41 research outputs found

    Universal response of the type-II Weyl semimetals phase diagram

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    The discovery of Weyl semimetals represents a significant advance in topological band theory. They paradigmatically enlarged the classification of topological materials to gapless systems while simultaneously providing experimental evidence for the long-sought Weyl fermions. Beyond fundamental relevance, their high mobility, strong magnetoresistance, and the possible existence of even more exotic effects, such as the chiral anomaly, make Weyl semimetals a promising platform to develop radically new technology. Fully exploiting their potential requires going beyond the mere identification of materials and calls for a detailed characterization of their functional response, which is severely complicated by the coexistence of surface- and bulk-derived topologically protected quasiparticles, i.e., Fermi arcs and Weyl points, respectively. Here, we focus on the type-II Weyl semimetal class where we find a stoichiometry-dependent phase transition from a trivial to a non-trivial regime. By exploring the two extreme cases of the phase diagram, we demonstrate the existence of a universal response of both surface and bulk states to perturbations. We show that quasi-particle interference patterns originate from scattering events among surface arcs. Analysis reveals that topologically non-trivial contributions are strongly suppressed by spin texture. We also show that scattering at localized impurities generate defect-induced quasiparticles sitting close to the Weyl point energy. These give rise to strong peaks in the local density of states, which lift the Weyl node significantly altering the pristine low-energy Weyl spectrum. Visualizing the microscopic response to scattering has important consequences for understanding the unusual transport properties of this class of materials. Overall, our observations provide a unifying picture of the Weyl phase diagram

    Digitalized manufacturing logistics in engineer-to-order operations

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    This is a post-peer-review, pre-copyedit version of an article published in Advances in Production Management Systems. Production Management for the Factory of the Future. APMS 2019. IFIP Advances in Information and Communication Technology, vol. 566. The final authenticated version is available online at: https://doi.org/10.1007/978-3-030-30000-5_71. The high complexity in Engineer-To-Order (ETO) operations causes major challenges for manufacturing logistics, especially in complex ETO, i.e. one-of-a-kind production. Increased digitalization of manufacturing logistics processes and activities can facilitate more efficient coordination of the material and information flows for manufacturing operations in general. However, it is not clear how to do this in the ETO environment, where products are highly customized and production is non-repetitive. This paper aims to investigate the challenges related to manufacturing logistics in ETO and how digital technologies can be applied to address them. Through a case study of a Norwegian shipyard, four main challenges related to manufacturing logistics are identified. Further, by reviewing recent literature on ETO and digitalization, the paper identifies specific applications of digital technologies in ETO manufacturing. Finally, by linking manufacturing logistics challenges to digitalization, the paper suggests four main features of digitalized manufacturing logistics in ETO: (i) seamless, digitalized information flow, (ii) identification and interconnectivity, (iii) digitalized operator support, and (iv) automated and autonomous material flow. Thus, the paper provides valuable insights into how ETO companies can move towards digitalized manufacturing logistics

    der Ludwig-Maximilians-Universität München The Eukaryotic Chaperonin TRiC Domain-Wise Folding of Multi-Domain Proteins

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    I would like to thank Prof. Dr. F.-Ulrich Hartl for giving me the opportunity to work in his laboratory and for his optimism and his creative input during the entire course of my project. I would like to thank my supervisors Dr. Stephanie Etchells and Dr. Andreas Bracher. Many obstacles have been overcome by their support. Their questions and ideas shaped the project significantly. I would like to thank Dr. Markus Stemp who had started the project and who introduced me into many of the necessary skills and techniques. I would like to thank my colleagues in the lab for creating a unique working atmosphere and for many shared moments that I will never forget. I would like to thank Dr. Birgitta Beatrix and Prof. Dr. Don Lamb for the discussions during the TAC meetings that provided helpful external input. I would like to thank the members of my PhD committee PD Dr. Dr. Konstanze Winklhofer, P

    Folding of large multidomain proteins by partial encapsulation in the chaperonin TRiC/CCT

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    The eukaryotic chaperonin, TRiC/CCT (TRiC, TCP-1 ring complex; CCT, chaperonin containing TCP-1), uses a built-in lid to mediate protein folding in an enclosed central cavity. Recent structural data suggest an effective size limit for the TRiC folding chamber of similar to 70 kDa, but numerous chaperonin substrates are substantially larger. Using artificial fusion constructs with actin, an obligate chaperonin substrate, we show that TRiC can mediate folding of large proteins by segmental or domain-wise encapsulation. Single or multiple protein domains up to similar to 70 kDa are stably enclosed by stabilizing the ATP-hydrolysis transition state of TRiC. Additional domains, connected by flexible linkers that pass through the central opening of the folding chamber, are excluded and remain accessible to externally added protease. Experiments with the physiological TRiC substrate hSnu114, a 109-kDa multidomain protein, suggest that TRiC has the ability to recognize domain boundaries in partially folded intermediates. In the case of hSnu114, this allows the selective encapsulation of the C-terminal similar to 45-kDa domain and segments thereof, presumably reflecting a stepwise folding mechanism. The capacity of the eukaryotic chaperonin to overcome the size limitation of the folding chamber may have facilitated the explosive expansion of the multidomain proteome in eukaryotes

    Implementing the Cognition Level for Industry 4.0 by Integrating Augmented Reality and Manufacturing Execution Systems

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    In the current industrial practices, the exponential growth in terms of availability and affordability of sensors, data acquisition systems, and computer networks forces factories to move toward implementing high integrating Cyber-Physical Systems (CPS) with production, logistics, and services. This transforms today’s factories into Industry 4.0 factories with significant economic potential. Industry 4.0, also known as the fourth Industrial Revolution, levers on the integration of cyber technologies, the Internet of Things, and Services. This paper proposes an Augmented Reality (AR)-based system that creates a Cognition Level that integrates existent Manufacturing Execution Systems (MES) to CPS. The idea is to highlight the opportunities offered by AR technologies to CPS by describing an application scenario. The system, analyzed in a real factory, shows its capacity to integrate physical and digital worlds strongly. Furthermore, the conducted survey (based on the Situation Awareness Global Assessment Technique method) reveals significant advantages in terms of production monitoring, progress, and workers’ Situation Awareness in general

    Identifying the Opportunities for Enhancing the Digital Readiness Level of the Supply Chain

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    Part 8: Digital and Smart Supply Chain ManagementInternational audienceAssessing the digital readiness of companies is becoming crucial to undertake a successful journey towards the digitalization of industry. Recently, the attention of both scholars and practitioners has turned to an extension of the assessment to the whole Supply Chain (SC). Given the importance of reaching a high level of integration and digital readiness in all the various actors that collaborate in the SC, some Digital Supply Chain (DSC) assessment models have been proposed mainly in the consulting field. However, to fully exploit the benefits of measuring the digital readiness of a SC, companies need also to be supported in the identification and prioritization of the most relevant opportunities triggered by the deployment of DSC projects. To this purpose, this paper presents a framework that links the potentials of DSC implementations with the SC operation processes, highlighting the most suitable technologies to deploy them. The framework has been conceived starting from a literature review and aims at providing a valuable tool to all the stakeholders involved in the transformation towards Digital Supply Chains
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