Includes bibliographical references (leaves 154-179).

Includes bibliographical references (leaves 154-179). / x, 179 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Tests whether follicle shutdown affects staple strength using Merino sheep exposed to cortisol to vary wool growth rate. A correlation exists between follicle shutdown levels and staple strength. Tests also whether breed affects follicle shutdown. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1998

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: In the wool trade the mean diameter of wool is a primary indicator of wool quality. It is currently standard practice for a wool grower to send samples to a laboratory for classification before and after shearing. The devices used to make measurements on samples are often big and bulky and sensitive to the environment, thus they are not ideally suited for on site testing. A brief discussion of the industry is given with background information on existing devices as well as information about organic fibres in general. We test an experimental device which has the potential to be robust and compact based on the Fourier optical principle. Two initial designs are considered and the transmission design is further developed into a working system. The working system is evaluated in a sample measurement experiment. In our sample measurement experimentwe determine the mean diameter of a set of samples which has been analysed by an external testing body such that the measurements could be compared. / AFRIKAANSE OPSOMMING: In diewol bedryfword die gemiddelde diameter vanwol as ’n primêre kwaliteitindeks gebruik. Dit is tans gebruiklik om wol monsters na ’n laboratorium te stuur vir klassifikasie voor en na die skape geskeer word. Die toestel wat gebruik word om die wol monsters te klassifiseer is geneig om groot, lomp en sensitief vir die omgewing te wees en is sodoende nie ideaal vir veld gebruik nie. ’n Kort uitleg van die industrie word gegee tesame met agtergrond inligting van bestaande toestelle asook agtergrond oor organiese vesels in die algemeen. Ons toets ’n eksperimentele toestel wat potensieel kompak en aanpasbaar kan wees en gebaseer is op die Fourier optiese prinsiep. Twee aanvanklike ontwerpe word oorweeg en eindelik word die transmissie ontwerp verder ontwikkel tot ’n werkende sisteem. Die sisteem word geëvalueer in ’n monster meting eksperiment. In die monster meting eksperiment bepaal ons die gemiddelde diameter van ’n stel monsters waarvan die gemiddelde diameter deur ’n eksterne liggaam bepaal is om sodoende die metings te kan vergelyk.