Submitted in part fulfilment of the requirements for the Master's Diploma of Technology: Chemistry, M. L. Sultan Technikon, 1992. / 2- Vinylfuran has been synthesised from furan, obtained from furfural a degradation product of bagasse, and has the potential to be used as a monomer in the Polymer Industry. Furan was successfully reacted with ethylene under catalytic conditions of palladium (II) acetate and copper (II) acetate to produce 2-vinylfuran, via a direct substitution reaction, at atmospheric pressure and a temperature of 9Y C for two hours in dimethylformamide. / M

La qualité de l’air que nous respirons à l’intérieur des espaces clos est devenue une préoccupation environnementale majeure. Il est aujourd’hui avéré que la présence de microorganismes dans l’air intérieur peut avoir des conséquences néfastes sur la santé humaine. Les systèmes de ventilation, lorsqu’ils sont mal entretenus, peuvent être eux-mêmes la source de bioaérosols suite à la contamination de leurs filtres. Afin de pallier ce problème, des filtres photocatalytiques ont été développés et testés dans des centrales de traitement d’air (CTA). Ce projet de thèse s’intéresse donc au devenir des microorganismes aérosolisés dans des filtres photocatalytiques. La première étape a consisté à étudier les mécanismes de dégradation par photochimie et photocatalyse d’une bactérie modèle, Escherichia coli (E. coli), en suspension dans l’eau sous irradiation UV-A ou UV-C. Ces deux traitements sont plus efficaces sous UV-C et engendrent des dommages oxydatifs au niveau de la membrane externe et des acides nucléiques bactériens. Le dosage de sous-produits chimiques permet de conclure que la photocatalyse UV-C est plus efficace pour dégrader irréversiblement les bactéries. La seconde étape a été consacrée à l’étude de l’inactivation de spores d’Aspergillus niger et de bactéries E. coli dans les filtres Ahlstrom. Nos résultats confirment l’intérêt d’utiliser des filtres photocatalytiques dans les CTA en comparaison avec les filtres non photocatalytiques. L’utilisation de filtres à haute efficacité, afin d’optimiser le temps de contact entre les microorganismes et le dépôt de dioxyde de titane, permet d’augmenter l’efficacité de dégradation du procédé photocatalytique / Indoor Air Quality (IAQ) has become of particular concern from an environmental and health and safety point of view. It is now proven that the presence of microorganisms in indoor air can have hazardous consequences on human health. HVAC systems, when poorly maintained, can themselves become source of bioaerosols when their filters are contaminated. To tackle this issue, photocatalytic filters have been developed and tested within HVAC systems. The aim of this PhD thesis is to look at the behaviour of microorganisms aerosolized through photocatalytic filters. The first step consisted of analysing the photochemistry and photocatalysis degradation mechanisms of a model bacterium, Escherichia coli (E. coli), in suspension in water under UV-A or UV-C radiation. These two treatments were proven to be more efficient under UV-C radiation and led to oxidative damages to outer membrane and nucleic acids. The measurement of chemical by-products allowed us to conclude that UV-C photocatalysis is more effective in damaging bacteria in an irreversible manner. The second step focused on the analysis of the inactivation of Aspergillus niger spores and E. coli bacteria within Ahlstrom filters. Our results confirm the benefits of using photocatalytic filters in HVAC systems instead of non-photocatalytic filters. The use of high efficiency filters to optimise the contact between the microorganisms and the titanium dioxide deposit, allows an increase in the damaging efficiency of the photocatalytic process

Please read the abstract in the section 00front of this document / Dissertation (MSc (Soil Science))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

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To mitigate the problems of depleting and soaring price of fossil fuels, the production and use of renewable energy have been vigorously promoted. In Europe, the role of biologically-derived fuels and in particular biodiesel is gradually increasing in prominent. Rapeseed biodiesel is the most widely produced in Europe. As a consequence, enormous amount of by-products from production processes are being generated. Current strategies for managing these by-products (mainly rapeseed meal and crude glycerol) seem not to be economically sustainable. More efficient utilisation could add more value to the production chain which in turn would raise the competitiveness of biodiesel compared to petro-diesel. The aim of the project reported in this thesis was to study the feasibility of producing a value added product, polyhydroxybutyrate (PHB), from by-products generated from rapeseed biodiesel production processes as well as to investigate the effects of methanol, a major impurity in crude glycerol, on growth of Cupriavidus necator, a PHB-producing micro-organism.The preliminary study of C. necator growth in crude glycerol based media revealed that optimum concentration of crude glycerol was in a range 15-25 g/L. It was also found that slight changes in the carbon to nitrogen ratio of the feedstock did not significantly affect the growth while methanol at concentrations beyond 10 g/L did. A model based on a saturation equation was developed and used to successfully predict the inhibition of growth by methanol. From the developed model, mechanisms of the inhibition were proposed. The model could also be used to predict satisfactorily growth or productivity rates in other systems containing short-chain alcohols. The growth in solutions derived from rapeseed meal (designated as hydrolysate) via solid-state fermentation by Aspergillus oryzae followed by hydrolysis of the fermented solids was also studied. The biomass production was found to increase as a function of initial free amino nitrogen (FAN) concentration presented in the hydrolysate. However, at higher initial FAN concentrations, a lower conversion of nitrogen to biomass was observed. PHB production was studied using a feedstock which was a mixture of the hydrolysate and crude glycerol. Total biomass concentration reached 28.8 g/L at 120 h with 86% PHB content. PHB productivity and PHB yield on glycerol were 0.21 g/L•h and 0.32 g/g respectively. These results were comparable with those obtained when pure glycerol and synthetic crude glycerol were used, suggesting that, technically, the use of the generic rapeseed- and crude glycerol-based feedstock to produce PHB is feasible.Overall, the feasibility of producing PHB from rapeseed biodiesel by-products has been demonstrated. The satisfactory result leads to the more important outlook that the generic feedstock derived from rapeseed biodiesel by-products has the potential to be used to produce a wide range of products depending on the micro-organism used. Further development of this process to improve nutrient production efficiency as well as product yields and subsequent integration of the process into the biodiesel production process could well be an important contribution in the development of a sustainable biodiesel industry.

Orientadores: Helena Teixeira Godoy, Isidro Hermosín-Gutiérrez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T07:59:41Z (GMT). No. of bitstreams: 1 Barcia_MileneTeixeira_D.pdf: 4811486 bytes, checksum: f7f9e34df585b2658347bb259cbf89e5 (MD5) Previous issue date: 2014 / Resumo: Bagaço (cascas e sementes) e borra (sedimentos sólidos) são os mais abundantes subprodutos do processo de vinificação, pois o primeiro representa aproximadamente 5% do total de uva processada e, o segundo, 4% do volume total de vinho produzido. Alguns estudos demonstraram que os resíduos vinícolas contêm importantes compostos fenólicos, potentes antioxidantes, que não foram totalmente transferidos ao vinho durante o processo de vinificação, assim despertando interesse econômico e funcional. Sendo assim, o objetivo deste trabalho foi caracterizar os compostos fenólicos de resíduos vinícolas, e correlacionar os seus teores com a capacidade antioxidante. Foi determinado o teor de compostos fenólicos das uvas in natura, do bagaço (casca e semente) e borras, obtidas em duas safras (2011 e 2012), das variedades BRS Violeta, BRS Lorena, Cabernet sauvignon e Cabernet franc, por SPE e HPLC-DAD-ESI MS/MS. Também foi avaliado o efeito de três técnicas de secagem aplicadas aos subprodutos da vinificação (bagaço e borra): secagem em estufa a 50 °C (D50), secagem por spray-drying (SP), e secagem por liofilização (FD), assim como a estabilidade dos subprodutos secos D50 e SP, submetidos a 25 °C durante 0, 30 e 90 dias. A capacidade antioxidante foi avaliada por ORAC, FRAP, ABTS e ß-caroteno/ácido linoleico, e suas correlações com antocianinas e fenólicos totais. Foram identificadas 25 antocianinas e 9 piranoatocianinas nas diferentes amostras analisadas. A composição de antocianinas de BRS Violeta foi principalmente pelos derivados diglicosídeos. No entanto, nas amostras de Cabernet sauvignon e Cabernet franc as antocinaninas majoritárias foram 3-glicosídeos. As piranoantocianinas foram encontradas somente em cascas fermentadas das cultivares Cabernet sauvignon e Cabernet franc e nas borras de todas as cultivares. Os flavonois encontrados foram principalmente, quercetina, isoramnetina, miricetina, laricitrina e siringetina. Nas uvas predominaram os glicosilados, e nos resíduos obtiveram maiores proporções de agliconas livres, especialmente nas borras de vinho (85%). Na BRS Lorena, quercetina foi o flavonol majoritário nas cascas (91%) e nas borras (95%). Já em todas as amostras de BRS Violeta, os derivados do ácido caféico foram predominantes. Os ácidos caftárico (53%) e cutárico (17%) foram superiores nas amostras das cultivares Cabernet sauvignon e Cabernet franc. Em todas as amostras de uvas e borras detectou-se a presença de trans-resveratrol, trans-piceid e cis-piceid (com exceção da BRS Violeta). Nos resíduos secos em estufa a 50°C e spray-drying observou-se uma redução de até 50% no teor de compostos fenólicos totais dos diferentes resíduos das quatro variedades de uva no tempo zero, quando comparado com o liofilizado. Em todos os métodos de capacidade antioxidante, as amostras BRS Violeta demonstraram valores superiores quando comparadas a BRS Lorena, Cabernet sauvignon e Cabernet franc. Os subprodutos da vinificação secos apresentaram concentração elevada de compostos fenólicos totais, em média os valores oscilaram de 810 à 8557 mg/kg para casca fermentada; de 1515 à 9520 mg/kg para semente; e 1148 à 4261 mg/kg para borra, nas cultivares estudadas. Nas uvas inteiras secas utilizadas no processamento do vinho o teor de compostos fenólicos encontrados foi de 530 à 4330 mg/kg. Sendo assim, os subprodutos analisados possuem elevado teor de compostos antioxidantes e, portanto, com potencial para reaproveitamento industrial / Abstract: Grape marc (skins and seeds) and lees (sediment solids) are the most abundant by-products of the winemaking process, because the first represents approximately 5% of the total grapes processed and the second, 4% of the total volume of wine produced. Some studies have shown that winery residues contain phenolic compounds, potent antioxidants that were not fully transferred to the wine during the winemaking process, thus with economic and functional interest. Thus, the objective of this work was characterize the phenolic compounds of industrials residues generated by the vinification and correlate their levels with the antioxidant capacity. The phenolic content of grapes in natura, grape marc (skins and seeds), and lees, in two consecutive years (2011 and 2012), of varieties BRS Violeta, BRS Lorena, Cabernet sauvignon and Cabernet franc, was determined by SPE and HPLC-DAD-ESI MS/MS. The effect of three drying techniques applied to vinification by-products (grape marc and lees) was also evaluated: dried at 50 °C, drying by spray-drying and freeze-drying, as well as the stability of by-products dried submited at 25°C in 0, 30 and 90 days. The antioxidant capacity was evaluated by ORAC, FRAP, ABTS and ß-caroteno/linoleic acid, and their correlations with total anthocyanins and phenolics. Were identified 25 anthocyanins and 9 piranoathocyanins in the samples analyzed. The composition of anthocyanins BRS Violeta was mainly derived by diglucosides. However, in samples of Cabernet sauvignon and Cabernet franc antocynanins 3-glucosides were majority. The pyranoanthocyanins were found only in fermented skins of the cultivars Cabernet sauvignon and Cabernet franc and the lees of all cultivars. Flavonols were found mainly quercetin, isorhamnetin, myricetin, laricitrin, and syringetin. In grape glycosides predominated, and residues were obtained higher proportions of free aglycones, especially the lees of wine (85%). In BRS Lorena, type flavonol quercetin was the majority in the skin (91%) and the lees (95%). Already in all samples BRS Violeta, derivatives of caffeic acid were predominant. The caftaric acids (53%) and coutaric acid (17%) were high in the samples of the cultivars Cabernet sauvignon and Cabernet franc. In all samples of grapes and lees were detected the presence of trans-resveratrol, trans-piceid and cis-piceid (except BRS Violeta). In the residue dried at 50 °C and spray-drying showed a 50% reduction in the total phenolic content of the residues of four different varieties of grape at time zero when compared to the lyophilized. In all methods of antioxidant capacity, BRS Violeta samples showed higher values when compared to BRS Lorena, Cabernet sauvignon and Cabernet franc. The byproducts of winemaking had elevated total phenolics, average values ranged from 810 to 8557 mg/kg for fermented skins; 1515 to 9520 mg/kg for seeds, and 1148 to 4261 mg/kg for lees. In grapes used in the processing of wine the phenolic content was found of 530 to 4330 mg/kg dried grape. Thus, the by-products have a high content of antioxidant compounds and therefore have the potential for industrial reuse / Doutorado / Ciência de Alimentos / Doutora em Ciência de Alimentos

Blood trihalomethanes (THMs) and urinary haloacetic acids (HAAs) are the leading candidate biomarkers for disinfection byproduct (DBP) exposure. However, no studies have assessed the exposure profiles, temporal variability, and potential predictors of these biomarkers during pregnancy. Here we collected blood (n = 4304) and urine samples (n = 4165) from 1760 Chinese pregnant women during early, mid-, and late pregnancy, which were separately analyzed for 4 THMs and 2 HAAs. We calculated the intraclass correlation coefficients (ICCs) to assess the variability of these biomarkers and estimated their correlations with sociodemographic, water-use behavioral, dietary and sample collection factors using mixed models. The median concentrations of TCM, BDCM, Br-THMs [sum of BDCM, dibromochloromethane (DBCM), bromoform (TBM)], total THMs (TTHMs, sum of TCM and Br-THMs), DCAA and TCAA in the water distribution system were 4.2 μg/L, 1.7 μg/L, 2.9 μg/L, 7.1 μg/L, 3.4 μg/L and 8.2 μg/L, respectively. Chloroform (TCM), bromodichloromethane (BDCM), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were detected in > 75% of the biospecimens. Repeated measurements of blood TCM, BDCM, Br-THMs and TTHMs and urinary DCAA and TCAA uniformly exhibited high variability (ICCs = 0.01–0.13); the use of a single measurement to classify gestational average exposure resulted in a high degree of exposure misclassification. The sampling season was a strong predictor of all analyzed DBPs. Additionally, we detected a positive association of blood TCM and BDCM with household income, urinary DCAA with age, and urinary TCAA with tap water usage, education level and amount of tap water consumed. Inverse associations were found between blood BDCM and vegetable consumption, and between blood Br-THM and TTHM and time interval since the last bathing/showering. Afternoon samples had lower DCAA concentrations than did early morning samples. Our results indicate that blood THM and urinary HAA concentrations vary greatly over the course of pregnancy and are affected by sampling season, time of day of blood/urine collection, sociodemographic factors, recent water-use activities and dietary intake.

A low-cost titanium production process, the CSIR-Ti powder process, which aims to produce titanium powder directly by metallothermic reduction of titanium tetrachloride with lithium, has been under development at the Council for Industrial and Scientific Research (CSIR). Crude titanium powder produced using the CSIR-Ti process is inevitably contaminated with by-products such as lithium chloride, lithium and titanium dichloride. These by-products tend to become sources of impurities in titanium powder, specifically oxygen and chloride impurities. The presence of oxygen and chloride impurities has marked effects on the mechanical properties of titanium finished products. Consequently, for the crude titanium powder to be rendered useful downstream, it must be purified and the by-products reduced to concentrations specified in the commercial standards. The present study was undertaken to examine whether acid leaching could be used to selectively dissolve and prevent hydrolysis of the by-products—specifically excess lithium and unreacted titanium dichloride in the crude titanium powder produced by the CSIR-Ti process. A further objective was to determine whether a purified product that meets both oxygen and total residual chloride content as specified by the standards can be achieved. The effects of key leaching variables and their interaction were also investigated to gain fundamental understanding of these effects on the by-products leaching behaviour. A literature study to select a suitable lixiviant and to establish the aqueous chemistry of the byproducts and their effect on the leaching conditions was undertaken. It showed that of the various acids suggested in the literature, hydrochloric acid was the cheapest and that it was more suited for the CSIR-Ti leaching process than nitric acid, due to the common ion chloride. This simplifies the leachate purification process downstream. The literature study established that Ti(II) has no aqueous chemistry but instead is oxidised to Ti(III) in solution. It was found that Ti(III) is easily oxidised to TiO2+ by dissolved oxygen and water. However, the oxidation rate was slow in hydrochloric acid solutions with the advantage that hydrolysis of the ions could be minimised and the precipitation of the oxides or oxychlorides prevented. It was further revealed that the lithium neutralisation reaction is highly exothermic, with the possibility of raising the leachate temperature to 60°C, resulting in the contamination of the titanium powder particles by the oxide layer and precipitated hydrolysis products. Batch leaching tests were carried out using factorial design of experiments to investigate the effect of initial hydrochloric acid concentration, which was estimated by varying the concentration between 0.032 M and 1 M; particle size, which was varied between −10 mm and +10 mm; and the initial temperature, varied between 14°C and 30°C. The resulting data were modelled and analysed using the analysis of variance statistical method. The solid residues were analysed for oxygen and total residual chloride content. The solid residue was also characterised by scanning electron microscopy (SEM) to examine the morphology of the leached particles. Leaching kinetics model fitting was also conducted. The statistical analysis showed that of the three factors investigated, temperature was the factor with the most statistical significance on both the oxygen and chloride concentration in the purified product, followed by particle size. The effect of acid concentration proved to be minimal, a phenomenon attributed to low concentrations of acid-consuming impurities, specifically excess lithium in the crude product. Thus, the two concentrations of hydrochloric acid investigated were found to be efficient to prevent hydrolysis product formation. Scanning electron micrographs revealed that crushing the crude product with a jaw crusher occluded crude titanium pores, thus locking in some by-products in addition to the pores locked by sintering during the metallothermic reduction. The observation showed that residual chloride impurities in the purified product are not just a consequence of hydrolysis products but also byproducts locked deeper in the pores of the product. Based on the parameter ranges evaluated in the study, a product that satisfied both oxygen and chloride standard specifications was achieved when the crude product was leached in both 1 M and 0.032 M initial HCl concentrations, temperature of 30°C and particle size of +10 mm. The combination of (−10 mm and 14°C) at all concentrations also yielded acceptable oxygen and chloride content levels. Overall, it was concluded from the present work that purification of crude CSIR-Ti product by leaching in dilute HCl is technically feasible. / Dissertation (MSc Applied Sciences (Metallurgy))--University of Pretoria, 2014. / Materials Science and Metallurgical Engineering / MSc (Applied Sciences (Metallurgy)) / Unrestricted

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18659号 / 農博第2088号 / 新制||農||1027(附属図書館) / 学位論文||H26||N4882(農学部図書室) / 31573 / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 廣岡 博之, 教授 松井 徹, 教授 久米 新一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

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