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Das forschungsgetriebene Lehrformat "Projektorientiertes Lernen" wird im Masterprogramm der Fakultät Angewandte Chemie der Hochschule Reutlingen von uns seit nunmehr einer Dekade eingesetzt und stetig weiter entwickelt. Dieses Format hat sich besonders bewährt, um methodische und fachliche Kompetenzen nachhaltig zu vermitteln. Es war uns ein Anliegen, auch anderen an der praxisorientierten Ausgestaltung der Lehre Interessierten unsere Erfahrungen mitzuteilen und unsere Vorgehensweise konkret vorzustellen. Dazu haben wir unsere bisher verwendeten Dokumente und Veröffentlichungen zu diesem Thema redigiert und stellen sie in dem vorliegenden Buch vor. In diesem von uns als "Kurshandbuch" für Anwender gedachten Werk finden sich unsere über Jahre gesammelten Erfahrungen mit der Organisation eines solchen Lehr- und Lernformats.
The increasing heterogenecity of students at German Universities of Applied Sciences and the growing importance of digitization call for a rethinking of teaching and learning within higher education. In the next years, changing the learning ecosystem by developing and reflecting upon new teaching and learning techniques using methods of digitalization will be both - most relevant and very challenging. The following article introduces two different learning scenarios, which exemplify the implementation of new educational models that allow discontinuity of time and place, technology and process in teaching and learning. Within a blended learning apporach, the first learning scenario aims at adapting and individualizing the knowledge transfer in the course Foundations of Computer Science by providing knowledge individually and situation-specifically. The second learning scenario proposes a web-based tool to facilitate digital learning environments and thus digital learning communities and the possibility of computer-supported learning. The overall aim of both learning scenarios is to enhance learning for diverse groups by providing a different smart learning ecosystem in stepping away from a teacher-based to a student-centered approach. Both learning scenarios exemplarily represent the educational vision of Reutlingen University - its development into an interactive university.
Sowohl die Zahl als auch die Relevanz gemeinnütziger Vereine in und für Deutschland ist immens. Gleichwohl erstaunt, dass die Rechnungslegung gemeinnütziger Vereine nur rudimentär geregelt ist und in der Forschungspraxis bisher eher wenig beleuchtet wird. Vor allem für die oftmals nur ehrenamtlich tätigen Vereinsvorstände stellt dies eine Herausforderung dar. Der vorliegende Beitrag schafft einen Überblick über die aktuelle Situtation der Vereinsrechnungslegung in Deutschland und erhebt im Rahmen einer empirischen Untersuchung die aktuellen Herausforderungen. Aus den Ergebnissen lassen sich wichtige Implikationen für die rechnungslegenden Vereine, die Adressaten dieser Rechnungslegung, den Gesetzgeber und die Prüfer der Berichte ableiten.
Nachhaltige Managementmodelle sind auf Erfüllung der Triple Bottom Line ausgerichtet: Unternehmen adressieren Energie- und Co2-Effizienz (ökologisch), Arbeitsschutz oder Arbeitslosenquoten (sozial) sowie mögliche Wachstumspotenziale, die durch Nachhaltigkeit zu erreichen sind, um das eigene Überleben des Unternehmens am Markt zu sichern (ökonomisch). Daneben stehen die 17 Sustainable Development Goals (SDGs), die bis 2030 als Leitlinie nachhaltigen Wirtschaftens weltweit gelten und in nationale Gesetzgebung überführt wurden. Dieser Beitrag entwickelt ein Managementmodell, das Unternehmen dabei unterstützt, relevante SDGs zu identifizieren und Handlungsempfehlungen abzuleiten. Aufbauend auf einer nachhaltigen Supply Chain ordnet das Modell die SDGs den Dimensionen der Triple Bottom Line zu, um kurz eine Checkliste möglicher zu berücksichtigender Nachhaltigkeitsmaßnahmen im Kontext des Behaviour Change Modells zu erarbeiten. Zurückgreifend auf die Empfehlungen der Vereinten Nationen wird ein nachhaltiger Managementansatz eingeführt, der Unternehmen dazu befähigt, Governance, Transparenz und Engagement in ihrer Supply Chain zu implementieren.
Defining the antecedents of experience co-creation as applied to alternative consumption models
(2019)
Purpose – The purpose of this paper is to propose a conceptual framework of experience co-creation that captures the multi-dimensionality of this construct, as well as a research process for defining of the antecedents of experience co-creation.
Design/methodology/approach – The framework of experience co-creation was conceptualized by means of a literature review. Subsequently, this framework was used as the conceptual basis for a qualitative content analysis of 66 empirical papers investigating alternative consumption models (ACMs), such as renting, remanufacturing, and second-hand models.
Findings – The qualitative content analysis resulted in 12 categories related to the consumer and 9 related to the ACM offerings that represent the antecedents of experience co-creation. These categories provide evidence that, to a large extent, the developed conceptual framework allows one to capture the multi-dimensionality of the experience co-creation construct.
Research limitations/implications – This study underscores the understanding of experience co-creation as a function of the characteristics of the offering – which are, in turn, a function of the consumers’ motives as determined by their lifeworlds – as well as to service design as an iterative approach to finding, creating and refining service offerings.
Practical implications – The investigation of the antecedents of experience co-creation can enable service providers to determine significant consumer market conditions for forecasting the suitability and viability of their offerings and to adjust their service designs accordingly.
Originality/value – This paper provides a step toward the operationalization of the dimension-related experience co creation construct and presents an approach to defining the antecedents of experience co-creation by considering different research perspectives that can enhance service design research.
Manufacturing has to adapt to changing situations in order to stay competitive.It demands a flexible and easy-to-use integration of production equipment and ICT systems. The contribution of this paper is the presentation of the implementation of the Manufacturing Integration Assistant (MIALinx). The integration steps range from integrating sensors over collecting and rule-based processing of sensor information to the execution of required actions. Furthermore, we describe the implementation of MIALinx by commissioning it in a manufacturing environment to retrofit legacy machines for Industrie 4.0. Finally, we validate the suitability of our approach by applying our solution in a medium-size company.
We present a compact battery charger topology for weight and cost sensitive applications with an average output current of 9A targeted for 36V batteries commonly found in electric bicycles. Instead of using a conventional boost converter with large DC-link capacitors, we accomplish PFC-functionality by shaping the charging current into a sin²-shape. In addition, a novel control scheme without input-current sensing is introduced. A-priori knowledge is used to implement a feed-forward control in combination with a closed-loop output current control to maintain the target current. The use of a full-bridge/half bridge LLC converter enables operation in a wide input-voltage range.
A fully featured prototype has been built with a peak output power of 1050W. An average output power of 400W was measured, resulting in a power density of 1.8 kW/dm³. At 9A charging current, a power factor of 0.96 was measured and the efficiency exceeds 93% on average with passive rectification.
The impact of pulse charging has been evaluated on a 400Wh battery which was charged with the proposed converter as well as CC-CV-charging for reference. Both charging schemes show similar battery surface temperatures.
Age-dependent migratory behavior of human endothelial cells revealed by substrate microtopography
(2019)
Cell migration is part of many important in vivo biological processes and is influenced by chemical and physical factors such as substrate topography. Although the migratory behavior of different cell types on structured substrates has already been investigated, up to date it is largely unknown if specimen's age affects cell migration on structures. In this work, we investigated age-dependent migratory behavior of human endothelial cells from young (≤ 31 years old) and old (≥ 60 years old) donors on poly(dimethylsiloxane) microstructured substrates consisting of well-defined parallel grooves. We observed a decrease in cell migration velocity in all substrate conditions and in persistence length perpendicular to the grooves in cells from old donors. Nevertheless, in comparison to young cells, old cells exhibited a higher cell directionality along grooves of certain depths and a higher persistence time. We also found a systematic decrease of donor age dependent responses of cell protrusions in orientation, velocity and length, all of them decreased in old cells. These observations lead us to hypothesize a possible impairment of actin cytoskeleton network and affected actin polymerization and steering systems, caused by aging.
Information technology (IT) plays an essential role in organizational innovation adoption. As such, IT governance (ITG) is paramount in accompanying IT to allow innovation. However, the traditional concept of ITG to control the formulation and implementation of IT strategy is not fully equipped to deal with the current changes occurring in the digital age. Today’s ITG needs an agile approach that can respond to changing dynamics. Consequently, companies are relying heavily on agile strategies to secure better company performance. This paper aims to clarify how organizations can implement agile ITG. To do so, this study conducted 56 qualitative interviews with professionals from the banking industry to identify agile dimensions within the governance construct. The qualitative evaluation uncovered 46 agile governance dimensions. Moreover, these dimensions were rated by 29 experts to identify the most effective ones. This led to the identification of six structure elements, eight processes, and eight relational mechanisms.
Many start-ups are in search of cooperation partners to develop their innovative business models. In response, incumbent firms are introducing increasingly more cooperation systems to engage with start-ups. However, many of these cooperations end in failure. Although qualitative studies on cooperation models have tried to improve the effectiveness of incumbent start-up strategies, only a few have empirically examined start-up cooperation behavior. Considering the lack of adequate measurement models in current research, this paper focuses on developing a multi-item scale on cooperation behavior of start-ups, drawing from a series of qualitative and quantitative studies. The resultant scale contributes to recent research on start-up cooperation and provides a framework to add an empirical perspective to current research.
Die Digitalisierung im Einkauf findet als schleichender Prozess statt, wird allerdings vom Vertrieb nur ungenügend wahrgenommen und genutzt. In Anbetracht der bereits hohen, weiter wachsenden Quote eingekaufter Waren und Leistungen an den Umsatzkosten ein kritischer Befund. Fehlinterpretationen der Anforderungen sind die Folge. Wie kann man hier Abhilfe schaffen? Eine Analyse der Entwicklungen im Einkauf zeigt Handlungsempfehlungen für den Vertrieb auf und fordert eine schnelle Reaktion.
Virtual Reality (VR) technology has the potential to support knowledge communication in several sectors. Still, when educators make use of immersive VR technology in favor of presenting their knowledge, their audience within the same room may not be able to see them anymore due to wearing head-mounted displays (HMDs). In this paper, we propose the Avatar2Avatar system and design, which augments the visual aspect during such a knowledge presentation. Avatar2Avatar enables users to see both a realistic representation of their respective counterpart and the virtual environment at the same time. We point out several design aspects of such a system and address design challenges and possibilities that arose during implementation. We specifically explore opportunities of a system design for integrating 2D video-avatars in existing roomscale VR setups. An additional user study indicates a positive impact concerning spatial presence when using Avatar2Avatar.
Representing users within an immersive virtual environment is an essential functionality of a multi-person virtual reality system. Especially when communicative or collaborative tasks must be performed, there exist challenges about realistic embodying and integrating such avatar representations. A shared comprehension of local space and non-verbal communication (like gesture, posture or self-expressive cues) can support these tasks. In this paper, we introduce a novel approach to create realistic, video-texture based avatars of colocated users in real-time and integrate them in an immersive virtual environment. We show a straight forward and low-cost hard- and software solution to do so. We discuss technical design problems that arose during implementation and present a qualitative analysis on the usability of the concept from a user study, applying it to a training scenario in the automotive sector.
Der vorliegende Beitrag zeigte die Anwendung eines Extended Kalman Filters für die Beurteilung des Verschleißzustandes von Rollenketten. Anders als in den üblicherweise eingesetzten signalbasierten Verfahren wurde damit ein modellbasierter Ansatz gewählt. Der Einsatz des Extended Kalman Filters ermöglicht die Schätzung von Parametern eines reduzierten Kettenmodells, das die Dynamik der einzigen Messgröße, nämlich des Drehmoments des antreibenden Motors näherungsweise nachbildet. Im Beitrag wurde dieses Verfahren auf Messdaten aus vier Dauerversuchen an Rollenketten eingesetzt und gezeigt, dass mit steigendem Verschleiß eine Änderung ausgewählter Modellparameter erfolgt.
Diese Vorgehensweise ist ein erster Ansatz, der durch weitere Forschungsarbeiten noch verbessert werden muss. In zukünftigen Forschungsarbeiten wird zusätzlich zur Parameterschätzung eine Prädiktion durchgeführt, um einen Schätzwert für die Restlebensdauer zu erhalten. Hierzu gibt es Ansätze in der Literatur, die auf das konkrete Problem angepasst werden müssen. Zudem muss die Modellierungssystematik so erweitert werden, dass Wissen über das Prozessverhalten in die Modellierung mit eingebracht wird, um die Aussagekraft der Ergebnisse sowie die Robustheit des Verfahrens bezüglich Betriebsparametern, Umgebungsbedingungen und Exemplarstreuungen zu verbessern.
Um sich den neuen Herausforderungen zu stellen und eine wettbewerbsstarke Position im Zeitalter der Digitalisierung zu schaffen, wird vermehr in Digitalisierungsvorhaben investiert und digitale Geschäftsmodelle werden entwickelt. Was brauch ein mittelständisches Unternehemen, um sich erfolgreich in das digitale Zeitalter aufzumachen?
Hauptziel des Projektes war zum einen die Entwicklung einer validen Testmethode auf Grundlage vorliegender Normen, welche die in der betrieblichen Praxis auftretende Degradation abreinigbarer Filtermedien (hohe Temperaturen, aggressive chemische Atmosphären) praxisnah abbilden kann. Die Methode sollte auch die mechanische Alterung der Medien durch Staubbeaufschlagung sowie Abreinigungs Druckstöße berücksichtigen (DIN ISO 11057). Innerhalb des Projektes konnten umfangreiche Praxiserfahrungen mit der Inbetriebnahme und dem Betrieb einer schadgasbeaufschlagten, temperierbaren Testkammer zur chemischen Alterung von Filtermedien auf Grundlage der Vorgaben der DIN EN ISO 16891 gewonnen werden. Sollen vergleichbare Prüfdaten für mehrere Proben verlässlich ermittelt werden, sind bei den Untersuchungen demnach umfangreiche Randbedingungen zu beachten. Insbesondere zeigten die Untersuchungen den hohen technischen Aufwand zur Durchführung der Filtertests auf, welche nicht zuletzt auch aufgrund der erforderlichen Sicherheitstechnik und langen Untersuchungsdauer eine Umsetzung insbesondere bei KMU aus wirtschaftlichen Gründen erschwert ist. Es konnte weiter dargestellt werden, dass die Kombination von chemisch-thermischer und mechanisch(-thermischer) Alterung durch den Einsatz verschiedener Prüfeinrichtungen grundsätzlich umsetzbar ist. Die im Rahmen des Vorhabens entwickelte Testmethode einer chemischen Alterung der Filtermatrices durch Gasphasenexposition in einer Druckkammer ermöglicht kürzere Beanspruchungszeiträume bei reduziertem zu behandelnden Schadgasanfall und kann damit den wirtschaftlichen Betrieb eines entsprechenden Prüfstandes ermöglichen. Kombiniert mit der externen mechanischen Alterung durch Staubbeaufschlagung und Möglichkeit der parallelen Temperaturaufprägung gem. EN ISO 16891 auf mehrere Filtermedien-Proben lässt sich das thermisch, chemisch und mechanisch induzierte Degradationsverhalten von Filtermedien ggf. realitätsnah und mit wirtschaftlich vertretbarem Aufwand in eine Prüfvorschrift überführen. Entsprechende Validierungsarbeiten sind Bestandteil eines aktuell gestarteten Folgeprojektes. Das zweite Hauptziel des Projektes war es Ausrüstungen zu entwickeln, die zu einer verbesserten Beständigkeit gegenüber aggressiven Komponenten führen. Die Ergebnisse zeigten, dass mit dem Sol-Gelverfahren mechanisch stabile Beschichtungen auf Faservlies dauerhaft aufgetragen werden konnten, welche insbesondere die chemisch induzierte Degradation von Aramiden reduzieren können. Bei Aramiden handelt es sich um relativ teure Hochleistungsmaterialien, von welchen bekannt ist, dass ihre Beständigkeit sowohl gegen über UV-Strahlung als auch unterschiedlichen Schadgasen gering ist. Daher stellen die Beständigkeit der Materialien verbessernde Ausrüstungen eine wichtige Entwicklung für Unternehmen dar, um auf diese Weise beständigere Aramid-basierte Produkte zu erhalten. Als besonders geeignet stellten sich dabei Fluorcarbonausrüstungen, organisch-anorganische Hybride auf Basis von GPTMS und Zirkonium-haltige Ausrüstungen heraus.
In der Vergangenheit ist der Materialfluss meist mit der Produktion gewachsen. Mit steigender Produkt-Individualität erhöht sich die Anzahl der zu fertigenden Varianten in der Produktion und somit die Komplexität der Materialflüsse. Im Rahmen dieser Arbeit wurden Möglichkeiten und Methoden zur Aufnahme und Optimierung von Materialflüssen im Zusammenhang mit hoher Variantenvielfalt untersucht.
Auch das Liquiditäts- und Working Capital Management unterliegt einem ständigen Wandel. So hatte die Liquiditätssicherung nach Ausbruch der Finanzkrise 2008/09 in vielen Unternehmen höchste Priorität. In Zeiten niedriger Zinsen können die Kapitalkosten vernachlässigt werden, wodurch die Notwendigkeit sinkt, Bestände des Working Capital zu reduzieren. Bei steigenden Zinsen und/oder einer schwachen konjunkturellen Entwicklung verschärft sich dagegen der Zielkonflikt zwischen Sicherheit und Rentabilität.
Mögliche Verbesserungen ergeben sich beim Liquiditäts- und Working Capital Management durch die Digitalisierung, die den Informationsaustausch zwischen dem Unternehmen und seinemn Supply-Chain-Partnern beschleunigt. Damit lässt sich an vielen Stellen des Wertschöpfungsprozesses die Effizienz steigern.
Enterprises are presently transforming their strategy, culture, processes, and their information systems to become more digital. The digital transformation deeply disrupts existing enterprises and economies. Digitization fosters the development of IT systems with many rather small and distributed structures, like Internet of Things or mobile systems. Since years a lot of new business opportunities appeared using the potential of the Internet and related digital technologies, like Internet of Things, services computing, cloud computing, big data with analytics, mobile systems, collaboration networks, and cyber physical systems. This has a strong impact for architecting digital services and products. The change from a closed-world modeling perspective to more flexible open-world composition and evolution of system architectures defines the moving context for adaptable systems, which are essential to enable the digital transformation. In this paper, we are focusing on a decision-oriented architectural composition approach to support the transformation for digital services and products.
Revenue management information systems are very important in the hospitality sector. Revenue decisions can be better prepared based on different information from different information systems and decision strategies. There is a lack of research about the usage of such systems in small and medium-sized hotels and architectural configurations. Our paper empirically shows the current development of revenue information systems. Furthermore, we define future developments and requirements to improve such systems and the architectural base.
The aim of this work was to investigate the mean fill weight control of a continuous capsule-filling process, whether it is possible to derive controller settings from an appendant process model. To that end, a system composed out of fully automated capsule filler and an online gravimetric scale was used to control the filled weight. This setup allows to examine challenges associated with continuous manufacturing processes, such as variations in the amount of active pharmaceutical ingredient (API) in the mixture due to fluctuations of the feeders or due to altered excipient batch qualities. Two types of controllers were investigated: a feedback control and a combination of feedback and feedforward control. Although both of those are common in the industry, determining the optimal parameter settings remains an issue. In this study, we developed a method to derive the control parameters based on process models in order to obtain optimal control for each filled product. Determined via rapid automated process development (RAPD), this method is an effective and fast way of determining control parameters. The method allowed us to optimize the weight control for three pharmaceutical excipients. By conducting experiments, we verified the feasibility of the proposed method and studied the dynamics of the controlled system. Our work provides important basic data on how capsule filler can be implemented into continuous manufacturing systems.
Frost reduction in mechanical balanced ventilation by efficient means of preheating cold supply air
(2019)
This study has focused on evaluating the financial potential of wastewater and geothermal heat recovery systems in a multi-family building. The recovered heat was used to improve the performance of mechanical ventilation with heat recovery (MVHR) system during the coldest days in central Sweden. The main issue, which was targeted with these solutions, was to reduce frost formation in the system and hence increase its thermal efficiency. By looking at the life cycle cost over a lifespan of 20 years, the observed systems were being evaluated economically. Furthermore, statistical analyses were carried-out to counter the uncertainty that comes with the calculation. It was found that the studied wastewater systems have a high possibility of generating savings in this period, while the one fed by geothermal energy is less likely to compensate for its high initial cost. All designed systems however, managed to reduce operational cost by 35-45% due to lower energy usage.
We propose a method for recognizing dynamic gestures using a 3D sensor. New aspects of the developed system include problem-adapted data conversion and compression as well as automatic detection of different variants of the same gesture via clustering with a suitable metric inspired by Jaccard metric. The combination of Hidden Markov Models and clustering leads to robust detection of different executions based on a small set of training data. We achieved an increase of 5% recognition rate compared to regular Hidden Markov Models. The system has been used for human-machine interaction and might serve as an assistive system in physiotherapy and neurological or orthopedic diagnosis.
Urban platforms are essential for smart and sustainable city planning and operation. Today they are mostly designed to handle and connect large urban data sets from very different domains. Modelling and optimisation functionalities are usually not part of the cities software infrastructure. However, they are considered crucial for transformation scenario development and optimised smart city operation. The work discusses software architecture concepts for such urban platforms and presents case study results on the building sector modelling, including urban data analysis and visualisation. Results from a case study in New York are presented to demonstrate the implementation status.
Standardisation of breath sampling is important for application of breath analysis in clinical settings. By studying the effect of room airing on indoor and breath analytes and by generating time series of room air with different sampling intervals we sought to get further insights into room air metabolism, to detect the relevance of exogenous VOCs and to make conclusions about their consideration for the interpretation of exhaled breath. Room air and exhaled breath of a healthy subject were analysed before and after room airing. Furthermore a time series of room air with doors and windows closed was taken over 84 h by an automatic sampling every 180 min. A second times series studied room air analytes over 70 h with samples taken every 16.5 min. For breath and room air measurements an IMS coupled to a multi-capillary column (IMS/MCC) [Bio-Scout® - B&S Analytik GmbH, Dortmund, Germany] was used. The peaks were characterized using the Software Visual Now (B&S Analytik, Dortmund Germany) and identified using the software package MIMA (version 1.1, provided by the Max Planck Institute for Informatics, Saarbrücken, Germany) and the database 20160426_SubstanzDbNIST_122 (B & S Analytik GmbH, Dortmund, Germany). In the morning 4 analytes (Decamethylcylopentasiloxane [541-02-6]; Pentan-2-one [107-87-9] – Dimer; Hexan-1-al [66-25-1]; Pentan-2-one [107-87-9]) – Monomer showed high intensities in the room air and exhaled breath. They were significantly but not equally reduced by room airing. The time series about 84 h showed a time dependent decrease of analytes (limonen-monomer and -dimer; Decamethylcylopentasiloxane, Butan-1-ol, Butan-1-ol) as well as increase (Pentan-2-one [107-87-9] – Dimer). Shorter sampling intervals exhibited circadian variations of analyte concentrations for many analytes. Breath sampling in the morning needs room airing before starting. Then the variation of the intensity of indoor analytes can be kept small. The time series of indoor analytes show, that their intensities have a different behaviour, with time dependent declines, constant increases and circadian variations, dependent on room airing. This has implications on the breath sampling procedure and the intrepretation of exhaled breath.
Exogenous factors of influence on exhaled breath analysis by ion-mobility spectrometry (MCC/IMS)
(2019)
The interpretation of exhaled breath analysis needs to address to the influence of exogenous factors, especially to a transfer of confounding analytes by the test persons. A test person who was exposed to a disinfectant had exhaled breath analysis by MCC/IMS (Bioscout®) after different time intervals. Additionally, a new sampling method with inhalation of synthetic air before breath analysis was tested. After exposure to the disinfectant, 3-Pentanone monomer, 3-Pentanone dimer, Hexanal, 3-Pentanone trimer, 2-Propanamine, 1-Propanol, Benzene, Nonanal showed significantly higher intensities, in exhaled breath and air of the examination room, compared to the corresponding baseline measurements. Only one ingredient of the disinfectant (1-Propanol) was identical to the 8 analytes. Prolonging the time intervals between exposure and breath analysis showed a decrease of their intensities. However, the half-time of the decrease was different. The inhalation of synthetic air - more than consequently airing the examination room with fresh air - reduced the exogenous and also relevant endogenous analytes, leading to a reduction and even changing polarity of the alveolar gradient. The interpretation of exhaled breath needs further knowledge about the former residence of the proband and the likelihood and relevance of the inhalation of local, site-specific and confounding exogenous analytes by him. Their inhalation facilitates a transfer to the examination room and a detection of high concentrations in room air and exhaled breath, but also the exhalation of new analytes. This may lead to a misinterpretation of these analytes as endogenous resp. disease-specific ones.
Im Frühjahr 1817 unternahm der damalige Professor Friedrich List an der Universität Tübingen eine Reise nach Frankfurt a. M., wo zu dieser Zeit die berühmte Ostermesse stattfand. Dort traf er mit den Anführern der Kaufleute zusammen, die darüber klagten, dass die zaghafte wirtschaftliche Entwicklung unter den vielen Zollschranken und den Billigimporten aus England stark zu leiden habe. Deshalb forderten sie die Abschaffung der Binnenzölle und die Bildung einer Wirtschaftsunion. Im Auftrag der Kaufleute verfasste List seine berühmt gewordene Petition an die Bundesversammlung, die lose Interessenvertretung des Deutschen Bundes in Frankfurt. Als die Petition mit großem Beifall aufgenommen wurde, gründete List im Hochgefühl seines Erfolges spontan den "Allgemeinen Deutschen Handels- und Gewerbsverein" – die erste Interessenvertretung deutscher Kaufleute. Er legte damit den Grundstein für den politischen Prozess zur Gründung des Zollvereins von 1834, der wiederum die Vorstufe zur Gründung des Deutschen Reiches von 1871 bildete. Lists damalige Forderungen sind zurzeit wieder hoch aktuell.
Woven piezoelectric sensors as part of the textile reinforcement of fiber reinforced plastics
(2019)
Sensor integration in fiber reinforced plastic (FRP) structures enables online process and structural health monitoring (SHM). This paper describes the development and application of woven fabric-based piezoelectric impact and bending sensors for integration into FRP. The work focuses on design and characterization of woven piezoelectric sensors, especially as a part of the reinforcement structure. The reinforcement of the component acts as a sensor in itself and therefore no additional external objects in the form of sensor components or sensor fibers, which could create unwanted weak points within the FRP, are added. The bending test results reveal a direct relationship between the applied load and the sensor signal. Furthermore, the appropriate sensor position in the component cross section was determined and the influence of thermal polarization on the sensor properties was investigated.
In addition to increased safety by detecting possible overload, continuous component monitoring by sensor integration makes the use of fiber reinforced plastics more cost-effective. Since the components are continuously monitored, one can switch from time-based to condition-based maintenance. However, the integration of conventional sensor components causes weak points, as foreign objects are inserted into the reinforcing structure. In this paper, we examine the use of the textile reinforcement as a sensor in itself. We describe how bending sensors can be formed by slightly modifying in the composite’s reinforcement structure. We investigated two different sensor principles. (1) The integration of textile plate capacitors into the structure; (2) The construction of textile piezo elements as part of the reinforcing structure. The bending test results reveal that textile plate capacitors show a load-dependent signal output. The samples with textile piezo elements show a significant increase in signal strength.
In spite of many studies, knowledge about the fundamental factors influencing adhesion between addition curing silicones and aluminum substrates is very limited. The aim of this publication is to evaluate the influence of the formulation and the surface state of the adherend on bond strength. For this purpose, the composition of an addition curing silicone was systematically varied and the effects on both material and bond properties were examined. Additionally, the influence of surface aging at different humidities (0% r. h., 34% r. h., 82% r. h.) of acid etch pretreated aluminum substrates was considered. It is shown that the mechanical properties of the silicone material can be easily adjusted over a wide range by changing the formulation. Although high tensile strengths up to 9.2 MPa for the silicone material can be achieved, lap-shear strengths remain moderate at approximately 3.5 MPa. Predominant adhesive failures show the limited adhesive strength of the basic formulation without additives. Basic ingredients of addition curing silicones without additives are able to reach a certain adhesive strength. However, this strength was quite limited and adhesion promoters are required to further improve adhesion. The humidity at which the pretreated substrates are stored has an overall minor influence on bond strength. Surprisingly, bond strength tends to increase with the storage time of aluminum substrates despite lower surface energies in comparison to freshly pretreated substrates. All in all, the storage conditions of aluminum had a rather small influence on adhesion, whereas the composition of the silicone adhesive strongly influences bond strength.
Digitalization changes the manufacturing dramatically. In regard of employees’ demands, global trends and the technological vision of future factories, automotive manufacturing faces a huge number of diverse challenges. Currently, research focuses on technological aspects of future factories in terms of digitalization. New ways of work and new organizational models for future factories have not been described yet. There are assumptions on how to develop the organization of work in a future factory but up to now, literature shows deficits in scientifically substantiated answers in this research area. Consequently, the objective of this paper is to present an approach on a work organization design for automotive Industry 4.0 manufacturing. Future requirements were analyzed and deducted to criteria that determine future agile organization design. These criteria were then transformed into functional mechanisms, which define the approach for shopfloor organization design
Most antimicrobial peptides (AMPs) and their synthetic mimics (SMAMPs) are thought to act by permeabilizing cell membranes. For antimicrobial therapy, selectivity for pathogens over mammalian cells is a key requirement. Understanding membrane selectivity is thus essential for designing AMPs and SMAMPs to complement classical antibiotics in the future. This study focuses on membrane permeabilization induced by SMAMPs and their selectivity for membranes with different lipid compositions. We measure release and fluorescence lifetime of a self-quenching dye in lipid vesicles. Apart from the dose-response, we quantify the strength of individual leakage events, and, employing cumulative kinetics, categorize permeabilization behavior. We propose that differing selectivities in a series of SMAMPs arise from a combination of the effect of the antimicrobial agent and the susceptibility of the membrane (with a given lipid composition) for certain types of leakage behavior. The unselective and hemolytic SMAMP is found to act mainly by the asymmetry stress mechanism, mediated by hydrophobic insertion of SMAMPs into lipid layers. The more selective SMAMPs induced leakage events occurring stochastically over several hours. Lipid intrinsic properties might additionally amplify the efficiency of leakage events. Leakage behavior changes with both the design of the SMAMP and the lipid composition of the membrane. Understanding how leakage behavior contributes to the selectivity and activity of antimicrobial agents will aid the design and screening of antimicrobials. An understanding of the underlying processes facilitates the comparison of membrane permeabilization across in vitro and in vivo assays.
Optofluidics
(2019)
This introduction into the multidisciplinary area of optofluidics offers the necessary foundations in photonics, polymer physics and process analytics to students, engineers and researchers to enter the field. All basic ingredients of a polymer-based platform as a foundation for quick and compact solutions for chemical, biological and medical sensing and manipulation are developed.
An ultraviolet visible (UV–Vis) spectroscopy method was developed that can quantitatively characterize a technical copper surface to determine oxide layers and organic impurities. The oxide layers were produced by a heating step at 175 ℃ for four different times (range = 1–10 min). Partial least squares (PLS) regression was used to establish a relation between the UV–Vis spectra and film thickness measurements using Auger electron spectroscopy depth profiles. The validation accuracy of the regression is in the range of approximately 2.3 nm. The prediction model allowed obtaining an estimation of the oxide layer thickness with an absolute error of 2.9 nm. Alternatively, already known methods cannot be used because of the high roughness of the technical copper surfaces. An integrating sphere is used to measure the diffuse reflectance of these surfaces, providing an average over all angles of illumination and observation.
Palladium-doped silica materials with SiCH3 groups were fabricated by sol-gel method under various calcination atmospheres and membranes were made thereof by coating process. The results showed that air atmosphere can lead to the partial oxidation of metallic Pd0 to PdO while N2 and H2 atmospheres can effectively prevent metallic Pd0 from being oxidized. H2 atmosphere is proved to be a more prominent way to slow down the decomposition of organic SiCH3 group than N2 and air atmospheres. The surface area, micropore volume and porosity of palladium-doped silica membrane material calcined in H2 atmosphere are much higher than those calcined in N2 atmosphere. Compared with N2 atmosphere, the palladium-doped silica membranes calcined in H2 atmosphere showed higher H2 permeability and H2/CO2 selectivity before and after the steam exposure. The apparent activation energy of H2 permeation through the palladium-doped silica membrane calcined under H2 atmosphere (2.51 ± 0.05 kJ/mol) was slightly lower than that calcined under N2 atmosphere (2.84 ± 0.04 kJ/mol). Calcination atmosphere plays some role in membrane performance, which has greater influence on the permeance than on the gas permselectivity. Calcination under H2 atmosphere is well conducive to improve the gas permeance and H2 permselectivity of palladium-doped silica membrane.
Das Essential beschäftigt sich mit der Frage, in welcher Form und in welchem Ausmaß das interne Berichtswesen beabsichtigte und unbeabsichtigte Verhaltenswirkungen bei den Beteiligten auslöst und umgekehrt selbst durch nicht intendiertes Verhalten von Beteiligten in seinen Wirkungen beeinflusst wird. Der Ansatz des „Behavioral Accounting“ wird dabei auf die spezifische Controllingaufgabe des internen Berichtswesens angewendet. Andreas Taschner erläutert, wie Berichte bei Berücksichtigung ihrer direkten und indirekten Wirkungen auf das Verhalten einzelner Betroffener zu einem wirkungsvollen Instrument der Unternehmenssteuerung werden.
Based on a survey among customers of seven German municipal utilities, we estimate hierarchical multiple regression models to identify consumer motivations for participating in P2P electricity trading and develop implications for marketing strategies for this currently relatively unknown product. Our results show a low importance of socio-demographics in explaining differences between consumer groups, but high influence of attitudes, knowledge and likelihood to purchase related products. The most valuable target groups for P2P electricity trading marketing strategies of municipal utilities first and foremost should aim at are innovators, especially prosumers. They are well-informed about and open minded concerning electricity sharing and highly environmentally aware. They ask for transparency and are willing to purchase related products. They are attracted by the ability to share generation and consumption and to a lesser extent by economic reasons. Our results indicate that the marketing efforts should to a special degree take peer effects into account, as they are found to wield great influence on general openness towards and purchase intention for P2P electricity products. Finally, municipal utilities should build on the high level of satisfaction and trust of consumers and use P2P electricity trading as measure to keep and win customers willing to change their supplier.
While the recently emerged microservices architectural style is widely discussed in literature, it is difficult to find clear guidance on the process of refactoring legacy applications. The importance of the topic is underpinned by high costs and effort of a refactoring process which has several other implications, e.g. overall processes (DevOps) and team structure. Software architects facing this challenge are in need of selecting an appropriate strategy and refactoring technique. One of the most discussed aspects in this context is finding the right service granularity to fully leverage the advantages of a microservices architecture. This study first discusses the notion of architectural refactoring and subsequently compares 10 existing refactoring approaches recently proposed in academic literature. The approaches are classified by the underlying decomposition technique and visually presented in the form of a decision guide for quick reference. The review yielded a variety of strategies to break down a monolithic application into independent services. With one exception, most approaches are only applicable under certain conditions. Further concerns are the significant amount of input data some approaches require as well as limited or prototypical tool support.
Die Steigerung der Energieeffizienz ist eine gesellschaftliche Notwendigkeit und bildet neben dem Umstieg auf erneuerbare Energien den entscheidenden Hebel zur Realisierung der Energiewende und Minderung der CO2-Emissionen in Deutschland. Kleine und mittlere Unternehmen (KMU) nehmen in diesem Zusammenhang eine besondere Stellung ein: Aktuelle Studien deuten auf geringere Steigerungsraten der Energieeffizienz gegenüber Großunternehmen hin, die zumeist mit unterschiedlichen materiellen und personalen Voraussetzungen erklärt werden.
Das Forschungsprojekt "Entscheidungen für Energieeffizienz" widmete sich vor diesem Hintergrund der Situation produzierender KMU in Baden-Württemberg. Mit dem Ziel, ein verbessertes Verständnis über die Energieeffizienz-Entscheidungen der KMU zu gewinnen, wurde der Frage nachgegangen, wie der Umgang mit Energie in der täglichen Praxis in KMU organisiert wird, wie über Energieeffizienz entschieden wird und welche Treiber und Hemmnisse sich dabei ergeben.
Zur Beantwortung der Fragen wurde ein Ansatz verfolgt, der kulturelle Einflüsse mitberücksichtigt. Forschungsstrategisch kam ein Mixed-Methods-Ansatz zur Anwendung, der durch die Kombination von qualitativen Daten (Einzelfallstudien) und quantitativen Daten (Fragebogenerhebung) methodisch umgesetzt wurde.
Three established test methods employed for evaluating the abrasion or wear resistance of textile materials were compared to gain deeper insight into the specific damaging mechanisms to better understand a possible comparability of the results of the different tests. The knowledge of these mechanisms is necessary for a systematic development of finishing agents improving the wear resistance of textiles. Martindale, Schopper, and Einlehner tests were used to analyze two different fabrics made of natural (cotton) or synthetic (polyethylene terephthalate) fibers, respectively. Samples were investigated by digital microscopy and scanning electron microscopy to visualize the damage. Damage symptoms are compared and discussed with respect to differences in the damaging mechanisms.
Water jacket systems are routinely used to control the temperature of Petri dish cell culture chambers. Despite their widespread use, the thermal characteristics of such systems have not been fully investigated. In this study, we conducted a comprehensive set of theoretical, numerical and experimental analyses to investigate the thermal characteristics of Petri dish chambers under stable and transient conditions. In particular, we investigated the temperature gradient along the radial axis of the Petri dish under stable conditions, and the transition period under transient conditions. Our studies indicate a radial temperature gradient of 3.3 °C along with a transition period of 27.5 min when increasing the sample temperature from 37 to 45 °C for a standard 35 mm diameter Petri dish. We characterized the temperature gradient and transition period under various operational, geometric, and environmental conditions. Under stable conditions, reducing the diameter of the Petri dish and incorporating a heater underneath the Petri dish can effectively reduce the temperature gradient across the sample. In comparison, under transient conditions, reducing the diameter of the Petri dish, reducing sample volume, and using glass Petri dish chambers can reduce the transition period.
Purpose of the research paper is to illuminate the subject of assortment policy in the German fashion e‐commerce market. A short literature review is conducted in order to set up a system of characteristics to contemplate assortments on a strategic level. In a second step, structured observations are conducted to quantitatively analyze and compare the assortments of the leading online fashion retailers within Germany. Based on literature, the following characteristics for a classification of assortments can be identified: assortment structure, assortment size, assortment width, assortment depth, assortment consistency and rotation, price level, quality mix, fashion degree as well as the mix of private labels and manufacturer brands. Furthermore, the results of the empirical analysis show that there are currently five leaders within the nalyzed market: Amazon, Otto, Zalando, Baur and About You. Among these five market leaders, Amazon positions itself as a retailer that not only offers an enormous assortment size, but also the lowest entry prices as well as the broadest price dispersion. Through the development of the system of characteristics for assortment analysis and the examination of the current market environment, the findings of this paper contribute to the current state of the art in both theoretical and practical aspects.
The promise of immutable documents to make it easier and less expensive for consumers and producers to collaborate in a verifiable way would represent an enormous progress, especially as companies strive for establish service contracts which are based on the flow of many small transactions using machine-to-machine communication. The blockchain technology logs these data, verifies the authenticity and make them available for service offers. This work deals with an architecture enabling to setup order processing between consumers and produceers using blockchain. In this way, the technical feasibility is shown and the special characteristics of blockchain production networks will be discussed.
The sound of brands
(2019)
The aim of this research paper is to both examine and conceptualise the concept of audio branding. Audio branding is an important part of the overall brand management concept and corporate identity. Strong brands ease the choice for customers and convey values and a certain quality promise. Branding is of vital importance. It needs to be acknowledged that only 0.004% of all outer stimuli reach the human consciousness. Therefore, audio branding is a way to further strengthen the overall brand awareness. This leads to an emotional connection with a brand.
This study strives to determine the characteristics of audio branding and to analyse the corporate audio branding of Audi. The result of this research study is the suggestion of the use of audio branding in a way that fits the overall brand picture. Otherwise, the brand communication is inconsistent, and this could lead to a misunderstanding of the brand values for customers. The analysis of the Audi corporate sound design might be beneficial for practitioners. The overall evaluation of the concept of audio branding contributes to the existing body of literature in branding.
Research organisations are not only contributing to sustainable development but also contribute to scientific findings. As key influencers of innovation; employers and publicly funded research organisations not only have the social mandate to deal with their responsibilities regarding the environment and society, but also drive to understand their social responsibility for their employees and the impact on research and operational processes. Sponsored by the German Federal Ministry for Education and Research (BMBF), this paper presents the results of the joint research project; LENA—Guidelines for Sustainability Management and describes how 3 of Germany’s biggest research organisations (Fraunhofer-Gesellschaft, Leibniz Association and Helmholtz Association) face current challenges in human resource management of research organisations by the integration of a common understanding of sustainability and a broad-based framework. The empirical basis is built by a qualitative organisational ethnographical study which reflects the expert knowledge, everyday experiences and the subject-oriented interpretation of sustainability in human resource management. The result derives concrete recommendations for the institutional practice and offers structured and methodologically proven options for action addressing the stakeholders in human resource management in research institutions.