Showing papers by "Münster University of Applied Sciences published in 2020"
TL;DR: In this paper, structural and spectroscopic properties of 1Ln coordination compounds were discussed in detail based on X-ray diffraction measurements, IR spectroscopy, absorption and emission spectrography at 293 and 77 K and theoretical calculations of the intramolecular energy transfer (IET) rates.
30 citations
TL;DR: In this paper, an attempt at ultrashort pulsed laser shock peening with absence of absorptive layer and confining medium which could enhance surface microhardness and the abrasion property of NiTi shape memory alloy was presented.
Abstract: This research paper presents the attempt at ultrashort pulsed laser shock peening with absence of absorptive layer and confining medium which could enhance surface microhardness and the abrasion property of NiTi shape memory alloy. The average roughness values of NiTi specimen were measured on the surface, because the roughness would affect the friction resistance. The microhardness and Young's modulus were investigated at different position of single laser spot by nanoindentation technique. The pin-on-plate sliding abrasion testing were performed with different load-force (0.5 N and 2 N) for different testing time. Results showed that ultrashort pulsed laser shock peening treatment would cause a significant improvement on friction coefficient and abrasion property, which was attributed to the change of surface modification, such as roughness, microhardness, microstructure and titanium oxide layer, but the ultrashort pulsed laser shock peening treatment did not enhance its tensile strength during present research.
29 citations
Posted Content•
TL;DR: This article works out different dimensions that have to be considered for making credit scoring models understandable and presents a framework for making “black box” machine learning models transparent, auditable, and explainable.
Abstract: A major requirement for credit scoring models is to provide a maximally accurate risk prediction. Additionally, regulators demand these models to be transparent and auditable. Thus, in credit scoring, very simple predictive models such as logistic regression or decision trees are still widely used and the superior predictive power of modern machine learning algorithms cannot be fully leveraged. Significant potential is therefore missed, leading to higher reserves or more credit defaults. This paper works out different dimensions that have to be considered for making credit scoring models understandable and presents a framework for making ``black box'' machine learning models transparent, auditable and explainable. Following this framework, we present an overview of techniques, demonstrate how they can be applied in credit scoring and how results compare to the interpretability of score cards. A real world case study shows that a comparable degree of interpretability can be achieved while machine learning techniques keep their ability to improve predictive power.
28 citations
TL;DR: In this paper, a survey data from 98 German strategy executives and performed partial least squares structural equation modeling to study the antecedents and sub-constructs of value proposition innovation (VPI) and found that VPI-based activities regarding new offerings and channels fully mediate the relationship between dynamic capabilities and disruptive innovation.
28 citations
TL;DR: In this paper, the effects of five different enzyme mixtures on the increase in the gas yields of batch AD were investigated, and then the effects on total maximum gas yields and biodegradability were determined on the basis of organic dry matter.
Abstract: The anaerobic digestion (AD) of the organic fractions of solid wastes has been recognized as an economical and highly renewable resource for biogas production. The challenges lie in maximizing the biodegradation of lignocellulose-rich biomasses, which requires effective strategies to prevent the underutilization of feedstocks. Enzymatic treatments for lignocellulosic degradation have huge potential because of their highly versatile and selective compounds. Moreover, such treatments mimic natural processes and require low energy inputs. This study focuses on the batch AD of a variety of lignocellulosic substrates typically used in agriculture, such as silage, straw, and the manure of various animals. The effects of five different enzyme mixtures on the increase in the gas yields of batch AD were investigated. Biogas and methane yields were systematically obtained, and then the effects on total maximum gas yields and biodegradability were determined on the basis of organic dry matter. In almost all the assays between test days 5 and 15, the biodegradability was accelerated, leading to increases of 0.3%–21.1% in methane yields as appropriate to the substrate. However, after 60 days of testing, increases (−2.7%–9.4%) in the total maximum gas yields were not detectable in most cases. It was assumed that the main effects of the enzyme treatments would be faster degradability. Furthermore, the test series with hay and different enzyme dosages showed that a higher dosage does not necessarily result in a higher effect.
27 citations
TL;DR: The importance of university-business cooperation (UBC) continues to grow as mentioned in this paper, however, our understanding of UBC in education is lacking, as is our knowledge of the motivations of academics.
Abstract: The importance of university-business cooperation (UBC) continues to grow. To date, however, our understanding of UBC in education is lacking, as is our knowledge of the motivations of academics. T...
24 citations
TL;DR: The aim is to quantify the available treatment capacities and the energetic potential of waste in Germany and find that in total, almost 320 PJ of end energy are produced in German waste treatment plants: 225 PJ a−1 of heat; and 90 PJ a −1 of electricity.
21 citations
TL;DR: In this article, the three most common approaches currently used to introduce practice in the business curriculum: the case method, internships, and problem-based learning (PBL) are examined in relation to how it incorporates what scholars identify as the four building blocks of a management learning epistemology: (1) ill-defined problems where students execute solutions in real-life (3) in close collaboration with a real organisation, with learning (4) supported by a process of reflection.
19 citations
Posted Content•
Abstract: The importance of university-business cooperation (UBC) continues to grow. To date, however, our understanding of UBC in education is lacking, as is our knowledge of the motivations of academics. This research explores a comprehensive mix of motivations underlying education-driven UBC in the form of student mobility, curriculum design and delivery, and lifelong learning. Specifically, drawing on self-determination theory, motivations across five orientations are examined, namely monetary, career, research, educational and social. Based on an extensive and wide-reaching European survey, this research demonstrates the context-specific nature of academic motivations for UBC in education. Not only do the motivations differ from those commonly noted in relation to commercialisation, the set of motivations varies across different education-driven activities. This research offers important contributions to theory and practice, revealing that academics are motivated more strongly by intrinsic than extrinsic reasons, with only social and educational orientations emerging as significant motivations across all four activities.
18 citations
TL;DR: In this article, the authors survey the knowledge management tools and processes of family businesses and compare theoretical models and their recommendations with the knowledge managements systems, and compare them with knowledge management systems.
Abstract: The aim of this study is to survey the knowledge management tools and processes of family businesses. It compares theoretical models and their recommendations with the knowledge managements systems...
16 citations
TL;DR: Unsteady ventilation is discussed to improve indoor air quality and comfort by simultaneously reducing the energy consumption as mentioned in this paper. But until now, neither any standard system has been established nor are there any design parameters and clear specifications in standards.
TL;DR: In this article, the authors find out how specific leader behaviours of effective family executives and non-family executives may differ, based on Dulewicz and Higgs' broad leadership frame, and draw attention to a large range of behaviours of family-firm executives.
Abstract: Several studies of family firm failures have pointed to non-family members in leading positions as a reason. However, non-family members have often played a key role in family-firm longevity, while non-family executives’ involvement in family firms is increasing. These non-family executives who (co-)run family firms are thought to require an almost impossible set of behavioural qualities. The aim of this exploratory study is to find out how specific leader behaviours of effective family executives and non-family executives may differ.,Based on Dulewicz and Higgs’ (2005) broad leadership frame, the authors draw attention to a large range of behaviours of family-firm executives. In-depth interviews were conducted with successful German executives, both family and non-family ones. Their answers had to contain specific behavioural examples.,More behavioural similarities than differences are shown between family- and non-family-based executives. Yet, the self-reflective communicative behavioural qualities of the non-family executives could balance a lack of such qualities among the family-based executives. Based on the three major differences – decision-making style, communication versatility and self-awareness – specific new research propositions are distilled about effective family firm leadership.,Practical suggestions for recruiting non-family executives are offered. Future quantitative longitudinal research on how to pair specific behavioural qualities of family and non-family based executives that optimise family-firm longevity is urgently needed.
TL;DR: A novel concept for pH sensing is introduced which is specifically adapted to monitor carbonation induced corrosion in concrete structures, based on a ratiometric measurement principle, exploiting the pH sensitive colour switching of thymol blue in the basic pH regime and the emissive properties of two different (Zn)CdSe/ZnS core shell quantum dots.
Abstract: In this communication a novel concept for pH sensing is introduced which is specifically adapted to monitor carbonation induced corrosion in concrete structures. The method is based on a ratiometric measurement principle, exploiting the pH sensitive colour switching of thymol blue in the basic pH regime and the emissive properties of two different (Zn)CdSe/ZnS core shell quantum dots. The transition point of thymol blue in a Hydrogel D4 matrix was determined to be at around pH 11.6, which fits ideally to the intended application. Next to the fundamental spectroscopic characterization of the ratiometric response, a new design for a sensor head, suitable for the incorporation into concrete matrices is presented. Toward this, a manufacturing process was developed which includes the preparation of a double layer of polymers containing either thymol blue or a quantum dot mixture inside a porous ceramic tube. Results of a proof-of-priciple performance test of the sensor head in solutions of different pH and in cement specimens are presented, with encouraging results paving the way for future field tests in concrete.
TL;DR: In this article, the authors evaluated the parameterization of SWMM's permeable pavement module and whether the output is realistic for long-term simulations, particularly for longterm simulations.
Abstract: Limited documentation exists regarding parameterization of SWMM’s permeable pavement module and whether the output is realistic, particularly for long-term simulations. In this paper, we evaluated ...
TL;DR: The Münster wastewater treatment plant (WWTP) is the first municipal WWTP in Germany operating a full-scale membrane contactor system to improve the nitrogen elimination and recovery efficiency as mentioned in this paper.
Abstract:
Membrane contactors are a promising alternative for nitrogen removal and recovery from process water compared to other physicochemical and biological sidestream treatment processes. Münster wastewater treatment plant (WWTP) is the first municipal WWTP in Germany operating a full-scale membrane contactor system to improve the nitrogen elimination and recovery efficiency. Factors influencing the operation and membrane performance are investigated in an accompanying research project. Additional operational aspects of the applied membrane modules are investigated in detail using a bench-scale membrane contactor. First results of the full-scale application demonstrate a high nitrogen removal efficiency of >95%.
TL;DR: In this paper, the authors investigated empirically who is learning, what is learned, and how learning is taking place, based on a Germany-wide survey of 123 community gardens and built a set of respective criteria that helped to demonstrate the high diversity in the learning community, the learning content, and the learning process.
TL;DR: This study documented dismantling efforts at different construction sites and conducted large-scale trials for ETICS waste treatment, which will allow the selection of suitable processing units and will be applied in a model developed by the IWARU Institute to determine economically and ecologically advantageous waste management routes that can be used to handle ETICS Waste in the future.
TL;DR: The authors states that reflection is just as important to learning as action, and that business educators often overlook reflection in their experiential learning activities, e.g., in their workshops.
Abstract: Experiential learning theory states that reflection is just as important to learning as action. However, business educators often overlook reflection in their experiential learning activities, espe...
07 Jan 2020
TL;DR: For university–business cooperation (UBC) to prosper, academics must be sufficiently motivated to undertake different collaborative activities and engage with businesses in various ways.
Abstract: For university–business cooperation (UBC) to prosper, academics must be sufficiently motivated to undertake different collaborative activities and engage with businesses in various ways. Our unders...
30 Oct 2020
TL;DR: This work presents the first generic countermeasure against both REPLY and EFAIL-DE attacks by checking the decryption context including SMTP headers and MIME structure during decryption by seamlessly extends the EFAil-MG countermeasures.
Abstract: OpenPGP and S/MIME are two major standards for securing email communication introduced in the early 1990s. Three recent classes of attacks exploit weak cipher modes (EFAIL Malleability Gadgets, or EFAIL-MG), the flexibility of the MIME email structure (EFAIL Direct Exfiltration, or EFAIL-DE), and the Reply action of the email client (REPLY attacks). Although all three break message confidentiality by using standardized email features, only EFAIL-MG has been mitigated in IETF standards with the introduction of AEAD algorithms. So far, no uniform and reliable countermeasures have been adopted by email clients to prevent EFAIL-DE and REPLY attacks. Instead, email clients implement a variety of different ad-hoc countermeasures which are only partially effective, cause interoperability problems, and fragment the secure email ecosystem. We present the first generic countermeasure against both REPLY and EFAIL-DE attacks by checking the decryption context including SMTP headers and MIME structure during decryption. The decryption context is encoded into a string DC and used as Associated Data (AD) in the AEAD encryption. Thus the proposed solution seamlessly extends the EFAIL-MG countermeasures. The decryption context changes whenever an attacker alters the email source code in a critical way, for example, if the attacker changes the MIME structure or adds a new Reply-To header. The proposed solution does not cause any interoperability problems and legacy emails can still be decrypted. We evaluate our approach by implementing the decryption contexts in Thunderbird/Enigmail and by verifying their correct functionality after the email has been transported over all major email providers, including Gmail and iCloud Mail.
TL;DR: The development of novel or improved photoresponsive materials will have to integrate a careful analysis of the interplay between surface chemistry, surface charges and interaction with the material environment or substrate.
Abstract: The linear photochemical response of materials depends on two critical parameters: the size of the optical band gap determines the onset of optical excitation, whereas the absolute energetic positions of the band edges define the reductive or oxidative character of photo-generated electrons and holes. Tuning these characteristics is necessary for many potential applications and can be achieved through changes in the bulk composition or particle size, adjustment of the surface chemistry or the application of electrostatic fields. In this contribution the influence of surface chemistry and fields is investigated systematically with the help of standard DFT calculations for a typical case, namely composites prepared from ZnS quantum dots and functionalized carbon nanotubes. After comparing results with existing qualitative and quantitative experimental data, it is shown conclusively, that the details of the surface chemistry (especially defects) in combination with electrostatic fields have the largest influence. In conclusion, the development of novel or improved photoresponsive materials therefore will have to integrate a careful analysis of the interplay between surface chemistry, surface charges and interaction with the material environment or substrate.
TL;DR: In this article, a selective activation of TiO2 (anatase) particles encapsulated by Ca- or Sr-polyphosphate is presented, where the highly concentrated cations from seawater, viz. Na+ and Mg2+, displace the Ca2+ or Sr2+ cations.
01 Aug 2020
TL;DR: In this article, the nitrogen vacancy center in diamond can be used to design a simple, small, and robust sensor without employing microwave radiation, which can eliminate the need of an alignment of the magnetic field and still obtain the absolute magnetic density in a single measurement.
Abstract: Magnetic field sensors based on quantum mechanic effects are often
susceptible to misalignments of the magnetic field or need advanced
procedures to compensate for these. Also, the record breaking sensitivities reported for superconducting quantum interference devices and alkali vapor magnetometers come along with large and complex experimental setups. The nitrogen vacancy center in diamond can be used to design a simple, small, and robust sensor without employing microwave radiation. By using compressed nanodiamond particles, it is possible to eliminate the need of an alignment of the magnetic field and still obtain the absolute magnetic flux density in a single measurement. In order to demonstrate the capabilities of this approach, a centimeter-sized modified automotive demo board is employed as a complete sensor with a sensitivity of 78 µT/Wurzel Hz.
29 Oct 2020
TL;DR: In this article, the performance of a rotatable Pitot cylinder probe was experimentally investigated in the calibration test section of a closed loop organic vapor wind tunnel with the working fluid Novec™ 649 at elevated density level.
Abstract: The performance of a rotatable Pitot cylinder probe was experimentally investigated in the calibration test section of a closed loop organic vapor wind tunnel with the working fluid Novec™ 649 at elevated density level. Subsonic up to high subsonic flow conditions (M = 0.5 – 0.7) were covered by the experiments. The data reduction process for obtaining Mach numbers and velocity based on non-ideal flow calculations and corresponding isentropic relations were reviewed. The theoretical results were compared with experimental data. It was found that in the case of high subsonic non-ideal gas flows, significant deviations in comparison with conventional perfect gas flows occurred.
Proceedings Article•
01 Jan 2020TL;DR: This work presents a systematic analysis of the capabilities of malicious office documents, and abuse legitimate features of the OOXML and ODF specifications.
Abstract: OOXML and ODF are the de facto standard data formats for word processing, spreadsheets, and presentations. Both are XML-based, feature-rich container formats dating back to the early 2000s. In this work, we present a systematic analysis of the capabilities of malicious office documents. Instead of focusing on implementation bugs, we abuse legitimate features of the OOXML and ODF specifications. We categorize our attacks into five classes: (1) Denial-of-Service attacks affecting the host on which the document is processed. (2) Invasion of privacy attacks that track the usage of the document. (3) Information disclosure attacks exfiltrating personal data out of the victim’s computer. (4) Data manipulation on the victim’s system. (5) Code execution on the victim’s machine. We evaluated the reference implementations – Microsoft Office and LibreOffice – and found both of them to be vulnerable to each tested class of attacks. Finally, we propose mitigation strategies to counter these attacks.
TL;DR: In this article, the authors developed a multi-step strategy, comprising the definition of a reference process, the derivation of explicit and implicit performance indicators based on either flow meter readings or macroscopic material balances, a verification strategy for experimentally obtained data, and an error consideration, which advices accuracy requirements for analysers and flow meters.
Abstract: The global demand on highly purified gases provided by energy-efficient separation processes grows steadily since decades. An example of particular industrial relevance is nitrogen generated by pressure swing adsorption from compressed air. A kinetically based separation of oxygen from nitrogen is possible by means of carbon molecular sieves (CMS) since oxygen adsorbs remarkably faster in CMS than nitrogen. Even high product purities (5–1000 ppm O2) are easily achievable in commercial generators. However, only a few studies present experimental findings in this purity range. That comes as no surprise, since experimental conditions are not standardised and the determination of N2-PSA performance indicators still creates an experimental challenge. Moreover, the design of the set-up remarkably influences the experimental results. Thus it is the motivation of this study to develop a multi-step strategy, comprising the definition of a reference process, the derivation of explicit and implicit performance indicators based on either flow meter readings or macroscopic material balances, a verification strategy for experimentally obtained data, and an error consideration, which advices accuracy requirements for analysers and flow meters. The effect of cycle time and operating temperature on the performance indicators is exemplarily studied at high purities by means of the proposed strategy.
TL;DR: In this article, the authors demonstrate a technique to empirically estimate the financial costs (or savings) of employing people with disabilities, in order to provide a mechanism for organizations to develop a "business case" for hiring these employees.
Abstract: This paper demonstrates a technique to empirically estimate the financial costs (or savings) of employing people with disabilities, in order to provide a mechanism for organizations to develop a “business case” for hiring these employees. We conducted a utility analysis, a technique common in Human Resources Management (HRM), to illustrate how the financial net value can be calculated based on the difference between service costs and service value. Employment costs include those related to wages, health benefits, pensions, life insurance, vacation pay, training, safety, absences, lateness, turnover, and disability accommodations. Service value estimates are based on wages and are adjusted for performance levels. The data used for our example is drawn from a food services company in Canada. Employees with disabilities in this example provided higher net value to the organization because of their average to above-average performance and lower turnover costs. More importantly, we demonstrate a process that can be used to assess the financial value of hiring workers with disabilities. Given the negative preconceptions often associated with hiring workers with disabilities, this method and example can provide evidence that will be useful for managers and disability advocates for assisting people who wish to join the workforce.