms were prepared under different environmental conditions. Different samples of
poly aniline exhibit high conductivity. However, the conductivity of samples prepared under different environmental conditions is
found to vary. All the samples in the powder form have high conductivity irrespective of the method of preparation. The high
conductivity at microwave frequency makes it possible to be used for developing microwave components like filters.
Sugunan, S; Renuka, N K(Indian Journal of Chemistry, February , 2001)
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Abstract:
Vapour phase methylation of phenol is carried out over La2O3 supported vanadia systems of various composition. The structural features and physico chemical characterisation of the catalysts are investigated. Orthovanadates are formed in addition to surface vanadyl species on the metal oxide support. No V2O5 crystallites are detected. The acid base properties of the oxides are studied by Hammett indicator method and decomposition of cyclohexanol.The data are correlated with the catalytic activity and selectivity of the products. Ring alkylation is found to be predominant over these catalysts.