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OPEN FAU

Online publication system of Friedrich-Alexander-Universität Erlangen-Nürnberg

The online publication system OPEN FAU is the central publication platform for Open Access publishing for all members of Friedrich-Alexander-Universität. Qualified works from research and teaching may be published here free of charge, either as a primary or secondary publication. The full texts are permanently available worldwide and are findable and citable via catalogues and search engines.


To search for documents in OPEN FAU, please select "Search" (via the magnifying glass at the top right); this will provide you with various search options. If you want to publish a document, go to "Login" and "My Publications". Then drag you document into the field provided and enter the metadata. In just a few steps, you can submit your document. Please note our guidelines, the publication contract and FAQs.

 

Recent Submissions

Book part
Open Access
Self-organization of Nonlinear Networks and Applications to Information Processing
(Manchester University Press, 1991) Pöschel, Thorsten; Ebeling, Werner; Boseniuk, Thorsten; Holden, Arun V.; Kryukov, Vitaly I.
The Hopfield Associative Memory (AM) can be understood as an extremely simple Error Backpropagation Network (EBN). This feature we use for the initialisation of the synaptic matrix. Motivated by findings of neural physiology we further consider networks of artificial neurons with multiplicative couplings. Two proposals for the self-organisation of the network architecture are given in the third section.
Book part
Open Access
Simulation of Network Machines
(Akademie-Verlag, 1989) Pöschel, Thorsten; Ebeling, Werner; Peschel, Manfred
Doctoral thesis
Open Access
Stadtgespräch... Das Szene-Graffiti als Kommunikationsmittel des Urbanen - eine konversationsanalytische Untersuchung anhand einer Graffitistudie in Nürnberg
(2024) Epple, Ulrike; Habermann, Mechthild
Ulrike Epple untersucht die Kommunikationsstrukturen des Szene-Graffitis, die sich als Zeichen des menschlichen Strebens nach Sichtbarkeit, Handlungsfähigkeit, also Autonomie und Erinnerbarkeit lesen lassen. Das Szene-Graffiti wird dabei in den Kontext von Typographieforschung, Poetik, Soziolinguistik und Linguistic Landscape-Forschung gestellt. Durch Epples diachrone Studie gelingt ihr ein orginärer Blick auf das Kommunikationsmittel, der das Fluide der Kommunikation zwischen den Szene-Graffitis auf der Zeitachse fokussiert. Anhand dieser Dynamik wird mit Epples Arbeit eine konversationsanalytische und ethnomethodologische Studie zu Szene-Graffitis an ausgewählten Orten Nürnbergs vorgelegt.
Doctoral thesis
Open Access
Sterically Encumbering Tris(aryloxide)- and Cyclopentadienyl-Supported Uranium Complexes and Their Reactivity
(2024) Löffler, Sascha; Meyer, Karsten
The abundance of depleted uranium as a waste product of the enrichment process and the relatively high abundance of natural uranium makes it a considerable object of research. Any contribution of fundamental research in uranium (coordination) chemistry helps to understand the unique physicochemical properties and reactivity of the metal and its complexes. This lays the foundation for any beneficial use and application of the uranium complexes in the future. The present thesis consists of four chapters that correlate to four publications. Three chapters (3.2, 3.4, and 3.5) include uranium complexes stabilized by tris(aryloxide) ligands and their reactivity and interactions with the (small) molecules methylcyclohexane, methylene chloride, silver fluoride, water, nitrous oxide, and 9,10-diphenylanthracene-9,10-endoperoxide. Chapter 3.3 focusses on uranium complexes with cyclopentadienyl ligands and their molecular and electronic structures. In chapter 3.2, the intermolecular forces behind a uranium–alkane adduct formation are discussed. This study follows up on a publication in JACS 2003 that reports an alkane coordination to the uranium center of the complex [UIII((Ot-Bu,t-BuAr)3tacn)]. To gain insight into the forces behind the adduct formation, the adduct was resynthesized and subsequently analyzed and characterized by X-ray diffraction measurements at 6 K and a variety of spectroscopic methods. The experimental results served as a benchmark to adjust the theoretical methods and calculations that were used to describe the interactions between the uranium and the alkane. Chapter 3.3 includes bent and linear uranium pentabenzyl cyclopentadienyl complexes. It is shown that the electronic structure changes significantly when going from bent to linear. For this purpose, several bent and linear complexes were synthesized and thoroughly characterized by 1H NMR spectroscopy, CHN elemental analysis, UV/Vis/NIR spectroscopy, and SQUID magnetization measurements. The spectroscopic findings were supported and explained by theoretical studies. Chapter 3.4 deals with the activation of small molecules, such as methylene chloride, silver fluoride, water, and nitrous oxide. The primary focus is on the synthesis of a uranium(IV/V/VI) oxide and a uranium(IV/V) hydroxide series. All complexes are stabilized by the same cyclen-based tris(aryloxide) ligand. This allows for an unprecedented comparison of the oxide and hydroxide complexes, which aids drawing conclusions about the physicochemical properties of the uranium complexes. For this purpose, all compounds were extensively characterized by 1H NMR spectroscopy, CHN elemental analysis, UV/Vis/NIR spectroscopy, IR spectroscopy, cyclic voltammetry, and SQUID magnetization measurements. Chapter 3.5 describes a rare uranium-mediated peroxide activation of 9,10-diphenylanthracene-9,10-endoperoxide. The resulting uranium bis(alkoxide) complex was subsequently reduced to serve as a precursor for the formation of a uranyl complex via photochemical release of diphenyl anthracene. Theoretical calculations indicate that the synthesis of the uranyl complex proceeds through an elusive uranium cis-dioxo intermediate.
Doctoral thesis
Open Access
Optimal Design of Communication Systems Based on Wireless Power Transfer with Non-linear Energy Harvesting
(2024) Shanin, Nikita; Schober, Robert; Cottatellucci, Laura
The growth of the number of low-power Internet-of-Things (IoT) devices, such as wireless sensors and wearable medical devices, has recently fuelled interest in the design of small-scale dense IoT communication networks. Despite the notable progress in the development and optimization of these networks, efficient recharging of batteries of small low-power IoT devices still remains an unsolved problem. Since radio frequency (RF) signals are capable of transferring not only information, but also power, wireless power transfer (WPT) constitutes a promising solution to this problem. In this dissertation, we investigate the optimal transmit energy signal design and resource allocation for WPT-based gigahertz (GHz)- and terahertz (THz)-band wireless communication networks. First, we present the electrical circuits, which are typically utilized to harvest power from the received RF signals at user devices, and show that they exhibit a non-linear behaviour. Then, in contrast to other works on the design of WPT-based networks, we accurately take into account the non-linearities of practical energy harvesting (EH) circuits and we optimally design RF GHz-band multi-user WPT systems, wireless powered communication networks (WPCNs), and simultaneous wireless information and power transfer (SWIPT) systems. Furthermore, we also study the tradeoff between the achievable rate and average harvested power in single-user THz SWIPT systems.