Anantharaman, M R; Asha, Mary John; Mathew, George; Swapna, Nair S; Joy, P A(Elsevier, October 10, 2005)
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Abstract:
Nanoparticles of nickel ferrite have been synthesized by the sol–gel method and the effect of grain size on its structural and magnetic
properties have been studied in detail. X-ray diffraction (XRD) studies revealed that all the samples are single phasic possessing the
inverse spinel structure. Grain size of the sol–gel synthesized powders has been determined from the XRD data and the strain graph. A
grain size of 9 nm was observed for the as prepared powders of NiFe2O4 obtained through the sol–gel method. It was also observed that
strain was induced during the firing process. Magnetization measurements have been carried out on all the samples prepared in the
present series. It was found that the specific magnetization of the nanosized NiFe2O4 powders was lower than that of the corresponding
coarse-grained counterparts and decreased with a decrease in grain size. The coercivity of the sol–gel synthesized NiFe2O4 nanoparticles
attained a maximum value when the grain size was 15nm and then decreased as the grain size was increased further.
Description:
Journal of Magnetism and Magnetic Materials 302 (2006) 190–195
Gopalakrishna Pillai,N; Dr.Damodaran,R(Cochin University of Science And Technology, December , 1978)
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Abstract:
In this thesis a detailed sampling is conducted using grabs and dredges to access the qualitative
and quantitative nature of the macrobenthos. A11 the animal contributing to the fauna are identified and their pattern of distribution and seasonal abundance are discussed. Affinity and diversity of polychaete fauna have also been studied. Importance of different benthic forms and their contribution to the standing crop are studied in detail. Trophic relationship between macrofauna and botton feeding commercially important fishes and prawns are also
given attention. The physico-chemical aspects or the environment have been studied and their relation to the distribution and abundance of bottom fauna has been discussed. Environmental
parameters such as temperature. salinity and dissolved oxygen. both in bottom and in the overlying waters. and rainfall were studied along with the benthos investigations. The physico-chemical nature of the sediments was also subjected to investigation. Influence of
all those ecological parameters on the bottom fauna is discussed. A detailed quantitative faunal list of maorobenthio species and a brief systematic account of the polychaeta are also given.
Description:
School of marine sciences, Cochin University of Science And Technology