Testing of Transformer Differential Protection

Cílem bakalářské práce bylo chránění transformátoru, konkrétně pak rozdílová ochrana transformátoru, její princip funkce, stabilizace a vypínací charakteristika. Byl navrhnut způsob měření vypínací charakteristiky ochrany SPAD 346 C od firmy ABB. K měření bylo použito testovací zařízení TZO3, které bylo stejně jako testovaná ochrana nastavováno počítačem, do kterého byli také následně ukládány výsledky jednotlivých měření. Testování bylo provedeno zkouškou typu „TREND“ pro tři různá nastavení vypínací charakteristiky ochrany a zároveň bylo každé nastavení proměřeno pro dvě různé strmosti trendové zkoušky. Byly nastaveny dvě mezní vypínací charakteristiky a třetí charakteristika byla nastavena přibližně doprostřed mezi dvě mezní nastavení. Byl ukázán výpočet chyby měření. A protože byly použity dvě strmosti trendové zkoušky, byl také proveden přibližný výpočet reakční doby ochrany. Všechny naměřené a vypočtené hodnoty byly vyneseny do grafů, z kterých byl vidět rozdíl v jednotlivých měřeních. Také byly vysvětleny a spočítány možnosti eliminace nárůstu proudu během reakční doby ochrany při strmějším růstu trendové zkoušky.My bachelor thesis deals with the protection of a transformer, the main focus of the thesis is the differential protection of a transformer, the principle of its function, stabilization and the operating characteristic. I suggested a way of measuring the operating characteristic of the protection SPAD 346 C (developed) by ABB company. As far as measurement is concerned, I used the testing device TZO3, which was, as well as the tested protection, configurated by a computer, into which the results of single measurements were put. The testing was performed via a kind of a test known as ,,TREND“ test for 3 various configurations of operating characteristic of protection and each measurement was scaled for 2 different ,,TREND“ testings. Two marginal operating characteristics were configurated and the third characteritic was configurated approximately between 2 marginal configurations . An error in the calculations of measurement was shown. Since there were two ,,TREND“ tests of steepness performed, there was a calculation of reaction time of protection conducted/performed as well.. All measured and calculated data were processed to graphs in order to illustrate differences among single measurements. I also provided explanations and calculations of possibilities of elimination of increase of electric current within reaction time of protection at steeper increase of ,,TREND“ test.

Semiologia da anca: considerações gerais

As afeções da anca ocupam um lugar de destaque na Patologia Clínica pela sua elevada frequência e pelas repercussões funcionais que podem originar. Salientam-se os achados semiológicos conseguidos através da anamnese rigorosa e de um exame físico, no sentido de representarem os pilares angulares no diagnóstico de uma afeção da anca. Tudo começa com eles e todas as conclusões devem passar por eles. Por seu turno e em complemento, os exames laboratoriais, de imagem e anatomopatológico podem permitir o diagnóstico definitivo e, desta forma, tornar-se possível oferecer ao doente o melhor tratamento. Num grande número de situações, a avaliação clínica complementada por um exame radiológico da anca permitem chegar a um diagnóstico definitivo

Artrite Reumatóide: o ponto de vista do ortopedista

O tratamento da artrite reumatóide assenta no trabalho de uma equipa multidisciplinar constituída por reumatologistas, ortopedistas, fisiatras e anestesistas, entre outros. A intervenção cirúrgica representa, apenas, uma das etapas da planificação do tratamento global do doente. A cirurgia na artrite reumatóide deve ser reservada para os doentes que não respondam satisfatoriamente a um tratamento médico bem conduzido, e deve ser efectuada, de um modo geral, nos estádios iniciais da doença, por forma a permitir alcançar o melhor resultado. Se assim não acontecer, se o doente não for operado em tempo útil, estabelecem-se lesões das partes moles irreversíveis, cujo tratamento conduz, naturalmente, a um resultado menos conseguido, apesar das modalidades cirúrgicas de elevada eficácia terapêutica que actualmente dispomos. Com a cirurgia pretende-se, de um modo geral e numa ordem de prioridades decrescentes, aliviar/suprimir a dor, melhorar a função, prevenir as destruições, corrigir as deformidades e melhorar a estética. O objectivo final a conseguir é a reintegração sócio-profissional do doente, nas melhores condições que for possível. A determinação das prioridades cirúrgicas é um problema específico da artrite reumatóide. A decisão de onde, quando e que tipo de operação cirúrgica deve ser realizada em primeiro lugar, pode constituir a parte mais delicada da abordagem terapêutica

Tłįcho˛ stories for Ekwò˛ management

This paper is adapted from contributions to the NACW Aboriginal Talking Circles, as well as the author’s contributions to two co-authored presentations: “Using dual knowledge systems to inform management decisions: a Wek’èezhìı Renewable Resources Board example,” with Jody Snortland; and “Monitoring Caribou and People,” with Allice Legat and John B. Zoe

Aloenxertos criopreservados no tratamento de defeitos osteocartilagíneos

A reparação cirúrgica dos defeitos da cartilagem articular representa uma das situações mais difíceis de tratar em Ortopedia. Os aloenxertos osteocartilagíneos devem ser reservados para a reconstrução de defeitos significativos envolvendo cartilagem e osso (> 3 cm de diâmetro e 1 cm de profundidade), isto é, nas lesões demasiado extensas para serem corrigidas através de outras técnicas. Os aloenxertos osteocartilagíneos criopreservados apresentam vantagens em relação aos frescos, que incluem uma maior segurança microbiológica, menor capacidade imunogénica ligada ao tecido ósseo e estão disponíveis em maior número. No entanto, os aloenxertos osteocartilagíneos frescos mantêm uma maior viabilidade condrocitária e, por isso, oferecem um melhor desempenho clínico. Embora permita recuperar um maior número de condrócitos vivos, a utilização de crioprotectores está ainda longe de originar a protecção completa e eficaz de todos os condrócitos presentes na cartilagem articular, o que compromete significativamente o desempenho clínico a médio ou a longo termo dos aloenxertos osteocartilagíneos criopreservados. A combinação de um potente agente crioprotector como parece ser a arbutina, com meios mecânicos capazes de exercer uma pressão adequada poderá ser a chave para se alcançar uma percentagem significativa de condrócitos vivos após o processo de descongelação da cartilagem criopreservada e, assim, poderá assegurar a eficácia clínica, a médio e longo prazos, dos aloenxertos osteocartilagíneos criopreservados

Examining bureaucratic performance of South African local government: local municipalities in Limpopo province

A thesis submitted in fulfillment of the requirements for the degree of Doctor of Philosophy (Public Management) at Wits school of governance Faculty of Commerce, Law and Management University of the Witwatersrand South Africa 2016In democratic South Africa, power regarding the provision of public goods and services is decentralised to local government level simply because municipalities are the coalface of service delivery and are closer to the people than national and provincial spheres of government. As a result, municipalities are assigned service delivery responsibilities by the Constitution. To discharge these constitutional responsibilities and functions in terms of public goods and service provision effectively and efficiently, municipalities are, firstly, expected to have high institutional capacity to deliver and be held accountable to their municipal councils and to behave in a fiscally responsible manner. Secondly, they are further expected to be characterised by strong and powerful municipal councils to exercise their formal powers of oversight function over municipal administration. Despite huge and continuous resource investment in terms of funding and capacity building and training interventions from the centre to build and strengthen the local government capacity to fulfil its public goods and service delivery responsibilities, South African local government, with specific reference to Limpopo local government, continues to be afflicted by persistent poor bureaucratic performance in relation to water and sanitation provision as well as financial management. In Limpopo Province, there are, however, a very few pockets of good performance (e.g. the Waterberg District Municipality) pertaining to financial management. Generally, manifestation of these governance problems is illustrated by high rates of negative audit outcomes, high levels of underspending, high levels of financial misconduct, high consumer debt and increasing sporadic community protests against poor municipal service delivery. Using a qualitative research approach and methods (i.e. interviews, observations, focus group discussions, questionnaire and document review), this study has explored the determinants of bureaucratic performance of South Africa’s local government with specific reference to Limpopo local government. A multiple qualitative case study approach, consisting of five municipalities (i.e. Capricorn and Waterberg District Municipalities, and Fetakgomo, Greater Tubatse and Greater Tzaneen Local Municipalities) was, thus, applied. This multiple case study approach assisted in enhancing the validity and reliability as well as replication of the study results to the entire system of Limpopo local government. Both purposive and random sampling techniques were used to sample the above mentioned five case studies and select the research participants. The added value of this study is, of course, the new dimension it has suggested such as theory of bureaucracy and the principal-agent model to explore and analyse the determinants of municipal bureaucratic performance in Limpopo Province. In effect, these two theories have rarely been tested together in analysing local government bureaucratic performance, but, in this study, they are used together to analyse the phenomena. In spite of their commonalities and variations, the study has discovered that not all bureaucratic performance failures within Limpopo local government are related to the lack of meritocracy, especially at managerial level. In effect, the level of meritocracy is very low at operational and implementation level in municipalities. The study, for example, has found that the percentage of the total municipal workforce with university or college qualifications at National Qualification Framework level 6 and above stood at 17 percent in the Greater Tubatse Municipality as compared to 58 percent and 76 percent in Fetakgomo and Greater Tzaneen Local Municipalities respectively. At the management level, the study, in contrast, found that the percentage of senior managers with professional qualifications at NQF level 6 and above stood at more than 80 percent in all the above-mentioned local municipalities. At the district level, the study further found that the percentage of total municipal workforce with university qualifications at NQF level 6 and above, as prescribed by municipal regulations on minimum competency level requirements and qualifications, stood at 7.4 percent and 59 percent respectively in the Capricorn and Waterberg District Municipalities in the period the study was undertaken. The study, however, has revealed serious paradoxes at management level regarding the possession of university qualifications by senior managers. For instance, the study found that the percentage of section 54A and 56 managers with professional qualifications at NQF level 6 and above in the Waterberg District Municipality was 86 percent as opposed to 33.3 percent in the Capricorn District Municipality. On the matter of the municipal council oversight function over municipal administration, the study findings confirmed the initial study proposition that strong and independent municipal councils, as opposed to weak or less-independent councils, play a vital role in determining bureaucratic quality or performance of municipalities. In effect, the study found that municipal councils or their council oversight committees in selected case studies were ineffective in exercising their formal powers of oversight. According to the study, the ineffectiveness of municipal council oversight committees was attributed to the following; institutional instability that characterised these municipalities between 2011 and 2014; the influence of political parties; or the prolonged and sustained single dominance of the municipal councils by one political party. Given the parliamentary governance system generally adopted by the South African state, the study further observed that municipal councils are effectively rendered inefficient by the fusion of both legislative and executive powers in the same person, being the municipal council. In contrast, this is, however, not the case in national and provincial spheres of government where the separation of powers between the legislature and the executive is clear and unambiguous compared with the local sphere of government. The study concluded that the persistent poor bureaucratic performance of South African local government, with specific reference to Limpopo local government, is as a result of none institutionalisation and none enforcement of a meritocratic recruitment culture at operational and implementation level as opposed to that at a management level. In addition, weak and less-independent municipal councils account for persistent poor bureaucratic performance of municipalities in Limpopo Province. If Limpopo local government is to become more developmental and meet the minimum service delivery expectations of communities, the study suggests that institutionalisation of meritocracy must be enforced by well-resourced and independent municipal councils vis-a-vis mayoral executive committees.MT 201

An examination of the perceptions of the importance and effectiveness of delivery of the North Central Association program functions to Iowa schools

Purposes of this study were to determine among Iowa schools the mean levels of importance and effectiveness of delivery of the four NCA program functions, value of NCA membership to the communities, preferred format for evaluation, intent of individuals to continue NCA membership; and to determine whether relationships exist between the above factors and selected demographic role factors;All Iowa NCA member schools and a stratified random sample of Iowa NCA non-member schools were surveyed by mail. The survey included questions related to demographic role factors and a five-point Likert-type scale on NCA benefits were grouped into four NCA program functions. Member schools attached value to the importance and effectiveness of delivery of NCA\u27s program functions. Non-member schools attached value to importance only;Descriptive statistics and chi square goodness of fit tested the relationships among demographic and role factors, future NCA membership, and the value of NCA membership to the community. Analysis of variance and repeat-measure analyzed differences in the mean levels of importance and effectiveness of delivery when categorized by selected factors;Research findings reveal that NCA\u27s direction aligns with functions perceived to be most important by Iowa schools. However, NCA is delivering the functions at a lower level. Differences in the mean levels of importance were significant within program functions when categorized by district enrollment and the respondent\u27s role among Iowa member schools;An individual\u27s perception of the value of NCA to the community increases with the mean levels of importance and effectiveness of delivery attached to NCA\u27s program function in addition to the individual\u27s prediction of future NCA membership. Only three-fourths of Iowa member and non-member schools and one fifth of Iowa non-member schools predict future NCA membership. Their prediction is more positive as their levels of importance and effectiveness of delivery and their perception of the value of NCA membership to the community become more positive;The traditional format for evaluation is only used by half the respondents from Iowa member schools. However, its use is being replaced by the OUTCOMES and ALTERNATIVE formats

Fabrication and characterization of high current-density, submicron, NbN/MgO/NbN tunnel junctions

At near-millimeter wavelengths, heterodyne receivers based on SIS tunnel junctions are the most sensitive available. However, in order to scale these results to submillimeter wavelengths, certain device properties should be scaled. The tunnel-junction's current density should be increased to reduce the RC product. The device's area should be reduced to efficiently couple power from the antenna to the mixer. Finally, the superconductor used should have a large energy gap to minimize RF losses. Most SIS mixers use Nb or Pb-alloy tunnel junctions; the gap frequency for these materials is approximately 725 GHz. Above the gap frequency, these materials exhibit losses similar to those in a normal metal. The gap frequency in NbN films is as-large-as 1440 GHz. Therefore, we have developed a process to fabricate small area (down to 0.13 sq microns), high current density, NbN/MgO/NbN tunnel junctions