This thesis presents an observational study of molecular abundances in the dense cores of 27 prominent molecular clouds in the southern galactic plane.The molecular abundances and physical conditions in dense condensations have been derived from millimetre-wavelength observations of molecular rotational transitions.The study has produced a comprehensive data set of transition intensities and abundances for 10 different molecules in bright southern molecular clouds, and the general characteristics of emissions from these molecules such as optical depth, excitation and relative abundances are discussed. A comparison of different methods of calculating molecular hydrogen column density from observations of carbon monoxide emission is included.Both the analysis and the data collected provide an excellent starting point for further observational and theoretical studies of molecular clouds in the southern Milky Way utilising new instruments such as the millimeter-wave upgrade to the Australia Telescope Compact Array and the Attacama Large Millimetre Array (ALMA). / Doctor of Philosophy (PhD)

M. Tech. Architecture (Professional) / Over the last decade, South Africa (RSA) has experienced a substantial growth in the field of astronomy and astrophysics. Post 2005, the largest optical telescope in the Southern hemisphere, known by its acronym, SALT, was constructed in RSA. It is expected that by 2024, this country will host the largest array of radio telescopes in the world, the Square Kilometre Array (SKA). It could be argued that RSA is at the forefront of modern cosmological research. This exponential growth in the field of astronomy has resulted in local astronomical bodies and universities falling behind in astronomy education. This provides a unique opportunity to strengthen the latter. The aim of this dissertation is to design an International School of Astronomy and Astro-Tourism Centre. The proposed building aims to introduce a unique facility in the Northern Cape that would benefit the field of astronomy worldwide. The proposed facility is situated at the South African Astronomical Observatory (SAAO) in Sutherland. It is nested within the South-west-embankment of the mountain, currently hosting the Southern Africa Large Telescope (SALT). The resultant design takes on a linear building typology with radial aspects to document astronomical events. The project investigates the semi-arid Karoo climate and how the resultant architecture reacts to harsh environmental conditions.

The radio astronomy and space geodesy scientific instrumentation of the Hartebeesthoek Radio Astronomy Observatory (HartRAO) in Gauteng, South Africa, generate large volumes of data. Additional large data volumes will be generated by new geodesy instruments that are currently under construction and implementation, including a lunar laser ranging (LLR) system, seismic and meteorological systems and a Very Long Baseline Interferometry (VLBI) global observing system (VGOS) radio telescope. The existing HartRAO data management and storage system is outdated, incompatible and has limited storage capacity. This necessitates the design of a new geodetic research data management system (GRDMS). The focus of this dissertation is on providing a contextual framework for the design of the new system, including criteria, characteristics, components, an infrastructure architectural model and data structuring and organisation. An exploratory research methodology and qualitative research techniques were applied. Results attained from interviews conducted and literature consulted indicates a gap in the literature regarding the design of a data management system, specifically for geodetic data generated by HartRAO instrumentation. This necessitates the development of a conceptual framework for the design of a new GRDMS. Results are in alignment with the achievement of the research questions and objectives set for this study. / Information Science / M.A. (Information Science)