Gopikrishna, M; Dr.Aanandan, C K(Cochin University of Science & Technology, July , 2010)
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Abstract:
A major challenge in the transmission of narrow pulses is the radiation characteristics
of the antenna. Designing the front ends for UWB systems pose challenges
compared to their narrow and wide band counterparts because in addition to
having electrically small size, high efficiency and band width, the antenna has
to have excellent transient response. The present work deals with the design
of four novel antenna designs- Square Monopole, Semi-Elliptic Slot, Step and
Linear Tapered slot - and an assay on their suitability in UWB Systems. Multiple
resonances in the geometry are matched to UWB by redesigning the ground-patch
interfaces. Techniques to avoid narrow band interference is proposed in the
antenna level and their effect on a nano second pulse have also been investigated.
The thesis proposes design guidelines to design the antenna on laminates of any
permittivity and the analyzes are complete with results in the frequency and time
domains.
Description:
Department of Electronics,
Cochin University of Science and Technology
Sagar, S; Dr.Anantharaman, M R(Cochin University of Science & Technology, August , 2010)
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Abstract:
This thesis lays importance in the investigation on the multiferroic and
thermooelectric properties of selected representatives of low bandwidth and
intermediate band width manganites. The first candidate, Strontium doped Gd manganite, is prepared by wet solid state reaction method and the second
candidate, Na doped La manganite, by citrate gel method. In addition to the above
mentioned properties, magneto resistance and dielectric properties are
investigated. Using dielectric spectroscopic the dispersion parameters are
correlated to the relaxation mechanisms and an attempt is made to obtain the grain
and grain boundary contribution to the impedance of the sample through
impedance spectroscopy studies.
Description:
Department of Physics,
Cochin University of Science & Technolog
Toms C, Joseph; Dr.Surendran, P K; Dr. Nirmala, Thampuran(Central Institute of Fisheries Technology, January , 2010)
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Abstract:
This thesis covers various aspects of viral diseases affecting shrimp aquaculture. The
research component of this thesis can be divided into four areas. The areas covered are: I) A
study to determine the prevalence of WSSV among the crustaceans in the Vembanad estuary, the
shrimp aquaculture farms surrounding the estuary, and the sea off Cochin coast, India using two
, sets of nested PCR primers. 2) An investigation to compare the sequence of six major structural
proteins of WSSV; vp28, vp26, vp 19, vp68, vp281, vp466 from different geographical locations
with that of an isolate from India. 3) Simultaneous occurrence of HPV, IHHNV, MBV and
WSSV in postlarvae of P. monodon from hatcheries in India was monitored by Polymerase
Chain Reaction. 4) A real time PCR procedure was developed for the quantitative analysis of
WSSV infection. The viral load of postlarvae from hatcheries in Kerala meant for aquaculture
was also determined using the quantitative PCR.