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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Igoru music in Okpeland : a study of its fuctions and compositional techniques

Idamoyibo, Ovaborhene Isaac 19 January 2007 (has links)
This study focused on the functions of Igoru music in Okpe land. It also examined the compositional techniques of the music typology. The primary source for data collection was oral interview. Secondary sources include publications, and records. Unstructured research questions formed basis for the study. The texts of eighty seven (87) songs were transcribed and translated for this study. Fifty songs from this sample were further transcribed in staff notation, for analysis and discussion. At the end of the study, the following findings were made: <ul> <li>Igoru musicians, in their foresight, investigate, evaluate, probe, counsel, warn, and foretell future events in Okpe, to avoid painful experiences, since in traditional Okpe society, life experiences are shared.</li> <li>Most of the themes in Igoru music are derived from the sense of realism than idealism. The songs being quite topical had to be realistic than idealistic in tendency. Various sound and speech elements are put together to make communication effective. </li> <li>Igoru music praises and commends deserving members, in order to encourage those who are doing well in the society to continue in their good deeds, as well as stimulate others to emulate them.</li> <li>The musicians defend their political system, their territorial land mass, traditional religion and themselves from various attacks.</li> <li>Igoru music represents the Okpe identity, thus it was selected amongst other music typologies of the culture to represent it, both in social and political-oriented activities in Lagos and elsewhere.</li> <li>Igoru music uses the hexatonic scale system. Almost all the songs were found to be composed in compound quadruple metre. The performers involve in two-part polyphonic singing. Consecutive parallel 3rds, 4ths, and 5ths are prevalent and melodic cadences resolve upwards than downwards. Shifts of tonal centre (key), according to the convenience of performers, as well as recycling of themes are also common features. </li></ul> / Thesis (Doctor of Music (DMus))--University of Pretoria, 2007. / Music / unrestricted
112

A synergy between well-defined homogeneous and heterogeneous catalysts : the case of Ring Opening - Ring Closing Metathesis of cyclooctene / Une synergie entre des catalyseurs hétérogènes ou homogènes bien définis : application à la réaction tandem d’ouverture et de fermeture de cycle par métathèse (RO-RCM) du cyclo-octène

Kavitake, Santosh 14 October 2011 (has links)
Dans le cadre de la formation sélective d'oligomères cycliques à partir du cyclo-octène, des matériaux hybrides organiques-inorganiques mésostructurés bien-définis contenant les unités Ru-NHC dissymétriques le long des canaux poreux de leur matrice de silice ont été développés et caractérisés à un niveau moléculaire. Tous les systèmes obtenus ont montré des fortes activités et sélectivités en oligomères cycliques (dimères : 50% et trimères : 25%) en RO-RCM du cyclo-octène, contrairement aux complexes homogènes Ru-NHC analogues symétriques (G-II et GH-II), qui conduisent préférentiellement à la formation de polymères. La variation de la longueur et de la flexibilité des bras espaceurs, dans le cas des catalyseurs hétérogènes, a prouvé que les bras courts et flexibles stabilisent grandement les sites actifs Ru-NHC pendant la réaction de métathèse et ce, grâce à la présence d'interactions entre les sites Ru-NHC catalytiquement actifs et la surface silicique. La présence de telles interactions a été mise en évidence par RMN du phosphore 31 à l'état solide. Des études supplémentaires concernant les performances catalytiques de complexes organométalliques Ru-NHC dissymétriques (analogues aux sites Ru-NHC contenus dans les catalyseurs hétérogènes) et Ru-NHC symétriques (G-II et Nolan) ont clairement montré que le facteur clé influençant la sélectivité en oligomères cycliques est la dissymétrie des ligands NHC. Cette dissymétrie génère la présence de deux sites actifs de configurations différentes au sein même des espèces Ru-NHC. Un des sites favorise la réaction intramoléculaire de fermeture de cycle par métathèse alors que l'autre site permet la réaction intermoléculaire d'ouverture de cycle conduisant ainsi à la formation des oligomères cycliques de petite taille / In the context of the selective formation of cyclic oligomers from cyclooctene, well-defined hybrid organic-inorganic mesoporous materials containing unsymmetrical Ru-NHC units along the pore channel of their silica matrix have been developed and characterized at a molecular level. All systems displayed high activity and selectivity towards the formation of lower cyclic oligomers in the RO-RCM of cyclooctene yielding mainly the dimer and the trimer with 50% and 25% selectivity, respectively, in contrast to classical symmetrical homogeneous analogues (G-II and GH-II), which yield mainly to polymers. Variation of length and flexibility of the tethers showed that flexible short tethers were critical for high stability of the catalysts during metathesis, which is consistent with the stabilization of Ru-NHC active sites by surface functionalities; this surface interaction was further corroborated by the absence of a PCy3 ligand coordinated to Ru when short flexible linkers are used. Further investigations using homogeneous symmetrical (G-II and Nolan) and unsymmetrical (analogues to heterogeneous catalysts) Ru-NHC catalysts clearly showed that the key factor influencing the selectivity towards low cyclic oligomers is the unsymmetrical nature of NHC ligands, which creates dual site configuration in the catalyst architecture thus alternatively favouring one reaction over another, Ring Opening (ROM) vs. Ring Closing (RCM) Metathesis (propagation vs. backbiting), thus leading to the selective tandem RO RCM of cyclooctene. Finally, we have also investigated Grubbs Hoveyda-II (GH-II) type catalysts immobilized on silica support through adsorption, which showed the same product selectivity as that of the well-defined Ru-NHC materials. This result implies that the adsorbed symmetrical GH-II catalyst “becomes unsymmetrical upon adsorption”. Adsorbing unsymmetrical molecular GH II catalysts did not however improve the performances of these types of catalysts. Overall, the unique property of unsymmetrical NHC Ru catalyst, whether supported or not, opens new perspectives in the selective synthesis of macrocycles from other cyclic alkenes via metathesis
113

Développement de nouveaux outils de contrôle conformationnel utilisant des interactions non-covalentes pour effectuer des macrocyclisations

Bolduc, Philippe 11 1900 (has links)
No description available.
114

Synthèse et évaluations biologiques de strigolactones, nouvelle classe d'hormones végétales / Synthesis and biological evaluations of strigotactones, a new class of plant hormones

Chen, Victor 20 July 2011 (has links)
Ce travail de thèse présente la mise au point d’une nouvelle stratégie de synthèse en vue de l’obtention d’analogues des strigolactones, apocaroténoïdes possédant de multiples activités biologiques d’intérêt agronomique : médiateurs chimiques intervenant dans la mise en place de la symbiose endomycorhizienne et nouvelle classe d’hormone végétale contrôlant l’architecture de la plante.La stratégie de synthèse est basée sur l’utilisation d’une séquence de deux réactions clefs qui sont une métathèse cyclisante d’oléfine (RCM) et une cyclisation radicalaire avec transfert d’atome catalysée par un métal de transition (ATRC). Tout d’abord, une synthèse rapide et efficace des précurseurs a été développée et après optimisation de la séquence RCM / ATRC, divers analogues fonctionnalisés en position C4 ont été obtenus après aménagements fonctionnels. D’autres bioisostères des strigolactones naturelles ont été synthétisés par variation au niveau du cycle C. En se basant sur la voie synthétique précédemment élaborée, la première synthèse asymétrique du Solanacol a été effectuée permettant la détermination de sa stéréochimie relative en C2’ et sa configuration absolue. L’évaluation des activités biologiques dans les différents modèles des composés synthétisés est aussi décrite. / This Ph.D. work has been centred on the elaboration of a new synthetic strategy in goal to obtain analogues of natural strigolactones, apocarotenoids with various biological activities of agronomic interests: chemical mediators implicated in the endomycorrhizal symbiosis and a new class of plant hormone controlling the plant architecture.The synthetic strategy is based on the sequence of two key reactions, which are ring closing metathesis (RCM) and atom transfer radical cyclisation (ATRC). First, a rapid and efficient access to the synthetic precursors has been developed and after optimisation of the RCM / ATRC sequence, several analogues functionnalised at the C4 position were obtained after judicious steps. Other bioisoters were obtained with variations on the C ring. On the basis of the elaborated synthetic pathway, the first asymmetric synthesis of Solanacol was successfully achieved conducting to the determination of the relative stereochemistry at C2’ position and its absolute configuration. The biological evaluations of the synthesized molecules in the different models were also described.
115

Laboratorní přípravek pro testování tranzistorů IGBT / Laboratory test equipment for IGBT transistors

Chvátlina, Pavel January 2009 (has links)
This master’s thesis describes the function and realization of the laboratory test equipment designed for measuring and analysing of collector current iC and voltage uCE courses during the opening and closing process of a power IGBT transistor. The opening and closing times toff and ton of the new power transistor IGBT are changing in the range from tenths to the ones s, so the reading of current iC and voltage uCE proceeds in a very short time. The measuring circuit of this test equipment is based on a short-time discharging of a condenser battery to the inductive load over the measured transistor. Consequently it is possible to replace the power supply whose maximum output power would otherwise have to be in the range of ones MW. In the final part of this thesis there are described properties and design of a high-frequency sensor with the Rogowski coil, which can be used for reading collector current course during opening and closing time of the measured transistor IGBT. Collector current iC and voltage uCE courses can be analysed with a storage oscilloscope.
116

Zdravotně technické instalace ve výrobním závodě / Sanitation installation in a factory

Gerych, Michal January 2014 (has links)
The Master´s thesis solves question about sanitation installations in factory in Přelouč. The theoretical part deals with pumping technique and pumping of wastewater. The work also focuses on possible solutions of the given specialization. The project part solves the sanitation installation of this factory in the selected variant. It is a large hall with administrative part.
117

Uzavírací mechanismus papírových sáčků / Closing mechanism paper bag

Klíma, Pavel January 2009 (has links)
This thesis deals with a design of new dot-wheels gearing. These wheels serve for closing of paper covers of tea bags. First of all the suggested spare options of the gearing shape are compared with the original. On the basis of the comparison results the gearing is solved as a substandard kind of involute gearing. The involute gearing is designed by the method of generalized parameters. For the gearing design the program GEARING – symetrical profile version 1.5. was used. Consequently this program was adapted for the case of the change of the instrument shape by the user. The kind of wheels material was designed. Further the way of wheels production for single-piece and batch production was also designed. At the end the economic evaluation of the wheels production with newly designed profile was done.
118

Ekonomický náhled volby rychlozávěrného ventilu pro vodní dílo Vranov / Economic view of the fast closing valve selection for HPP Vranov

Gipka, Ondřej January 2012 (has links)
The thesis deals with the evaluation of the investment in the fast closing valve replacement in The dam Vranov using Computational fluid dynamics (CFD). The final effects of the fast closing valve replacement will be examined on three different types of valves with regard to the turbine output in operation zone and without the influence of water intake runner and turbine draft tube. The aim of the thesis is to theoretically evaluate alternatives of the fast closing valve replacement and define its basic characteristics and classifications.
119

Oro och hopplöshet som konsekvens när skolpersonal beskriver elevers delaktighet : En studie om hur skolpersonal beskriver att elever görs delaktiga i en process där skolor stängs för att motverka skolsegregation

Campbell, My January 2021 (has links)
Denna studie syftar till att undersöka hur skolpersonal beskriver att elever görs delaktiga i en process där skolor stängs i syfte att motverka skolsegregation. Underliggande frågeställningar handlar också om hur skolpersonalen beskriver elevernas psykosociala situation och mer ingående hur elever mer konkret ges delaktighet och inflytande att påverka sin situation. Studien och analysen tar stöd i diskursteorin som syftar till att få syn på diskurser som ett specifikt sätt att tala om någonting inom en specifik sfär. Shiers (2001) modell om delaktighet finns också som stöd i analysarbetet. Studiens metod har varit fokusgruppsintervjuer med skolpersonal på de skolor som nu stängs.  I resultatet framkommer tre diskurser i relation till skolpersonalens tal om delaktighet och psykosociala situation. I relation till den psykosociala situationen framkommer ”avsaknad av ett sammanhang” som en diskurs. Att inte veta vart man ska, bristfällig information från ledningen och att inte accepteras i den nya miljön är artikulationer som skolpersonalen vittnar om. I relation till att elever beskrivs få inflytande och delaktighet framkommer både”hopplöshet” och ”förväntningar” som två diskurser av delaktighet. ”Hopplöshet” i relation till att eleverna inte ges inflytande på riktigt och ”förväntningar” i relation delaktighet i ett längre perspektiv. Att lära sig språket, se nya miljöer och möta andra är de aspekter som i förlängningen kan ge elever mer delaktighet i ett vidare perspektiv i livet. / This study aims to examine how school personnel describes that student are made involved in a process where schools are closed to counteract school’s segregation. Underlying issues are also about how the school personnel describes the psychosocial situation of the students and more in-depth how students are made more involved to influence their situation.  The study and the analysis take support in the theory of discourse and refer to see discourses as a specific way to speak of something within a specific sphere. Sheirs (2001) model about participation is also in the work of analysis as a support. The method of the study has been interviews with focus groups which is school personnel from the schools who now are shutting down.  In the result appears three discourses in relation to the school personnel’s speaking about participation and psychosocial situation. In relation to the psychosocial situation appears a"lack of context" as a discourse. Not knowing where to go, lack of information from the management and to not be accepted in the new environment are articulations as the school personnel testifies about. In relation to influence and participation appears both "hopelessness" and "expectations" as two discourses of participation. "Hopelessness" in relation to that the students are not being given influence for real and "expectations" in relation to participation in a longer perspective. To learn the language, see new environments and to meet others are the aspects that by extension could give students more participation ina broader perspective in life.
120

Oxford Rig Simulation for Analysis of the Effect of Posterior Tibial Slope Changes and Variable Ligament Stiffness on Knee Biomechanics

Geers, Katherine 27 October 2022 (has links)
No description available.

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