Harikrishnan, K P; Nandakumaran, V M(Elsevier, November 21, 1988)
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Abstract:
We analyse numerically the bifurcation structure of a two-dimensional noninvertible map and show that different periodic cycles are arranged in it exactly in the same order as in the case of the logistic map. We also show that this map satisfies the general criteria for the existence of Sarkovskii ordering, which supports our numerical result. Incidently, this is the first report of the existence of Sarkovskii ordering in a two-dimensional map.
Bright Singh, I S; PhIlip, R; Sen, A; Rengarajan, R; Kumar, G S(1999)
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Abstract:
Whitespot virus could be experimentally transmitted from infected Penoeus monodon
to P. in.dicus and repeatedly passed on through several batches of apparently healthy J'.
in dieas. During these passages, white spots first disappeared before subsequently reappearing,
Electron microscopic studies revealed the presence of oblong-shaped, fully-assembled
virus towards the periphery and virus in paracrystalline arrnys towards the center
of the hypertrophied nuclei. The virus isolated here is referred to as whitespot syndrome
baculovirus (WSBV) until more is known of its antigenic .md genomic rclatodnc..s to
isolates from other countries
Description:
Aeiau Fisheries Science 12(1999):41-47
Asian Fisheries Society, Manila, Philippines
This paper explains the Genetic Algorithm (GA)
evolution of optimized wavelet that surpass the cdf9/7
wavelet for fingerprint compression and reconstruction.
Optimized wavelets have already been evolved in previous
works in the literature, but they are highly computationally
complex and time consuming. Therefore, in this work, a simple
approach is made to reduce the computational complexity of
the evolution algorithm. A training image set comprised of
three 32x32 size cropped images performed much better than
the reported coefficients in literature. An average
improvement of 1.0059 dB in PSNR above the classical cdf9/7
wavelet over the 80 fingerprint images was achieved. In
addition, the computational speed was increased by 90.18 %.
The evolved coefficients for compression ratio (CR) 16:1
yielded better average PSNR for other CRs also. Improvement
in average PSNR was experienced for degraded and noisy
images as well
Description:
2012 International Conference on Advances in Computing and Communications
Ambili, V; Narayana, A C(Cochin University of Science and Technology, October , 2010)
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Abstract:
Drainage basins are durable geomorphic features that provide insights into the long term evolution of the landscape. River basin geometry develop response to the nature and distribution of uplift and subsidence, the spatial arrangement of lineaments (faults and joints), the relative resistance of different rock types and to climatically influenced hydrological parameters . For developing a drainage basin evolution history, it is necessary to understand physiography, drainage patterns, geomorphic features and its structural control and erosion status. The present study records evidences for active tectonic activities which were found to be responsible for the present day geomorphic set up of the study area since the Western Ghat evolution. A model was developed to explain the evolution of Chaliar River drainage basin based on detailed interpretation of morphometry and genesis of landforms with special emphasis on tectonic geomorphic indices and markers.
Description:
Department of Marine Geology and Geophysics, Cochin University of Science and Technology
Anantharaman, M R; Pookat, G; Thomas, H; Thomas, S; Al-Harthi, S H; Raghavan, L; Al-Omari, I A; Sakthi Kumar, D; Ramanujan, R V(Elsevier, October 5, 2013)
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Abstract:
Ultra thin films based on CoFe were prepared from a composite target employing thermal evaporation. The
microstructure of the films was modified by thermal annealing. The relationship between microstructure and
magnetic properties of the films was investigated using techniques like glancing angle X-ray diffraction
(GXRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The GXRD and
TEM investigations showed an onset of crystallization of CoFe at around 373 K. The magnetic softness of the
films improved with thermal annealing but at higher annealing temperature it is found to be deteriorating.
Annealing inducedmodification of surface morphology of the alloy thin filmswas probed by atomic force microscopy
(AFM). Surface smoothening was observed with thermal annealing and the observed magnetic properties
correlate well with surface modifications induced by thermal annealing
Saleena, K B; Dr. Gopalakrishnan, N S(Cochin University of Science and Technology, October 19, 2011)
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Abstract:
This thesis entitled Exceptions and limitations to intellectual property rights with special reference to patent and copyright law.The study on the limitations and exceptions to copyright and patent was mainly characterized by its diversity and flexibility. The unique feature of limited monopoly appended to intellectual property was always a matter of wide controversy.The historical analysis substantiated this instrumentalist philosophy of intellectual property.the study from a legal space characterized by diversity and flexibility and end up in that legal space being characterized by homogeneity and standardization. The issue of flexibility and restrictiveness in the context of TRIPS is the next challenging task. Before devising flexibility to TST, the question to be answered is whether such a mechanism is desirable in the context of TRIPS.In conclusion it is submitted to reorient the intellectual property framework in the context of the noble public interest objectives.
Description:
School of Legal Studies, Cochin University of Science and Technology.
Anantharaman, M R; Thomas, S; Pookat, G; Nair, S S; Daniel, M; Dymerska, B; Liebig, A; Al-Harthi, S H; Ramanujan, R V; Fidler, J; Albrecht, M(IOP Publishing LTD, May 25, 2012)
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Abstract:
The magnetic properties of amorphous Fe–Ni–B based metallic glass nanostructures were
investigated. The nanostructures underwent a spin-glass transition at temperatures below
100 K and revealed an irreversible temperature following the linear de Almeida–Thouless
dependence. When the nanostructures were cooled below 25 K in a magnetic field, they
exhibited an exchange bias effect with enhanced coercivity. The observed onset of exchange
bias is associated with the coexistence of the spin-glass phase along with the appearance of
another spin-glass phase formed by oxidation of the structurally disordered surface layer,
displaying a distinct training effect and cooling field dependence. The latter showed a
maximum in exchange bias field and coercivity, which is probably due to competing multiple
equivalent spin configurations at the boundary between the two spin-glass phases
Lalitha, P R; Rao, V R; Nampoori, V P N(Current Science, 1980)
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Abstract:
Excitation and emission spectra of SrS : Mn : Ce phosphors have been studied in detail
at various Mn and Ce concentrations. In order to study the effect of external pressure on phosphors,
the samples were pretreated under various pressures. Four bands around 470 nm, 530 nm,
310 nm and 620 nm were observed, when the samples were excited with 265 nm radiation. The
effect of pressure is to reduce the fluorescence ability of the phosphors, and the luminescence
vanishes above O· 1 ton m-2 pressure. The fluorescence ability, however, can be regained on retiring
the sample. The emission mechanism has been attributed to two luminescentcenters in the forbidden
gap. An appreciable amount of photocurrent has also been observed for the sample.
Lo, H Y; Leung, K W(Microwave and Optical Technology Letters, June 5, 2001)
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Abstract:
A new configuration that employs a conducting conformal
strip to excite the low-profile equilaterial-triangular dielectric resonator
antenna (DRA) of very high permittivity is proposed. As compared with
the previous aperture-coupling configuration, the new configuration has
a wider impedance bandwidth (- 5.5%) and a higher front-to-back
radiation ratio. The return loss, radiation patterns, and antenna gain are
measured and discussed
Kailasnath, M; Nishant, Kumar; Nampoori, V P N; Vallabhan, C P G; Radhakrishnan, P(Elsevier, 2008)
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Abstract:
Dependence of energy transfer parameters on excitation wavelength has been investigated in poly (methyl methacrylate) (PMMA) optical fibre preforms doped with C 540:Rh B dye mixture by studying the fluorescence intensity and the lifetime variations. A fluorescence spectrophotometer was used to record the excitation spectra of the samples for the emission wavelengths 495 and 580 nm. The fluorescence emission from the polymer rods was studied at four specific excitation wavelengths viz; 445, 465, 488 and 532 nm. The fluorescence lifetime of the donor molecule was experimentally measured in polymer matrix by time correlated single photon counting technique. The energy transfer rate constants and transfer efficiencies were calculated and their dependence on the acceptor concentration was analysed for three excitation wavelengths. It was found that any change in the excitation wavelength leads to significant variations in the quenching characteristics, which in turn affect the calculated energy transfer parameters.
Radhakrishnan, P; Nampoori, V P N; Litty, Irimpan; Bindu, Krishnan; Deepthy, A(Journal of Physics D : Applied Physics, August 30, 2007)
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Abstract:
In this paper, the fluorescence behaviour of nano colloids of ZnO has been
studied as a function of the excitation wavelength. We have found that
excitation at the tail of the absorption band gives rise to an emission that
shifts with the change of the excitation wavelength. The excitation
wavelength dependent shift of the fluorescence maximum is measured to be
between 60 and 100 nm. This kind of excitation wavelength dependent
fluorescence behaviour, which may appear to be in violation of Kasha’s rule
of excitation wavelength independence of the emission spectrum, has been
observed for nano ZnO colloids prepared by two different chemical routes
and different capping agents. It is shown that the existence of a distribution
of energetically different molecules in the ground state coupled with a low
rate of the excited state relaxation processes, namely, solvation and energy
transfer, are responsible for the excitation wavelength dependent
fluorescence behaviour of the systems.
Nampoori, V P N; Radhakrishnan, P; Litty, Irimpan; Bindu, Krishnan; Deepthy, A(Journal of Physics D : Applied Physics, August 30, 2007)
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Abstract:
In this paper, the fluorescence behaviour of nano colloids of ZnO has been
studied as a function of the excitation wavelength. We have found that
excitation at the tail of the absorption band gives rise to an emission that
shifts with the change of the excitation wavelength. The excitation
wavelength dependent shift of the fluorescence maximum is measured to be
between 60 and 100 nm. This kind of excitation wavelength dependent
fluorescence behaviour, which may appear to be in violation of Kasha’s rule
of excitation wavelength independence of the emission spectrum, has been
observed for nano ZnO colloids prepared by two different chemical routes
and different capping agents. It is shown that the existence of a distribution
of energetically different molecules in the ground state coupled with a low
rate of the excited state relaxation processes, namely, solvation and energy
transfer, are responsible for the excitation wavelength dependent
fluorescence behaviour of the systems.
Krishnan Nair, P R; Nandakumaran, V M(Springer, October , 1998)
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Abstract:
We present the analytical investigations on a logistic map with a discontinuity at the
centre. An explanation for the bifurcation phenomenon in discontinuous systems is presented. We
establish that whenever the elements of an n-cycle (n > 1) approach the discontinuities of the nth
iterate of the map, a bifurcation other than the usual period-doubling one takes place. The periods of
the cycles decrease in an arithmetic progression, as the control parameter is varied. The system also
shows the presence of multiple attractors. Our results are verified by numerical experiments as well.
Bindhu, C V; Harilal, S S; Nampoori, V P N; Vallabhan, C P G(Springer-Verlag, 2000)
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Abstract:
Optical limiting and thermal lensing studies are
carried out in C70–toluene solutions. The measurements are
performed using 9-ns pulses generated from a frequencydoubled
Nd:YAG laser at 532 nm. Optical limiting studies in
fullerene molecules lead to the conclusion that reverse saturable
absorption is the major mechanism for limiting. Analysis
of thermal lensing measurements showed a quadratic
dependence of thermal lens signal on incident laser energy,
which also supports the view that optical limiting in C70 arises
due to sequential two-photon absorption via excited triplet
state (reverse saturable absorption).