Text in English / This dissertation examines the missionary activities of Rev. J.L.R. Rammala of the Uniting Reformed Church in Southern Africa (URCSA) which was formally called the Dutch Reformed Church in Africa (DRCA). Rev. Rammala worked among the Bushmen (San) of Botswana as a missionary from 1973 to 1980. The study examines how the DRCA as a·· product of Western missions, developed its own understanding of mission when judged through the mission activities of Rev. Rammala in Botswana as a case study. This understanding of mission is judged against the background of the survey of the debate on Third World missions, and the DRCA's involvement in intercultural mission. / Christian Spirituality, Church History and Missiology / Th. M. (Missiology)

Text in English / This dissertation examines the missionary activities of Rev. J.L.R. Rammala of the Uniting Reformed Church in Southern Africa (URCSA) which was formally called the Dutch Reformed Church in Africa (DRCA). Rev. Rammala worked among the Bushmen (San) of Botswana as a missionary from 1973 to 1980. The study examines how the DRCA as a·· product of Western missions, developed its own understanding of mission when judged through the mission activities of Rev. Rammala in Botswana as a case study. This understanding of mission is judged against the background of the survey of the debate on Third World missions, and the DRCA's involvement in intercultural mission. / Christian Spirituality, Church History and Missiology / Th. M. (Missiology)

This Bachelor thesis has been written at the Blekinge Institute of Technology. This thesis concentrates on the wind power and their components, also the large wind farm is studied. The electrical power is generated by using the power in wind to drive a wind turbine to produce mechanical power. This mechanical power can be converted into electrical power by using electrical induction generators. There are two types of the wind turbines, the horizontal axis and vertical axis wind turbine, where the horizontal axis wind turbine is mostly used and was studied in this thesis. The rotor can be placed in two directions: an upwind rotor where the blade of turbine faces to the wind, so it operates more smoothly and transmit more power. The other type is a downwind rotor which orients itself with respect for the wind direction. Moreover, the tower shadow makes the blade to flex, consequently resulting in fatigue, noise, and reduces output of the power. The modern wind turbine has been built with an odd number of blades which is important for the stability of the turbine. The rotor with an odd number of blades can be considered to be similar to a disc when calculating the dynamic properties of the machine. The main idea of this thesis is to study the wind power in general and large wind parks specifically. The Horns Rev wind park was taken as an example of a wind park in Denmark and the Gotland wind park as an example of a wind park in Sweden too. Into account, the distance between wind turbine in the wind direction cannot be too small. If the wind turbines are located to close to each other, the wind will be more and more turbulent after it passes through each single wind turbine. This would lead to that wind turbines downstream in the wind park, and it might even have to shut down due to that mechanical loading gets to high during strong conditions. This is due to the fact that when wind passes through the rotor of the wind turbine it gets very turbulent and the wind speed is decreased. The minimum length of the rotor should be approximately 5-7 rotor diameters to avoid that issue. Gotland Energy AB (GEAB) considered, that high voltage direct current light would be the only realistic way to solve the technical problems for the high amount of wind power in-feed. One result is that The stability of voltage during transient events, has become much better by using the high voltage direct current light so that the output current stability from the asynchronous generators have been improved, which reduces the stresses on the AC grid and on the mechanical construction of the windmills. / In general the wind turbines with three blades accommodated a thicker root are used. It is obvious that, the less number of blades on the wind turbine, the cost of material and manufacturing will be lower. It is worthy to mentioned that, the modern wind turbine has been built with an odd number of blades. When the length of the blade increases the deflection of blade tip due to axial wind force also increase as well. So without consider the increase in length of blade may lead to dangerous situation of collision of tower and blade. Moreover, by increasing the number of blades cost of the system would increased as well. The limit of transfer for the AC transmission system depends on the distance from shore and is therefore physically limited by this. AC large wind parks that are placed at a long distance from the shore, which means AC long transmission line, and more drop voltage A solution to AC long transmission line, it could be to decrease the offshore frequency and use a low frequency AC networks. There is a suggestion by for instance (Schütte, Gustavsson and Ström 2011). The usages of a low frequency system are in electrified railway systems, where the frequency ranges from 16.67 Hz to 25 Hz. However, the network of a low frequency would allow a simpler design of the offshore WTs and The aerodynamic rotor of a large WT operates at maximum revolutions at 15-20 rpm. The lower frequency would then allow a smaller gear ratio for turbines with a gearbox, or decrease the poles number for WTs with direct driven generators. This would lead to lighter and cheaper turbines. One of the disadvantages by using a low frequency system is the size of transformer would be increased, and hence, the costs of transformer will increased too. The operator of the grid, Gotland Energy AB (GEAB) considered, that HVDC light would be the only realistic way to solve the technical problems for the high amount of wind power in-feed. The experiences have supported expected improvements in the characteristics for example: - Stability in the system arose. - Reactive demands, power flows, as well as voltage level in the harmonic and system were reduced. - Flicker problems were eliminated with the installation of HVDC light and transient phenomena disappeared. Moreover, Overall experiences of Gotland Energy AB (GEAB) are that the control of power flow from the converters makes the AC grid easier to observe than a conventional AC network and the power variations do not stress the AC grid as much as in normal network. Voltage quality has been better with the increased wind power production. A topic to study in the future is the consequences of blackouts in power supply with many wind power farm. / 004676396018

A MATTER OF NATIONAL CONCERN examines the Kennedy Administration’s contribution to the restoration of public education in Prince Edward County, Virginia, and determines if those actions support the dominant narrative of Kennedy’s overall civil rights record – a historical assessment generally generated from a few acute crises. For five consecutive years (1959-1964), in defiance of federal court orders, the county board of supervisors refused to levy taxes to operate public schools, marking Prince Edward County as the only locale in the nation without free public education. The county leadership organized a segregated private school system for the 1,400 white children, but afforded no formal education for the 1,700 African American students. The Kennedy Administration inherited the Prince Edward County school situation – a crisis that threatened to cripple a generation, and, if replicated, destroy public education. In the Prince Edward County school dilemma, the Kennedy Administration took proactive measures, proved sympathetic to the plight of African Americans, challenged Virginia’s congressional delegation, and appointed federal judges that supported President Kennedy’s civil rights agenda. The Prince Edward County story generally, and the federal government’s actions specifically, have been virtually overlooked by historians. A MATTER OF NATIONAL CONCERN challenges scholars to re-evaluate the Kennedy Administration’s civil rights record by including all of the civil rights events of the Kennedy years, thus developing a thorough, comprehensive assessment. A MATTER OF NATIONAL CONCERN is the product of the study of unpublished archival documents, oral histories, interviews, newspaper reports, and secondary sources. This work was created using Microsoft Word 2003.