K G Nair; Aanandan,C K; Mohanan,P(Department of Electronics, 1990)
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Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique. Compared to the available wide-band antenaas,
the proposed antenna structure Is very compact and gives a less
distorted radiation pattern with frequency . An impedance bandwidth,
eight times that of a conventional patch antenna of the same size, Is
achieved. The concept of coupled microstrip line model is extended for
theoretical interpretation of the impedance Loci
Aanandan,C K; K G Nair; Mohanan,P(Department of Electronics, October , 1990)
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Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique. Compared to the available wide-band antenaas,
the proposed antenna structure Is very compact and gives a less
distorted radiation pattern with frequency . An impedance bandwidth,
eight times that of a conventional patch antenna of the same size, Is
achieved. The concept of coupled microstrip line model is extended for
theoretical interpretation of the impedance loci
Mohanan,P; Aanandan,C K; K G Nair(Department of Electronics, 1990)
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[-]
Abstract:
A microstrip antenna with large bandwidth is developed
using a parasitic technique. Compared to the available wide-band antenaas,
the proposed antenna structure Is very compact and gives a less
distorted radiation pattern with frequency . An impedance bandwidth,
eight times that of a conventional patch antenna of the same size, Is
achieved. The concept of coupled microstrip line model is extended for
theoretical interpretation of the impedance Loci
Jayaraj, M K; Vallabhan, C P G(IOP Publishing, 1990)
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Abstract:
AC thin film electroluminescent devices of MIS and MISIM have been fabricated with a novel dielectric layer of Eu2O3 as an insulator. The threshold voltage for light emission is found to depend strongly on the frequency of excitation source in these devices. These devices are fabricated with an active layer of ZnS:Mn and a novel dielectric layer of Eu2O3 as an insulator. The observed frequency dependence of brightness-voltage characteristics has been explained on the basis of the loss characteristic of the insulator layer. Changes in the threshold voltage and brightness with variation in emitting or insulating film thickness have been investigated in metal-insulator-semiconductor (MIS) structures. It has been found that the decrease in brightness occurring with decreasing ZnS layer thickness can be compensated by an increase in brightness obtained by reducing the insulator thickness. The optimal condition for low threshold voltage and higher stability has been shown to occur when the active layer to insulator thickness ratio lies between one and two.
Reju, M K; Dr. Mohandas, A(Cochin University of Science & Technology, 1990)
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Abstract:
The present study is an attempt to understand the physiological responses of a freshwater gastropod, in terms of haematological parameters, in normal conditions as well as in various natural and man made altered conditions of the environment.Pila virens, a freshwater prosobranch,commonly found in paddy fields, ponds, and streams of Kerala is selected as the test animal for the present investigation. Various haemolymph constituents such as total carbohydrate, glycogen, total protein, total lipid, urea,ammonia,sodium,potasium, calcium, and chloride which are directly involved in the control and maintenance of different physiological systems, were analysed in the present study. Selected haematological parameters like total haemocyte number, and packed cell volume were also determined. Besides , the activity pattern of selected haemolymph enzymes such as acid phosphatase (ACP), alkaline phosphatase (ALP),Glutamate-oxaloacetate transaminase (GOT), and glutamate-pyruvate transaminase (GPT), all having diagnostic value in terms of internal defence system and metabolism of the organism, were also studied.
Description:
School of Environmental Studies,Cochin University of Science and Technology
Asok Kumar, K; Dr. Shahul Hameed, M(Cochin University of Science & Technology, 1990)
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Abstract:
The present study of the parasitic copepods gives the taxonomic description of thirty one species of parasites collected from various elasmobranch fishes of Kerala coast. Copepods parasitic on fishes include three sub orders, viz. poecilostomatoida, cyclopoida and siphonostomatoida. Parasitic copepods of elasmobranch fishes for the present study were collected from different fish landing centres of Kerala and by undertaking regular fishing trips. The collected parasites are identified to the species level and described. It is found that out of thirty one species, fifteen are new to science. They belong to the genera viz. Nothobomolochus Vervoot, 1962, Caligus Muller, 1785, Alebion, Kroyer, 1863, Gloipotes Steenstrup and Lutken, 1861, Pandarus Leach,1819, Perissopus Steenstrup and Lutken, 1861, Echthrogaleus Steenstrup and Lutken, 1861 and Kroyeria van Beneden, 1853. Fifteen new host records were reported. Two genera viz. Echthrogaleus and Entepherus were reported for first time from Indian waters. A new genus called Penicillus was erected. The general observations made during this study revealed certain interesting aspects of host-parasite relationship, host specificity, site specificity, adaptive modifications and geographical distribution.
Description:
Department of Industrial Fisheries, Cochin University of Science and Technology