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Emulsions en contact avec la feuille de bananier pour des applications phytosanitaires : impact, étalement et imprégnation
No full textOptimizing phytosanitary spraying on field crops is a major environmental and health issue. It is in this context that, in partnership with Compagnie Fruitière, a leading European banana producer, we are studying the physico-chemical interaction mechanisms of model phytosanitary formulations with banana leaves. These formulations have been developed to combat Black Cercosporiasis of banana, one of the most serious diseases affecting banana production, causing major losses in yield and fruit quality. After contact with a banana leaf, we compare the impact, spreading and impregnating properties of a mineral oil alone, of direct emulsions of this oil currently used by our partner, and of original inverse emulsions of this same oil.First, we characterize the stability and droplet size distribution of the dispersed phase, as well as the rheological properties of the different emulsions.The impact of individual drops of the different formulations on a banana leaf is visualized using a high-speed camera. Analysis of the impact dynamics reveals that, at short times (<10ms), drops of direct emulsion exhibit a splashing phenomenon that generates the emission of secondary droplets from the initial drop after impact on the leaf, then retract; in contrast, reverse emulsions spread out without destabilizing or retracting, in a manner quite similar to pure oil drops. The absence of splashing could be an advantage of reverse emulsions over direct emulsions, both in terms of reducing disease dispersal and the phytosanitary risk of soil pollution.The evolution of the spread of a controlled volume of sprays of these different formulations on the banana leaf is quantified. In all cases, an anisotropic spread was observed, favored in the direction of the leaf's secondary grooves. At long times (t<35min)) all formulations exhibit a slow evolution of the spray coverage rate following a power law ta, α=0.27±0.05 compatible with Tanner's law for the spreading of an individual drop. However, the spreading of direct emulsion droplet sprays is preceded by a latent period (t<2min) when the coverage rate does not evolve.Oil and emulsion impregnation is studied by infrared micro-spectroscopy. Following the deposition of a thick film of oil on the surface, infrared mapping shows that the oil accumulates mainly in the leaf parenchyma. Impregnation dynamics studies suggest Fick diffusion of the oil preceded by an effective diffusion coefficient D = (1.2±0.8) ×10-12 m2/s, preceded by a lag time of around 3.6 hours. Under the same experimental conditions, for inverse emulsions, oil impregnation is observed, but absent in the case of direct emulsion. This result suggests that the oil/sheet interface plays a major role in the impregnation process. Spray impregnation of emulsions is also quantified, confirming a preferred impregnation mechanism for reverse emulsion.L’optimisation des pulvérisations phytosanitaires sur les grandes cultures est un enjeu environnemental et sanitaire majeur. C’est dans ce contexte, qu’en partenariat avec la Compagnie Fruitière, leader européen dans la production de bananes, nous étudions les mécanismes d’interactions physico-chimiques de formulations phytosanitaires modèles avec les feuilles de bananier. Ces formulations sont développées pour lutter contre la Cercosporiose noire du bananier, une des maladies les plus graves pour la production des bananes qui cause des pertes importantes de rendement et de qualité des fruits. Nous comparons après mise en contact avec une feuille de bananier, les propriétés d’impact, d’étalement et d’imprégnation d’une huile minérale seule, d’émulsions directes de cette huile utilisées actuellement par notre partenaire, et d’émulsions inverses originales de cette même huile.Dans un premier temps, nous caractérisons la stabilité la distribution de taille des gouttelettes de la phase dispersée ainsi que les propriétés rhéologiques des différentes émulsions.L’impact de gouttes individuelles des différentes formulations sur une feuille de banane est visualisé par une caméra rapide. L’analyse de la dynamique d’impact révèle qu’aux temps courts (<10ms), les gouttes d’émulsion directe exhibent un phénomène d’éclaboussures qui génère l’émission de gouttelettes secondaires issues de la goutte initiale après impact sur la feuille, puis se rétractent ; au contraire, les émulsions inverses s’étalent sans se déstabiliser et sans rétractation, de manière assez similaire aux gouttes d’huile pure. L’absence d’éclaboussures pourrait constituer un avantage des émulsions inverses par rapport aux émulsions directes, tant en termes de réduction de la dispersion de la maladie que du risque phytosanitaire de pollution des sols. L’évolution de l’étalement d’un volume contrôlé de sprays de ces différentes formulations sur la feuille de banane est quantifiée. On observe, dans tous les cas un étalement anisotrope, privilégié dans la direction des rainures secondaires de la feuille. Aux temps longs (t<35min)) toutes les formulations exhibent une évolution lente du taux de couverture du spray suivant une loi de puissance ta, α=0.27±0.05 compatible avec la loi de Tanner pour l’’étalement d’une goutte individuelle. Cependant l’étalement des sprays de gouttes d’émulsion directe est précédé par une période de latence (t<2min) où le taux de couverture n’évolue pas. L’imprégnation de l'huile et des émulsions est étudiée par micro-spectroscopie infrarouge. À la suite du dépôt d’un film épais d’huile sur la surface, les cartographies infrarouges démontrent que l'huile s'accumule principalement dans les parenchymes palissadiques des feuilles. Les études de dynamique d’imprégnation suggèrent une diffusion de Fick de l’huile précédée avec un coefficient de diffusion effectif D = (1.2±0.8) ×10−12 m2/s, précédé d’une d’un temps de latence de l’ordre de 3.6 heures. Dans les mêmes conditions expérimentales, pour les émulsions inverses, l'imprégnation de l'huile est observée, mais absente dans le cas d'une émulsion directe. Ce résultat suggère le rôle majeur de l’interface huile /feuille dans le processus d’imprégnation. L'imprégnation des émulsions sous forme d'un spray est elle aussi quantifiée et confirme un mécanisme d’imprégnation privilégié pour l’émulsion inverse
Emulsions in contact with banana leaf for phytosanitary applications : impact, spreading and impregnation
No full textL’optimisation des pulvérisations phytosanitaires sur les grandes cultures est un enjeu environnemental et sanitaire majeur. C’est dans ce contexte, qu’en partenariat avec la Compagnie Fruitière, leader européen dans la production de bananes, nous étudions les mécanismes d’interactions physico-chimiques de formulations phytosanitaires modèles avec les feuilles de bananier. Ces formulations sont développées pour lutter contre la Cercosporiose noire du bananier, une des maladies les plus graves pour la production des bananes qui cause des pertes importantes de rendement et de qualité des fruits. Nous comparons après mise en contact avec une feuille de bananier, les propriétés d’impact, d’étalement et d’imprégnation d’une huile minérale seule, d’émulsions directes de cette huile utilisées actuellement par notre partenaire, et d’émulsions inverses originales de cette même huile.Dans un premier temps, nous caractérisons la stabilité la distribution de taille des gouttelettes de la phase dispersée ainsi que les propriétés rhéologiques des différentes émulsions.L’impact de gouttes individuelles des différentes formulations sur une feuille de banane est visualisé par une caméra rapide. L’analyse de la dynamique d’impact révèle qu’aux temps courts (<10ms), les gouttes d’émulsion directe exhibent un phénomène d’éclaboussures qui génère l’émission de gouttelettes secondaires issues de la goutte initiale après impact sur la feuille, puis se rétractent ; au contraire, les émulsions inverses s’étalent sans se déstabiliser et sans rétractation, de manière assez similaire aux gouttes d’huile pure. L’absence d’éclaboussures pourrait constituer un avantage des émulsions inverses par rapport aux émulsions directes, tant en termes de réduction de la dispersion de la maladie que du risque phytosanitaire de pollution des sols. L’évolution de l’étalement d’un volume contrôlé de sprays de ces différentes formulations sur la feuille de banane est quantifiée. On observe, dans tous les cas un étalement anisotrope, privilégié dans la direction des rainures secondaires de la feuille. Aux temps longs (t<35min)) toutes les formulations exhibent une évolution lente du taux de couverture du spray suivant une loi de puissance ta, α=0.27±0.05 compatible avec la loi de Tanner pour l’’étalement d’une goutte individuelle. Cependant l’étalement des sprays de gouttes d’émulsion directe est précédé par une période de latence (t<2min) où le taux de couverture n’évolue pas. L’imprégnation de l'huile et des émulsions est étudiée par micro-spectroscopie infrarouge. À la suite du dépôt d’un film épais d’huile sur la surface, les cartographies infrarouges démontrent que l'huile s'accumule principalement dans les parenchymes palissadiques des feuilles. Les études de dynamique d’imprégnation suggèrent une diffusion de Fick de l’huile précédée avec un coefficient de diffusion effectif D = (1.2±0.8) ×10−12 m2/s, précédé d’une d’un temps de latence de l’ordre de 3.6 heures. Dans les mêmes conditions expérimentales, pour les émulsions inverses, l'imprégnation de l'huile est observée, mais absente dans le cas d'une émulsion directe. Ce résultat suggère le rôle majeur de l’interface huile /feuille dans le processus d’imprégnation. L'imprégnation des émulsions sous forme d'un spray est elle aussi quantifiée et confirme un mécanisme d’imprégnation privilégié pour l’émulsion inverse.Optimizing phytosanitary spraying on field crops is a major environmental and health issue. It is in this context that, in partnership with Compagnie Fruitière, a leading European banana producer, we are studying the physico-chemical interaction mechanisms of model phytosanitary formulations with banana leaves. These formulations have been developed to combat Black Cercosporiasis of banana, one of the most serious diseases affecting banana production, causing major losses in yield and fruit quality. After contact with a banana leaf, we compare the impact, spreading and impregnating properties of a mineral oil alone, of direct emulsions of this oil currently used by our partner, and of original inverse emulsions of this same oil.First, we characterize the stability and droplet size distribution of the dispersed phase, as well as the rheological properties of the different emulsions.The impact of individual drops of the different formulations on a banana leaf is visualized using a high-speed camera. Analysis of the impact dynamics reveals that, at short times (<10ms), drops of direct emulsion exhibit a splashing phenomenon that generates the emission of secondary droplets from the initial drop after impact on the leaf, then retract; in contrast, reverse emulsions spread out without destabilizing or retracting, in a manner quite similar to pure oil drops. The absence of splashing could be an advantage of reverse emulsions over direct emulsions, both in terms of reducing disease dispersal and the phytosanitary risk of soil pollution.The evolution of the spread of a controlled volume of sprays of these different formulations on the banana leaf is quantified. In all cases, an anisotropic spread was observed, favored in the direction of the leaf's secondary grooves. At long times (t<35min)) all formulations exhibit a slow evolution of the spray coverage rate following a power law ta, α=0.27±0.05 compatible with Tanner's law for the spreading of an individual drop. However, the spreading of direct emulsion droplet sprays is preceded by a latent period (t<2min) when the coverage rate does not evolve.Oil and emulsion impregnation is studied by infrared micro-spectroscopy. Following the deposition of a thick film of oil on the surface, infrared mapping shows that the oil accumulates mainly in the leaf parenchyma. Impregnation dynamics studies suggest Fick diffusion of the oil preceded by an effective diffusion coefficient D = (1.2±0.8) ×10-12 m2/s, preceded by a lag time of around 3.6 hours. Under the same experimental conditions, for inverse emulsions, oil impregnation is observed, but absent in the case of direct emulsion. This result suggests that the oil/sheet interface plays a major role in the impregnation process. Spray impregnation of emulsions is also quantified, confirming a preferred impregnation mechanism for reverse emulsion
Faith in Fiordland: An Architectural Prospection on Spirituality and Tourism
No full textIn an increasingly secular society, the spirit has been demoted as an architectural priority. If the presence of religion in the Western world is diminishing, what remains of the capacity for architecture to accommodate spiritual experiences? This thesis aims to speculate on a potential future for the spiritual architectural typology in a society of growing agnosticism and secularism. While this trend is worldwide, this thesis will specifically address the deficit of inspiring architecture which is able to engage the spirit within New Zealand. As a young nation, New Zealand not only lacks the historical architecture brought about by ancient religiosity, it also falls victim to an economic conservatism exercised by a modest building sector which is not investing in the progression of religious architecture seen in nations with established values in the typology. This deficit provides a significant challenge for this thesis to address, the breadth of which is condensed through the specification of Fiordland as the site for such heavy subject matter. The journey from Lake Te Anau towards Milford Sound through the magnificent Fiordland is a spectacular one undertaken by almost one million tourists and nationals each year. It is this path which will accommodate a selection of four sites for the outcome of this research, the designs on which will aim to conjure specific spiritual experiences. These not only fill a void of such a typology within the nation, but also compensate for an observed inadequacy within the existing architecture of Fiordland. Historically, religion has been the most effective galvaniser of the spirit. By interpolating aspects of religious practice and seeking consensus between the religious and nonreligious spiritual condition, this thesis seeks to investigate the existing overlap between what is natural, architectural, touristic and spiritual, proposing an architecture which harmonises these seemingly miscellaneous elements
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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