Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 74 for “"540 Chemistry & allied sciences"”.
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Biochemistry of micro-polutants in sediments of Mtoni estuary, Tanzania
In order to describe and evaluate the past and current status, and predict the future status of mangrove ecosystem in relation to changing human activities in the coastal areas and its environment in Tanzania, mangrove sediments from the Mtoni estuary were analysed for elemental (C, N) and isotopic …
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Assessment of Bioactivity of Se-lected Plants against Pests and Microbes from Agro-pastoral Communities in Mbulu District, Tanzania
This study intended to have an ethnobotanical inventory of medicinal and pesticidal plant species and their bioactivities and toxicity against selected bacteria, fungi and storage pests. Bioactivities (antimicrobial and antioxidant activities) against disease causing organisms, toxicity against …
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Levels of Heavy metals in Soil, Water, and Plants and Variation of water Quality Parameters at Vikuge in Kibaha District, Tanzania
The levels of toxic heavy metals ( cadmium, lead, copper, zinc, chromium and iron) were checked in soil, water, plant leaves, fruits and roots obtained at Vikuge in Kibaha, Tanzania. The samples of water from the three wells were taken in triplicate, similar to the samples of plants, fruits and …
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Studies on the residue chemistry of some organophosphorus pesticides
… plan of working has involved synthetic organic chemistry and analytical chemistry related to specific studies on two organophosphorus pesticides, viz. Q, Q-diethyl -(K-ethosycarbonyl-8-methylcarbamoylmethyl) phosphorodithioate (common name mecarbam) and 0, G-diethyl S-chloromethyl …
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Electrochemistry and photochemistry of sulphonium salts
The cleavage in aqueous solution of the C-S+ bond in a series of related sulphonium salts having a benzyl ligand has been investigated: (i) electrochemically (ground state), (ii) photochemically (excited state). (i) Most of the sulphonium salts examined reduced in the same general manner: the …
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Kinetics of hydrogen evolution and absorption during electrochemical reactions as determined by monitoring the volume of hydrogen bubbles
The piezo electric technique (P.E.T) devised in this department is a highly sensitive method for measuring the total volume of gas bubbles suspended in a solution. This is achieved by simply performing a static compressibility test, causing small pressure fluctuations in the volume of a solution …
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Synthesis and characterisation of novel α-functionalised phosphoryl derivatives
This thesis focuses on the synthesis and study of α-aminoalkylphosphinic acids, α-aminoalkylphosphonic acids and macrocycles containing these sub-units. There are two broad types of macrocyclic systems that are targeted: (i) C-functionalised α-aminophosphonic acids; and (ii) N-functionalised …
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Studies of quinone monooximes derived from dihydroxyphenylalanines
This thesis is concerned with the nitrosation behaviour of 1,5-, 1,6- and 2,7-dihydroxynaphthalenes towards equimolar and excess sodium nitrite/acid. The direct and indirect methods of nitrosations have been used to prepare mono- and di-nitrosated products. Under all experimental conditions …
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Lanthanide complexes of phthalimide and phthalamate containing ligands: synthesis, photophysical properties and their potential applications
Molecular sensors and switches have made important contributions to biomedical devices and molecular computational operations. There are numerous molecular designs using a fluorophore linked through a spacer group to a receptor(s), with a wide dynamic range, directional precision, target …
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Studies of the role of ligands in determining the structures of polynuclear metal compounds
… in the solid state and how this relates to the chemistry of the cluster in solution.
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Metal complexes of 1,2-quinone monooximes and their applications in organic synthesis
Systematic investigations of the reactions of 1,2-quinone monooximes (qoH) with alkali (lithium, sodium and potassium) and alkaline earth metal (magnesium and barium) hydroxides and acetates [M(OH)n or M(OAc)r] have been carried out.
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Structural studies of polynuclear metal carbonyl derivatives
X-Ray structure analysis of fifteen metal carbonyl cluster compounds of nuclearity three to seven have been carried out to investigate the effect organo-fragments have on metal core geometry.
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Synthesis and chemistry of 1,4-oxathianes and 1,4-oxathian-3-ones
The exploration of possible routes towards the synthesis of alkylated oxathiane and oxathianone systems are presented in this research thesis. The ultimate objective of these studies was the synthesis of dihydrofurans and dihydrofuranones via the Ramberg-Bäcklund rearrangement. Initially, studies …
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Preparative and NMR studies of polyphosphorus ligands and their complexes
Synthetic routes have been developed for the ready preparation of a range of novel polyphosphorus ligands containing up to seven potential donor atoms.
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An experimental investigation of diffuse optical scattering from stationary and flowing dispersions
This Thesis describes the measurement and interpretation of diffuse optical scattering from concentrated colloidal dispersions. Novel measurement techniques using optical fibres are investigated. These are applied to monodisperse spherical latexes where the results are compared with theories of …
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Synthesis and biological activities of [alpha]-aminoalkanephosphonic acids and [alpha]-aminoalkanephosphonous acids and their derivatives
A study of preparation methods for alpha-aminoalkanephosphonic, alpha-aminoalkanephosphonous and alpha-aminoalkanephosphinic acids has been made, based on the combined use of an aldehyde, an amino com pound, and a phosphorus reagent. Reported yields are frequently poor and the mechanisms of the …
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The synthesis of aminophosphonic acid derivatives & related compounds
1-Aminoalkanephosphonic acids and their derivatives, have long been claimed to be compounds with a wide variety of application. Numerous examples exist where they have been described as: complex-forming agents with sequestrating properties, extractants, wetting agents, pharmaceutical preparations, …
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The development of new methods for the assessment of oxygen radical-mediated oxidative damage to biomolecules with special reference to lipids
The involvement of chemically-reactive oxygen radical species (RORS) in the pathogenesis of inflammatory joint diseases has been well documented. Much of the toxicity produced by increased superoxide ion (O2.-) and hydrogen peroxide (H2O2) generation has been attributed to the production of the …
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The reactions of esters of phosphorus (III) acids with electrophilic reagents
Reactions of highly hindered phosphorus (III) esters derived from 2,2,2-triphenylethanol, 2,2-diethylbutan-1-o1, and norbornan -1-o1 with electrophilic reagents, in particular, α-haloketones were studied by P and pH spectroscopy.
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Studies of the metal-binding sites in macrocyclic quadridentate ligands
The preparations of quadridentate macrocyclic ligands with N4-, O2N2- and S2N2-donor-sets are described.
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