No abstract

No abstract

Preliminary investigations into the energy efficiency of manufacturing firms operating in South Africa have shown that no previous study of the barriers to energy efficiency has been conducted. This paper sets out to investigate whether there is an energy efficiency gap in medium to large manufacturing firms operating in the eThekwini municipal area. It goes on further to analyse the barriers to energy efficiency in such firms. These barriers are analysed by firm characteristics and across manufacturing sectors. The findings of this research indicate that more can be done to improve the energy efficiency profile within South African manufacturing subsectors. Policy-makers should take these findings into consideration when drafting new policy on energy efficiency. OPSOMMINGVoorlopige ondersoeke oor energiedoeltreffendheid in vervaardigingsaktiwiteite van maatskappye in Suid-Afrika toon dat daar geen vorige studies bestaan wat fokus op die struikelblokke van toepassing op bestaande energiedoeltreffendheid nie. Hierdie artikel ondersoek 'n energiedoeltreffendheidsgaping wat bestaan binne medium tot groot vervaardigingsmaatskappye binne die eThekwini munisipale gebied. Die ondersoek identifiseer en analiseer gepaardgaande beperkinge wat bestuurders binne sulke maatskappye verhinder om energie doeltreffendheid te implementeer. Die ondersoek en analise strek oor 'n aantal vervaardigingsektore. Die bevindinge van hierdie navorsing dui daarop dat heelwat meer bereik kan word in terme van energiedoeltreffendheid binne die verskeie vervaardigingsubsektore in Suid-Afrika. Hierdie gevolgtrekkings behoort in ag geneem te word deur beleidmakers tydens die opstel van 'n nuwe beleid oor energiedoeltreffendheid.

No abstract

Power losses are an important phenomenon in 2 nd type superconductors. Precise evaluation of power losses in superconducting coils is crucial for the design of novel machines such as superconducting motors or generators. Although AC losses are relatively easy to measure with electrical methods, it is more difficult to measure power losses in the DC mode, induced by varying external magnetic fields, such as occur in a real operating environment. Especially the problematic one could be the direct-drive wind generator, where several elements introduce nonsynchronous disturbances to the magnetic fields. Modelling had been carried out by numerous authors 1-4 in order to estimate the power losses in 2G HTS coils under various external DC or ripple fields; however experimental work in the area is less common due to the difficulty of conducting experiments and special equipment requirements. In this paper, power losses are experimentally measured by the calorimetric method.