Devassia, V P; Dr. Tessamma, Thomas(Cochin University of Science & Technology, December , 2003)
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Abstract:
During 1990's the Wavelet Transform emerged as an important signal processing tool with potential applications in time-frequency analysis and non-stationary signal processing.Wavelets have gained popularity in broad range of disciplines like signal/image compression, medical diagnostics, boundary value problems, geophysical signal processing, statistical signal processing,pattern recognition,underwater acoustics etc.In 1993, G. Evangelista introduced the Pitch- synchronous Wavelet Transform, which is particularly suited for pseudo-periodic signal processing.The work presented in this thesis mainly concentrates on two interrelated topics in signal processing,viz. the Wavelet Transform based signal compression and the computation of Discrete Wavelet Transform. A new compression scheme is described in which the Pitch-Synchronous Wavelet Transform technique is combined with the popular linear Predictive Coding method for pseudo-periodic signal processing. Subsequently,A novel Parallel Multiple Subsequence structure is presented for the efficient computation of Wavelet Transform. Case studies also presented to highlight the potential applications.
Description:
Department of Electronics, Cochin University of Science and Technology
Bindhu, C V; Harilal, S S; Riju C, Issac; Nampoori, V P N; Vallabhan, C P G(World Scientific Puhlishing Company, 1996)
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Abstract:
Pulsed photoacoustic technique which is found to be a very convenient and accurate method, is used for the determination of absolute fluorescence quantum yield of laser dye rhodamine B. Concentration and power dependence of quantum yield of rhodamine B in methanol for excitation at 532 nm is reported here. Results show that a rapid decrease in quantum yield as the concentration is increased and finally it reaches the limit corresponding to fluorescence quenching.
Bindhu, C V; Harilal, S S; Issac, Riju C; Geetha K, Varier; Nampoori, V P N; Vallabhan, C P G(Pramana, March , 1995)
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Abstract:
Pulsed photoacoustic measurements have been carried out in toluene at 532 nm
wavelength using a Q-switched frequency doubled Nd:YAG laser. The variation of photoacoustic
signal amplitude with incident laser power indicates that at lower laser powers one
photon absorption takes place at this wavelength while a clear two photon absorption occurs in
this liquid at higher laser powers. The studies made here demonstrate that pulsed photoacoustic
technique is simple and effective for the investigation of multiphoton processes in
liquids.
The propagation of pulse waves in coplanar waveguides
(CPWs) is investigated, and these CPWs are assumed to be fabricated
on a single -layer low- temperature co-fired ceramic (LTCC) substrate.
The input pulse wave can be a Gaussian pulse or a sinusoldally modulated
Gaussian pulse. Based on the standard Galerkin 's method in the
spectral domain, combined with fast Fourier transform (FFT), the pulse
waveform and delay in CPWs are demonstrated and compared for a second plate, oriented orthogonally to the primary planar element,
thus producing a crossed planar monopole (CPM), which is
simpler to produce and has lower cost than a conical monopole. In
this paper, further measurements have been made on this element
Archana, Kishore; Dr. Sarita G, Bhat(Cochin University of Science and Technology, March , 2007)
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Abstract:
The temperate, filamentous phage ФMV -5 isolated from Mangalavanam
mangrove of Kochi, using the environmental strain of Vibrio sp. MV-5 shares
many similar properties with other marine phage isolates, while also remaining
unique. The study has revealed that the interaction of temperate phages and the
microbial population in the marine environment may contribute significantly to
microbial genetic diversity and composition by conversion and transduction and
which requires greater study.Prophages contribute a substantial share of the mobile DNA of their
bacterial hosts and seem to influence the short-term evolution of pathogenic
bacteria. Automated methods for systematic investigation of prophages and other
mobile DNA elements in the available bacterial genome sequences will be
necessary to understand their role in bacterial genome evolution. In the past,
phages were mainly investigated as the simplest model systems in molecular
biology. Now it is increasingly realized that phage research will be instrumental in
the understanding of bacterial abundance in the environment. One can predict that
phage research will impact diverse areas such as geochemistry and medicine.
Success will largely depend on integrative multidisciplinary approaches in this
field. Clearly, further studies are required to understand how vibriophages interact
with Vibrios to promote this organism's acquisition of the critical genes which alter
its virulence or adaptation to its environmental niche.It is evident from this study and comparison with those reports cited above
that vibriophage ФMV-5 is a previously unreported bacteriophage. It is
recommended that the minimum requirement for reporting a new phage should be
novel morphological markers and a description of host range, both of which have
been achieved in this study.
Description:
Department of Biotechnology,
Cochin University of Science and Technology
Girish Kumar,K; Remalakshmy,Poduval; Sareena,John; Pearl,Augustine(Departmenrt of Applied Chemistry, May 11, 2006)
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Abstract:
A new PVC membrane sensor, which is
highly selective towards Ni (II) ions, has been developed
using a thiophene-derivative Schiff base as the
ionophore. The best performance was exhibited by the
membrane having the composition percentage ratio of
5:3:61:31 (ionophore:NaTPB:DBP:PVC) (w=w), where
NaTPB is the anion excluder, sodium tetraphenylborate
and DBP is the plasticizing agent (dibutyl phthalate).
The membrane exhibited a good Nernstian response for
nickel ions over the concentration range of 1.0 10 1–
5.0 10 6M (limit of detection is 1.8 10 6 M) with a
slope of 29.5 1.0mV per decade of activity. It has a
fast response time of<20 s and can be used for a period
of 4 months with good reproducibility. The sensor is
suitable for use in aqueous solutions of a wide pH range
of 3.2–7.9. The sensor shows high selectivity to nickel
ions over a large number of mono-, bi- and trivalent
cations. It has been successfully used as an indicator
electrode in the potentiometric titration of nickel ions
against EDTA and also for direct determination of
nickel content in real samples – wastewater samples
from electroplating industries and Indian chocolates.
Girish Kumar,K; Remalakshmy,Poduval; Sareena,John; Pearl,Augustine(Department of Applied Chemistry, May 11, 2006)
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Abstract:
A new PVC membrane sensor, which is
highly selective towards Ni (II) ions, has been developed
using a thiophene-derivative Schiff base as the
ionophore. The best performance was exhibited by the
membrane having the composition percentage ratio of
5:3:61:31 (ionophore:NaTPB:DBP:PVC) (w=w), where
NaTPB is the anion excluder, sodium tetraphenylborate
and DBP is the plasticizing agent (dibutyl phthalate).
The membrane exhibited a good Nernstian response for
nickel ions over the concentration range of 1.0 10 1–
5.0 10 6M (limit of detection is 1.8 10 6 M) with a
slope of 29.5 1.0mV per decade of activity. It has a
fast response time of<20 s and can be used for a period
of 4 months with good reproducibility. The sensor is
suitable for use in aqueous solutions of a wide pH range
of 3.2–7.9. The sensor shows high selectivity to nickel
ions over a large number of mono-, bi- and trivalent
cations. It has been successfully used as an indicator
electrode in the potentiometric titration of nickel ions
against EDTA and also for direct determination of
nickel content in real samples – wastewater samples
from electroplating industries and Indian chocolates.
Girish Kumar,K; Pearl,Augustine; Sareena,John; Beena,Saraswathyamma(Department of Applied Chemistry, June 12, 2006)
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Abstract:
new PVC membrane ion selective electrode which is highly selective towards Ni(II) ions was constructed using a
Schiff base containing a binaphthyl moiety as the ionophore. The sensor exhibited a good Nernstian response for nickel
ions over the concentration range 1.0 × 10–1 – 5.0 × 10–6 M with a lower limit of detection of 1.3 × 10–6 M. It has a fast
response time and can be used for a period of 4 months with a good reproducibility. The sensor is suitable for use in
aqueous solutions in a wide pH range of 3.6 – 7.4 and works satisfactorily in the presence of 25% (v/v) methanol or
ethanol. The sensor shows high selectivity to nickel ions over a wide variety of cations. It has been successfully used as
an indicator electrode in the potentiometric titration of nickel ions against EDTA and also for the direct determination of
nickel content in real samples: effluent samples, chocolates and hydrogenated oils.
PVC supported liquid membrane and carbon paste potentiometric sensors incorporating an Mn(III)-porphyrin
complex as a neutral host molecule were developed for the determination of paracetamol. The measurements were
carried out in solution at pH 5.5. Under such conditions paracetamol exists as a neutral molecule. The mechanism of
molecular recognition between the Mn(III)-porphyrin and paracetamol, leading to potentiometric signal generation,
is discussed.The sensitivity and selectivity toward paracetamol of carbon paste and polymeric liquid membrane electrodes
incorporating an Mn(III)-porphyrin host were compared. The applicability of these sensors to the direct
determination of paracetamol was checked by performing a recovery test in human plasma.
Premnath, R; Dr. Madhu, G(Cochin University of Science & Technology, November , 2011)
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Abstract:
Data centre is a centralized repository,either physical or virtual,for the storage,management and dissemination of data and information organized around a particular body and nerve centre of the present IT revolution.Data centre are expected to serve uniinterruptedly round the year enabling them to perform their functions,it consumes enormous energy in the present scenario.Tremendous growth in the demand from IT Industry made it customary to develop newer technologies for the better operation of data centre.Energy conservation activities in data centre mainly concentrate on the air conditioning system since it is the major mechanical sub-system which consumes considerable share of the total power consumption of the data centre.The data centre energy matrix is best represented by power utilization efficiency(PUE),which is defined as the ratio of the total facility power to the IT equipment power.Its value will be greater than one and a large value of PUE indicates that the sub-systems draw more power from the facility and the performance of the data will be poor from the stand point of energy conservation. PUE values of 1.4 to 1.6 are acievable by proper design and management techniques.Optimizing the air conditioning systems brings enormous opportunity in bringing down the PUE value.The air conditioning system can be optimized by two approaches namely,thermal management and air flow management.thermal management systems are now introduced by some companies but they are highly sophisticated and costly and do not catch much attention in the thumb rules.
Description:
Division of Safety and Fire Engineering,School of Engineering,Cochin University of Science and Technology
A dynamical system with a damping that is quadratic in velocity is converted into the Hamiltonian format using a nonlinear transformation. Its quantum mechanical behaviour is then analysed by invoking the Gaussian effective potential technique. The method is worked out explicitly for the Duffing oscillator potential.
Bybi, P C; Jitha, B; Aanandan, C K; Vasudevan, K; Mohanan, P; Gijo, Augustin(Antennas and Wireless Propagation Letters, IEEE, 2008)
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Abstract:
A compact, planar, wideband antenna designed by modifying the coplanar waveguide is presented in this letter. The proposed antenna finds a wide range of applications including advanced wireless systems (AWS), DCS-1800, DCS-1900/PCS/PHS, WiBro, BlueTooth/WLAN/WiBree/ZigBee, DMB, Global Star Satellite Phones, and digital cordless phones. Wide bandwidth > 75% centered at 2.50 GHz, quasi-omnidirectional radiation coverage along with moderate gain and efficiency are the salient features of the antenna. A prototype fabricated on a substrate with dielectric constant 4.4 and thickness 1.6 mm occupies an area of (31times 64) mm2. Details of antenna design and discussions on the effect of various antenna parameters on the radiation characteristics are presented.