Publikationen

2021

• Grid Services and Stress Reduction with a Flywheel in the Rotor of a Wind Turbine

  Jauch, C. (2021). Grid Services and Stress Reduction with a Flywheel in the Rotor of a Wind Turbine. Energies, 14. http://doi.org/10.3390/en14092556

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  Wind power penetration increases in most grids and the sizes of wind turbines increase. This leads to increasingly tough requirements, which are imposed on wind turbines, both from the grid as well as from economics. Some of these partially contradictory requirements can only be satisfied with additional control mechanisms in the wind turbines. In this paper, such a mechanism, i.e., a hydraulic–pneumatic flywheel system in the rotor of a wind turbine, is discussed. This flywheel system supports a wind turbine in providing grid services such as steadying the power infeed, fast frequency response, continuous inertia provision, power system stabilization, and low voltage ride-through. In addition, it can help mitigate the stress on the mechanical structure of a wind turbine, which results from varying operating points, imbalances in the rotor, gravitation that acts on the blades, in-plane vibrations, and emergency braking. The study presented in this paper is based on simulations of a publicly available reference wind turbine. Both the rotor blade design as well as the design of the flywheel system are as previously published. It is discussed how the aforementioned grid services and the stress reduction mechanisms can be combined. Finally, it is concluded that such a flywheel system broadens the range of control mechanisms of a wind turbine substantially, which is beneficial for the grid as well as for the wind turbine itself.

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    • Jauch, Clemens

  • Fachbereich

    • Fachbereich 2: Energy and Life Science

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  • 2021
  • Journal Article
  • • Prof. Dr. Clemens Jauch

• Financial performance and firm efficiency of automotive manufacturers and their suppliers A longitudinal data envelopment analysis

  Brandenburg, M., & Hahn, G. J. (2021). Financial performance and firm efficiency of automotive manufacturers and their suppliers A longitudinal data envelopment analysis. Logistics Research, 14(1), 26. http://doi.org/10.23773/2021_01

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  A data envelopment analysis (DEA) is presented to assess evolutions of firm efficiency and financial performance in automotive supply chains. A sample of 32 decision-making units (DMUs), 17 globally operating original equipment manufacturers (OEMs) and 15 key suppliers from the automotive industry, is in focus of this analysis in which cost levels and capital requirements are put into relation to sales growth and profit. Cost of goods sold, operating capital, and net fixed assets represent the financial input of a company while sales growth and earnings before interest and taxes (EBIT) reflect the financial output. The financial performance of a firm is indicated by its efficiency, calculated by an input-oriented variable returns to scale model. A multiple linear regression analysis reveals which operational performance factors are predictors of financial performance. A longitudinal DEA approach that covers the years from 2003 to 2017 is chosen to reveal performance evolutions over time. In order to analyze the stability of relationships between efficient firms (peers) and inefficient ones (followers) over time, changes in the performance relationship network are assessed in a graph-theoretic approach. In this study, geographical and structural specifics of DMU groups are taken into account. The study reveals similarities and differences between OEMs and their suppliers regarding the importance of value drivers and detects periods of performance losses and recovery from the global economic crisis.

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    • Brandenburg, Marcus

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  • 2021
  • Journal Article
  • • Marcus Brandenburg
    • Gerd Hahn
  • • Automotive industry
    • Data Envelopment Analysis
    • Financial performance
    • Supply networks

• Arbeiten Frauen aufgrund des Ehegattensplittings weniger? — Eine empirische Untersuchung für Deutschland

  Chirvi, M. (2021). Arbeiten Frauen aufgrund des Ehegattensplittings weniger? — Eine empirische Untersuchung für Deutschland. Steuer und Wirtschaft, 98(2). http://doi.org/10.9785/stuw-2021-980207

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  Der Beitrag soll zur Klärung der Frage beitragen, ob das Ehegattensplitting, wie vielfach behauptet wird, einen negativen Einfluss auf das Arbeitsverhalten verheirateter Frauen hat. Hierzu kommt für Deutschland erstmals ein von Quasi-Experimenten inspirierter Ansatz zum Einsatz, bei dem anhand des allgemeinen Effekts der Heirat auf das Erwerbsverhalten der heiratenden Frauen die Wirkung des Ehegattensplittings geschätzt wird. Die Veränderung des Arbeitsverhaltens heiratender Frauen wird dabei der Veränderung bei jenen Frauen gegenübergestellt, die im gleichen Zeitraum weiterhin mit ihrem festen Partner zusammenleben, ohne zu heiraten (Kontrollgruppe). Die Ergebnisse sprechen eindeutig gegen einen unmittelbaren negativen Effekt des Ehegattensplittings auf das Erwerbsverhalten von Frauen. Jedoch reduzieren heiratende und zeitgleich ein Kind bekommende Frauen ihre Erwerbstätigkeit stärker als gebärende Frauen in der Kontrollgruppe. In Folge einer lediglich teilweisen Abschaffung des Ehegattensplittings, die in den Entwürfen zu Parteiprogrammen zur Bundestagswahl 2021 teilweise gefordert wird, sind sogar noch geringere Effekte auf das Arbeitsverhalten zu erwarten.

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    • Chirvi, Malte

  • Fachbereich

    • Fachbereich 4: Wirtschaft

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  • 2021
  • Journal Article
  • • Malte Chirvi

• Tower and Foundation

  Faber, P. D.-I. T. (2021). Tower and Foundation. In Understanding Wind Power Technology, Theory, Deployment and Optimisation. John Wiley & Sons.

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    • Faber, Torsten

  • Abteilung/Einrichtung

    • Wind Energy Technology Institute

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  • 2021
  • Book Chapter
  • • Prof. Dr.-Ing. Torsten Faber
  • • WETI

• Ciona intestinalis in the spotlight of metabolomics and microbiomics : New insights into its invasiveness and the biotechnological potential of its associated microbiota

  Utermann, C., Tasdemir, D., & Labes, A. (2021). Ciona intestinalis in the spotlight of metabolomics and microbiomics : New insights into its invasiveness and the biotechnological potential of its associated microbiota (S. Online-Ressource). Kiel: Universitätsbibliothek Kiel.

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  • 2021
  • Book
  • • Caroline Utermann
    • Deniz Tasdemir
    • Antje Labes

• Abschlussbericht New 4.0, Norddeutsche Energiewende, SINTEG Teilprojekt AP 7: Aus- und Weiterbildung

  Faber, P. D.-I. T., & Rogalla, I. (2021). Abschlussbericht New 4.0, Norddeutsche Energiewende, SINTEG Teilprojekt AP 7: Aus- und Weiterbildung.

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    • Faber, Torsten

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    • Wind Energy Technology Institute

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  • 2021
  • Report
  • • Prof. Dr.-Ing. Torsten Faber
    • I. Rogalla
  • • WETI

• \# Covid-19: An Exploratory Investigation of Hashtag Usage on Twitter

  Petersen, K., & Gerken, J. M. (2021). \# Covid-19: An Exploratory Investigation of Hashtag Usage on Twitter. Health Policy.

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    • Petersen, Kai
    • Gerken, Jan Michael

  • Abteilung/Einrichtung

    • FLAIR - Flensburg Artificial Intelligence Research

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  • 2021
  • Journal Article
  • • Kai Petersen
    • Jan Gerken

• Marine microbial-derived molecules and their potential medical and cosmetic applications )

  Zhang, J., Zeng, R., & Labes, A. (2021). Marine microbial-derived molecules and their potential medical and cosmetic applications ). Frontiers in Microbiology, 12, 1965. http://doi.org/10.3389/FMICB.2021.706152

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  • 2021
  • Journal Article
  • • J. Zhang
    • R. Zeng
    • Antje Labes

• Namibian State of Logistics 2020 Report

  Oelze, N., Simasiku, B. M., & Jackie, L. L. (2021). Namibian State of Logistics 2020 Report. Windhoek: Namibian-German Centre for Logistics. Abgerufen von https://www.giz.de/en/downloads/NGCL_Namibia-State-of-Logistics_Report2020-1.pdf

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  This document has been prepared to summarise the findings of a study carried out by the Namibian-German Centre for Logistics into the current state of logistics in Namibia during the period from 2018 to 2020 and the impact of the Covid-19 pandemic on the industry. It updates studies carried into Namibian logistics in 2012 and 2018. The study has been undertaken by the research team on an wholly independent basis making use of contemporary data available in the public domain and surveys conducted by the team. It reflects the opinions of the authors based of review and analysis of the available evidence.

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    • Fachbereich 4: Wirtschaft

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  • 2021
  • Report
  • • Nelly Oelze
    • Brighten Simasiku
    • Lydia Jackie

• Preliminary Evaluation of a Survey Checklist in the Context of Evidence-based Software Engineering Education.

  Petersen, K., & eri, J. S. M. (2021). Preliminary Evaluation of a Survey Checklist in the Context of Evidence-based Software Engineering Education. In ENASE (S. 437–444).

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    • Petersen, Kai

  • Abteilung/Einrichtung

    • FLAIR - Flensburg Artificial Intelligence Research

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  • 2021
  • Conference Paper
  • • Kai Petersen
    • Jefferson eri