Varkey,K P; Vijayakumar,K P(COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY, August , 1999)
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Abstract:
The study on the fabrication and characterization of spray pyrolysed cadmium sulphide homojunction solar cells. As an alternative to the conventional energy source, the PV technology has to be improved. Study about the factors affecting the performance of the existing solar cells and this will result in the enhancement of efficiency of the cells. At the same time it is equally important to have R&D works on developing new photovoltaic devices and processes which are less expensive for large scale production. CdS is an important binary compound semiconductor, which is very useful in the field of photovoltaics. It is very easy to prepare large area CdS thin films. In order to fabricate thin film homojunction cadmium sulphide cells, prepared and characterized SnO2 thin film as the lower electrode, p-CdS as the active layer and n-CdS as window layer. Cadmium material used for the fabrication of homojunction solar cells is highly toxic. The major damage due to continued exposure to low levels of cadmium are on the kidneys, lungs and bones. The real advantage of spray pyrolysis process is that there is no emission of any toxic gases during the deposition. Very low concentration of the chemicals is needed in this process. The risk involved from this material is very low, though they are toxic. On large scale usage it may become necessary that the cells after their life, should be bought back by the companies to retrieve chemicals like cadmium. This will reduce environmental problem and also the material wastage
Krishnan Nair, P R; Nandakumaran, V M(Cochin University of Science and Technology, October , 1999)
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Abstract:
This thesis is a study of discrete nonlinear systems represented by one dimensional mappings.As one dimensional interative maps represent Poincarre sections of higher dimensional flows,they offer a convenient means to understand the dynamical evolution of many physical systems.It highlighting the basic ideas of deterministic chaos.Qualitative and quantitative measures for the detection and characterization of chaos in nonlinear systems are discussed.Some simple mathematical models exhibiting chaos are presented.The bifurcation scenario and the possible routes to chaos are explained.It present the results of the numerical computational of the Lyapunov exponents (λ) of one dimensional maps.This thesis focuses on the results obtained by our investigations on combinations maps,scaling behaviour of the Lyapunov characteristic exponents of one dimensional maps and the nature of bifurcations in a discontinous logistic map.It gives a review of the major routes to chaos in dissipative systems,namely, Period-doubling ,Intermittency and Crises.This study gives a theoretical understanding of the route to chaos in discontinous systems.A detailed analysis of the dynamics of a discontinous logistic map is carried out, both analytically and numerically ,to understand the route it follows to chaos.The present analysis deals only with the case of the discontinuity parameter applied to the right half of the interval of mapping.A detailed analysis for the n –furcations of various periodicities can be made and a more general theory for the map with discontinuities applied at different positions can be on a similar footing
Kylasanatha Pillay,K P; Sadasivan Nair,G(COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY, 1999)
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Abstract:
This thesis is shows the result of the research work on the inherent Powers of the High Court in criminal jurisdiction. The criminal justice system in India recognizes inherent powers only of the High Court. The Theory and Philosophy of inherent powers are concerned the Distinction between civil and Criminal laws are of very little consequence. In formulating the research programme the confusion created by the concept of inherent powers and its application by High Court form the central point. How fully the concept is understood, how correctly the power is used, and how far it has enhanced the rationale of the administration of criminal justice, what is its importance and what are the solutions for the inherent power to earn a permanent status in the province of criminal jurisprudence are the themes of this study. The precipitation of new dimensions is the yardstick to acknowledge the inherent powers of the High Court and Supreme Court. It is of instant value in criminal justice system. This study concludes innovativeness provided by the inherent powers has helped the justice administration draw inspiration from the Constitution. A jurisprudence of inherent powers has developed with the weilding of inherent powers of the Supreme Court and the High Court. It is to unravel mystery of jurisprudence caused by the operation of the concept of inherent powers this research work gives emphasis. Its significance is all the more relevant when the power is exercised in the administration of criminal justice. Application or non application of inherent powers in a given case would tell upon the maturity and perfection of the standard of justice
Radhakrishnan, P; Girijavallabhan, C P; Nibu, A George; Aneeshkumar, B(Journal of Physics D : Applied Physics, April 7, 1999)
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Abstract:
The photobleaching of the lasing dye Rhodamine 6G embedded in the solid
matrix poly(methyl methacrylate) was investigated using a photoacoustic technique.
Chopped laser radiation from an argon ion laser at four different wavelengths was used for
the study. Experimental results indicate that the photobleaching rate is directly proportional
to the incident laser power while it decreases with increase in concentration of the dye
molecules. In the present case we have not observed any dependence of photobleaching on
the chopping frequency. One-photon absorption is found to be responsible for the
photobleaching of the dye within the selected range of laser power.
Krishna Kumar,P A; Chandramohanakumar,N(Cochin University of Science and Technology, October , 1999)
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Abstract:
This study focuses on the fractionation and quantification of chlorophenols, the most important and potential pollutant in this category, the distribution and seasonal dynamics of MBAS, phenols and clorophenols and development of a model to describe the chemical reactivity of the estuary are utilizing the dynamics of boron. The CES is highly influenced by various anthropogenic activities like discharge of agricultural, industrial and urban wastes operation of shipyard, oil and other transporting activities, fishing, dredging etc. Seasonal values of MBAS showed high values in the surface water during monsoon compared to premonsoon and postmonsoon. In the Cochin estuary o-chlorophenol and p-chlorophenol showed low values in the surface water compared to bottom water in the northern part of the estuary and higher values in the surface water in the southern part
Rani, Joseph(John Wiley & Sons, Inc., February 16, 1999)
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Abstract:
Microcellular (MC) soles based on polybutadiene (BR) and low-density
polyethylene (LDPE) blends for low-temperature applications were developed. A part of
BR in BR-LDPE blend was replaced by natural rubber (NR) for property improvement.
The BR-NR-LDPE blend-based MC sole shows good technical properties. Sulphur
curing and DCP curing were tried in BR-LDPE and NR-BR-LDPE blends. Study
shows that sulphur-cured MC sheets possess better technical properties than DCPcured
MC sheets. 90/10 BR-LDPE and 60/30/10 BR-NR-LDPE blend combinations are
found to be suitable for low-temperature applications.
Mridula,S; Jacob,George; Mohanan,P(Microwave and Optical Technology Letters, December 20, 1999)
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Abstract:
A novel antenna configuration comprised of two circular
micro strip antennas (CMAs) resonating in the TMtt and TM2, modes,
producing radiation characteristics suitable for a mobile telephone handset,
is presented. The antennas operating at the same frequency are
placed back to back with a separation comparable to the thickness of a
typical handset. The radiation pattern consists of a region of reduced
radiation intensity, which minimizes the radiation hazards to the user
Jianlang,Li; Liren,Liu; Yingchun,Guo; Huaisheng,Wang; Changhe,Zhou(Microwave and Optical Technology Letters, December 20, 1999)
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Abstract:
The transient interaction between a refraction index grating
and light beams during simultaneous writing and thermal fixing of
a photorefractive hologram is investigated. With a diffusion- and
photovoltaic-dominated carrier transport mechanism and carrier thermal
activation (temperature dependent) considered in Fe:LiNbO3 crystal, from
the standpoint of field-material coupling, the theoretical thermal fixing
time and the space-charge field buildup, spatial distribution, and temperature
dependence are given numerically by combining the band transport
model with mobile ions with the coupled-wave equation