The 10 most recently published documents
The thesis concerns a work of urban history intended not to describe the city but rather to interpret it. By doing so, I have interpreted the city by means of the role played by the so-called ‘great property’ in the European city-making process during the last three decades of the 20th century, specifically focused on the concrete case of military properties in Italy. I have also considered the role played by other kinds of great properties, i.e. industries and railway, which previously acted in the production of the built environment in a different way respect to the military one. As all of them have as common denominator the fact of being ‘capital in land’, I analysed great industrial and railway properties in order to extrapolate a methodology which helped me to interpret the relationship between military properties and city-making process in Europe in the late 20th century.
I have analysed the relationship between the capital in land and the city-making process on the ground of the understanding the interrelation between the great property, the urban development, and the agents involved in the urban and territorial planning. Here I have showed that urban planning is not the decisive factor influencing the citymaking process, but instead the power held by the capital in land. I have found that is the great property the trigger of the creation of new ‘areas of centrality’ intended as large areas for consumerism. As far as the role played by great property is concerned, I have also discovered that it has evolved over time. Originally, industrial and railway properties have been regenerated into a wide range of new profit-driven spaces; successively, I have found out that most of the regeneration of military premises aimed to materialise areas of centrality. The way of interpreting this factor has been based on focusing my attention on the military premises in Italy: I have classified their typology when they have been built and, most importantly, when they have been regenerated into new areas of centrality.
Welfare‐state transformation and entrepreneurial urban politics in Western welfare states since the late 1970s have yielded converging trends in the transformation of the dominant Fordist paradigm of social housing in terms of its societal function and institutional and spatial form. In this article I draw from a comparative case study on two cities in Germany to show that the resulting new paradigm is simultaneously shaped by the idiosyncrasies of the country's national housing regime and local housing policies. While German governments have successively limited the societal function of social housing as a legitimate instrument only for addressing exceptional housing crises, local policies on providing and organizing social housing within this framework display significant variation. However, planning and design principles dominating the spatial forms of social housing have been congruent. They may be interpreted as both an expression of the marginalization of social housing within the restructured welfare housing regime and a tool of its implementation according to the logics of entrepreneurial urban politics.
A new large‐field, high‐sensitivity, single‐mirror coincident schlieren optical instrument has been installed at the Bauhaus‐Universität Weimar for the purpose of indoor air research. Its performance is assessed by the non‐intrusive measurement of the thermal plume of a heated manikin. The schlieren system produces excellent qualitative images of the manikin's thermal plume and also quantitative data, especially schlieren velocimetry of the plume's velocity field that is derived from the digital cross‐correlation analysis of a large time sequence of schlieren images. The quantitative results are compared with thermistor and hot‐wire anemometer data obtained at discrete points in the plume. Good agreement is obtained, once the differences between path‐averaged schlieren data and planar anemometry data are reconciled.
The economic losses from earthquakes tend to hit the national economy considerably; therefore, models that are capable of estimating the vulnerability and losses of future earthquakes are highly consequential for emergency planners with the purpose of risk mitigation. This demands a mass prioritization filtering of structures to identify vulnerable buildings for retrofitting purposes. The application of advanced structural analysis on each building to study the earthquake response is impractical due to complex calculations, long computational time, and exorbitant cost. This exhibits the need for a fast, reliable, and rapid method, commonly known as Rapid Visual Screening (RVS). The method serves as a preliminary screening platform, using an optimum number of seismic parameters of the structure and predefined output damage states. In this study, the efficacy of the Machine Learning (ML) application in damage prediction through a Support Vector Machine (SVM) model as the damage classification technique has been investigated. The developed model was trained and examined based on damage data from the 1999 Düzce Earthquake in Turkey, where the building’s data consists of 22 performance modifiers that have been implemented with supervised machine learning.
Ausgehend von der vielfachen Verwertung der bäuerlichen Kleidung durch den Staat während des Sozialismus in Rumänien wird in der Arbeit das ‚Gemacht-Sein‘ von Volkstrachten befragt entlang von im untersuchten Zeitraum wirkenden Diskursen, wie dem Prozess der Modernisierung oder der Hervorhebung nationaler Werte. Die künstlerische Forschung setzt dabei auf Simulacra (Roland Barthes). Ziel war, tradierte Formate der Wissensaufbereitung und -verbreitung zu appropriieren, so auch von Strategien, die auf der Ebene von Bildern und Sprache agieren, um eine Re-Lektüre sowohl von ‚Volkstracht‘ im Sozialismus als auch von ihren Entsprechungen nach 1989 zu ermöglichen.
Das Innovationsmanagement von Medienorganisationen unterliegt derzeit erheblichen Veränderungen: Im veränderten Marktumfeld erweisen sich Flexibilität, schnelle Richtungswechsel und Anpassungsfähigkeit als zentral. Darauf muss auch die Medienmanagement-Forschung reagieren: Um die Agilität der gegenwärtigen Unternehmenspraxis valide zu erforschen, ist eine ebenso agile, adaptive Forschung gefordert. Zu diesem Zweck schlägt der Beitrag eine praxistheoretische Perspektive auf das Innovationsmanagement von Medienorganisationen vor. Empirische Forschungsdesigns, die aus einem solchen Zugriff resultieren, werden sowohl hinsichtlich ihrer methodischen Herausforderungen als auch ihres Forschungsprojektmanagements diskutiert. Der Beitrag greift außerdem neue Möglichkeitsräume des wissenschaftlichen Publizierens, des Universitätsmanagements sowie der Forschungsorganisation auf, die praxistheoretisch gegründete, empirische Innovationsforschung in der Medienwirtschaft einfordert.
Wind effects can be critical for the design of lifelines such as long-span bridges. The existence of a significant number of aerodynamic force models, used to assess the performance of bridges, poses an important question regarding their comparison and validation. This study utilizes a unified set of metrics for a quantitative comparison of time-histories in bridge aerodynamics with a host of characteristics. Accordingly, nine comparison metrics are included to quantify the discrepancies in local and global signal features such as phase, time-varying frequency and magnitude content, probability density, nonstationarity and nonlinearity. Among these, seven metrics available in the literature are introduced after recasting them for time-histories associated with bridge aerodynamics. Two additional metrics are established to overcome the shortcomings of the existing metrics. The performance of the comparison metrics is first assessed using generic signals with prescribed signal features. Subsequently, the metrics are applied to a practical example from bridge aerodynamics to quantify the discrepancies in the aerodynamic forces and response based on numerical and semi-analytical aerodynamic models. In this context, it is demonstrated how a discussion based on the set of comparison metrics presented here can aid a model evaluation by offering deeper insight. The outcome of the study is intended to provide a framework for quantitative comparison and validation of aerodynamic models based on the underlying physics of fluid-structure interaction. Immediate further applications are expected for the comparison of time-histories that are simulated by data-driven approaches.
Material properties play a critical role in durable products manufacturing. Estimation of the precise characteristics in different scales requires complex and expensive experimental measurements. Potentially, computational methods can provide a platform to determine the fundamental properties before the final experiment. Multi-scale computational modeling leads to the modeling of the various time, and length scales include nano, micro, meso, and macro scales. These scales can be modeled separately or in correlation with coarser scales. Depend on the interested scales modeling, the right selection of multi-scale methods leads to reliable results and affordable computational cost. The present dissertation deals with the problems in various length and time scales using computational methods include density functional theory (DFT), molecular mechanics (MM), molecular dynamics (MD), and finite element (FE) methods.
Physical and chemical interactions in lower scales determine the coarser scale properties. Particles interaction modeling and exploring fundamental properties are significant challenges of computational science. Downscale modelings need more computational effort due to a large number of interacted atoms/particles. To deal with this problem and bring up a fine-scale (nano) as a coarse-scale (macro) problem, we extended an atomic-continuum framework. The discrete atomic models solve as a continuum problem using the computationally efficient FE method. MM or force field method based on a set of assumptions approximates a solution on the atomic scale. In this method, atoms and bonds model as a harmonic oscillator with a system of mass and springs. The negative gradient of the potential energy equal to the forces on each atom. In this way, each bond's total potential energy includes bonded, and non-bonded energies are simulated as equivalent structural strain energies. Finally, the chemical nature of the atomic bond is modeled as a piezoelectric beam element that solves by the FE method.
Exploring novel materials with unique properties is a demand for various industrial applications. During the last decade, many two-dimensional (2D) materials have been synthesized and shown outstanding properties. Investigation of the probable defects during the formation/fabrication process and studying their strength under severe service life are the critical tasks to explore performance prospects. We studied various defects include nano crack, notch, and point vacancy (Stone-Wales defect) defects employing MD analysis. Classical MD has been used to simulate a considerable amount of molecules at micro-, and meso- scales. Pristine and defective nanosheet structures considered under the uniaxial tensile loading at various temperatures using open-source LAMMPS codes. The results were visualized with the open-source software of OVITO and VMD.
Quantum based first principle calculations have been conducting at electronic scales and known as the most accurate Ab initio methods. However, they are computationally expensive to apply for large systems. We used density functional theory (DFT) to estimate the mechanical and electrochemical response of the 2D materials. Many-body Schrödinger's equation describes the motion and interactions of the solid-state particles. Solid describes as a system of positive nuclei and negative electrons, all electromagnetically interacting with each other, where the wave function theory describes the quantum state of the set of particles. However, dealing with the 3N coordinates of the electrons, nuclei, and N coordinates of the electrons spin components makes the governing equation unsolvable for just a few interacted atoms. Some assumptions and theories like Born Oppenheimer and Hartree-Fock mean-field and Hohenberg-Kohn theories are needed to treat with this equation. First, Born Oppenheimer approximation reduces it to the only electronic coordinates. Then Kohn and Sham, based on Hartree-Fock and Hohenberg-Kohn theories, assumed an equivalent fictitious non-interacting electrons system as an electron density functional such that their ground state energies are equal to a set of interacting electrons. Exchange-correlation energy functionals are responsible for satisfying the equivalency between both systems. The exact form of the exchange-correlation functional is not known. However, there are widely used methods to derive functionals like local density approximation (LDA), Generalized gradient approximation (GGA), and hybrid functionals (e.g., B3LYP). In our study, DFT performed using VASP codes within the GGA/PBE approximation, and visualization/post-processing of the results realized via open-source software of VESTA.
The extensive DFT calculations are conducted 2D nanomaterials prospects as anode/cathode electrode materials for batteries. Metal-ion batteries' performance strongly depends on the design of novel electrode material. Two-dimensional (2D) materials have developed a remarkable interest in using as an electrode in battery cells due to their excellent properties. Desirable battery energy storage systems (BESS) must satisfy the high energy density, safe operation, and efficient production costs. Batteries have been using in electronic devices and provide a solution to the environmental issues and store the discontinuous energies generated from renewable wind or solar power plants. Therefore, exploring optimal electrode materials can improve storage capacity and charging/discharging rates, leading to the design of advanced batteries.
Our results in multiple scales highlight not only the proposed and employed methods' efficiencies but also promising prospect of recently synthesized nanomaterials and their applications as an anode material. In this way, first, a novel approach developed for the modeling of the 1D nanotube as a continuum piezoelectric beam element. The results converged and matched closely with those from experiments and other more complex models. Then mechanical properties of nanosheets estimated and the failure mechanisms results provide a useful guide for further use in prospect applications. Our results indicated a comprehensive and useful vision concerning the mechanical properties of nanosheets with/without defects. Finally, mechanical and electrochemical properties of the several 2D nanomaterials are explored for the first time—their application performance as an anode material illustrates high potentials in manufacturing super-stretchable and ultrahigh-capacity battery energy storage systems (BESS). Our results exhibited better performance in comparison to the available commercial anode materials.
Wiederkehrende Belastungen, wie sie beispielsweise an Brücken oder Windenergieanlagen auftreten, können innerhalb der Nutzungsdauer solcher Bauwerke bis zu 1.000.000.000 Lastwechsel erreichen. Um das dadurch eintretende Ermüdungsverhalten von Beton zu untersuchen, werden diese zyklischen Beanspruchungen in mechanischen Versuchen mit Prüfzylindern nachgestellt. Damit Versuche mit solch hohen Lastwechselzahlen in akzeptablen Zeitdauern durchgeführt werden können, wird die Belastungsfrequenz erhöht. Als Folge dieser erhöhten Belas-tungsfrequenz erwärmen sich allerdings die Betonprobekörper, was zu einem früheren, unrealistischen Versagenszeitpunkt führen kann, weshalb die Erwärmung begrenzt werden muss. Um die Wärmefreisetzung in der Probe zu untersuchen, wurden Versuche und Simulationen durchgeführt. Im Beitrag wird die analytische und messtechnische Analyse des Wärmeübergangs an erwärmten Betonzylindern vorgestellt. Resultierend daraus wird eine Möglichkeit zur Reduktion der Erwärmung an zyklisch beanspruchten Betonzylindern vorgestellt.
Das Buch greift die enge Verknüpfung von Industrialisierung und
Urbanisierung auf, die in den letzten gut 250 Jahren Europas Städte und ihre Stadtbaugeschichte maßgeblich geprägt hat. Damit stellen sich auch vielfältige Fragen und Aufgaben für die Denkmalpflege.
Die Habilitationsschrift leistet einen Beitrag, um die stadtbaugeschichtlichen und stadtbildprägenden Werte historischer Industriekomplexe zu erkennen und zu erhalten. Wie können wir die industriellen Stadtlandschaften erfassen? Wie gestalten wir Umnutzungen und Konversionen denkmalgerecht und beziehen im Rahmen eines Heritage-Managements Aspekte der nachhaltigen Stadtentwicklung ein?