Beyer,G J; Hagebo,E; Novgorodov,A F; Ravn,H L(EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH, November 7, 2002)
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Abstract:
On line isotope separation techniques (ISOL) for production of ion beams of short-lived radionuclides
require fast separation of nuclear reaction products from irradiated target materials followed by a transfer into
an ion source. As a first step in this transport chain the release of nuclear reaction products from refractory
metals has been studied systematically and will be reviewed. High-energy protons (500 - 1000 MeV) produce
a large number of radionuclides in irradiated materials via the nuclear reactions spallation, fission and
fragmentation. Foils and powders of Re, W, Ta, Hf, Mo, Nb, Zr, Y, Ti and C were irradiated with protons
(600 - 1000 MeV) at the Dubna synchrocyclotron, the CERN synchrocyclotron and at the CERN PS-booster
to produce different nuclear reaction products.
The main topic of the paper is the determination of diffusion coefficients of the nuclear reaction products
in the target matrix, data evaluation and a systematic interpretation of the data. The influence of the ionic
radius of the diffusing species and the lattice type of the host material used as matrix or target on the
diffusion will be evaluated from these systematics. Special attention was directed to the release of group I, II
and III-elements. Arrhenius plots lead to activation energies of the diffusion process.
Indulal,G; Vijayakumar,Ambat(Department of Mathematics, 2002)
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Abstract:
Two graphs G and H are Turker equivalent if they have the same set of Turker angles.
In this paper some Turker equivalent family of graphs are obtained.
Merlin,Joseph; Meera Bai,M(Department of Applied Economics, Faculty of Social Sciences, 2002)
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Abstract:
The overall objective of the study is to examine the problems and prospects of the tea on industry in Kerala. The specific objectives are to trace the historical evolution of the tea plantation industry in India with special reference to Kerala and to study the performance of tea plantation industry in Kerala. In order to analyse the growth performance of tea plantation industry in Kerala in a comparative perspective, growth rates for the neighbouring states of Karnataka and Tamilnadu are estimated along with the National, South Indian and North Indian estimates. Tea plantation industry is a labour intensive activity. Productivity has been low primarily because of the over aging. In all the factories visited only Black tea is produced. In factories outmoded machines which installed years ago is still used which will increase the cost of production. The major problem is high cost of production and low price realization. The workers are found to be not satisfied with their working conditions- long journey to work place, absence of resting places, latrine facilities etc. and also the problems arising from dust in the factory. At a macro level the tea plantation industry has been facing the adverse impacts of globalisation and trade liberalization. There is only one solution to this problem that is to improve the competitiveness in production of raw leaf and manufacturing of tea. Government has a very important role with specification of strict quality control
Sona,Kundukulam O; Paulson,M; Aanandan,C K; Mohanan,P; K G Nair(Department of Electronics, October , 2002)
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Abstract:
A dual-port microstrip antenna with a crescent shaped
patch with excellent isolation betwecn the ports has been reportcd [I].
Since circular-sided geometries are inore compact than rectangular
oncs, thcy find morc applications in microstrip arrays. The crcscent
shaped antenna geometry [ I ] provides greater area rcductioii compared
to other circular sided patches for broadband operation [2]. In this
Lctter, formulac for calculating thc TM, I and TMZI mode resonant
frequencies of this microstrip antenna, obtained by modifying the
equations of a standard circular patch [3] are presentcd. Thcorctical
results are compared with experimental observations aid the validity
of the computation is established.
Sona,Kundukulam O; Manju,Paulson; Aanandan,C K; Mohanan,P(Microwave Engineering Group,Department of Electronics, April 20, 2002)
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Abstract:
Design equations are presented for calculating the resonance frequencies for a
compact dual frequency arrow-shaped microstrip antenna. This provides a fast and simple
way to predict the resonant frequencies of the antenna. The antenna is also analyzed using the
IE3D simulation package. The theoretical predictions are found to be very close to the
IE3D results and thus establish the validity of the design formulae
Shaju,P D; Kuriakose,V C(Cochin University of Science and Technology, 2002)
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Abstract:
The thesis deals with detailed theoretical analysis of fluxon dynamics in single and in coupled Josephson junctions of different geometries under various internal and external conditions. The main objective of the present work is to investigate the properties of narrow Long Josephson junctions (LJJs) and to discuss the intriguing physics. In this thesis, Josephson junctions of three types of geometries, viz, rectangular, semiannular and quarter annular geometries in single and coupled format are studied to implement various fluxon based devices. Studies presented in this thesis reveal that mulistacked junctions are extremely useful in the fabrication of various super conducting electronic devices. The stability of the dynamical mode and therefore the operational stability of the proposed devices depend on parameters such as coupling strength, external magnetic fields, damping parameters etc. Stacked junctions offer a promising way to construct high-TC superconducting electronic components. Exploring the complex dynamics of fluxons in coupled junctions is a challenging and important task for the future experimental and theoretical investigations
Geetha,R; Chandramohanakumar,N(Department of Chemical Oceanography,School of marine sciences, 2002)
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Abstract:
The mangrove ecosystem is one of the earth’s most endangered ecosystems. In this study, geochemical features of three mangrove ecosystems, Mangalavanam, Vypeen and Nettoor were compared. Water, sediment and core samples were collected from these stations for a period of one year. Nutrients, organic compounds orgnic carbon and hydrographical parameters of the samples were estimated. The present study revealed higher concentration of carbon in the surface sediments. The major temporary or ultimate sink for various pollutants in estuaries is the sedimentary reservoir, including intertidal areas. In the present study, higher values for dissolved nutrients, POC and carbohydrates were observed during low tide.