INVESTIGATIONS ON THE RECOVERY OF TITANIUM VANADIUM AND IRON VALUES FROM THE WASTE CHILORIDE LIQUORS OF TITANIA INDUSTRY

The thesis entitled INVESTIDGATIONS ON THE RECOVERY OF TITANIUM VANADIUM AND IRON VALUES FROM THE WASTE CHILORIDE LIQUORS OF TITANIA INDUSTRY embodies the results of the investigations carried out on the solvent extraction separation of iron (III) vanadium(V) and titanium (IV) chlorides from the waste chloride liquors of titanium minerals processing industry by employing tributylphosphate (TBT) as an extractant. The objective of this study is to generate the knowledge base to achieve the recovery of iron, vanadium and titanium cvalues from multi- metal waste chloride liquors originating from ilmenite mineral beneficiation industries through selective separation and value added material development

Neuroendocrinology of Pyridoxine Deficiency

Veuruenducrim lri v j p .rim, deficienc:v. NEUROSCI BIOBEHAV REV 12(3/4) 189-193. 1988.- Dihydroxyphenylalanine decarboxvlase and 5-hydroxytryptophan decarboxvlase respectively have high and low affinities for pyridoxal phosphate. In the pyridoxinedeficient animal. hypothalamic serotonin content is significantly reduced without any change in catecholamine levels. Hypothalamic neurotransmitters affect the hvpothalamo-pituitary-end organ axes. Specifically, the decrease in hypothalamic serotonin in the pyridoxine-deficient rat results in tertiary hypothyroidism. In addition. pineal function is affected in deficient animals due to decreased synthesis of melatonin.

Hypertension in Pyridoxine Deficiency

Pyridoxal phosphate (PLP) is the coenzyme of various decarboxylases involved in the formation of monoamine urotransmitters such as y-aminobulyric acid (GAE3A), serotonin (5-HT) and dopamine. 1-lowever; in the pyridoxine-deficient rats GABA and 5-HT are decreased in various brain areas including the hypothalamus, with no change in the catecholamine levels. Serotonin and GABA are known to be involved in blood pressure control mechanisms. In this study adult Sprague-Dawley rats placed on a pyridoxine-deficient diet for 8 weeks showed significant hypertension compared with pyridoxine-supplemented controls. This was associated with a general sympathetic stimulation. Treatment of deficient rats with a single dose of pyridoxine (10 mg/kg body weight) reversed the blood pressure to normal levels within 24 h, with concomitant restoration of hypothalamic 5-HT and GABA, as well as the return of plasma norepinephrine to nornr;l levels. The results indicate that there is a cause-and-effect relationship between pyridoxine deficiency and hypertension.

Effect of Pyridoxine Deficiency in Young-Rats on High-Affinity Serotonin and Dopamine Receptors

The high-affinity bindings of [3H]-5-hydroxytryptamine to serotonin S-1 receptors, [3H]-ketanserin to serotonin S-2 receptors in the cerebral cortex, [3H]- fluphenazine to dopamine D-1 receptors, and [3H]-spiroperidol to dopamine D-2 receptors in the corpus striatum were studied in pyridoxine-deficient rats and compared to pyridoxine-supplemented controls. There was a significant increase in the maximal binding (Bmax) of serotonin S-1 and S-2 receptors with a significant decrease in their binding affinities (Kd). However, there were no significant changes either in the maximal binding or binding affinity of striatal dopamine D- 1 and D-2 receptors. Receptor sensitivity seems to correlate negatively with the corresponding neurotransmitter concentrations in the pyridoxine-deficient rats.

Studies on Chemical Bath Deposited Semiconducting Copper Selenide and Iron Sulfide Thin Films Useful For Photovoltaic Applications

Chemical bath deposition (CBD)is one of the simplest, very convient and probably the cheapest method for thin film preparation. Photovoltaic is the cleanest and the most efficient mode of conversion of energy to electrical power. Silicon is the most popular material in this field. The present study on chemical bath deposited semiconducting copper selenide and iron sulfide thin films useful for photovoltaic applications. Semiconducting thin films prepared by chemical deposition find applications as photo detectors, solar control coatings and solar cells. Copper selenide is a p-type semiconductor that finds application in photovolitics. Several heterojunction systems such as Cu2-xSe/ZnSe (for injection electro luminescence), Cu2Se/AgInSe2 and Cu2Se/Si (for photodiodes), Cu2-xSe/CdS, Cu2-xSe/CdSe, CuxSe/InP and Cu2-xSe/Si for solar cells are reported. A maximum efficiency of 8.3% was achieved for the Cu2-xSe/Si cell, various preparation techniques are used for copper selenide like vacuum evaporation, direct reaction, electrodeposition and CBD. Instability of the as-prepared films was investigation and is accounted as mainly due to deviation from stoichiometry and the formation of iron oxide impurity. A sulphur annealing chamber was designed and fabricated for this work. These samples wee also analysed using optical absorption technique, XPS (X-ray Photoelectron Spectroscopy) and XRD.(X-Ray Diffraction).The pyrite films obtained by CBD technique showed amorphous nature and the electrical studies carried out showed the films to be of high resistive nature. Future work possible in the material of iron pyrite includes sulphur annealing of the non-stochiometric iron pyrite CBD thin films in the absence of atmospheric oxygen

Studies on Magnetic Iron Oxide Loaded Activated Carbon

The current water treatment technology is oriented towards the removal of contaminants, mostly organic compounds, by activated carbon. Activated carbons are classified as Granular Activated Carbons (GAC) and Powdered Activated Carbons (PAC) on the basis of the particle size of the carbon granules. Powdered carbons are generally less expensive than granular carbon, operating costs with powdered carbon could be lower. Though powdered activated carbon has many advantages over granular carbon, its application in large-scale separation process is limited by difficulty in recovery and regeneration. Deposition of magnetic iron oxide on carbon particles provides a convenient way of recovering the spent carbon from process water. The study deals with the preparation and physico-chemical characterization of magnetic iron oxide loaded activated carbons. The evaluation of absorption properties of magnetic iron oxide loaded activated carbon composites. The target molecules studied were phenol, p-nitro phenol and methylene blue. The feasibility of magnetic separation of iron oxide loaded activated carbons were studied and described in this thesis.

Synthesis, characterisation and benzylation activity of vanadia impregnated iron pillared montmorillonite

Iron pillared Montmorillonite has been synthesised and it is then wet impregnated with vanadia with different vanadia composition. These catalysts are characterised using conventional techniques such as XRD analysis,FTIR analysis and surface area and pore volume measurements. Acidity is measured using spectrophotometric monitoring of adsorption of perylene, thermogravimetric desorption of 2.6 dimethylpyridine and temperature programmed desorption of ammonia. Activity studies are done in the liquid phase. It has been concluded that Lewis acidic sites are responsible for the benzylation of toluene when the benzylating agent is benzyl chloride while Bronsted acidic sites are responsible when the reagent is benzyl alcohol.

Iron Promoted Sulphated Zirconia Systems as Efficient Catalysts for Phenol Hydroxylation

The present work investigates on the applicability of metal promoted sulphated zirconia catalysts for the hydroxylation of phenol under mild conditions. The percentage conversion and product distribution was highly sensitive towards the reaction parameters like the catalyst composition, reaction temperature, H202/ phenol ratio and the solvent used.

Liquid phase benzoylation of arenes over iron promoted sulphated zirconia

The present work undertakes the preparation and physico-chemical characterisation of iron promoted sulphated zirconia (SZ) with different amounts of iron loading and their application to Friedel-Crafts benzoylation of benzene, toluene and xylene under different experimental conditions, XRD and laser Raman techniques reveal the stabilisation of the tetragonal phase of zirconia and the existence of iron in highly dispersed form as Fe203 on the catalyst surface. The surface acidic properties were determined by ammonia temperature programmed desorption (TPD) and perylene adsorption, The results were supported by the TGA studies after adsorption of pyridine and 2,6-dimethylpyridine (2,6-DMP), Strong Lewis acid sites on the surface, which are evident from TPD and perylene adsorption studies. explain the high catalytic activity of the systems towards benzoylation. The experimental results provide evidence for the truly heterogeneous nature of the reaction. The studies also establish the resistance to deactivation in the metal incorporated sulphated systems.

Template assisted fabrication of I-D nanostructures of Nickel,Cobalt, Iron Oxide and Carbon nanotubes and a study on their structural, magnetic and nonlinear optical properties for applications

Department of Physics, Cochin University of Science & Technology

Professional Services: Civil Liability for Deficiency

This study deals the professional Services civil Liability for deficiency with special reference to medical professionals.the study deals with the characteristics of profession,basis of liability , historical evolution of legal controls on professional services, liability of doctors for negligence under tort law. Expectations to liability for medical negligence are critically evaluated. consent of medical treatment etc are studied

Colour Removal From Dye-House Efiluents Using Zero-Valent iron and Fenton Oxidation

This thesis Entitled Colour removal from dye house effluents using zero valent iron and fenton oxidation.Findings reported on kinetic profile during oxidation of dyes with Fenton’s reagent are in good agreement with observations of earlier workers on other organic substrates. This work goes a step further. Critical concentration of the dye at which the reaction mechanism undergoes transition has been identified.The oxidation of Reactive Yellow showed that the initial rates for decolorization increased linearly with an increase in hydrogen peroxide concentration over the range studied. Fenton oxidation of all dyes except Methylene Blue showed that the initial rates increased linearly with an in the ferrous sulphate concentration. This increase was observed only up to an optimum concentration beyond which further increase resulted in a decrease in the initial rates. Variation of initial rates with Ferrous sulphate concentration resulted in a linear plot passing through the origin indicating that the reaction is first order with respect to ferrous sulphate.

On the synthesis and magnetic properties of multiwall carbon nanotube– superparamagnetic iron oxide nanoparticle nanocomposites

Multiwall carbon nanotubes (MWCNTs) possessing an average inner diameter of 150 nm were synthesized by template assisted chemical vapor deposition over an alumina template. Aqueous ferrofluid based on superparamagnetic iron oxide nanoparticles (SPIONs) was prepared by a controlled co-precipitation technique, and this ferrofluid was used to fill the MWCNTs by nanocapillarity. The filling of nanotubes with iron oxide nanoparticles was confirmed by electron microscopy. Selected area electron diffraction indicated the presence of iron oxide and graphitic carbon from MWCNTs. The magnetic phase transition during cooling of the MWCNT–SPION composite was investigated by low temperature magnetization studies and zero field cooled (ZFC) and field cooled experiments. The ZFC curve exhibited a blocking at ∼110 K. A peculiar ferromagnetic ordering exhibited by the MWCNT–SPION composite above room temperature is because of the ferromagnetic interaction emanating from the clustering of superparamagnetic particles in the constrained volume of an MWCNT. This kind of MWCNT–SPION composite can be envisaged as a good agent for various biomedical applications

Strain induced anomalous red shift in mesoscopic iron oxide prepared by a novel technique

Nano magnetic oxides are promising candidates for high density magnetic storage and other applications. Nonspherical mesoscopic iron oxide particles are also candidate materials for studying the shape, size and strain induced modifications of various physical properties viz. optical, magnetic and structural. Spherical and nonspherical iron oxides having an aspect ratio, ~2, are synthesized by employing starch and ethylene glycol and starch and water, respectively by a novel technique. Their optical, structural, thermal and magnetic properties are evaluated. A red shift of 0⋅24 eV is observed in the case of nonspherical particles when compared to spherical ones. The red shift is attributed to strain induced changes in internal pressure inside the elongated iron oxide particles. Pressure induced effects are due to the increased overlap of wave functions. Magnetic measurements reveal that particles are superparamagnetic. The marked increase in coercivity in the case of elongated particles is a clear evidence for shape induced anisotropy. The decreased specific saturation magnetization of the samples is explained on the basis of weight percentage of starch, a nonmagnetic component and is verified by TGA and FTIR studies. This technique can be modified for tailoring the aspect ratio and these particles are promising candidates for drug delivery and contrast enhancement agents in magnetic resonance imaging