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1
Chen, Xiaochen. "Tracking vertex flow on 3D dynamic facial models." Diss., Online access via UMI:, 2008.
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Ekström, Sven-Erik. "A vertex-centered discontinuous Galerkin method for flow problems." Licentiate thesis, Uppsala universitet, Avdelningen för beräkningsvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-284321.
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The understanding of flow problems, and finding their solution, has been important for most of human history, from the design of aqueducts to boats and airplanes. The use of physical miniature models and wind tunnels were, and still are, useful tools for design, but with the development of computers, an increasingly large part of the design process is assisted by computational fluid dynamics (CFD). Many industrial CFD codes have their origins in the 1980s and 1990s, when the low order finite volume method (FVM) was prevalent. Discontinuous Galerkin methods (DGM) have, since the turn of the century, been seen as the successor of these methods, since it is potentially of arbitrarily high order. In its lowest order form DGM is equivalent to FVM. However, many existing codes are not compatible with standard DGM and would need a complete rewrite to obtain the advantages of the higher order. This thesis shows how to extend existing vertex-centered and edge-based FVM codes to higher order, using a special kind of DGM discretization, which is different from the standard cell-centered type. Two model problems are examined to show the necessary data structures that need to be constructed, the order of accuracy for the method, and the use of an hp-adaptation scheme to resolve a developing shock. Then the method is further developed to solve the steady Euler equations, within the existing industrial Edge code, using acceleration techniques such as local time stepping and multigrid. With the ever increasing need for more efficient and accurate solvers and algorithms in CFD, the modified DGM presented in this thesis could be used to help and accelerate the adoption of high order methods in industry.
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Guarino, Giuseppe. "Vehicular Traffic on Networks: Comparison among Solutions Modeling Vertex Flow". Doctoral thesis, Universita degli studi di Salerno, 2016. http://hdl.handle.net/10556/2612.
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2015 - 2016<br>Nowadays, the analysis of issues associated with road traffic within urban and suburban areas has
taken a leading role in trying to implement efficient plans of transport regulations by taking
advantage of the available infrastructure.
In fact, the occurrence frequency of slowdowns phenomena and strong congestions has greatly
multiplied and caused a series of inconveniences and poor services for citizens such as the increased
risk of accidents and air and noise pollution.
In order to solve the problem of urban mobility, it is possible to act with a rational management of
infrastructure and a road artery-planning program using simulators able to identify critical points in
the design phase and evaluate the correctness of the proposed interventions. For this reason, it is
important to use mathematical models to predict the evolution of the traffic starting from the
knowledge of quantities such as cars’ densities at a given time instant.
These models are classified into microscopic and macroscopic ones. The former analyze the behavior
of each single vehicle, while the latter consider situations that arise from the interaction of many
particles derived based on concepts of the fluid dynamics.
The aim of the present research work is to review macroscopic fluid dynamic models dealing with
traffic flow on road networks and to propose new solutions for the dynamics at intersections based
on the integration of optimization criteria about the vehicular flow and rules for the distribution of
traffic.
In detail, the Thesis analyzes, describes and highlights the following topics and results: physical variables that regulate road traffic and the relation that links them with each other,
and some fluid dynamic macroscopic models for traffic on a single road (i.e. LWR, Payne
Whitham, Aw-Rascle, Zhang, Third order and Multilane models); vehicular traffic network based on the fluid dynamic model LWR and conservation laws,
and characterized by some aspects to be solved like initial conditions on not infinite roads
and dynamics at intersections. About the former aspect, the corresponding boundary value
problems are presented and solved, while about the latter aspect the solution to Riemann
Solver is given by considering also additional rules for traffic distribution that are well
defined in new appropriate models simulating the presence of traffic lights at intersections
with variable or fixed cycles of red-green; numerical schemes used for the discretization of the conservation law and the solution of
the dynamic at intersections. In detail, Godunov scheme, used for the determination of
density values for road sections in different time instants starting from the initial density
value of each road on the analyzed road network, is considered; numerical results about an experimentation of some of the new models defined that are
implemented within a road traffic simulator prototype by reproducing the behavior of
vehicular densities on a road network with appropriate dynamics at intersections. These
results are then compared in order to prove the correctness of each model, evaluate the
performances and analyze some specific situations for optimization of car traffic.
Considerations and results obtained in this research work by simulation of traffic flows may be
useful as support for authorities responsible for urban road network in order to make an appropriate
urban planning by evaluating the needs of the country. In fact, it could be possible to avoid traffic
congestion at certain areas or time slots, bring down the rate of air pollution or noise and minimize
risks due to overcrowding of vehicles on roads. [edited by author]<br>Oggigiorno, l'analisi delle problematiche legate al traffico stradale nelle aree urbane e suburbane ha
avuto un ruolo di primo piano nel tentativo di attuare piani efficienti di regolamentazione dei
trasporti sfruttando le infrastrutture disponibili.
Infatti, la frequenza dei fenomeni di rallentamento e di congestione si è moltiplicata e ha causato
una serie di inconvenienti e scarsi servizi per i cittadini, come l'aumento del rischio di incidenti e di
inquinamento atmosferico ed acustico.
Al fine di risolvere il problema della mobilità urbana, è possibile agire con una gestione razionale
delle infrastrutture e un programma di pianificazione dell'arteria stradale utilizzando simulatori in
grado di individuare punti critici nella fase di progettazione e valutare la correttezza degli interventi
proposti. Per questo motivo, è importante utilizzare modelli matematici per prevedere l'evoluzione
del traffico a partire dalla conoscenza di quantità come la densità di un veicolo in un dato istante di
tempo.
Tali modelli sono classificati in microscopici e macroscopici. I primi analizzano il comportamento di
ogni singolo veicolo, mentre i secondi considerano situazioni che derivano dall'interazione di molte
particelle derivate in base ai concetti della fluido-dinamica.
Lo scopo del presente lavoro di ricerca è quello di analizzare i modelli fluido-dinamici macroscopici
che trattano il flusso di traffico sulle reti stradali e di proporre nuove soluzioni per le dinamiche agli
incroci basate sull'integrazione di criteri di ottimizzazione del flusso veicolare con regole di
distribuzione del traffico.
In dettaglio, la tesi analizza, descrive ed evidenzia i seguenti argomenti e risultati: le variabili fisiche che regolano il traffico stradale e la relazione che le lega tra loro, ed alcuni
modelli fluido-dinamici macroscopici per il traffico su singola strada (ovvero i modelli LWR,
Payne-Whitham, Aw-Rascle, Zhang, Third order e Multilane); la rete di traffico veicolare basata sul modello fluido-dinamico LWR e sulle leggi di
conservazione e caratterizzata da alcuni aspetti da risolvere come le condizioni iniziali sulle
strade non infinite e le dinamiche agli incroci. Per quanto riguarda il primo aspetto, vengono
presentati e risolti i problemi di “condizione al bordo” corrispondenti, mentre per quanto
riguarda il secondo aspetto viene presentata la soluzione al problema di Riemann
considerando anche regole aggiuntive e ben definite per la distribuzione del traffico in
nuovi modelli che simulano la presenza di semafori agli incroci con cicli variabili o fissi di
rosso-verde;
gli schemi numerici per la discretizzazione della legge di conservazione e la soluzione alle
dinamiche agli incroci. In dettaglio, viene considerate lo schema di Godunov, usato per
determinare i valori di densità dei segmenti di strada in diversi istanti di tempo a partire dal
valore di densità iniziale di ogni strada nella rete stradale analizzata; i risultati numerici della sperimentazione di alcuni dei nuovi modelli definiti, che sono
implementati all’interno di un prototipo di simulatore del traffico stradale riproducendo il
comportamento delle densità dei veicoli nella rete stradale con appropriate dinamiche agli
incroci. Tali risultati sono successivamente confrontati per provare la correttezza di ogni
modello, valutare le prestazioni e analizzare alcune specifiche situazioni per ottimizzare il
traffico stradale.
I risultati e le considerazioni emerse dal presente lavoro di ricerca simulando flussi veicolari possono
essere di aiuto alle autorità responsabili della rete stradale urbana per progettare un efficiente
piano di viabilità valutando le reali necessità della città. Infatti, si potrebbero evitare congestioni di
traffico in certe aree della città o in specifici intervalli temporali, diminuire sostanzialmente il tasso
di inquinamento atmosferico o acustico e minimizzarne i rischi dovuti al sovraffollamento di veicoli
lungo le strade. [a cura dell'autore]<br>XV n.s.
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McBride, Diane. "Vertex-based discretisation methods for thermo-fluid flow in a finite volume-unstructured mesh context." Thesis, University of Greenwich, 2003. http://gala.gre.ac.uk/6246/.
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The main aim of this research project is to investigate techniques to improve the resolution of flow variables on unstructured skewed meshes whilst working within a Finite Volume (FV) context. A three-dimensional vertex-based FV algorithm for the solution of thermo- fluid flow problems has been developed and integrated within a multi-physics FV framework PHYSICA. Currently PHYSICA employs a cell-centred discretisation technique for fluid mechanics problems and a vertex-based discretisation technique for solid mechanics problems. The vertex-based discretisation approach is validated for a variety of heat transfer problems and comparisons are made with cell-centred solutions. A coupled thermo-mechanical problem, including solidification and radiation, is simulated using vertex-based and cell-centred techniques. Results, run-time and memory requirements are compared. Hybrid vertex-based/cell-centred discretisation of the hydrodynamic variables is also investigated. The components of velocity are solved vertex-based with pressure cell-centred or conversely pressure is solved vertex-based with velocity cell-centred. The methods are applied to flow in a lid-driven cavity and solutions are obtained on a number of distorted meshes. Comparisons are made with the benchmark solutions. The hybrid discretisation enables solutions on distorted meshes where purely cell-centred techniques fail. The hybrid methods produce final solutions containing errors due to mesh distortion. The co-located vertex-based flow solutions obtained on the distorted meshes are comparable to solutions obtained on a uniform Cartesian mesh. Having a good resolution of the flow field on distorted meshes enables the solution of other transported variables using cell-centred techniques. Finally, this hybrid vertex-based/cell-centred technique is applied to thermally driven flow, turbulent flow, and three-dimensional flow over an aircraft wing.
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Seddiki, Sélim. "Contribution au développement du détecteur de Vertex de l'expérience CBM et étude de faisabilité des mesures du flot elliptique des particules à charme ouvert." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00862654.
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CBM, une des expériences majeures du nouvel accélérateur FAIR en cours de construction au GSI (Darmstadt), a pour objectif d'explorer le diagramme des phases de la matière nucléaire dans la région des hautes densités baryoniques nettes. Un de ses principaux thèmes de physique est l'étude de la production des particules à charme ouvert dans les collisions d'ions lourds. La mesure directe de ces particules nécessite l'utilisation d'un détecteur de vertex très précis. La présente thèse est une contribution à la conception et au développement de ce détecteur, appelé MVD. Une première partie de la thèse concerne l'évaluation, à l'aide de simulations réalistes, des flots de données à transmettre par les capteurs qui équiperont la première génération du MVD. Les résultats obtenus montrent que les performances attendues des capteurs permettront de mener à bien le programme de physique de CBM. Une deuxième partie porte sur les performances attendues pour la reconstruction des particules à charme ouvert, à travers leur désintégration hadronique, dans les collisions Au+Au. Des simulations détaillées ont permis de démontrer que la reconstruction du méson D+ → π+ π+ K-, par exemple, est faisable avec une efficacité de reconstruction de 2% et un rapport signal/bruit de 1.5. La statistique attendue en deux mois de prises de données a été évaluée à environ 6.9 x 104 mésons D. Dans la dernière partie, il a été montré que cette statistique permettrait d'effectuer des études détaillées du flot elliptique intégré des mésons D. La mesure du flot elliptique différentiel de ces particules requerrait, cependant, des statistiques plus élevées, et donc l'utilisation de capteurs plus performants.
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Ravikumar, Devaki. "2D Compressible Viscous Flow Computations Using Acoustic Flux Vector Splitting (AFVS) Scheme." Thesis, Indian Institute of Science, 2001. http://hdl.handle.net/2005/277.
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The present work deals with the extension of Acoustic Flux Vector Splitting (AFVS) scheme for the Compressible Viscous flow computations. Accurate viscous flow computations require much finer grids with adequate clustering of grid points in certain regions. Viscous flow computations are performed on unstructured triangulated grids. Solving Navier-Stokes equations involves the inviscid Euler part and the viscous part. The inviscid part of the fluxes are computed using the Acoustic Flux Vector Splitting scheme and the viscous part which is diffusive in nature does not require upwinding and is taken care using a central difference type of scheme. For these computations both the cell centered and the cell vertex finite volume methods are used. Higher order accuracy on unstructured meshes is achieved using the reconstruction procedure. Test cases are chosen in such a way that the performance of the scheme can be evaluated for different range of mach numbers. We demonstrate that higher order AFVS scheme in conjunction with a suitable grid adaptation strategy produce results that compare well with other well known schemes and the experimental data. An assessment of the relative performance of the AFVS scheme with the Roe scheme is also presented.
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Green, Steven. "Calorimetry at a future Linear Collider." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/269648.
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This thesis describes the optimisation of the calorimeter design for collider experiments at the future Compact Linear Collider (CLIC) and the International Linear Collider (ILC). The detector design of these experiments is built around high-granularity Particle Flow Calorimetry that, in contrast to traditional calorimetry, uses the energy measurements for charged particles from the tracking detectors. This can only be realised if calorimetric energy deposits from charged particles can be separated from those of neutral particles. This is made possible with fine granularity calorimeters and sophisticated pattern recognition software, which is provided by the PandoraPFA algorithm. This thesis presents results on Particle Flow calorimetry performance for a number of detector configurations. To obtain these results a new calibration procedure was developed and applied to the detector simulation and reconstruction to ensure optimal performance was achieved for each detector configuration considered. This thesis also describes the development of a software compensation technique that vastly improves the intrinsic energy resolution of a Particle Flow Calorimetry detector. This technique is implemented within the PandoraPFA framework and demonstrates the gains that can be made by fully exploiting the information provided by the fine granularity calorimeters envisaged at a future linear collider. A study of the sensitivity of the CLIC experiment to anomalous gauge couplings that {affect} vector boson scattering processes is presented. These anomalous couplings provide insight into possible beyond standard model physics. This study, which utilises the excellent jet energy resolution from Particle Flow Calorimetry, was performed at centre-of-mass energies of 1.4 TeV and 3 TeV with integrated luminosities of 1.5$\text{ab}^{-1}$ and 2$\text{ab}^{-1}$ respectively. The precision achievable at CLIC is shown to be approximately one to two orders of magnitude better than that currently offered by the LHC. In addition, a study into various technology options for the CLIC vertex detector is described.
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Rudgyard, Michael A. "Cell vertex methods for compressible gas flows." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279991.
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Vašek, Lubomír. "Trhání vodního sloupce pod OK vodní turbíny při nestacionárních stavech." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230024.
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In this diploma thesis called Water column separation under the hydraulic turbine runner during unsteady operating regimes are solved the pressure pulsations of the reverse water hamer. In the thesis is deduced a mathematical relationship of elaboration the numerice model which is based on equations of continuity and equations of forces equilibrium. Numerical model is created in MS Excel uses for computation the numerical method Lax-Wendrof that allows consideration of variable sound speed as function of static pressure and allows variable lenght step in computation domain. Reverse water hammer is in the thesis solved with consideration of rotating flow behind shut-off valve, where we expect forming of vortex rope. This situation can be applied on the closing water turbine which has vertex rope under turbine runner. Specifically for this thesis was carried out the experiment of the reverse water hammer. Constants going into numerical solution are optimalized with using experiment and pressure pulsation are compared between numerical solution and experiment.
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Håkansson, Jacob, and Isidora Vakaricic. "Produktionsflödesanalys - CA-Verken i Sävsjö." Thesis, Växjö University, School of Technology and Design, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1536.
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<p>Examensarbete utfördes på CA-Verken i Sävsjö som bl.a. tillverkar hydraulcylindrar. De senaste två år har CA-Verken haft en kraftig ökning av omsättningen och det som står i vägen för fortsatt expansion är produktionen som har begränsad kapacitet.</p><p>Målet med detta arbete är att studera CA-Verkens produktionsflöde för att kunna identifiera flaskhalsen/flaskhalsarna och därefter ge förslag på lösningar och förbättringar. Den teorin som har använts som grund till arbetet är Theory of Constraints (TOC). Intervjuer, företagets affärssystem och observationer har använts vid datainsamling. Genom analysering av produktionsflödet för cylindrar som står för den största delen av omsättningen identifierades monteringen som flaskhals.</p><p>För att kunna optimera produktionsflödet krävs det att monteringen utnyttjas effektivt samt att olika störningar och slöserier i monteringsprocessen elimineras.</p><br><p>This diplomawork is a study of the making of hydraulic cylinders at CA-Verken, a Swedish company located in Sävsjö. The last two years has showed a substantial increase of the company’s turnover. The only remaining obstacle of an ongoing expansion is the limited capacity of the company’s production.</p><p>The purpose of this diplomawork is, for that particular reason, to study CA-Verkens production flow in order to identify the bottleneck-issues and ultimately be able to suggest possible solutions and improvements concerning the production process.</p><p>The theoretic foundation of this study is based on the Theory of Constraints (TOC). Interviews, company business systems and observations have been used as important sources during the collection of data. By analysing the production flow concerning the cylinders, which represents the greatest deal of the company’s turnover, the assembly was identified as a bottleneck-issue.</p><p>In order to optimize the torrent of production it’s necessary for the company to increase the efficiency of the assembly and eliminate different disturbances as well as all unnecessary wastefulness in the process.</p>
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Benamara, Nassima. "Intensification de procédés par chauffage micro-ondes pour la chimie verte." Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR13.
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L'objet de cette thèse est la conception, le développement et la caractérisation d'un réacteur micro-ondes en continu pour mener tout type de réactions chimiques à températures élevées de manière fiable et dans des conditions optimisées. Le développement de ce réacteur a tout d'abord nécessité la caractérisation diélectrique et magnétique des matériaux et milieux utilisés. La simulation numérique a ensuite été utilisée afin de prédire les distributions de champ et température au sein des matériaux. L'interaction entre les ondes et les différents milieux a été finement étudiée. Elle démontre non seulement l'influence de la nature diélectrique du milieu réactionnel et du ratio volumique du fluide dans le réacteur sur le chauffage micro-ondes, mais aussi celle des dimensions de l'applicateur et de la disposition du réacteur dans ce dernier. L'hydrodynamique a également été introduite dans la simulation permettant de prédire les profils de température dans le réacteur en fonctionnement continu. L'ensemble des résultats numériques a fait l'objet de validations expérimentales qui ont aussi permis d'affiner le modèle thermique de l'ensemble conçu. Au final, une réaction de diestérification a été mise en œuvre et démontre l'efficacité thermique et chimique du réacteur. Au-delà de ce prototype, cette thèse établit un schéma général de conception d'un procédé chimique continu sous micro-ondes en ordonnant les étapes, respectant les règles clés de l'électromagnétisme, optimisant la propagation des ondes et les performances thermiques du système<br>The aim of this thesis is the development and characterisation of an intensified continuous microwave reactor for green chemistry. The development of this reactor required, at first, the characterisation of the dielectric and magnetic properties of the used materials. A numerical simulation was then used to predict the field and temperature profiles within the materials. The influence of different parameters on the microwave heating was also studied, such as the influence of the dielectric nature of the reaction medium, the ratio of the fluid in the reactor, the arrangement of the reactor in the applicator and the size and shape of the latter. Hydrodynamics were also taken into account in the simulation to predict the temperature profiles in the reactor. All the numerical results were validated experimentally. Experimental results also made it possible to refine the thermal model of the reactor. In the end, an esterification reaction was carried out and it proved the thermal and chemical efficiency of the designed reactor. Beyond this prototype, this thesis establishes a general scheme for the design of a continuous chemical process under microwaves whilst following the key rules of electromagnetism and optimising the wave propagation and the thermal performance of the reactor
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Guichard, Cindy. "Schémas volumes finis sur maillages généraux en milieux hétérogènes anisotropes pour les écoulements polyphasiques en milieux poreux." Phd thesis, Université Paris-Est, 2011. http://tel.archives-ouvertes.fr/tel-00674503.
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Cette thèse est consacrée à l'étude de méthodes numériques pour la simulation des écoulements polyphasiques en milieu poreux, en vue de leur application à des problèmes d'ingénierie pétrolière ou environnementale. Nous présentons une formulation générique du modèle d'écoulements à nombre quelconque de composants présents dans un nombre quelconque de phases. Dans notre approche l'approximation des flux diffusifs (issus, par exemple, de la loi de Darcy) s'appuie sur de nouveaux schémas, appelés schémas gradient, qui ont plusieurs avantages sur les schémas industriels standard : ces derniers, qui sont des schémas volumes finis multi-points centrés aux mailles, ne sont généralement pas symétriques et convergent difficilement sur des cas à forts rapports d'anisotropie. Nous montrons en revanche que les schémas gradient conduisent naturellement à des approximations symétriques et convergentes. Parmi cette classe de schémas, nous étudions plus particulièrement le schéma "VAG" qui fait intervenir des inconnues au centre des mailles et aux sommets du maillage. Ce schéma conduit à la définition de flux entre le centre d'une maille et ses sommets, qui sont utilisés pour généraliser la méthode "VAG" au contexte polyphasique. Des tests numériques montrent alors que ce schéma est robuste, et conduit à un très bon compromis précision/coût, ce qui en fait un candidat idoine pour les applications industrielles. Nous présentons notamment un cas test, basé sur des observations de terrains, d'injection et de dissolution de CO2 dans la région proche d'un puits foré dans un aquifère salin. Nous montrons alors que le schéma numérique permet de simuler l'assèchement et la précipitation de minéral observée en pratique. Un chapitre de la thèse est enfin consacré à l'étude pratique et théorique d'une méthode numérique générique pour contrôler l'effet d'axe lors de l'utilisation de schémas industriels
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Giering, Kay-Uwe [Verfasser], and Manfred [Akademischer Betreuer] Salmhofer. "Self-energy flows and the frequency-dependent interaction vertex in the two-dimensional repulsive Hubbard model / Kay-Uwe Giering ; Betreuer: Manfred Salmhofer." Heidelberg : Universitätsbibliothek Heidelberg, 2012. http://d-nb.info/1179784901/34.
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Peterson, Olga Yuris. "Transferring pharmaceutical batch technology to continuous flow." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39510.
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The current trend in the pharmaceutical industry is towards continuous flow processes. Continuous flow reactor technology can produce a cheaper, better quality product at reduced energy and environmental cost through more efficient mass and heat transfer. It also enables a simplified and faster approach to bulk production by scaling out as opposed to scaling up. The research presented here focuses on the configuration and installation of a continuous flow system into the laboratory, and the transfer of a Meerwein-Ponndorf-Verley (MPV) reduction from batch to continuous mode.
The Corning® glass continuous flow reactor in our laboratory utilizes specially-designed mixing structures for enhanced mass transfer. Additionally, the glass reactor offers nonreactivity and corrosion resistance over a wide range of temperature and pressure, which conventional steel reactors do not allow. The MPV reduction is a well-known method to prepare primary and secondary alcohols from aldehydes and ketones, respectively. The traditional MPV reduction protocol (Al(OiPr)₃ in isopropanol) was modified to enable the technological transfer from batch to continuous mode. This is the first time MPV reduction reactions were carried out in continuous mode. As a result, the MPV reduction of the model compound, benzaldehyde, was successfully conducted with 60% less catalyst and product yield was improved up to 20% (average of 10%) in continuous flow reactions as compared to current batch technology. These results are being used to develop a technology roadmap for the pharmaceutical industry to implement continuous flow processes in their manufacturing operations.
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Hall, Rosario R. "Fronteras de la Modernidad y la Posmodernidad en la 'Flor de Lis' y Hasta No Verte Jesús Mío." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/243691.
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The present dissertation discusses primary dichotomies in discourses, cultural and economic practices which operate to entrench divisions and fetter notions of identity in two of Elena Poniatowska's (b. 1932) novels: La 'Flor de Lis' (1988) and Hasta no verte Jesús mío (1969). More specifically, this study has taken relevant concepts provided by Cultural Studies, such as power and hegemony, in order to bring forward questions of economic transnationalism and cultural practices in the main characters. Through the parameters of deconstruction and demythologization we interrogate how binary oppositions such us the paradigms of Modernity and Postmodernity converge in Poniatowska's works. We observe that notions of logocentrism are present in the friendship between two of the characters in La 'Flor de Lis': on one side, there is Magda the peripheral subject, whose orality permeates Mariana's lettered culture. Thus, we establish the connection between the city and Modernity, and at the same time, we emphasize how the Other's voice, under the paradigm of Modernity, is associated with barbarians, while under Postmodernity it acquires a space among hegemonic forces. In both novels we notice how, after the Revolution (1910), the Mexican state generates a modernizing project by fomenting the idea of a modern national subject; this is done in order to transcend social fragmentation. The process that Étienne Balibar denominates fictive ethnicity helps the State to create a national- popular representation based in the triad formed by a shared language, history and origins; however, the four characters in Poniatowska's novels do not comply with the State's efforts. Instead, they challenge those representations that ultimately expose the failure of the two main grand narratives: Modernity (the idea of progress and equality), and the Nation. In conclusion, we emphasize that the dialogue between the characters in Hasta no verte Jesús mío and La 'Flor de Lis' completes a circle in which Magda is the liberating trigger for Mariana's actions, as Jesusa is for Poniatowska. In particular, social differences between Mariana and Jesusa make possible a reading in which they not only establish a dialogue but also, through that dialogue, the reader may observe economic and social structures through two paradigms: Modernity and Postmodernity.
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Sergent, Anne-Sophie. "Biominéralisation et réactivité de la rouille verte carbonatée par shewanella putrefaciens en système hétérogène fermé et en écoulement continu." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0355/document.
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Les rouilles vertes sont des hydroxysels mixtes Fe(II)-Fe(III) présents dans les sols hydromorphes sous forme de fougérite. Elles sont connues pour être capable de réduire des polluants organiques et métalliques. Les rouilles vertes peuvent être produites à partir de la bioréduction de lépidocrocite [gamma]-FeOOH par Shewanella putrefaciens, une bactérie ferriréductrice. En vue de comprendre leur formation dans l'environnement et d'utiliser leur réactivité dans la mise en place, à terme, d'un système de dépollution des sols et des eaux (colonne de sable), nous avons étudié leur formation dans un système en batch en présence d'une phase siliceuse (sable et acide silicique) et en présence de polymères organiques synthétiques (polyacrylate PAA et polyacrylamide PAM) afin de mimer la présence des corps bactériens. La silice est les polymères apparaissent comme de bons agents stabilisateurs, favorables à la formation des rouilles vertes. Les rouilles vertes formées en présence de ces agents stabilisateurs conservent leur capacité réductrice vis-à-vis d'un polluant organique, le rouge de méthyle et d'un polluant métallique, le mercure Hg2+. Nous avons ensuite transposé notre système en batch dans une colonne de sable + lépidocrocite [gamma]-FeOOH, soumise à un régime hydrodynamique. Nous avons réussi à former et à caractériser une rouille verte comme minéral secondaire de la bioréduction de la lépidocrocite par Shewanella putrefaciens<br>Green rusts are mixed species Fe(II)-Fe(III) present in hydromorphic soils as fougerite. They are capable to reduce organic and metallic pollutants. Green rusts may be produced from the bioreduction of lepidocrocite [gamma]-FeOOH by Shewanella putrefaciens, a dissimilatory iron reducing bacteria. In order to understand their formation routes in the environment and eventually, use their reactivity in a system for soil and water remediation (sand column), we studied their formation in a batch system with silica phase (quartz sand and silicic acid) and with two organic polymers (PAA polyacrylate and polyacrylamide PAM).The silica polymers appear to be good stabilizers, favorable to the formation of green rusts. Green rusts formed in the presence of the stabilizing agents retain their reductive capacity toward an organic pollutant, methyl red and a metallic pollutant, mercury Hg2+. Then, we have transposed our system in a flow through column of sand + lepidocrocite [gamma]-FeOOH. The carbonate green rust was formed and identified as secondary mineral of lepidocrocite bioreduction by Shewanella putrefaciens
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Hallot, Gauthier. "Synthèse, caractérisations et vectorisation des nanoparticules de bismuth métallique pour des applications théranostiques." Thesis, Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=http://theses-intra.upmc.fr/modules/resources/download/theses/2019SORUS272.pdf.
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Les nanoparticules de bismuth métallique sont peu décrites dans la littérature et pourtant elles ont un fort potentiel médical. Leur utilité est notamment décrite dans des applications thérapeutiques et/ou diagnostiques De plus, le bismuth est un élément abondant, peu cher et biocompatible. Dans ce projet, une synthèse robuste et reproductible de nanoparticules de bismuth métallique dans l’eau en procédé non continu a été développée en appliquant les principes de la nanochimie verte. Cette synthèse a ensuite été transférée en procédé continu pour augmenter la productivité d’obtention des nanoparticules. La caractérisation de leur surface, leur stabilité chimique et colloïdale ainsi que leur cytotoxicité ont été étudiées afin d’envisager leur utilisation en milieu biologique. Trois types de nanoparticules hydrophiles, hydrophobes et fluorophiles ont été obtenues après l’échange de ligand. Les nanoparticules hydrophiles ayant à leur surface du polyéthylène glycol sont stables pendant 24 heures dans le sérum physiologique. Les nanoparticules hydrophobes ont été incorporées dans des émulsions huile dans eau. En revanche, les nanoparticules polyfluorées ne contenant pas assez de fluor sur l’agent de revêtement n’ont pas pu être incorporées dans une huile fluorée. Enfin, une étude préliminaire n’a pas permis de montrer un effet de radiosensibilisation des nanoparticules de bismuth. Des études approfondies in vitro et in vivo de ces nanoparticules sont envisagées pour conclure définitivement sur leur effet radiosensibilisant<br>Metallic bismuth nanoparticles are poorly described in the literature and yet they have a high medical potential. Their utility is particularly described in therapeutic and/or diagnostic applications. In addition, bismuth is an abundant, inexpensive and biocompatible element. In this project, a robust and reproducible synthesis of metallic bismuth nanoparticles in water in a non-continuous process was developed by applying the principles of green nanochemistry. This synthesis was then transferred to a continuous process to increase the productivity of obtaining nanoparticles. The characterization of their surface, chemical and colloidal stability as well as their cytotoxicity were studied in order to consider their use in biological environments. Three types of hydrophilic, hydrophobic and fluorophilic nanoparticles have been obtained. Hydrophilic nanoparticles with polyethylene glycol on their surface are stable for 24 hours in saline solution. Hydrophobic nanoparticles have been incorporated into oil-in-water emulsions. On the other hand, polyfluorinated nanoparticles containing insufficient fluorine on the coating agent could not be incorporated into a fluorinated oil. Finally, a preliminary study did not show a radiosensitization effect of bismuth nanoparticles. In vitro and in vivo studies of these nanoparticles are planned to definitively conclude on their radiosensitizing effect
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Wang, Yantao. "Synthesis and conversion of furfural-batch versus continuous flow." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2474/document.
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Le furfural, identifié comme l'un des 30 principaux produits chimiques biologiques, est une molécule importante en terme de chimie verte et développement durable. L'objectif de ce travail de doctorat est de réaliser la synthèse et la conversion du furfural en flux continu et par lots. Ici, nous avons développé des méthodes plus éco-efficiente pour la synthèse du furfural, et valorisé le furfural en produits à haute valeur ajoutée, tels que le 2-furonitrile, l'alcool furfurylique, etc... Plusieurs questions clés ont été identifiées afin de concevoir des processus plus écologiques que les processus actuels. En détail, des expériences de synthèse du furfural ont été réalisées dans l'eau pure ou dans un mélange eau-solvants organiques lorsque des co-solvants (verts ou écologiques) sont nécessaires. L'irradiation par micro-ondes a été choisie comme méthode de chauffage pour accélérer le processus de déshydratation, et un réacteur à flux continu à micro-ondes a également été utilisé pour améliorer la productivité du furfural. En partant du furfural pour produire des produits chimiques à haute valeur ajoutée, des réacteurs à flux efficace, tels que Pheonix, H-cube Pro ainsi que des micro-ondes à flux continu avec micro-réacteur, ont également été identifiés comme des alternatives intéressantes pour améliorer la productivité des composés cibles. En conséquence, certains résultats prometteurs ont été obtenus du point de vue de l'industrie<br>Furfural, which has been identified as one of top 30 bio-based chemicals, is an important green platform molecule, The aim of this PhD work is to realize the synthesis and conversion of furfural in batch and continuous flow. Here, we developed sorne greener methods for furfural synthesis, and valorized furfural into high value-added products, such as 2-furonitrile, furfuryl alcohol etc. Several keys issues were identified in order to design processes greener than the current ones. ln detail, experiments for furfural synthesis were performed in water or in water and organic solvent when co-solvents (green or eco-friendly) are necessary. Microwave irradiation has been chosen as the heating method to accelerate the dehydration process, and microwave continuous flow reactor was also applied to improve furfural productivity. When starting from furfural to produce high value-added chemicals, efficient flow reactors, suc as Pheonix, H-cube Pro as well as microwave continuous flow With micro-reactor, were also identified as interesting alternatives to improve the productivities of target compounds. As a result, some promising results were obtained in the viewpoint of industry
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LIMA, Edson Ferreira de. "Produtividade e rentabilidade da alface adubada com flor de seda." Universidade Federal Rural de Pernambuco, 2012. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6135.
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Previous issue date: 2012-12-03<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES<br>The production of vegetables is an impacting activity, which is characterized by intensive use of land, with high demand of inputs and requires adoption of strategic management with agroecological approach to sustain its production. Two experiments were conducted in the experimental area Universidade Federal Rural de Pernambuco (UFRPE) - Unidade Acadêmica de Serra Talhada (UAST), Serra Talhada – PE (Brazil), with the objective of evaluating the production of lettuce for different amounts of time and soil incorporation of Flor de Seda (Calotropis procera) two growing seasons. The experiments were conducted in two periods: the first was conducted in the dry season of 2011 (September-November) and the second during the rainy season of 2012 (May to July), In a randomized complete block design with treatments arranged in a factorial 4 x 4 + 2, with three replications, with the first factor consisting of different amounts of green manure incorporated into the soil (5.4, 8.8, 12, 2 and 15.6 t ha-1 on a dry basis) and the second factor for different times of incorporation of this fertilizer to the soil (0, 10, 20, and 30 days) plus two additional treatments, a fertilizing the absence of the other by use of 80 t ha-1 cattle manure. The lettuce cultivation used was Nanny summer, with spacing of 0,20 m x 0,20 m. The characteristics evaluated were plant height and diameter, number of leaves per plant, green mass yield and dry mass of shoots, plus some economic indicators such as gross income, net income, rate of return and profitability index. The best performances Agroeconomic lettuce were observed in the amount of 15.6 t ha-1 green manure Flor de seda in two cropping seasons, with the best results the time of incorporation of 0 days in the dry season and 20 days in the incorporation in rainy season.<br>A produção de hortaliças é uma atividade impactante, que se caracteriza pelo uso intensivo do solo, alta demanda de insumos e requer adoção estratégica de manejo com enfoque agroecológico de modo a sustentar sua produção. Dois experimentos foram conduzidos na área experimental da Universidade Federal Rural de Pernambuco (UFRPE) - Unidade Acadêmica de Serra Talhada (UAST), Serra Talhada - PE, com o objetivo de avaliar a produção de alface em função de diferentes quantidades e tempos de incorporação ao solo de Flor de seda (Calotropis procera) em duas épocas de cultivo. Os experimentos foram conduzidos em dois períodos: o primeiro foi realizado no período seco de 2011 (setembro a novembro) e o segundo no período chuvoso de 2012 (maio a julho), em delineamento experimental de blocos completos casualizados com os tratamentos arranjados em esquema fatorial 4 x 4 + 2, com três repetições, sendo o primeiro fator constituído por diferentes quantidades de adubo verde incorporadas ao solo (5,4; 8,8; 12,2 e 15,6 t ha-1 em base seca) e o segundo fator, por diferentes tempos de incorporação deste adubo ao solo (0, 10, 20, e 30 dias) mais dois tratamentos adicionais, um pela ausência de adubação e o outro pela utilização de 80 t ha-1de esterco bovino. A cultivar de alface utilizada foi a Babá de Verão, com espaçamentos de 0,20m x 0,20m. As características avaliadas foram altura e diâmetro de plantas, número de folhas por planta, rendimento de massa verde e massa seca da parte aérea, além dos indicadores econômicos renda bruta, renda líquida, taxa de retorno e índice de lucratividade. Os melhores desempenhos agroeconômicos da alface foram observados na quantidade de 15,6 t ha-1 de adubo verde Flor de seda nas duas épocas de cultivo, tendo como melhores resultados o tempo de 0 dia de incorporação na época seca e 20 dias de incorporação na época chuvosa.
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SOUSA, José da Silva. "Jitirana, flor-de-seda e mata-pasto como fonte de adubo verde na produtividade do coentro." Universidade Federal de Campina Grande, 2014. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/844.
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Previous issue date: 2014-11-11<br>O coentro (Coriandrum sativum L.) é uma olerícola herbácea anual com altura média de 10 a 20 cm planta-1, dependendo das condições edáficas que esteja sendo cultivado, da cultivar e adubação. O seu cultivo é principalmente voltado para atender à demanda para o consumo fresco de hastes e para as indústrias de condimentos. Nesse sentido a pesquisa objetivou avaliar a jitirana (Merremia aegyptia), flor-de-seda (Calotropis procera) e mata-pasto (Senna uniflora) como fonte de adubo verde no desempenho agroeconômico do coentro. O experimento foi conduzido na Fazenda Experimental Rafael Fernandes, localizada no distrito de Alagoinha, zona rural de Mossoró-RN, no período de julho a setembro de 2013. O delineamento experimental utilizado foi em blocos completos casualizados, com os tratamentos arranjados em esquema fatorial 4 x 3, com 3 repetições. Os tratamentos consistiram da combinação de quatro quantidades de espécies espontâneas (0,4; 0,8; 1,2 e 1,6 kg/m2) e o segundo fator, correspondendo a três tipos de espécies espontâneas (jitirana, flor-de-seda e mata-pasto). Cada parcela constou de doze fileiras de plantas espaçadas de 0,1 m x 0,05 m, com 05 plantas cova-1. Dez dias após a emergência realizou-se o desbaste, trinta e três dias após o plantio foi realizada a colheita. As características avaliadas foram as seguintes: altura de planta, número de hastes por planta, massa fresca de coentro, massa seca de coentro e
número de molhos de coentro, os parâmetros econômicos foram: Renda bruta, renda
líquida, taxa de retorno por real investido e índice de lucratividade. Para altura de planta
em relação aos tipos de adubos verdes, observou-se diferença da jitirana em relação a florde-
seda e mata-pasto, com valores médios de 18,9; 16,8 e 16,0 cm planta-1. Para a massa
fresca, observou-se que a jitirana foi superior à flor-de-seda e mata-pasto, com
produtividade máxima de 0,9; 0,7 e 0,8 kg m-2 de canteiro, equivalente a 18, 14 e 16
molhos m-2 de canteiro, na quantidade de 16,0 t ha-1. A aplicação de espécies espontâneas
da caatinga, proporcionou rentabilidade líquida de R$ 6.070,00, taxa de retorno da ordem
de R$ 2,80 e índice de lucratividade de 64,2% para jitirana. Rentabilidade líquida de R$
2.920,00, taxa de retorno de 1,86 e índice de lucratividade de 46,3% para a flor-de-seda e
rentabilidade líquida de R$ 4.270,00, taxa de retorno de 2,26 e índice de lucratividade de
55,8%. Nesse sentido, o cultivo de coentro adubado com espécies espontâneas da caatinga
constitui-se em alternativa como adubo verde.<br>Coriander (Coriandrum sativum L.) is an annual herbaceous vegetable crop
with average height 10-20 cm plant-1, depending on the soil conditions that are being
grown, cultivar and fertilization. Its cultivation is mainly geared to meet the demand for
fresh consumption stems and condiments industries. In this sense the research aimed to
evaluate the jitirana (Merremia aegyptia), silk-flower (Calotropis procera) and kills
pasture (Senna uniflora) as a source of green manure on agroeconomic performance of
cilantro. The experiment was conducted at the Experimental Farm Rafael Fernandes,
located in the district of Alagoinha, rural area of Mossoró-RN, in the period from July-
September 2014. The experimental design was complete randomized block with treatments
arranged in a factorial 4 x 3, with 3 repetitions. Treatments included a combination of four
amounts of wild species (0,4; 0,8; 1,2 e 1,6 kg/m2) and the second factor, corresponding to
three types of spontaneous species (jitirana, silk-flower and bush-pasture). Each plot
consisted of twelve rows of plants spaced 0,1 mx 0,05 m, with 05 plants pit-1. Ten days
after germination thinning took place thirty-three days after the planting to harvest was
performed. The characteristics evaluated were: plant height, number of stems per plant,
fresh coriander mass, dry mass and number of bunches cilantro coriander, economic
parameters were: gross income, net income, rate of return per dollar invested and
profitability index. Plant height in relation to the types of green manures, a difference was
observed in relation to the jitirana-flowered silk-flower and bush-pasture, with average
values of 18.9; 16.8 and 16.0 cm plant-1. For fresh pasta, it was observed that the jitirana
was superior to silk-flower and bush-pasture and woods with maximum productivity of
0,9; 0,7 to 0,8 kg m-2 construction, equivalent to 18, 14 and 16 m2 sauces construction, the
quantity of 16.0 t ha-1. The application of spontaneous caatinga species yielded net profit of
R $ 6.070,00, return rate of R$ 2,80 and the profit margin of 64,2% for jitirana. Net profit
of R $ 2.920,00, rate of return of 1.86 and profitability index of 46,3% for the silk-flower
and net profit of R$ 4.270,00, rate of return of 2,26 and profitability index of 55,8%.
Accordingly, the cultivation of coriander fertilized with wild species of the caatinga
constitutes alternatively as green manure.
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Rubulotta, Giuliana. "Catalytic Conversion of Biogenic Substrate into Valuable Building Blocks." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1250.
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L'objectif de ce projet de thèse a été d’étudier l’activité catalytique de catalyseurs commerciaux contenant de nanoparticules métalliques pour l'hydrogénation du limonène. La réaction a été réalisée en l'absence de solvants et dans des conditions douces c’est à dire à basse température (30°C) et sous faible pression d'hydrogène (3 bar), conduisant à une production stable du (+)-p-1-menthene. Dans notre étude, les nanoparticules métalliques actives (Pt, Pd et Ru) et les supports (carbone, silice et alumine) ont été systématiquement modifiés et testés dans des conditions de réaction modérées (température ambiante, 3 bar H2). Notre étude a révélé une activité et sélectivité importante du catalyseur hétérogène Pt/C pour la réduction du R-(+)-limonène en (+)-p-1-menthène qui est le produit partiellement hydrogéné. Le Pt/C ainsi que Pt/Al2O3 est l’un des systèmes les plus actifs parmi les catalyseurs actuellement disponibles dans le commerce. De plus, l'activité catalytique et la stabilité de Pt/C ont été maintenues au cours des essais de recyclage en réacteur fermé. Ce catalyseur a également été utilisé en réacteur à flux continu, donnant des résultats prometteurs. L'hydrogénation sélective de la liaison C=C terminale du limonène par rapport de la liaison interne a été rationalisée par des études cinétiques détaillées qui révèlent une vitesse 8 fois plus importante par la double liaison terminale. Cette première étude nous a permis de développer la synthèse de nouveaux catalyseurs hétérogènes contenant diverses nanoparticules métalliques (Pt, Ru, Pt3Sn et Ni). Ils ont été préparés à partir d'une approche colloïdale et ont été testés dans l'hydrogénation de limonène. Ces catalyseurs contiennent la même charge métallique et des tailles de particules similaires (environ 2 nm) dispersées de façon homogène sur des oxydes non structurés (silice et d'alumine), du carbone, ou incorporés à l'intérieur des murs ou à la surface des pores de matériaux mésostructurés siliciques (SBA-15). L’ensemble des catalyseurs de la série du Pt ont révélés une activité accrue lors de l'hydrogénation sélective du limonène en p-menthène puis en p-menthane avec une vitesse de réaction très élevé. Parmi tous ces catalyseurs, celui contenant des nanoparticules de Pt dans les murs de la silice a montré au bout de deux heures de réaction un TOF d'environ 2200 h-1 et un rendement maximal pour le p-menthène d'environ 85% après 10 heures de réaction. Ce même catalyseur a été testé dans un réacteur en flux continu et affiche après 6 heures un rendement en p-menthene stable de 80%. Aucun produit d'isomérisation n’a été détecté dans le mélange brut au cours de la réaction. En conclusion, nous pouvons dire que l'utilisation d'un catalyseur hétérogène commercial comme le Pt/C ou l’utilisation d’un catalyseur hétérogène métallique développé à partir d'une approche colloïdale, Pt@SBA-15{murs}, permet d'obtenir une conversion sélective du limonène en p-menthène en réacteur fermé ainsi également en réacteur à flux continu. Des informations sur la cinétique de cette réaction ont également pu être obtenues<br>The goal of this PhD project was in an early stage to study the activities of several commercial metal nanoparticles based catalysts for the mild hydrogenation of limonene. The hydrogenation of limonene has been performed in neat limonene and under mild conditions, e.g. low temperature (30°C) and low molecular hydrogen pressure (3 bar), aiming at a sustainable production route for (+)-p-1-menthene. In our study, the active metal nanoparticles (Pt, Pd and Ru) and supports (carbon, silica and alumina) were systematically varied and tested. It was found that the heterogeneous catalyst Pt/C alongside Pt/Al2O3 under mild reaction conditions (room temperature and 3 bar H2) was highly active and selective in the reduction of R-(+)-limonene to the partial hydrogenation product (+)-p-1-menthene. Moreover, the catalytic activity and stability of Pt/C were maintained during recycling tests under batch conditions and thus allowed the implementation of this catalytic system into continuous flow operation. The selective hydrogenation of terminal C=C bond over the internal one in limonene was rationalized by detailed kinetic studies which revealed an 8-fold difference in reaction rate between the two reactions. This previous study with commercial catalysts gave the possibility to tune the synthesis of heterogeneous metal-based catalysts for the next step of the study, where different heterogeneous metal based catalysts (Pt, Ru, Pt3Sn, and Ni), developed from a colloidal-based approach were tested in the hydrogenation of limonene. Those catalysts contain the same metal loading and similar particle sizes (ca. 2 nm) homogeneously dispersed onto non structured oxides (silica and alumina), carbon, or embedded into the walls or at the pore surface of a mesostructured silica materials (SBA-15). All the catalysts from the Pt series were particularly active in the selective hydrogenation of limonene towards p-menthene with further conversion into p-menthane, showing a very high reaction rate. Among of all those catalysts, the one containing Pt nanoparticles embedded in the walls of the silica showed the highest TOF, of ca. 2200 h-1 after two hours of reaction and a maximum yield in p-menthene of ca. 85 % was obtained after 10 hours of reaction. The same catalyst was tested in a continuous flow system and a stable yield of ca. 80% during 6 hours of reaction was reached. No products of isomerization were detected in the crude mixture during the reaction. We could therefore conclude that, using either a heterogeneous commercial catalyst like Pt/C or using a heterogeneous metal based catalyst developed from a colloidal-based approach like SBA-15{walls}, it was possible to achieve a selective conversion of limonene into p-menthene in batch and in continuous flow conditions
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Prosa, Nicolo. "Synthèse supportée d'hétérocycles en milieux éco-compatibles : étude des conditions par lots et en flux continu. Purification par ultrafiltration en phase aqueuse." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00664999.
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Dans le but de réduire l'utilisation des solvants organiques dans les réactions et dans la purification, nous avons envisagé de coupler la synthèse supportée sur PEGs dans l'eau aux microréacteurs en flux continu et à l'ultrafiltration comme technique de purification. Dans un premier temps nous avons synthétisé des 3,4-dihydropyrimidin-2-ones (DHPMs) en utilisant comme étape clef la réaction multicomposant de Biginelli avec un aldéhyde supporté sur PEG. Dans ce but, nous avons trouvé que la liaison du PEG au 4-carboxybenzaldehyde, décrite dans le CH2Cl2, a lieu dans le PEG fondu (70 °C) en absence de solvant. La synthèse des DMPMs a ensuite été réalisée dans l'eau et dans le PEG fondu, à partir de l'aldéhyde supporté, et les produits finaux ont été isolés après saponification. Cette synthèse a ensuite été optimisée en microréacteurs en flux continu dans l'eau et la purification des adduits supportés a été réalisée par ultrafiltration dans l'eau.La stratégie décrite ci-dessus a été appliquée à des synthèses multi-étapes, la réaction de Baylis-Hillmann étant l'étape clef pour la préparation de tétrahydro-1,3-oxazine, tétrazoles, 1,4-oxazepin-3-ones et tétrahydro-1,3-pyrimidin-4-ones, composés dotés d'une activité biologique potentielle. Les synthèses de tétrahydro-1,3-oxazines et d'un tétrazole ont d'abord été optimisées par lots avec les purifications réalisées par ultrafiltration dans l'eau, puis adaptées en microréacteurs en flux continu.Tous les adduits supportés sur PEG ont été caractérisés par RMN et MALDI-Tof, et des nouvelles méthodes d'analyse RMN ont été mises au point afin de réduire l'intensité des signaux dus au PEG et de faciliter l'étude des molécules supportées.En conclusion nous avons développé la synthèse supportée, en milieux éco-compatibles de DHPMs, tétrahydro-1,3-oxazines et d'un tétrazole, par lots et en microréacteurs en flux continu, en utilisant les réactions de Biginelli et Baylis-Hillmann comme étapes clefs. Toutes les purifications ont été réalisées par ultrafiltration dans l'eau, afin de réduire l'utilisation de solvants organiques.
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Vieira, Flaviana de Andrade. "Doses de máxima eficiência física e econômica de flor-de-seda no rendimento de caupi-hortaliça." Universidade Federal Rural do Semi-Árido, 2014. http://bdtd.ufersa.edu.br:80/tede/handle/tede/89.
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Previous issue date: 2014-09-25<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Cowpea-vegetable (Vigna unguiculata (L.) Walp) is a grain legume, used in the human food, largely grown in semi-arid areas of the Brazilian Northeast. Green manure is an economical form and alternative for the low-income farmers to fertilize their crops. However, there is no information about the use of this green manure using roostertree. In view of this, this study aimed to determine the dose of agroeconomic efficiency maximum of roostertree in the green grain yield of cowpea-vegetable and its production components in function of different amounts of roostertree incorporated into the soil in sole crop. The experiment was conducted at the Experimental Farm Rafael Fernandes, from August to November 2013. The experimental design was a randomized complete block design with 5 replications. The treatments consisted of the following amounts of roostertree biomass incorporated into the soil: 20, 35, 50 and 65 t ha-1 on a dry basis. Each experimental plot had a total area of 3.6 m2 (3.00 m x 1.20 m), with a harvest area of 2.00 m2, containing 40 plants of cowpea-vegetable spaced of 0.50 m between rows with 10 plants per linear meter. The cultivar of cowpea-vegetable planted was BRS Itaim. It was incorporated 30% of the roostertree on August 22, 2013 in all plots, 20 days before planting. During the time of decomposition were performed daily irrigations in two shifts, one in the morning and one in the evening. After 20 days of sowing was made the incorporation of the 70% remaining of the material between the lines of the plots. The characteristics evaluated were: number of green pods per square meter, number of green grains per pod, yield of green pods, weight of 100 green grains and dry mass of grains and green pods. The economic indicators determined were: gross income (GI), net income (NI), production cost (PC), rate of return (RR) and profit margin (PM). The doses for maximum agronomic and economic efficiency of cowpea-vegetable were obtained with the incorporation into the soil of the quantities of roostertree of 59.4 and 54 t ha-1, respectively, with the yield of green grains of 3.25 t ha-1 and net income of R $ 9,624.74<br>O caupi-hortaliça (Vigna unguiculata (L.) Walp), é uma leguminosa granífera, utilizada na alimentação humana, bastante cultivada nas áreas semi-áridas do Nordeste brasileiro. A adubação verde é uma forma econômica e alternativa dos produtores rurais de baixa renda para fertilizar suas plantações. Contudo, não há informações sobre o uso dessa adubação verde utilizando flor-de-seda. Diante disto, este trabalho teve como objetivo determinar a dose de máxima eficiência agroeconômica de flor-de-seda na produtividade de grãos verdes de caupi-hortaliça e de seus componentes de produção em função de diferentes quantidades de flor-de-seda incorporadas ao solo em cultivo solteiro. O experimento foi conduzido na Fazenda Experimental Rafael Fernandes, no período de agosto a novembro de 2013. O delineamento experimental utilizado foi em blocos completos casualizados com 5 repetições. Os tratamentos consistiram das seguintes quantidades de biomassa de flor-de-seda incorporadas ao solo: 20, 35, 50 e 65 t ha-1 em base seca. Cada parcela experimental teve uma área total de 3,6 m2 (3,00 m x 1,20 m), com uma área útil de 2,00 m2 contendo 40 plantas de caupi-hortaliça no espaçamento 0,50 m entre fileiras com 10 plantas por metro linear. A cultivar de caupi-hortaliça plantada foi a BRS Itaim. Foram incorporadas 30% da flor-de-seda no dia 22 de agosto de 2013 em todas as parcelas, 20 dias antes do plantio. Durante o tempo de decomposição foram realizadas irrigações diárias em dois turnos, uma pela manhã e a outra pela tarde. Após 20 dias da semeadura foi feita a incorporação dos 70% restante do material nas entre linhas das parcelas. As características avaliadas foram: número de vagens verdes por metro quadrado, número de grãos verdes por vagem, produtividade de vagens verdes, peso de 100 grãos verdes e massa seca de grãos e de vagens verdes. Os Indicadores econômicos determinados foram: renda bruta (RB), renda líquida (RL), custo de produção (CT), taxa de retorno (TR) e índice de lucratividade (IL). As doses de máxima eficiência agronômica e econômica de caupi-hortaliça foram obtidas com a incorporação ao solo das quantidades de flor-de-seda de 59,4 e 54 t ha-1, respectivamente, com a produtividade de grãos verdes de 3,25 t ha-1 e renda líquida de R$ 9.624,74
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Flack, Kyle M. "Two approaches to green chemistry in industrially driven processes: aluminum tert-butoxide as a rate enhancing Meerwein-Ponndorf-Verley reduction catalyst applied to the technological transfer from batch to continuous flow and structural modifications of functionalized trialkylsilylamines as energy efficient carbon dioxide capture solvents." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44802.
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Green chemistry principles have been applied to the enhancement of two industrial chemistry problems. An industrially used reaction to form alcohols from aldehydes and ketones, the Meerwein-Ponndorf-Verley reduction, was improved by introducing a new catalyst Al(OtBu)₃. Due to the lower state of aggregation of this catalyst versus the conventional Al(OiPr)₃ catalyst, reduction rates were found to be faster in both pure iPrOH and mixed solvent systems for three model compounds: benzaldehyde, acetophenone, and a complex, chiral ketone, (S)-CMK. This allowed for the successful implementation of two important milestones; lowering the amount of catalyst needed necessary to complete the reactions (an economic benefit and lower waste) and the conversion from traditional batch reactions to continuous flow (a processing benefit) whereby reactions can be scaled-out rather than scaled-up. Another industrially important field of research that was focused on was CO₂ capture. High energy demands from current CO₂ capture methods such as aqueous amine solvents, specifically from coal-fired power plant flue gas, led to the development of non-aqueous reversible ionic liquids based on silylated amines. Structural modifications of the substitution around the silicon atom, the length of the alkyl chain bonding the silicon and amine, branching along the alkyl backbone, and investigating secondary and primary amines within this class of silylated amines were completed. These amines were reacted with CO₂ and the CO₂ capacity, the ionic liquid viscosity, reversal temperature and reaction enthalpy were all considered as a function of structure. In all cases the capacity was found to be not only greater than that of monethanolamine, an industrial standard, but higher than theoretical predictions through the formation of carbamic acid. Viscosity, reversal temperature, and reaction enthalpy were all found to be tunable through structure. These modifications gave significant insight into the necessary direction for optimization of these solvents as energy-efficient replacements of current CO₂ capture technology.
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Moraes, Edilson Carvalho de. "Viabilidade do consórcio de beterraba e caupi-hortaliça sob adubação com flor-de-seda e arranjos espaciais." Universidade Federal Rural do Semi-Árido, 2016. http://bdtd.ufersa.edu.br:80/tede/handle/tede/785.
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Previous issue date: 2016-12-12<br>The present work was conducted from August to November of 2014 at the 'Rafael Fernandes' Experimental Farm of the Federal Rural Semi-Arid University (FRSAU), with the objective of evaluating the viability of beet and vegetable-cowpea intercropping under fertilization with roostertree biomass and spatial arrangements of component cultures. The experimental design was a randomized complete block with four replications and the treatments arranged in a 4 x 3 factorial scheme, resulting from the combination of four quantities of roostertree biomass incorporated in the soil (20, 35, 50 and 65 t ha-1 on a dry basis) and three spatial arrangements between component cultures (2: 2, 3: 3 and 4: 4). The agronomic characteristics evaluated in the beet were: total, commercial and classified productivities of roots (extra, extra A, extra AA, great and scrap roots). In the vegetable-cowpea were evaluated: number of green pods per area, yield and dry weight of green pods, number of green grains per pod, weight of 100 green grains, and yield of green and dry grains. The agronomic and economic efficiency of the intercropping systems studied was evaluated through the indices of land equivalent ratio and productive efficiency, canonical variable score, gross and net returns, rate of return and net profit margin. There was no significant interaction between amounts of roostertree biomass incorporated into the soil and spatial arrangements for any characteristic evaluated in the beet, cowpea and the indices. The highest agronomic efficiency was obtained in the amount of 65 t ha-1 of roostertree biomass, while the highest economic efficiency was obtained in the amount of 28 t ha-1 of this manure. In absolute terms, the 2: 2 spatial arrangement provided the highest agroeconomic efficiency of the intercropped systems<br>O presente trabalho foi conduzido de agosto a novembro de 2014 na Fazenda Experimental "Rafael Fernandes" da Universidade Federal do Semi-Árido Rural (UFERSA), com o objetivo de avaliar a viabilidade do cultivo consorciado de beterraba e caupi-hortaliça sob adubação com biomassa de flor-de-seda e arranjos espaciais das culturas componentes. O delineamento experimental utilizado foi o de blocos casualizados com quatro repetições e os tratamentos arranjados em esquema fatorial 4 x 3, resultantes da combinação de quatro quantidades de biomassa de flor-de-seda incorporadas ao solo (20, 35, 50 e 65 t ha-1 em base seca) e três arranjos espaciais entre as culturas componentes (2:2, 3:3 e 4:4). As características agronômicas avaliadas na beterraba foram: produtividade total, comercial e classificada de raízes (em extra, extra A, extra AA, grandes e sucatas). No caupi-hortaliça foram avaliados, número de vagens verdes por área, rendimento e peso seco de vagens verdes, número de grãos verdes por vagem, peso de 100 grãos verdes e rendimento de grãos verdes e secos. A eficiência agronômica e econômica dos sistemas de consórcio estudados foi avaliada através dos índices de uso eficiente da terra e de eficiência produtiva, da pontuação da variável canônica, dos retornos bruto e líquido, da taxa de retorno e do indice de lucratividade. Não houve interação significativa entre as quantidades de biomassa de flor-de-seda incorporadas ao solo e os arranjos espaciais para qualquer característica avaliada na beterraba, caupi-hortaliça e nos índices agro-econômicos. A maior eficiência agronômica foi obtida na quantidade de 65 t ha-1 de biomassa de flor-de-seda, enquanto a maior eficiência econômica foi obtida na quantidade de 28 t ha-1 desse adubo. Em termos absolutos, o arranjo espacial 2: 2 proporcionou a maior eficiência agro-econômica dos sistemas consorciados<br>2017-08-16
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Rossi, Silmara. "Análise da atividade de leucócitos e de bifenilas policloradas aplicada ao estudo da fibropapilomatose em Chelonia mydas (Testudines, Cheloniidae) (Linnaeus 1758)." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-30042014-102858/.
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A tartaruga verde (Chelonia mydas) é uma tartaruga marinha que se alimenta e nidifica em locais da costa brasileira, ilhas e atóis. Esta espécie tem sido acometida pela fibropapilomatose (FP), doença considerada como uma das mais importantes ameaças à sua sobrevivência e caracterizada por tumores cutâneos benignos. A etiologia é multifatorial e complexa, possivelmente havendo relação entre Chelonid Fibropapilloma-associated Herpesvirus, fatores ambientais e genéticos. Foram estudadas 133 tartarugas verdes com e sem tumores provenientes de cinco áreas brasileiras: Florianópolis/SC, Ubatuba/SP, Vitória/ES, Almofala/CE e Fernando de Noronha/PE. Foram obtidos dados de biometria (comprimento curvilíneo da carapaça-CCC, massa corporal-MC e índice de condição corporal-ICC), tamanho (classificado por categorias A, B, C e D), quantidade e localização anatômica dos tumores, além da colheita de amostra sanguínea. Os objetivos foram (1) avaliar a atividade dos leucócitos por citometria de fluxo (fagocitose e burst oxidativo); (2) investigar a presença de sete congêneres de bifenilas policloradas (PCBs) e (3) estabelecer correlações entre PCBs e a atividade dos leucócitos. Houve diferenças no CCC entre tartarugas sem tumores de acordo com a área de estudo, na MC e no ICC entre animais acometidos ou não capturados em Ubatuba. Foram quantificados e classificados 1033 tumores de 50 tartarugas verdes, sendo que a quantidade por tartaruga variou de 1 a 61 e a maior parte foi classificada nas categorias de tamanho A (446 tumores) e B (520 tumores) e na região anterior (669 tumores). Foi observada diferença significativa nas concentrações do congênere PCB 138 entre tartarugas com e sem FP capturadas em Vitória. Animais acometidos tiveram maiores concentrações de todas as PCBs quantificadas, exceto as tartarugas verdes capturadas em Vitória no caso dos congêneres PCBs 118, 138, 153 e 180. PCB 138 foi quantificado em maior concentração nas amostras e PCB 180 em níveis menores. Não foram observadas correlações significativas entre concentrações de PCBs e atividade celular. A FP tem sido amplamente pesquisada e os estudos que visam estabelecer correlações entre poluentes químicos e saúde animal são extremamente importantes, pois podem contribuir para novas direções nos planos de ação para conservação.<br>The green sea turtle (Chelonia mydas) feeds and nests in Brazilian coast, islands and atolls. This species has been affected by fibropapillomatosis (FP), disease considered one of the most important threats to its survival and characterized by benign skin tumors. The etiology is multifactorial and complex, possibly having relation between Chelonid Fibropapilloma-associated Herpesvirus, environmental and genetic factors. Were studied 133 green sea turtles with and without FP from five Brazilian areas: Florianópolis/SC, Ubatuba/SP, Vitória/ES, Almofala/CE and Fernando de Noronha/PE. Were taken biometric data (curved carapace length-CCL, body mass-BM and body condition index-BCI), as well as size (classified by categories A, B, C and D), numbers and anatomical distribution of tumors, besides blood sample collection. The aims were (1) to assess leukocytes activity by flow cytometry (phagocytosis and oxidative burst); (2) to investigate the presence of seven congeners of polychlorinated biphenyls (PCBs) and (3) to establish correlations between PCBs and leukocytes activity. There were differences in CCL between turtles without FP according to the study area, in BM and BCI between affected and non-affected animals caught in Ubatuba. Were quantified and classified 1033 tumors of 50 green sea turtles, the number of tumors ranged from 1 to 61 and the most part of them was classified in categories of size A (446 tumors) and B (520 tumors) and in anterior region (669 tumors). Was observed difference in PCB 138 concentrations between green sea turtle with and without FP caught in Vitória. Affected animals had higher concentrations of all PCBs quantified, except green sea turtles caught in Vitória in the event of PCBs 118, 138, 153 and 180. Were quantified highest concentrations of PCB 138 and lowest of PCB 180. There were not significant correlations between PCBs concentration and leukocyte activity. The FP has been widely investigate and the studies that aimed to establish correlations between pollutants and animal health are very important, because can contribute for new directions in sea turtle conservation issues.
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Semedo, Ivandra Andrêa Lopes. "As práticas de análise de projectos e os determinantes do investimento em Cabo Verde." Master's thesis, Universidade de Évora, 2004. http://hdl.handle.net/10174/14780.
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Os estudos dos métodos de avaliação de projectos de investimento tiveram o seu início durante os anos 60 nos Estados Unidos. A evolução nesta área tem sido crescente, cada vez mais são utilizados pelas empresas métodos mais sofisticados, que actualizam os fluxos de caixa. Contudo, persiste ainda a preocupação de resolver a discrepância entre a teoria e a prática, pois os critérios apresentados teoricamente como sendo os mais adequados, como a TIR e o VAL, nem sempre são os mais usados pelas empresas. Da interpretação e análise de diversos trabalhos de investigações elaborados nesta área, em países como EUA, Reino Unido, Canada, entre outros, surge o interesse de efectuar uma pesquisa com abordagem diferente, recaindo sobre as maiores empresas de um pequeno país como Cabo Verde. Para a realidade de Cabo Verde não são conhecidos trabalhos de investigação nesta área. O objectivo deste projecto de investigação é conhecer o processo de investimento e os vários critérios utilizados na tomada de decisão, assim como o estudo das variáveis e factores que influenciam a decisão de investimento em Cabo Verde. 1 Para elaboração deste estudo foram enviados questionários a uma amostra de 126 empresas de Cabo Verde, tendo-se obtido um total de 51 respostas válidas, equivalendo a uma taxa de resposta de 40,47%. A metodologia incluí a análise dos questionários através da determinação de estatísticas descritivas e da estimação do modelo de regressão logistic. As empresas na sua generalidade, consideram o investimento realizado de acordo com as necessidades das mesmas e concordam em afirmar que os determinantes mais favoráveis ao investimento são as condições do mercado e de financiamento, exceptuando as perspectivas em relação às exportações que ficaram classificadas como sendo o factor mais desfavorável ao investimento. Os critérios ditos sofisticados são os mais utilizados em Cabo Verde. O Rácio Custo Beneficio (RCB) é o principal critério de análise, enquanto que a Taxa Interna de Rendibilidade (TIR) é o mais usado como critério auxiliar. O Período de Recuperação (PR) também tem uma grande expressividade como critério secundário. Os critérios não financeiros são importantes no processo de avaliação. A análise multivariada sugere que a decisão de avaliar ou não antes da sua implementação é explicada por diversas variáveis, como por exemplo o volume do negócio, a dimensão da empresa, o nível de investimento, entre outras.
/*** Abstract - The studies of the evaluation methods of investment projects started during the 60's in the United States of America. The evolution in this area has been increasing; enterprises are using more and more sophisticated methods that update their cash flow. However there is still the need to solve the difference between the theory and practice, for the criterions presented theoretically as the most appropriate, such as IRR and NPV, are not always the most used by enterprises. From the interpretation an analysis of the various investigation works elaborated in this area, in countries such as United States of America, United Kingdom and Canada, among others, comes the need of a research with a new approach about the biggest enterprises of a small country as Cape Verde. When it comes to Cape Verde realty there are no knowledge of investigations in this area. This investigation project intends to understand the investments process and the various criterions used in the decisions taken, and also to know the variables and factors of influence. To make this research possible questionnaires were sent to a sample of 126 enterprises in Cape Verde, from this sample 51 valid responses were obtained performing 40,47% of the response rate. The methodology includes the analysis of the questionnaires trough descriptive statistics and the estimation of the logistic regression model. The results related to the descriptive analyses suggest that in general enterprises, consider the investment realized with their needs, and agreed in stating that more favorable, determinant of investment is the market and financial states, excepting the perspectives about the exports relation that was classified like a more unfavorable determinant of investment. The so-called sophisticated criterions are the most used in Cape Verde. The Cost/Benefit Ratio (CBR) is the primary criterion of analyses, while Internal Rate of of Retum (IRR) it's the most used as a support. The PayBack also has a major significance as a support criterion. The non-financial criterion is very important on the evaluation process. The multivariate analyses suggest that the decision of evaluation or non evaluation before the implementation is explained with several variables, as for example, the volume of the business, the enterprise dimension, the level of investment, and others.
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Rocha, Diogo Librandi da. "Desenvolvimento de procedimentos analíticos em fluxo com multicomutação e foto-oxidação em linha para determinação espectrofotométrica de espécies de interesse ambiental, alimentício e clínico." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-06082013-075926/.
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A mecanização do preparo de amostras minimiza erros sistemáticos, a geração de efluentes e o tempo de análise. Sistemas em fluxo com microbombas solenoide (MPFS) atendem aos requisitos da mecanização de maneira robusta e versátil. Sendo assim, foram desenvolvidos procedimentos analíticos baseados em MPFS e foto-oxidação em linha visando ao fracionamento de fósforo em extratos de alimentos e águas naturais e à determinação de cloreto em águas naturais e urina. Fósforo é um nutriente importante cuja biodisponibilidade depende de sua forma química, tornando importante o fracionamento. O monitoramento de cloreto também é importante porque altas concentrações causam efeitos adversos ao meio ambiente e à saúde. Um MPFS foi proposto para o fracionamento de fósforo solúvel em extratos de alimentos, empregando foto-oxidação em linha do fósforo orgânico a ortofosfato, que foi quantificado pelo método do azul de molibdênio. Foi obtida resposta linear entre 5,0 e 40 mg L-1 para fósforo inorgânico (PI) e orgânico (PO), com limites de detecção de 0,5 e 1,2 mg L-1, respectivamente. Coeficientes de variação foram estimados em 1,2 e 3,6% para PI e PO, respectivamente, com frequência de amostragem de 80 determinações por hora. Por determinação, foram consumidos 380 µg de (NH4)6Mo7O24, 620 µg de ácido ascórbico e 790 µg de K2S2O8, gerando 2,5 mL de efluentes. Os resultados do fracionamento em extratos de alimentos concordaram com os obtidos pelo procedimento de referência (95% de confiança), baseado na digestão nitro-perclórica para a determinação de PO. Um procedimento com MPFS e espectrofotometria de longo caminho óptico foi desenvolvido para o fracionamento de fósforo (inorgânico e orgânico dissolvidos) em águas naturais. A quantificação foi baseada no método do azul de molibdênio, após fotoconversão das espécies a ortofosfato. Resposta linear foi observada entre 10 e 75 µg L-1 P, com limite de detecção de 2,0 µg L-1. Foram obtidos coeficiente de variação de 1,8% e frequência de amostragem de 40 determinações por hora. Por determinação, foram consumidos 160 µg de (NH4)6Mo7O24, 10 µg de SnCl2, 640 de µg K2S2O8 e 10 mg de NaOH, gerando 4,0 mL de efluentes. Os coeficientes angulares das curvas obtidas com 4 tipos diferentes de espécies de PO indicaram conversão quantitativa e os resultados obtidos para amostras de águas de rios foram concordantes com os obtidos pelo procedimento descrito pela AOAC (95% de confiança). Um procedimento limpo foi também desenvolvido para a determinação de cloreto em águas naturais e urina, evitando o uso de reagentes tóxicos. O analito foi foto-oxidado a cloro, que foi determinado por espectrofotometria através da descoloração do alaranjado de metila. Resposta linear foi observada entre 2,0 e 20 mg L-1, com limite de detecção de 0,7 mg L-1. O coeficiente de variação foi estimado em 1,6%, com frequência de amostragem de 75 determinações por hora e consumo de 7,5 µg de corante por determinação. Espécies concomitantes usualmente presentes nas amostras não interferiram mesmo em excesso em relação às concentrações normalmente encontradas. Os resultados das análises das amostras concordaram com os obtidos pelo procedimento de referência (95% de confiança). Os procedimentos propostos são alternativas limpas e rápidas para o fracionamento de fósforo e determinação de cloreto.<br>Mechanization of sample preparation minimizes systematic errors, waste generation and analysis time. Flow-based systems with solenoid micropumps (MPFS) attain the requirements for mechanization in a versatile and robust way. Therefore, analytical procedures based on MPFS and on-line photo-oxidation were developed aiming phosphorus fractionation in foodstuff and river waters and chloride determination in natural waters and urine. Phosphorus is an important nutrient for plants and animals and its bioavailability depends on its chemical form, making fractionation studies important. Chloride monitoring is relevant because the concentration unbalance leads to environmental and health issues. A MPFS was proposed for the fractionation of water soluble phosphorus in foodstuff, incorporating on-line photo-oxidation of organic phosphorus to phosphate, which was quantified by the spectrophotometric molybdenum blue method. Linear response was observed from 5 to 40 mg L-1 for both inorganic (PI) and organic (PO) phosphorus, with detection limits of 0.5 and 1.2 mg L-1, respectively. Coefficients of variation (n = 20) were estimated as 1.2 and 3.6% for PI and PO, respectively, with a sampling rate of 80 determinations per hour. Per determination, 380 µg of (NH4)6Mo7O24, 620 µg of ascorbic acid and 790 µg of K2S2O8 were consumed, generating 2.5 mL of waste. The results for food extracts agreed with those obtained by the reference procedure (95% confidence level) based on nitro-percloric digestion for PO determination. A MPFS procedure with long pathlength spectrophotometry was developed for phosphorus fractionation (dissolved organic and inorganic) in natural waters. Quantification was also based on the formation of molybdenum blue, after on-line photo-convertion of the organic species to orthophosphate. The analytical response was linear within 10 and 75 µg L-1 with a detection limit of 2.0 µg L-1. Coefficient of variation of 1.8% and sampling rate of 40 determinations per hour were achieved. Per determination, 160 µg of (NH4)6Mo7O24, 10 µg of SnCl2, 640 µg of K2S2O8 and 10 mg of NaOH were consumed, generating 4.0 mL of waste. Slopes of analytical curves obtained for four different PO species agreed with those obtained for orthophosphate, indicating quantitative conversion and the results for five freshwater samples agreed with those obtained by the AOAC reference procedure at 95% confidence level. A green procedure for chloride determination in urine and natural waters was also developed, avoiding hazardous chemicals. The analyte was on-line photo-converted to chlorine which was spectrophotometrically detected by methyl orange discoloration. The analytical response was linear from 2.0 to 20 mg L-1 Cl with a detection limit of 0.7 mg L-1. The coefficient of variation was 1.6% with a sampling rate of 75 determinations per hour, consuming 7.5 µg of the dye per determination. Usual concomitant species did not cause significant interference even in excess in relation to their highest concentration expected in the samples. The results for urine and water samples agreed with those obtained by the reference procedures at the 95% confidence level. The proposed procedures are environmentally friendly and fast alternatives for phosphorus fractionation and chloride determination
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Oliveira, Kássya Jemima Borges de. "Desempenho agroeconômico do bicultivo de rúcula consorciada com beterraba em função de quantidades de flor-de-seda e arranjos espaciais." Universidade Federal Rural do Semi-Árido, 2014. http://bdtd.ufersa.edu.br:80/tede/handle/tede/76.
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Previous issue date: 2014-02-24<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The experiment was conducted at the Experimental Farm 'Rafael Fernandes' of the Universidade Federal Rural do Semi-Árido (UFERSA), located in the district of Alagoinha, from August 2012 to February 2013 with the objective of evaluating the agrieconomic performance of the beet and arugula intercropped as a function of roostertree amounts incorporated into the soil and spatial arrangements of the component crops. The experimental design was of randomized complete blocks with five replications, with the treatments arranged in a 4 x 3 factorial scheme. The treatments consisted of the combinations of four amounts of roostertree incorporated into the soil (10, 25, 40 and 55 t ha-1 of dry matter) and three spatial arrangements (2B:2A, 3B:3A and 4B:4A), corresponding rows of beet (B) alternated with rows of arugula (A). The characteristics evaluated in the beet were: plant height, number of leaves per plant, total and commercial productivity, productivity of classified roots, fresh and dry mass of shoot; in the arugula were: plant height, number of leaves per plant, dry mass of shoot and yield of green mass; in the diagnostic leaves of beet and arugula were evaluated the contents of N, P, K; in the soil were assessed the amounts of bacterial and fungal colonies present before and after planting, as well as, the nutrient contents: N, P, K, pH, CEC and soil organic matter before and after sowing. In the intercropping systems were evaluated the productive efficiency index, the canonical variable score, gross income, net income, rate of return and profit margin. The highest agrieconomic performance of the intercropping beet and arugula was obtained in the amount of 55 t ha-¹ of roostertree incorporated into the soil and in the spatial arrangement of 2B: 2A. The amount of fungi and bacteria of the soil increased with increasing amounts of roostertree added to the soil in the arrangement of 2B: 2A. The multivariate method compared to the univariate method applied to the productive efficiency index was quite effective in determining the best arrangement 2B: 2A of the bicropping of arugula intercropped with beet. It is economically viable for the farmer to use the roostertree as green manure in the beet production intercropped with arugula<br>O experimento foi conduzido na Fazenda Experimental Rafael Fernandes da Universidade Federal Rural do Semi-Árido (UFERSA), localizada no distrito de Alagoinha, no período de agosto de 2012 a fevereiro de 2013, com o objetivo de avaliar o desempenho agroeconômico da beterraba e rúcula consorciadas em função de quantidades de flor-de-seda incorporadas ao solo e arranjos espaciais das culturas componentes. O delineamento experimental usado foi de blocos completos casualizados com cinco repetições, com os tratamentos arranjados em esquema fatorial 4 x 3. Os tratamentos consistiram de quatro quantidades de flor-de-seda incorporadas ao solo (10; 25; 40 e 55 t ha-1 de matéria seca) e três arranjos espaciais (2B:2R, 3B:3R e 4B:4R), que corresponderam a fileiras de beterraba (B) alternadas com fileiras de rúcula (R). As características avaliadas na beterraba foram: altura de plantas, número de folhas por planta, produtividade total e comercial, produtividade classificada de raízes, massa fresca e seca da parte aérea. Já na rúcula foram: altura de plantas, número de folhas por planta, massa seca da parte aérea e rendimento de massa verde. Nas folhas diagnósticas de beterraba e rúcula foram avaliados os níveis de N, P, K. Por sua vez, no solo foram avaliadas as quantidades de colônias de bactérias e fungos presentes antes e após o plantio, bem como os teores nutrientes: N, P, K, pH, CTC e matéria orgânica do solo antes e depois do plantio. Índices de eficiência agronômica e econômica de sistemas consorciados, tais como: índice de eficiência produtiva, escore da variável canônica, renda bruta, renda líquida, taxa de retorno e índice de lucratividade também foram avaliados. O maior desempenho agroeconômico para o consórcio de beterraba e rúcula foi obtido na quantidade de 55 t ha-¹ de flor-de-seda incorporada ao solo e no arranjo 2B:2R. A quantidade de fungos e bactérias do solo aumentou com as quantidades crescentes da flor-de-seda incorporadas ao solo no arranjo 2B:2R. O método multivariado quando comparado com o univariado aplicado ao índice de eficiência produtiva foi bastante eficaz na determinação do melhor arranjo 2B:2R do bicultivo de rúcula com beterraba. Nas condições do experimento, é economicamente viável para o agricultor o uso da flor-de-seda como adubo verde na produção beterraba consorciada com rúcula
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Oliveira, Lenilton Alex de Araújo. "Bicultivo de rúcula e alface em policultivo com cenoura sob quantidades de flor-de-seda e proporções de densidades populacionais." Universidade Federal Rural do Semi-Árido, 2014. http://bdtd.ufersa.edu.br:80/tede/handle/tede/169.
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Previous issue date: 2014-12-12<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>This work was conducted in the period from August to December 2012 at the Experimental Farm Rafael Fernandes of the Federal Rural University of Semi-Arid, Mossoró - RN, with the aim of studying the agroeconomic viability of the bicropping of arugula and lettuce intercropped with carrot in function of different amounts of roostertree incorporated into the soil and the proportions of population densities among the component crops in the semiarid conditions of the State of Rio Grande do Norte. The experimental design was a randomized complete blocks with four replications with treatments arranged in a 4 x 4 factorial scheme. The first factor was composed of the amounts of roostertree incorporated into the soil (10.0, 25, 40 and 55 t ha-1 on a dry basis) and the second factor by the proportions of population densities of the components crops in the polyculture 50R-50C-50A%; 40R-50C-40A%; 30R-50C-30A% and 20R-50C-20A% of populations recommended in the sole crops (PRSC) of: 1.000.000 plants per hectare for arugula, 500.000 plants per hectare for carrot and 250.000 plants per hectare for lettuce. The characteristics evaluated in crops were: plant height, number of leaves per plant, diameter of the lettuce plants, dry and green mass of shoots, total and commercial productivity of the roots, root dry mass and classified productivity of carrot roots. The indices of agronomic/biological efficiency evaluated were: partial land equivalent ratios of crops and of the polyculture. Economic indicators of gross income, net income, rate of return, profit margin and modified monetary advantage and yield efficiency index for DEA were also evaluated. The major agronomic polyculture indexes were obtained when the system was fertilized with the amount of 55 t ha-1 roostertree biomass. The population proportion that resulted in these higher indices was the 50R-50C-50A (%) of the recommended in the sole crops. The economic index that provided better efficiency of polyculture was that obtained with the profit margin of 37.23% in the optimum dosage of 24.25 t ha-1 of roostertree added to the soil. The highest proportions of population densities had an important role in obtaining of these indices. The use of roostertree as green manure proved viable in the polyculture of arugula, carrot and lettuce<br>O presente trabalho foi realizado no período de agosto a dezembro de 2012, na Fazenda Experimental Rafael Fernandes da Universidade Federal Rural do Semi-Árido, Mossoró RN, com o objetivo de estudar a viabilidade agroeconômica do bicultivo de rúcula e alface consorciado com cenoura em policultivo em função de diferentes quantidades de flor-de-seda incorporadas ao solo e de proporções de densidades populacionais entre as culturas componentes nas condições do Semiárido. O delineamento experimental foi de blocos completos casualizados com quatro repetições, com os tratamentos arranjados em esquema fatorial 4 x 4. O primeiro fator foi constituído pelas quantidades de flor-de-seda incorporadas ao solo (10,0; 25; 40 e 55 t ha-1 em base seca) e o segundo fator pelas proporções de densidades populacionais das culturas componentes em policultivo (50R-50C-50A%; 40R-50C-40A%; 30R-50C-30A% e 20R-50C-20A% das populações recomendadas nos cultivos solteiros: de 1.000.000 por hectare de plantas de rúcula, 250.000 plantas por hectare de alface e 500.000 plantas por hectare de cenoura PRCS). As características avaliadas nas culturas foram: altura de plantas, número de folhas por planta, diâmetro de plantas de alface, massa seca e verde da parte aérea, produtividade de raízes total e comercial, massa seca de raízes e produtividade classificada de raízes de cenoura. Os índices de eficiência agronômico/biológicos avaliados foram: índice de uso eficiente da terra das culturas e do policultivo. Os indicadores econômicos avaliados foram: renda bruta, renda líquida, taxa de retorno, índice de lucratividade, vantagem monetária corrigida e o índice de eficiência produtiva. Os maiores índices agronômico/biológicos do policultivo foram obtidos quando o sistema foi adubado com a quantidade de 55 t ha-1 de flor-de-seda. A proporção de densidade populacional que proporcionou esses maiores índices foi a de 50R-50C-50A (%) das populações recomendadas no cultivo solteiro das culturas componentes. O índice econômico que rendeu a melhor eficiência do policultivo foi aquele obtido com o índice de lucratividade de 37,23 % na dose otimizada de 24,25 t ha-1 de flor-de-seda adicionada ao solo. As maiores proporções de densidades populacionais tiveram um papel importante na obtenção desse índice. O uso da flor-de-seda como adubo verde mostrou-se viável no policultivo de rúcula, cenoura e alface
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Kuzura, Jevgenija. "Veiklą pradedančių įmonių vertės modeliavimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140603_111541-28036.
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Magistro baigiamajame darbe išanalizuoti veiklą pradedančių įmonių vertės nustatymo ypatumai. Pirmojoje, konceptualiojoje, darbo dalyje teoriniu aspektu analizuojami įmonės vertinimo ypatumai. Pateikiama įmonės vertės samprata ir reikšmė, išskiriami įmonės vertę įtakojantys veiksniai, aptarti įmonės vertės vertinimo principai. Išnagrinėti, susisteminti ir palyginti įmonės vertės nustatymo metodai, apžvelgiami tokių metodų parinkimo ypatumai. Antrojoje darbo dalyje atskleista veiklą pradedančių įmonių vertės modeliavimo tyrimo metodika. Trečiojoje, empirinėje, darbo dalyje atliktas išsamus UAB „FlixAuto“ veiklos vertinimas remiantis mokumo (likvidumo), pelningumo bei veiklos efektyvumo ir turto apyvartumo rodiklių analize, atliktas įmonės bankroto prognozavimas. Remiantis diskontuotų pinigų srautų (DCF) metodu apskaičiuota UAB „FlixAuto“ vertė. Atliekama kiekybinio tyrimo analizė. Pateikiamos atskirų vertinimų išvados. Tyrimas baigiamas išvadomis ir pasiūlymais.<br>Master's thesis analyzed the value of start-ups setting features. The first, conceptual, theoretical part of the work outlined in the company's assessment features. Presented the concept of the company's value and importance of secreted factors influencing the value of the company, to discuss the company's value evaluation. To examine the structure and compare the company valuation methods, a review of such methods for selecting features. The second part of start-ups revealed the value of simulation methods. Third, empirical work in a detailed JSC „FlixAuto“ performance evaluation based on solvency (liquidity), profitability and operating efficiency and asset turnover ratio analysis performed bankruptcy prediction. Based on the discounted cash flow (DCF) method calculated JSC „FlixAuto“ value. Performed a quantitative analysis of the research. Given for individual findings. The study ends with conclusions and suggestions.
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ARNAUD, Edinaldo da Rocha. "Viabilidade agroeconômica da aplicação da flor-de-seda (calotropis procera) em diferentes quantidades e períodos de incorporação na cultura da beterraba." Universidade Federal de Campina Grande, 2014. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/834.
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Previous issue date: 2014<br>O uso de espécies espontâneas da caatinga representa uma opção de fertilização orgânica para os agricultores familiares que labutam na produção de hortaliças, sendo a florde-seda, espécie de grande ocorrência na região de estudo, além de ser encontrado em diversas localidades da região nordeste do país em condições edáficas diferentes. Um experimento foi conduzido na Fazenda Experimental Rafael Fernandes, localizada no distrito de Alagoinha, zona rural de Mossoró-RN, no período de outubro de 2010 a fevereiro de 2011, com o objetivo de avaliar a viabilidade agroeconômica da aplicação da flor-de-seda (Calotropis procera) na cultura da beterraba em cultivo solteiro. O delineamento experimental usado foi o de blocos completos casualizados com os tratamentos arranjados em esquema fatorial 5 x 4, com três repetições. Os tratamentos consistiram da combinação de quatro quantidades de flor-de-seda (0; 0,7; 1,4; 2,1 e 2,8 kg m-2 de canteiro em base seca), com quatro períodos de incorporação (0; 14; 28 e 42 dias antes do plantio). A cultivar de beterraba plantada foi a Early Wonder. As características avaliadas foram: altura de plantas, rendimentos de massa fresca e seca da parte aérea, produtividade comercial de raízes e produtividade de massa seca de raízes. Também foram utilizados alguns indicadores econômicos, tais como: renda bruta e custo de produção, renda líquida, taxa de retorno e índice de lucratividade, as quais foram utilizadas para verificar a viabilidade econômica. Não se observou interação entre os fatores estudados. O melhor desempenho produtivo da beterraba foi observado na quantidade 2,3 kg m-2 de canteiro de flor-de-seda incorporada ao solo, com valor médio de 2,44 kg m-2 de canteiro de beterraba, com rentabilidade de liquida de 4.040,00 R$, taxa de retorno da ordem de 2,65 R$ e índice de lucratividade de 62,3%. Em relação aos períodos de incorporação, 0 dia foi o que promoveu a maior produtividade comercial de beterraba com valor médio de 2,2 kg m-2 de canteiro de beterraba, com rentabilidade liquida de 3.500,00 R$, taxa de retorno da ordem de 2,43 R$ e índice de lucratividade de 58,9%. O cultivo da beterraba adubado com flor-de-seda constitui em uma alternativa viável para o produtor.<br>- The use of spontaneous species of the caatinga represents an option of organic
fertilizer for farmers who labor in the production of vegetables, been the silk flower, species
of large occurrence in the study area, and it is found in various locations the northeast region
of the country in different soil conditions. An experiment was conducted at the Experimental
Farm Rafael Fernandes, located in Alagoinha district, a rural area of Mossoró-RN, from
October 2010 to February 2011, in order to evaluate the agricultural economic viability of the
application of the silk flower (Calotropis procera) in beet cultivation in monocrop. The
experimental design was a randomized complete block with treatments arranged in a factorial
5 x 4 with three replications. The treatments were a combination of four amounts of silk
flower (0, 0.7, 1.4, 2.1 and 2.8 kg m-2 site on a dry basis), with four periods of incorporation
(0 , 14, 28 and 42 days before planting). The planted cultivar of beet was the Early Wonder.
The characteristics evaluated were: plant height, fresh weight yields and shoot dry,
commercial root yield and dry matter yield of roots. They were also used some economic
indicators such as gross income and cost of production, net income, rate of return and
profitability index, which were used to verify the economic viability. There was no interaction
between treatments. The best beet production performance was observed in the amount 2.3 kg
m-2 site of silk flower incorporated into the soil, with an average value of 2.44 kg m-2 beet
site, with net profitability 4040.00 £, rate of return of around £ 2.65 and 62.3% profitability
index. For periods of incorporation, 0 days was what promoted the highest commercial yields
of beet with a mean value of 2.2 kg m-2 beet site, with net profit of R $ 3,500.00, rate of
return order 2.43 R $ and 58.9% profitability index. The cultivation of beet fertilized with
silk-flower constitutes a viable alternative to the producer.
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Vincent, Marc. "Validation de la simulation de l’astigmatisme : application aux verres progressifs Effect of simulated and real spherical and astigmatism defocus on visual acuity and image quality score Subjective Evaluation of Defocus and Astigmatism Combinations Using Image Simulation in Presbyopes Method of assigning progressive addition lenses based on subjective image quality score." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP043.
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La vision à travers un verre progressif est un processus dynamique tout particulièrement en vision de près lors de la lecture. Le porteur est amené à regarder dans les parties latérales du verre. Or ces zones contiennent de l’astigmatisme qui peut être particulièrement gênant. Il existe différents types de verres progressifs qui se caractérisent par une répartition spécifique de l’astigmatisme en périphérie. L’objectif, à terme, serait de permettre une sélection du verre progressif en présentant au futur porteur des images simulées pour lesquelles il devrait donner des notes liées à la qualité de l’image perçue. A l’aide d’un calcul optique (i.e., convolution entre un objet et une fonction d’étalement du point), nous pouvons simuler l’apparence d’une image vue à travers une certaine optique. L’objectif de ce travail est donc de valider la possibilité de simuler la vision à travers un verre progressif et de faire le lien entre qualité de vision et choix du porteur. Dans un premier temps, nous avons comparé la qualité de vision à travers une optique adaptative simulant des défauts sphériques et cylindriques avec des images simulées rendant compte des mêmes défauts optiques. Une différence de qualité de vision entre 20 (i.e. flou sphérique) et 35% (i.e. flou astigmate) entre flou simulé et optique a été observée. Le flou simulé était toujours plus important que le flou optique. Néanmoins, ces différences demeuraient inférieures à la différence cliniquement significative. Dans un second temps, nous avons directement utilisé un verre progressif. Les défauts optiques testées étaient alors des combinaisons sphériques et cylindriques correspondants à des points précis du verre progressif le long de l’axe horizontal passant par le centre optique de vision de près. Nous avons considéré dans la simulation de nos images que le sujet pouvait plus ou moins accommoder. Nous avons observé que l'accommodation jouait un rôle lors de la comparaison entre le flou optique et le flou simulé. Les sujets presbytes semblent capables de produire un faible niveau d'accommodation qui contrebalance une partie de l'effet délétère de l'astigmatisme sur la qualité de l'image. Nous avons ensuite mis en place un dispositif plein champ d’analyse d’un verre progressif conduisant au choix d’un type de verres progressifs par différents porteurs. Parallèlement, nous avons mesuré la qualité de vision (i.e., notation d’images simulées et mesure d’acuité visuelle) le long de l’axe horizontal de vision de près de ces mêmes sujets. Les résultats de cette dernière étude ont montré que l’acuité visuelle n’est pas un bon test pour prédire la qualité de vision à travers des verres progressifs, le test n’a fonctionné que pour 65% des sujets. Au contraire, le test de notation d’images subjectives a permis de prédire le choix final du design pour 90% des sujets. Bien que les résultats statistiques obtenus pour les différentes conditions d’images simulées montrent une réelle différence entre la condition réelle et simulation, nous observons que les images simulées prenant en compte une part d’accommodation (i.e., changement de sphère dans la simulation) sont plus proches de la réalité. L’accommodation semble donc bien jouer un rôle important lorsqu’un astigmatisme est introduit. L’étude de l’accommodation en présence d’astigmatisme permettrait d’optimiser la simulation des images<br>Vision through a progressive addition lens is a dynamic process especially in near vision when reading. The wearer is led to look into the side parts of the lens. These areas contain astigmatism, which can be particularly annoying. There are different types of progressive addition lenses that are characterized by a specific distribution of astigmatism around the periphery. The objective, in the long term, would be to allow a selection of progressive addition lenses by presenting the future wearer with simulated images for which he or she would have to give notes related to the quality of the perceived image. Using an optical calculation (i.e., convolution between an object and a point spread function), we can simulate the appearance of an image seen through an optic. The objective of this work is therefore to validate the possibility of simulating vision through a progressive addition lens and to make the link between vision quality and wearer choice. In a first step, we compared the quality of vision through adaptive optics simulating spherical and cylindrical defocus with simulated images showing the same optical defects. A difference in vision quality between 20 (i.e. spherical blur) and 35% (i.e. astigmatic blur) between simulated and optical blur was observed. The simulated blur was always greater than the optical blur. These differences were less than the clinically significant difference. In a second step, we directly used a progressive addition lens. The optical defocus tested were then spherical and cylindrical combinations corresponding to specific points of the progressive addition lens along the horizontal axis passing through the near vision optical center. We considered in the simulation of our images that the subject could accommodate. We observed that accommodation played a role when comparing the optical blur with the simulated blur. Presbyopic subjects appear to be able to produce a low level of accommodation that offsets some of the deleterious effect of astigmatism on image quality. We then set up a full-field progressive addition lens analysis device leading to the choice of a type of progressive lens by different wearers. At the same time, we measured vision quality (i.e., simulated image scoring and visual acuity measurement) along the horizontal axis of near vision for these same subjects. The results of the latter study showed that visual acuity is not a good test for predicting vision quality through progressive lenses; the test only worked for 65% of the subjects. On the contrary, the subjective image scoring test predicted the final design choice for 90% of the subjects. Although the statistical results obtained for the different simulated image conditions show a real difference between the real and simulated conditions, we observe that simulated images taking into account some accommodation (i.e., change of sphere in the simulation) are closer to reality. Accommodation thus seems to play an important role when astigmatism is introduced. The study of accommodation in the presence of astigmatism would make it possible to optimize the simulation of the images
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Bruniaux, Sophie. "Nouveaux hydrotropes biosourcés : conception, synthèse et propriétés physico-chimiques en milieu hautement salin." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2378.
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Historiquement, l’industrie chimique est basée sur l’utilisation de ressources fossiles, mais depuis les années quatre-vingt-dix, des procédés alternatifs ont été développés afin d’être plus verts et de répondre aux questions environnementales concernant l’éco-responsabilité. Dans ce contexte, un travail collaboratif entre trois laboratoires académiques et la SAS PIVERT a émergé, afin de trouver de nouveaux hydrotropes biosourcés à partir de divers polyols, comme le glycérol par exemple qui est le sous-produit majoritaire lors de la production de biodiesel, avec une résistance aux hautes conditions salines. Un design particulier a été défini par notre partenaire physico-chimiste pour cette synthèse d’hydrotropes. Ainsi, pour obtenir ces composes, différentes approches ont été utilisées comme par exemple, une nouvelle méthode de méthylation utilisant du méthanol sub/supercritique avec une phase d’optimisation et d’exemplification de la réaction. Une autre méthode porte sur la transposition de l’alkylation réductrice de différents alcools utilisant des conditions de flux via l’utilisation du HCube Pro de chez ThalesNano, mais aussi d’une catalyse hétérogène pour l’obtention d’un panel large d’éthers<br>Historically, chemical industry was based on fossil ressources, but alternative processes have been developed since the nineteens to be green and to answer to the environmental eco-responsibility questions. In this context, a collaboration work between three public laboratories and the SAS PIVERT emerged to find new biosourced hydrotropes starting from various polyols – such as glycerol, main byproduct of the fuel production – and resistant to high saline conditions. A specific design was defined by our physico-chemical partner for the synthesis of hydrotropes. Differents approaches were used to obtain these compounds, such as a new method of methylation using sub/supercritical methanol with a phase of optimization, and another about the scope of the reaction that reduced the reaction steps. The transposition of the reductive alkylation of various alcohols was also realized – using a heterogeneous catalysis – with the obtention of various ethers, in continuous flow conditions, by the intermediate of the use of the HCube Pro from ThalesNano
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Yalgin, Hasret. "Vers la synthèse éco-compatible de dérivés de quinoléine biosourcés en flux continu." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2256.
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Les composés incorporant un motif quinoléine occupent une place privilégiée parmi les substances pharmaceutiques, et possèdent également une large variété d’applications dans des domaines comme la cosmétique ou l’agro-alimentaire. Cependant, malgré l’intérêt de ces dérivés hétérocycliques, les synthèses classiques de quinoléines décrites dans la littérature sont peu respectueuses de l’environnement. Pour pallier à ce problème, nous avons envisagé une approche éco-compatibles usant de matières premières bio-sourcées qui serait applicable à l’échelle industrielle. Plus particulièrement, ce projet présente deux enjeux majeurs : 1) effectuer la synthèse de dérivés de quinoléine à partir de matières premières issues de la biomasse tout en respectant les principes de la chimie vertes, et 2) adapter ce procédé en flux continu, en vue d’une potentielle application industrielle. Au cours de ce travail, nous rapportons notre étude sur la transposition de la réaction de Skraup en flux continu. En particulier, nous avons développé une synthèse de quinoléines en flux continu valorisant le glycérol – sous-produit principal de la réaction de transestérification des triglycérides – comme précurseur d’acroléine, et ayant lieu dans l’eau. Ces travaux de thèse permettent de franchir une étape vers la production éco-compatibles de composés hétérocycliques<br>The quinoline motif is present in numerous pharmaceutically relevant drugs as well as in a wide range of active ingredients used in cosmetic and food-processing industries. Despite its prevalence, typical quinoline synthesis reported in the literature are not scalable, and do not involve green protocols that take advantage of renewable resources. To address both limitations, we envisioned a green and industrially applicable approach using abundant resources. Specifically, we faced two main challenges: 1) to develop a sustainable synthesis of quinolines and 2) to apply this synthesis in a flow apparatus for potential industrial application. Throughout this dissertation, we disclose our studies toward the sustainable Skraup reaction. In particular, we developed a flow-synthesis of quinolines proceeding from glycerol - the main byproduct of biofuel production - as a building block and water as a green solvent. This innovative method marks a step toward the green production of heterocyclic compounds
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Fukuda, Daniel Akio. "Identificação da ligação direta de uma Fosfolipase D de Loxosceles gaucho às plaquetas." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-08022018-143046/.
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Fosfolipases D (FLD) do veneno das aranhas do gênero Loxosceles são capazes de causar entre outros efeitos, uma forte agregação plaquetária cujo mecanismo ainda não foi elucidado. Portanto, para estudar o papel das FLDs nesta atividade, uma FLD recombinante de L. gaucho (LgRec1) foi fusionada com a proteína fluorescente verde (EGFP) e utilizada como uma sonda para detectar a interação de LgRec1 com plaquetas. Essa quimera, denominada EGFP-LgRec1, manteve as principais características da LgRec1. A microscopia confocal das plaquetas mostrou que LgRec1 não requer componentes plasmáticos para se ligar às plaquetas, embora estes sejam necessários para que a LgRec1 induza agregação. Além disso, foi observado que a ação da LgRec1 leva à exposição de fosfatidilserina. Contudo, esta exposição não está relacionada à morte celular. Portanto, este trabalho mostrou que uma FLD de Loxosceles se liga a plaquetas, promovendo a exposição de fosfatidilserina, possibilitando a ligação de fatores de coagulação e resultando na agregação plaquetária.<br>Phospholipases D (PLD) from spider venom of the genus Loxosceles are capable of causing, among other effects, a strong aggregation of platelets and its mechanism has not yet been elucidated. Therefore, to study the role of PLDs in this activity, a recombinant L. gaucho PLD (LgRec1) was fused with a green fluorescent protein (EGFP) and used as a probe to detect the interaction of LgRec1 with platelets. This chimera, named EGFP-LgRec1, remained the main activities of LgRec1. Platelet confocal microscopy has shown that LgRec1 does not require plasma components to bind to platelets, although these are required for LgRec1 to induce aggregation. In addition, it has been observed that the action of LgRec1 leads to exposures of phosphatidylserine. However, this exposure is not related to cell death. Therefore, this work showed that a Loxosceles PLD binds to platelets, promoting an exposure of phosphatidylserine, that may act as a scaffold for coagulation factors, resulting in platelet aggregation.
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Gacem, Lakhdar. "Cristallogenèse et caractérisations du diphosphate Na2ZnP2O7 pur et dopé et de la solution solide de type pérovskite Na(1x)BaxNb(1x)TixO3." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00474354.
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Les propriétés physiques d'un matériau sont intimement liées à sa structure cristalline et dans le cas d'ions dopants aux sites qu'ils occupent. La première partie de ce travail est dédiée au matériau diphosphate de sodium et de zinc Na2ZnP2O7, cristallisé out vitreux et ceci pour les ions dopants Co2+, Ni2+, Mn2+ et Eu3+. Les phases cristallisées ont été obtenues par la méthode Czochralski, les verres par trempe à partir de l'état fondu. Un ensemble de caractéristiques physiques ont été mises en jeu (Raman, infrarouge, RPE, absorption optique, luminescence) pour déterminer les sites occupés par les ions dopants et l'influence sur les propriétés optiques. La deuxième partie de cet travail consiste à une meilleure connaissance des matériaux diélectriques sans plomb appartenant à la famille pérovskite et plus particulièrement à la solution solide NaNbO3-BaTiO3. Des monocistaux ont été obtenus par la méthode des flux et caractérisés en utilisant plusieurs techniques : diffraction X, microanalyse, évolution thermique des domaines ferroélectriques-ferroélastiques, mesures diélectriques, piézoélectriques et pyroélectriques.
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Pedro, Tânia Cristina Ferreira Ribas Vaz. "Development of solid phase extraction flow-based tools for environmental monitoring." Doctoral thesis, 2020. http://hdl.handle.net/10400.14/32160.
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The development of new analytical tools can be considered a non-stop challenge due to the constant search for new improved features and also to the emerging environmental contaminants. Flow-based methodologies stand out in contributing for this analytical challenge, providing the automation and miniaturization of the analysis including sample pre-treatment.
This thesis was developed based on two major objectives, one of them was to develop new miniaturized and automated analytical tools based on flow analysis for environmental monitoring. When designing new methodologies, another essential objective was to simplify sample preparation by coupling these techniques, based on solid phase extraction (SPE), within the developed flow-based system. The developed methodologies were optimized based on the same principles: minimize the use of reagent, make greener choices of the reagents, minimize the effluent production, lower the limits of detection and quantification, simplify and minimize sample/reagent handling. The use of the in-line SPE strategy showed to bring advantageous features to the analytical method (lowering limits of detection and quantification). The in-line SPE was achieved by using commercial resins (NTA and Chelex 100) and also a lab-made polymer inclusion membrane (Chapter 3).
A biparametric sequential injection system for the determination of copper and zinc in water and soil leachates was developed (Chapter 3). The strategy was to use a non-specific coulour reagent (4-(2-Pyridylazo)resorcinol – PAR) and explore the use of two different sorbent materials to selectively separate the two different metal ions in the same manifold. A polymer inclusion membrane (PIM) and the commercial resin Chelex 100 were the chosen materials to selectively retain zinc and copper, respectively. It was the first time that a PIM was used with this purpose in a flow system.
A spectrophotometric method for iron quantification using a newly designed chromogenic chelator was developed (Chapter 4). This low toxicity iron chelator was a specially designed 3-hydroxy-4-pyrydinone functionalized with ethers. Furthermore, this reagent demonstrated to display high affinity and specificity for iron ions. With the main objective of quantifying iron in a variety of water samples (fresh and marine water) a strategy including SPE was added to the manifold. By using an in-line SPE process, resorting to a NTA resin column coupled to the flow system, sample matrix clean-up and also the enrichment of the analyte was achieved.
A method for the screening of biogenic amines in waters was developed (Chapter 5). The system was divided in two analytical parts. The first one was devoted to the pre-concentration of the analyte using a column packed with Chelex 100; the second was the derivatization of the biogenic amines using fluorescamine for the fluorescent detection of the analyte. This method intended to be a suitable and ease to operate system to obtain real-time information about biogenic amines content in water.
A flow injection system for the spectrophotometric determination of the total zinc content in plant digests was developed (Chapter 6). By using a NTA resin column, zinc pre-concentration and the removal of possible interferences was accomplished. A specially designed multi-reflection flow cell coupled with a light emitting diode was the chosen detection system for the spectrophotometric determination of zinc using Zincon as colour reagent. The physical configuration of the flow cell contributed to improve the limit of detection and minimize refractive index gradients produced by the mixture of the reagents.<br>O desenvolvimento de novas ferramentas analíticas pode ser considerado um desafio constante, devendo-se tal à busca incessante de características analíticas cada vez melhores e também ao surgimento de novos contaminantes ambientais. Os métodos em fluxo destacam-se ao contribuir para este desafio analítico, nomeadamente na automatização e miniaturização da análise, incluindo o tratamento da amostra.
A tese foi desenvolvida com base em dois objetivos principais, um dos quais se centrou no desenvolvimento de novos métodos analíticos em fluxo para a monitorização ambiental. No planeamento de novos métodos teve-se em consideração outro grande objetivo, a simplificação do tratamento da amostra, associando para tal técnicas de extração em fase sólida ao sistema de fluxo desenvolvido. A otimização dos sistemas analíticos teve por base os mesmos conceitos: minimizar o consumo de reagentes; fazer uma escolha mais ecológica relativamente aos reagentes; minimizar a produção de efluentes, melhorar limites de deteção e quantificação; simplificar e minimizar o manuseamento de amostras/reagentes. Ao recorrer a processos de extração em fase sólida em linha, conseguiu-se uma melhoria das características analíticas associadas ao método (baixando o limite de deteção e quantificação). De uma forma geral, a extração em fase sólida em linha foi realizada recorrendo à utilização de resinas comerciais (NTA e Chelex 100), mas também foi utilizada uma membrana produzida em laboratório (Capítulo 3; membrana de inclusão de polímeros – PIM).
Foi desenvolvido um sistema biparamétrico por injeção sequencial para a determinação de cobre e zinco em águas e lixiviados de solos (Capítulo 3). A estratégia usada para o desenvolvimento deste método envolveu o uso de um reagente de desenvolvimento de cor não específico - (4-(2-piridilazo)resorcinol – PAR) - e o explorar da utilização de diferentes materiais adsorventes para separar seletivamente os dois iões metálicos no mesmo sistema. Para tal recorreu-se a uma membrana de inclusão de polímeros (PIM) e a uma resina comercial (Chelex 100) com o intuito de reter e separar o zinco e o cobre, respetivamente. De salientar que foi a primeira vez que uma PIM foi utilizada com este objetivo num sistema de fluxo.
No Capítulo 4 foi desenvolvido um método espectrofotométrico para a determinação de ferro em águas naturais utilizando um quelante cromogéneo desenvolvido recentemente. O quelante de ferro de toxicidade baixa pertence ao grupo das 3-hidroxi-4-piridinonas funcionalizado com éteres. Este reagente demonstrou ainda ter uma elevada afinidade e especificidade para o ferro. Com o objetivo de aplicar o método à determinação de ferro em diferentes tipos de águas naturais (doces e salinas), foi incluído no sistema de fluxo um passo adicional de extração em fase sólida. Para tal, utilizou-se uma coluna empacotada com resina de NTA, a qual permitiu realizar a limpeza da matriz da amostra e também a possibilidade de se concentrar o analito de interesse.
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Foi desenvolvido um método para o despiste de aminas biogénicas em águas (Capítulo 5). O sistema foi dividido em duas fases fundamentais. A primeira fase consistiu na pré-concentração do analito recorrendo a uma coluna empacotada com Chelex 100 acoplada ao sistema de fluxo; de seguida procedeu-se à derivatização das aminas com fluorescamina para a sua deteção fluorimétrica. O método desenvolvido tinha como principal objetivo ser de fácil execução, mas que desse uma resposta em tempo real sobre o conteúdo em aminas biogénicas em águas.
Foi desenvolvido um sistema por injeção em fluxo para a determinação de zinco total em plantas (Capítulo 6). Com a implementação de uma coluna de NTA no sistema de fluxo conseguiu-se a pré-concentração de zinco e também a remoção de possíveis interferentes presentes na amostra. Como sistema de deteção foi utilizada uma célula de fluxo multi-reflexão acoplada a um LED, visando a determinação espectrofotométrica do zinco utilizando Zincon como reagente de desenvolvimento de cor. Devido à configuração física da célula de fluxo, esta contribuiu para a minimização da influência da refração produzida pela mistura dos reagentes e para o melhoramento do limite de deteção do método.
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"How Will Hydrologic Change Alter Riparian Plant Communities of the Arid and Semi-Arid Southwest? The Problem Approached from Two Perspectives." Master's thesis, 2011. http://hdl.handle.net/2286/R.I.14303.
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abstract: Climate change has the potential to affect vegetation via changes in temperature and precipitation. In the semi-arid southwestern United States, heightened temperatures will likely lead to accelerated groundwater pumping to meet human needs, and altered storm patterns may lead to changes in flood regimes. All of these hydrologic changes have the potential to alter riparian vegetation. This research, consisting of two papers, examines relationships between hydrology and riparian vegetation along the Verde River in central Arizona, from applied and theoretical perspectives. One paper investigates how dominance of tree and shrub species and cover of certain functional groups change along hydrologic gradients. The other paper uses the Verde River flora along with that river's flood and moisture gradients to answer the question of whether functional groups can be defined universally. Drying of the Verde River would lead to a shift from cottonwood-willow streamside forest to more drought adapted desert willow or saltcedar, a decline in streamside marsh species, and decreased species richness. Effects drying will have on one dominant forest tree, velvet ash, is unclear. Increase in the frequency of large floods would potentially increase forest density and decrease average tree age and diameter. Correlations between functional traits of Verde River plants and hydrologic gradients are consistent with "leaf economics," or the axis of resource capture, use, and release, as the primary strategic trade-off for plants. This corresponds to the competitor-stress tolerator gradient in Grime's life history strategy theory. Plant height was also a strong indicator of hydrologic condition, though it is not clear from the literature if plant height is independent enough of leaf characteristics on a global scale to be considered a second axis. Though the ecohydrologic relationships are approached from different perspectives, the results of the two papers are consistent if interpreted together. The species that are currently dominant in the near-channel Verde River floodplain are tall, broad-leaf trees, and the species that are predicted to become more dominant in the case of the river drying are shorter trees or shrubs with smaller leaves. These results have implications for river and water management, as well as theoretical ecology.<br>Dissertation/Thesis<br>M.S. Plant Biology 2011
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Carneiro, Clarisse Isabel Teixeira. "Sustainable urban drainage: Green roofs." Master's thesis, 2015. http://hdl.handle.net/10316/38682.
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Dissertação de Mestrado Integrado em Engenharia do Ambiente apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.<br>As recentes inundações em todo o mundo mostram a vulnerabilidade dos ambientes urbanos às condições hidrológicas extremas. O aumento da urbanização, sem o devido planeamento, combinado com as alterações climáticas levam ao aumento dos caudais superficiais provocando, assim, recorrentes inundações. Reconstruir o sistema de drenagem para fazer face a este problema pode não ser eficiente ou viável, quer tecnicamente quer economicamente. Técnicas inovadoras como a dos telhados verdes, construção de pavimentos permeáveis, canais abertos com vegetação, bacias de retenção, entre outros, atenuam os picos de cheia, diminuindo o risco de cheia, e reduzem a concentração de poluentes das águas de chuva nas áreas urbanas.
Neste estudo é analisado o potencial dos telhados verdes na redução do pico de cheia e da quantidade de caudal superficial, bem como a sustentabilidade desta tecnologia, economicamente, socialmente e ambientalmente. A análise da redução do pico de cheia e da quantidade de caudal superficial foi efetuada considerando a aplicação desta tecnologia na área do Pólo II da Universidade de Coimbra, recorrendo ao programa de modelação hidráulica-hidrológica Storm Water Management Model (SWMM), da Environmental Protection Agency (EPA) dos Estados Unidos da América (EUA).
Os resultados obtidos indicam uma redução do pico de cheia entre os 94-100%,e da quantidade de caudal superficial em aproximadamente 97%, ao nível da área de telhado verde, ao utilizar a ferramenta de controlo LID. No entanto, do ponto de vista da área de estudo a redução é na ordem dos 13-15% devido à grande dimensão da área de estudo, que possui uma baixa área de telhados que pode ser convertida em telhado verde.<br>Recent flooding all over the world have shown how vulnerable are urban areas to extreme hydrologic conditions. Urban sprawl combined with climate change increase rainfall runoff thus causing recurrent flooding. Rebuilding the drainage system may not be efficient or feasible, either technically or economically, to address this problem. Innovative techniques such as green roofs, pervious surfaces, swales, retention basins, among others, mitigate flood peaks thus reducing flood risk, and reduce the concentration of pollutants in rainfall runoff.
In this study is analysed the potential of green roofs in reducing peak flow and rainfall runoff as well as the sustainability of this technology, economically, socially and environmentally. The analysis was performed considering the application of this technology in the Campus II of the University of Coimbra using the hydraulic-hydrological modelling program Storm Water Management Model (SWMM), of the Environmental Protection Agency (EPA) of the United States of America (USA).
Results showed a peak flow reduction of 94-100% and rainfall runoff reduction of approximately 97%, concerning subcatchments with green roofs and by using the Low Impact Development (LID) control tool of SWMM. However, considering the entire area of the case study the reduction is of 13-15% due to the low area available to insert green roofs, in the large area of the case study.
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Paninho, Ana Inês Brandão. "Sustainable Intensification Strategies for the Production of Cyclic Carbonates from CO2." Doctoral thesis, 2018. http://hdl.handle.net/10362/43093.
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[ENG] Global warming, caused mostly by the increasing of greenhouse gas concentrations in the atmosphere, has became one of the most serious environmental concerns. Between the major greenhouse gases, carbon dioxide had the most significant increase. Its high availability, non-flammability, low toxicity and independency from the food supply chain, makes CO2 utilization as a carbon feedstock an important topic from both industrial and academic perspectives. The aim of this work was to develop process intensification strategies for cyclic carbonate production from CO2 and epoxides. Cyclic carbonates are versatile molecules which may become a future platform to introduce CO2 as a renewable carbon feedstock into the chemical sector. Indeed, cyclic carbonates find use in a wide range of applications as electrolytes for lithium batteries, polar aprotic solvents, pharmaceutical intermediates and also as monomers in polymer production.
For the first time, zinc (II) complexes of arylhydrazones of β-diketones (AHBD) combined with ionic liquids were used as catalysts for the production of cyclic carbonates. Different cation and anion families were explored in order to understand the effect of specific functional groups on the final reaction yield and selectivity. Results confirmed the importance of the nucleophilicity of the anion, with halogens presenting the better results. Regarding the cation structure, it was possible to conclude that the bulkiness of the structure was the more important factor to have in consideration. Also the effects of pressure, temperature, type of solvent and catalyst concentration were studied and a high-pressure extraction process for an efficient product separation and recycling of the catalytic system was proposed.
Finally, in the context of developing a green continuous flow process for CO2 conversion into cyclic carbonates, two different engineering approaches were investigated. On one hand a supported ionic liquid onto an alginate aerogel matrix was prepared, characterized and applied as catalytic system. On the other hand, a continuous flow process using a bulk ionic liquid phase as catalyst was carried out. Both processes allowed for cyclic carbonate production from a bio-based epoxide (limonene oxide) in the production of limonene carbonate, a 100% renewable cyclic carbonate.
This thesis provides new opportunities for cyclic carbonate production from CO2 and epoxides in the context of sustainable processing.<br>[PT] O aquecimento global provocado principalmente pelo aumento das concentrações de gases de efeito estufa na atmosfera tornou-se numa das mais sérias preocupações em termos ambientais. Entre os principais gases responsáveis pelo efeito de estufa, temos o dióxido de carbono. Pelo facto de estar bastante disponível, de ser não inflamável, ter baixa toxicidade e devido a sua independência em relação a cadeia alimentar, o uso do CO2 como matéria-prima tem vindo a ganhar muita atenção quer do ponto de vista industrial e quer académico. O objetivo deste trabalho consiste no desenvolvimento de estratégias de intensificação do processo responsável pela produção de carbonatos cíclicos a partir da reação de epóxidos com CO2. Por sua vez, os carbonatos cíclicos produzidos tem várias aplicações, podem ser utilizados como eletrólitos nas baterias de lítio, como intermediários farmacêuticos e também como monómeros para a produção de polímeros.
Pela primeira vez, complexos de zinco (II) de arilhidrazonas de -dicetonas combinados com líquidos iónicos foram utilizados como catalisadores na produção de carbonatos cíclicos. Diferentes famílias de aniões e catiões foram estudadas, com o objetivo de compreender o efeito destes grupos funcionais na selectividade e no rendimento final da reação. Os resultados confirmaram a importância da nucleofilicidade do anião, com os iões de halogénios a apresentar os melhores resultados.
Preservando à estrutura de catião, foi possível concluir que o tamanho da estrutura era o fator mais importante a ter em consideração. O efeito da pressão, temperatura, tipo de solvente e catalisador foram alguns dos parâmetros estudados, adicionalmente um processo de extração a alta pressão foi proposto como forma eficiente de separação do produto final e reutilização do catalisador.
Finalmente, com o objetivo de desenvolver uma tecnologia verde na conversão de CO2 em carbonatos cíclicos duas diferentes abordagens, em termos de engenharia, foram investigadas. Primeiro, foi preparado e devidamente caracterizado um catalisador suportado, composto por uma matriz de aerogéis de alginato, para posteriormente ser testado com sistema catalítico. Segundo, foi explorada a possibilidade de realizar esta reação em modo contínuo, utilizando com líquidos iónicos em “bulk” com catalisadores. Em ambos os processos foi possível a produção de carbonatos cíclicos a partir de um epóxido proveniente de recursos naturais (óxido de limoneno) produzindo assim carbonato de limoneno, um carbonato 100% bio-renovável.
Esta tese fornece novas oportunidades para aumentar a produtividade do processo de produção de carbonatos cíclicos a partir do CO2.<br>Doctoral fellowship PD/BD/52497/2014, FCT/MEC (UID/QUI/50006/2013), ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER - 007265), project EXPL/QEQ-ERQ/2243/2013, project “Sun Storage – Harvesting and storage of solar energy”, reference POCI-01-0145-FEDER-016387, FCT (RECI/BBB-BQB/0230/2012) e AQUA-CO2NV ENE2014-53459-R.