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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sampling procedures for low temperature dynamics on complex energy landscapes

Nemnes, George Alexandru 22 May 2008 (has links) (PDF)
The present work deals with relaxation dynamics on complex energy landscapes. The state space of a complex system possesses, as a hallmark, the multitude of local minima separated by higher states, called barrier states. This feature gives rise to a host of non-equilibrium phenomena. From case to case, for different complex systems, ranging from atomic clusters, spin glasses and proteins to neural networks or financial markets, the key quantities like energy and temperature may have different meanings, though their functionality is the same. The numerical handling of relaxational dynamics in such complex systems, even for relatively small sizes, poses a tough challenge if the entire state space is to be considered. Here, state space sampling procedures are introduced that provide an accurate enough description for the low temperature dynamics, using small subsets from the original state space. As test cases, short range Ising spin systems were considered. The samples - depending on the way they are constructed - provide either lower bounds for the largest relaxation timescales in a quasi-ergodic component of the state space or the isothermal relaxation of the mean energy, like in the proposed DRS method. Upon the latter procedure, a parallel heuristic is built which gives the possibility of handling large samples. The collected structural data provides information of the state space topology in systems with different levels of frustration, like disordered ferromagnets and spin glasses. It provides insights into the focusing/anti-focusing types of landscapes, which give rise to different ground state accessibilities. For the large samples, the domain formation and growth has been analysed and compared with existing experimental and numerical data in literature. The algorithms proposed here become more and more accurate as the temperature is decreased and therefore they can provide an alternative to the classical Monte Carlo approach for this temperature range.
2

Sampling procedures for low temperature dynamics on complex energy landscapes

Nemnes, George Alexandru 21 May 2008 (has links)
The present work deals with relaxation dynamics on complex energy landscapes. The state space of a complex system possesses, as a hallmark, the multitude of local minima separated by higher states, called barrier states. This feature gives rise to a host of non-equilibrium phenomena. From case to case, for different complex systems, ranging from atomic clusters, spin glasses and proteins to neural networks or financial markets, the key quantities like energy and temperature may have different meanings, though their functionality is the same. The numerical handling of relaxational dynamics in such complex systems, even for relatively small sizes, poses a tough challenge if the entire state space is to be considered. Here, state space sampling procedures are introduced that provide an accurate enough description for the low temperature dynamics, using small subsets from the original state space. As test cases, short range Ising spin systems were considered. The samples - depending on the way they are constructed - provide either lower bounds for the largest relaxation timescales in a quasi-ergodic component of the state space or the isothermal relaxation of the mean energy, like in the proposed DRS method. Upon the latter procedure, a parallel heuristic is built which gives the possibility of handling large samples. The collected structural data provides information of the state space topology in systems with different levels of frustration, like disordered ferromagnets and spin glasses. It provides insights into the focusing/anti-focusing types of landscapes, which give rise to different ground state accessibilities. For the large samples, the domain formation and growth has been analysed and compared with existing experimental and numerical data in literature. The algorithms proposed here become more and more accurate as the temperature is decreased and therefore they can provide an alternative to the classical Monte Carlo approach for this temperature range.
3

Der Rotationsmechanismus und die elastische Kopplung der F-ATP-Synthase

Sielaff, Hendrik 08 November 2007 (has links)
Die F-ATP-Synthase nutzt die elektrochemische Differenz des Protons über eine Membran zur Synthese von ATP. Sie setzt sich aus dem katalytisch aktiven F1-Teil und dem membranständigen FO-Teil zusammen. In FO wird durch die protonenmotorische Kraft (pmf) ein Drehmoment erzeugt, das zur Synthese von ATP in den 3 katalytischen Untereinheiten genutzt wird. Mechanisch gesehen besteht das Motorenzym aus einem Rotor, der sich gegen einen Stator dreht. Ein an FO gekoppeltes Actinfilament diente als Reporter für die Orientierung und Biegsamkeit der Rotoruntereinheiten. Das molekulare Koordinatensystem, gewonnen aus der Kristallstruktur der mitochondrialen F-ATP-Synthase, wurde mit den Koordinatensystem des aktiven Enzyms aus E. coli korreliert. Das ATP hydrolysierende Enzym wartet auf die Bindung von ATP, gefolgt von einem 80°-Schritt. Anschließend wird während des katalytischen Wartezustands ATP hydrolysiert, gefolgt von einem 40°-Schritt. Mittels einer Disulfidbrücke zwischen Rotor und Stator wurde das aktive Enzym in einer Orientierung festgehalten, die der Kristallstruktur entspricht. Diese Orientierung stimmt mit der Stellung des aktiven Enzyms sowohl im katalytischen Wartezustand als auch im ADP-inhibierten Zustand überein. In der Kristallstruktur sind 2 katalytische Zentren mit Nukleotiden besetzt. Dagegen sind im aktiven Enzym während der katalytischen Pause alle 3 katalytischen Zentren besetzt. Durch Schließen von Disulfidbrücken zwischen Rotor und Stator wurden die inneren Elastizitätsparameter des inhibierten und elastisch relaxierten Enzyms anhand des Ausschlags des Actinfilaments bestimmt. Der elastisch biegsame Bereich liegt zwischen den Angriffspunkten der thermodynamischen Kräft, d.h. der pmf in FO und dem Phophatpotential in F1. Die Energie des Drehmoments wird in den Rotoruntereinheiten elastisch gespeichert und anschließend für die Synthese von ATP genutzt. Die elastische Kopplung sorgt für eine hohe kinetische Effizienz und eine hohe Umsatzrate.
4

Struktur der Energielandschaft und Relaxation von +/- J Spinglas-Modellen / Structure of energy landscape and relaxation of +/- J spin glass models

Krawczyk, Jaroslaw 10 May 2003 (has links) (PDF)
Die komplizierte Struktur der Energielandschaft wurde am Beispiel des +/- J Spinglas-Modells untersucht. Sie ist in glasartigen Systemen der Schlüssel zum Verständnis einer verlangsamten Dynamik. Es wurde ein enger Zusammenhang zwischen der Dynamik und der Energielandschaft nachgewiesen. Die Energielandschaft wird in +/- J Spinglas Modellsystemen durch Cluster charakterisiert, die infolge ihrer Konnektivität größere Objekte (z.B. Täler) bilden. Einzelne Cluster, aber auch ganze Täler, sind miteinander durch sogenannten Sattelcluster verknüpft. Die physikalischen Eigenschaften werden durch die Strukturen der Verknüpfungen und durch die innere Struktur der Cluster geprägt. Zur Beschreibung der Energielandschaften wurde die genaue Kenntnis der Zustände benutzt. Auf der Grundlage des "branch-and-bound" Verfahrens war es möglich, für kleine Systeme alle Zustände bis zu der dritten Anregung zu bestimmen. Danach wurden die Konfigurationen so sortiert, dass die Beziehungen zwischen ihnen, wie z.B. Nachbarschaften und Clusterzugehörigkeiten, einfach zu finden waren. Es gelang, die exakte Landschaft für Systeme bis L=6 aufzubauen. Für größere Systeme ist es zur Zeit unmöglich, alle niederenergetischen Zustände zu finden. Eine alternative Möglichkeit, die Struktur zu beschreiben, erhält man durch Untersuchung der Verteilung der Overlap. An der Gestalt der Verteilung erkennt man, ob die niederenergetische Struktur kompliziert oder einfach ist. Bei genaueren Untersuchungen ist es sogar möglich, die Anzahl der existierenden Täler abzuschätzen. Die Untersuchungen der Overlap bei 8555 3D Systemen (L=4) weisen darauf hin, dass bei kleineren Grundzustandsenergien die Struktur durch zwei spiegelsymmetrische Täler geprägt ist. Mit wachsender Grundzustandsenergie wird die Struktur der Systeme immer komplizierter. Eine weitere wichtige Komponente der Energielandschaft ist die innere Struktur der Sattelcluster. Ein Sattelcluster besteht aus wenigstens drei Gruppen von Konfigurationen. Zwei Gruppen enthalten Konfigurationen, die mit den Grundzustandsclustern verbunden sind, und die dritte Gruppe verbindet die beiden. Es passiert oft, dass die Konfigurationsgruppen, die verschiedene Grundzustandscluster verbinden, weit voneinander entfernt liegen. Dies wurde als ein wichtiger Aspekt erkannt, der zu einer Verlangsamung dynamischer Prozesse führt. Der andere Aspekt der Energielandschaft ist ihr Zusammenhang mit dem Realraumbild. Das Realraumbild ist als die Lage der Spins auf dem Gitter zu verstehen. Spins kann man zu verschiedenen Spindomänen zusammenfassen, die dann auf natürliche Weise die Struktur der Energielandschaft generieren. Für die Größe der einzelnen Cluster sind die freien Spins verantwortlich. Es wurde bestätigt, dass die Existenz einzelner Täler durch Spindomänen erklärt werden kann. Dabei wird durch das kollektive Umdrehen aller Spins in einer solcher Domäne ein anderer Cluster in einem anderen Tal erzeugt. Neben dem Zusammenhang von Spindomänen und Energielandschaft konnte der Einfluss von bestimmten zusammenhängenden Strukturen freier Spins genauer aufgeklärt werden. Hier ergeben sich Ansatzpunkte für weitergehende Untersuchungen.
5

Struktur der Energielandschaft und Relaxation von +/- J Spinglas-Modellen

Krawczyk, Jaroslaw 28 April 2003 (has links)
Die komplizierte Struktur der Energielandschaft wurde am Beispiel des +/- J Spinglas-Modells untersucht. Sie ist in glasartigen Systemen der Schlüssel zum Verständnis einer verlangsamten Dynamik. Es wurde ein enger Zusammenhang zwischen der Dynamik und der Energielandschaft nachgewiesen. Die Energielandschaft wird in +/- J Spinglas Modellsystemen durch Cluster charakterisiert, die infolge ihrer Konnektivität größere Objekte (z.B. Täler) bilden. Einzelne Cluster, aber auch ganze Täler, sind miteinander durch sogenannten Sattelcluster verknüpft. Die physikalischen Eigenschaften werden durch die Strukturen der Verknüpfungen und durch die innere Struktur der Cluster geprägt. Zur Beschreibung der Energielandschaften wurde die genaue Kenntnis der Zustände benutzt. Auf der Grundlage des "branch-and-bound" Verfahrens war es möglich, für kleine Systeme alle Zustände bis zu der dritten Anregung zu bestimmen. Danach wurden die Konfigurationen so sortiert, dass die Beziehungen zwischen ihnen, wie z.B. Nachbarschaften und Clusterzugehörigkeiten, einfach zu finden waren. Es gelang, die exakte Landschaft für Systeme bis L=6 aufzubauen. Für größere Systeme ist es zur Zeit unmöglich, alle niederenergetischen Zustände zu finden. Eine alternative Möglichkeit, die Struktur zu beschreiben, erhält man durch Untersuchung der Verteilung der Overlap. An der Gestalt der Verteilung erkennt man, ob die niederenergetische Struktur kompliziert oder einfach ist. Bei genaueren Untersuchungen ist es sogar möglich, die Anzahl der existierenden Täler abzuschätzen. Die Untersuchungen der Overlap bei 8555 3D Systemen (L=4) weisen darauf hin, dass bei kleineren Grundzustandsenergien die Struktur durch zwei spiegelsymmetrische Täler geprägt ist. Mit wachsender Grundzustandsenergie wird die Struktur der Systeme immer komplizierter. Eine weitere wichtige Komponente der Energielandschaft ist die innere Struktur der Sattelcluster. Ein Sattelcluster besteht aus wenigstens drei Gruppen von Konfigurationen. Zwei Gruppen enthalten Konfigurationen, die mit den Grundzustandsclustern verbunden sind, und die dritte Gruppe verbindet die beiden. Es passiert oft, dass die Konfigurationsgruppen, die verschiedene Grundzustandscluster verbinden, weit voneinander entfernt liegen. Dies wurde als ein wichtiger Aspekt erkannt, der zu einer Verlangsamung dynamischer Prozesse führt. Der andere Aspekt der Energielandschaft ist ihr Zusammenhang mit dem Realraumbild. Das Realraumbild ist als die Lage der Spins auf dem Gitter zu verstehen. Spins kann man zu verschiedenen Spindomänen zusammenfassen, die dann auf natürliche Weise die Struktur der Energielandschaft generieren. Für die Größe der einzelnen Cluster sind die freien Spins verantwortlich. Es wurde bestätigt, dass die Existenz einzelner Täler durch Spindomänen erklärt werden kann. Dabei wird durch das kollektive Umdrehen aller Spins in einer solcher Domäne ein anderer Cluster in einem anderen Tal erzeugt. Neben dem Zusammenhang von Spindomänen und Energielandschaft konnte der Einfluss von bestimmten zusammenhängenden Strukturen freier Spins genauer aufgeklärt werden. Hier ergeben sich Ansatzpunkte für weitergehende Untersuchungen.
6

Unveiling the double-well energy landscape in a ferroelectric layer

Hoffmann, Michael, Fengler, Franz P. G., Herzig, Melanie, Mittmann, Terence, Max, Benjamin, Schroeder, Uwe, Negrea, Raluca, Lucian, Pinitilie, Slesazeck, Stefan, Mikolajick, Thomas 17 October 2022 (has links)
The properties of ferroelectric materials, which were discovered almost a century ago¹ , have led to a huge range of applications, such as digital information storage² , pyroelectric energy conversion³ and neuromorphic computing⁴⁻⁵ . Recently, it was shown that ferroelectrics can have negative capacitance⁶⁻¹¹, which could improve the energy efficiency of conventional electronics beyond fundamental limits¹²⁻¹⁴. In Landau–Ginzburg–Devonshire theory¹⁵⁻¹⁷, this negative capacitance is directly related to the doublewell shape of the ferroelectric polarization–energy landscape, which was thought for more than 70 years to be inaccessible to experiments¹⁸. Here we report electrical measurements of the intrinsic double-well energy landscape in a thin layer of ferroelectric Hf₀.₅Zr₀.₅O₂. To achieve this, we integrated the ferroelectric into a heterostructure capacitor with a second dielectric layer to prevent immediate screening of polarization charges during switching. These results show that negative capacitance has its origin in the energy barrier in a double-well landscape. Furthermore, we demonstrate that ferroelectric negative capacitance can be fast and hysteresis-free, which is important for prospective applications¹⁹. In addition, the Hf₀.₅Zr₀.₅O₂ used in this work is currently the most industry-relevant ferroelectric material, because both HfO₂ and ZrO₂ thin films are already used in everyday electronics²⁰. This could lead to fast adoption of negative capacitance effects in future products with markedly improved energy efficiency.
7

Investigation of biological macromolecules using atomic force microscope-based techniques

Bippes, Christian Alexander 19 August 2009 (has links) (PDF)
The atomic force microscope (AFM) provides a powerful instrument for investigating and manipulating biological samples down to the subnanometer scale. In contrast to other microscopy methods, AFM does not require labeling, staining, nor fixation of samples and allows the specimen to be fully hydrated in buffer solution during the experiments. Moreover, AFM clearly compares in resolution to other techniques. In general, the AFM can be operated in an imaging or a force spectroscopy mode. In the present work, advantage was taken of this versatility to investigate single biomolecules and biomolecular assemblies. A novel approach to investigate the visco-elastic behavior of biomolecules under force was established, using dextran as an example. While a molecule tethered between a solid support and the cantilever tip was stretched at a constant velocity, the thermally driven oscillation of the cantilever was recorded. Analysis of the cantilever Brownian noise provided information about the visco-elastic properties of dextran that corresponded well to parameters obtained by alternative methods. However, the approach presented here was easier to implement and less time-consuming than previously used methods. A computer controlled force-clamp system was set up, circumventing the need for custom built analogue electronics. A commercial PicoForce AFM was extended by two computers which hosted data acquisition hardware. While the first computer recorded data, the second computer drove the AFM bypassing the manufacturer's microscope control software. To do so, a software-based proportional-integral-differential (PID) controller was implemented on the second computer. It allowed the force applied to a molecule to be held constant over time. After tuning of the PID controller, response times obtained using that force-clamp setup were comparable to those of the recently reported analogue systems. The performance of the setup was demonstrated by force-clamp unfolding of a pentameric Ig25 construct and the membrane protein NhaA. In the latter case, short-lived unfolding intermediates that were populated for less than 10 ms, could be revealed. Conventional single-molecule dynamic force spectroscopy was used to unfold the serine:threonine antiporter SteT from Bacillus subtilis, an integral membrane protein. Unfolding force patterns revealed the unfolding barriers stabilizing structural segments of SteT. Ligand binding did not induce new unfolding barriers suggesting that weak interactions with multiple structural segments were involved. In contrast, ligand binding caused changes in the energy landscape of all structural segments, thus turning the protein from a brittle, rigid into a more stable, structurally flexible conformation. Functionally, rigidity in the ligand-free state was thought to facilitate specific ligand binding, while flexibility and increased stability were required for conformational changes associated with substrate translocation. These results support the working model for transmembrane transport proteins that provide alternate access of the binding site to either face of the membrane. Finally, high-resolution imaging was exploited to visualize the extracellular surface of Cx26 gap junction hemichannels (connexons). AFM topographs reveal pH-dependent structural changes of the extracellular connexon surface in presence of HEPES, an aminosulfonate compound. At low pH (< 6.5), connexons showed a narrow and shallow channel entrance, which represented the closed pore. Increasing pH values resulted in a gradual opening of the pore, which was reflected by increasing channel entrance widths and depths. At pH > 7.6 the pore was fully opened and the pore diameter and depth did not increase further. Importantly, coinciding with pore gating a slight rotation of the subunits was observed. In the absence of aminosulfonate compounds, such as HEPES, acidification did not affect pore diameters and depths, retaining the open state. Thus, the intracellular concentration of taurine, a naturally abundant aminosulfonate compound, might be used to tune gap junction sensitivity at low pH.
8

Investigation of biological macromolecules using atomic force microscope-based techniques

Bippes, Christian Alexander 18 August 2009 (has links)
The atomic force microscope (AFM) provides a powerful instrument for investigating and manipulating biological samples down to the subnanometer scale. In contrast to other microscopy methods, AFM does not require labeling, staining, nor fixation of samples and allows the specimen to be fully hydrated in buffer solution during the experiments. Moreover, AFM clearly compares in resolution to other techniques. In general, the AFM can be operated in an imaging or a force spectroscopy mode. In the present work, advantage was taken of this versatility to investigate single biomolecules and biomolecular assemblies. A novel approach to investigate the visco-elastic behavior of biomolecules under force was established, using dextran as an example. While a molecule tethered between a solid support and the cantilever tip was stretched at a constant velocity, the thermally driven oscillation of the cantilever was recorded. Analysis of the cantilever Brownian noise provided information about the visco-elastic properties of dextran that corresponded well to parameters obtained by alternative methods. However, the approach presented here was easier to implement and less time-consuming than previously used methods. A computer controlled force-clamp system was set up, circumventing the need for custom built analogue electronics. A commercial PicoForce AFM was extended by two computers which hosted data acquisition hardware. While the first computer recorded data, the second computer drove the AFM bypassing the manufacturer's microscope control software. To do so, a software-based proportional-integral-differential (PID) controller was implemented on the second computer. It allowed the force applied to a molecule to be held constant over time. After tuning of the PID controller, response times obtained using that force-clamp setup were comparable to those of the recently reported analogue systems. The performance of the setup was demonstrated by force-clamp unfolding of a pentameric Ig25 construct and the membrane protein NhaA. In the latter case, short-lived unfolding intermediates that were populated for less than 10 ms, could be revealed. Conventional single-molecule dynamic force spectroscopy was used to unfold the serine:threonine antiporter SteT from Bacillus subtilis, an integral membrane protein. Unfolding force patterns revealed the unfolding barriers stabilizing structural segments of SteT. Ligand binding did not induce new unfolding barriers suggesting that weak interactions with multiple structural segments were involved. In contrast, ligand binding caused changes in the energy landscape of all structural segments, thus turning the protein from a brittle, rigid into a more stable, structurally flexible conformation. Functionally, rigidity in the ligand-free state was thought to facilitate specific ligand binding, while flexibility and increased stability were required for conformational changes associated with substrate translocation. These results support the working model for transmembrane transport proteins that provide alternate access of the binding site to either face of the membrane. Finally, high-resolution imaging was exploited to visualize the extracellular surface of Cx26 gap junction hemichannels (connexons). AFM topographs reveal pH-dependent structural changes of the extracellular connexon surface in presence of HEPES, an aminosulfonate compound. At low pH (< 6.5), connexons showed a narrow and shallow channel entrance, which represented the closed pore. Increasing pH values resulted in a gradual opening of the pore, which was reflected by increasing channel entrance widths and depths. At pH > 7.6 the pore was fully opened and the pore diameter and depth did not increase further. Importantly, coinciding with pore gating a slight rotation of the subunits was observed. In the absence of aminosulfonate compounds, such as HEPES, acidification did not affect pore diameters and depths, retaining the open state. Thus, the intracellular concentration of taurine, a naturally abundant aminosulfonate compound, might be used to tune gap junction sensitivity at low pH.
9

Renewable Borders: Sumer School. Across, October 23-27, 2023

Nathanson, Alex, Kullik, Jakob, Capomaggi, Julia, Gawryluk, Dorota, Krawczy, Dorota Anna, Acri, Marco 02 August 2024 (has links)
Electric consumption worldwide is projected to sharply increase in the coming decades, driven by population growth and the electrification of more and more human activities, like transportation, communication, industry, and housing. Electricity is thus becoming central to modern society. Most optimistic forecasts suggest that, by 2050, production will be primarily based on renewable energy sources, with the aim of achieving zero greenhouse gas emissions and reducing dependence on fossil fuels. The construction of the necessary infrastructure for this energy transition, such as solar and wind farms, is shaping significant economic, political, and social transformations, while also deeply influencing landscape quality and territorial configuration. Natural resources like the sun or wind do not recognize political borders, historical boundaries of regions or countries. On the contrary, they introduce a new dimension of a continuous, anonymous geography that blurs the conventional concept of borders. One of the aspects generally emphasised with the installation of solar and wind farms concerns their visual impact, and are emblematic of problems associated with the construction of extensive power plants in natural landscapes. Their construction consumes hundreds of hectares of land and significantly alters the skyline. However, these concerns seem to overshadow a more significant issue: the homogenization of territories as they repeat a single solution across the globe, even when the conditions of the sites are completely different. The technical design is an oversimplification of the problem, resulting in a single technology that is designed and implemented to varied scenarios without adapting to local conditions. The system components of this infrastructure are few in number and completely disregard the previous configuration of the territory and the problems traditionally associated with architecture. The built infrastructure of these plants severs any connection with the landscape and memory, it is devoid of any sense of place that evolved in response to historical development and the particular local idiosyncrasies. Traditional constructions, regardless of their technological development, were based on local techniques and materials, evolving with accrued intergenerational experience, with mutual their territory, technology, and architecture were intrinsically. The new renewable energy infrastructure also represents an unprecedented global imposition without the consensus of the local population, rapidly altering the territory’s configuration in just a few years. This imposition also causes a significant transformation of the traditional concept of borders, “lines” that separate tradition, language, or architectural resolution. In this sense, areas hosting these massive infrastructure often transition from productive tissues of the primary sector at the local level —mainly livestock and agriculture— to predominantly industrial ones that function on a global scale. However, these facilities rarely benefit the local population, as the energy produced is usually consumed hundreds of kilometres away. Furthermore, they operate autonomously, without labour, and are owned by large energy corporations, resulting in the distribution of profits among a few hands far away from the affected territories. These corporations are thus building a geography that is drastically different from what the first power plants of rudimentary technology could create. The new renewable facilities disregard the historical, cultural, social, economic, political, and architectural values rooted in the territory, solely to harness wind and solar energy as inexhaustible natural resources in electricity generation. The global implementation of these plants evokes a sense of loss, as it destroys the previous state formed over centuries. However, their construction offers a valuable opportunity to begin imagining the present transformation of the territory by adopting a multidisciplinary approach. The problem posed by these facilities, as we will see, transcends mere technological development and the foreseeable increase in consumption of resources as the only possible paths to progress. The terms “renewable” and “borders” precisely invite to incorporate other dimensions and disciplines to address this issue in a renewed and cross-cutting manner, forming a complex network through the knowledge provided by politics, landscape, history, art, and architecture. This publication, prepared on the occasion of the international workshop Renewable Borders —held in the German city of Chemnitz in October 2023— aims to offer different approaches to the problem of new renewable facilities and their relationship with border configurations. Can we still consider them as immutable lines destined to endure? How does energy production influence the evolution of these limits? What lexicon do we use to define it? In what ways can we represent them? Far from offering concrete answers, the six essays compiled in this publication pose new questions in an open and exploratory manner, uncovering a new field of inquiry that needs renewed thinking beyond the confines of borders.:10 Beyond borders Carlos Gonzalvo and Julia Capomaggi 14 Frivolous energies Alex Nathanson 18 Critical borders Jakob Kullik 22 Renewable surfaces Julia Capomaggi 40 Energy production in the cityscape Dorota Gawryluk and Dorota Anna Krawczyk 44 Heritage and power Marco Acri 46 Renewable lexicon 51 Students 52 Biographies
10

Renewable Borders: Summer School Across, October 23-27, 2023

Nathanson, Alex, Kullik, Jakob, Gawryluk, Dorota, Krawczy, Dorota Anna, Acri, Marco 09 October 2024 (has links)
Electric consumption worldwide is projected to sharply increase in the coming decades, driven by population growth and the electrification of more and more human activities, like transportation, communication, industry, and housing. Electricity is thus becoming central to modern society. Most optimistic forecasts suggest that, by 2050, production will be primarily based on renewable energy sources, with the aim of achieving zero greenhouse gas emissions and reducing dependence on fossil fuels. The construction of the necessary infrastructure for this energy transition, such as solar and wind farms, is shaping significant economic, political, and social transformations, while also deeply influencing landscape quality and territorial configuration. Natural resources like the sun or wind do not recognize political borders, historical boundaries of regions or countries. On the contrary, they introduce a new dimension of a continuous, anonymous geography that blurs the conventional concept of borders. One of the aspects generally emphasised with the installation of solar and wind farms concerns their visual impact, and are emblematic of problems associated with the construction of extensive power plants in natural landscapes. Their construction consumes hundreds of hectares of land and significantly alters the skyline. However, these concerns seem to overshadow a more significant issue: the homogenization of territories as they repeat a single solution across the globe, even when the conditions of the sites are completely different. The technical design is an oversimplification of the problem, resulting in a single technology that is designed and implemented to varied scenarios without adapting to local conditions. The system components of this infrastructure are few in number and completely disregard the previous configuration of the territory and the problems traditionally associated with architecture. The built infrastructure of these plants severs any connection with the landscape and memory, it is devoid of any sense of place that evolved in response to historical development and the particular local idiosyncrasies. Traditional constructions, regardless of their technological development, were based on local techniques and materials, evolving with accrued intergenerational experience, with mutual their territory, technology, and architecture were intrinsically. The new renewable energy infrastructure also represents an unprecedented global imposition without the consensus of the local population, rapidly altering the territory’s configuration in just a few years. This imposition also causes a significant transformation of the traditional concept of borders, “lines” that separate tradition, language, or architectural resolution. In this sense, areas hosting these massive infrastructure often transition from productive tissues of the primary sector at the local level —mainly livestock and agriculture— to predominantly industrial ones that function on a global scale. However, these facilities rarely benefit the local population, as the energy produced is usually consumed hundreds of kilometres away. Furthermore, they operate autonomously, without labour, and are owned by large energy corporations, resulting in the distribution of profits among a few hands far away from the affected territories. These corporations are thus building a geography that is drastically different from what the first power plants of rudimentary technology could create. The new renewable facilities disregard the historical, cultural, social, economic, political, and architectural values rooted in the territory, solely to harness wind and solar energy as inexhaustible natural resources in electricity generation. The global implementation of these plants evokes a sense of loss, as it destroys the previous state formed over centuries. However, their construction offers a valuable opportunity to begin imagining the present transformation of the territory by adopting a multidisciplinary approach. The problem posed by these facilities, as we will see, transcends mere technological development and the foreseeable increase in consumption of resources as the only possible paths to progress. The terms “renewable” and “borders” precisely invite to incorporate other dimensions and disciplines to address this issue in a renewed and cross-cutting manner, forming a complex network through the knowledge provided by politics, landscape, history, art, and architecture. This publication, prepared on the occasion of the international workshop Renewable Borders —held in the German city of Chemnitz in October 2023— aims to offer different approaches to the problem of new renewable facilities and their relationship with border configurations. Can we still consider them as immutable lines destined to endure? How does energy production influence the evolution of these limits? What lexicon do we use to define it? In what ways can we represent them? Far from offering concrete answers, the six essays compiled in this publication pose new questions in an open and exploratory manner, uncovering a new field of inquiry that needs renewed thinking beyond the confines of borders.:10 Beyond borders Carlos Gonzalvo and Julia Capomaggi 14 Frivolous energies Alex Nathanson 18 Critical borders Jakob Kullik 22 Renewable surfaces Julia Capomaggi 40 Energy production in the cityscape Dorota Gawryluk and Dorota Anna Krawczyk 44 Heritage and power Marco Acri 46 Renewable lexicon 51 Students 52 Biographies

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