Typescript

Typescript / 420 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, 1965

Thesis (M. Ag. Sci.)--University of Adelaide, 1978. / Includes bibliographical references.

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.

Trots att svensk ull är ett biobaserat, lokalt producerat och återvinningsbart material med stor cirkulär potential, kasseras mer än hälften av den svenska ullen som en biprodukt från köttindustrin. Den främsta orsaken är bristen på infrastruktur för inköp, produktion och storskalig insamling samt avsaknaden av standardiserade klassificerings- och kvalitetssäkringsmetoder. År 2023 publicerades den första svenska ullstandarden som en del av The Swedish Wool Initiative för att etablera ett nationellt klassificeringssystem som bygger på tio olika kvalitetstyper från A till I och syftar till att skapa ett gemensamt språk, möjliggöra storskalig insamling och kvalitetssäkring av svensk ull. Trots införandet av denna standard kvarstår flera utmaningar, såsom bristen på praktisk validering och standardens träffsäkerhet vilket leder till osäkerhet längs värdekedjan och produktionskomplikationer. Syftet med studien är att undersöka om ullen från tre svenska ullinsamlingar korrekt kan klassificeras enligt deras egen bedömning. Genom att noggrant granska och analysera ullen utvärderas hur väl den överensstämmer med den nya ullstandarden och hur ull från samma kvalitetstyp skiljer sig mellan leverantörerna. Analysen omfattar fiberkarakerisering baserad på parametrar som fiberlängd, finhet, krusighet, färg, vegetabiliskt material och tvärsnitt. Slutligen används statistiska metoder, inklusive ANOVA, för att identifiera spridning och signifikanta skillnader mellan de undersökta ullsorterna. Resultaten visade på att samtliga ullsorter faller under kvalitetstyp E enligt standardens intervall, men vissa resultat sträcker sig utanför intervallen. En ullsort (Ö1) avvek betydligt i krusighet och kunde potentiellt klassificeras annorlunda om krusighet var en parameter i standarden. Trots stora spridningar i parametrar som finhet, krusighet och fiberlängd, samt färg och vegetabiliskt material, visade ANOVA-analyser ingen signifikant skillnad mellan de olika ullinsamlingarna. Den observerade variationen inom insamlingarna var större än mellan dem, vilket tyder på stor variation i svensk ull utan tydliga skillnader mellan insamlingarna. / Despite being a bio-based, locally produced, and recyclable material with significant circular potential, more than half of Swedish wool is discarded as a byproduct of the meat industry. The main reasons for this are the lack of infrastructure for procurement, production, and large-scale collection, as well as the absence of standardized classification and quality assurance methods. In 2023, the first Swedish wool standard was published as part of The Swedish Wool Initiative to establish a national classification system based on ten different quality types from A to I. This initiative aims to create a common language, enable large-scale collection, and ensure the quality of Swedish wool. Despite the introduction of this standard, several challenges remain, such as the lack of practical validation and the accuracy of the standard, leading to uncertainty along the value chain and production complications. The purpose of this study is to investigate whether the wool from three Swedish wool collections can be correctly classified according to their own assessment. By carefully examining and analyzing the wool, the study evaluates how well it conforms to the new wool standard and how wool of the same class differs between suppliers. The analysis includes fiber characterization based on parameters such as fiber length, fineness, crimp, color, vegetable matter, and cross-section. Finally, statistical methods, including ANOVA, are used to identify the distribution and significant differences between the wool types studied. The results showed that all wool types fall under quality type E according to the standard's intervals, but some results extend beyond these intervals. One wool type (Ö1) deviated significantly in crimp and could potentially be classified differently if crimp was a parameter in the standard. Despite large variations in parameters such as fineness, crimp, fiber length, color, and vegetable matter, ANOVA analyses showed no significant difference between the different wool collections. The observed variation within collections was greater than between them, indicating a large variation in Swedish wool without clear differences between the collections.

Since the beginning of history the wool of sheep has been used by the human race. Its chief use has been and still is for clothing. Also, it is widely used for blankets, upholstery, carpets, and numerous other products. The wool industry is important to the state of Utah, which was the sixth largest producing state in the United States in 1958. Wool growers in Utah received approximately $7,897,000 in sales proceeds and government payments for wool sold during the 1958 marketing year (12).1

Wool as it is shorn from the sheep, is known as grease wool. The first tep in the manufacturing of wool is scouring, or removal of all grease and foreign matter. Within any given grade, as determined by length of staple and fineness of fiber, the yield of clean wool is the primary factor in determining the value of the original grease wool. The price of scoured or clean wool is multiplied by the percentage yield of clean wool to determine the value of the grease wool. Wool is graded and sorted before being scoured by the manufacturer. Large quantities are prepared for the scouring vate and the identity of the grower's clip is lost. Hence, the grower is entirely dependent upon the buyer's estimate of shrinkage or yield of clean wool, unless he obtains a representative sample of his clip and has it scoured to determine the yield. The object of the work reported in this thesis was to obtain information on the variability in yields of clean wool in Utah herds, and to add to work already done on methods of sampling and dtermining yields. Three methods have been used: (1) Whole fleece samples, (2) composite samples, and (3) side samples from individual sheep. Literature concerning each of these methods and other pertinent material is reviewed, and results obtained in Utah are presented.

Molecular and behavioural characterisation of ovine dermal papilla cells performed in this study indicate they synthesise a highly specialised extracellular matrix (ECM). This is conserved between different species and distinguishes papilla cells from dermal fibroblasts with which they have a common origin. The composition of the dermal papilla ECM is temporally and spatially regulated during wool follicle development. It was shown that the ECM associated with dermal papilla cells in foetal sheep skin becomes specialised in regard to chondroitin sulphate synthesis prior to the appearance of follicle primordia. Chrondroitin sulphate and fibronectin were present in the ECM of dermal papilla cells throughout follicle development and during fibre production. Cellular differentiation antigen 44 was present in the ECM od papilla cells exclusively during the formation of dermal papilla, while laminin was present in the dermal papilla ECM of fibre producing follicles only. Co-operation between chondroitin sulphate, fibronectin, and CD44 in regulating the agrregative and proliferative behaviour of papilla cells was demonstrated in culture. Finally, the inhibition of proteoglycan synthesis in newborn mouse skin was found to disrupt the growth of existing follicles and the generation of new ones. Together these findings demonstrate that chondroitin sulphate is intimately associated with the earliest interactions between epithelial and mesenchymal cells during the formation of follicle primordia. It is likely that the interactions specifically involve fibronectin and CD44, and possibly other ECM molecules which have he effect of regulating the behaviour of papilla cells / Doctor of Philosophy (PhD)

Bibliography: leaves [127-137]

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