31 |
Métrologie par photogrammétrie aéroportée légère : application au suivi d'évolution de digues / Metrology with light aerial photogrammetry : application to dykes monitoringTournadre, Vincent 21 December 2015 (has links)
En embarquant un appareil photo grand public de bonne qualité sur un drone ou un ULM, il est aujourd'hui possible de réaliser de manière 100% automatique des modélisations 3D visuellement « parfaites » ou en tout cas suffisante tant que ce modèle est utilisé comme support de communication. Par contre, les performances de ces méthodes sont encore mal maîtrisées dans le contexte où l'on veut utiliser le modèle comme outil de mesure. Les géométries d'acquisition linéaires, propices aux dérives de bandes photogrammétriques, en sont un exemple représentatif. Un phénomène de courbure de bande est alors constaté, nécessitant un travail de mesure terrain conséquent pour être corrigé. Ces imprécisions limitent l'intérêt de telles acquisitions, et sont un défi pour la communauté des photogrammètres, le marché naissant du drone, mais aussi de multiples industriel ayant un intérêt fort pour des systèmes capables d'assurer un suivi de mouvement 3D des sols avec une précision de quelques millimètres (par exemple suivi de digues, érosion agraire, surveillance de réseaux ferrés,...). Cette thèse est un projet de recherche issu d'un partenariat entre l'Institut National de l'Information Géographique et Forestière (IGN), et la Compagnie Nationale du Rhône (CNR), concessionnaire chargé d'entretenir et surveiller le réseau de digues de retenue du fleuve. Il s'agit - à partir de moyens aériens légers - d'arriver à un système d'auscultation plus rapide, plus économique et offrant une géométrie plus fine que les systèmes topométriques utilisés actuellement. Nous présentons tout d'abord une étude comparative des moyens aériens légers, montrant l'intérêt et les limitations des drones face aux ULM. Nous proposons des procédures d'acquisition adaptées aux géométries étudiées, permettant de limiter de manière opérationnelle les dérives. Dans un second temps, nous montrons que les phénomènes de courbure sont liés à des modèles d'orientation internes inadaptés, et nous proposons une procédure d'auto-calibration en trois étapes. Nos essais menés sur des chantiers linéaires montrent que le calcul des orientations est sensiblement amélioré (d'écarts métriques à des écarts centimétriques). Dans un troisième temps, nous proposons une optimisation de la compensation sur les points d'appuis, permettant de diminuer le nombre de mesures nécessaires. Enfin, nous présentons des méthodes pour contrôler l'incertitude des modèles 3D générés, et à travers une analyse diachronique, des exemples de suivi d'évolution permettant de suivre finement l'évolution de tels ouvrages / By embarking a good quality consumer grade camera on an Unmanned Aerial Vehicle (UAV) or on an ultralight system, it is possible to create – fully automatically – 3D models that are visually ''perfect'', or at least sufficient for visual or communication purposes. However, the accuracy of these methods is still a concern, especially if the resulting models are to be used as measuring tools. Linear acquisitions – also known as corridor mapping – are a striking example of the uncontrolled error propagation. A bowl effect is often observed, requiring multiple ground measurements to be overcome. These effects restrict the interest of such acquisitions. They are a challenge for the photogrammetrists community, the emerging civil UAV market, as well as many industrials interested in systems able to monitor ground deformations with an accuracy within a few millimeters (railway network surveillance, erosion of agricultural land, embankments monitoring,…).This thesis is an applied research project, led with a river concessionary which has the responsibility to maintain and keep under surveillance its containment dykes network. The purpose is to use light aerial systems as a mean for a monitoring system which is faster, cheaper, and more detailed than the topometric solutions used so far. First of all, we present a comparative study to understand, between UAVs and ultralight system, which tool is the most adapted for a specific need. We propose refined acquisition procedures, than can be used to limit operationally the drifts. In a second phase, we identify the internal camera model as the weak link, and propose a three steps auto-calibration procedure. Our tests led on linear acquisitions demonstrate that the external orientations accuracy are noticeably improved (from decimetric or even metric disparities, reduced to a few centimeters or less). In a third part, we propose an optimization of the adjustment on the ground control points, which is a way to limit the amount of ground measurements necessary. Finally, we present methods to control 3D models uncertainty, and through a diachronic analysis, examples of how such data can be used to monitor such structures through time
|
32 |
Studies On The Application Of Liquid Membranes For The Removal Of Dissolved Metals From EffluentsKumar, Vijaya S 06 1900 (has links)
Separation of dissolved metals from aqueous solutions using liquid membrane technology is highly advantageous owing to the degree of separation achieved, efficiency and application potential. In the present investigation four types of liquid membranes - bulk liquid membrane (BLM), emulsion liquid membrane (ELM), electrostatic pseudo liquid membrane (ESPLIM) and unified liquid membrane (ULM) have been extensively studied, for their application in extraction and concentration of dissolved metals from effluents. Experiments were conducted with various metal systems to optimize both system and process conditions and to find out the effect of various parameters on the performance of the process. Different mass transport models were proposed for each type, taking diffusional and kinetic resistances into account. Models were extended for simultaneous extraction systems and were verified by different metal-carrier experiments. Good agreement was found between the concentration profiles obtained from the models and the experimental data, thereby establishing the validity of models for all the four types of liquid membranes.
The stirred cell employed in BLM process eliminates emulsification and demulsification processes. It also provides simultaneous contact of the organic liquid membrane phase with aqueous feed and strip phases. Overall rate expressions for extraction and stripping in BLM are based on an assumed kinetic mechanism to explain the process qualitatively. It was found that the magnitude^ of diffusional and kinetic resistances determines the overall mass transfer coefficient. The relative magnitude of mass transfer coefficient, reaction rate constants and equilibrium constants enables to visualize the controlling regime of the process.
The problem of low flux rate due to high diffusion resistances, inefficient operation and exorbitant costs encountered in bulk and supported liquid membranes (SLM) are overcome in an ELM. In the ELM process, an emulsion of organic membrane phase and aqueous inner phase, is dispersed in the continuous aqueous feed phase. This gives a highly selective and ultra thin liquid film generating a large mass transfer area for separation. Experimental results on membrane instability and emulsion swelling indicate that volumetric leakage rate depends linearly on the stirring speed and that the nature of surfactant does not have any appreciable effect on emulsion swelling. A general permeation model was developed taking into account the external mass transfer around the emulsion drop, diffusion in the drop, reaction at the aqueous-organic interface, leakage of the internal phase to the external phase due to membrane breakup and emulsion swelling due to osmotic pressure difference. Model equations with appropriate boundary conditions were numerically solved by orthogonal collocation technique for a set of model parameters obtained either from known correlations or from independent experiments. Comparison of the model predictions with experimental data from the batch permeation of chromium and other metals using carrier Alamine 336 or LIX 64N, shows that the model predictions are in very good agreement with the experimental findings. Further this model can be used to simulate the effects of various experimental conditions such as metal and hydrogen ion concentrations, carrier concentration, drop diameters, etc., for similar systems.
Studies on ESPLIM were conducted with the aim of demonstrating the effectiveness of this new separation process and to develop a simple transport model for metal permeation. In the ESPLIM process, a high electrical field (3-5 kV A.C.) is used for phase dispersion. This system consists of a rectangular reactor filled with membrane solution divided into extraction and stripping cells by a centrally placed integrated type baffle which also acts as an electrode. Two more electrodes were placed in the extraction and stripping cells, where feed and strip phases are introduced from the top of the reactor. When high electrical field is applied across the electrodes, fine droplets of feed and strip are formed and are dispersed in extraction and stripping cells where simultaneous extraction and stripping occurs. The process can be viewed as simultaneous counter current extraction and stripping. The aqueous drops coalesce in the settlers at the bottom of the reactor and are removed continuously. Steady state mass transport model proposed for ESPLIM system accounts for the vertical counter-current extraction and stripping processes taking place in the extraction and stripping cells, together with the lateral transport process of the metal-complex and carrier across the two cells through the integrated baffle zone. The model equations were solved analytically to obtain concentration profiles as a function of the height of the reactor. The required parameters such as mass transfer coefficients, diffusion coefficients etc. were estimated using different correlations. Model predictions agreed remarkably well with the experimental data under various process conditions. From this investigation, it was found that ESPLIM is a simple, efficient and economical process and can be applied in a variety of situations.
Based on a suitable combination of solvent extraction, dispersion and liquid membrane technique, a new type of separation system called " Unified Liquid Membrane " was developed. The ULM unit was designed and fabricated, and experiments were conducted to evaluate its performance. The ULM is basically derived from ESPLIM by changing the reactor, baffle design and dispersion technique. Aqueous feed and strip phases were atomized using compressed air through a fine nozzle and are dispersed on either side of an integrated baffle plate that divides the reactor into extraction and stripping cells. Tapering bottom of the reactor reduces the dead volume of the liquid in the settlers and the baffle plate remarkably reduces the leakage problem as well as the resistance through the baffle. Experiments were conducted using LIX 64N and Alamine 336 as carriers for copper and chromium and / or zinc. Mass transport model proposed considers both chemical and phase equilibria in extraction and stripping cells, vertical and lateral transport of carrier and complex across the extraction and stripping cells through the baffle zone. The model equations were solved using initial conditions at the top of the reactor, and equilibrium data for extraction and stripping cells. Effect of various experimental conditions and process parameters was simulated using this model and the model predictions are found to be in excellent agreement with the experimental data. The ULM system developed in this investigation overcomes the major limitations encountered with the other types of liquid membranes while retaining all the advantages of this technology. The problem of high mass transfer resistance from bulk phase to metal permeation as in the case of BLM was eliminated by good phase dispersion. Additional resistance to mass transport from solid membrane as in the case of SLM was removed by using an integrated baffle which also avoids problems of membrane instability, pore clogging and selectivity. The complex problems of emulsification and demulsification were completely eliminated making the system much simpler and efficient. Very good phase dispersion was obtained by atomization without the need for either stirring the whole system or application of high electrical field in the reactor. The membrane liquid within the integrated baffle elements allows easy transport of different species between extraction and stripping cells while completely preventing the mixing of the two aqueous phases. The problems of leakage, swelling and occlusion were avoided due to very short residence time of the aqueous drops in the reactor. It was found that the new ULM configuration is simple, elegant, highly efficient and superior to the other types of liquid membrane systems.
|
33 |
Haltfallbewertung unter ETCSBolay, Julius 01 June 2023 (has links)
Eine Signalhaltstellung wird regulär herbeigeführt, wenn der Zug, für den das Signal gilt, dieses passiert hat. Der Zug wird dann gedeckt. Fallen vorzeitig die Freigabebedingungen weg, wird das Signal ebenfalls auf Halt gestellt. Hier ist vom irregulären Signalhaltfall die Rede. Bei punktförmigen Zugbeeinflussungssystemen wird die zum Signal gehörende Sendeeinrichtung der Zugbeeinflussung unmittelbar wirksam. Bei linienförmigen Zugbeeinflussungssystemen wie dem European Train Control System (ETCS) in der Ausprägung Level 2 (L2) findet ein kontinuierlicher Informationsaustausch zwischen Fahrzeug und Strecke statt. Im Fall von ETCS L2 erfolgt dies über Funk, was besondere Anforderungen an die Bewertung des Signalhaltfalls stellt. Es wird berechnet, ob das Fahrzeug das Signal sicher passiert hat. In den erforderlichen Übertragungs- und Verarbeitungszeiten wird speziell im deutschen ETCS eine Sicherheitslücke gesehen. Diese wird durch Implementierung mehrerer umfangreicher Berechnungsverfahren innerhalb ETCS kompensiert.
Die vorliegende Arbeit analysiert diese Berechnungsverfahren im Detail sowie alle denkbaren Gründe für irreguläre Signalhaltfälle. Es werden Überlegungen angestellt, wie diese Berechnungen vereinfacht werden können und wie es gelingt, alle denkbaren, irregulären Signalhaltfälle bereits direkt durch das Stellwerk zu erkennen. Hierfür bietet die Neuordnung der Produktionssteuerung (NeuPro) neue Stellwerks-Architekturen mit neuen Möglichkeiten, die so bisher nicht bestanden. Auf diesem Weg können auch in Deutschland die Berechnungsverfahren verschlankt sowie Komponenten in der Außenanlage (Achszählpunkte und Balisen) eingespart werden. Es ist technisch sinnvoll, die Berechnungen, unter ETCS so schlank wie möglich zu halten, denn die ETCS-Streckenzentrale (ETCS-Z), die Fahrerlaubnisse verwaltet, kann bei weniger Rechenaufwand mehr Züge führen. Darüber hinaus wird auch ein Blick auf die Haltfallbewertung beim ETCS der Bahnen in benachbarten Ländern geworfen. Des Weiteren wird geprüft, inwieweit die Laufzeitlücke angesichts technischer Weiterentwicklungen verkleinert werden kann. Die Arbeit schließt mit einem Blick in die fernere Zukunft, wenn Abkehr von der klassischen blockzentrischen Fahrzeugortung genommen wird und das Fahren im wandernden Raumabstand das klassische Fahren im festen Raumabstand ablöst. Feste Signalstandorte werden dann der Vergangenheit angehören und somit wird auch keine Haltfallbewertung mehr erforderlich sein. Den Weg dorthin sollen die Impulse dieser Arbeit vereinfachen.:1. Ausgangssituation und Ziele
2. Lösungsansätze zu Vereinfachung oder Entfall der Haltfallbewertung
3. Auswertung und Empfehlung / A signal closure is regularly brought about when the train to which the signal applies has passed it. The train is then covered. If the signal enabling conditions cease to apply prematurely, the signal is also closed. This is called irregular signal closure. In the case of intermittent automatic train control, the transmitting device of the train control system, associated with the signal, becomes effective immediately. With continuous automatic train control systems such as the European Train Control System (ETCS) in Level 2 (L2), there is a continuous exchange of information between the vehicle and the trackside. In the case of ETCS L2, this takes place via radio, which places special demands on the evaluation of the signal closure case. On the one hand, it must be calculated whether the vehicle has passed the signal safely and, especially in the German ETCS, great safety significance is attributed to the transmission and processing time. The resulting safety gap was compensated in the German ETCS by implementing several extensive calculation procedures within ETCS. This thesis analyses these calculation methods in detail as well as all conceivable reasons for irregular signal closures. Considerations are made as to how these calculations can be simplified and how it is possible to detect all conceivable irregular signal stops directly by the interlocking. For this purpose, the reorganisation of production control (Neuordnung der Produktionssteuerung, NeuPro) offers new interlocking architectures with new possibilities that have not existed before. This way, the calculation procedures can also be streamlined in Germany and components such as axle counting points and balises in the external system can be saved on. It makes sense from a technical perspective to keep the calculations under ETCS as lean as possible because the Radio Block Centre (RBC), which administers driving permits, can run more trains with less computing effort. In addition, the ETCS stop case evaluation of the railways in neighbouring countries is described. Furthermore, it is examined to what extent the running time gap can be reduced in view of further technical developments. The thesis concludes with a look into the distant future, when the classic block-centric vehicle location system will be abolished and driving in a wandering space interval will replace the classic driving in a fixed space interval. Fixed signal locations will then be a thing of the past and thus a stop assessment will no longer be necessary. The impulses of this work should simplify the way there.:1. Ausgangssituation und Ziele
2. Lösungsansätze zu Vereinfachung oder Entfall der Haltfallbewertung
3. Auswertung und Empfehlung
|
34 |
Towards Control of Dutch Elm Disease: dsRNAs and the Regulation of Gene Expression in Ophiostoma novo-ulmi / dsRNAs and the Regulation of Gene Expression in Ophiostoma novo-ulmiCarneiro, Joyce Silva 01 August 2013 (has links)
Ophiostoma novo-ulmi is the causal agent of Dutch elm disease (DED) which has had a severe impact on the urban landscape in Canada. This research program focused on developing molecular genetic strategies to control this pathogenic fungus.
The first strategy involved the development of RNA interference (RNAi) for the down-regulation of genes involved in pathogenicity. An efficient RNAi cassette was developed to suppress the expression of the endopolygalacturonase (epg1) locus which encodes a cell-wall degrading enzyme. This epg1-RNAi cassette significantly reduced the amount of polygalacturonase activity in the fungus and resulted in almost complete degradation of epg1 mRNA. The need for a native promoter to selectively down-regulate specific gene loci was addressed by developing a carbon-catabolite regulated promoter (alcA) to drive the expression of the epg1-RNAi cassette. The expression of an alcA-driven epg1-RNAi cassette resulted in the down-regulation of epg expression under glucose starvation but normal levels of expression in high glucose. The expression could therefore be controlled by culture conditions.
The second strategy explored the potential of using dsRNA viruses to vector disruptive RNAi cassettes. An isolate of O. novo-ulmi strain 93-1224 collected in the city of Winnipeg, was infected by two dsRNA mitoviruses which upon sequence characterization were named OnuMV1c and OnuMV7.
To assess the transmissibility of this dsRNA virus the infected isolate 93-1224 was paired with three naive isolates of the related fungi O. ulmi and O. himal-ulmi. Through the use of nuclear and mitochondrial markers it was determined that the virus OnuMV1c may not rely on mitochondrial fusion for transmission but may have a cytoplasmic transmission route.
This investigation of gene expression and manipulation has provided tools to help understand gene regulation in O. novo-ulmi. It has also added to our knowledge of mitoviruses, their transmission and potential use as a biological control. By enhancing our understanding of transmissible hypovirulence this work contributes to efforts to develop a new approach to target DED as well as a potential model for the control of other fungal diseases. / Graduate / 0307 / 0306 / 0369 / jscarneiro@hotmail.com
|
35 |
Mistr Hartmann a švábské sochařství počátku 15. století / Master Hartmann and the Swabian Woodcarving at the Beginning of the 15th CenturyHladká, Kateřina January 2017 (has links)
Master Hartmann and the Swabian Woodcarving at the Beginning of the 15th Century The stonemason Master Hartmann from Ulm is known to art historians already long time, but his role in Swabian woodcarving at the beginning of the 15th century, however, still evokes numerous questions. Although Hartmann is believed to work simultaneously in the hut and the woodcarving workshop, the average quality of his works, and the fact, that he was accepted as a citizen only in the year 1928, more than ten years after we encounter him in Ulm records for the first time, indicates certain complications of this hypothesis. In this doctoral thesis, Master Hartmann is studied from the perspective of social and cultural situation in Ulm at the beginning of the 15th century. Attention is given to his position in the hut organization on the construction of Ulm Minster and his artistic activity on the western façade, which in its iconographical concept reflects also the historical background. The second part of the thesis focuses on the woodcarving workshop, where the Altarpiece of Dornstadt was made, and on the phenomenon of wide distribution of this style around the entire Swabia. The Ulm workshop is presented in the context of the city and its minster hut, former local centers and even more distant regions. Around 1415,...
|
36 |
Jahresbericht 2015 / Universitätsbibliothek Chemnitz / Annual Report 2015 / University Library of ChemnitzMalz, Angela 26 September 2016 (has links) (PDF)
Jahresbericht der Universitätsbibliothek Chemnitz und des Universitätsarchivs- Berichtsjahr 2015 / Annual report of the University Library of Chemnitz and the University Archive in 2015
|
37 |
Jahresbericht 2015 / Universitätsbibliothek ChemnitzMalz, Angela 26 September 2016 (has links)
Jahresbericht der Universitätsbibliothek Chemnitz und des Universitätsarchivs- Berichtsjahr 2015 / Annual report of the University Library of Chemnitz and the University Archive in 2015
|
Page generated in 0.0256 seconds