Ponnachan,P T C; Paulose,C S; Panikkar,K R(Department of Biotechnology, 1991)
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Abstract:
Alloxan induced diabetic animal model was
sed to evaluate the potential antidiabetic effect of
ie aqueous leaf extract of Aegle marmelose. Insuinjection
and oral treatment of Aegle marmelose
of extract to the alloxan induced rats maintained
;e animal weight near to the control rats whereas
,,ere was a significant decrease in weight in alloxan
•duced rats. Insulin injection and oral treatment
the leaf extract reversed the decrease of protein
)ntent in all the organs studied except the pancas.
Glucose level was maintained near to the co-
:rol levels in the insulin injected and leaf extract
Bated alloxan diabetic rats. A significant increased
ucose tolerance was observed in animals orally
ven the leaf extract prior to the experiment. The
suits indicate that there is an increased utilization
glucose in the Aegle marmelose leaf extract treed
rats.
Rani, Joseph(Huthig & Wepf Verlag, Basel, June 5, 1991)
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Abstract:
Antioxidants were attached to hydroxy-terminated liquid natural rubber by modified
Friedel-Crafts alkylation reaction using anhydrous zinc chloride as catalyst. The rubber
bound antioxidants were found to be less volatile and less extractable compared to
conventional antioxidants. The bound antioxidants were tried both in latex compounds
and dry rubber compounds. The vulcanizates showed improved ageing resistance
compared to vulcanizates based on conventional antioxidants.
Sunil K Narayanankutty(Elsevier Science Publishers Ltd., August 29, 1991)
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Abstract:
The thermal degradation of short kevlar fibre-thermoplastic polyurethane
(TPU) composites has been studied by Thermogravimetric Analysis (TGA)
and Differential Scanning Calorimetry (DSC). TGA showed that the thermal
degradation of TPU takes place in two steps with peak maxima (T1max and
T2ma,) at 383°C and 448°C, respectively. In the presence of 10-40 phr of short
kevlar fibres, T1_ and T2max were shifted to lower temperatures. The
temperature of onset of degradation was increased from 245 to 255°C at 40
parts per hundred rubber (phr) fibre loading. Kinetic studies showed that the
degradation of TPU and kevlar-TPU composite follows first-order reaction
kinetics. The DSC study showed that there is an improvement in thermal
stability of TPU in the presence of 20 phr of short kevlar fibres.
Design and development of a new feed -horn antenna
with low sidelobe levels is reported . The E-walls of this
antenna are fabricated with low -loss dielectric substrate ,
periodicallyloaded with thin conducting strips . The antenna
is found to be simulating the radiation characteristics of metallic
Corrugated horns . This can be an ideal substitute for metallic
Corrugated horns with added advantages like light -weight and low
production cost
Sangster,A J(Microwave and Optical Technology Letters, September , 1991)
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Abstract:
A new microstrip antenna element is described which exhibits polarization
agility. This is achieved by employing a T-slot radiator
which is driven by the edge fields of a balanced microstrip line. The
balanced line can support two propagating modes. namely. an even
mode and an odd mode, and be switching between these modes. the
orthogonal arms of the T-slot radiator are separately excited thus
forming orthogonally polarized radiated fields. A nucrostrip patch
antenna, which displays polarization agility using the sane mechanism,
is also described
Mohanan, P; K G Nair; Stephen, Rodrigues(Department of Electronics, November , 1991)
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Abstract:
Design and development of a new feed -horn antenna
with low sidelobe levels is reported . The E-walls of this
antenna are fabricated with low -loss dielectric substrate , periodically
loaded with thin conducting strips . The antenna is found
to be simulating the radiation characteristics of metallic corrugated
horns . This can be an ideal substitute for metallic corrugated
horns with added advantages like light -weight and low
production cost.
K G Nair; Mohanan, P; Stephen, Rodrigues(Department of Electronics, 1991)
[+]
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Abstract:
Design and development of a new feed -horn antenna
with low sidelobe levels is reported . The E-walls of this
antenna are fabricated with low -loss dielectric substrate , periodically
loaded with thin conducting strips . The antenna is found
to be simulating the radiation characteristics of metallic corrugated
horns . This can be an ideal substitute for metallic corrugated
horns with added advantages like light -weight and low
production cost.
Sunil K Narayanankutty(Gordon and Breach Science Publishers, December 10, 1991)
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Abstract:
Tear and wear properties of short kevlar fiber, thermoplastic polcurethane (TPU) composite with
respect to fiber loading-and fiber onentation has been studied and the fracture surfaces were examined
under scanning electron microscope (SEM). Tear strength first decreased up to 20 phr fiber loading
and then gradually increased with increasing fiber loading. Anisotropy in tear strength was evident
beyond a fiber loading of 20 phr. Tear fracture surface of unfilled TPU showed sinusoidal folding
characteristics of high strength matrix. At low fiber loading the tear failure was mainly due to fibermatrix failure whereas at higher fiber loading the failure occurred by fiber breakage. Abrasion loss
shows a continuous rise with increasing fiber loading, the loss in the transverse orientation of fibers
being higher than that in the longitudinal orientation. The abraded surface showed lone cracks and
ridges parallel to the direction of abrasion indicating an abrasive wear mechanism. In the presence of
fber the abrasion loss was mainly due to fiber low.
Thomas, Baby; Sathianandan, K; Nampoori, V P N; Vallabhan, C P G; Ramachandran, T(American Institute of Physics, September , 1991)
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Abstract:
A high power Nz laser of the double-Blumlein type having a modified gas flow system,
electrode configuration, and discharge geometry with minimum inductance is described. By
incorporating a triggere’d-pressurized spark gap switch, arc-free operation was achieved
for a wide E/P range. The device gives a peak power in excess of 700 kW with a FWHM of
3 ns and an efficiency of 0.51%, which is remarkably high for a pulsed nitrogen laser
system. The dependence of output power on parameters such as operating pressure, voltage,
and repetition rate are discussed.
The design and development of an L-band printed dipole antenna.
optimized for wide-band applications near first resonance, is reported.
This design has achieved more than 48% impedance bandwidth
(VSWR 2:1), without degrading its overall radiation efficiency