An investigation into the use of whistle-blowing as a means to curb unethical behaviour of police officers in the Nelson Mandela Bay

The use of whistle-blowing as means to curb unethical behaviour of police officers in the Nelson Mandela Bay is investigated in this study. In order to investigate this, various instruments were used, these are interviews and questionnaires. However the objectives of the study were: - To examine the implementation of whistle-blowing in the SAPS. - To develop strategies and measures that can be used to encourage whistle-blowing in the SAPS. Broadly speaking, these objectives have been achieved by providing empirical evidence which shows that: - Unethical behaviour by police officers is the most ethical challenge facing police officers in the Nelson Mandela Bay Area. This is based on the findings which eminate from the interviews. - Whistle-blowing is used by police officers as an early warning system that alerts the superiors about misconduct before it is too late as it defects and deters wrongdoing. However, the study suggests various strategies and measures to assist the implementation of whistle-blowing. These strategies include: - Development of hotlines. - Assurance of confidentiality and anonymity of disclosures. - Response plan development. - Training development. - Regarding whistle-blowing as an ongoing communication. This study also indicates that misconduct by police officers in the Nelson Mandela Bay area is not high. While whistle-blowing is considered as a key tool in promoting individual responsibility and accountability among police officers. In conclusion, recommendations are provided which could assist the SAPS and individual police officers to improve ethical conduct, and for improved measures and mechanisms to deal with unethical behaviour of police officers and recommendations for improved implementation of whistle-blowing process

Development of Kabila rocket: A radioisotope heated thermionic plasma rocket engine

AbstractA new type of plasma rocket engine, the Kabila rocket, using a radioisotope heated thermionic heating chamber instead of a conventional combustion chamber or catalyst bed is introduced and it achieves specific impulses similar to the ones of conventional solid and bipropellant rockets. Curium-244 is chosen as a radioisotope heat source and a thermal reductive layer is also used to obtain precise thermionic emissions. The self-sufficiency principle is applied by simultaneously heating up the emitting material with the radioisotope decay heat and by powering the different valves of the plasma rocket engine with the same radioisotope decay heat using a radioisotope thermoelectric generator. This rocket engine is then benchmarked against a 1N hydrazine thruster configuration operated on one of the Pleiades-HR-1 constellation spacecraft. A maximal specific impulse and power saving of respectively 529s and 32% are achieved with helium as propellant. Its advantages are its power saving capability, high specific impulses and simultaneous ease of storage and restart. It can however be extremely voluminous and potentially hazardous. The Kabila rocket is found to bring great benefits to the existing spacecraft and further research should optimize its geometric characteristics and investigate the physical principals of its operation

Ligands imidazolo et cyclopropenio phosphines : chimie de coordination, réactivité et applications en catalyse de vinylation vs allylation

The first part of the work thesis concerns the synthesis of heterocycles with an azo (N2) pattern based on a pallado-catalyzed key step. It has been shown that two families of dinitrogen heterocycles were selectively accessible from the same precursors, namely C-homo-allylic hydrazones. Mono-unsaturated five-membered rings pyrazolines or six-membered tetrahydropyridazines were thus prepared by N-vinylation or N-allylation through CH-oxidative intramolecular reaction catalyzed by palladium(II) complexes with phosphine ligands. It was shown that the outcome of the process depends on the basicity of the ionic ligands (of type X) of the palladium(II) salt precursor of the catalytic species. The use of Pd(OAc)2 was thus found to promote the formation of 6-methylidene-1,4,5,6-tetrahydropyridazines via a 6-endo/exo-trig process, while a more electrophilic complex [Pd(MeCN)2X2]; X = OTs, OTf, lead to 5-vinylpyrazolines via a 5-exo trig process. The particular efficiency of weakly donating ligands such as the imidazolophosphine "BIPHIMIP" has been highlighted here. The obtained 5-vinylpyrazolines and 1,4,5,6-tetrahydropyridazines were then selectively derivatized to their respective aromatic analogues, namely 5-vinylpyrazoles and 6-methylpyridazines, through a sequential isomerization-elimination process. Application of this synthesis method to di- and tri- C-homo-allylic hydrazone substrated allowed access to tri- or tetra-aromatic systems, in particular to poly-pyridazine analogues of terphenyls or triphenylbenzenes whose absorption and fluorescence properties have been systematically studied. The second part of the thesis is focused on the study of novel phosphorus ligands with "extreme" donor character. In particular, imidazolo- and cyclopropenio-phosphine ligands with a particularly weak donor character have been synthetized. In the neutral series, mono-, di- and tri-imidazolophosphines have been characterized and used in catalysis of allylic C-H bond functionalisation for the preparation of azo-heterocycles described in the first part. In the cationic series, two types of cyclopropeniophosphines were prepared: the bis-diisopropylamino-cyclopropenio(hydroxymethyl) phosphines and the bis-diisopropylamino-(dicyclopropenio)phosphines, obtained by reaction of a dichlorophosphine with a free carbene of the cyclopropenylidene type. The reactivity and coordination chemistry of the latter cationic ligands with transition metals (Pd, Rh, Au, Cu) were then studied. In the bis-diisopropylamino(dicyclopropenio)-P-tert-butyl series, a dicationic tetranuclear complex of palladium with two phosphido ligands was isolated. The elimination of the P-tert-butyl substituent was attributed to a strong electrostatic constraint within the complex. Finally, when trying to access novel electron-rich phosphonium ylides C-substituted by a cyclopropenyl moiety, an original rearrangement was observed. Vinylphosphoniums C-substituted by a four-membered heterocycle of the azetidine type have thus been obtained and fully characterized.La première partie des travaux présentés dans ce mémoire concerne la synthèse d'hétérocycles à motifs azo (N2) fondée sur une étape clef pallado-catalysée. Il a ainsi été démontré que deux familles d'hétérocycles diazotés étaient sélectivement accessibles à partir de précurseurs communs : des hydrazones C-homo-allyliques. Des cycles mono-insaturés à cinq chaînons de type pyrazoline ou à six chaînons de type tétrahydropyridazine ont été ainsi préparés par réaction de N-vinylation ou N-allylation CH-oxydante intramoléculaire catalysée par des complexes de palladium(II) à ligands phosphines. Il a été montré que l'issue du processus est fonction de la basicité des ligands ioniques (de type X) du sel de palladium(II) précurseur de l'espèce catalytique. L'utilisation de Pd(OAc)2 favorise ainsi la formation de 6-methylidène-1,4,5,6-tétrahydropyridazines via un processus 6-endo/exo trig, alors qu'un complexe plus électrophile [Pd(MeCN)2]X2; X = OTs, OTf conduit aux 5-vinylpyrazolines suivant un processus 5-exo trig. L'efficacité particulière des ligands faiblement donneurs tels que l'imidazolophosphine " BIPHIMIP " a été ici mis en évidence. Les 5-vinylpyrazolines et les 1,4,5,6-tétrahydropyridazines obtenues ont ensuite été sélectivement transformées en leurs dérivés aromatiques respectifs, à savoir des 5-vinylpyrazoles et 6-méthylpyridazines, selon un processus d'isomérisation-élimination séquentiel. L'application de cette méthode de synthèse à des substrats di- et tri-hydrazones C-homo-allyliques a permis d'accéder à des systèmes tri- ou tétra-aromatiques, en particulier à des pyridazylbenzènes analogues des terphényles ou triphénylbenzènes dont les propriétés électroniques d'absorption et de fluorescence ont été systématiquement étudiées. La deuxième partie de ce mémoire est consacrée à l'étude de nouveaux ligands phosphorés à caractère donneur " extrême " tels que des ligands imidazolo- et cyclopropénio-phosphines à caractère donneur particulièrement faible. En série neutre, des ligands mono-, di- et tri-imidazolophosphines ont ainsi été caractérisés et utilisés en catalyse de fonctionnalisation de liaisons CH allyliques pour la préparation d'azo-hétérocycles décrite dans la 1ère partie. En série cationique, des cyclopropéniophosphines de deux types ont été préparées : des bis-diisopropylamino-cyclopropénio(hydroxy)phosphines et des bis-diisopropylamino(dicyclopropénio)phosphines, obtenues par réactions d'une dichloro-phosphine avec un carbène libre de type cyclopropénylidène. La réactivité et la chimie de coordination avec des métaux de transition (Pd, Rh, Au, Cu, Pt) de ces ligands cationiques a été ensuite étudiée. En série bis-diisopropylamino(dicyclopropénio)-P-ter-butyle, un complexe tétranucléaire de palladium dicationique comportant deux ligands phosphido a été isolé. L'élimination du P-substituant ter-butyle a été attribuée à une forte contrainte électrostatique présente au sein du complexe. Enfin, lors de la tentative d'accès à de nouveaux ylures de phosphonium C-substitués par un motif cyclopropényle, un réarrangement original a été observé. Des vinylphosphoniums C-substitués par un hétérocycle à quatre chaînons de type azétidine ont été ainsi obtenus et entièrement caractérisés

An investigation into the use of whistle-blowing as a means to curb unethical behaviour of police officers in the Nelson Mandela Bay

The use of whistle-blowing as means to curb unethical behaviour of police officers in the Nelson Mandela Bay is investigated in this study. In order to investigate this, various instruments were used, these are interviews and questionnaires. However the objectives of the study were: - To examine the implementation of whistle-blowing in the SAPS. - To develop strategies and measures that can be used to encourage whistle-blowing in the SAPS. Broadly speaking, these objectives have been achieved by providing empirical evidence which shows that: - Unethical behaviour by police officers is the most ethical challenge facing police officers in the Nelson Mandela Bay Area. This is based on the findings which eminate from the interviews. - Whistle-blowing is used by police officers as an early warning system that alerts the superiors about misconduct before it is too late as it defects and deters wrongdoing. However, the study suggests various strategies and measures to assist the implementation of whistle-blowing. These strategies include: - Development of hotlines. - Assurance of confidentiality and anonymity of disclosures. - Response plan development. - Training development. - Regarding whistle-blowing as an ongoing communication. This study also indicates that misconduct by police officers in the Nelson Mandela Bay area is not high. While whistle-blowing is considered as a key tool in promoting individual responsibility and accountability among police officers. In conclusion, recommendations are provided which could assist the SAPS and individual police officers to improve ethical conduct, and for improved measures and mechanisms to deal with unethical behaviour of police officers and recommendations for improved implementation of whistle-blowing process

Transition-Metal-Free α-Vinylation of Enolizable Ketones with β-Bromostyrenes

An a-vinylation of enolizable ketones has been developed by using b-bromostyrenes and a KOtBu/NMP system. β,γ-Unsaturated ketones of E configuration were obtained in excellent yield and selectivity. Further synthetic possibilities are highlighted by one-pot functionalization via trapping of intermediate dienolates with alkyl, allyl, benzyl, and propargyl halidesto generate quaternary centers. The reported transformation is believed to proceed via phenylacetylene and propargylic alcohol intermediates

Filling a niche in “ligand space” with bulky, electron-poor phosphorus (III) alkoxides

The chemistry of phosphorus(III) ligands, which are of key importance in coordination chemistry, organometallic chemistry and catalysis, is dominated by relatively electron-rich species. Many of the electron-poor P(III) ligands that are readily available have relatively small steric profiles. As such, there is a significant gap in “ligand space” where more sterically bulky, electron-poor P(III) ligands are needed. This contribution discusses the coordination chemistry, steric and electronic properties of P(III) ligands bearing highly fluorinated alkoxide groups of the general form PRn(ORF)3-n, where R = Ph, RF = C(H)(CF3)2 and C(CF3)3; n = 1-3. These ligands are simple to synthesize and a range of experimental and theoretical methods suggest that their steric and electronic properties can be “tuned” by modification of their substituents, making them excellent candidates for large, electron-poor ligands

Mossendjo: l'organisation de l'espace par une petite ville congolaise du Chaillu forestier

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe