No description available.

Bagasse is the fibrous derivative of sugar cane, that is grown on a commercial scale in many tropical and sub-tropical countries, where ideal climatic conditions are experienced. The seasonality of sugar cane presents storage problems for bagasse, since this lignocellulosic material is susceptible to degradation by a diverse range of microorganisms, mainly fungi. The decay that is brought about contributes largely to the losses of fibre in a bagasse pile. The surrounding microclimate, and conditions within the pile, needs to be carefully monitored in order to understand the factors that support the fungal populations and biochemical activity. The microclimate at the surface and inside the bagasse pile at a paper mill in Stanger (South Africa) was carefully monitored over a one-year storage period. Significant changes were noted in temperature, pH and moisture content, between the surface and the inside of the pile, as the pile aged. The data were compared to established parameters for bagasse preservation, and it was found that the temperature was lower than expected, thus promoting fungal growth. The pH was much higher (promoting bacteria and actinomycetes) and the moisture content was too low to produce anaerobic conditions. The environmental conditions in the bagasse pile at Stanger, therefore, promoted the proliferation of microbes, and consequently decay. Fungi that were present in the pile, were enumerated in order to investigate the diversity and fungal succession. There was a wider variety of species and higher numbers of fungi at the surface than inside the bagasse pile and the Shannon and Berger-Parker diversity confirmed these observations. Sorensons measure also showed that the types of fungal communities at the surface and inside the pile only started becoming similar toward the latter part of storage. When compared to models for abundance of species, conditions on the surface of the pile allowed maximum niche occupation at the beginning of storage, followed by the establishment of a mature community. The inside of the pile displayed minimal niche pre-emption followed by a state where most fungal species shared the domain. This study indicated that, as the storage time increased, the microbial communities became better established. Bagasse is rich in holocellulose, the basic raw material used for paper-making. Since there were many species of holocellulolytic fungi found growing on the surface and the inside of the bagasse pile, the activity of cellulases and xylanases were determined. These enzymes were found to be active at the surface and inside the pile. However, higher activities of both enzymes were noted inside the bagasse pile than on the surface. The higher levels of activity inside the pile, despite lower fungal numbers, suggested that fungal counts were not a clear indication of biomass or biochemical activity. It appeared that the environment on the inside of the bagasse pile promoted the establishment of specific fungal populations that bring about a high degree of degradation to fibre inside the bagasse pile. / Dissertation (MSc)--University of Pretoria, 2009. / Microbiology and Plant Pathology / unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21564号 / 理博第4471号 / 新制||理||1642(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 市川 温子, 教授 鶴 剛, 教授 中家 剛 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Nature reserves in the City of Tshwane are under threat from ecological and historically significant decay due to the less defined nature of these landscapes. Architecture in form, function and technology can be developed in the in-between of nature and urban to act as conservator for these nature reserves. Utilizing the natural resources of nature to produce products for the urban dweller within a space that conserves the historical protective layers of the site. The space of interaction between nature and urban becomes the conservator, acting as active protector in terms of sustainable production, education and urban dweller interaction with the nature reserve and its continuous history of protection. / Natuurreservate in die stad Tshwane word bedreig deur ekologiese en historiese betekenisverval weens die minder gedefinieerde aard van hierdie landskappe. Argitektuur in vorm, funksie en tegnologie kan ontwikkel word in die tussen ruimte van natuur en stedelike gebiede om as natuurbewaarder vir hierdie natuurreservate op te tree. Die natuurlike hulpbronne van die natuur kan gebruik word om produkte vir die stedelike inwoner te produseer binne ‘n ruimte wat die historiese beskermende lae van die terrein laat voortduur. Die ruimte van interaksie tussen natuur en stedelike word die bewaarder, wat optree as ‘n aktiewe beskermer in terme van volhoubare produksie, opvoeding en stedelike inwoner interaksie met die natuurreservaat en sy voortgesette geskiedenis van beskerming. / Mini Dissertation (MArch(Prof))--University of Pretoria, 2018. / Architecture / MArch(Prof) / Unrestricted

Acoustic models are useful tools to increase understanding of cochlear implant perception. Two particular issues in modelling cochlear implant perception were considered in the present study, which aimed at improving acoustic models. The first included an electricallayer in the model, while the second manipulated synthesis signal parameters. Two parts of the study explored the effects of current decay, compression function and simultaneous stimulation, by including the electrical layer. The SPREAD model, which incorporated this layer, yielded the asymptote in speech intelligibility at seven channels observed in CI listeners. It was shown that the intensity of border channels was deemphasized in relation to more central channels. This was caused by the one-sided effects of current spread from neighbouring channels for the border channels, as opposed to the two-sided effects for the more central channels. It was theorised that more compressive mapping functions would affect spectral cues and consequently speech intelligibility, but speech intelligibility experiments did not confirm this theory. A simultaneous analogue stimulation (SAS) model, which modelled simultaneous stimulation, yielded intelligibility results that were lower than those of the SPREAD model at 16 channels. The SAS model also appeared to introduce more temporal distortion than the SPREAD model. A third part of the study endeavoured to improve correspondence of acoustic model results with cochlear implant listener results by using nine different synthesis signals. The best synthesis signal was noise-band based. The widths of these increased linearly from 0.4 mm at the apical to 8 mm at the basal end. Good correspondence between speech recognition outcomes using this synthesis signal with those of CI listeners was found. AFRIKAANS : Akoesties modelle word algemeen gebruik om die persepsie van inplantingsgebruikers beter te verstaan. Twee benaderings tot die modellering van kogleêre inplantingsgebruikerpersepsies is voorgestel om akoestiese modelle te verbeter. In die eerste benadering is die generiese model verbeter deur die byvoeging van 'n elektriese laag en in die tweede benadering is sinteseseinparameters gemanipuleer om die ooreenkoms met inplantingsgebruikersuitkomste te verbeter. Twee dele van die studie het die effek van stroomverspreiding, samedrukkings-funksie en gelyktydige stimulasie ondersoek deur die insluiting van die elektriese laag. Die SPREAD-model het die asimptoot in spraakherkenning by sewe kanale getoon. Die intensiteit van grenskanale is onderbeklemtoon in verhouding met meer sentrale kanale. Dit is veroorsaak deur die eensydige effekte van stroomverspreiding vir die grenskanale, teenoor die tweesydige effekte wat meer sentrale kanale tipies beïnvloed. Die model het gesuggereer dat meer samedrukkende funksies spektrale inligting sou affekteer, maar spraakherkenningsdata het nie hierdie teorie bevestig nie. Die gelyktydige- analoogstimulasiemodel, wat gelyktydige stimulasie gemodelleer het, het soortgelyke tendense getoon, maar met meer temporale effekte as die SPREAD-model. Die gelyktydige- analoogstimulasiemodel-model se resultate was ook swakker by 16 kanale as die SPREAD-modelresultate. Die derde deel van die studie het gepoog om beter ooreenkoms tussen modeluitkomste en inplantingsgebruikeruitkomste te verkry deur nege verskillende sinteseseine te gebruik. Die beste sintesesein was die ruisband met veranderende wydte; hierdie wydte het verbreed vanaf 0.4 mm by die apeks tot by 8 mm by die basis. 'n Goeie ooreenkoms is verkry tussen modeluitkomste en inplantingsgebruikeruitkomste deur hierdie sintesesein te gebruik. / Thesis (PhD)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / Unrestricted

We have performed a careful measurement of the shape of the beta spectrum of He⁶. A detailed study of the phenomenon of electron scattering in our thin lens magnetic spectrometer enabled us to interpret the spectrum shape from the end point at Wₒ = 3.50 ± .02 Mev. down to 1/14 Wₒ = 0.250 Mev. The experimental shape has been compared with the theoretically predicted shape for allowed spectra. The influence of the pseudoscalar interaction on the shape of the He⁶ spectrum has also been considered. From these measurements we have been able to set limits on the Fierz interference in the Gamow-Teller interaction as well as on the magnitude of the pseudoscalar coupling constants. These limits have been interpreted in terms of the relative magnitudes of the axial vector, pseudoscalar, and tensor coupling constants using the two component theory of the neutrino and assuming that the complete beta decay Hamiltonian proposed by Lee and Yang is or is not invariant under time reversal. We have also calculated the effect on the spectrum shape of the production of inner Bremsstrahlung in beta decay and have shown this effect to be at the limit of experimental detectability.

要旨ファイルを2017-04-17に差替え / 京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19502号 / 理博第4162号 / 新制||理||1598(附属図書館) / 32538 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 中家 剛, 教授 谷森 達, 准教授 成木 恵 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19882号 / 理博第4209号 / 新制||理||1605(附属図書館) / 32959 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 中家 剛, 教授 谷森 達, 教授 永江 知文 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

No description available.

No description available.