A detailed study of the lithiation of iron phosphate as well as the development of a novel synthesis of lithium iron silicate as cathode material for lithium-ion batteries

Dans cette thèse nous démontrons le travail fait sur deux matériaux de cathodes pour les piles lithium-ion. Dans la première partie, nous avons préparé du phosphate de fer lithié (LiFePO4) par deux méthodes de lithiation présentées dans la littérature qui utilisent du phosphate de fer (FePO4) amorphe comme précurseur. Pour les deux méthodes, le produit obtenu à chaque étape de la synthèse a été analysé par la spectroscopie Mössbauer ainsi que par diffraction des rayons X (DRX) pour mieux comprendre le mécanisme de la réaction. Les résultats de ces analyses ont été publiés dans Journal of Power Sources. Le deuxième matériau de cathode qui a été étudié est le silicate de fer lithié (Li2FeSiO4). Une nouvelle méthode de synthèse a été développée pour obtenir le silicate de fer lithié en utilisant des produits chimiques peu couteux ainsi que de l’équipement de laboratoire de base. Le matériau a été obtenu par une synthèse à l’état solide. Les performances électrochimiques ont été obtenues après une étape de broyage et un dépôt d’une couche de carbone. Un essai a été fait pour synthétiser une version substituée du silicate de fer lithié dans le but d’augmenter les performances électrochimiques de ce matériau.

Comparative Studies on the Abundance of Zooplankton in the Surrounding Sea & Lagoons in the Lakshadweep

Composition and distribution of various groups and species of zooplankton at Kavaratti, Agatti and Suhelipar atolls of the Lakshadweep group of islands are reported . Higher biomass and diversity occur in the sea surrounding atolls compared to lagoons . Copepoda forms the dominant component of zooplankton . Zooplankton washed across the reef into the lagoon may be serving as food to the reef community . No fauna endemic to lagoons are encountered.

Anisotropy in elastic properties of lithium sodium sulphate hexahydrate single crystal—An ultrasonic study

The double sulfate family (ABSO4), where A and B are alkali metal cations, is the object of great interest owing to the complexity and richness of its sequence of phase transition induced by temperature variation. A new sulfate salt characterized by the presence of water molecule in the unit cell with the chemical formula, Li2Na3(SO4)2⋅6H2O (LSSW), was obtained. The ultrasonic velocity measurement was done with pulse echo overlap technique [PEO]. All the six second order elastic stiffness constants, C11 = C22, C33, C44 = C55, C12, C14 and C13 = C23 are reported for the first time. The anisotropy in the elastic properties of the crystal are well explained by the pictorial representation of the polar plots of phase velocity, slowness, Young’s modulus and linear compressibility in a–b and a–c planes.

STUDIES ON HAEMOLYMPH CONSTITUENTS OF INDOPLANORBIS EXUSTUS (DESHAYES) AND LYMNAEA ACUMINATA (LAMARCK) F.RUFESCENS (GRAY) AND THE EFFECTS OF COPPER ON THE ACTIVITY PATTERN OF SELECTED TRANSAMINASES AND PHOSPHATASES

The problem investigated is on the haematological aspects of two freshwater pulmonate snails, Indoplanorbis exustus (Deshayes),and Lymnaea acuminata f.rufescens (Gray). An important aspect of the present investigation is to emphasize the utilization of freshwater organisms as models for research directed at understanding the basic biomedical problems that remain unresolved. Another aspect is to demonstrate how haemolymph can be treated as a tissue because of late, it has been shown that several parameters of blood can be taken as reliable indicators for diagnostic purposes, and also to monitor environmental pollution. The various haematological parameters studied are total haemocyte number,packed cell volume, haemoglobin, and inorganic as well organic constituents in three size groups of both the snail species. The effect of copper toxicity was measured in terms of total haemocyte count, and the activity pattern of selected phosphatases and transaminases.The study concluded that enzyme activity levels can be taken as reliable indicators to monitor pollution. Age is a factor that determines several of the physiological, biochemical and metabolic activities. This study also indicates that haemolymph can be taken as an organ system to study the various changes taking place at organ systems levels.

STUDIES ON HAEMOLYMPH CONSTITUENTS OF PILA VIRENS (LAMARCK) AND THE EFFECTS OF PESTICIDES ON THE ACTIVITY PATTERN OF SELECTED ENZYMES

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.

DNA Interaction and Catalytic Activity Studies of Some New Transition Metal Complexes of Schiff Bases Derived from Quinoxaline

In this thesis we report the synthsis and characterisation of new transition metal complexes of Pd(II),Cu(II),Ru(II) and Ir(III) of Schiff bases derived from quinoxaline-2-carboxaldehyde/3-hydroxyquinoxaline-2-carboxaldehyde and 5-aminoindazole.6-aminoindazole or 8-aminoquinoline.The complexes have been characterised by spectral and analytical data.Pd(II) and Cu(II) form square planar complexes and Ru(III) and Ir(III) form ctahedral complexes with these Schiff bases.The DNA binding properties of theses synthesised complexes have been studied by various methods including electronic absoption spectroscopy,cyclic voltammetry,different pulse voltammetry and circular dichroism spectra were used.Gel electrophoresis experiments were also performed to investigate the DNA cleavage of theses complexes.Furthermore Ru(III) and Ir(III) complexes find application as oxidation and hydogenation catalsts. The studies on catalytic activities has been presented.The metal complexes presented in this thesis assure significance as they contribute to the development of new DNA binding agents and antibacterial and anticancer drugs.

Systematics, Germplasm evaluation and pattern of distribution and abundance of freshwater fishes of Kerala (lndia)

The overall focus of the thesis involves the systematics,germplasm evaluation and pattern of distribution and abundance of freshwater fishes of kerala (india).Biodiversity is the measure of variety of Life.With the signing on the convention on biodiversity, the countries become privileged with absolute rights and responsibility to conserve and utilize their diverse resources for the betterment of mankind in a sustainable way. South-east Asia along with Africa and South America were considered to be the most biodiversity rich areas in the world .The tremendous potential associated with the sustainable utilization of fish germplasm resources of various river systems of Kerala for food, aquaculture and ornamental purposes have to be fully tapped for economic upliftment of fisherman community and also for equitable sharing of benefits among the mankind without compromising the conservation of the rare and unique fish germplasm resources for the future generations.The study was carried during April 2000 to December 2004. 25 major river systems of Kerala were surveyed for fish fauna for delineating the pattern of distribution and abundance of fishes both seasonally and geographically.The results of germplasm inventory and evaluation of fish species were presented both for the state and also river wise. The results of evaluation of fish species for their commercial utilization revealed that, of the 145, 76 are ornamental, 47 food and 22 cultivable. 21 species are strictly endemic to Kerala rivers. The revalidation on biodiversity status of the fishes assessed based on IUCN is so alarming that a high percentage of fishes (59spp.) belong to threatened category which is inclusive of 8 critically ndangered (CR), 36 endangered and 15 species under vulnerable (VU) category.The river wise fish germplasm inventory surveys were conducted in 25 major river systems of Kerala.The results of the present study is indicative of existence of several new fish species in the streams and rivulets located in remote areas of the forests and therefore, new exclusive surveys are required to surface fish species new to science, new distributional records etc, for the river systems.The results of fish germplasm evaluation revealed that there exist many potential endemic ornamental and cultivable fishes in Kerala. It is found imperative to utilize these species sustainably for improving the aquaculture production and aquarium trade of the country which would definitely fetch more income and generate employment.

Studies on the distribution and abundance of fish eggs and larvae off the south—west coast of India with special reference to scombroids

The broad objective of the present study is to present a synoptic picture of the distribution and abundance of fish eggs and the lmportant groups of fish larvae obtained off the SW coast of India. so as to delineate the spawning areas and seasones of the fish population. with special reference to the scombroid fishes. An attempt was also made to correlate the occurrence of certain categories of larvae and hydrographical factors like temperature and salinity. The present effort was a pioneering one in Indian waters. in as much as it involved systematic and seasonally repetitive collection of ichthyoplankton from a large stretch of our seas and mapping of their distribution and abudance.

Geometric characterization of red blood cells. Differentiation of normal and pathologic samples

Introduction. Fractal geometry measures the irregularity of abstract and natural objects with the fractal dimension. Fractal calculations have been applied to the structures of the human body and to quantifications in physiology from the theory of dynamic systems.Material and Methods. The fractal dimensions were calculated, the number of occupation spaces in the space border of box counting and the area of two red blood cells groups, 7 normal ones, group A, and 7 abnormal, group B, coming from patient and of bags for transfusion, were calculated using the method of box counting and a software developed for such effect. The obtained measures were compared, looking for differences between normal and abnormal red blood cells, with the purpose of differentiating samples.Results. The abnormality characterizes by a number of squares of occupation of the fractal space greater or equal to 180; values of areas between 25.117 and 33.548 correspond to normality. In case that the evaluation according to the number of pictures is of normality, must be confirmed with the value of the area applied to adjacent red blood cells within the sample, that in case of having values by outside established and/or the greater or equal spaces to 180, they suggest abnormality of the sample.Conclusions. The developed methodology is effective to differentiate the red globules alterations and probably useful in the analysis of bags of transfusion for clinical use