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Driven by shorter innovation and product life cycles as well as economic volatility, the demand for reconfiguration of production systems is increasing. Thus, a systematic literature review on reconfiguration management in manufacturing is conducted within this work in order to determine by which degree this is addressed by the literature. To approach this, a definition of reconfiguration management is provided and key aspects of reconfigurable manufacturing systems as well as shortcomings of today’s manufacturing systems reconfiguration are depicted. These provide the basis to derive the requirements for answering the formulated research question. Consequently, the methodical procedure of the literature review is outlined, which is based on the assessment of the derived requirements. Finally, the obtained results are provided and noteworthy insights are given.

Die Produktion von Wasserstoff und Folgeprodukten unter Nutzung erneuerbarer Energien gilt als großer Hoffnungsträger für das Erreichen einer Klimaneutralität. Im Rahmen des Leitprojekts H2Mare soll der Betrieb einer Offshore-Plattform für Power-to-X-Produktionsprozesse erforscht und erprobt werden. Im vorliegenden Beitrag wird zunächst das Projektkonzept einer modularen Offshore-Plattform skizziert. Anschließend werden mit dem Digitalen Zwilling und dem System zur optimalen Betriebsführung zwei Forschungsansätze präsentiert, die zur Effizienzsteigerung dieser Produktionsprozesse beitragen sollen.

Recurrent neural networks and exceedingly Long short-term memory (LSTM) have been investigated intensively in recent years due to their ability to model and predict nonlinear time-variant system dynamics. The present paper delivers a comprehensive overview of existing LSTM cell derivatives and network architectures for time series prediction. A categorization in LSTM with optimized cell state representations and LSTM with interacting cell states is proposed. The investigated approaches are evaluated against defined requirements being relevant for an accurate time series prediction. These include short-term and long-term memory behavior, the ability for multimodal and multi-step ahead predictions and the according error propagation. Sequence-to-sequence networks with partially conditioning outperform the other approaches, such as bidirectional or associative networks, and are best suited to fulfill the requirements.

Autonomous systems are increasingly discussed in the domain of industrial automation. However, there is no consensus in the literature about the definition of industrial autonomous systems, what characteristics do they possess and how to distinguish them from intelligent industrial automation systems. Another important aspect is the comparison between the degree of automation and autonomy. Addressing this confusion, this paper starts with an analysis of the historical development of the term autonomy. Based on the similarities in the definitions, that were identified in a literature review, a comprehensive definition of industrial autonomous systems is presented, and four main characteristics of an industrial autonomous system are derived. Consequently, the characteristics for the realization of an industrial autonomous system (1) systematic process execution, (2) adaptability, (3) self-governance and (4) self-containedness are described in detail. Another objective of this contribution is to assist the developers of industrial autonomous systems to take the above-mentioned characteristics into account. Furthermore, the developer is advised which abilities can be used to achieve the corresponding essential characteristics of industrial autonomous systems. To illustrate the characteristics and abilities of an industrial autonomous system, this paper gives a detailed description of three realized cases of application in industry.

The frequency of changes in production requirements is continuously increasing due to economic volatility, shorter innovation cycles and product life cycles. Therefore, a prediction of all goals of a production system at development time is impossible, which is leading to an increased reconfiguration demand during operation. Currently, there are still some weaknesses concerning the reconfiguration of production systems, which are highlighted in this article. The future of industrial automation will be dominated by Cyber-Physical Production Systems, which offer many promising potentials. Hence, this contribution discusses the Cyber-Physical Production Systems and some of their potentials regarding the reconfiguration issues. Corresponding concepts are required to utilize these theoretical potentials. Therefore, this research provides a basic concept for self-organized reconfiguration management.

Shorter product life cycles and increasing individualization of production leads to an increased reconfiguration demand in the domain of industrial automation systems, which will be dominated by cyber-physical production systems in the future. In constantly changing systems, however, not all configuration alternatives of the almost infinite state space are fully understood. Thus, certain configurations can lead to process instability, a reduction in quality or machine failures. Therefore, this paper presents an approach that enhances an intelligent Digital Twin with a self-organized reconfiguration management based on adaptive process models in order to find optimized configurations more comprehensively., Comment: 6 pages, 2 figures. Submitted to 54th CIRP Conference on Manufacturing Systems 2021

The ecological dimension of literature has found proper attention only in the late 20th century, with the rise of ecocriticism as a new direction of literary studies. Ecocriticism emerged from a revalorization of nature writing in the United States and initially understood itself as a countermovement to the linguistic turn in literary and cultural studies. Since the early 21st century, the scope of ecocritical studies has widened to include literary texts and genres across different periods and cultures. Against the background of the global environmental crisis, it has made a strong case for the contribution of literature, art, and the aesthetic to the critique of anthropocentric master narratives as well as to the imaginative exploration of sustainable alternatives to the historically deranged human–nature relationship. Ecocritical scholars have examined the ecological potential of texts in various periods and literary cultures that make up American literature. They have given particular attention to the Indigenous poetic and storytelling modes of Native Americans, the Romantic and transcendentalist movements of the mid-19th century, the aesthetic practices of modernism and postmodernism, the ethnic diversification of American literature since the late 20th century, and, most obviously, contemporary writing that explicitly defines itself as a critical and creative response to the Anthropocene. Thus, an ecological awareness in American literature emerged in different forms and stages that correspond to major periods, styles, and cultures of literary writing. While it is impossible to do justice to all relevant developments, the rich archive of ecological thought and perception in American literature can be productively brought into the transdisciplinary dialogue of the environmental sciences and humanities. The value of literary texts in relation to other forms of environmental knowledge lies not just in the topics they address but in distinctive aesthetic features, such as embodied multiperspectivity, empathetic imagination, reconnection of cultural to natural ecosystems, polysemic openness, and participatory inclusion of the reader in the transformative experience offered by the texts.

The elements and the elemental have emerged as increasingly productive concepts at the intersection of media theory, ecocriticism, and environmental philosophy. The article builds on this scholarship to discuss the potentials of an elemental approach in literary and cultural studies. Against the backdrop of the climate crisis, it outlines the stakes of an elemental aesthetics capable of interrelating modes of sensory, epistemological, and artistic mediation of ecological relations. As a signifier of animated environments, specific material substances, figurative notions of place, and enabling infrastructures, the elements are key for understanding agency as always already compositional, situated, and distributed. Exploring methodologies of elemental analysis with a focus on American literature and culture, the article concludes by illustrating how an aesthetically grounded conceptualization of agency as elemental is particularly useful for addressing the politics of exposure, emplacement, and extraction in the Anthropocene.

Frontiers in Materials 8, 793120 (2022). doi:10.3389/fmats.2021.793120, The local lattice strain evolution during electrochemical hydrogen charging and mechanical loading in 25Cr-7Ni super duplex stainless steel were measured in-situ using synchrotron high-energy x-ray diffraction. Post-mortem electron backscattered diffraction analysis showed that the austenite phase underwent plastic deformation in the near-surface due to hydrogen-enhanced localized plasticity, where the ferrite phase experienced hardening. In bulk regions, the ferrite was the softer phase, and the austenite remained stiff. Digital image correlation of micrographs recorded, in-situ, during mechanical tensile testing revealed intensified plastic strain localization in the austenite phase, which eventually led to crack initiation. The absorption of hydrogen caused strain localization to occur primarily in austenite grains., Published by Frontiers Media, Lausanne

Journal of alloys and compounds 901, 163616 (2022). doi:10.1016/j.jallcom.2022.163616, Nanocrystalline materials are well known for their beneficial mechanical and physical properties. However, it is of utmost importance to stabilize the microstructure at elevated temperatures to broaden the window of application e.g. by pinning grain boundaries through impurities or oxides. CuCo alloys, severe plastically deformed using high-pressure torsion, were used to investigate the evolution of oxides upon annealing. These investigations were performed using electron microscopy, synchrotron high-energy X-ray scattering and atom probe tomography. Monitoring the evolution of oxides by in-situ small angle scattering investigations indicates the growth of primary oxides as well as the formation of another species of oxide at elevated temperatures. Slightly different coarsening can be observed in heat-treated samples, which can be traced back to the influence of different oxide amounts. The initially supersaturated CuCo matrix changes by the decomposition process as well as Co- and Cu-based oxides formation and growth. It has been found that the major number of oxides which are present after annealing, can already be found in the starting materials., Published by Elsevier, Lausanne

A nanocrystalline CrMnFeCoNi high-entropy alloy produced using severe plastic deformation using high-pressure torsion was annealed at selected temperatures and times (450 °C for 1 h and 15 h and at 600 °C for 1 h), causing a phase decomposition into a multi-phase structure. The samples were subsequently deformed again by high-pressure torsion to investigate the possibility of tailoring a favorable composite architecture by re-distributing, fragmenting, or partially dissolving the additional intermetallic phases. While the second phase in the 450 °C annealing states had high stability against mechanical mixing, a partial dissolution could be achieved in the samples subjected to 600 °C for 1 h.

The capabilities of a cyber-physical production system are determined by their physical and virtual elements and their interaction. The interaction between virtual and physical entities must be precisely defined, and it is therefore necessary to develop capability models and requirements that enable self-reconfiguration of different elements and their relationships. Furthermore, an ultra-flexible production system requires communication and analysis of huge amounts of data as well as flexible, near-real-time communication between elements. This paper discusses and describes the functional and technical requirements of an ultra-flexible factory and presents an approach to the semantic structuring of elements and capabilities.

Active anodes which are operating in highly stable protic media such as 1,1,1,3,3,3-hexafluoroisopropanol are rare. Nickel forms, within this unique solvent, a non-sacrificial active anode at constant current conditions, which is superior to the reported powerful molybdenum system. The reactivity for dehydrogenative coupling reactions of this novel active anode increases when the electrolyte is not stirred during electrolysis. Besides the aryl-aryl coupling, a dehydrogenative arylation reaction of benzylic nitriles was found while stirring the mixture providing quick access to synthetically useful building blocks.

Zusammenfassung Durch zunehmende Agilität im Entwicklungsprozess, kürzere Lebenszyklen und sich ändernde Kunden- und Gesetzgeberanforderungen müssen Produktionssysteme wandlungsfähig sein. Aber jede Veränderung des Systemverhaltens muss anschließend auch erneut abgesichert werden. Zur Absicherung sicherheitskritischer Funktionen eignen sich formale Verifikationsmethoden. Allerdings ist hierzu ein hoher Modellierungsaufwand notwendig, was den Einsatz formaler Verifikationsmethoden in der Praxis hemmt. Zudem empfiehlt sich eine Überprüfung der zur formalen Verifikation eingesetzten Modelle. Zur Bewältigung der Herausforderungen für die Absicherung, die eine Rekonfiguration während des Betriebs nach sich zieht, werden in diesem Beitrag zwei vielversprechende und sich gegenseitig ergänzende Ansätze für die lebenszyklusübergreifende Absicherung von Produktionssystemen vorgestellt.

Electro-organic conversions at an active molybdenum anode enable the formation of fused arenes. High chemoselectivity was achieved under anodic conditions, and a reagent-induced selectivity was observed by comparison with results of MoCl5-mediated reactions. Polycyclic arenes like phenanthrenes, triphenylenes, chrysenes, or helicenes were selectively obtained in yields up to 87% and in some cases unusual rearrangements were crucial for the product formation.

Cyber-Physical Systems, characterized by networking capabilities and digital representations, offer many promising potentials for industrial automation. In an attempt to further enrich the system's digital representation by incorporating interdisciplinary models and considering a continuous and synchronized representation of it within the cyber layer, the concept of the Digital Twin emerged, enabling system monitoring, virtual commissioning, failure diagnosis and simulations by managing the Cyber-Physical Systems data along its lifecycle. To add further intelligence into the Digital Twin, the architecture of the intelligent Digital Twin was proposed. Nevertheless, managing and relating the complex and dynamic digital models as well as the heterogeneous data of the intelligent Digital Twin present open challenges. Due to their inherent extensibility and adaptability as well as their semantic expressiveness, Knowledge Graphs are a suitable concept to overcome these challenges and enable reasoning to gain new insights. Prominent applications of Knowledge Graphs are recommendation systems and exploratory search within the semantic web. However, there seems to be a lacking yet potential applicability for Knowledge Graphs in the industrial domain. Therefore, this contribution proposes a Knowledge Graph enhanced architecture of the intelligent Digital Twin, offering capabilities, which are internal linking and referencing, knowledge completion, error detection, collective reasoning and semantic querying. Based on the proposed concept, potential application fields for Knowledge Graph enhanced intelligent Digital Twin are addressed.

Journal of physics / Condensed matter 33, 105901 (2021). doi:10.1088/1361-648X/abcdb0, Diffraction and imaging using x-rays and neutrons are widely utilized in different fields ofengineering, biology, chemistry and/or materials science. The additional information gainedfrom the diffraction signal by x-ray diffraction and computed tomography (XRD-CT) can givethis method a distinct advantage in materials science applications compared to classicaltomography. Its active development over the last decade revealed structural details in anon-destructive way with unprecedented sensitivity. In the current contribution an attempt toadopt the well-established XRD-CT technique for neutron diffraction computed tomography(ND-CT) is reported. A specially designed ‘phantom’, an object displaying adaptable contrastsufficient for both XRD-CT and ND-CT, was used for method validation. The feasibility ofND-CT is demonstrated, and it is also shown that the ND-CT technique is capable to provide anon-destructive view into the interior of the ‘phantom’ delivering structural informationconsistent with a reference XRD-CT experiment., Published by IOP Publ., Bristol

Ensuring high availability despite the growing frequency of changes in production requirements leads to an increased reconfiguration demand in the domain of industrial automation systems, which will be dominated by Cyber-Physical Production Systems (CPPS) in the future. Therefore, a concept, covering a methodology containing four steps, is utilized to answer the research question how to enhance CPPS with a self-organized reconfiguration management. This contribution focuses on the first two steps of this concept: the identification of reconfiguration demand and the generation of alternative configurations. A condensed presentation of the related work reveals that an interface-oriented formalized process description depicts an appropriate conceptual basis. Building upon this, the presented concept contains a capability model of the CPPS and the reasoning to determine a potential reconfiguration demand, as well as a procedure for the generation of alternative configurations. To evaluate the concept, an agent-based implementation is given, which uses an OPC-UA controlled simulated modular production system as a substitute CPPS in discrete manufacturing.

Corrosion science 184, 109390 (2021). doi:10.1016/j.corsci.2021.109390, Synchrotron high-energy XRD measurements and ab-initio DFT calculations were employed to investigate microstructural degradation of copper upon exposure to sulfide-containing anoxic groundwater simulating nu-clear waste repository. After two-month exposure, the high-energy XRD measurements revealed heterogeneous lattice deformation in the microstructure and lattice expansion in near-surface regions. The DFT calculations show that sulfur promotes hydrogen adsorption on copper. Water causes surface reconstruction and promotes hydrogen insertion into the microstructure, occurring via interstitial sites next to vacancies leading to lattice dilation and metal bond weakening. Hydrogen infusion in the presence of sulfur caused lattice degradation, indicating a risk for H-induced cracking., Published by Elsevier Science, Amsterdam [u.a.]

Exerpt from The African American Sonnet: A Literary History by Timo Müller. Copyright © 2018 by University Press of Mississippi.

A new ultrahigh-strength structure is created by severe plastic deformation of a martensitic 0.1 wt.-% C steel using high pressure torsion (HPT) at room temperature. Tensile tests reveal an ultimate tensile strength of 2.4 ± 0.1 GPa after an equivalent strain of evM = 7.5 – to our knowledge the highest tensile strength ever reported for a carbon steel with such low carbon content. During HPT, a lamellar microstructure is formed with decreasing lamellar spacing for increasing plastic strain. Micropillar compression tests give crucial insights into the mechanical properties, which are correlated to the deformation behavior of this material. Strong similarities compared to HPT-treated pearlitic steel are found in spite of the large differences concerning both carbon content and phase composition. The possibilities and limits of strength maximization in carbon steels are evaluated and discussed.

A convenient and straightforward approach to performing oxidative coupling reactions in flow is presented. A collection of electron-rich benzene derivatives was subjected to this protocol, and the distinct utility of molybdenum pentachloride (MoCl5) is established. Using this unexplored protocol, biphenyls could be obtained in 21–91% isolated yield. This simple protocol opens a new chapter in reagent-mediated dehydrogenative coupling reactions, and yields are compared to classical approaches.

In the age of the Industrial Internet of Things, distributed subsystems are established in many domains, which bring added value through their networking. In the field of industrial automation this means a distribution of the control system. As the distribution involves an increase in complexity, new approaches are needed that address this problem. This paper presents a model-driven development approach that involves a Service Oriented Architecture.

Applied Sciences 10(15), 5094: 1-15 (2020). doi:10.3390/app10155094, Bulk nanocrystalline materials of small and medium ferromagnetic content were produced using severe plastic deformation by high-pressure torsion at room temperature. Giant magnetoresistive behavior was found for as-deformed materials, which was further improved by adjusting the microstructure with thermal treatments. The adequate range of annealing temperatures was assessed with in-situ synchrotron diffraction measurements. Thermally treated Cu–Co materials show larger giant magnetoresistance after annealing for 1 h at 300 °C, while for Cu-Fe this annealing temperature is too high and decreases the magnetoresistive properties. The improvement of magnetoresistivity by thermal treatments is discussed with respect to the microstructural evolution as observed by electron microscopy and ex-situ synchrotron diffraction measurements., Published by MDPI, Basel

Die Häufigkeit von Änderungen der Produktionsanforderungen nimmt aufgrund wirtschaftlicher Volatilität, kürzerer Innovationszyklen und Produktlebenszyklen kontinuierlich zu. Daher ist eine Vorhersage aller möglichen Ziele eines Produktionssystems zur Entwurfszeit unmöglich und es ergibt sich erhöhter Rekonfigurationsbedarf zur Betriebszeit. Derzeit weist die Rekonfiguration von Produktionssystemen jedoch einige Schwachstellen auf, die in diesem Beitrag aufgezeigt werden. Außerdem wird die Zukunft der industriellen Automatisierung von Cyber-Physischen Produktionssystemen dominiert werden, welche vielversprechende Potentiale bieten. Folglich werden die Cyber-Physischen Produktionssysteme und einige ihrer Potentiale im Hinblick auf Rekonfiguration diskutiert. Um diese theoretischen Potentiale tatsächlich nutzen zu können, sind allerdings entsprechende Konzepte erforderlich, weshalb dieser Forschungsbeitrag ein grundlegendes Konzept für ein selbstorganisiertes Rekonfigurationsmanagement präsentiert.

Corrosion science 175, 108899 (1-8) (2020). doi:10.1016/j.corsci.2020.108899, Local strain development in the microstructure of a commercial 25Cr-7Ni super duplex stainless steel was mapped using high-energy x-ray diffraction during cathodic hydrogen charging under constant uniaxial load. The infusion of hydrogen resulted in tensile strains in austenite grains, one order of magnitude larger than those in the ferrite. Most strain evolution occurred at the near-surface, with compensating compressive forces developed in underlying regions, with up to two-times more compression occurring in the ferrite than the austenite. The strains along the loading axis were more pronounced than in the transverse direction, in which mostly compressive strains developed in the ferrite., Published by Elsevier Science, Amsterdam [u.a.]

Objective: Patients' expectations about the benefit of an intervention are important determinants of the placebo effect. Little is known about the extent to which expectations influence outcomes of treatments in the field of appetite regulation. This study aimed to investigate the effects of treatment-related expectations on subjective and objective markers of appetite.Methods: 90 healthy participants of normal weight were randomly allocated to either an appetite-enhancing placebo group, a satiety-enhancing placebo group, or a control group. All participants received a placebo capsule along with group-specific verbal suggestions to either be appetite-promoting, or satiety-enhancing, or to have no effect on appetite. Before and during the 2 h following randomization, participants were repeatedly asked to rate feelings of hunger and satiety on visual analog scales (VAS), and blood samples were taken repeatedly to assess plasma ghrelin levels as a physiological marker of hunger.Results: In comparison to the control group, the satiety-enhancing placebo intervention significantly reduced appetite and increased satiety. The appetite-enhancing placebo intervention did not alter subjective levels of hunger, but increased plasma ghrelin levels in females.Conclusions: Results provide the first experimental evidence that appetite-regulating placebo interventions can elicit a psychobiological response. Expectations are important factors to consider when evaluating the effects of interventions in the field of appetite regulation.

Johann Wolfgang Goethe’s Torquato Tasso (1790) and Henry James’s Roderick Hudson (1875) share not only a number of structural parallels but also an interest in the fate of the romantic artist in a regulated society. The article suggests Goethe’s play as a possible influence on James’s novel. After a brief outline of James’s relationship to Goethe and of the structural parallels between the texts, the article discusses the similarities of their stance on the romantic artist. Both texts contrast the protagonist’s classicist-idealist art with his broadly romantic personality, both remain ambivalent about the romantic conception of the poet-genius, and both take an analytical attitude toward their artist figures. On this poetological level, the article concludes, their portraits of a proto-Romantic and a late Romantic respectively form a revealing historical frame of the phenomenon of the Romantic artist.

Some of the most famous African American poems are sonnets: Claude McKay’s “If We Must Die,” Countee Cullen’s “Yet Do I Marvel,” Gwendolyn Brooks’s “First fight. Then fiddle.” Few readers realize that these poems come from a rich tradition of more than a thousand sonnets written by African American poets over a century and a half. The African American Sonnet: A Literary History traces this forgotten tradition from the nineteenth century to the present. Based on extensive archival research, the study demonstrates that closer attention to the sonnet modifies our understanding of key developments in African American literary history. Each chapter addresses such a development: the struggle over the legacy of the Civil War, the trajectories of Harlem Renaissance protest, the tensions between folk art and transnational perspectives in the thirties, the vernacular modernism of the post-war period, the cultural nationalism of the Black Arts movement, and the disruptive strategies of recent experimental poetry. Throughout this rich history, the study argues, sonnets have been “troubling spaces” in more ways than one. The sonnet became a contested space when black poets appropriated the “scanty plot of ground” (Wordsworth) from which they had long been excluded. The sonnets written by these poets troubled the material and discursive boundaries African Americans have been facing in a society organized around racial inequality. The confrontation and subversion of boundaries is inscribed into the very structure of the sonnet, which made it a preferred testing ground for such strategies in the literary realm.

When Albery Allson Whitman, a minister and former slave, published his first collection of poetry in 1877, he inaugurated an unlikely genre: the African American sonnet.1 This was an altogether remarkable event. An ethnic group that had largely been excluded from intellectual life was beginning to appropriate one of the most venerable traditions in Western literature. A group whose capabilities had widely been disparaged was demonstrating its mastery of one of the most complex poetic forms in the language. A group whose cultural heritage had mainly relied on oral transmission was turning to one of the most durable genres in written literature. It was a development few were prepared to acknowledge or accept—as June Jordan, herself a writer of sonnets, would put it many years later, it was “not natural” (...