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Despoulain, Béatrice. "Enrichissement des drèches blanches de maïs par les champignons filamenteux." Université Joseph Fourier (Grenoble), 1991. http://www.theses.fr/1991GRE18005.
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Gaillard, Sylvie. "Changements techniques et industrialisation capitaliste de la culture du mais en france depuis 1945 : elements pour une approche systemique." Lyon 2, 1986. http://www.theses.fr/1986LYO22006.
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Cette these est une tentative pour articuler la dynamique des systemes techniques et le processus d'industrialisation de l'agriculture, a partir de l'etude des caracteristiques particulieres du systeme de production du mais. Nous essayons de repondre a des questions concernant la genese, le fonctionnement et les limites du processus d'industrialisation de la culture du mais. Deux corps de l'analyse economique, a savoir l'economie des changements technologiques et l'economie rurale, viennent ici se conjuguer afin de rendre compte de la place de la dynamique de la technique dans les transformations des systemes de production agricoles. Le processus d'industrialisation de la culture du mais est un ensemble complexe, compose de plusieurs niveaux d'apprehension. Les deux premieres parties eclairent chacune un de ces niveaux : nous procedons d'abord a une analyse technique, puis economique. Mais si au terme de ces deux parties nous avons degage un ensemble de phenomenes, leur analyse demeure insatisfaisante. Les structures, technique et economique, sont les elements d'un systeme plus vaste dont la dynamique est le produit des inter-relations qui s'y etablissent. La derniere partie se donne pour objectif de presenter des elements pour une approche systemique de l'industrialisation de la culture du mais. Les phases de croissance et de crise du systeme de production du mais peuvent etre eclairees par une analyse en termes de coherence des systemes technique et economique, et de rupture de coherenceThis thesis is a tentative to articulate the dynamic of technical systems and the agricultural industrialization process, from the study of corn cultivation system. We try to answer questions about genesis, functioning and limits of the industrialization process of corn cultivation. Two analytic corpus, the technological change economy and the rural economy, are calling together to understand which is the place of technological dynamic in the change of agricultural production systems. Industrialization process of corn cultivation is a complex whole, composed of several apprehension levels. The first two parts throw light on one level : we are doing initially a technical analysis, then an economical one. Technical and economical structures are the elements of a vaster system, which dynamic is the product of relationships in this system. The aim of the last part is to introduce some elements for a systemic approach of corn cultivation industrialization. Growth and crisis of corn production system may be clarify by an analysis in terms of coherence and ruoture of coherence
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Bily, Antoine. "Rôle et importance des déhydrodimères d'acide férulique et autres phénylpropanoi͏̈des dans les mécanismes de résistance de Zea mays L. à Fusarium graminéarum Schwabe." Pau, 2003. http://www.theses.fr/2003PAUU3003.
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Fusarium graminearum est responsable d'une pathologie majeure du mai͏̈s. Le but de cette de thèse a été de comprendre les mécanismes de résistance variétale impliquant les phénylpropanoi͏̈des, métabolites secondaires du mai͏̈s. Des méthodes LC/MS ont été développées pour analyser le contenu de nombreux échantillons en phénylpropanoi͏̈des et mycotoxines. La production de trichothécènes par F. Graminearum est influencée par la nature des tissus du grain de mai͏̈s et leur composition en composés phénoliques. Les déhydrodimères d'acide férulique (DFA) sont des acteurs importants de la résistance variétale : un phénomène de dimérisation des résidus féruloyl de la paroi se produit dans les tissus externes des grains infectés d'une lignée résistante. A la récolte, les niveaux de DFA sont corrélés avec la résistance. Les cartographies QTL des phénylpropanoi͏̈des de la paroi et de la résistance à la fusariose indique un déterminisme génétique de l'implication des DFA dans la résistance à la fusarioseFusarium graminearum is responsible for a major maize disease. The objective of this thesis was to understand the mechanisms of varietal resistance, implicating some maize phytochemicals, the phenylpropanoids. LC/MS assays were developed for the analysis the phenylpropanoids and mycotoxins content of large numbers of samples. Trichothecene production is significantly affected by grain fractions and their phenolic content. Dehydrodimers of ferulic acid (DFA) play a role in varietal resistance: a dimerisation process of the cell wall bound feruloyl residues occurs in pericarp and aleurone infected tissues of the resistant line. At harvesting time, DFA contents are correlated with resistance. QTL mapping of cell wall phenylpropanoids and resistance to F. Graminearum indicates the genetic basis of the involvement of DFA in resistance
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Longchamps, Louis. "Discrimination entre le maïs et les mauvaises herbes par la signature spectrale de fluorescence induite par UV." Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23931/23931.pdf.
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Foyer, Jean. "Diversité naturelle et culturelle face aux défis des biotechnologies : enjeux et controverses au Mexique." Phd thesis, Université de la Sorbonne nouvelle - Paris III, 2008. http://tel.archives-ouvertes.fr/tel-00545542.
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Au Mexique et au niveau mondial, la protection de la diversité biologique et la défense de la diversité culturelle se sont constituées en enjeu de société ces trente dernières années, au moment où les biotechnologies s'imposaient comme une avancée technoscientifique à même de bouleverser notre rapport au vivant et de générer un important débouché commercial. Les controverses autour de la bioprospection et du maïs transgéniques, dans le contexte d'un pays qui présente une biodiversité exceptionnelle et la plus importante population indigène du continent américain, nous permettent de mettre en lumière comment, à travers elles, se confrontent des conceptions et des pratiques antagonistes de la connaissance, de la propriété, de l'agriculture, du développement, de la globalisation ou encore de l'environnement. Ces controverses sont donc globales au sens où, en arrière-plan des questions spécifiques et techniques qu'elles soulèvent, elles cristallisent toute une série de grands enjeux sociaux et environnementaux contemporains, dans un espace qui s'étire du local au mondial. Au-delà même des croisements de tous ces enjeux, les controverses semblent révéler un conflit beaucoup plus fondamental quant aux évolutions d'une modernité travaillée par le processus de globalisation et la remise en cause du clivage entre nature et société. L'opposition aux biotechnologies marque en effet une forme de résistance au processus hyper-moderne de marchandisation généralisée et de technification radicale de l'espace socio-environnementale. Si cette résistance est essentiellement critique, elle fait néanmoins émerger des formes encore en gestation de modernités alternatives.
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Fouilhé, Martine. "Etude des possibilités de transformation de substrats amylacés par "Schwanniomyces castellii" syn "occidentalis Klocker"." Montpellier 2, 1992. http://www.theses.fr/1992MON20196.
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Schwanniomyces castellii est une levure amylolytique excretant une alpha-amylase et une amyloglucosidase dont les actions sont complementaires pour l'hydrolyse de l'amidon. L'attaque par des extraits amylasiques a ete testee sur des substrats amylacees ayant subi differents traitements thermiques et mecaniques. Les substrats sont des bles et des fractions amylacees de ble, sons, remoulage de ble; farine de mais, de manioc; amidons de manioc, de mais. Pour etre hydrolyses par le systeme amylasique de schwanniomyces castellii (etudes in vitro), ou pour etre metabolises par la souche (culture), les substrats doivent subir un empesage ou un autoclavage. Une culture en fermenteur d'un mutant de schwanniomyces castellii hyperproducteur en amylases et dereprime vis-a-vis du glucose (mutant no 17) a ete realisee en batch avec les sons et remoulage de ble a 100 g. L##1. En culture continue sur farine de manioc, (a ph 3,5; taux de dilution 0,35 h##1; concentration en substrat 40 g. L##1), la productivite en levure a ete de 7 g. L##1. La production d'ethanol par les souches mutantes a5 et no 32 de schwanniomyces castellii a ete comparee a celles obtenue avec la souche sauvage
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Nimbona, Côme. "Effet du système thiorédoxine NADP dépendant sur les protéines des céréales non panifiables (mai͏̈s, sorgho et riz). Conséquences technologiques et mise au point d'un procédé de pastification." Montpellier 2, 1994. http://www.theses.fr/1994MON20148.
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Grace a des techniques recentes permettant la determination de l'etat redox des proteines par marquage des -sh libres et de ceux liberes apres reduction, nous avons montre pour la premiere fois que, dans le grain mature et dans la farine, les proteines des cereales sans gluten se trouvent a l'etat reduit (-sh), alors que celles du ble sont principalement sous un etat oxyde. A partir de donnees actuelles sur le role du systeme thioredoxine nadp dependant (nts) sur les proteines de reserve de ble, nous avons montre que dans le cas des cereales sans gluten, la thioredoxine permet de maintenir a l'etat reduit, ou de reactiver, les proteines oxydees au cours de l'extraction ou au cours du petrissage, facilitant ainsi les interactions entre elles. Ces interactions semblent necessaires pour permettre la formation du reseau proteique, indispensable en panification et en pastification. En panification, a partir de varietes de tres mauvaise qualite boulangere et en utilisant le nts, nous avons pu augmenter le volume du pain jusqu'a 79%. Ainsi, en pastification, grace au nts et a des modifications des conditions habituelles de petrissage suivi de laminage, nous avons fabrique des produits de type pates alimentaires a partir de cereales non panifiables. L'ensemble de ces etudes a abouti a la mise au point d'un nouveau procede de fabrication de produits de type pates alimentaires. Nous sommes parvenus a obtenir des produits ayant une qualite culinaire (gonflement, delitescence, pertes a la cuisson, aspect, etc) comparable a celle des pates de ble dur.
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Duquesnoy, Isabelle. "Etude agrophysiologique, biochimique, protéomique de l'impact de l'arsenic inorganique pentoxyde et trioxyde chez 4 espèces végétales : 2 espèces annuelles (Lycopersicum esculentum et Zea mays) et deux espèces pérennes (Agrostis tenuis et Dechampsia cespitosa)." Clermont-Ferrand 2, 2009. http://www.theses.fr/2009CLF21976.
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L'arsenic est un métalloïde naturellement présent dans l'environnement, majoritairement sous formes inorganiques (arsenate (As(V) et arsenite (As(III) qui se trouvent être les plus toxiques pour les organismes vivants posant ainsi un réel problème de santé publique. Différentes méthodes de bio-réhabilitation des sols contaminés sont en cours de développement. Toutefois, la phytoremédiation, réhabilitation par les plantes, est complexe et les mécanismes de tolérance mis en place par les végétaux à la base du procédé ne sont pas vraiment élucidés. Ce travail a pour pour objectif de contribuer à la compréhension des mécanismes de toxicité et de tolérance chez différentes espèces dites sensibles et tolérantes. L'analyse d'un ensemble de paramètres physiologiques, biochimiques et protéomiques a été conduite chez 2 espèces annuelles cultivées (L. Esculentum et Z. Mays) et 2 espèces pérennes endémiques (A. Tenuis et D. Cespitosa) à travers différentes conditions de milieux hydroponiques arséniés (associant forme d'As (As(V) et As(III)), concentrations (134 et 668 µM) et pH (4-7 et 9). Une inhibition de paramètres de croissance (RRL, RFB, RDB) a été observée chez les quatre espèces, dépendantes des conditions de concentration et de forme d'As voire de valeur de pH du milieu. Toutefois, il est ressorti des résultats physiologiques de L. Esculentum un comportement de tolérance cararctérisé par une croissance maintenue et la stimulation du système enzymatique antioxydant. Ainsi, L. Esculentum montre une tolérance au stade de germination à la forme As(V) à pH9, non observée pour les autres espèces. D. Cespitosa, connue pour être une espèce tolérante hyperaccumulatrice de l'élément arsenic a montré un seuil de tolérance à cet élément fonction de la concentration. Les activités enzymatiques antioxydantes ne sont pas apparues systématiquement stimulées dans leur ensemble. Il ressort que la tolérance, dans la majorité des cas, ne concernerait qu'un pool d'enzymes, et non la totalité et serait variable selon les conditions de milieu, les espèces et organes. Il est intéressant aussi de souligner que l'espèce pérenne A. Tenuis (espèce pseudométallophyte accumulatrice) montre une utilisation limitée de ce type de mécanismes de défense bien que tolérante à une majorité des milieux arseniés étudiés, alors que D. Cespitosa fait largement appel à ce système enzymatique antioxydant avec un niveau de tolérance plus limité. Le protéome foliaire de A. Tenuis montre suite à l'exposition arseniée une fragmentation de protéines fonctionnelles (Oxygen-Evolving Enhancer protein, RuBisCO LSU et SSU, RuBisCo activase et ATP synthase) impliquées dans les processus respiratoires et photosynthétiques particulièrement la RuBisCO, illustrant une réorganisation métabolique de la plante. L'identification d'autres protéines foliaires suggère la probable implication de ces dernières dans les mécanismes de tolérance d'A. Tenuis à l'arsenic
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Shanadi, Govind. "Hollywood representations of biotechnology /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1421624771&sid=3&Fmt=2&clientId=11238&RQT=309&VName=PQD.
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Jahn, Michael. "Characterization of population heterogeneity in a model biotechnological process using Pseudomonas putida." Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-178424.
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Biotechnological processes are distinguished from classical chemistry by employing bio-molecules or whole cells as the catalytic element, providing unique reaction mechanisms with unsurpassed specificity. Whole cells are the most versatile \'factories\' for natural or non-natural products, however, the conversion of e.g. hydrophobic substrates can quickly become cytotoxic. One host organism with the potential to handle such conditions is the gram-negative bacterium Pseudomonas putida, which distinguishes itself by solvent tolerance, metabolic flexibility, and genetic amenability. However, whole cell bioconversions are highly complex processes. A typical bottleneck compared to classical chemistry is lower yield and reproducibility owing to cell-to-cell variability. The intention of this work was therefore to characterize a model producer strain of P. putida KT2440 on the single cell level to identify non-productive or impaired subpopulations.
Flow cytometry was used in this work to discriminate subpopulations regarding DNA content or productivity, and further mass spectrometry or digital PCR was employed to reveal differences in protein composition or plasmid copy number.
Remarkably, productivity of the population was generally bimodally distributed comprising low and highly producing cells. When these two subpopulations were analyzed by mass spectrometry, only few metabolic changes but fundamental differences in stress related proteins were found. As the source for heterogeneity remained elusive, it was hypothesized that cell cycle state may be related to production capacity of the cells. However, subpopulations of one, two, or higher fold DNA content were virtually identical providing no clear hints for regulatory differences. On the quest for heterogeneity the loss of genetic information came into focus. A new work flow using digital PCR was created to determine the absolute number of DNA copies per cell and, finally, lack of expression could be attributed to loss of plasmid in non-producing cells. The average plasmid copy number was shown to be much lower than expected (1 instead of 10-20). In conclusion, this work established techniques for the quantification of proteins and DNA in sorted subpopulations, and by these means provided a highly detailed picture of heterogeneity in a microbial population.
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Mesihää, M. (Markus). "Mass spectrometric characterization of urinary fibrinogen-derived peptides in prostate cancer and renal cell carcinoma." Master's thesis, University of Oulu, 2015. http://urn.fi/URN:NBN:fi:oulu-201512082282.
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In previous studies we have found that urinary fibrinogen-derived peptides are potential tumor markers for renal cell carcinoma. These peptides occur at low concentrations in urine.
Identification of a low-abundant tumor marker requires optimal sample preparation and a highly sensitive analyzer. In this work different chromatographic and mass spectrometric methods were compared and evaluated for tumor marker discovery. We used urine samples from patients with renal cell carcinoma and prostate cancer.
Our main targets were peptides derived from fibrinogen beta with unknown sequence that are produced by differential proteolysis. With our optimized workflow we discovered 26 fibrinogen beta derived peptides that have not been identified in urine previously.
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Dlugosch, Elisabeth [Verfasser], Hermann [Gutachter] Lübbert, and Stefan [Gutachter] Herlitze. "Die Rolle der duralen Mastzellen im Maus Migräne-Modell / Elisabeth Dlugosch ; Gutachter: Hermann Lübbert, Stefan Herlitze ; Fakultät für Biologie und Biotechnologie." Bochum : Ruhr-Universität Bochum, 2018. http://d-nb.info/1154307832/34.
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Trienes, Marco [Verfasser]. "Innovation und Governance über Grenzen? : Perspektiven eines grenzüberschreitenden Regionalen Innovationssystems ; das Beispiel der roten Biotechnologie in der Euregio Maas-Rhein / Marco Trienes." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2014. http://d-nb.info/1058851551/34.
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Pinkerton, Terrence Scott. "The recombinant expression and potential applications of bacterial organophosphate hydrolase in Zea mays L." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/2194.
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Organophosphate hydrolase (OPH, EC 3.1.8.1) is a bacterial enzyme with a broad spectrum of potential substrates that include organophosphorus pesticides, herbicides, and chemical warfare agents. OPH has been expressed successfully in bacterial, fungal, and insect cell culture systems; however, none of these systems produces amounts of enzyme suitable for applications outside of the research laboratory. Therefore, a transgenic Zea mays L. (maize) system was developed to express OPH as an alternate to the current OPH expression systems. The bacterial gene encoding the OPH protein was optimized for transcriptional and translational expression in maize. The optimized gene was inserted into the maize genome under the control of embryo specific, endosperm specific, and constitutive plant promoters. Select transformants were analyzed for the expression of OPH. Expression was observed in the seeds of plants transformed with each of the three constructs with the highest expression observed with the embryo specific and constitutive promoter constructs. The highest OPH expressing lines of transgenic maize had expression levels higher than those reported for the E. coli expression system. OPH was purified from transgenic maize seed and analyzed for posttranslational modification and kinetic properties. OPH was observed to undergo a glycosylation event when expressed in maize that yielded at least two forms of OPH homogolous dimer. The glycosylated form of OPH bound tightly to the Concanavalin A sepharose and remained active after months of storage at room temperature. OPH activity was checked against a number of organophosphate herbicides. Enzymatic activity was observed against the herbicide Amiprophos-methyl and kinetic properties were measured. Enzymatic activity was also tested against the organophosphate Haloxon. Transgenic maize callus, leaf, and seed tissue could be screened for the presence of the optimized opd gene by enzymatic activity. Comparison of the growth of transgenic and control callus on media containing organophosphates showed that the transgenic callus was resistant to the herbicidal effects of haloxon. Transgenic plants expressing OPH were also resistant to the herbicide bensulide when compared to control plants. This indicates that OPH can be used as a screenable marker in plant systems and may be a potential scorable marker system as well.
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Aheto, Denis Worlanyo. "Implication analysis for biotechnology regulation and management in Africa baseline studies for assessment of potential effects of genetically modified maize (Zea mays L.) cultivation in Ghanaian agriculture." Frankfurt, M. Berlin Bern Bruxelles New York, NY Oxford Wien Lang, 2008. http://d-nb.info/99509473X/04.
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Liu, Xiaohua. "Anion-Peptide Adduct Formation and Decomposition As Studied by Fourier Transform Ion Cyclotron Resonance (FT-ICR) Mass Spectrometry." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1748.
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A new “best match” match model has been developed to account for adduct formation on multiply charged peptides observed in negative ion electrospray mass spectrometry. To obtain a stable adduct, the model necessitates an approximate matching of apparent gas-phase basicity (GBapp) of a given proton bearing site on the peptide with the gas-phase basicity (GB) of the anion attaching at that site. Evidence supporting the model is derived from the fact that singly charged adducts were only observed for lower GB anions: HSO4-, I-, CF3COO-. Ions that have medium GBs (NO3-, Br-, H2PO4-) only form adducts having -2 charge states, whereas Cl- (higher GB) can form adducts having -3 charge states.
Hydrogen bonds are the main interactions pertinent to the “Best Match” model, however, ion-ion interactions formed between peptides ([Glu]Fibrinopeptide B, Angiotensin I or [Asn1,Val5]-Angiotensin II) and low GB anions (ClO4- or HSO4-) have been established by CID-MS/MS. Evidence for ion-ion interactions comes especially from product ions formed during the first dissociation step, where, in addition to the expected loss of the anion or neutral acid, other product ions that require covalent bond cleavage (i.e., H2O or NH3 loss) are also observed.
In this study, the “Best Match” model is further supported by the decomposition behavior of adducts formed when Na+/H+ exchange has occurred on peptides. Na+/H+ exchanges were found to occur preferentially at higher acidity sites. Without any Na+/H+ exchange, F- and CH3COO- can hardly form observable adducts with [Glu]Fibrinopeptide B. However, after multiple Na+/H+ exchanges, F- and CH3COO- do form stable adducts. This phenomenon can be rationalized by considering that Na+ cations serve to “block” the highly acidic sites, thereby forcing them to remain overall neutral. This leaves the less acidic protons available to match with higher GB anions.
According to the "best match" model, high GB anions will match with high GBapp sites on the peptide, whereas low GB anions will match with low GBapp peptide sites. High charge states readily augment GBapp of the peptide (through-space effect). Na+/H+ exchanges substantially decrease GBapp by neutralizing charged sites, while slightly increasing intrinsic GBs by the inductive effect.
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Fly, Richard Derek. "Approaches for the study of leaf carbohydrate metabolic compartmentation in arabidopsis thaliana." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5332.
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Thesis (MSc (Plant Biotechnology))--University of Stellenbosch, 2010.Includes bibliography.
ENGLISH ABSTRACT: The study of plants on a sub-cellular level is an important, yet challenging area and its application allows for novel insight into the understanding of metabolism and its regulation. In this study I describe the development of a reverse phase liquid chromatography mass spectrometry (RPLC-MS) technique in which 29 phosphorylated and nucleotide sugars could be detected and quantified. The method was validated with the use of authentic standards and the system displayed very good linearity (Rª > 0.95), while the recovery of the standards added to the plant material before extraction was between 65 and 125%. Further, Arabidopsis thaliana wild type (Col-0) and adenylate kinase (adk1) mutant leaf discs were fed 13C labeled glucose over a period of 24 hours and harvested at defined time intervals. Non aqueous fractionation, and metabolite profiling via the above mentioned rpLC-MS method in conjunction with gas chromatography mass spectrometry (GC-MS) allowed for the detection and quantification of primary metabolites on a sub-cellular level as well as the determination of their relative isotopic label enrichments through primary carbon metabolism. Finally, a yeast complementation system was designed for the identification of tonoplast bound sucrose import proteins. The screening system identified 22 unique sequences from an Arabidopsis thaliana cDNA library. Four unknown sequences were identified, one of which displayed tonoplast membrane association upon in silico analysis. Three ATP-binding proteins were also identified as well as a sub-unit from the exocyst gene family. Further studies will include the functional characterization of the latter, as well as the development of additional cDNA libraries more suited for screening of sequences that encode sucrose importer proteins.
AFRIKAANSE OPSOMMING: Die studie van plante op a sub-sellulere vlak is ‘n belangrike maar uitdagende navorsingsarea en die toepassing daarvan dra by tot unieke insig tot ‘n beter begrip van metabolise regulasie. In die studie bespreek ek die ontwikkeling van ‘n teenoorgestelde fase vloeistof kromatografie massa spektrometrie (RPLC-MS) tegniek waarin 29 gefosforileerde en nukleotied suikers gevind en gekwantifiseer kon word. Geldigverklaring van die metode is bewerkstelling met die gebruik van oorspronklike standaarde and die systeem het baie goeie liniariteit (Rª > 0.95) getoon, terwyl die herstelbaarheid van standaarde wat bygevoeg is by die plant material voor ekstraksie tussen 65% en 125% was. Arabidopsis thaliana wilde type (Col-O) en die adenaliet kinase (adk1) mutant blaar dele is met 13C gemerkte glukose gevoed oor ‘n tydperk van 24 uur en geoes by spesifieke tydstippe. Nie-vloeibare fraksionering en metaboliet uitleg is vermag vanaf die genoemde RPLC-MS metode met behulp van gas kromotografie massa spektrometrie (GC-MS) wat die bepaling en kwantifikasie van primere metaboliete op n sub-sellulere vlak sowel as die bepaling van hul relatiewe isotropiese merker verrykers deur primere metabolisme toelaat. Verder is n gis komplementere systeem ontwerp vir die identifikasie van tonoplas gebinde sukrose invoer proteine. Die verkenningsysteem het 22 unieke volgordes opgelewer vanaf ‘n Arabidopsis thaliana kDNA biblioteek. Vier onbekende volgordes is geidentifiseer, een wat tonoplas membraan assosiasie toon met in silico analise. Drie ATP-bindings proteine is ook geidentifiseer asook ‘n sub-eenheid van die eksosyst geen familie. Verdere studies sal die funksionele karakterisering van die laaste protein insluit, asook die ontwikkeling van additionele kDNA biblioteke meer gepas vir verkenning sodiende identifiseer van volgordes wat sukrose invoer proteine vertaal.
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Chaubet, Nicole. "Structure, organisation et expression des genes d'histones h3 et h4 chez le mais." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13056.
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Trois genes codant pour l'histone h3 et trois genes codant pour l'histone h4 ont ete isoles dans une banque genomique de mais a l'aide de sondes d'oursin, et leurs sequences nucleotidiques ont ete etablies. Ces genes ne renferment pas d'introns et presentent une utilisation des codons tres biaisee en faveur des bases c et g. Un octanucleotide conserve dans les six genes etudies ainsi que dans les qutres genes d'histones de plantes sequences, a ete mis en evidence 200 a 250 nucleotides en amont de l'atg. Les arn messagers transcrits possedent de longues extremites non traduites en 3' et sont polyadenyles. Les genes h3 et h4 existent en 30 a 40 et 50 a 60 copies respectivement par genome haploide. Ces deux familles multigeniques sont organisees en "sous famille
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Hagman, Charlotte. "Method Development in Quantitative and Structural Proteomics using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry." Doctoral thesis, Uppsala University, Department of Engineering Sciences, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4761.
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In this thesis, methods for studying different aspects of proteomics were developed with Fourier Transform Ion Cyclotron Resonance, (FTICR), mass spectrometry. The FTICR technique provides ultra-high mass resolving power, mass accuracy at sub ppm level and sensitivity in the attomole region.
Methods for quantifying biomarkers in body fluids such as cerebrospinal fluid, (CSF), and plasma were developed. Two sets of global markers with different properties were used for quantitative analysis; S-Methyl Thioacetimidate, (SMTA), and S-Methyl Thiopropionimidate, (SMTP), and [H4]- and [D4]-1-Nicotinoyloxy succinimide ester. Reduced ion suppression and higher sensitivity was obtained by coupling a High Performance Liquid Chromatography, (HPLC), system to the FTICR mass spectrometer.
In body fluids, proteins and peptides are present in a broad dynamic concentration range. Therefore, depleting abundant proteins prior to analysis results in decreased ion suppression and increased sensitivity. Two commercial depletion kits were evaluated with the SMTA- and SMTP-markers.
For both types of global markers, the experimental error for quantitative analysis of abundant proteins was less than 30%. This provides a lower limit for the protein up- and down regulations in complex solutions that can be monitored with HPLC-FTICR mass spectrometry.
Together with the identity and quantity of selected proteins the structure, dynamics and interactions with other molecules are of great importance. The later can be elucidated with Hydrogen/Deuterium Exchange, (HDX), mass spectrometry. Structural information at high resolution can be obtained with Collision-Induced Dissociation, (CID), HDX mass spectrometry. In this thesis, exchange rates of amide hydrogens in peptides were in excellent agreement with NMR results.
In some cases, the CID-fragments have different gas-phase exchange properties and as a consequence the solution phase exchange process can not be monitored. By applying Electron Capture Dissociation, (ECD), at ultra-high vacuum, the exchange process at a specific residue could be monitored.
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Patil, Ujwal S. "Magnetic nanoparticles containing labeling reagents for cell surface mapping." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2049.
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Cell surface proteins play an important role in understanding cell-cell communication, cell signaling pathways, cell division and molecular pathogenesis in various diseases. Commonly used biotinylation regents for cell surface mapping have shown some potential drawbacks such as crossing the cell membrane, difficult recovery of biotinylated proteins from streptavidin/avidin beads, interference from endogenous biotin and nonspecific nature of streptavidin. With aim to solve these problems, we introduced sulfo-N-hydroxysuccinimidyl (NHS) ester functionalized magnetic nanoparticles containing cleavable groups to label solvent exposed primary amine groups of proteins. Silica coated iron oxide magnetic nanoparticles (Fe3O4@SiO2 MNPs) were linked to NHS ester groups via a cleavable disulfide bond. Additionally, the superparamagnetic properties of Fe3O4@SiO2 MNPs facilitate efficient separation of the labeled peptides and removal of the detergent without any extra step of purification. In the last step, the disulfide bond between the labeled peptides and MNPs was cleaved to release the labeled peptides. The disulfide linked NHS ester modified Fe3O4@SiO2 MNPs were tested using a small peptide, and a model protein (bovine serum albumin) followed by liquid chromatography-tandem mass spectrometry analysis (LC-MS/MS) of labeled peptides. In the next step, disulfide linked, NHS ester modified Fe3O4@SiO2 MNPs (150 nm) successfully labeled the solvent exposed cell surface peptides of Saccharomyces cerevisae. Electron microscopic analysis confirmed the cell surface binding of NHS ester modified Fe3O4@SiO2 MNPs. Mass spectrometric analysis revealed the presence of 30 unique proteins containing 56 peptides.
Another MNPs based labeling reagent was developed to target solvent exposed carboxyl acid residues of peptides and proteins. The surface of Fe3O4@SiO2 MNPs was modified with free amine groups via a disulfide bond. Solvent exposed carboxyl groups of ACTH 4-11 and BSA were labeled by using1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) chemistry. Upon cleaving the disulfide bond, labeled peptides were analyzed by LC-MS/MS.
The MNPs containing labeling reagents offers specific labeling under physiological conditions and rapid magnetic separation of labeled peptides prior to mass spectrometric analysis. The ability of large Fe3O4@SiO2 MNPs to specifically attach to cell surface makes them a potential candidate to study the surface of variety of different cell types and complex proteins surrounded by lipid bilayer.
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Vieira, Flávia Soares. "Desenvolvimento de métodos baseados em espectrometria de massas e cromatografia líquida para análise de compostos químicos produzidos por bioconversão de glicerina." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8883.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Biodiesel production has been increasing every year, which has generated surpluses of glycerin, the main co-product of the transesterification reaction. In the search for applications to this surplus, microbial fermentation has been highlighted as an alternative to add value to this co- product. In this process, microorganisms are used to convert this abundant carbon source into compounds of high economic value, including organic acids and polyols. However, there are still some technological challenges, such as low yield during the fermentation processes and high dependence of new analytical methods, more sensitive and selective, able to identify and quantify the compounds produced. The objective of this work was to establish new analytical methodologies to identify and quantify compounds from bioconversion processes involving the production of organic acids and polyols. To guarantee the quantification of the target compounds, methods based on ultra-high- performance liquid chromatography (UHPLC) were developed and the photodiode array (PDA) and mass spectrometry (MS) detectors were evaluated as alternatives for the monitoring of these two classes of chemical compounds. The analytes investigated in this study were short chain organic acids: citric acid, fumaric acid, glyceric acid, kojic acid, lactic acid, muconic acid, oxalic acid, propionic acid, succinic acid, xylonic acid; and polyols with spatial isomers, including polyols with 4 carbons (C4: erythritol and threitol), 5 carbons (C5: arabitol, ribitol, xylitol), and 6 carbons (C6: dulcitol, iditol, mannitol, sorbitol) and 7 carbons (C7: volemitol). The UHPLC-PDA method developed for the analysis of organic acids was validated by parameters of linearity, limit of detection and quantification, precision and accuracy. The analytical curves showed good linearity with determination coefficients (R²) higher than 0.999 for all organic acids. Precision and accuracy were adequate with intra-day and inter-day variation coefficients below 4.06% and recovery ranged from 94.90% to 109.63%. The developed UHPLC- MS methods presented greater sensitivity and selectivity in the detection of organic acids and polyols, being able to monitor these analytes even in low quantity. The analytical methods developed in this work are crucial tools in the selection or screening of promising microorganisms for low added value substrates conversion and important to optimize biotechnological processes for production of these compounds of interest.
A produção de biodiesel tem aumentado a cada ano, o que vem gerando excedentes de glicerina, principal coproduto do processo de transesterificação. A biotecnologia se destaca como alternativa promissora para agregação de valor à glicerina. Em processos de fermentação, os microrganismos são utilizados para converter essa abundante fonte de carbono em compostos de maior interesse econômico, como ácidos orgânicos e polióis. No entanto, ainda há alguns desafios tecnológicos, como o baixo rendimento dos processos e a falta de métodos analíticos sensíveis e seletivos capazes de identificar e quantificar os compostos produzidos. O objetivo deste trabalho foi estabelecer metodologias analíticas para identificar e quantificar compostos obtidos a partir de processos de bioconversão, tais como ácidos orgânicos e polióis. Para garantir a quantificação destas substâncias-alvo, métodos baseados em cromatografia líquida de ultra-alta eficiência (UHPLC) acoplada aos detectores de arranjo de fotodiodos (PDA) e de espectrometria de massas (MS) foram avaliados como alternativas para o monitoramento dessas duas classes de compostos químicos. Os analitos investigados nesse estudo foram ácidos orgânicos de cadeia curta, incluindo: ácido cítrico, ácido fumárico, ácido glicérico, ácido kójico, ácido lático, ácido mucônico, ácido oxálico, ácido propiônico, ácido succínico, ácido xilônico; e polióis, estereoisômeros contendo 4 carbonos (C4: eritritol e treitol), 5 carbonos (C5: arabitol, ribitol, xilitol), 6 carbonos (C6: dulcitol, iditol, manitol, sorbitol) e com 7 carbonos (C7: volemitol). O método UHPLC-PDA desenvolvido para análise de ácidos orgânicos foi validado pelos parâmetros de linearidade, limite de detecção e quantificação, precisão e exatidão. As curvas analíticas mostraram boa linearidade com coeficientes de determinação (R²) maiores que 0,999 para todos os ácidos orgânicos. A precisão e exatidão demonstraram ser adequadas com coeficientes de variação intra-dia e inter-dia inferiores a 4,06%, e a recuperação variou de 94,90% a 109,63%. Os métodos de UHPLC-MS desenvolvidos apresentaram maior sensibilidade e seletividade na detecção de ácidos orgânicos e polióis, sendo capaz de monitorar esses analitos mesmo eles estando em baixa quantidade. Os métodos analíticos desenvolvidos neste trabalho são ferramentas cruciais na seleção ou triagem dos microrganismos promissores para conversão de substratos de baixo valor agregado e importantes para a etapa de otimização dos processos biotecnológicos de produção desses compostos de interesse.
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Mähler, Luis Gustavo. ""Mais um vizinho", a Floresta Nacional : mobilização e controvérsias na gestão ambiental em Mato Castelhano-RS." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/17532.
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Esta dissertação é resultado da pesquisa etnográfica desenvolvida junto a os atores envolvidos na gestão ambiental da Unidade de Conservação da Natureza (UC) chamada Floresta Nacional de Passo Fundo (Mato Castelhano/RS). Este universo compõe-se de cientistas, servidores públicos, agricultores e índios kaingang, em diálogo sobre o uso e a preservação da floresta. Nos encontros do Conselho Gestor da UC são expressas visões de mundo que se refletem em formas diferenciadas de apropriação dos elementos do ambiente próprias de cada grupo. Em um contexto de introdução de lavouras transgênicas nas propriedades próximas à área protegida, o estudo visa a apreender pontos de vista sobre a "natureza" e a "sociedade" e sobre o ambiente de Mato Castelhano entre os participantes do Conselho Gestor da UC, pesquisadores, especialistas da área ambiental e agricultores, abordando ainda a perspectiva de índios kaingang acampados na BR-285. Foram realizadas entrevistas semi-estruturadas com índios e conselheiros e observação participante de suas atividades e reuniões, além da análise de documentos. Evidencia-se que o diálogo em relação aos elementos objetos de manejo e conservação é dificultado pela desconsideração da complexidade da maneira de conceber o ambiente entre os diferentes atores locais.This dissertation results from an ethnographic field work among actors who are involved in a process of public management of an Environmental Protected Area, which is called National Forest of Passo Fundo (Mato Castelhano/RS). This universe is composed of scientists, public servants, farmers and a kaingang indigenous group, dialoging about the use of "nature" and its conservancy. In the gatherings of the Management Council of the National Forest are expressed different perspectives in what concerns the appropriation of the area and its elements, which are related to each one's ways to engage themselves in that environment. In a context of transgenic agriculture in the farms around the protected area, the study focus the apprehension of points of view related to "nature" and "society", as well as the environment of Mato Castelhano, among members of the Council, professional researchers, experts on environment issues, farmers, and includes the perspective of the kaingang indians. In a qualitative approach, were made analysis of documents, semi-directive interviews and participant observation during ordinary meetings and tasks of the councilors, and within the indigenous encampment on the highway BR-285. The research evidences that the dialog about use and conservancy of "natural" elements do not reach to consider the different ways of conceive environment among the local actors.
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Rivera, Vélez Sol Maiam. "Targeted carotenoid metabolite profiling in transgenic cereals and correlations with carotenoid gene expression." Doctoral thesis, Universitat de Lleida, 2012. http://hdl.handle.net/10803/96940.
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El meu treball de recerca va consistir en la millora, desenvolupament i aplicació de tècniques analítiques per a l'anàlisi qualitatiu i quantitatiu de carotenoides en cereals, principalment en blat de moro i arròs. Inicialment vaig treballar en l'optimització del mètode d'extracció d'aquests pigments. Es compararen diferents combinacions de solvents per determinar el millor solvent extractant que permetés alliberar tots els carotenoides de la llavor de blat de moro, malgrat les seves diferents polaritats. Addicionalment, vaig millorar i desenvolupar dos mètodes cromatogràfics per HPLC i UHPLC per realitzar la separació d'aquests pigments. Es compararen diverses fases estacionàries i mòbils amb la finalitat de trobar el millor sistema que permetés la separació de la majoria d'aquests compostos. La identificació dels analits es va realitzar mitjançant l'ús detectors de fotodíodes en sèrie i de masses. Es compararen tècniques d'ionització com ara ESI, APCI i APPI per ionitzar aquests pigments.Mi trabajo de investigación consistió en la mejora, desarrollo y aplicación de técnicas analíticas para el análisis cualitativo y cuantitativo de carotenoides en cereales, principalmente en maíz y arroz. Inicialmente trabajé en la optimización del método de extracción de estos pigmentos. Diferentes combinaciones de solventes fueron comparadas para determinar el mejor solvente de extracción, que permitiera liberar de la semilla de maíz, todos los carotenoides a pesar de sus distintas polaridades. Adicionalmente, mejoré y desarrollé dos métodos cromatográficos por HPLC y UHPLC para conseguir realizar la separación de estos pigmentos. Varias fases estacionarias y móviles fueron comparadas con el fin de encontrar el mejor sistema que permitirá la separación de la mayoría de estos compuestos. La identificación de los analitos se realizó mediante el uso detectores de fotodiodos en serie y de masas. Técnicas de ionización tales como ESI, APCI y APPI fueron comparadas para ionizar los pigmentos.
My research program focused on the development and optimization of qualitative and quantitative analytical methodology for carotenoid determination in cereal crops. Initially, I improved the protocol to extract carotenoids from maize and rice tissues. I compared different combinations of solvents in order to identify the most suitable mixture that allowed me to extract, in spite of its different polarities, all the carotenoids present in the samples. I also improved and developed two chromatographic methods by high performance liquid chromatography (HPLC) and ultra high performance liquid chromatography (UHPLC) to separate these pigments. Various stationary and mobile phases were evaluated in order to obtain the most optimal resolution among the different pigments found in the samples. The identification of these molecules was carried out using photo diode array (PDA) and mass (MS) detectors. I investigated the effect of ionizing carotenoids using electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) techniques.
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Carbonneil, Christine. "Etude de l'hydrolyse controlee de la gelatine par des proteases libres et immobilisees." Toulouse, INSA, 1986. http://www.theses.fr/1986ISAT0040.
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Deux proteases d'origine bacterienne, la subtilisine carlsberg (ec. 3. 4. 21. 14, alcalase novo), et une protease neutre de bacillus subtilis (ec. 3. 4. 24. 4, neutrase novo) sont mises en oeuvre pour la production d'hydrolysats de gelatine utilisables comme solutes de remplissage. Les enzymes sont employees sous forme libre et immobilisee par lien covalent sur des rafles de mais. Apres une etude comparative du comportement cinetique des proteases solubles et insolubles sur la gelatine, des hydrolyses controlees discontinues sont effectuees sur deux gelatines de proprietes physico-chimiques differentes, l'une extraite par voie acide, l'autre par chaulage. Les hydrolysats obtenus sont analyses par filtration sur gel en presence de sds. L'une ou l'autre des deux proteases, libre ou immobilisee, permet, a partir de la gelatine alcaline, d'obtenir un hydrolysat presentant une distribution en masses molaires convenable en moins de 15 minutes. Enfin, l'alcalase immobilisee est utilisee dans un reacteur a lit fixe pour la production continue de gelatine modifiee. Le taux d'hydrolyse recherche est obtenu a l'aide d'une quantite faible de complexe enzyme-support et pour un temps de passage tres court. La production de gelatine modifiee par la mise en oeuvre de l'alcalase immobilisee en reacteur continu semble donc rapide, facile et peu couteuse.
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Pawitwar, Shashank Suryakant. "Biochemical characterization of ArsI: a novel C-As lyase for degradation of environmental organoarsenicals." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3470.
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Organoarsenicals such as methylarsenical methylarsenate (MAs(V)) and aromatic arsenicals including roxarsone (4-hydroxy-3-nitrophenylarsenate or Rox(V)) have been extensively used as an herbicide and growth enhancers in animal husbandry, respectively. They undergo environmental degradation to more toxic inorganic arsenite (As(III)) that contaminates crops and drinking water. We previously identified a bacterial gene (arsI) responsible for aerobic MAs(III) demethylation. The gene product, ArsI, is a Fe(II)-dependent extradiol dioxygenase that cleaves the carbon-arsenic (C-As) bond in MAs(III) and trivalent aromatic arsenicals. The objective of this study was to elucidate the ArsI mechanism. Using isothermal titration calorimetry, we determined the dissociation constants (Kd) and ligand-to-protein stoichiometries (N) of ArsI for Fe(II), MAs(III) and aromatic phenyl arsenite. Using a combination of methods including chemical modification, site-directed mutagenesis, and fluorescent spectroscopy, we demonstrated that amino acid residues predicted to participate in Fe(II)-binding (His5-His62-Glu115) and substrate binding (Cys96-Cys97) are all involved in catalysis. Finally, the products of Rox(III) degradation were identified as As(III) and 4-hydroxy-2-nitrophenol, demonstrating that ArsI is a dioxygenase that incorporates one oxygen atom from dioxygen into the carbon and the other to the arsenic to catalyze the cleavage of the C-As bond. These results augment our understanding of the mechanism of this novel C-As lyase.
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Lindholm, Johan. "Development and Validation of HPLC Methods for Analytical and Preparative Purposes." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, Univ.-bibl. [distributör], 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4442.
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Laporte, Sylvie. "Le double visage des inventions biotechnologiques, une source potentielle de risques majeurs." Phd thesis, Université du Droit et de la Santé - Lille II, 2011. http://tel.archives-ouvertes.fr/tel-00686457.
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Les inventions biotechnologiques ont un double visage, une face bienveillante et une face terrifiante, chacune source potentielle de risques majeurs. Comment les contrôler et les réguler ? La recrudescence des catastrophes majeures (crises sanitaires) liées à l'usage de produits biotechnologiques, d'une part, puis l'échec à l'adoption d'un protocole de vérification à la Convention d'interdiction des armes biologiques suivi de l'émergence de nombreuses publications à risques dans le domaine des biotechnologies, d'autre part, démontrent l'omniprésence et la transversalité de cette problématique. Par leur essence duale, les biotechnologies appellent des solutions globales. La voie d'une gestion cohérente semble s'ouvrir au travers d'un corps de règle prenant tous ces paramètres en considération, les risques majeurs. L'avantage de cette législation, si elle admet une modification préalable de la nomenclature des risques majeurs en y intégrant les risques liés aux conflits, reposera sur sa globalité et sur la responsabilisation de tous. Face à une menace biotechnologique qui est perçue comme dominante dans les années à venir, l'émerge d'un ordre public mondial favorable à un accroissement de la responsabilité des Etats à l'égard de la sécurité humaine serait souhaitable. Le but de toute institution étatique étant de garantir à ses ressortissants leur sécurité et leur sûreté quelles que soient les circonstances, cet ordre public pourrait trouver ses bases au sein des réglementations relatives aux droits de l'homme et au droit de l'environnement ; réglementations déjà émancipées de la distinction entre situations de paix, de crises ou de conflits
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Vunk, Helian. "Nästa generations plasmadiagnostik med immunanriktning och riktad proteomik." Thesis, KTH, Skolan för bioteknologi (BIO), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191536.
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Christen, Pierre. "Faisabilite d'un procede a membrane liquide pour l'extraction continue de l'ethanol produit par fermentation." Paris, ENMP, 1987. http://www.theses.fr/1987ENMP0055.
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Une membrane liquide composee d'un support poreux hydrophobe impregne d'un solvant organique a ete mise au point; l'isotridecanol s'est avere etre biocompatible, impermeable aux sels et au glucose et autorise un flux d'ethanol important (35 g/h. M**(2)). Cette membrane liquide mise en oeuvre avec une phase receptrice aqueuse a permis, par l'extraction de l'ethanol inhibiteur, une detoxification significative d'un mout de fermentation en activite: amelioration de la viabilite des levures et de productivite du fermenteur d'un facteur 2,5. En outre, ce procede d'extraction a permis de mettre en evidence l'activite inhibitrice de metabolites secondaires. Une etape supplementaire de concentration en ligne de l'ethanol extrait peut etre realisee en utilisant le procede a membrane liquide avec une phase receptrice gazeuse et un piege a froid. Enfin, une modelisation mathematique des phenomenes de transfert d'ethanol a travers une membrane liquide a permis de mieux cerner les resistances au transfert et a montre l'importance de parametres lies au support (epaisseur, porosite, tortuosite, des pores) et lies au solvant (coefficient de partage et diffusivite)
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Bastidas, Oyanedel Juan-Rodrigo. "Thermodynamic based modelling of biohydrogen production by anaerobic fermentation." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20016/document.
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Ce travail de thèse a eu pour objectif principal l'étude thermodynamique des changements métaboliques dans l'acidogénèse. L'acidogénèse est un procédé anaérobie à double intérêt qui en traitant des résidus organiques, permet de produire des composés chimiques comme l'hydrogène, l'éthanol et les acides organiques. Par conséquent, l'acidogénèse se place comme un procédé biotechnologique dans le concept de bioraffinerie. En outre, ce processus n'a pas besoin de conditions stériles d'opération et fonctionne sur une large gamme de pH. Ces changements métaboliques sont dépendants des modifications dans les conditions opératoires. Afin d'étudier ces changements métaboliques, des expériences basées sur des modifications du ciel gazeux du réacteur par introduction d'azote et sur des changements du pH, ont été menées. Un des résultats les plus intéressants a été l'augmentation du rendement de production d'hydrogène de 1 à 3,2 molH2/molglucose à pH 4,5 et débit de N2 de 58,4 L/d. Ce rendement est proche de la valeur théorique (4 molH2/molglucose). L'étude thermodynamique a permis d'expliquer les mécanismes métaboliques concernant l'hydrogène, dont la production importante, représentée par le rendement de 3,2 molH2/molglucose, est due à la réaction inverse H2/NAD+, qui est thermodynamiquement faisable à faibles pressions partielles d'hydrogène (par exemple 0,02 bar). En outre, les bas rendements en hydrogène ont été expliqués par l'action consommatrice d'hydrogène par la réaction d'homoacetogénèse. Cependant, le modèle n'a pas été capable d'expliquer les changements métaboliques de l'acétate, du butyrate et de l'éthanol lors de la fermentation acidogénique du glucoseThis thesis deals with thermodynamic based modelling of metabolic shifts during acidogenic fermentation. Acidogenic fermentation is an anaerobic process of double purpose: while treating organic residues, it produces chemical compounds, such as hydrogen, ethanol and organic acids. Therefore, acidogenic fermentation arises as an attractive biotechnology process towards the biorefinery concept. Moreover, this process does not need sterile operating conditions and works under a wide range of pH.Changes of operating conditions produce metabolic shifts, inducing variability on acidogenic product yields. In order to study these metabolic shifts, an experiment design was based on reactor headspace N2-flushing (gas phase) and pH step changes (liquid phase). A major result was the hydrogen yield increase from 1 to 3.2 (molH2/molglucose) at pH 4.5 and N2-flushing of 58.4 L/d. This yield is close to the theoretical acidogenic value (4 molH2/molglucose).The thermodynamic model, based on the assumption that acidogenic fermentation is characterised by limited energy available for biological process, allowed to explain the mechanisms that govern hydrogen metabolic shifts, showing that the synthesis of extra hydrogen, i.e. yield of 3.2 (molH2/molglucose), was due to reverse H2/NAD+ redox reaction, which is thermodynamically feasible at low hydrogen partial pressures (e.g. 0.02 bar). Moreover, low hydrogen yields were explained by the action of homoacetogenesis hydrogen consuming reaction. However, the model was not capable to explain the metabolic shifts of acetate, butyrate and ethanol on acidogenic glucose fermentation
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Nord, Christoffer. "The Colours of Diabetes : advances and novel applications of molecular optical techniques for studies of the pancreas." Doctoral thesis, Umeå universitet, Umeå centrum för molekylär medicin (UCMM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-119845.
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Diabetes is a rapidly increasing health problem. In a global perspective,approximately 415 million people suffered from diabetes in 2015 and this number ispredicted to increase to 640 million by 2040. To tackle this pandemic there is a needfor better analytical tools by which we can increase our understanding of the disease.One discipline that has already provided much needed insight to diabetes etiology isoptical molecular imaging. Using various forms of light it is possible to create animage of the analysed sample that can provide information about molecularmechanistic aspects of the disease and to follow spatial and temporal dynamics. The overall aim of this thesis is to improve and adapt existing andnovel optical imaging approaches for their specific use in diabetes research. Hereby,we have focused on three techniques: (I) Optical projection tomography (OPT),which can be described as the optical equivalent of x-ray computed tomography(CT), and two vibrational microspectroscopic (VMS) techniques, which records theunique vibrational signatures of molecules building up the sample: (II) Fouriertransforminfrared vibrational microspectroscopy (FT-IR) and (III) Ramanvibrational microspectroscopy (Raman). The computational tools and hardware applications presented here generallyimprove OPT data quality, processing speed, sample size and channel capacity.Jointly, these developments enable OPT as a routine tool in diabetes research,facilitating aspects of e.g. pancreatic β-cell generation, proliferation,reprogramming, destruction and preservation to be studied throughout the pancreaticvolume and in large cohorts of experimental animals. Further, a novel application ofmultivariate analysis of VMS data derived from pancreatic tissues is introduced.This approach enables detection of novel biochemical alterations in the pancreasduring diabetes disease progression and can be used to confirm previously reportedbiochemical alterations, but at an earlier stage. Finally, our studies indicate thatRaman imaging is applicable to in vivo studies of grafted islets of Langerhans,allowing for longitudinal studies of pancreatic islet biochemistry.viIn summary, presented here are new and improved methods by which opticalimaging techniques can be utilised to study 3D-spatial, quantitative andmolecular/biochemical alterations of the normal and diseased pancreas.
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Torrijos, Michel. "Evaluation des techniques non conventionnelles d'intensification des transferts d'oxygene en fermentation." Toulouse, INSA, 1987. http://www.theses.fr/1987ISAT0020.
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Etude dans le cas particulier de la production de 2,3-butanediol par enterobacter aerogenes. Amelioration du transfert de l'oxygene realisee grace a l'utilisation d'hydroinjecteurs ou de substances capables de vehiculer l'oxygene (n-paraffines et derives fluores)
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Pons, Agnès. "Analyse de la production de xanthane par xanthomonas campestris nrrl b-1459 en cuve agitee et en colonne a bulles a l'aide d'un modele structure." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF2D201.
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Etude comparative des performances des 2 types de bioreacteurs. Analyse du transfert de l'oxygene dans les reacteurs au cours de la fermentation et etude de son influence sur le rendement et la productivite en xanthane
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Corio-Costet, Marie-France. "Modification par le fenpropimorphe du profil sterolique de plantes et effet sur le metabolisme steroidien d'un insecte phytophage (locusta migratoria)." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13155.
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Nous avons adopte une strategie, consistant en la modification qualitative et quantitative de la composition sterolique de plantes. Pour cefaire, nous avons traite des plantes a l'aide d'inhibiteurs de la biosynthese des sterols, possedant essentiellement deux cibles: la cycloeucalenol-obtusifoliol isomerase et la delta-huit-delta-sept-sterol isomerase. En agissant de la sorte, en bloquant diverses etapes de la biosynthese des phytosterols, nous accumulons de nouveaux sterols, en l'occurence des cyclopropylsterols. La molecule utilisee pour induire de telles modifications, est un fongicide systemique: le fenpropimorphe. Nous avons etudie le comportement de cette molecule en tant qu'inhibiteur chez des cellules animales (fibroblastes de souris) et chez des cellules vegetales (mais et ble)
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Kouloura, Eirini. "Phytochemical investigation of Acronychia species using NMR and LC-MS based dereplication and metabolomics approaches." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05P636/document.
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Les plantes médicinales constituent une source inexhaustible de composés (des produits naturels - PN) utilisé en médecine pour la prévention et le traitement de diverses maladies. L'introduction de nouvelles technologies et méthodes dans le domaine de la chimie des produits naturels a permis le développement de méthodes ‘high throughput’ pour la détermination de la composition chimique des extraits de plantes, l'évaluation de leurs propriétés et l'exploration de leur potentiel en tant que candidats médicaments. Dernièrement, la métabolomique, une approche intégrée incorporant les avantages des technologies d'analyse moderne et la puissance de la bioinformatique s’est révélé un outil efficace dans la biologie des systèmes. En particulier, l'application de la métabolomique pour la découverte de nouveaux composés bioactifs constitue un domaine émergent dans la chimie des produits naturels. Dans ce contexte, le genre Acronychia de la famille des Rutaceae a été choisi sur la base de son usage en médecine traditionnelle pour ses propriétés antimicrobienne, antipyrétique, antispasmodique et anti-inflammatoire. Nombre de méthodes chromatographiques modernes, spectrométriques et spectroscopiques sont utilisées pour l'exploration de leur contenu en métabolites suivant trois axes principaux constituant les trois chapitres de cette thèse. En bref, le premier chapitre décrit l’étude phytochimique d’Acronychia pedunculata, l’identification des métabolites secondaires contenus dans cette espèce et l'évaluation de leurs propriétés biologiques. Le deuxième chapitre vise au développement de méthodes analytiques pour l'identification des dimères d’acétophénones (marqueurs chimiotaxonomiques du genre) et aux stratégies utilisées pour la déréplication de ces différents extraits et la caractérisation chimique des composés par UHPLC-HRMSn. Le troisième chapitre se concentre sur l'application de méthodologies métabolomique (RMN et LC-MS) pour l'analyse comparative (entre les différentes espèces, origines, organes), pour des études chimiotaxonomiques (entre les espèces) et pour la corrélation des composés contenus avec une activité pharmacologiqueMedicinal plants constitute an unfailing source of compounds (natural products – NPs) utilised in medicine for the prevention and treatment of various deceases. The introduction of new technologies and methods in the field of natural products chemistry enabled the development of high throughput methodologies for the chemical composition determination of plant extracts, evaluation of their properties and the exploration of their potentials as drug candidates. Lately, metabolomics, an integrated approach incorporating the advantages of modern analytical technologies and the power of bioinformatics has been proven an efficient tool in systems biology. In particular, the application of metabolomics for the discovery of new bioactive compounds constitutes an emerging field in natural products chemistry. In this context, Acronychia genus of Rutaceae family was selected based on its well-known traditional use as antimicrobial, antipyretic, antispasmodic and anti-inflammatory therapeutic agent. Modern chromatographic, spectrometric and spectroscopic methods were utilised for the exploration of their metabolite content following three basic axes constituting the three chapters of this thesis. Briefly, the first chapter describes the phytochemical investigation of Acronychia pedunculata, the identification of secondary metabolites contained in this species and evaluation of their biological properties. The second chapter refers to the development of analytical methods for the identification of acetophenones (chemotaxonomic markers of the genus) and to the dereplication strategies for the chemical characterisation of extracts by UHPLC-HRMSn. The third chapter focuses on the application of metabolomic methodologies (LC-MS & NMR) for comparative analysis (between different species, origins, organs), chemotaxonomic studies (between species) and compound-activity correlations
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Veilleux, Sophie. "L'internationalisation des entreprises de biotechnologie." Thèse, 2008. http://www.archipel.uqam.ca/1020/1/D1673.pdf.
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La présente étude démontre que l'entrepreneurship international, la gestion internationale et la gestion des entreprises de biotechnologie reposent sur une base multifactorielle en ce qui a trait aux entreprises de biotechnologie en santé humaine dans le domaine thérapeutique. Cette théorie multifactorielle de l'internationalisation s'appuie sur l'analyse de 430 accords technologiques répartis entre Montréal et Boston en tenant compte de trois fonctions, soit, la recherche et développement (R-D), la production et le marketing. Il est important de souligner que le tissu socioéconomique distingue les entreprises de Montréal de celles de Boston et module également les caractéristiques des entreprises et la nature des accords technologiques. La théorie multifactorielle tient compte des quatre mesures de l'internationalisation, soit la vitesse, le rythme, la diversité et l'intensité dûment associés aux trois fonctions et à la nature des accords technologiques. Les résultats de notre recherche mettent en lumière l'importance du tissu socioéconomique. Ainsi, la maturité des régions dans le domaine thérapeutique, les ressources humaines et financières disponibles, la proximité d'infrastructures de production et de multinationales, ainsi que l'homogénéité de la population influencent les caractéristiques des entreprises dont dépend l'élaboration d'accords technologiques à l'étranger. Alors que l'expérience précédente du dirigeant et l'obtention de capital de risque entraînent l'augmentation du nombre de brevets et d'employés, l'âge de l'entreprise affecte l'étape de développement de son produit le plus avancé et sa présence en Bourse. À Montréal, l'internationalisation s'inscrit dans le vécu des entreprises en matière de R-D pour parer à l'homogénéité du milieu socioéconomique, pour rechercher la complémentarité des ressources et des compétences. Ces entreprises utilisent particulièrement les achats de licences et les alliances de R-D à la fois avec des universités et avec de petites entreprises étrangères, principalement américaines. À Boston, le tissu socioéconomique permet aux entreprises de se développer à l'échelle nationale en offrant notamment une indépendance financière qui leur concède le privilège de choisir les accords les plus prometteurs, dont ceux avec de grandes corporations, et ce, au moment opportun. La proximité de multinationales favorise les liens et permet de restreindre leurs accords technologiques étrangers dont le rythme de ceux tout de même établis est plus rapide en raison de ce support. D'ailleurs, ces entreprises s'illustrent davantage sur la scène internationale pour le marketing. En fait. les accords de R-D avec des multinationales semblent se convertir en ventes de licences. Enfin, la documentation et la diflusion des apprentissages sur les procédures de formation des accords technologiques influencent la vitesse, le rythme et la diversité de l'internationalisation. Cependant, plus de dirigeants devraient mettre en place des mesures incitatives pour bénéficier de ces avantages. Bref, l'intégration des théories économiques et comportementales de la gestion internationale ainsi que des observations empiriques en entrepreneurship international dans une théorie multifactorielle permet une compréhension intégrée et globale du processus d'internationalisation des entreprises de biotechnologie thérapeutique. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Entrepreneurship international, Internationalisation, Accords technologiques, Biotechnologie.
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Meselson, M., and Simon M. Whitby. "Biotechnology and the Weapons of Mass Destruction: The Future?" 2002. http://hdl.handle.net/10454/985.
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Rupar, Verica. "Investigating the journalistic field the influence of objectivity as a journalistic norm on the public debate on genetic engineering in New Zealand /." 2007. http://adt.waikato.ac.nz/public/adt-uow20070801.115859/index.html.
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Hou, Singyuk. "Studying Nanoparticle/cell and Nanoparticle/biosurface Interaction with Mass Spectrometry." 2015. https://scholarworks.umass.edu/masters_theses_2/273.
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Nanoparticles (NPs) have been used widely in various fields ranging from biomedical applications to life science due to their highly tunable properties. It is essential to understanding how NPs interact with biological systems of interest, therefore, analytical platforms to efficiently track NPs from cell to animal level are essential. In this thesis, laser desorption ionization mass spectrometry (LDI-MS) and inductively-coupled plasma mass spectrometry (ICP-MS) has been developed and applied to quantify NP/cell and NP/biological surface interactions. These two methods provide fast, label-free and quantitative analysis. New capability of LDI-MS to differentiate cell surface-bound and internalized NPs were established and ICP-MS coupled with a library of surface- functionalized AuNPs were used to probe the affinity between NPs and human hair surface. NPs interacting with biological surfaces and plasma membrane were quantified and the interactions were controlled by the chemical properties of the interface between NP and biological systems.
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Sandadi, Sandeep. "Mass transfer, mixing, Chinese hamster ovary cell growth and antibody production characterization using Rushton turbine and marine impellars." 2009. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051902.
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Choukah, Sarah. "Biohacking and code convergence : a transductive ethnography." Thesis, 2020. http://hdl.handle.net/1866/24629.
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Cette thèse se déploie dans un espace de discours et de pratiques revendicatrices, à l’inter- section des cultures amateures informatiques et biotechniques, euro-américaines contempo- raines. La problématique se dessinant dans ce croisement culturel examine des métaphores et analogies au coeur d’un traffic intense, au milieu de voies de commmunications imposantes, reliant les technologies informatiques et biotechniques comme lieux d’expression médiatique. L’examen retrace les lignes de force, les médiations expressives en ces lieux à travers leurs manifestations en tant que codes —à la fois informatiques et génétiques— et reconnaît les caractères analogiques d’expressivité des codes en tant que processus de convergence.
Émergeant lentement, à partir des années 40 et 50, les visions convergentes des codes ont facilité l’entrée des ordinateurs personnels dans les marchés, ainsi que dans les garages de hackers, alors que des bricoleurs de l’informatique s’en réclamaient comme espace de liberté d’information —et surtout d’innovation. Plus de cinquante ans plus tard, l’analogie entre codes informatiques et génétiques sert de moteur aux revendications de liberté, informant cette fois les nouvelles applications de la biotechnologie de marché, ainsi que l’activité des biohackers, ces bricoleurs de garage en biologie synthétique. Les pratiques du biohacking sont ainsi comprises comme des individuations : des tentatives continues de résoudre des frictions, des tensions travaillant les revendications des cultures amateures informatiques et biotechniques.
Une des manières de moduler ces tensions s’incarne dans un processus connu sous le nom de forking, entrevu ici comme l’expérience d’une bifurcation. Autrement dit, le forking est ici définit comme passage vers un seuil critique, déclinant la technologie et la biologie sur plusieurs modes. Le forking informe —c’est-à-dire permet et contraint— différentes vi- sions collectives de l’ouverture informationnelle. Le forking intervient aussi sur les plans des iii semio-matérialités et pouvoirs d’action investis dans les pratiques biotechniques et informa- tiques. Pris comme processus de co-constitution et de différentiation de l’action collective, les mouvements de bifurcation invitent les trois questions suivantes : 1) Comment le forking catalyse-t-il la solution des tensions participant aux revendications des pratiques du bioha- cking ? 2) Dans ce processus de solution, de quelles manières les revendications changent de phase, bifurquent et se transforment, parfois au point d’altérer radicalement ces pratiques ? 3) Quels nouveaux problèmes émergent de ces solutions ?
L’effort de recherche a trouvé ces questions, ainsi que les plans correspondants d’action sémio-matérielle et collective, incarnées dans trois expériences ethnographiques réparties sur trois ans (2012-2015) : la première dans un laboratoire de biotechnologie communautaire new- yorkais, la seconde dans l’émergence d’un groupe de biotechnologie amateure à Montréal, et la troisième à Cork, en Irlande, au sein du premier accélérateur d’entreprises en biologie synthétique au monde. La logique de l’enquête n’est ni strictement inductive ou déductive, mais transductive. Elle emprunte à la philosophie de la communication et de l’information de Gilbert Simondon et découvre l’épistémologie en tant qu’acte de création opérant en milieux relationnels. L’heuristique transductive offre des rencontres inusitées entre les métaphores et les analogies des codes. Ces rencontres étonnantes ont aménagé l’expérience de la conver- gence des codes sous forme de jeux d’écritures. Elles se sont retrouvées dans la recherche ethnographique en tant que processus transductifs.This dissertation examines creative practices and discourses intersecting computer and biotech cultures. It queries influential metaphors and analogies on both sides of the inter- section, and their positioning of biotech and information technologies as expression media. It follows mediations across their incarnations as codes, both computational and biological, and situates their analogical expressivity and programmability as a process of code conver- gence. Converging visions of technological freedom facilitated the entrance of computers in 1960’s Western hobbyist hacker circles, as well as in consumer markets. Almost fifty years later, the analogy drives claims to freedom of information —and freedom of innovation— from biohacker hobbyist groups to new biotech consumer markets. Such biohacking practices are understood as individuations: as ongoing attempts to resolve frictions, tensions working through claims to freedom and openness animating software and biotech cultures. Tensions get modulated in many ways. One of them, otherwise known as “forking,” refers here to a critical bifurcation allowing for differing iterations of biotechnical and computa- tional configurations. Forking informs —that is, simultaneously affords and constrains— differing collective visions of openness. Forking also operates on the materiality and agency invested in biotechnical and computational practices. Taken as a significant process of co- constitution and differentiation in collective action, bifurcation invites the following three questions: 1) How does forking solve tensions working through claims to biotech freedom? 2) In this solving process, how can claims bifurcate and transform to the point of radically altering biotech practices? 3) what new problems do these solutions call into existence? This research found these questions, and both scales of material action and agency, in- carnated in three extensive ethnographical journeys spanning three years (2012-2015): the first in a Brooklyn-based biotech community laboratory, the second in the early days of a biotech community group in Montreal, and the third in the world’s first synthetic biology startup accelerator in Cork, Ireland. The inquiry’s guiding empirical logic is neither solely deductive or inductive, but transductive. It borrows from Gilbert Simondon’s philosophy of communication and information to experience epistemology as an act of analogical creation involving the radical, irreversible transformation of knower and known. Transductive heuris- tics offer unconvential encounters with practices, metaphors and analogies of code. In the end, transductive methods acknowledge code convergence as a metastable writing games, and ethnographical research itself as a transductive process.
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Mahapatra, Sadhan. "Experiments And Analysis on Wood Gasification in an Open Top Downdraft Gasifier." Thesis, 2016. http://etd.iisc.ernet.in/handle/2005/2685.
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The thesis, through experimental and numerical investigations reports on the work related to packed bed reactors in co-current configuration for biomass gasification. This study has extensively focused on the gasification operating regimes and addressing the issues of presence of tar, an undesirable component for engine application.
Systematically, the influence of fuel properties on the gasification process has been studied using single particle analysis and also in packed bed reactors. Studies related to the effect of fuel properties - size, surface area volume ratio and density on the reactor performance are addressed. The influence of these parameters on the propagation rate which indirectly influences the residence time, tar generation, gas compositions is explicitly elucidated. Most of the reported work in literature primarily focuses on counter-current configurations and analysis on propagation flame front/ignition mass flux and temperature profiles mostly under the combustion regime. In this work, flame propagation front movement, bed movement and effective movement for a co-current packed bed reactor of different reactor capacities and a generalized approach towards establishing ‘effective propagation rate’ has been proposed. The work also reports on the importance of particle size and sharing of air from the top and through nozzles on tar generation in the open top down draft reactor configuration.
Firstly, pyrolysis, an important component of the thermochemical conversion process has been studied using the flaming time for different biomass samples having varying size, shape and density. The elaborate experiments on the single particle study provides an insight into the reasons for high tar generation for wood flakes/coconut shells and also identifies the importance of the fuel particle geometry related to surface area and volume ratio. Effect of density by comparing the flaming rate of wood flakes and coconut shells with the wood sphere for an equivalent diameter is highlighted. It is observed that the tar level in the raw gas is about 80% higher in the case of wood flakes and similar values for coconut shells compared with wood pieces. The analysis suggests that the time for pyrolysis is lower with a higher surface area particle and is subjected to nearly fast pyrolysis process resulting in higher tar fraction with low char yield.
Similarly, time for pyrolysis increases with density as observed from the experimental measurements by using coconut shells and wood flakes and concludes the influence on the performance of packed bed reactors. Studies on co-current reactor under various operating conditions from closed top reactor to open top reburn configuration suggests improved residence time reduces tar generation. This study establishes, increased residence time with staged air flow has a better control on residence time and yields lower tar in the raw gas.
Studies on the influence of air mass flux on the propagation rate, peak temperature, and gas quality, establishes the need to consider bed movement in the case of co-current packed bed reactor. It is also observed that flame front propagation rate initially increases as the air mass flux is increased, reaches a peak and subsequently decreases. With increase in air mass flux, fuel consumption increases and thereby the bed movement. The importance of bed movement and its effect on the propagation front movement has been established. To account for variation in the fuel density, normalized propagation rate or the ignition mass flux is a better way to present the result. The peak flame front propagation rates are 0.089 mm/s for 10 % moist wood at an air mas flux of 0.130 kg/m2-s and while 0.095 mm/s for bone-dry wood at an air mass flux of 0.134 kg/m2-s. These peak propagation rates occur with the air mass flux in the range of 0.130 to 0.134 kg/m2-s. The present results compare well with those available in the literature on the effective propagation rate with the variation of air mass flux, and deviations are linked to fuel properties. The propagation rate correlates with mass flux as ̇ . during the increasing regime of the front movement. The extinction of flame propagation or the front receding has been established both experimentally supported from the model analysis and is found to be at an air mass flux of 0.235 kg/m2-s. The volume fraction of various gaseous species at the reactor exits obtained from the experiment is 14.89±0.28 % CO2, 15.75±0.43 % CO and 11.09±1.99 % H2 respectively with the balance being CH4 and N2.
The model analysis using an in-house program developed for packed bed reactor provide a comprehensive understanding with respect to the performance of packed bed reactor under gasification conditions. The model addresses the dependence on air mass flux on gas composition and propagation rate and is used to validate the experimental results.
Based on the energy balance in the reaction front, the analysis clearly identifies the reasons for stable propagation front and receding front in a co-current reactor. From the experiments and modelling studies, it is evident that turn-down ratio of a downdraft gasification system is scientifically established. Both the experimental and the numerical studies presented in the current work establishes that the physical properties of the fuel have an impact on the performance of the co-current reactor and for the first time, the importance of bed movement on the propagation rate is identified.
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Grove, Francois Michael. "The beneficiation of carbonate rich coal seam water through the cultivation of Arthrospira Maxima (Spirulina)." Diss., 2013. http://hdl.handle.net/10500/14665.
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Coal seams are commonly associated with poor quality water that requires treatment. Water treatment can be very expensive and can severely affect the profitability of mining projects. This study investigated the potential cultivation of Arthrospira maxima (Spirulina) in coal seam water to beneficiate coal seam water in order to effectively offset the water treatment cost. The study was conducted in Northern South Africa and formed part of a larger Coal Seam Water Beneficiation Project (CSWBP).
The study consisted of laboratory based Flask Studies and outdoor High Rate Algal Pond Studies. The Flask Studies that were carried out in the on-site field laboratory, found that the coal seam water could provide a suitable medium for Spirulina cultivation. In addition, it was found that the optimal pH for the selected strain ranged between 9 - 10.5 and that the addition of excess iron, up to 100 times the concentration found in defined growth media such as Schlösser’s, to the culture media could enhance productivity.
The High Rate Algal Pond Studies (HRAP) were carried out over a period of 18 months. The studies showed that the coal seam water at the CSWBP is a valuable resource that can reduce media costs by 50% without affecting productivity. In a study encompassing 334 days it was shown that heating the culture through plate heat exchangers would result in a significant increase in productivity and a heated productivity of 19.86 g/m2/day was recorded. An unheated productivity of 14.11 g/m2/day was recorded.
Therefore, it was found that it would be economically feasible to beneficiate coal seam water found at the CSWBP through the cultivation of Arthrospira maxima (Spirulina).Environmental Sciences
M. Sc. (Environmental Science)
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Li, Pin. "Effects of carbon nanotubes on airway epithelial cells and model lipid bilayers : proteomic and biophysical studies." Thesis, 2014. http://hdl.handle.net/1805/5968.
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Indiana University-Purdue University Indianapolis (IUPUI)Carbon nanomaterials are widely produced and used in industry, medicine and scientific research. To examine the impact of exposure to nanoparticles on human health, the human airway epithelial cell line, Calu-3, was used to evaluate changes in the cellular proteome that could account for alterations in cellular function of airway epithelia after 24 h exposure to 10 μg/mL and 100 ng/mL of two common carbon nanoparticles, singleand multi-wall carbon nanotubes (SWCNT, MWCNT). After exposure to the nanoparticles, label-free quantitative mass spectrometry (LFQMS) was used to study differential protein expression. Ingenuity Pathway Analysis (IPA) was used to conduct a bioinformatics analysis of proteins identified by LFQMS. Interestingly, after exposure to a high concentration (10 μg/mL; 0.4 μg/cm2) of MWCNT or SWCNT, only 8 and 13 proteins, respectively, exhibited changes in abundance. In contrast, the abundance of hundreds of proteins was altered in response to a low concentration (100 ng/mL; 4 ng/cm2) of either CNT. Of the 281 and 282 proteins that were significantly altered in response to MWCNT or SWCNT, respectively, 231 proteins were the same. Bioinformatic analyses found that the proteins common to both kinds of nanotubes are associated with the cellular functions of cell death and survival, cell-to-cell signaling and interaction, cellular assembly and organization, cellular growth and proliferation, infectious disease, molecular transport and protein synthesis. The decrease in expression of the majority proteins suggests a general stress response to protect cells. The STRING database was used to analyze the various functional protein networks. Interestingly, some proteins like cadherin 1 (CDH1), signal transducer and activator of transcription 1 (STAT1), junction plakoglobin (JUP), and apoptosis-associated speck-like protein containing a CARD (PYCARD), appear in several functional categories and tend to be in the center of the networks. This central positioning suggests they may play important roles in multiple cellular functions and activities that are altered in response to carbon nanotube exposure. To examine the effect of nanotubes on the plasma membrane, we investigated the interaction of short purified MWCNT with model lipid membranes using a planar bilayer workstation. Bilayer lipid membranes were synthesized using neutral 1, 2-diphytanoylsn-glycero-3-phosphocholine (DPhPC) in 1 M KCl. The ion channel model protein, Gramicidin A (gA), was incorporated into the bilayers and used to measure the effect of MWCNT on ion transport. The opening and closing of ion channels, amplitude of current, and open probability and lifetime of ion channels were measured and analyzed by Clampfit. The presence of an intermediate concentration of MWCNT (2 μg/ml) could be related to a statistically significant decrease of the open probability and lifetime of gA channels. The proteomic studies revealed changes in response to CNT exposure. An analysis of the changes using multiple databases revealed alterations in pathways, which were consistent with the physiological changes that were observed in cultured cells exposed to very low concentrations of CNT. The physiological changes included the break down of the barrier function and the inhibition of the mucocillary clearance, both of which could increase the risk of CNT’s toxicity to human health. The biophysical studies indicate MWCNTs have an effect on single channel kinetics of Gramicidin A model cation channel. These changes are consistent with the inhibitory effect of nanoparticles on hormone stimulated transepithelial ion flux, but additional experiments will be necessary to substantiate this correlation.