Authority and development: leadership, development and democracy in African urban areas

Paper presented at the Wits History Workshop: Democracy, Popular Precedents, Practice and Culture, 13-15 July, 1994

Decomposition of Bis(N-benzyl-salicydenaminato)zinc (II) Complex for the Synthesis of ZnO Nanoparticles to Fabricate ZnO-Chitosan Nanocomposite for the Removal of Iron (II) Ions from Wastewater

The whole world is faced with a huge challenge of the shortage of clean water due to industrialization and the intimidation of climate change. Poor water quality distresses many areas of human’s well-being. Although there are existing technologies for water treatments, many of these methods utilize toxic substances which create more problems into the environment. The preparation of bis(N-benzyl-salicydenaminato)zinc (II) complex and the synthesis of zinc oxide nanoparticles via the thermal decomposition of zinc complex together with the fabrication of ZnO-chitosan nanocomposites for the removal of iron (II) ions from wastewater is reported. The optical properties of the synthesized nanoparticles showed band edges that are red-shifted in wavelengths when the decomposition temperature was increased. The XRD patterns displayed the hexagonal ZnO phase for the synthesized nanoparticles. TEM images revealed spherical-shaped particles which became agglomerated when the temperature was increased. The parameters such as pH, contact time, and initial concentration were investigated during the water treatment. The pH = 6 was found to be optimum, and the highest percentage removal was recovered after three hours for both adsorbents

PLANIFICATION STRATÉGIQUE ET FORMES ÉMERGENTES DE DÉMOCRATIE À ETHEKWINI, DURBAN

Through a case study of development policy making in the eThekwini metro (Durban), South Africa, this paper explores the emergence of post apartheid forms of local democracy. The paper examines the production of strategic planning documents in the years following the creation of the municipality in 2000 and maps out the variety and effect of major influences on these documents. These influences include city officials, public participation, elected representatives, traditional leaders, businesses and provincial and national party networks.South Africa, local government, participation, strategic planning

The Influence of Temperature on the Formation of Cubic Structured CdO nanoparticles and their Thin Films from bis(2-hydroxy-1-naphthaldehydato)cadmium(II) complex via Thermal Decomposition Technique

Recently, researchers have developed a great interest in the synthesis of metal oxide nanoparticles due to their potential applications in various fields of science and industry, especially in catalysis, due to their high activity. Bis(2-hydroxy-1-naphthaldehydato)cadmium(II) complexes were prepared and used as precursors for the synthesis of cadmium oxide nanoparticles via thermal decomposition method using HDA as a stabilizing agent. The prepared complexes were also used as single source precursors to prepare CdO thin films onto the glass substrates by spin coating and were annealed at 250, 300, and 350°C, respectively. The precursors were characterized by Fourier transform infrared (FTIR) spectroscopy, elemental analysis, nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). The synthesized CdO nanoparticles and CdO thin films were characterized by ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM)

The Influence of Temperature on the Formation of Cubic Structured CdO nanoparticles and their Thin Films from bis(2-hydroxy-1-naphthaldehydato)cadmium(II) complex via Thermal Decomposition Technique

Recently, researchers have developed a great interest in the synthesis of metal oxide nanoparticles due to their potential applications in various fields of science and industry, especially in catalysis, due to their high activity. Bis(2-hydroxy-1-naphthaldehydato)cadmium(II) complexes were prepared and used as precursors for the synthesis of cadmium oxide nanoparticles via thermal decomposition method using HDA as a stabilizing agent. The prepared complexes were also used as single source precursors to prepare CdO thin films onto the glass substrates by spin coating and were annealed at 250, 300, and 350°C, respectively. The precursors were characterized by Fourier transform infrared (FTIR) spectroscopy, elemental analysis, nuclear magnetic resonance (NMR), and thermogravimetric analysis (TGA). The synthesized CdO nanoparticles and CdO thin films were characterized by ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM)

Magnetite Functionalized Nigella Sativa Seeds for the Uptake of Chromium(VI) and Lead(II) Ions from Synthetic Wastewater

The aim of the present study was to utilise pristine and magnetite-sucrose functionalized Nigella Sativa seeds as the adsorbents for the uptake of chromium(VI) and lead(II) ions from synthetic wastewater. Prestine Nigella Sativa seeds were labelled (PNS) and magnetite-sucrose functionalized Nigella Sativa seeds (FNS). The PNS and FNS composites were characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The FTIR analysis of both adsorbents revealed the presence of vibrations assigned to 1749 and 1739 cm-1 (-C=O) for ketonic group for both adsorbents. The amide (-NH) peak was observed at 1533 and 1527 cm-1 on FNS and PNS composites, respectively, whilst the carboxyl group (-COOH) were observed at 1408 cm-1 on both adsorbents. The XRD results of FNS and PNS composites showed a combination of spinel structure and y-Fe2O3 phase confirming the formation of iron oxide. The influence of operational conditions such as initial concentration, temperature, pH, and contact time was determined in batch adsorption system. The kinetic data of Cr(VI) and Pb(II) ions on both adsorbents was described by pseudo-first-order (PFO) model which suggested physisorption process. The sorption rate of Cr(VI) ions was quicker, it attained equilibrium in 20 min, and the rate of Pb(II) ions was slow in 90 min. Freundlich isotherm described the mechanism of Pb(II) ions adsorption on PNS and FNS composites. Langmuir best fitted the uptake of Cr(VI) ions on PNS and FNS. The results for both adsorbents showed that the removal uptake of Pb(II) ions increased when the initial concentration was increased; however, Cr(VI) uptake decreased when the initial concentration increased. The adsorption of Cr(VI) and Pb(II) ions on both adsorbents increased with temperature

The influences of the concentrations of “green capping agents” as stabilizers and of ammonia as an activator in the synthesis of ZnS nanoparticles and their polymer nanocomposites

Abstract The green synthetic route for the synthesis of semiconductor nanoparticles has received special attention recently due to its features, such as low cost and environmental friendliness. The (Z)-2-(pyrrolidin-2-ylidene)thiourea was used as a ligand and allowed to react with zinc acetate to form the ZnS nanoparticles through the homogeneous precipitation method. The polyvinyl pyrrolidone and polyethylene glycol were employed as capping agents, whereas the ammonium solution was used as an activator for the stabilizers. The effects of the concentration of the capping agents on ZnS nanoparticles were investigated. The poly ethylene glycol (PEG)- or (polyvinylpyrollidone) PVP-capped zinc sulfide nanoparticles were then incorporated with polydadmac to form the polymer nanocomposites. The results from various sophisticated instruments, such as spectrophotometer (UV-Vis), photoluminescence (PL), Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), transmission electron microscope (TEM), and scanning electron microscopy (SEM), reveal that the concentrations of capping agents and ammonium solution has great effects on nanomaterials.</jats:p