No description available.

This diploma thesis deals with the sensory evaluation of selected types of non-chocolate sweets. In the theoretical part the production technology of non-chocolate sweets is described, including raw materials needed. Furthermore, basics of sensory analysis with characteristics of sensory evaluation and selected sensory methods are mentioned. The experimental part deals with the sensory evaluation itself; the selected sensory methods were applied on samples of gummy sweets. Four colours/flavours (strawberry, orange, lemon, apple) from five producers were chosen for evaluation, together 20 samples. The aim was to assess the differences in sensory quality of samples of the same type from different producers. Untrained assessors, from Faculty of Chemistry BUT, were invited for sensory evaluations. Significant differences were found among the samples, glossy appearance and pleasant characteristic taste contributed to the positive evaluation, on the contrary the rigid texture, bland taste and odour and possible off-flavour contributed to the negative evaluation.

<p dir="ltr">The Mu2e experiment is searching for Beyond-Standard-Model, Charged Lepton Flavor Violation (CLFV) in the muon capture reaction μ⁻+ Al → e⁻ + Al. To compare the accessible energy scale of this experiment, the Large Hadron Collider (LHC) is capable of observing new physics at the few TeV mass scale. However, by searching for μ-to-e conversion at a branching ratio sensitivity of 10⁻¹⁷, Mu2e will probe for new physics at mass scales up to 10³ ∼ 10⁴TeV, far beyond the reach of any planned accelerator and surpassing the current world’s best limit by 10⁴ times. In addition, there is no competing Standard Model process that produces this decay to a branching ratio level < 10⁻⁵⁴. To report a reliable result, the number of stopped muons will be normalized to 10% precision utilizing two γ-ray transitions and one x-ray atomic transition. The first, directly proportional to the CLFV signal, is the 1808.7 keV γ-ray emitted promptly in the muon capture process. The second, the 2p→1s atomic transition of muonic aluminum, is the 346.8 keV x-ray line. The third, is the 844 keV γ-ray from the β-decay process. These signals need to be measured in the presence of an energy flux background of 3.2 x 10⁸TeV/sec, consisting of muons, electrons, neutrons, x-rays and γ-rays. Here, two com- 11 photon counting detectors are used in the luminosity measurement. One of them, the LaBr₃ detector, is capable of high rate operation up to and above 800 kcps and energy resolution of 0.7%, producing highly accurate statistical measurements. The other, the HPGe detector is capable of energy resolution of 0.1%, with limited rate capability ∼ 70 kcps, yet producing measurements having low systematic error. Once signals are found within the background, corrections must be understood and applied including: geometric factors, detector efficiency, branching ratio of the observed physics pro- cesses, signal loss due to propagation to the detector, interfering lines, event loss due to pile-up, event loss due to algorithm miscalculation, time evolution of the signal, and others. The normalization measurement will be reported out in real time every 5 to 10 minutes, and a comprehensive off-line analysis will be undertaken using merged data sets.</p>

Semileptonic B decays of the type Bq⁰→Dq⁻μ⁺ν (where Dq⁻→K⁻K⁺pie⁻) are selected and their lifetimes are corrected using a statistical simulation-based correction called the k-factor. Using 1 fb⁻¹ of LHCb data the B⁰ and Bs⁰ mixing frequencies are measured to be Deltamd = ( 0.503 ± 0.011 (stat) ± 0.013 (syst) ) ps⁻¹ and Deltams = ( 17.93 ± 0.22 (stat) ± 0.15 (syst) ) ps⁻¹. We exclude the null hypothesis of no mixing for the B⁰ and Bs⁰ by 5.8 and 13.0 standard deviations respectively. This is the first observation of Bs Bsbar mixing using only semileptonic B decays. The lepton flavour violating decay D⁰→eμ is searched for, using tagged D⁰ decays from D*→D⁰pie, and the measurement is normalised using D⁰→K⁻pie⁺ decays. No evidence is seen of an excess over the expected background and so a limit is placed B(D⁰→eμ) < 1.3×10⁻⁸ at a 90% confidence level using 3 fb⁻¹ of LHCb data. This improves the previous measurement by a factor of 20 and is the world's best measurement. Possible upgrades to the LHCb VELO detector are simulated and aspects of the upgraded detector are optimised to ensure that all tracks within the angular acceptance can be detected with high precision. Finally the simulated performance of the current and upgraded VELO detectors are compared.

We present a calculation of vector and axial-vector form factors for each of the octet hyperon semi-leptonic transition matrix elements by using the techniques of lattice QCD where simulations were performed with Nf = 2 + 1 flavours of dynamical O(a)-improved Wilson fermions. We also study the electromagnetic form factors, axial charges and other properties of octet baryons. Errors due to extrapolation to zero transferred momentum are reduced by applying a twist to the boundary conditions on the lattice. Our form factor results compare favourably with experiment and other lattice QCD determinations. By considering an expansion about the SU(3)-flavour symmetric limit we seek to investigate and quantify the symmetry breaking effects in these matrix elements due to the mass splitting between the strange and light quarks. We find good agreement with the Ademollo-Gatto theorem for the vector form factor, a measurable amount of breaking in the axial-vector form factor and significant effects in the weak magnetism form factor. Knowledge of the parameterisation of SU(3)-flavour symmetry breaking allows for a series of constrained fits to be made to the form factor results which are used to arrive at a 'baryonic' estimation of the Cabibbo-Kobayashi-Maskawa matrix element |Vus|.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Key research areas in modern enology are related to the production of wine of consistent quality, as well as to the improvement of existing wine quality through the enhancement of the sensory properties of wine. The formation of glycerol during alcoholic fermentation is highly relevant to both these issues. Since the early years of the zo" century, glycerol has been positively associated with the quality of wine and it is thought to impart important mouth-feel sensations such as "viscosity", "smoothness" and "body". In general, it is considered that glycerol concentrations higher than those normally found in wine, can contribute towards the improvement of wine quality. It has also been suggested that increased concentrations of glycerol can enhance the aroma of wine. On the basis of these perceptions, several strategies have been developed to favour the production of glycerol during the fermentation process and over a period of years, a large volume of data has been collected that relates to various aspects regarding glycerol production during alcoholic fermentation. To date, however, several aspects regarding the relationship between glycerol and wine quality remain unclear. The reasons for this situation can mainly be ascribed to the lack of reliable analytical data to serve as a basis for investigating the relationship between glycerol and wine quality, as well as the preponderance of empirical and anecdotal evidence. Despite numerous opinions regarding optimal glycerol concentrations in wine, glycerol is indeed seldom assayed on a routine basis and targets with respect to specific wine grape cultivars and glycerol concentrations have largely remained unspecified. To date, very little information regarding glycerol concentrations in South African wines has been published. The analytical techniques that are most frequently used for the quantification of glycerol in grape juice, fermenting must and wine are not easily automated and this aspect placed severe limitations on the generation of large volumes of analytical data on glycerol concentrations in these matrices. This project was undertaken with the aim to holistically address some of the unresolved issues relating to the relationship between glycerol and wine quality. This also implied the development and optimisation of analytical techniques suitable for the rapid and accurate determination of glycerol in fermentation media, as well as in finished wine. In the first stage of this project a quantitative database was established that contained the analytical data on the glycerol concentrations of a statistically significant number of wines of adjudged quality, as well as additional information for each wine regarding the geographic origin, vintage, routine chemical analyses and the yeast strain(s) used for the production of the wine. The relevance of glycerol in wine for the modern South African winemaker was evaluated through the establishment of a quantitative database that contained the opinions of an expert panel of 15 South African winemakers, enologists and wine chemists on topics relating to glycerol in wine. In the second stage of the project the data captured in the databases were used to investigate aspects regarding the relationship between glycerol and wine quality. From the data captured in the qualitative database, it was clear that the topic regarding glycerol in wine was important to the South African winemakers and it was also evident that there was a need for the development and optimisation of methods suitable for the routine analysis of the glycerol concentrations in grape juice, fermenting must and wine. The opinions of the panel members also highlighted the issue that the mouth-feel property of wine was considered to be an area where the quality of some wines could be further improved. The quantitative database contained the information on the glycerol concentrations of 450 commercial South African table wines of adjudged quality. The premium cultivars Chardonnay, Chenin blanc, Sauvignon blanc, Cabernet Sauvignon, Merlot, Shiraz and Pinotage were used for the purpose of investigating the relationship between glycerol concentration and wine quality. The wines represented a wide variety of wine styles, including dry white, off-dry white, dry red and late harvest wines. The average glycerol concentration was significantly associated with the wine style. In white wines the average glycerol concentration was much lower than in the red wines (6.82 gIL versus 10.49 gIL, respectively). No significant relationship between the final glycerol concentration and the geographic origin, vintage and the yeast strain used for the fermentation was found. Wine quality could not be significantly associated with glycerol concentration in the red wines. In the white wines, the relationship between glycerol concentration and wine quality was significant, but due to the very small differences in the average glycerol concentrations of the wines of different quality ratings, the statistical significance is probably of little practical value. The effect of glycerol on the volatility of a selection of esters and higher alcohols was also investigated. Solid-phase microextraction, followed by gas chromatography, was used to analyse the composition of the headspace at equilibrium between the liquid phase and the gas phase of a model wine, and a dry white wine that contained a basal concentration of 5.4 gIL glycerol. Results showed that incremental increases in the glycerol concentrations over a range of 1 -10 gIL in the model wine and in a Chenin blanc wine, were not accompanied by a proportional increase or decrease in the abundance of the aroma components in the headspace. The volatile components tested were isoamyl acetate, ethyl butyrate, ethyl valerate, ethyl lactate, ethyl hexanoate, hexyl acetate, isoamyl alcohol and isobutanol. For all the volatile components tested, the difference between the headspace composition of samples containing the lowest glycerol concentration, and those containing the highest glycerol concentration, was not significant. However, sufficient experimental evidence was obtained to indicate that increasing glycerol concentrations had an effect on the volatility of aroma components, and that the effect is of a complex and non-linear nature. In the third phase of the work Fourier transform infrared spectroscopy (FT-IR) was used to establish and optimise methods for the accurate and rapid quantification of glycerol in wine. For this purpose calibrations were developed for the quantification of glycerol in dry wine and late harvest wines. The accuracy of prediction was evaluated by means of the standard error of prediction that was 0.38 gIL for the dry wines and 0.65 gIL for the sweet wines. Large variations are introduced in the FT-IR spectra of wine by factors such as process technology, cultivar and geographic origin, and this variation can have an effect on the accuracy of the analytical data generated when employing FT-IR spectroscopy. Using glycerol prediction in wine as a model system, principal component analysis of the FT-IR spectra was done in order to establish quality control measures for the detection of poorly predicted, or outlier samples. A classification model, based on principal component analysis, was established that enabled the interpretation and classification of the outlier samples in the data set in 100% of the cases tested. This work forms the basis for expanding the quality control measures for the detection of wines of which the FT-IR spectra are highly unnatural, as well as for establishing quality control measures to ensure that accurate analytical data are generated when FT-IR is used. FT-IR spectroscopy was also used to develop a rapid screen for the evaluation of the fermentation profiles of wine yeasts. For this purpose, a selection of wine yeasts, which included commercial wine yeasts frequently used in winemaking in South Africa, as well as a selection of hybrid Saccharomyces cerevisiae yeasts, that were obtained through a selective breeding strategy aimed at increasing glycerol concentrations were used. Calibrations necessary for the accurate quantification of glycerol, volatile acidity, ethanol, reducing sugar and glucose, in Chenin blanc must and a synthetic must were developed and optimised. This work forms the basis upon which the scope of the analysis, both in terms of the number of components that can be measured, as well as the medium in which the yeasts are being evaluated, can be enlarged. This would be valuable for future applications in both the research as well as the industrial environment. The method that was developed serves to illustrate how this application can play a supportive role in yeast development programmes, through the speeding up of the initial stages of yeast strain evaluation. / AFRIKAANSE OPSOMMING: Navorsing in moderne wynkunde is sterk gefokus op die produksie van wyn waarvan die kwaliteit van In volhoubare goeie peil is, sowel as die verdere verbetering van bestaande wynkwaliteit, deur In verhoging van die sensoriese eienskappe van wyn. Die vorming van gliserol tydens alkoholiese fermentasie het betrekking op beide hierdie aspekte. In Opvatting wat wyd gehuldig word en wat reeds sedert die vroeë jare van die 20e eeu geld, impliseer dat gliserol In positiewe bydrae lewer tot wynkwaliteit. Oor die algemeen word dit beskou dat gliserolvlakke hoër as wat normaalweg in wyn aangetref word, kan bydra om die kwaliteit van die wyn nog verder te vehoog. Daar is ook spekulasie dat verhoogde gliserolvlakke in wyn die intensiteit van die aroma van wyn kan verhoog. Hierdie opvattings het tot gevolg gehad dat veskeie strategieë ontwikkel is om die gliserol vlakke wat tydens die fermentasieproses gevorm word, te verhoog. Baie min inligting oor die gliserolinhoud van Suid-Afrikaanse wyn is tot onlangs gepubliseer. Ten spyte van die opvattings oor gliserol en wynkwaliteit wat reeds oor In lang tydperk gehuldig word, bly sekere aspekte van die verwantskap tussen gliserol en wynkwaliteit nog steeds onduidelik. Redes vir hierdie situasie kan hoofsaaklik toegeskryf word aan die totale afwesigheid van betroubare en substansiële eksperimentele data wat as basis kan dien vir die evaluering van die algemene opvattings aangaande die verwantskap tussen gliserol en wynkwaliteit. Die inligting wat wel beskikbaar is, is verder ook oorwegend van In empiriese aard. Huidig word gliserol selde op In roetine basis in die analitiese laboratorium bepaal, hoofsaaklik omdat die bestaande metodes tydrowend is en nie maklik geoutomatiseer kan word nie. In hierdie studie is In kwantitatiewe databasis opgestel waarin die inligting ten opsigte van die gliserolvlakke van 450 kommersiële Suid-Afrikaanse tafelwyne waarvan die kwaliteit beoordeel is, vervat is. Die kultivars Chardonnay, Chenin blanc, Sauvignon blanc, Cabernet Sauvignon, Merlot, Shiraz en Pinotage is gebruik vir hierdie doel en die seleksie van wyne was verteenwoordigend van In wye verskeidenheid wynstyle, insluitende droë wit-, halfdroë wit-, droë rooi- en laatoeswyne. Die gemiddelde gliserolvlakke in die witwyne was heelwat laer as die gemidelde gliserolvlakke in die droë rooiwyne (6.82 gIL teenoor 10.49 gIL, onderskeidelik). Geen beduidende verwantskap kon aangetoon word tussen die gliserolkonsentrasie in die wyn en die geografiese oorsprong, oesjaar, en die gisras wat gebruik is in die produksie van die wyn nie. Die kwaliteit van rooiwyn kon nie beduidend met die gliserolkonsentrasie geassosieer word nie. In die geval van wit wyn was die verwantskap statisties beduidend, maar die verskille was klein en moontlik nie van veel praktiese waarde nie. Die aktualiteit van gliserol vir die moderne Suid-Afrikaanse wynmaker is geëvalueer op grond van die opinies van In paneel van 15 Suid-Afrikaanse kundiges, rakende aspekte wat verband hou met die algemene opvattings oor gliserol en wyn. Die paneel het bestaan uit wynmakers, wynkundiges en chemici. Die opinie van die panel is deur middel van "n vraelys bekom en is vervat in "n kwalitatiewe databasis. Die resultate van hierdie menigspeiling het getoon dat gliserol wel vir die Suid- Afrikaanse wynmakers belangrik is en dit het ook die behoefte uitgewys vir die ontwikkeling en optimisering van metodes wat geskik is vir die roetine analyses van gliserol in wyn. Die invloed van gliserol op die vlugtigheid van "n seleksie van hoëralkohole en esters is ondersoek in "n model wyn sowel as "n wit wyn, waarvan die basiese gliserolkonsentrasie 5.4 gIL was. Soliede-fase mikroekstraksie van die gasfase van wyn is opgevolg met "n gaschromatografiese analise. Resultate het getoon dat "n stapsgewyse toename in die gliserol konsentrasie, oor "n konsentrasie reeks van 0 - 10 gIL in die model wyn, en 0 - 15 gIL in die wit wyn, nie gepaard gegaan het met "n reglynige toename of afname in die konsentrasie van die aromakomponente nie. Vir al die komponente wat ondersoek is, was die samestelling van die gasfase in monsters wat die laagste gliserol konsentrasie gehad het, teenoor dié wat die hoogste gliserol konsentrasie gehad het, nie beduidend nie. Nietemin het die resultate getoon dat gliserol wel "n effek het op die vlugtigheid van die aroma komponente wat in hierdie ondersoek gebruik is, maar dat die aard van die effek kompleks en nie-liniê is. Fourier-transformasie-infrarooispektroskopie (FT-IR) is gebruik om die metodes vir die analise van gliserol in wyn sodanig te optimiser, dat vinnige en akkurate bepalings op "n roetine basis in wyn gedoen kan word. Kalibrasies is ontwikkel vir die kwantifisering van gliserol in droëwyn en laatoeswyn. Die standaard voorspellingsfout van die kalibrasies wat ontwikkel is, was 0.38 gIL in droëwyn en 0.65 gIL in die geval van laatoeswyn. Inherente variasie in die FT-IR-spektra word deur eksterne faktore soos die proses tegnologie wat gebruik is om die wyn te berei, die kultivar en geografiese oorsprong van die wyn veroorsaak en hierdie variasie kan "n effek hê op die voorspelingsakkuraatheid van FT-IR spektroskopie. Om die effek van hierdie variasie op die akkuraarheid van die analitiese data te evalueer, is die voorspelling van gliserol as modelsisteem gebruik. Hoofkomponentanalise van die FT-IR spektra is gedoen om dié wyne met onnatuurlike FT-IR-spektra te identifiseer, ten einde beheer oor die akkuraatheid van die analitiese data uit te oefen. "n Verdere model wat ook gebaseer is op hoofkomponentanalise van die FT-IR-wynspektra is ontwikkel vir die interpretasie en klassifikasie van wynmonsters met onnatuurlike FT-IRspektra. Met die model wat ontwikkel is kon onnatuurlike wynmonsters met "n akkuraatheid van 100% gëidentifiseer word. Hierdie werk vorm die basis waarop kwaliteitsbeheer verder uitgebrei kan word sodat wyne met onnatuurlike spektra gëidentifiseer kan word, sowel as om te verseker dat akkurate data gegenereer word as FT-IR as analitiese metode gebruik word vir die kwantifisering van gliserol in wyn. FT-IR spektroskopie is ook gebruik om "n vinnige skandeerproses te ontwikkel waarmee die fermentasieprofiele van wyngiste geëvalueer kan word. Die seleksie giste wat vir hierdie doel gebruik is, sluit kommersiële Suid-Afrikaanse wyngiste in, sowel as hibriede Saccharomyces cerevisia-giste wat normaalweg hoër vlakke van gliserol tydens die fermentasieproses produseer. Kalibrasies is ontwikkel vir die akkurate kwantifisering van gliserol, vlugtige suur, alkohol, reduserende suiker en glukose, in Chenin blanc-mos sowel as in 'n sintetiese medium. Hierdie werk vorm die basis waarop verdere uitbreidings gedoen kan word, sodat meer metaboliete gemeet kan word en 'n groter verskeidenheid van fermentasiemedia gebruik kan word. Hierdie ontwikkeling is waardevol vir toekomstige toepassings in die navorsings- sowel as die industriële omgewing. Die metode wat ontwikkel is illustreer ook hoe hierdie toepassing 'n ondersteunende rol kan speel in wyngisontwikkelingsprogramme deur die aanvanklike evalueringsproses van die giste te versnel.

Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Scotch whiskey is of two main types, namely Scotch malt whiskey, made from malted barley alone, or Scotch grain whiskey, made from cereals, such as wheat or maize, together with malted barley. In both processes, the enzymes from the barley are responsible for starch conversion and should always be derived entirely from the malted barley. No exogenous enzymes are allowed to be added to any mashing. The enzymes involved in the conversion process to fermentable sugars, are the aand p-amylases, limit dextrinase and p-glucosidase. Maize, on the other hand, contains no enzyme activity, therefore enzymes need to be added when producing whiskey from maize alone. In other whiskey-producing countries where maize is freely available and cheaper than barley, the use of exogenous enzymes are allowed in the mashing process and is crucial for the formation of fermentable sugars from complex carbohydrates. The cost of the enzymes, however, can push the production cost of whiskey to higher levels. Saccharomyces cerevisiae does not have any amylolytic activity, but is an excellent fermenter and produces favourable organoleptic notes, which makes it very suitable for producing potable spirit. Efforts have been made to genetically improve industrial strains, relying on classical genetic techniques followed by the selection of broad traits, such as ethanol tolerance, absence of off-flavours and carbohydrate/starch utilisation. No strain has thus far been selected for total starch degradation during the fermentation of whiskey mash. Over the last decade, considerable progress has been made in the development of genetically improved strains for the distilling, wine, brewing and baking industries. The expression of heterologous genes introduced a new dimension in approaches to the genetic improvement of industrial strains. It would therefore be cost-effective to use a yeast strain that can produce active and sufficient enzymes to ferment raw starch efficiently to alcohol without lowering the quality of the end product. No such strain has been developed to date, but the continuous improvement of starch-utilising strains has made this goal more achievable. Two a-amylase genes, namely LKA 1 and LKA2, were previously isolated from Lipomyces kanonenkoae. In this study, we selected 4 strains on the basis of criteria that are important for whiskey-specific strains. The selected strains were transformed with LKA 1, as well as with a combination of LKA 1 and LKA2 genes. The wine yeast VIN13 was included in the transformation of LKA1 and LKA2 because of its rapid fermentation rate. The genes were integrated into the genomes of the yeast strains and were stable after many generations. Assays showed that a significant increase in enzyme activity was induced in the whiskey strains, compared to the untransformed strains. The strains also showed good fermentation ability in whiskey fermentations, although optimum alcohol production was still not achieved. / AFRIKAANSE OPSOMMING: Skotse whiskey bestaan uit 2 tipes, nl. mout whiskey, gemaak slegs van mout d.w.s. gars wat die mout proses ondergaan het, en graan whiskey wat gemaak word van gewasse soos mielies of koring, waarby mout gevoeg word. Die ensieme afkomstig van die mout is verantwoordelik vir die omsetting van stysel na fermenteerbare suikers en geen eksogene ensieme mag by die gars- of graanmengsel gevoeg word nie. Die ensieme wat betrokke is by die omsetting van stysel, is die a- en ~- arnitases, limiet dekstrinase en ~-glukosidase. Mielies bevat geen ensiemaktiwiteit nie, dus moet ensieme by die proses gevoeg word indien slegs mielies vir die vervaardiging van whiskey gebruik word. In whiskey produserende lande waar mielies vryelik beskikbaar is en goedkoper is as gars, word eksogene ensieme by die graanmengsel gevoeg vir die vrystelling van fermenteerbare suikers vanaf komplekse koolhidrate. Die hoë koste van die ensieme kan egter die produksiekoste van whiskey verhoog. Saccharomyces cerevisiae besit geen amilolitiese aktiwiteit nie, maar is 'n uitstekende fermenteerder en produseer gewensde organoleptiese geure. Om hierdie redes is S. cerevisiae baie geskik vir die produksie van drinkbare etanol. Navorsingspogings om industriële rasse geneties m.b.v. klassieke genetiese metodes te verbeter, kom wydverspreid in die literatuur voor. Dit sluit in die seleksie van rasse met 'n verskeidenheid van eienskappe soos etanol toleransie, die afwesigheid van afgeur produksie en koolhidraat/stysel benutting. Geen ras is egter tot op hede geselekteer vir totale stysel afbraak gedurende fermentasie nie. Groot vordering is gedurende die laaste dekade gemaak in die ontwikkeling van genetiese verbeterde rasse vir die wyn- stokery- en brouers industrieë. Die uitdruk van heterogene gene in gisrasse gee 'n nuwe dimensie aan die genetiese verbetering van industriële rasse. Die gebruik van 'n gisras wat aktiewe en genoegsame ensieme produseer om rou stysel te fermenteer, sonder om die kwalitiet van die eindproduk nadelig te beïnvloed, kan die produksiekoste van whiskey aansienlik verminder. Geen gisras met hierdie eienskap is tot op hede ontwikkel nie, maar die voortdurende verbetering van rasse om stysel af te breek maak hierdie doel meer bereikbaar. Twee a-amilase gene, nl. LKA 1 en LKA2 is voorheen uit Lipomyces kononenkoae geïsoleer. In hierdie studie is 4 gisrasse geselekteer op grond van die kriteria wat nodig is vir whiskey giste. Die geselekteerde rasse is getransformeer met LKA 1 sowel as 'n kombinasie van LKA 1 en LKA2 gene. Die wyngis VIN13 is ingesluit by die transformasie met die LKA1 en LKA2 gene, omrede VIN13 bekend is as 'n vinnige fermenteerder. Die gene is geïntegreer in die genoom van die verskillende gisrasse en is stabiel na vele generasies. Die getransformeerde rasse het 'n betekenisvolle verhoging in ensiemaktiwiteit teenoor die nie-getransformeerde rasse getoon. AI die transformante het ook goeie fermentasie vermoë getoon in whiskey fermentasie proewe. Optimum alkoholproduksie is egter nie verkry nie.

The role of energy as a stimulant for economic growth and environmental sustainabilityof any nation has made the focus on green fuels, including fermentative hydrogen (bioH2) andmethane (bioCH4), to be a priority for the World’s policy makers. Nigeria, as the most populousAfrican country, with worsening energy crisis, can benefit from the introduction of the bioH2 andbioCH4 technologies into the country’s energy mix, since such technologies have the potential ofgenerating energy from organic wastes such as fruit waste.Fruit waste was studied in detail in this work because of its great economic andenvironmental potential, as large quantities of the wastes (10–65% of raw fruit) are generatedfrom fruit consumption and processing. Meanwhile, bioH2 and bioCH4 productions involvinganaerobic microorganisms in direct contact with organic wastes have been observed to result insubstrate and product inhibitions, which reduce the gas yields and limit the application of thetechnologies on an industrial scale. For example, in this study, the first experimental work todetermine the effects of hydraulic retention times and fruit mixing on bioH2 production fromsingle and mixed fruits revealed the highest cumulative bioH2 yield to be equivalent to 30% ofthe theoretical yield. However, combining the fermentation process with the application ofmembrane encapsulated cells and membrane separation techniques, respectively, could reducesubstrate and product inhibitions of the microorganisms. This study, therefore, focused on theapplication of membrane techniques to enhance the yields of bioH2 and bioCH4 productions fromthe organic wastes.The second experimental work which focused on reduction of substrate inhibition,involved the investigation of the effects of the PVDF membrane encapsulation techniques on thebioH2 and bioCH4 productions from nutrient media with limonene, myrcene, octanol and hexanalas fruit flavours. The results showed that membrane encapsulated cells produced bioCH4 fasterand lasted longer, compared to free cells in limonene. Also, about 60% membrane protectiveeffect against myrcene, octanol and hexanal inhibitions was obtained. Regarding bioH2production, membrane encapsulated cells, compared to free cells, produced higher average dailyyields of 94, 30 and 77% with hexanal, myrcene and octanol as flavours, respectively. The finalpart of the study, which was aimed at reducing product inhibition, involved the study of theeffects of membrane permeation of volatile fatty acids (VFAs) on the bioreactor hydrodynamicsin relation to bioH2 production. The investigation revealed that low transmembrane pressure of104Pa was required to achieve a 3L h-1m-2 critical flux with reversible fouling mainly due to cakelayer formation, and bioH2 production was also observed to restart after VFAs removal.The results from this study suggest that membrane-based techniques could improve bioH2and bioCH4 productions from fermentation media with substrate and product inhibitions.

A precision measurement of the CKM angle γ from tree-level processes is one of the principal goals of the LHCb experiment. The results from this study are compared to predictions from two different theoretical models and from the default LHCb tuning of the PYTHIA Monte Carlo event generator, and the results shown to be in good agreement. The cross-section results are also compared to an independent LHCb measurement. LHCb analyses rely on the ability to identify kaons and pions with a high efficiency and low mis-identification rate, achieved by two Ring Imaging Cherenkov (RICH) detectors. To ensure optimal performance of the RICH detectors, the time alignment of the Level-0 (L0) front-end electronics modules has been optimised using a combination of a pulsed laser system installed in the LHCb cavern and pp collision data. After the time-alignment procedure, the L0 modules have been time-aligned to within approximately ° 1ns across both detectors.

An accurate determination of the angle γ of the Unitary Triangle is one of the most important goals of the LHCb experiment. The LHCb detector is a single-arm spectrometer at the LHC, optimised for beauty and charm flavour physics. As the angle γ is the least experimentally constrained parameter of the Unitary Triangle, its precise experimental determination can be used to test the validity of the Standard Model. The Unitary Triangle phase γ can be extracted in B → DK decays at tree-level, exploiting the interference between b → c(ūs) and b → u(c̄s) transitions. This interference is sensitive to γ and can give measurable charge asymmetries. In particular, γ ≠ 0 is required to produce direct CP violation in B decays and this is the only CP-violating mechanism for the decay of charged B^± mesons. In this thesis, an analysis of CP violation in B^± → DK^± and B^± → Dπ^± decays is presented, where the D meson is reconstructed in the two-body final states: K^±π^∓, K⁺K⁻, π⁺π⁻ and π^±K^∓. The analysis uses the full 2011 LHCb dataset of 1.0 fb^-1, collected from pp collisions at √s = 7 TeV. Several CP-related quantities, e.g the ratio of B → DK and B → Dπ branching fractions and their charge asymmetries, are measured via a simultaneous fit to the invariant mass distributions of the modes considered. The suppressed B^± → DK^± mode is observed for the first time with ≈ 10σ significance. Once all measurements are combined, direct CP violation is established in B^± decays with a total significance of 5.8σ.