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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Optimizing mixing in the dilution system of a paper machine

Steele, Joseph Ronald 19 January 2010 (has links)
In the flow distribution section of a paper machine, known as the head box, water is injected into the fiber suspension (stock) flow through a tee-mixer for more uniform production. This dilution process has two important requirements that must be fulfilled: (1) sufficient mixing so that the dilution flow spreads across the suspension flow and (2) that the injection flow rate not be so large to significantly alter the local head box flow rate. The objective of this research was to find a combination of velocity ratio and tee mixer geometry that lead to the injection flow being well mixed into the stock flow, but at the same time, the injection should not cause the total flow rate to change by more than 1%. Velocity ratios of 0.25, 0.75, 1.33, 1.5 and 2.25 were examined for four different cases of tee mixer geometries using the CFD software Fluent. Two of the cases had added contractions located near the injection point, while the other two cases had a more standard geometry with no added complexities. The pressure drop across the injection point was also measured. Mixing was qualitatively measured by simulating the injection of a passive tracer into the dilution flow. All of the results indicated that the case where the contraction was located after the injection showed the most promising results with quality mixing and lower flow rates. The cases without added contractions showed poor mixing for lower velocity ratios, and for higher velocity ratios, the flow rates were too large. The cases with contractions showed similar mixing, but the outlet flow rates produced were lower when the contraction was located after the injection instead of before it. A velocity ratio of 0.25-0.75 for the mixers with contractions produced acceptable flow rates and sufficient mixing. The simulations also showed that the static pressure for the contraction cases were nearly identical throughout the majority of the pipe. For both contraction cases the pressure drop across the injection increased with increasing injection flow rate. When the contraction was located before the injection, a pressure drop of 16% was calculated. A pressure drop of 18% to 20% across the injection resulted when the contraction was located after the injection.
32

Biodiversité et maladies infectieuses : impact des activités humaines sur le cycle de transmission des leishmanioses en Guyane / Biodiversity and infectious diseases : impact of human activities on the sylvatic transmission cycle of leishmaniases in French Guiana

Kocher, Arthur 23 June 2017 (has links)
Selon l'hypothèse de l'effet de dilution, les écosystèmes les plus riches en espèces seraient également les moins propices à la circulation des agents infectieux du fait de la présence d'hôtes non compétents constituant des impasses épidémiologiques. Dans cette thèse, nous explorons l'existence de ce phénomène sur le modèle des leishmanioses cutanées zoonotiques en Guyane. Des outils moléculaires basés sur l'utilisation des technologies de séquençage haut-débit ont été développés pour étudier le système épidémiologique. Ces outils ont ensuite été employés pour caractériser le cycle de transmission des leishmanioses dans des sites forestiers sujets à différents niveaux de perturbation d'origine humaine. Nos résultats semblent globalement congruents avec l'hypothèse de l'effet de dilution, et indiquent un risque infectieux plus élevé sur le site le plus perturbé. Toutefois, les différences observées entre les sites ne sont pas significatives et d'avantage de données seraient nécessaires pour tirer des conclusions générales. / The dilution effect hypothesis states that more diverse ecological communities are less prone to pathogen transmission because of the presence of non-competent hosts acting as epidemiological dead-ends. In this work, we investigate the existence of this phenomenon in the case of zoonotic cutaneous leishmaniases in French Guiana. Molecular tools based on high-throughput sequencing technologies have been developed to study the epidemiological system. These tools were employed to explore leishmaniases transmission cycles in forest sites undergoing different levels of human-induced perturbations. Our results seem generally congruent with the dilution effect hypothesis, indicating higher disease risk in the most perturbed site. However, differences observed between sites were not significant, and more data is needed to draw general conclusions.
33

Avaliação in vitro da atividade antibacteriana de extratos de Byrsonima ssp E Alchornea ssp: estudo comparativo entre as técnicas de diluição em tubos e microplacas

Moraes, Helen Pimenta de [UNESP] 28 July 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-07-28Bitstream added on 2014-06-13T20:19:00Z : No. of bitstreams: 1 moraes_hp_me_arafcf.pdf: 1421590 bytes, checksum: 13ffb8dfe23f8d17e358dcedf26cd6c1 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / O Brasil apresenta uma grande diversidade de plantas medicinais, cuja utilização pela população vem aumentando cada vez mais. Byrsonima (Malpighiaceae) e Alchornea (Euphorbiaceae) que são plantas do Bioma-Cerrado do estado de São Paulo apresentam compostos com grande potencial de atividade biológica, sendo entretanto, pouco estudadas. A atividade antimicrobiana é uma etapa de extrema importância na caracterização biológica de produtos naturais com potencial farmacológico. Nossos objetivos foram investigar a atividade antibacteriana de extratos metanólicos e clorofórmicos de Byrsonima spp. e Alchornea spp empregando as técnicas de diluição em tubos e em microplacas com leitura espectrofotométrica e visual utilizando resazurina como revelador. Foram utilizadas as bactérias: Escherechia coli, Staphylococcus aureus, Yersinia enterocolitica e Aeromonas hydrophila. Nos ensaios em microplacas e em tubos foi determinada a concentração inibitória mínima (CIM) dos extratos vegetais testados à concentração de 1000æg/mL a 31,25æg/mL. Objetivou-se também comparar a eficácia das metodologias empregadas. Nosso estudo demonstrou maior atividade antibacteriana dos extratos metanólicos tanto de Byrsonima quanto de Alchornea, ressaltando os dados obtidos com B. crassa (MeOH) e B. basiloba (MeOH) que apresentaram acentuada atividade antibacteriana frente aos diferentes microrganismos testados. As metodologias empregadas foram eficazes para essa finalidade sendo as de diluição em microplacas mais vantajosas, pelo emprego de pequenos volumes principalmente os de extratos vegetais que são obtidos em pequenas quantidades. Dentre os dois métodos de microdiluição, a que empregava leitura espectrofotométrica apresentou-se mais sensível, porém a de leitura visual mostrou-se mais prática na leitura final e na interpretação dos resultados. / Brazil presents a great diversity of medicinal plants, whose use by people increases more and more. Byrsonima (Malpighiaceae) and Alchornea (Euphorbiaceae) are plants of Bioma-Cerrado of the state of São Paulo and present composites with great potential of biological activity, but, however, they are little studied. The antimicrobial activity is a stage of extreme importance in the biological characterization of natural products with pharmacological potential. Our objectives were to investigate the antibacterial activity of methanolic and chlorophormic extracts of Byrsonima spp and Alchornea spp using the techniques of dilution in tubes and in microplates with spectrophotometric and visual readings using resazurin. Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica and Aeromonas hydrophila were tested. In the microplate and tubes assays, the minimum innhibitory concentration (MIC) of plant extracts were tested in concentrations between 1000æg/mL and 31.25æg/mL. It was also compared the effectiveness of the methodologies employed. Our study demonstrated greater antibacterial activity of methanolic extracts of both Byrsonima and Alchornea, standing out the data obtained for B. crassa (MeOH) and B. basiloba (MeOH), which presented accented antibacterial activity against the different tested microrganisms. The methodologies employed were efficient for this purpose and the microplate dilution assay is more advantageous, for the fact it uses smaller volumes, mainly for those vegetal extracts that normally are obtained in small amounts. Amongst the two methods of microdilution, the one that used spectrophotometric reading proved to be more sensitive, however, the visual reading procedure was shown to be more practical in the final reading and interpretation of the results.
34

Avaliação in vitro da atividade antibacteriana de extratos de Byrsonima ssp E Alchornea ssp: estudo comparativo entre as técnicas de diluição em tubos e microplacas /

Moraes, Helen Pimenta de. January 2006 (has links)
Orientador: Taís Maria Bauab / Banca: Sérgio Aparecido Torres / Banca: Daisy Nakamura Sato / Resumo: O Brasil apresenta uma grande diversidade de plantas medicinais, cuja utilização pela população vem aumentando cada vez mais. Byrsonima (Malpighiaceae) e Alchornea (Euphorbiaceae) que são plantas do Bioma-Cerrado do estado de São Paulo apresentam compostos com grande potencial de atividade biológica, sendo entretanto, pouco estudadas. A atividade antimicrobiana é uma etapa de extrema importância na caracterização biológica de produtos naturais com potencial farmacológico. Nossos objetivos foram investigar a atividade antibacteriana de extratos metanólicos e clorofórmicos de Byrsonima spp. e Alchornea spp empregando as técnicas de diluição em tubos e em microplacas com leitura espectrofotométrica e visual utilizando resazurina como revelador. Foram utilizadas as bactérias: Escherechia coli, Staphylococcus aureus, Yersinia enterocolitica e Aeromonas hydrophila. Nos ensaios em microplacas e em tubos foi determinada a concentração inibitória mínima (CIM) dos extratos vegetais testados à concentração de 1000æg/mL a 31,25æg/mL. Objetivou-se também comparar a eficácia das metodologias empregadas. Nosso estudo demonstrou maior atividade antibacteriana dos extratos metanólicos tanto de Byrsonima quanto de Alchornea, ressaltando os dados obtidos com B. crassa (MeOH) e B. basiloba (MeOH) que apresentaram acentuada atividade antibacteriana frente aos diferentes microrganismos testados. As metodologias empregadas foram eficazes para essa finalidade sendo as de diluição em microplacas mais vantajosas, pelo emprego de pequenos volumes principalmente os de extratos vegetais que são obtidos em pequenas quantidades. Dentre os dois métodos de microdiluição, a que empregava leitura espectrofotométrica apresentou-se mais sensível, porém a de leitura visual mostrou-se mais prática na leitura final e na interpretação dos resultados. / Abstract: Brazil presents a great diversity of medicinal plants, whose use by people increases more and more. Byrsonima (Malpighiaceae) and Alchornea (Euphorbiaceae) are plants of Bioma-Cerrado of the state of São Paulo and present composites with great potential of biological activity, but, however, they are little studied. The antimicrobial activity is a stage of extreme importance in the biological characterization of natural products with pharmacological potential. Our objectives were to investigate the antibacterial activity of methanolic and chlorophormic extracts of Byrsonima spp and Alchornea spp using the techniques of dilution in tubes and in microplates with spectrophotometric and visual readings using resazurin. Escherichia coli, Staphylococcus aureus, Yersinia enterocolitica and Aeromonas hydrophila were tested. In the microplate and tubes assays, the minimum innhibitory concentration (MIC) of plant extracts were tested in concentrations between 1000æg/mL and 31.25æg/mL. It was also compared the effectiveness of the methodologies employed. Our study demonstrated greater antibacterial activity of methanolic extracts of both Byrsonima and Alchornea, standing out the data obtained for B. crassa (MeOH) and B. basiloba (MeOH), which presented accented antibacterial activity against the different tested microrganisms. The methodologies employed were efficient for this purpose and the microplate dilution assay is more advantageous, for the fact it uses smaller volumes, mainly for those vegetal extracts that normally are obtained in small amounts. Amongst the two methods of microdilution, the one that used spectrophotometric reading proved to be more sensitive, however, the visual reading procedure was shown to be more practical in the final reading and interpretation of the results. / Mestre
35

La dilution isotopique en spectrométrie de masse MALDI-ToF pour la mesure d’interactions entre récepteurs couplés aux protéines G et ligands peptidiques / Isotopic dilution in MALDI-ToF mass spectrometry for measurement of interaction between G protein coupled receptors and peptidic ligands

Rossato, Maxime 04 November 2016 (has links)
La dilution isotopique, SID pour « Stable Isotope Dilution », est une méthode largement utilisée pour la quantification de peptides et protéines en spectrométrie de masse, généralement associée aux techniques d’ionisation ambiante. Les travaux de cette thèse sont donc consacrés à l’application de la méthodologie de la dilution isotopique (SID) en spectrométrie de masse par désorption/ionisation laser assistée par une matrice (MALDI) pour la mesure d’interaction récepteur/ligand en pharmacologie. En effet, un nombre important de pathologies mettent en jeu des récepteurs membranaires tels que les récepteurs couplés aux protéines G (RCPG) en interaction avec différents ligands, souvent peptidiques. En particulier, le récepteur V1A est impliqué dans l’activité vasoconstrictrice de l’hormone peptidique AVP (Arginine VasoPressine) et la contraction de cellules musculaires ainsi que dans certains comportements sociaux. Ce récepteur a été choisi comme modèle d’étude nécessitant le marquage par voie chimique du ligand Homo-HO-LVA (pour « Hydroxy Linear Vasopressin Antagonist »), sélectionné pour sa forte affinité envers le récepteur V1A afin d’introduire l’entité permettant le dosage en SID/MALDI. Cette méthodologie est mise en œuvre via la génération d’une liaison covalente de la matrice HCCA (4-hydroxy-α-cyanocinnamic acid), couramment utilisée pour l’analyse peptidique pour obtenir le peptide modifié (JMV4854) par acylation en position N-terminale. Le but est alors de tirer profit de l’utilisation conjointe de ce marquage et de la matrice neutre HCCE (4-hydroxy-α-cyanocinnamate de méthyle) pour la détection spécifique et sensible de composés jusqu’à des concentrations picomolaires. L’étape stratégique de quantification par dilution isotopique nécessite un étalonnage et une validation statistique avant de pouvoir passer à l’application pharmacologique. Celle-ci consiste à mesurer l’affinité du JMV4854 pour le récepteur V1A par des expériences thermodynamiques de mesure de constantes de dissociation (Kd) afin de déterminer par la suite des constantes de dissociation de molécules non marquées via des expériences de compétition. Un second modèle de récepteur, le CCKB-R (cholecystokinine B receptor), a ensuite été étudié pour valider la méthodologie de quantification. Devant le regain d’intérêt des laboratoires pharmaceutiques pour les expériences cinétiques de mesure de constantes de dissociation, il serait intéressant d’y appliquer cette méthodologie. Celle-ci présente un potentiel intéressant en tant qu’alternative aux méthodologies actuellement incontournables que sont la radioactivité et la fluorescence. Un second d’axe d’étude a été initié avec un marquage conçu pour diriger la fragmentation de peptides pour des mesures en spectrométrie de masse en tandem par ionisation Electrospray (ESI-MS/MS). Des modifications par introduction en position N-terminale des peptides d’une charge fixe ont été envisagées. Des études préliminaires (synthèse d’ions préformés par incorporation d’une entité pyridinium) ont montré un comportement prometteur en fragmentation ouvrant de nouvelles perspectives de quantification. / The SID methodology, for Stable Isotope Dilution, is a widely applied methodology for peptides and proteins analysis in mass spectrometry, usually associated with atmospheric pressure ionisation techniques. This thesis is consequently devoted to the application of SID methodology in matrix assisted laser desorption/ionisation (MALDI) mass spectrometry to quantify receptor/ligand interaction in pharmacology. Indeed, a great number of pathologies involve membrane receptors like G protein coupled receptors (GPCR) in interaction with several ligands, frequently peptides. Particularly, the V1A receptor, is related to vasoconstriction activity of the peptide hormone AVP (arginine vasopressine) and contraction of muscular cells as well as many social behaviors. This receptor was chosen as model, requiring the chemical labelling of the ligand Homo-HO-LVA (Hydroxy Linear Vasopressin Antagonist), selected for its high affinity towards the V1A receptor in order to introduce the entity on which relies the quantification in SID/MALDI. This methodology is applied through the covalent binding of HCCA (4-hydroxy-α-cyanocinnamic acid) matrix, usually encountered in peptide analysis, to obtain the modified peptide (JMV4854) through N-terminal acylation. The objective is to take advantage of the use of both HCCA tagging and HCCE (4-hydroxy-α-cinnamic methyl ester) matrix for the specific and sensitive detection of compounds down to picomolar concentrations. Importantly, quantification with SID requires a calibration protocol and a statistical validation before pharmacological assays. This consists in the measurement of JMV4854 affinity towards V1A-R through thermodynamic experiments in order to quantify the dissociation constant (Kd) and determine afterwards constants for untagged molecules by competitive binding assays. Furthermore, a second receptor model, CCKB-R (cholecystokinine B receptor), was then studied to validate the quantification methodology. Facing the renewed interest in pharmaceutic industry of kinetic experiments for dissociation constant measurement, it would be interesting to apply this new methodology to drug discovery, representing a relevant alternative to current “gold-standard” methodologies such as radioactivity and fluorescence. A second field of research has been initiated with a covalent labelling designed to enhance peptide fragmentation for electrospray-based (ESI-MS/MS) tandem mass spectrometry measurements. Preliminary studies with the synthesis of pre-formed ions like N-terminal substitution with pyridinium entities gave very promising results opening the way of other quantification strategies.
36

Cosmogenic nuclides as a surface exposure dating tool: improved altitude/latitude scaling factors for production rates

Desilets, Darin Maurice January 2005 (has links)
Applications of in situ cosmogenic nuclides to problems in Quaternary geology require increasingly accurate and precise knowledge of nuclide production rates. Production rates depend on the terrestrial cosmic-ray intensity, which is a function of the elevation and geomagnetic coordinates of a sample site and the geomagnetic field intensity. The main goal of this dissertation is to improve the accuracy of cosmogenic dating by providing better constraints on the spatial variability of production rates.In this dissertation I develop a new scaling model that incorporates the best available cosmic-ray data into a framework that better describes the effects of elevation and geomagnetic shielding on production rates. This model is based on extensive measurements of energetic nucleon fluxes from neutron monitor surveys and on more limited data from low-energy neutron surveys. A major finding of this work is that neutron monitors yield scaling factors different from unshielded proportional counters. To verify that the difference is real I conducted an airborne survey of low-energy neutron fluxes at Hawaii (19.7° N 155.5° W) to compare with a nearby benchmark neutron monitor survey. Our data confirm that the attenuation length is energy dependent and suggest that the scaling factor for energetic nucleons is 10% higher between sea level and 4000 m than for low-energy neutrons at this location. An altitude profile of cosmogenic 36Cl production from lava flows on Mauna Kea, Hawaii, support the use of neutron flux measurements to scale production rates but these data do not have enough precision to confirm or reject the hypothesis of energy-dependent scaling factors.
37

Evaluation of thermodilution catheters using both in-vitro and in-vivo models. / CUHK electronic theses & dissertations collection

January 2011 (has links)
Based on data from my in-vitro investigation in the non-pulsatile flow test rig, my best estimate for the random (inter-reading) error was +/-10.0% (95% c.i.) for single and +/-5.8% for triplicate readings and the systematic (between catheters) error was +/-11.6%. Thus, the overall error was +/-15.3% for a single, and +/-13.0% for triplicate readings. / For the in-vitro model, a test rig through which water circulated at different rates with ports to insert catheters into a flow chamber was assembled. Flow rate was measured by an externally placed transonic flow probe and meter. The meter was calibrated by timed filling of a cylinder. Arrow and Edwards 7Fr thermodilution catheters, connected to a Siemens SC9000 cardiac output monitor, were tested. Thermodilution readings were made by injecting 5 mL of ice-cold water. Measurement error was divided into random and systematic components, which were determined separately. Between-readings (random) variability was determined for each catheter by taking sets of 10 readings at different flow rates. Coefficient of variation (CV) was calculated for each set and averaged. Between-catheters systems (systematic) variability was derived by plotting calibration lines for sets of catheters. Slopes were used to estimate the systematic component. Performances of three cardiac output monitors were compared: Siemens SC9000, Siemens Sirecust 1261, and Philips MP50. After the constant rate model, I also developed a pulsatile model and did a similar evaluation. / For the in-vivo model, ten domestic pigs, weight 27--32kg, were anaesthetized with propofol and ketamine infusion. The aortic flow probe was surgically placed via a left thoracotomy. A pulmonary artery catheter sheath was inserted in the right internal jugular vein. Both Arrow and Edwards catheters were used. A 10 ml, room temperature, saline injectate was used and cardiac output was calculated using the Seimens SC9000 monitor. Sets of cardiac output readings were taken over 5 minute intervals of stable haemodynamics. Catheters were frequently changed and cardiac output increased (e.g. Dopamine and Adrenaline) and decreased (e.g. Trinitrate and Beta-Blocker) using drug infusions. Baseline (e.g. no drug intervention) and drug treatment data were analyzed separately. / For the pulsatile model, the best estimate for the random (inter-reading) error (95% c.i.) was +/-16.7% for single and +/-9.7% for triplicate readings and the systematic (between catheters) error was +/-21.1 %. Thus, the overall error was +/-26.9% for a single, and +/-23.2% for triplicate readings. / I set out to evaluate in the pig model two types of measurement errors, random and systematic errors, which I defined using the test rig in-vitro, the coefficient of variation (CV) was +2.8% (95% c.i.), with random error (95% c.i.) of + 5.5%. But if the ranges of cardiac output was widened, the error was increased to + 19.3% . The systematic component ofthe error (95% c.i.) was +20.0%. / There was a good linear regression relationship between the two methods (e.g. thermodilution and flow probe). The mean correlation coefficient was 0.95 (0.9--0.99, 95% c.i.) based on data from 8 pigs'. However, there were significant systematic errors due to calibration of the measurement systems between pig experiment and catheter testings. By eliminating the systematic errors based on the calibration line corrections, I was able to draw modified Bland and Altman plots for the 8 pigs. The bias was eliminated and become 0 L/min. The limits of agreement or percentage errors of this analysis, were within the +/-30% limits. / Thermodilution cardiac output, measured using a pulmonary artery catheter and cardiac output monitor, is the reference standard against which all new methods of cardiac output measurement are judged. There has been a recent decline in the use of pulmonary artery thermodilution cardiac output in favour of less invasive methods. When validating these new methods comparisons are made using Bland and Altman analysis with single bolus thermodilution as the accepted reference method. 95% confidence intervals and percentage errors are generated that rely on a precision of +/-20% (Stetz et al (1982)) for thermodilution measurements. However, this precision is now being questioned as it is based on data collected over 30-years ago. Lack of precision of this reference standard, and uncertainty about its true values, causes difficulty when validating new cardiac output technology. Thus, the aim of this thesis was to reappraise the error of thermodilution by testing currently available catheters in both in-vitro and in-vivo settings. / When testing in haemodynamically unstable conditions (e.g. high and low flow states), the percentage error was increased by about +/-15% in the treatment groups comparing with baseline group data. This finding was in agreement with the growing world opinion that thermodilution may not be as accurate as originally thought, in extreme haemodynamic conditions, such as hypovolaemia or high cardiac output states. / Yang, Xiaoxing. / Adviser: Lester August Hall Critchley. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 165-178). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
38

Fertilização artificial de ovócitos de curimbatá, Prochilodus lineatus

Souza, Bruno Estevão de [UNESP] 29 November 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-29Bitstream added on 2014-06-13T19:27:37Z : No. of bitstreams: 1 souza_be_me_jabo.pdf: 761249 bytes, checksum: d4605eba9bcf738bd4d794a1e0b76819 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A motilidade espermática é um fator chave para a determinação da qualidade do sêmen e sua capacidade de fertilização. Vários fatores influenciam a motilidade espermática como: espécie estudada, qualidade dos gametas, tipo, volume, temperatura e pH da solução ativadora. Assim sendo, o presente trabalho objetivou avaliar o efeito que a temperatura da solução ativadora e, a relação volume de sêmen:água exercem sob a duração da motilidade espermática. Foram utilizados 12 machos de curimbatá, Prochilodus lineatus com peso e comprimento padrão médio de 405,83 ± 134,20 g, 25,63 ± 3,19cm, respectivamente. Os reprodutores receberam duas doses de extrato de hipófise de carpa (dose inicial de 0,5 mg.kg-1 e final de 5,0 mg.kg-1). Do sêmen dos 12 machos foi realizado um “pool” e, analisada a concentração e o índice de sobrevivência espermática, bem como, a duração da motilidade espermática. Para o primeiro ensaio foi utilizado um delineamento experimental inteiramente casualizado e os tratamentos foram compostos pelos volumes de sêmen provenientes do “pool” e a água nas proporções de: 1:1, 1:2, 1:20, 1:200, 1:2000, 1:20000 e 1:100000SL, respectivamente. O segundo ensaio utilizou um delineamento experimental inteiramente casualizado os tratamentos foram constituídos por alíquotas de 5μL do “pool” de sêmen e, adicionadas a 200μL de solução ativadora nas seguintes temperaturas: 5, 10, 15, 20, 25, 30, 35, 40, 45 e 50°C. A duração da motilidade espermática do curimbatá, P. lineatus teve um comportamento linear ascendente em função do aumento da diluição a partir de 1:2SL sêmen:água (23,04s), até atingir o valor máximo estudado que foi de 1:100.000SL sêmen:água, com a duração da motilidade espermática de 28,83s Os melhores resultados de duração da motilidade espermática em função da temperatura da solução ativadora foram obtidos... / Sperm motility is a key element to qualify semen and its fertilization capacity. Several factors act on sperm motility such as studied species, gametes quality, kind, volume, temperature and pH of activation swimming solution. That way, this study had as a goal evaluate the efect that the temperature of active solution and semen:water volume roll exert on the sperm motility duration. Twelve male curimbatás, Prochilodus lineatus with average weight and medium standard length of 405,83 ± 134,20 g, 25,63 ± 3,19cm, respectively were used. Reproducers got two doses of pituitary extract from carp (initial dose of 0,5 mg.kg-1 and final of 5,0 mg.kg- 1). Whit the semen of those 12 male animals was made a pool and analysed its concentration and spermatic survival index and also sperm motility duration. For the first analysis it was utilized an experimental design entirely randomized and treatments were compound by semen volume deriving from that pool and the water on the proportion of 1:1, 1:2, 1:20, 1:200, 1:2000, 1:20000 e 1:100000SL, respectively. The second analysis utilized an experimental delineation entirely randomized, treatment were composed by 5μL from the pool of the semen and added to a 200μL active solution on the following temperatures: 5, 10, 15, 20, 25, 30, 35, 40, 45 e 50°C. Sperm motility duration of “curimbatá”, P. lineatus had an ascendent linear behavior in function of dilution increasing from 1:2SL semen:water (23,04s), until it gets the maximum studied value that was 1:100.000SL semen:water with the sperm motility duration of 28,83s. Best results of sperm motility duration in function of active solution temperature were gotten in temperature of 20°C wich provided a medium duration of motility of 22,51 ± 0,79 seconds.
39

Continuous degradation of phenol at low levels using Pseudomonas putida immobilised in calcium alginate

Mordocco, Angela Maria, University of Western Sydney, Macarthur, Faculty of Business and Technology January 1996 (has links)
Biodegradation is the breakdown of a compound by a biological organism. Over the past few decades, the biodegradation of compounds such as phenol has been researched extensively. Phenol research has shown that certain organisms are capable of utilising it as an energy source, and a variety of methods are available for its removal. Unfortunately, there is lack of research on phenol degradation at low concentrations. The majority of research performed on phenol degradation has used concentrations above 500 mg, while phenol is highly toxic at levels below 25 mg. The aim of this research was to pursue the problem of phenol degradation at below 100 mg and develop a system able to degrade phenol at such levels. The system consisted of a bioreactor developed to run in continuous mode, using Ps. putida immobilised in calcium alginate. A standard method was modified to quantitatively analyze effluent phenol levels, and a medium designed to increase the longevity of calcium alginate beads in continuous culture. A continuous flow bioreactor was also designed using an overflow weir for use with immobilised cells. Based on the results obtained, immobilisation offers increased stability and increased protection for cells under extreme conditions and is able to use higher dilution rates than cells under continuous culture / Master of Science (Hons)
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Open stope hangingwall design based on general and detailed data collection in unfavourable hangingwall conditions

Capes, Geoffrey William 16 April 2009
This thesis presents new methods to improve open stope hangingwall (HW) design based on knowledge gained from site visits, observations, and data collection at underground mines in Canada, Australia, and Kazakhstan. The data for analysis was collected during 2 months of research at the Hudson Bay Mining and Smelting Ltd. Callinan Mine in Flin Flon, Manitoba, a few trips to the Cameco Rabbit Lake mine in northern Saskatchewan, and 3 years of research and employment at the Xstrata Zinc George Fisher mine near Mount Isa, Queensland, Australia. Other sites visited, where substantial stope stability knowledge was accessed include the Inco Thompson mines in northern Manitoba; BHP Cannington mine, Xstrata Zinc Lead Mine, and Xstrata Copper Enterprise Mine, in Queensland, Australia; and the Kazzinc Maleevskiy Mine in north-eastern Kazakhstan. An improved understanding of stability and design of open stope HWs was developed based on: 1) Three years of data collection from various rock masses and mining geometries to develop new sets of design lines for an existing HW stability assessment method; 2) The consideration of various scales of domains to examine HW rock mass behaviour and development of a new HW stability assessment method; 3) The investigation of the HW failure mechanism using analytical and numerical methods; 4) An examination of the effects of stress, undercutting, faulting, and time on stope HW stability through the presentation of observations and case histories; and 5) Innovative stope design techniques to manage predicted stope HW instability. An observational approach was used for the formulation of the new stope design methodology. To improve mine performance by reducing and/or controlling the HW rock from diluting the ore with non-economic material, the individual stope design methodology included creating vertical HWs, leaving ore skins or chocks where appropriate, and rock mass management. The work contributed to a reduction in annual dilution from 14.4% (2003) to 6.3% (2005), an increase in zinc grade from 7.4% to 8.7%, and increasing production tonnes from 2.1 to 2.6 Mt (Capes et al., 2006).

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