À la lumière des apports théoriques des sciences et de la philosophie mais également des arts en général et du cinéma en particulier, cette recherche recense et analyse les figures et les dispositifs du vide dans le cadre occidental du septième art à l’aide d’une filmographie variée, allant du cinéma primitif à celui contemporain et incluant des oeuvres narratives comme expérimentales. Le vide représenté est ainsi abordé sous sa forme spatiale, temporelle, plastique mais également sonore. La seconde partie dédiée au vide-dispositif ausculte, quant à elle, la dimension disséminée, intervallaire mais également absolue du vide propres au dispositif cinématographique. Figures et dispositifs sont par la suite examinés dans le cadre de la relation étroite qui les unit au trauma et sa représentation, fréquemment catalyseur d’une esthétique du vide au cinéma. L’analyse d’objets filmiques en lien avec des évènements historiques tragiques – du génocide arménien à la Première Guerre mondiale en passant par l’examen approfondi des attentats du 11 septembre permet ainsi d’identifier la nature fondamentalement non-symbolique du trauma comme origine causale de cette corrélation. Agissant comme révélateur de cette béance représentationnelle, il épouserait de surcroît un rôle bien souvent défensif comparable à celui caractéristique du bouclier perséen, opérant à la manière d’un pare-excitation plastique dans la but de protéger le spectateur de l’image pétrifiante. Ce constat également éprouvé hors du cadre traumatique de nature uniquement historique dans lequel ont été plus spécifiquement conduites ces recherches pousse aujourd’hui à envisager la possibilité d’une relation plus vaste (et notamment plus universelle que celle occidentale à laquelle ce travail s’est restreint) entre la représentation du trauma en général - historique ou fictif, collectif ou personnel – et le vide au cinéma. / According to the scientific and philosophical enlightenments, but also from those of the Arts and especially from cinema, this research analyzes and takes an inventory of the figures and dispositifs of the void in the Occidental frame of the seventh Art, with the help of a varied filmography, from primitive to contemporary cinema, and including narrative and experimental works. The represented void is thus approached under its spatial, temporal, plastic and also sonorous aspect. The second part dedicated studies the disseminated, the interstitial but also the absolute dimension of the void proper to the cinematographic dispositif. Figures and dispositifs of the void are then examined in the light of their close relation to trauma and its representation, which is frequently a catalyst of the void. The study of films related to tragic historical events - from the Armenian genocide to World War One, or the detailed examination of the attacks of September 11 - therefore allows to identify the fundamentally non-symbolic aspect of trauma, as a causal origin of this correlation. Indeed, the void would often adopt a defensive role, similar to the characteristic Persea's shield, acting as a plastic stimulus barrier in order to protect the viewer from the petrifying vision. This proven assessment, out of the traumatic frame of historical nature in which those researches have been made, leads today to considering the possibility of a more vast relation - and especially more universal than the Occidental one to which this work is restricted - between the representation of trauma in general - historical or fictive, collective or personal - and the void in cinema.

abstract: Miniaturization of microdevices comes at the cost of increased circuit complexity and operating current densities. At high current densities, the resulting electron wind imparts a large momentum to metal ions triggering electromigration which leads to degradation of interconnects and solder, ultimately resulting in circuit failure. Although electromigration-induced defects in electronic materials can manifest in several forms, the formation of voids is a common occurrence. This research aims at understanding the morphological evolution of voids under electromigration by formulating a diffuse interface approach that accounts for anisotropic mobility in the metallic interconnect. Based on an extensive parametric study, this study reports the conditions under which pancaking of voids or the novel void ‘swimming’ regimes are observed. Finally, inferences are drawn to formulate strategies using which the reliability of interconnects can be improved. / Dissertation/Thesis / Masters Thesis Materials Science and Engineering 2020

The population and formation of dwarf galaxies, Mr > −14, contain clues about the nature of dark matter. The best place to search for these dwarf galaxies without influence from nearby large galaxies is within galaxy voids, where no galaxies have yet been found. To search for this potential dwarf galaxy population we have developed and applied a new photometric technique. We use three redshifted Ha filters, designated Ha8, Ha12, and Ha16, along with the Sloan broadband filters, g', r', and i' to identify emission line galaxies. From the ratio of the object flux through the Ha filters, Ha12-Ha8 and Ha12-Ha16, we are able to determine the distance to these galaxies and the strength of the emission line captured in the filter set. One problem with using just the three Ha filters is that the system will be sensitive to any emission line which has been redshifted enough to fall within the set. Of particular concern are the [OII] and [OIII] lines which will contaminate the sample. To overcome this we use a color-color relation, g' - r' and r' - i', to help separate which type of emission has been detected. We have applied this method to search for galaxies within the void FN2 and FN8. From this we have found 23 candidate objects which could have Ha emission placing them inside of the void. To better understand the population density dwarf galaxies through voids we have also modeled the population of objects which we will detect having Ha emission compared to the contamination of back ground objects which we can then use to compare the density in the void with the mean galaxy density. We have also begun taking spectra of the emission objects, to ensure our method does detect emission line objects, to test how well the distance and emission strength determination is, and to begin identifying which type of emission we have detected. To date we have taken spectra on 6 objects. All 6 showed emission, 4 with [OII] and 2 with [OIII]. Though none was Ha we formed a “pseudo-redshift” to determine the accuracy of our measurements. This shows that our method is accurate to -127+-204 km/sec.

I CREATED A SCULPTURE, WHICH IS A MATERIALISATION OF A DIGITAL MISTAKE, THAT IS CALLED DATAMOSH. FOR THE CREATION I USED CURRENT 3D TECHNOLOGIES. THE RESULT IS A SCULPTURE MADE OF PLASTER, POLYSTYRENE AND WOOD.

The works aimed at the further development and validation of models for CFD codes. For this reason, the new thermal-hydraulic test facility TOPFLOW was erected and equipped with wire-mesh sensors with high spatial and time resolution. Vertical test sections with nominal diameters of DN50 and DN200 operating with air-water as well as steam-water two-phase flows provided results on the evaluation of flow patterns, on the be¬haviour of the interfacial area as well as on interfacial momentum and heat transfer. The validation of the CFD-code for complex geometries was carried out using 3D void fraction and velocity distributions obtained in an experiment with an asymmetric obstacle in the large DN200 test section. With respect to free surface flows, stratified co- and counter-current flows as well as slug flows were studied in two horizontal test channels made from acrylic glass. Post-test calculations of these experiments succeeded in predicting the slug formation process. Corresponding to the main goal of the project, the experimental data was used for the model development. For vertical flows, the emphasis was put on lateral bubble forces (e.g. lift force). Different constitutive laws were tested using a Multi Bubble Size Class Test Solver that has been developed for this purpose. Basing on the results a generalized inhomogeneous Multiple Size Group (MUSIG) Model has been proposed and implemented into the CFD code CFX (ANSYS). Validation calculations with the new code resulted in the conclusion that particularly the models for bubble coalescence and fragmentation need further optimisation. Studies of single effects, like the assessment of turbulent dissipation in a bubbly flow and the analysis of trajectories of single bubbles near the wall, supplied other important results of the project.

Ziel der Arbeiten war die Weiterentwicklung und Validierung von Modellen in CFD-Codes. Hierzu wurde am FZD die thermohydraulische Versuchsanlage TOPFLOW aufgebaut und mit räumlich und zeitlich hochauflösenden Gittersensoren ausgestattet. Vertikale Teststrecken mit Nenndurchmessern von DN50 bzw. DN200 für Luft/Wasser- sowie Dampf/Wasser-Strömungen lieferten Ergebnisse zur Entwicklung von Strömungsformen, zum Verhalten der Zwischenphasengrenzfläche sowie zum Wärme- und Impulsaustausch zwischen den Phasen. Die Validierung des CFD-Codes in komplexen Geometrien erfolgte anhand von 3D Gasgehalts- und Geschwindigkeitsfeldern, die bei Umströmung eines asymmetrischen Hindernisses auftreten, das in der Teststrecke DN200 eingebaut war. Im Hinblick auf Strömungen mit freier Oberfläche untersuchte das FZD in zwei horizontalen Acrylglas-Kanälen geschichtete Zweiphasenströmungen im Gleich- bzw. Gegenstrom sowie Schwallströmungen. Bei den Nachrechnungen dieser Versuche gelang die Simulation der Schwallentstehung. Entsprechend des Projektziels wurden die experimentellen Ergebnisse zur Modellentwicklung genutzt. Bei vertikalen Strömungen stand die Wirkung der lateralen Blasenkräfte (z.B. Liftkraft) im Vordergrund. Zum Test unterschiedlicher Modellansätze wurde hierzu ein Mehrblasenklassen-Testsolver entwickelt und genutzt. Darauf aufbauend wurde ein neues Konzept für ein Mehrblasenklassenmodell, das Inhomogene MUSIG Modell erarbeitet und in den kommerziellen CFD Code CFX (ANSYS) implementiert. Bei Validierungsrechnungen zeigte sich, dass vor allem die Blasenkoaleszenz- und -zerfallsmodelle weiter optimiert werden müssen. Untersuchungen zu Einzeleffekten, wie z.B. die Abschätzung von Turbulenzkoeffizienten und die Analyse der Trajektoren von Einzelblasen in unmittelbarer Wandnähe, lieferten weitere wichtige Ergebnisse des Projekts.

Die in diesem Bericht vorgestellten Experimente betreffen die Kondensation von Dampf in horizontalen bzw. leicht geneigten Rohren bei hohen auftretenden Temperaturdifferenzen bis zu über 200 K. Weitere Besonderheiten sind die detaillierte Untersuchung des transienten Verhaltens eines nichtkondensierbaren Gases mit einer neuartigen Messtechnik sowie die Ermittlung des Einflusses des Gases auf den Kondensationsvorgang. Beim Experiment wurden schnelle Übergangsvorgänge ausgelöst, indem ein in einer Kühlwanne liegendes, leicht geneigtes Wärmeübertragerrohr plötzlich mit dem Dampfraum eines unter Druck stehenden Kessels verbunden wurde. Dabei wurden im Rohr unterschiedliche Anfangsbedingungen hinsichtlich der Vorlage von nichtkondensierbaren Gasen (in diesem Falle Luft) eingestellt. Es wurden Versuche mit Atmosphärendruck, mit erhöhtem Druck, aber auch mit vorheriger Evakuierung des Versuchsrohrs durchgeführt. Durch eine Instrumentierung mit neuartigen Nadelsonden, die eine Phasendetektion kombiniert mit einer schnellen lokalen Temperaturmessung ermöglichen, konnte die Umverteilung von Dampf, Kondensat und nichtkondensierbarem Gas als Funktion der Zeit beobachtet werden. Damit bieten die erhaltenen Daten die Möglichkeit, insbesondere die in den Thermohydraulikprogrammen vorhandenen Optionen zur Berechnung der Ausbreitung von nichtkondensierbaren Gasen unter transienten Bedingungen zu validieren.

Under hösten 2013 offentliggjorde den svenska regeringen att man vill investera i att bygga ut Stockholms tunnelbana. Denna utbyggnad innefattar nio nya stationer, Sofia på Södermalm är en av dessa stationer. På grund av platsens förutsättningar kommer stationen bli en av de djupaste i världen. Detta förslag utnyttjar dessa förutsättningar för att sammankoppla gatunivån med den underjordiska perrongen och ger den vardagliga upplevelsen av rymd, atmosfär, ljus och tomrum en central position. Förslaget innefattar ett hundra meter djupt schakt, två hisschakt, ett publikt torg park och tunnelbaneperrong. / During the autumn of 2013 the Swedish government announced that they intend to invest in expanding the Stockholm Metro. The expansion includes nine new stations; Sofia on Södermalm is one of them. The conditions of the site make the station to one of the deepest in the world. This proposal makes use of these conditions to connect the street level and the underground platform level and give the everyday experience of space, atmosphere, light and void a central position. The proposal comprises a hundred meters deep shaft, two elevator shafts, a public square park and train platform.

In recent years, the increasingly precise constraints on the value of the Hubble constant, H0, have highlighted a discrepancy between the results arising from early-time and late-time measurements. A potential solution to this so-called Hubble tension is the hypothesis that we reside in a cosmic void, i.e. an underdense cosmic neighbourhood characterized by a faster local expansion rate. In this thesis, we model this scenario through the Lemaître-Tolman-Bondi formalism for an isotropic but inhomogeneous universe containing matter, curvature and a cosmological constant, which we denote by ΛLTB. We numerically implement this framework with two different formulations for the local matter density profile, respectively based upon a more realistic Gaussian ansatz and the idealized scenario of the so-called Oppenheimer-Snyder model. We then constrain the background cosmology and the void parameters involved in each case through a Markov Chain Monte Carlo analysis with a combination of recent data sets: the Pantheon Sample of type Ia supernovae, a collection of baryon acoustic oscillations data points from different galaxy surveys and the distance priors extracted from the latest Planck data release. For both models, the resulting bounds on the investigated parameter space suggest a preference for a -13% density drop with a size of approximately 300 Mpc, interestingly matching the prediction for the so-called KBC void already identified on the basis of independent analyses using galaxy distributions. We quantify the level of improvement on the Hubble tension by analyzing the ΛLTB constraints on the B-band absolute magnitude of the supernovae, which provides the calibration for the local measurements of H0. Since no significant difference is observed with respect to an analogous fit performed with the standard ΛCDM model, we conclude that the potential presence of a local void does not resolve the tension.

Nuclear power plants rely on the Emergency Core Cooling System (ECCS) to cool down the reactor core in case of an accident. Occasionally, air is entrained into the suction piping of ECCS causing voids that decrease pumping efficiency, and consequently damage the pumps. In an attempt to minimize the amount of voids entering the suction side of the pump in ECCS, a Void Recirculation System (VRS) experiment was conducted for a proof of concept purpose. While many studies have been oriented in studying two-component flow behavior in ECCS, none of them propose a solution to minimize air entrainment. As a consequence, there are no simulation models that use computational fluid dynamics to address gas entrainment solutions in ECCS. The objectives of this thesis are to (1) simulate and investigate two-component air-water flow in a VRS that minimizes the amount of air in piping systems, using RELAP5/MOD3 as the computational tool, and (2) to validate the numerical results with respect to experimental results and observations. A one-dimensional model of the VRS was built in RELAP5, in which eight different scenarios (replicating those from the VRS experiment) were simulated for a period of 150 seconds. Four Froude numbers of 0.8, 1.0, 1.3 and 1.6 were evaluated in two different pipe configurations, and the experimental data obtained from the VRS experiment was used to validate the numerical results obtained from these simulations. It was concluded that air recirculation occurs indefinitely throughout the entire 150 seconds of the simulation for Froude numbers up to 1.3; while for a Froude number of 1.6, air recirculation occurs for approximately 100 seconds and ceases after 125 seconds of the simulation. An average air reduction effectiveness of 90% was found for all simulation scenarios. The VRS model was successfully validated and can be used to investigate the effects of air entrainment in suction piping.