Vortex dynamics in turbulence

We survey attempts to construct vortex models of the inertial-range and fine-scale range of high Reynolds number turbulence. An emphasis is placed on models capable of quantitative predictions or postdictions

CAD-Based Porous Scaffold Design of Intervertebral Discs in Tissue Engineering

With the development and maturity of three-dimensional (3D) printing technology over the past decade, 3D printing has been widely investigated and applied in the field of tissue engineering to repair damaged tissues or organs, such as muscles, skin, and bones, Although a number of automated fabrication methods have been developed to create superior bio-scaffolds with specific surface properties and porosity, the major challenges still focus on how to fabricate 3D natural biodegradable scaffolds that have tailor properties such as intricate architecture, porosity, and interconnectivity in order to provide the needed structural integrity, strength, transport, and ideal microenvironment for cell- and tissue-growth. In this dissertation, a robust pipeline of fabricating bio-functional porous scaffolds of intervertebral discs based on different innovative porous design methodologies is illustrated. Firstly, a triply periodic minimal surface (TPMS) based parameterization method, which has overcome the integrity problem of traditional TPMS method, is presented in Chapter 3. Then, an implicit surface modeling (ISM) approach using tetrahedral implicit surface (TIS) is demonstrated and compared with the TPMS method in Chapter 4. In Chapter 5, we present an advanced porous design method with higher flexibility using anisotropic radial basis function (ARBF) and volumetric meshes. Based on all these advanced porous design methods, the 3D model of a bio-functional porous intervertebral disc scaffold can be easily designed and its physical model can also be manufactured through 3D printing. However, due to the unique shape of each intervertebral disc and the intricate topological relationship between the intervertebral discs and the spine, the accurate localization and segmentation of dysfunctional discs are regarded as another obstacle to fabricating porous 3D disc models. To that end, we discuss in Chapter 6 a segmentation technique of intervertebral discs from CT-scanned medical images by using deep convolutional neural networks. Additionally, some examples of applying different porous designs on the segmented intervertebral disc models are demonstrated in Chapter 6

Aspects of sensory cues and propulsion in marine zooplankton hydrodynamic disturbances

The hydrodynamic disturbances generated by two types of free-swimming, marine zooplankton were quantified experimentally in the laboratory with a novel, infrared Particle Image Velocimetry (PIV) system. The study consisted of three main parts: (1) the flow fields of free-swimming and tethered Euchaeta antarctica were compared to determine the effects of tethering, (2) three species of copepods (Euchaeta rimana, Euchaeta elongata, and Euchaeta antarctica) that live in seawater in a range of temperatures (23 ºC - 0 ºC) and a corresponding range of fluid viscosity (0.97 - 1.88 mm2 s-1) were analyzed experimentally and with a computational fluid dynamics model (FLUENT) to assess the effect of size and fluid viscosity on the flow fields, (3) the flow fields were collected for individuals of two species of euphausiids (Euphausia pacifica and Euphausia superba) to compare the effect of size and Reynolds number on propulsion and the spatial extent of the flow disturbance. In addition to the measured flow fields around solitary krill, flow fields were collected around small, coordinated groups of E. superba to examine group sensory cues through hydrodynamics. In the first part of this investigation, it was determined that tethering zooplankton during data collection resulted in flow fields with increased asymmetry and larger spatial extent due to the unbalanced force applied to the fluid by the tether. In response to these findings, only flow fields collected for free-swimming organisms were used in the subsequent studies. In the second part of the study, the increase in viscosity between subtropical and temperate fluid environments in conjunction with increased size and species-specific swimming speeds resulted in similar Reynolds numbers among E. elongata and E. rimana (in both cruising and escaping modes). During cruising (Re ~10), the spatial extent of the copepod hydrodynamic disturbances and propulsion costs were similar between species. In the case of fluid distrubances of escape (Re ~ 100), the spatial extent and energetic cost were larger for the larger species ( E. elongata). In the third part of the study, the hydrodynamic disturbance produced by E. superba (larger krill species) was found to be longer in horizontal spatial extent and at scales more appropriate for communication within schools than the hydrodynamic disturbance produced by E. pacifica. However, the sensory cue in coordinated groups of krill was complicated by the interaction of multiple flow disturbance fields, which suggests that hydrodynamic cues between krill in groups are restricted to small distances. The energetic cost of propulsion was ten times greater for the larger species of krill, and energetic expenditure did not appear to decrease for krill swimming in coordinated groups.Ph.D.Committee Chair: Dr. Donald Webster; Committee Co-Chair: Dr. Jeannette Yen; Committee Member: Dr. Philip Roberts; Committee Member: Dr. Terry Sturm; Committee Member: Dr. Thorsten Stoesse

Developing advanced mathematical models for detecting abnormalities in 2D/3D medical structures.

Detecting abnormalities in two-dimensional (2D) and three-dimensional (3D) medical structures is among the most interesting and challenging research areas in the medical imaging field. Obtaining the desired accurate automated quantification of abnormalities in medical structures is still very challenging. This is due to a large and constantly growing number of different objects of interest and associated abnormalities, large variations of their appearances and shapes in images, different medical imaging modalities, and associated changes of signal homogeneity and noise for each object. The main objective of this dissertation is to address these problems and to provide proper mathematical models and techniques that are capable of analyzing low and high resolution medical data and providing an accurate, automated analysis of the abnormalities in medical structures in terms of their area/volume, shape, and associated abnormal functionality. This dissertation presents different preliminary mathematical models and techniques that are applied in three case studies: (i) detecting abnormal tissue in the left ventricle (LV) wall of the heart from delayed contrast-enhanced cardiac magnetic resonance images (MRI), (ii) detecting local cardiac diseases based on estimating the functional strain metric from cardiac cine MRI, and (iii) identifying the abnormalities in the corpus callosum (CC) brain structure—the largest fiber bundle that connects the two hemispheres in the brain—for subjects that suffer from developmental brain disorders. For detecting the abnormal tissue in the heart, a graph-cut mathematical optimization model with a cost function that accounts for the object’s visual appearance and shape is used to segment the the inner cavity. The model is further integrated with a geometric model (i.e., a fast marching level set model) to segment the outer border of the myocardial wall (the LV). Then the abnormal tissue in the myocardium wall (also called dead tissue, pathological tissue, or infarct area) is identified based on a joint Markov-Gibbs random field (MGRF) model of the image and its region (segmentation) map that accounts for the pixel intensities and the spatial interactions between the pixels. Experiments with real in-vivo data and comparative results with ground truth (identified by a radiologist) and other approaches showed that the proposed framework can accurately detect the pathological tissue and can provide useful metrics for radiologists and clinicians. To estimate the strain from cardiac cine MRI, a novel method based on tracking the LV wall geometry is proposed. To achieve this goal, a partial differential equation (PDE) method is applied to track the LV wall points by solving the Laplace equation between the LV contours of each two successive image frames over the cardiac cycle. The main advantage of the proposed tracking method over traditional texture-based methods is its ability to track the movement and rotation of the LV wall based on tracking the geometric features of the inner, mid-, and outer walls of the LV. This overcomes noise sources that come from scanner and heart motion. To identify the abnormalities in the CC from brain MRI, the CCs are aligned using a rigid registration model and are segmented using a shape-appearance model. Then, they are mapped to a simple unified space for analysis. This work introduces a novel cylindrical mapping model, which is conformal (i.e., one to one transformation and bijective), that enables accurate 3D shape analysis of the CC in the cylindrical domain. The framework can detect abnormalities in all divisions of the CC (i.e., splenium, rostrum, genu and body). In addition, it offers a whole 3D analysis of the CC abnormalities instead of only area-based analysis as done by previous groups. The initial classification results based on the centerline length and CC thickness suggest that the proposed CC shape analysis is a promising supplement to the current techniques for diagnosing dyslexia. The proposed techniques in this dissertation have been successfully tested on complex synthetic and MR images and can be used to advantage in many of today’s clinical applications of computer-assisted medical diagnostics and intervention

Process control for WAAM using computer vision

This study is mainly about the vision system and control algorithm programming for wire arc additive manufacturing (WAAM). Arc additive manufacturing technology is formed by the principle of heat source cladding produced by welders using molten inert gas shielded welding (MIG), tungsten inert gas shielded welding (TIG) and layered plasma welding power supply (PA). It has high deposition efficiency, short manufacturing cycle, low cost, and easy maintenance. Although WAAM has very good uses in various fields, the inability to control the adding process in real time has led to defects in the weld and reduced quality. Therefore, it is necessary to develop the real-time feedback through computer vision and algorithms for WAAM to ensure that the thickness and the width of each layer during the addition process are the same

Applications of Mathematical Models in Engineering

The most influential research topic in the twenty-first century seems to be mathematics, as it generates innovation in a wide range of research fields. It supports all engineering fields, but also areas such as medicine, healthcare, business, etc. Therefore, the intention of this Special Issue is to deal with mathematical works related to engineering and multidisciplinary problems. Modern developments in theoretical and applied science have widely depended our knowledge of the derivatives and integrals of the fractional order appearing in engineering practices. Therefore, one goal of this Special Issue is to focus on recent achievements and future challenges in the theory and applications of fractional calculus in engineering sciences. The special issue included some original research articles that address significant issues and contribute towards the development of new concepts, methodologies, applications, trends and knowledge in mathematics. Potential topics include, but are not limited to, the following: Fractional mathematical models; Computational methods for the fractional PDEs in engineering; New mathematical approaches, innovations and challenges in biotechnologies and biomedicine; Applied mathematics; Engineering research based on advanced mathematical tools

Continuous monitoring of tree responses to climate change for smart forestry: a cybernetic web of trees

6openBothTrees are long-lived organisms that contribute to forest development over centuries and beyond. However, trees are vulnerable to increasing natural and anthropic disturbances. Spatially distributed, continuous data are required to predict mortality risk and impact on the fate of forest ecosystems. In order to enable monitoring over sensitive and often remote forest areas that cannot be patrolled regularly, early warning tools/platforms of mortality risk need to be established across regions. Although remote sensing tools are good at detecting change once it has occurred, early warning tools require ecophysiological information that is more easily collected from single trees on the ground. Here, we discuss the requirements for developing and implementing such a treebased platform to collect and transmit ecophysiological forest observations and environmental measurements from representative forest sites, where the goals are to identify and to monitor ecological tipping points for rapid forest decline. Long-term monitoring of forest research plots will contribute to better understanding of disturbance and the conditions that precede it. International networks of these sites will provide a regional view of susceptibility and impacts and would play an important role in ground-truthing remotely sensed data.openTognetti, Roberto; Valentini, Riccardo; Belelli Marchesini, Luca; Gianelle, Damiano; Panzacchi, Pietro; Marshall, John D.Tognetti, R.; Valentini, R.; Belelli Marchesini, L.; Gianelle, D.; Panzacchi, P.; Marshall, J.D

Modelling and control of laser surface treatment

The results of laser surface treatment may vary significantly during laser surface processing. These variations arise from the sensitivity of the process to disturbances, such as varying absorptivity and the small dimensions of the work piece. To increase the reproducibility of the process, a real-time feedback control system was designed and tested. Process models were developed to gain insight in the process behavior. As a test case, laser alloying of titanium (Ti6Al4V) with nitrogen was considered. Unfortunately, not all the desired processing results, such as the thickness of the alloyed layer, can be measured during processing. The quantities, which can be measured, are temperature related, e.g. the melt pool temperature and the melt pool surface area. Dynamic and steady-state models were developed, which relate the processing results to the measured quantities. A thermographic CCD camera was developed to measure the melt pool surface area in real-time. Pyrometers were applied to measure its temperature. The effects of the laser power, the beam velocity and the disturbances (absorptivity, thin work piece) on the temperature distribution and melt pool surface area, were analyzed theoretically, as well as experimentally. The width and length of the temperature distribution and the melt pool vary due to the disturbances. In the case of a thin work piece, the length varies more than the width. In the case of an absorptivity disturbance, the variation of the length and width are of the same order. In addition, it was found that the laser power can be best applied to counteract an absorptivity disturbance. The beam velocity can be best applied to suppress the negative effects introduced by small dimensions of the work piece. Based on these results, several controller algorithms, including multivariable algorithms, were implemented and tested. A mode-switch controller was able to produce a constant melt pool depth despite disturbances. This controller applied the laser power to suppress an absorptivity disturbance, and the beam velocity to counteract a geometrical disturbance. Hence, although it is not possible to measure the thickness of the alloyed layer directly, it is possible to control it by measuring and controlling temperature related quantities (temperature, melt pool area) at the surface

Experimental and Theoretical Analyses of Adiabatic Two-phase Flows in Horizontal Feed Pipes

The majority of technical separation processes for fluid mixtures utilize the principle of rectification. If a two-phase mixture is fed into the column, possibly undesirable flow morphologies or severe droplet carry-over may occur, which detrimentally affect separation efficiency and equipment integrity. Currently, the two-phase flow behavior in feed pipes is hardly predicable and mostly based on empirical or heuristic methods, which do not properly account for a broad range of possible fluid properties and plant dimensions. As a consequence, costly safety margins are applied. Feed pipes to separation columns are often characterized by horizontal inlet nozzles, small length-to-diameter ratios and complex routing, involving elbows or bends. The pipe lengths are too short to enable the two-phase flow to fully develop, which thus, enters the column with unknown flow morphology. Since developing flows have rarely been studied, today’s engineering practice relies on existing predictive methods for fully developed two-phase flows. Graphical methods can hardly represent gradual transitions between flow regimes. Analytical models provide only simplified flow representations of the two-phase flow that have not yet been qualified for developing pipe flow. In this work, a comprehensive experimental database of horizontal water-air flows in two test sections with nominal pipe diameters of D = 50 mm and D = 200 mm and feed pipe lengths in the range 10 < L/D < 75 was established. This way, the data cover developing pipe flows with entrance lengths typical for two-phase feeds of separation columns and more developed flows that are comparable with the extensively studied reference system water-air. A particular focus was put on the effect of pipe bends on the flow morphology up- and downstream. The flow morphology was captured using imaging wire-mesh sensors. A 4D fuzzy algorithm was applied to objectively identify the flow two-phase morphologies. Based on their fuzzy representation, the flow morphologies were classified and a novel 2D visualization technique is proposed to discuss the flow development along the feed pipes. Undesired flow morphologies (intermittent flow and entrainment) during the operation of two-phase feeds are hardly predictable by conventional design tools. The inception of intermittent flows was analyzed using the experimental data. Consequently, the inception criteria based on the required liquid levels for fully developed intermittent flows were adapted for short entrance lengths. The characteristic dynamics of flow morphologies that are known to cause the onset of entrainment were analyzed. Based on wave frequencies, a predictive criterion for the susceptibility of wavy flows for the onset of entrainment is introduced and applied to straight feed pipes and horizontal 90° bends. Among the dozens available, 66 reduced-order models for the prediction of the void fraction were tested for straight feed pipes and horizontal 90° pipe bends. Thereof, the ones most suitable for variable operating conditions and pipe geometries were identified and adapted. Complementary 3D simulations were performed to verify the applicability of numerical codes (VoF, AIAD) for flows with free interfaces. The flow morphologies were successfully reproduced at macroscopic scale, however, the simulation results rank behind reduced-order models considering their quantitative predicting capabilities.:Abstract II Kurzfassung IV Acknowledgement VI Nomenclature VIII Table of Contents XIII 1 Introduction 1 1.1 Thermal separation in view of the 21st century 1 1.2 Engineering and design of rectification plants 2 1.3 Outline of the thesis 4 2 State of the art 5 2.1 Two-phase feeds in thermal separation 5 2.1.1 Feed condition as adjustable parameter 5 2.1.2 Thermohydraulic optimization 8 2.1.3 Hydrodynamic conditioning 9 2.2 Hydrodynamics of two-phase feeds 11 2.2.1 Flow morphologies in feed pipes 11 2.2.2 Droplet entrainment 14 2.2.3 Flow regime maps 17 2.2.4 Consequences for two-phase feeds 19 2.3 Modelling of two-phase feeds 23 2.3.1 Basic definitions 23 2.3.2 Fundamentals of the two-fluid model 25 2.3.3 The interfacial level gradient 29 2.3.4 Analytical models 32 2.3.5 CFD simulations for commercial feed pipes 34 2.4 Objectives of this thesis 36 3 Experimental method and algorithms for flow characterization 37 3.1 Experimental setups 37 3.2 Wire-mesh sensors 40 3.3 Experimental procedure 42 3.4 Data processing 44 3.4.1 Fuzzy flow morphology classification 45 3.4.2 Power spectral density 48 3.5 Measurement uncertainty 49 4 Flow morphologies in different feed pipe geometries 53 4.1 Developing two-phase flow in straight pipes 53 4.2 Effect of pipe curvatures on the flow morphology 55 4.3 Morphology recovery 57 4.4 Conclusions 60 5 Prediction of undesirable flow morphologies in feed pipes 61 5.1 Initiation of intermittent flows 61 5.2 Onset of droplet entrainment 62 5.2.1 Vulnerable flow morphologies 62 5.2.2 Derivation of a criterion for onset of entrainment 64 5.2.3 Adjustment of the criterion for the investigated pipe geometries 67 5.3 Conclusions 70 6 Reduced-order modelling of two-phase feeds 71 6.1 Prediction of void fraction 71 6.2 Liquid levels 75 6.3 Conclusions 78 7 CFD modelling of two-phase feeds 79 7.1 Simulation setup 79 7.2 Multiphase models 82 7.3 Comparison with experimental data 83 7.3.1 Straight pipes 83 7.3.2 Horizontal 90° bends 85 7.4 Conclusions 88 8 Summary and recommendations for future work 89 8.1 Summary 89 8.2 Recommendations for future work 91 References 94 List of figures 113 List of tables 118 Appendix i Scientific publications and contributions xxxiii Eidesstattliche Erklärung xxxviiDie meisten technischen Verfahren zur Trennung von Flüssigkeitsgemischen beruhen auf dem Prinzip der Rektifikation. Wird ein Zweiphasengemisch in die Trennkolonne eingespeist, können unerwünschte Strömungsmorphologien oder ausgeprägte Tröpfchenverschleppung auftreten, welche sich nachteilig auf die Trennleistung und die Integrität einzelner Anlagenkomponenten auswirken. Derzeit lässt sich das Verhalten solcher Zweiphasenströmungen in Einspeiseleitungen kaum vorhersagen und basiert meist auf empirischen oder heuristischen Methoden, die ein breites Spektrum möglicher Stoffeigenschaften und Anlagendimensionen nicht angemessen berücksichtigen. Infolgedessen müssen kostspielige Sicherheitszuschläge angewendet werden. Einspeiseleitungen von Trennkolonnen sind häufig durch horizontale Eintrittsstutzen, ein geringes Länge-zu-Durchmesser-Verhältnis und eine komplexe Leitungsführung mit Bögen und anderen Normteilen gekennzeichnet. Typische Rohrlängen sind zu kurz, um eine vollständig entwickelte Zweiphasenströmung auszubilden, welche daher mit unbekannter Strömungs-morphologie in die Trennkolonne eintritt. Da derartige Strömungen jedoch bisher nur selten untersucht wurden, verlässt man sich gegenwärtig in der technischen Praxis auf bestehende Vorhersagemethoden für voll entwickelte Zweiphasenströmungen. Grafische Methoden können jedoch die allmählichen Übergänge zwischen Strömungsformen kaum darstellen. Analytische Modelle liefern nur vereinfachte Näherungswerte der Zweiphasenströmung, die noch nicht für sich entwickelnde Rohrströmung qualifiziert wird. In dieser Arbeit wurde eine umfangreiche experimentelle Datenbasis horizontaler Wasser-Luft-Strömungen in zwei Versuchsstrecken mit Rohrinnendurchmessern von D = 50 mm und D = 200 mm und Einlauflängen im Bereich 10 < L/D < 75 erstellt. Auf diese Weise decken die Daten sowohl sich entwickelnde Rohrströmungen mit typischen Einlauflängen für Einspeiseleitungen ab, als auch weiter (in axialer Richtung) entwickelte Strömungen, die mit dem umfangreich untersuchten Referenzsystem Wasser-Luft vergleichbar sind. Die Auswirkung von Rohrbögen auf die Strömungsmorphologie stromauf- und stromabwärts wurde gezielt untersucht. Die Strömungsmorphologie wurde mit bildgebenden Gittersensoren erfasst. Ein 4D-Fuzzy-Algorithmus wurde zur objektiven Identifizierung der Strömungsmorphologien eingesetzt. Auf Grundlage dieser Fuzzy-Darstellung der Strömung wurden die Strömungsmorphologien klassifiziert, und es wurde eine neuartige 2D-Visualisierungstechnik entworfen, mit der die Strömungsentwicklung entlang der Einspeiseleitungen diskutiert wurde. Unerwünschte Strömungsmorphologien (intermittierende Strömung und Tropfenmitriss) während des Betriebs zweiphasiger Einspeisungen sind mit herkömmlichen Auslegungswerkzeugen kaum vorherzusagen. Das Einsetzen intermittierender Strömungen wurde auf Grundlage der experimentellen Daten analysiert. Daraufhin wurden existierende Kriterien, basierend auf den notwendigen Mindestfüllständen, für das Einsetzen intermittierender Strömungen in Abhängigkeit von den untersuchten Einlauflängen angepasst. Die charakteristische Dynamik von Strömungsmorphologien, die Tropfenmittriss hervorrufen, wurde analysiert. Voraussagemethoden zur Vorhersage der Anfälligkeit welliger Strömungen für das Auftreten von Tropfenmitriss wurden auf der Grundlage von Wellenfrequenzen entwickelt und für gerade Einspeiserohre und horizontale 90°-Bögen angewandt. Von den zahlreichen verfügbaren Modellen zur Vorhersage des Gasanteils wurden 66 Modelle reduzierter Ordnung für gerade Einspeiseleitungen und horizontale 90°-Rohrbögen getestet. Davon wurden die für variable Betriebsbedingungen und Rohrgeometrien am besten geeigneten Modelle ermittelt und angepasst. Komplementäre 3D-Simulationen wurden durchgeführt, um die Anwendbarkeit numerischer Codes (VoF, AIAD) für Strömungen mit freien Grenzflächen zu bestätigen. Die Strömungsmorphologien wurden im makroskopischen Maßstab erfolgreich reproduziert, die Simulationsergebnisse bleiben jedoch hinsichtlich ihrer quantitativen Vorhersagekraft hinter den Modellen reduzierter Ordnung zurück.:Abstract II Kurzfassung IV Acknowledgement VI Nomenclature VIII Table of Contents XIII 1 Introduction 1 1.1 Thermal separation in view of the 21st century 1 1.2 Engineering and design of rectification plants 2 1.3 Outline of the thesis 4 2 State of the art 5 2.1 Two-phase feeds in thermal separation 5 2.1.1 Feed condition as adjustable parameter 5 2.1.2 Thermohydraulic optimization 8 2.1.3 Hydrodynamic conditioning 9 2.2 Hydrodynamics of two-phase feeds 11 2.2.1 Flow morphologies in feed pipes 11 2.2.2 Droplet entrainment 14 2.2.3 Flow regime maps 17 2.2.4 Consequences for two-phase feeds 19 2.3 Modelling of two-phase feeds 23 2.3.1 Basic definitions 23 2.3.2 Fundamentals of the two-fluid model 25 2.3.3 The interfacial level gradient 29 2.3.4 Analytical models 32 2.3.5 CFD simulations for commercial feed pipes 34 2.4 Objectives of this thesis 36 3 Experimental method and algorithms for flow characterization 37 3.1 Experimental setups 37 3.2 Wire-mesh sensors 40 3.3 Experimental procedure 42 3.4 Data processing 44 3.4.1 Fuzzy flow morphology classification 45 3.4.2 Power spectral density 48 3.5 Measurement uncertainty 49 4 Flow morphologies in different feed pipe geometries 53 4.1 Developing two-phase flow in straight pipes 53 4.2 Effect of pipe curvatures on the flow morphology 55 4.3 Morphology recovery 57 4.4 Conclusions 60 5 Prediction of undesirable flow morphologies in feed pipes 61 5.1 Initiation of intermittent flows 61 5.2 Onset of droplet entrainment 62 5.2.1 Vulnerable flow morphologies 62 5.2.2 Derivation of a criterion for onset of entrainment 64 5.2.3 Adjustment of the criterion for the investigated pipe geometries 67 5.3 Conclusions 70 6 Reduced-order modelling of two-phase feeds 71 6.1 Prediction of void fraction 71 6.2 Liquid levels 75 6.3 Conclusions 78 7 CFD modelling of two-phase feeds 79 7.1 Simulation setup 79 7.2 Multiphase models 82 7.3 Comparison with experimental data 83 7.3.1 Straight pipes 83 7.3.2 Horizontal 90° bends 85 7.4 Conclusions 88 8 Summary and recommendations for future work 89 8.1 Summary 89 8.2 Recommendations for future work 91 References 94 List of figures 113 List of tables 118 Appendix i Scientific publications and contributions xxxiii Eidesstattliche Erklärung xxxvi