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.

Acyl-CoA binding protein (ACBP) ubiquitously found in eukaryotic organisms fulfills important functions of solubilisation, protection and transport of acyl-CoA esters, a major intermediate of lipid metabolism. This thesis presents an investigation of the physiological role of the small cytosolic ACBP in seed oil biosynthesis. The second important objective of this study was to evaluate the use of ACBP as a molecular tool for modification of seed oil content and/or fatty acid (FA) composition. Agrobacterium-mediated transformation of Arabidopsis thaliana and Brassica napus was performed with a number of genetic constructs designed for seed-specific expression of the B. napus cDNA encoding a small cytosolic ACBP. Protein level and subcellular localization of BnACBP in A. thaliana transgenic seeds depended on the structure of the genetic constructs mainly, the presence of additional in-frame sequences, encoding a protein fusion partners or signal peptides. Seed oil from A. thaliana T2 and T3 seeds had increased polyunsaturated fatty acid (PUFA) percentage (18:2cis delta9,12 and, in some lines, 18:3cis delta9,12,15) at the expense of very-long-chain monounsaturated (20:1cis delta11) and saturated (18:0) fatty acids. An increase in PUFA levels in seed oil was due to enhanced acyl channeling from the acyl-CoA pool to phosphatidylcholine, the substrate for extraplastidial FA desaturation. The activity of A. thaliana acyl-CoA: lysophosphatidylcholine acyltransferase (AthLPCAT), an enzyme involved in acyl exchange between acyl-CoA and PC, was significantly increased in the presence of the recombinant B. napus ACBP (rBnACBP) in the reaction mixture. rBnACBP also modulated enzymatic activities of glycerol-3-phosphate acyltransferase and diacylglycerol acyltransferase in vitro. Finally, the effect of constitutive or seed-specific gene silencing of ACBP on seed oil formation was examined. A. thaliana transformation with RNAi constructs resulted in partial suppression of ACBP expression and changes in FA composition of seed oil which included an increase in the percentage of 18:1cis delta9 and 18:2cis delta9,12 and, decrease of 18:3cis delta9,12,15. Overall, the results of this study demonstrate that the small cytosolic ACBP plays an important role in acyl exchange between acyl-CoA and PC metabolic pools. Overexpression of ACBP during seed development can be useful in genetic engineering strategies aimed at modifying the FA composition of seed oils. / Plant Science

Sorghum is a valuable grain crop and a principle source of food of particular importance in human and animal nutrition in the semi-arid regions of Africa and Asia. Despite its value, sorghum grain quality is a major limitation to its productivity and profitability. Sorghum grain is usually discounted as feed grain when compared to wheat and barley, predominantly because of its poor digestibility. The sorghum endosperm is composed of a complex starch protein matrix, whereby the starch is physically bound within the storage proteins, the kafirins. The kafirins are synthesised on the membrane bound polysomes and have a signal peptide which targets them to the lumen of the endoplasmic reticulum. Growth of protein bodies occur as - kafirins fill in the interior with  and γ kafirins occupy the periphery. Despite the -kafirins being more digestible and composing of 60- 80% of the kafirins, they are not easily accessible due to  and γ kafirins which have a high content of intermolecular disulphide bonds (S-S), rendering them highly resistant to proteases. Alteration of the structure of the protein bodies and change of the location of the-kafirins could result in a higher digestibility of sorghum proteins. This could be achieved by upregulating or downregulating the -kafirins. The improvement of grain quality, both in increased protein and starch digestibility would substantially enhance the digestibility of sorghum as animal feed as well as for human consumption. Various techniques have been utilised to classify the kafirins according to their mobility on SDS PAGE electrophoresis, Reverse Phase High Performance Liquid Chromatography (RP-HPLC), Free Zone Capillary Electrophoresis (FZCE) and Lab on Chip. Until recently the characterisation and classification of the kafirins generally have relied on the characterisation of zeins from maize. Zeins have about 70% homology to the kafirins both at the nucleotide and amino acid level. Based on the high similarity of the -kafirins to the -zeins, the - kafirins have been classified as 19 and 22 kDa. Despite their 70% homology the migration of the - kafirins on SDS PAGE is quite different to that of the zeins. Hence, I propose a new classification of the -kafirins as 23 kDa and 25 kDa based on their mobility on SDS PAGE Characterisation and cloning of the 23 and 25 kDa genes was performed using QL41 the Queensland inbred line of sorghum. Ten positive clones were isolated from a cDNA library for the 25 kDa and two clones for the 23 kDa -kafirins. The isolated clones of the 25 kDa -kafirins showed 98-99% homology with each other and also with the GenBank sequences. The major finding was the characterisation of the 23 kDa -kafirins. The two clones obtained showed 100% homology to each other as well as to the published sequences on the GenBank, and were full-length sequences. Also a partial sequence was obtained that lacked the signal peptide and was different to the other two clones. Whilst characterising the 23 kDa a second group of the 25 kDa -kafirins was identified from the genomic DNA, of all the three genotypes (QL41, 296B and QL12), which was unique from the previously isolated clones. This group of -kafirins was not among the cluster but was 5’ upstream of the cluster. This group had a higher content of the glutamine compared with the other 25 kDa group. The expression level was studied to show how each gene family contributed to the level of - kafirins. QL41 and 296B were used for this study. From the studies it was shown that the 23 kDa - kafirins genes were 20% more expressed than the 25 kDa. An attempt to identify suitable markers for the -kafirins was investigated using RFLP and SSR analysis. Thirty-two different genotypes were utilised for this study. The observed variation indicated by cluster analysis (4-38%) clearly showed variation of the -kafirins in genotype and within the kafirin genes as elucidated by the sequences in Chapter 4. Markers able to identify this variation could help in the selection of highly digestible mutants. Hence, there is potential for sorghum grain improvement using marker-assisted breeding. The need to identify a tissue specific promoter was essential, especially for a strong promoter that could drive expression in the endosperm of the monocots. A vector construct consisting of the - kafirin promoter driving the GUS reporter genes was used for transient expression from QL41. This was assessed in the sorghum and barley calli, sorghum endosperm and leaves and corn endosperm. Tissue specific expression as well as higher levels of transient expression were seen using the - kafirin promoter, compared with the ubiquitin promoter. Preliminary experiments have illustrated the potential use of a gene silencing mechanism that could enhance the digestibility of sorghum grain. The 25 kDa -kafirin gene was used as the target for gene silencing using the mechanism of iRNA. Transformation constructs were developed using the throughput vector pSTARGATE in an effort to silence the 25 kDa -kafirins. The characterisation of the -kafirins has provided valuable information for future sorghum improvement research.

Bibliography: p. 182-197. / xxii, 197 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The objectives of this study are: selection and construction of four narrow sowing points, evaluation of these points in terms of draught requirements and wear rates, comparison of the points in direct drilling systems and their effects on soil physical properties. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy & Farming Systems (Agricultural Technology), 1997

Orobanche ramosa L. is an annual, parasitic weed present in the western Murray-Mallee region of South Australia. A quarantine zone was established to encompass all known infestations, and has been adjusted over time as new infestations have been discovered. The movement of fodder, machinery, grain and straw, horticultural crops, livestock, and soil is controlled by strict quarantine procedures, to prevent further spread across the landscape. O. ramosa presents a unique situation for weed managers: plants are obligate parasites, relying entirely on broadleaved hosts for their water and nutrition; and seeds are tiny (0.3 mm), produced in large numbers (up to 100 000 seeds per plant), and are long-lived, persisting in the soil seed bank for up to 13 years. The dispersal vectors for O. ramosa in South Australia are the focus of this Master’s thesis. Two dispersal vectors were chosen for investigation: sheep and wind. Sheep were examined as possible vector for seeds, both via the gut (internal transport, or endozoochory) and via adhesion on the external surface of the animal (external transport, or epizoochory). Internal transport via sheep was investigated with a classic gut-passage experiment, which showed a peak in excretion of weed seeds at day 2, reducing to zero seeds excreted at day 8, and a half-life of 2 days. Two phases of external transport on sheep was studied: attachment and retention. Attachment was confirmed by finding seeds on the body wool and feet of sheep that had been kept for 7 days on soil with an O. ramosa seedbank. Seed retention was confirmed by placing seeds onto the body and still finding them in wool samples after 7 days. Wind was the other dispersal vector investigated for O. ramosa. A survey of natural wind dispersal was conducted, which confirmed wind as a vector and allowed trap design to be tested. Then a portable field-based wind tunnel was used to investigate the effects of ground cover (bare ground and cereal stubble) and wind speed (low, medium and high) on wind dispersal of O. ramosa seeds. For the stubble treatments, more seeds were trapped within the tunnel, and on bare ground more seeds were trapped exiting the tunnel. Importantly, the data showed that low wind speeds readily move O. ramosa seeds, and that the seeds are capable of aerodynamic lift in the wind profile. Results are discussed in the context of dispersal biology, quarantine procedures, and future work that would further refine knowledge of likely dispersal vectors for O. ramosa. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1459246 / Thesis (M.Sc.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009

Exclosure plots were monitored to investigate the impact of browsing on seedling recruitment by Trichosurus vulpecula, Oryctolagus cuniculus and Rattus rattus on seedlings under Leptospermum scoparium and Kunzea ericoides plantings in two Auckland Regional Council Parks (ARC), Shakespear and Wenderholm. The number of woody seedlings that established over a 17-month period was recorded. Gaps within the same Leptospermum scoparium and Kunzea ericoides canopy were created to investigate the influence of the canopy on seedling recruitment. Soil samples were taken to investigate the existing seed bank beneath the same Leptospermum scoparium and Kunzea ericoides canopies.At Wenderholm, net change in seedling density differed among treatments (P=0.014). Seedling density increased within the plots that excluded Trichosurus vulpecula and Oryctolagus cuniculus and within plots that additionally excluded Rattus rattus, but declined in the control plots. In contrast at Shakespear, although seedling density increased more within both the exclosure plots than in the control plots, this result was not statistically significant (P=0.728). At Wenderholm, the average seedling height increased within both types of exclosure plots, but declined in the control plots. However, these differences among treatments were not statistically significant (P=0.204). At Shakespear, seedlings increased in height within the Trichosurus vulpecula, Oryctolagus cuniculus and Rattus rattus exclosures and declined marginally in the other two treatments. Again, differences in height change among treatments were not statistically significant (P=0.202).At both regional parks, the greatest cause of mortality within the exclosures excluding Trichosurus vulpecula and Oryctolagus cuniculus was desiccation. All of the mortalities within the Trichosurus vulpecula, Oryctolagus cuniculus and Rattus rattus exclosures was unidentifiable. However, within the control plots, at Wenderholm, the greatest identified cause of mortality was browsing and at Shakespear, the only cause of mortality within the control plots was browsing.Seedbanks at Wenderholm and Shakespear under the Leptospermum scoparium and Kunzea ericoides plantings were dominated by forb species. A total of 1308 seedlings germinated from soil taken from Wenderholm, with exotic species making up 99.4% of germinations, with exotic species making up 97.9% of germinations. Similarly a total of 801 seedlings germinated from soil samples taken from Shakespear.At Wenderholm, the number of native seedling germinations within the gaps created in the Leptospermum scoparium and Kunzea ericoides canopy, was more than twice the number that germinated under the closed canopy. However, this difference was marginally non-significant (P=0.065). At Shakespear, the number of native seedling germinations within gaps created in the Leptospermum scoparium and Kunzea ericoides canopy was similar to the number that germinated under the closed canopy (P=0.2603).The results suggest that at Wenderholm, despite ongoing predator control, Trichosurus vulpecula and/or Oryctolagus cuniculus have had an adverse effect on the survival and growth of seedlings. The results also suggest that at Shakespear, Rattus rattus have had an adverse effect on the survival and growth of seedlings under the Leptospermum scoparium and Kunzea ericoides canopy. The distance from mature forest may also have had an impact on the dispersal of native seeds within the Leptospermum scoparium and Kunzea ericoides canopy. The implication of these results for the future management of restoration plantings in regional parks is discussed.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 139-148).

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Thesis(Ph.D.)--University of Western Australia, 2006.

Thesis (M.Sc.(Zoology and Entomology))--University of Pretoria, 2008. / Summary in English. Includes bibliographical references.