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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

BIODIESEL PRODUCTION USING SUPPORTED 12-TUNGSTOPHOSPHORIC ACID AS SOLID ACID CATALYSTS

2014 December 1900 (has links)
Biodiesel has achieved worldwide recognition for many years due to its renewability, lubricating property, and environmental benefits. The abstract represents a summary of all the chapters of the thesis. The research chapters are defined as research phases in the abstract. The thesis starts with an introduction followed by literature review. In the literature review, all the necessary data were collected reviewing the literature. Then an artificial neural network model (ANN) was built based on the published research data to capture the general trends or to make predictions. Both catalyst properties and reaction conditions were trended and predicted using the network model. The review study revealed that esterification and transesterification required catalysts with slightly different properties. In the first phase of the study, biodiesel production using 12-Tungstophosphric acid (TPA) supported on SBA-15 as a solid acid catalyst was studied. In this phase of the study, a large number of 0-35% TPA on SBA-15 catalysts were synthesized by impregnation method and the effects of various operating conditions such as–catalyst wt.% and methanol to oil molar ratio on the transesterification of model feedstock Triolein were studied. A 25% TPA loading was found to be the optimum. A 4.15 wt.% catalysts (based on Triolein) and 39:1 methanol to Triolein molar ratio was found to be the optimum reaction parameter combination, when the reaction temperature was kept fixed at 200C, stirring speed of 600 rpm and 10 h reaction time. The biodiesel yield obtained using this condition was 97.2%. In the second phase of the study, a 12-Tungstophosphoric acid (TPA) was supported by using organic functional group (i.e. 3-aminopropyltriethoxysilane (APTES)) and was incorporated into the SBA-15 structure. A 45 wt.% TPA incorporated SBA-15 produced an ester with biodiesel yield of 97.3 wt.%, when 3 wt.% catalyst (based on the green seed canola (GSC) oil) and 25.8:1 methanol GSC oil molar ratio were used at 2000C for reaction time of 6.2 h. In the third phase, process sustainability (i.e. process economics, process safety, energy efficiency, environmental impact assessment) studies were conducted based on the results obtained in phase three. Based on the study, it was concluded that heterogeneous acid catalyzed process had higher profitability as compared to the homogeneous acid catalyzed process. Additionally, it was obtained that heterogeneous acid catalyzed process was safe, more energy efficient and more environment friendly than homogenous process. In the fourth phase, the catalytic activity of Tungsten oxide (WO3) and TPA supported (by impregnation) on H-Y, H-β and H-ZSM-5 zeolite catalysts were tested for biodiesel production from Green Seed Canola (GSC) oil. In this phase of the study, TPA/H-Y and TPA/H- zeolite were proved to be effective catalysts for esterification and transesterification, respectively. A 55% TPA/H- showed balanced catalytic activity for both esterification and transesterification. It yielded 99.3 wt.% ester, when 3.3 wt.% catalyst (based on GSC oil) and 21.3:1 methanol to GSC oil molar ratio were used at 200C, reaction pressure of 4.14 MPa and reaction time of 6.5 h. Additionally, this catalyst (55% TPA/H-) was experimented for etherification of pure glycerol, and maximum conversion of glycerol (100%) was achieved in 5 h at 120C, 1 MPa, 1:5 molar ratio (glycerol: (tert-butanol) TBA), 2.5% (w/v) catalyst loading. Later, these conditions were used to produce glycerol ether successfully from the glycerol derived after transesterification of green seed canola oil. A mixture of GSC derived biodiesel, and glycerol ether was defined as biofuels. In the fifth phase, catalytic activity of H-Y supported TPA (using different impregnation methods) was studied in details further for esterification of free fatty acid (FFA) of GSC oil. From the optimization study, 97.2% FFA (present in the GSC oil) conversion was achieved using 13.3 wt.% catalyst, 26:1 methanol to FFA molar ratio at 120°C reaction temperature and 7.5 h of reaction time.In the sixth- and final phase, techno-economic and ecological impacts were compared between biodiesel and combined biofuel production processes based on the results obtained in phase four. Based on the study, it was concluded that, biodiesel production process had higher profitability as compared to that for combined biofuel production process. Additionally, biodiesel production process was more energy efficient than combined biofuel production process. However, combined biofuel production process was more environment-friendly as compared to that for biodiesel production process.
2

Green seed coat colour retention in lentil (<i>lens culinaris</i>)

Davey, Blaine Frederic 13 December 2007
Poor seed coat colour desirability in green lentil (<i>Lens culinaris</i>) costs lentil producers millions of dollars each year. The monetary value that Canadian lentil producers receive for their crop is based on the visual characteristics of the seed coat, mainly the colour. Higher value is given for samples described to have more desirable green seed coat colour. A breeding line, 1294M-23, has been noticed to consistently produce more desirable green lentil samples.<p>A cross was made between 1294M-23 and a less desirable breeding line 1048-8R with the goal of studying the heritability of green seed coat desirability measured by the Acurum® machine. The resulting progeny were taken to F7 by single seed descent. In 2005 and 2006 the recombinant inbred lines (RILs) were seeded in a randomized complete block design at three sites in the current main lentil growing region of Saskatchewan. To measure the seed coat colour of the samples, the Acurum® machine, which is a colour analyzing machine developed for grain crops, was used to consistently compare the samples. The study illustrated that the trait has large environmental effects and is quantitative with a high broad sense heritability of 0.82, using this specific cross and environments. Transgressive segregation occurred for RILs that had more desirable green seed coats and lower index scores than the desirable parent, 1294M-23. A tester that included all registered green lentil cultivars set was grown with the RILs in all environments. The seed coat colour index scores of the tester set fit into a small section of the range of index scores. They all had relatively high mean index scores, meaning less desirable, showing little genetic variation for the trait in current Canadian green lentil cultivars. <p>Chlorophyll was extracted from seed coats of some of the RILs. The amount of total chlorophyll, chlorophyll a, and chlorophyll b was compared to the Acurum® scores using regression analysis. The study found that there was significant relationship between chlorophyll a and b content and the index score, explaining 32 and 37 percent of the variation, respectively. <p>Another portion of the study was to determine if preharvest treatment of the green lentil crop has an effect on the green seed coat colour of the sample. A set of genotypes consisting of all registered green seed coat cultivars was grown at two locations in Saskatchewan in both 2005 and 2006. Prior to harvest a plot of each genotype was swathed, and a second plot was desiccated with diquat. After harvest the samples were analyzed for green seed coat colour using the Acurum® machine. In general, across most genotypes, sites, and years, swathing produced a significantly more desirable green lentil sample. The desirable green parent from the RILs, 1294M-23 produced the most desirable green lentil sample in this study. When the maturity rating was correlated to the Acurum® score a significant positive relationship was found in 2005 but not in 2006. This showed that lines with later maturity could be associated with more desirable green seed coat colour in some environments. Thus caution must be taken when selecting for more desirable phenotypes that genetic gains are being made rather than indirect selection for longer maturity.
3

Green seed coat colour retention in lentil (<i>lens culinaris</i>)

Davey, Blaine Frederic 13 December 2007 (has links)
Poor seed coat colour desirability in green lentil (<i>Lens culinaris</i>) costs lentil producers millions of dollars each year. The monetary value that Canadian lentil producers receive for their crop is based on the visual characteristics of the seed coat, mainly the colour. Higher value is given for samples described to have more desirable green seed coat colour. A breeding line, 1294M-23, has been noticed to consistently produce more desirable green lentil samples.<p>A cross was made between 1294M-23 and a less desirable breeding line 1048-8R with the goal of studying the heritability of green seed coat desirability measured by the Acurum® machine. The resulting progeny were taken to F7 by single seed descent. In 2005 and 2006 the recombinant inbred lines (RILs) were seeded in a randomized complete block design at three sites in the current main lentil growing region of Saskatchewan. To measure the seed coat colour of the samples, the Acurum® machine, which is a colour analyzing machine developed for grain crops, was used to consistently compare the samples. The study illustrated that the trait has large environmental effects and is quantitative with a high broad sense heritability of 0.82, using this specific cross and environments. Transgressive segregation occurred for RILs that had more desirable green seed coats and lower index scores than the desirable parent, 1294M-23. A tester that included all registered green lentil cultivars set was grown with the RILs in all environments. The seed coat colour index scores of the tester set fit into a small section of the range of index scores. They all had relatively high mean index scores, meaning less desirable, showing little genetic variation for the trait in current Canadian green lentil cultivars. <p>Chlorophyll was extracted from seed coats of some of the RILs. The amount of total chlorophyll, chlorophyll a, and chlorophyll b was compared to the Acurum® scores using regression analysis. The study found that there was significant relationship between chlorophyll a and b content and the index score, explaining 32 and 37 percent of the variation, respectively. <p>Another portion of the study was to determine if preharvest treatment of the green lentil crop has an effect on the green seed coat colour of the sample. A set of genotypes consisting of all registered green seed coat cultivars was grown at two locations in Saskatchewan in both 2005 and 2006. Prior to harvest a plot of each genotype was swathed, and a second plot was desiccated with diquat. After harvest the samples were analyzed for green seed coat colour using the Acurum® machine. In general, across most genotypes, sites, and years, swathing produced a significantly more desirable green lentil sample. The desirable green parent from the RILs, 1294M-23 produced the most desirable green lentil sample in this study. When the maturity rating was correlated to the Acurum® score a significant positive relationship was found in 2005 but not in 2006. This showed that lines with later maturity could be associated with more desirable green seed coat colour in some environments. Thus caution must be taken when selecting for more desirable phenotypes that genetic gains are being made rather than indirect selection for longer maturity.
4

Efeitos de diferentes percentuais de sementes esverdeadas na qualidade fisiológica de lotes de sementes de soja / Effects of different percentage of green seed physiological quality of soybean seeds lots

Arruda, Marcia Helena Mota de 06 December 2013 (has links)
Made available in DSpace on 2014-08-20T13:44:36Z (GMT). No. of bitstreams: 1 dissertacao_marcia_helena_mota_de_arruda.pdf: 305088 bytes, checksum: 0a5ff9434493f66e06397322e373ca1a (MD5) Previous issue date: 2013-12-06 / Brazil increased 9 % the production of soybeans during 2012/2013 crop. Since 2006, the state of Tocantins grow soybeans during a period called sanitary empty as exceptionalism. This production is destined for research or for seed. However, frequentlly, it was observed the presence of green seed at harvest. This release to produce soybean seed during sanitary empty, issued by the Ministry of Agriculture, Livestock and Supply, is due to climate and land conditions found in the municipalities of Lagoa da Confusão, Dueré and Formoso do Araguaia. This study was conducted to evaluate the effect of the occurrence in quality of green seeds in soybean seed lots. Four lots of the cultivar M-SOY 8866, medium cycle, produced in Formoso do Araguaia, state of Tocantins (TO) were used in this study. The lots were selected by visual presence of green seed with a 6X magnifying glass. The lots showed 17 %, 36 %, 49 % green seeds and were named respectively Lot 1, 2, 3 and control (lot with no green seeds). Seed quality was monitored through the thousand seed weight, germination in rolled paper with and without preconditioning, the tetrazolium test and the emergency field tests. The experimental design was a randomized complete block design with four seed lots and five replicates and the averages compared by Tukey test at 5 %. The results show a decrease in the percentage of germination and vigor in all plots when compared to the test, observed primarily by moisture damage in the tetrazolium, field emergence and germination test preconditioning 24 h test. / O Brasil, na safra 2012/2013, aumentou 9% a produção de sementes de soja. Desde 2006, o estado do Tocantins pratica a excepcionalidade de cultivar soja no Vazio Sanitário, sendo a produção destinada para pesquisa ou para semente. Porém, de forma frequente, observa-se a presença de sementes esverdeadas no momento da colheita. Esta liberação para produzir semente de soja durante o período de vazio sanitário, concedida pelo Ministério da Agricultura Pecuária e Abastecimento, deve-se às condições climáticas e territoriais encontradas nos municípios de Lagoa da Confusão, Dueré e Formoso do Araguaia. Este trabalho foi conduzido com o objetivo de avaliar o efeito da ocorrência de sementes verdes na qualidade de lotes de semente de soja. Foram utilizados quatro lotes da cultivar M-SOY 8866, ciclo médio, produzido em Formoso do Araguaia, estado do Tocantins (TO). Os lotes foram selecionados por presença visual de sementes esverdeadas, com o auxílio de lupa de seis aumentos, os quais apresentaram 17%, 36%, 49% de sementes verdes e foram denominados respectivamente de Lote 1, 2, 3 e uma testemunha (lote com ausência de sementes verdes). A qualidade das sementes foi monitorada através dos testes de peso de mil sementes, germinação em rolo de papel com e sem pré-condicionamento, teste de tetrazólio e emergência a campo. O delineamento experimental utilizado foi de blocos casualizados com quatro lotes de sementes e cinco repetições e as médias comparadas pelo teste de Tukey a 5%. Os resultados obtidos demonstram decréscimo no percentual de germinação e vigor em todos os lotes, quando comparados a testemunha, observado principalmente pelos danos de umidade no teste de tetrazólio, emergência a campo e teste de germinação com pré-condicionamento de 24 h.
5

Analysis of proteins involved in chlorophyll catabolism

Damaraju, Sridevi 18 May 2011 (has links)
Der Abbau des Chlorophyll (Chl) ist ein Prozess, der typischerweise während der Blattseneszenz und der Reifung von Früchten und Samen stattfindet. Eine Störung dieses koordinierten Prozesses unter Frostbedingungen verzögert den Chl-Abbau und ist ein grosses Hindernis bei der Herstellung von hochwertigem Rapsöl. Der Abbau von Chl zu farblosen Kataboliten erfolgt in einer Serie von enzymatischen Schritten und wird durch die Chlorophyllase begonnen (Chlase). Es wurde vorgeschlagen, dass ein wasserlösliches Chl Protein (WSCP) den Transport des Chl von der Thylakoidmembran zum Wirkort der Chlase übernimmt. Weiterhin wurde angenommen, dass die Steigerungen der Genexpressionen dieser frühen Schritte den Prozess des Chl-Abbaus beschleunigen. In der vorliegenden Arbeit werden die Auswirkungen der Überexpression der Chlase aus Citrus clementii (CcCHLASE) und von WSCP aus Blumenkohl (Cau-WSCP) in transgenen Tabakpflanzen analysiert. Dazu wurde die cDNA Sequenz der CcCHLASE in E. coli exprimiert und mittels in vitro Experimenten die Hydrolysierung von Chl durch die Chlase bestätigt. Anschließend wurden CcCHLASE exprimierende Tabakmutanten generiert und drei T1-Linien wurden unter verschiedenen Stress- und Seneszenzbedingungen untersucht. Die Chlase überexprimierenden Linien zeigten unter allen getesteten Bedingungen einen im Vergleich zum Wildtyp erhöhten Chlide a Gehalt. Trotzdem unterschied sich die Menge an Endkataboliten in diesen Mutanten nicht vom Wildtyp. Andererseits zeigten WSCP überexprimierende Linien zwar keine erhöhten Chlide a Gehalte jedoch erhöhte Protochlorophyllid-(Pchlide)-Level. Das deutet auf eine Rolle des WSCP als Speichermolekül für Chlorophyllvorstufen hin. Die photoprotektive Funktion des WSCP wurde zusätzlich in WSCP überexprimierenden Linien bestätigt. Diese zeigen im Vergleich zu Wildtyp-Tabakpflanzen auch bei hohen Lichtintensitäten von 700 – 900 µmol Photonen m-2 s-1 verringerte Gehalte an Zeaxanthin und reduzierte Peroxidaseaktivitäten. / Chlorophyll (Chl) catabolism is characteristically seen during leaf senescence, fruit ripening and seed maturation. Disruption of this coordinated process under frost conditions delays Chl breakdown and is a great concern in rapeseed oil production. The present work addresses this problem by studying the effect of enhanced Chl catabolism in genetically modified tobacco plants. Chl is catabolised to colourless catabolites through a series of enzymatic reactions initiated by Chlorophyllase (Chlase). A water soluble chlorophyll protein (WSCP) has been proposed to transport Chl from thylakoid membranes to the site of action of Chlase. It was assumed that enhancing the gene expression of these early events in Chl catabolism would increase the Chl breakdown process. The present work analysed the overexpression of Chlase from Citrus clementii (CcCHLASE) and WSCP gene from cauliflower (Cau-WSCP) in modified tobacco plants. Initially, the cDNA sequence of CcCHLASE was expressed in E. coli and in vitro tests confirmed the hydrolytic activity of Chlase on Chl. Subsequently, tobacco plants overexpressing CcCHLASE were generated and three T1 lines were analysed at various stress and senescence conditions. The in vivo production of Chlorophyllide (Chlide) indicated the extent of increased Chl breakdown. The Chlase overexpressor lines showed higher Chlide a steady state levels under all tested conditions in comparison to the WT tobacco plants. However, the end catabolites did not show much difference from WT plants. On the other hand, WSCP overexpressor lines did not show any increase in Chlide a levels, but demonstrated an increased protochlorophyllide (Pchlide) levels. This suggested the role of WSCP as a storage molecule of Chl precursors. Additionally, photoprotective function of WSCP was confirmed in WSCP overexpressors, by lower zeaxanthin levels and peroxidase activity even at high light intensities of 700 – 900 µmol photons m-2 s-1 in comparison to the WT tobacco plants.

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