Refine
H-BRS Bibliography
- yes (1196) (remove)
Departments, institutes and facilities
- Präsidium (397)
- Fachbereich Angewandte Naturwissenschaften (189)
- Fachbereich Informatik (178)
- Fachbereich Wirtschaftswissenschaften (154)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (133)
- Fachbereich Ingenieurwissenschaften und Kommunikation (124)
- Internationales Zentrum für Nachhaltige Entwicklung (IZNE) (100)
- Institut für funktionale Gen-Analytik (IFGA) (72)
- Fachbereich Sozialpolitik und Soziale Sicherung (43)
- Institute of Visual Computing (IVC) (41)
Document Type
- Article (436)
- Part of Periodical (407)
- Conference Object (102)
- Part of a Book (72)
- Report (54)
- Working Paper (42)
- Preprint (19)
- Bachelor Thesis (18)
- Master's Thesis (14)
- Other (10)
Year of publication
Has Fulltext
- yes (1196) (remove)
Keywords
- Hochschule Bonn-Rhein-Sieg (7)
- Machine Learning (7)
- Robotik (7)
- cytokine-induced killer cells (7)
- lignin (7)
- Digitalisierung (6)
- Lignin (6)
- Sustainability (6)
- immunotherapy (6)
- GC/MS (5)
Flüssigkeit, die in Werbespots symbolisch für Menstruationsblut steht, war jahrzehntelang blau, erst im September 2021 zeigte ein Hersteller erstmalig eine Flüssigkeit, welche realitätsnah in der Farbe Rot dargestellt wurde (1). Hygieneartikel, die Menstruierende zwingend benötigen, sind in Deutschland mit wenigen Ausnahmen auf öffentlichen Toiletten nicht verfügbar: Das Nicht-Sichtbarsein offenbarte auch im Jahr 2021 das Tabu um natürliche biologische Prozesse des weiblichen Körpers. Scham und Einschränkungen, die sich verhindern ließen, sind die Folge. Menstruierende werden in ihrem Wohlbefinden limitiert, und negative Erlebnisse führen dazu, dass Betroffene in der Ausübung von sozialen, schulischen und beruflichen Aktivitäten nicht nur durch die Menstruation selbst, sondern auch durch Normen und Erziehungsmuster beeinträchtigt sind, wie zahlreiche internationale Studien gezeigt haben (2). Für den deutschen Hochschulkontext fehlen solche Studien bislang.
Suitability of Current Sensors for the Measurement of Switching Currents in Power Semiconductors
(2021)
This paper investigates the impact of current sensors on the measurement of transient currents in fast-switching power semiconductors in a double pulse test (DPT environment. We review previous research that assesses the influence of current sensors on a DPT circuit through mathematical modeling. The developed selection aids can be used to identify suitable current sensors for transient current measurements of fast-switching power semiconductors and to estimate the error introduced by their insertion into the DPT circuit. Afterwards, this analysis is extended by including further elements from real DPT applications to increase the consistency of the error estimation with practical situations and setups. Both methods are compared and their individual advantages and drawbacks are discussed. Finally, a recommendation on when to use which method is derived.
This paper investigates the effect of voltage sensors on the measurement of transient voltages for power semiconductors in a Double Pulse Test (DPT) environment.We adapt previously published models that were developed for current sensors and apply them to voltage sensors to evaluate their suitability for DPT applications. Similarities and differences between transient current and voltage sensors are investigated and the resulting methodology is applied to commercially available and experimental voltage sensors. Finally, a selection aid for given measurement tasks is derived that focuses on the measurement of fast-switching power semiconductors.
The application of Raman and infrared (IR) microspectroscopy is leading to hyperspectral data containing complementary information concerning the molecular composition of a sample. The classification of hyperspectral data from the individual spectroscopic approaches is already state-of-the-art in several fields of research. However, more complex structured samples and difficult measuring conditions might affect the accuracy of classification results negatively and could make a successful classification of the sample components challenging. This contribution presents a comprehensive comparison in supervised pixel classification of hyperspectral microscopic images, proving that a combined approach of Raman and IR microspectroscopy has a high potential to improve classification rates by a meaningful extension of the feature space. It shows that the complementary information in spatially co-registered hyperspectral images of polymer samples can be accessed using different feature extraction methods and, once fused on the feature-level, is in general more accurately classifiable in a pattern recognition task than the corresponding classification results for data derived from the individual spectroscopic approaches.
Sustainable development needs sustainable production and sustainable consumption. During the last decades the encouragement of sustainable production has been the focus of research and policy makers under the implicit assumption that the observable increasing ‘green’ values of consumers would also entail a growing sustainable consumption. However, it has been found that the actual purchasing behaviour often deviates from ‘green’ attitudes. This phenomenon is called the attitude-behaviour gap. It is influenced by individual, social and situational factors. The main purchasing barriers for sustainable (organic) food are price, lack of immediate availability, sensory criteria, lack or overload of information as well as the low-involvement feature of food products in conjunction with well-established consumption routines, lack of transparency and trust towards labels and certifications.
The phenomenon of the deviation between purchase attitudes and actual buying behaviour of responsible consumers is called the attitude-behaviour gap. It is influenced by individual, social and situational factors. The main purchasing barriers for sustainable (organic) food are price, lack of immediate availability, sensory criteria, lack or overload of information as well as the low-involvement feature of food products in conjunction with well-established consumption routines, lack of transparency and trust towards labels and certifications. The last three barriers are mainly of a psychological nature. Especially the low-involvement feature of food products due to daily purchase routines and relatively low prices tends to result in fast, automatic and subconscious decisions based on a so-called human mental system 1, derived from Daniel Kahneman’s (Nobel-Prize laureate in Behavioural Economics) model in behavioural psychology. In contrast, the human mental system 2 is especially important for the transformations of individual behaviour towards a more sustainable consumption. Decisions based on the human mental system 2 are slow, logical, rational, conscious and arduous. This so-called dual action model also influences the reliability of responses in consumer surveys. It seems that the consumer behaviour is the most unstable and unpredictable part of the entire supply chain and requires special attention. Concrete measures to influence consumer behaviour towards sustainable consumption are highly complex. Reviews of interdisciplinary research literature on behavioural psychology, behavioural economics and consumer behaviour and an empirical analysis of selected countries worldwide with a view to sustainable food are presented. The example of Denmark serves as a ‘best practice’ case study to illustrate how sustainable food consumption can be encouraged. It demonstrates that common efforts and a shared responsibility of consumers, business, interdisciplinary researchers, mass media and policy are needed. It takes pioneers of change who succeed in assembling a ‘critical mass’ willing to increase its ‘sustainable’ behaviour. Considering the strong psychological barriers of consumers and the continuing low market share of organic food, proactive policy measures would be conducive to foster the personal responsibility of the consumers and offer incentives towards a sustainable production. Also, further self-obligations of companies (Corporate Social Responsibility – CSR) as well as more transparency and simplification of reliable labels and certifications are needed to encourage the process towards a sustainable development.
Background: To protect renewable packaging materials against autoxidation and decomposition when substituting harmful synthetic stabilizers with bioactive and bio-based compounds, extracts from Aesculus hippocastanum L. seeds were evaluated. The study objectives were to determine the antioxidant efficacy of bioactive compounds in horse chestnut seeds with regard to different seed fractions, improve their extraction, and to evaluate waste reuse. Methods: Different extraction techniques for field samples were evaluated and compared with extracts of industrial waste samples based on total phenolic content and total antioxidant capacity (2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS)). The molecular weight distribution and absorbance in ultraviolet range (UV) of seed coat extracts were determined, and the possibility of extracts containing proanthocyanidins was examined. Results: Seed coat extracts show a remarkable antioxidant activity and a high UV absorbance. Passive extractions are efficient and much less laborious. Applying waste product seed coats leads to a reduced antioxidant activity, total phenolic content, and UV absorbance compared to the field sample counterparts. In contrast to peeled seed extracts, all seed coat extracts contain proanthocyanidins. Discussion: Seed coats are a potential source of bioactive compounds, particularly regarding sustainable production and waste reuse. With minimum effort, highly bioactive extracts with high potential as additives can be prepared.
This article deals with the under-researched phenomenon of rural health entrepreneurship and its major characteristics. The purpose of this study is to explicate the process of providing health services in rural areas of a developing country and their relation to SDGs. The paper is based on six semi-structured interviews conducted with Serbian health entrepreneurs in rural areas (two private practices, two policlinics, and two dental practices), a review of laws and strategies relevant to the field, and three sessions of discussions with eight experts (four authors and four additional experts). The research methodology follows an empirical, mixed-method case study research procedure. The results are presented in relation to the aspects of frugality, family orientation, and sustainability-oriented innovation. The timeline of the six case studies demonstrates the increasing importance of health entrepreneurs in rural areas due to the aging population and, therefore, increased needs for quality healthcare in these areas. The financing instruments have also become more formal and substantial in recent years, enabling the growth of healthcare businesses in rural areas. However, a major obstacle to further sustainable development remains the non-refundability of services before the state-owned, obligatory health fund, creating major social inequalities, especially in rural areas.
Durch den digitalen Wandel der letzten Jahrzehnte haben sich Fotos im Journalismus zum Must-have entwickelt, gerade online. Doch nicht immer sind Fotos verfügbar, die das Thema eines Artikels dokumentieren können. In dem Fall wird häufig auf Symbolfotos zurückgegriffen. Es finden Fotos Verwendung, die meist auf Vorrat produziert, durch Stockdatenbanken selektiert und präsentiert werden, um schließlich Gesicht eines Produktes oder Artikels zu sein, ohne in ihrer Entstehung mit der Verwendung in Zusammenhang zu stehen.
Welche Wirkung hat die Verwendung von Symbolfotos im Technik- und Wissenschaftsjournalismus auf Rezipienten in Deutschland? Anhand einer explorativen Befragung von 82 Personen mit dem Ziel durch eine vorwiegend quantitative Analyse einen Überblick über Einstellung und Umgang der Stichprobe mit Symbolfotos zu gewinnen, ermöglicht die Arbeit erste Thesen zur Sicht der Rezipienten auf die Verwendung von Symbolfotos – jedoch keine repräsentativen Ergebnisse.
Due to increased emissions of palladium nanoparticles in recent years, it is important to develop analytical techniques to characterize these particles. The synthesis of defined and stable particles plays a key role in this process, as there are not many materials commercially available yet which could act as reference materials. Polyvinylpyrrolidone- (PVP-) stabilized palladium nanoparticles were synthesized through the reduction of palladium chloride by tetraethylene glycol (TEG) in the presence of KOH. Four different methods were used for particle size analysis of the palladium nanoparticles. Palladium suspensions were analyzed by scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), single-particle ICP-MS (SP-ICP-MS), and X-ray diffraction (XRD). Secondary particles between 30 nm and 130 nm were detected in great compliance with SAXS and SP-ICP-MS. SEM analysis showed that the small particulates tend to form agglomerates.
The Report starts with an interview between Eric Bettermann, Director of the German radio station Deutsche Welle, and University President Hartmut Ihne, which deals with responsibility in education and our University’s activities in the area of development cooperation. The chapters “Studies & Research”, “Research”, “Campus” , “The Region and International Issues” cover a wide spectrum of topics that are not rigidly defined because many topics might just as readily be assigned to other chapters.
In the latest edition, some special pages have been dedicated to the topic of “Taking a break”, i.e. to research semesters and sabbaticals, to breaks as a scientific focal point or to absolutely normal coffee breaks. Breaks are an essential part of our lives.
Tamoxifen therapy of invasive breast cancer has been associated with increased levels of endothelin-1 (ET-1) so that an endothelin-1 receptor (ETR) blockade has been suggested as a new therapeutic approach. This study analyzed the relationship between Tamoxifen and ET-1 signalling in invasive breast cancer. Using paraffinized tissue from 50 randomly chosen cases of invasive and in-situ ductal carcinoma from our archive, the expression of ETRs was analyzed by immune histology. ETRs were regularly detectable in normal breast tissue, but rarely in adjacent tumor areas (3/50 cases). By immunoprecipitation, a complex was found consisting of ET-1, estrogen receptors and Tamoxifen. Consequently, transcription of several target genes of ET-1 and estrogen receptors was detectable (interleukin-6, wnt-11 and a vimentin spliceform). In particular, the combination of Tamoxifen, ET-1, and estrogen receptors induced further increasing levels of these target genes. Some of these genes have been found upregulated in metastatically spreading breast cancer cells. We conclude: i) ETRs do not play a role in invasive or in-situ ductal breast cancer; ii) estrogen receptors and Tamoxifen build a complex with ET-1; and iii) upregulated transcription of target genes by ET-1–estrogen receptor–Tamoxifen complex may negatively influence breast cancer prognosis. These results indicate a role for ET-1 in Tamoxifen treated breast cancer patients leading to a potentially worsening prognosis.
Background: the potency of drugs that interfere with glucose metabolism, i.e., glucose transporters (GLUT) and nicotinamide phosphoribosyltransferase (NAMPT) was analyzed in neuroendocrine tumor (NET, BON-1, and QPG-1 cells) and small cell lung cancer (SCLC, GLC-2, and GLC-36 cells) tumor cell lines. (2) Methods: the proliferation and survival rate of tumor cells was significantly affected by the GLUT-inhibitors fasentin and WZB1127, as well as by the NAMPT inhibitors GMX1778 and STF-31. (3) Results: none of the NET cell lines that were treated with NAMPT inhibitors could be rescued with nicotinic acid (usage of the Preiss–Handler salvage pathway), although NAPRT expression could be detected in two NET cell lines. We finally analyzed the specificity of GMX1778 and STF-31 in NET cells in glucose uptake experiments. As previously shown for STF-31 in a panel NET-excluding tumor cell lines, both drugs specifically inhibited glucose uptake at higher (50 μM), but not at lower (5 μM) concentrations. (4) Conclusions: our data suggest that GLUT and especially NAMPT inhibitors are potential candidates for the treatment of NET tumors.
Large display environments are highly suitable for immersive analytics. They provide enough space for effective co-located collaboration and allow users to immerse themselves in the data. To provide the best setting - in terms of visualization and interaction - for the collaborative analysis of a real-world task, we have to understand the group dynamics during the work on large displays. Among other things, we have to study, what effects different task conditions will have on user behavior.
In this paper, we investigated the effects of task conditions on group behavior regarding collaborative coupling and territoriality during co-located collaboration on a wall-sized display. For that, we designed two tasks: a task that resembles the information foraging loop and a task that resembles the connecting facts activity. Both tasks represent essential sub-processes of the sensemaking process in visual analytics and cause distinct space/display usage conditions. The information foraging activity requires the user to work with individual data elements to look into details. Here, the users predominantly occupy only a small portion of the display. In contrast, the connecting facts activity requires the user to work with the entire information space. Therefore, the user has to overview the entire display.
We observed 12 groups for an average of two hours each and gathered qualitative data and quantitative data. During data analysis, we focused specifically on participants' collaborative coupling and territorial behavior.
We could detect that participants tended to subdivide the task to approach it, in their opinion, in a more effective way, in parallel. We describe the subdivision strategies for both task conditions. We also detected and described multiple user roles, as well as a new coupling style that does not fit in either category: loosely or tightly. Moreover, we could observe a territory type that has not been mentioned previously in research. In our opinion, this territory type can affect the collaboration process of groups with more than two collaborators negatively. Finally, we investigated critical display regions in terms of ergonomics. We could detect that users perceived some regions as less comfortable for long-time work.
Population ageing and growing prevalence of disability have resulted in a growing need for personal care and assistance. The insufficient supply of personal care workers and the rising costs of long-term care have turned this phenomenon into a greater social concern. This has resulted in a growing interest in assistive technology in general, and assistive robots in particular, as a means of substituting or supplementing the care provided by humans, and as a means of increasing the independence and overall quality of life of persons with special needs. Although many assistive robots have been developed in research labs world-wide, very few are commercially available. One of the reasons for this, is the cost. One way of optimising cost is to develop solutions that address specific needs of users. As a precursor to this, it is important to identify gaps between what the users need and what the technology (assistive robots) currently provides. This information is obtained through technology mapping.
The current literature lacks a mapping between user needs and assistive robots, at the level of individual systems. The user needs are not expressed in uniform terminology across studies, which makes comparison of results difficult. In this research work, we have illustrated the technology mapping of assistive robots using the International Classification of Functioning, Disability and Health (ICF). ICF provides standard terminology for expressing user needs in detail. Expressing the assistive functions of robots also in ICF terminology facilitates communication between different stakeholders (rehabilitation professionals, robotics researchers, etc.).
We also investigated existing taxonomies for assistive robots. It was observed that there is no widely accepted taxonomy for classifying assistive robots. However, there exists an international standard, ISO 9999, which classifies commercially available assistive products. The applicability of the latest revision of ISO 9999 standard for classifying mobility assistance robots has been studied. A partial classification of assistive robots based on ISO 9999 is suggested. The taxonomy and technology mapping are illustrated with the help of four robots that have the potential to provide mobility assistance. These are the SmartCane, the SmartWalker, MAid and Care-O-bot (R) 3. SmartCane, SmartWalker and MAid provide assistance by supporting physical movement. Care-O-bot (R) 3 provides assistance by reducing the need to move.
This work provides a short but technical introduction to the main building blocks of a blockchain. It argues that a blockchain is not a revolutionary technology but rather a clever combination of three fields: cryptography, decentralization and game theory. In addition, it summaries the differences between a public, private and federate blockchain model and the two prominent consensus mechanism Proof-of-Work (POW) and Proof-of-Stake (POS).
Technik wird in unserer Gesellschaft noch immer mit Männlichkeit assoziiert. Das Bild eines Mannes, der mit einer schweren Bohrmaschine arbeitet, erscheint uns vertrauter als das einer Frau, die dieselbe Tätigkeit ausführt. Derartige Repräsentationen von Technik und Geschlecht werden auch von den Medien verbreitet und könnten so bereits Mädchen und jungen Frauen den Zugang zu Technik erschweren. Digitalisierte Medienwelten bieten allerdings die Möglichkeit, neue Technik-Bilder zu entwerfen und dominante Vorstellungen dadurch zu verschieben. Hier könnten Öffentlichkeiten für Mädchen und Frauen entstehen, die eine Selbstverständigung über technische Interessen und damit einhergehend eine Erfahrung von Kompetenz vermitteln könnten. Anhand von fünf Gruppendiskussionen mit 12- bis 15-jährigen Gymnasiastinnen wurden deren Technikverständnis, deren Nutzung digitaler Medien zu Technikthemen, vor allem aber auch deren Ideen zu einer für sie attraktiven Vermittlung von Technikthemen erfragt. Dabei wurden insbesondere die Vorteile einer symmetrischen Kommunikation im Netz deutlich.
Die allgemeine Konnotation von Technik mit Männlichkeit hat Auswirkungen auf die Berufswahlentscheidungen und das Technikverständnis von jungen Frauen. Nur gut 22 Prozent aller Studierenden in den Ingenieurswissenschaften waren 2014 in Deutschland weiblich (vgl. MonitorING)1. Seit Jahren wird versucht, diese Zahlen nach oben zu korrigieren, indem man Programme für Mädchen und junge Frauen anbietet, die erste Kontakte zu technischen Arbeitsfeldern her stellen. Auch für bereits berufstätige Ingenieurinnen gibt es zahlreiche Förderprogramme, um den Drop-out hochqualiizierter Frauen auf der Karriere leiter zu verhindern. Dennoch verändern sich die prozentualen Anteile von Frauen in ingenieurswissenschaftlichen Studiengängen und Berufen kaum. Aktuelle Studien belegen, dass vor allem kulturell bedingte Erwartungen und Einstellungen hierfür verantwortlich sind (vgl. Paulitz 2012).
Die Digitalisierung und der Einsatz von Informations- und Kommunikationstechnologien (ICT) hat im Arbeits- und Privatleben neben einer höheren Produktivität auch zu neuen Formen von psychischem Stress geführt. Das Stresserleben, das mit dem Einsatz von ICT verbunden ist, wird in der Literatur auch als Technostress bezeichnet. Die Forschung zu diesem Thema zeigt, dass die Entstehung von Technostress von individuellen Faktoren abhängt. Die Persönlichkeit von ICT-Anwenderinnen und Anwendern bestimmt nicht nur das Auftreten von Technostress, sondern hat auch Einfluss auf dessen gesundheitliche und leistungsbezogene Folgen. In diesem Literaturreview wird der Forschungsstand zu der Rolle von Persönlichkeitsunterschieden bei der Entstehung von Technostress und dessen Folgen systematisch zusammengefasst. Die Auswertung der relevanten Forschungsartikel erfolgt hinsichtlich verwendeter Variablen, Stichproben und Studiendesigns, statistischer Methoden, Theorien und Frameworks. Abschließend werden der aktuelle Forschungsstand eingeordnet und Forschungslücken aufgezeigt.
This paper introduces our robotic system named UGAV (Unmanned Ground-Air Vehicle) consisting of two semi-autonomous robot platforms, an Unmanned Ground Vehicle (UGV) and an Unmanned Aerial Vehicles (UAV). The paper focuses on three topics of the inspection with the combined UGV and UAV: (A) teleoperated control by means of cell or smart phones with a new concept of automatic configuration of the smart phone based on a RKI-XML description of the vehicles control capabilities, (B) the camera and vision system with the focus to real time feature extraction e.g. for the tracking of the UAV and (C) the architecture and hardware of the UAV.
In this work, the surface reactions of the homemade explosive triacetone triperoxide on tungsten oxide (WO3) sensor surfaces are studied to obtain detailed information about the chemical reactions taking place. Semiconductor gas sensors based on WO3 nanopowders are therefore produced and characterized by scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. To analyze the reaction mechanisms at the sensor surface, the sensor is monitored online under operation conditions using Raman spectroscopy, which allows to identify the temperature-dependent sensor reactions. By combining information from the Raman spectra with data on the changing resistivity of the underlying semiconductor, it is possible to establish a correlation between the adsorbed gas species and the physical properties of the WO3 layer. In the results, it is indicated that a Lewis acid–base reaction is the most likely mechanism for the increase in resistance observed at temperatures below 150 °C. In the results, at higher temperatures, the assumption of a radical mechanism that causes a decrease in resistance is supported.
Solid-Phase Microextraction (SPME) is a very simple and efficient, solventless sample preparation method, invented by Pawliszyn and coworkers at the University of Waterloo (Canada) in 1989. This method has been widely used in different fields of analytical chemistry since its first applications to environmental and food analysis. SPME integrates sampling, extraction, concentration and sample introduction into a single solvent-free step. The method saves preparation time, disposal costs and can improve detection limits. It has been routinely used in combination with gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) and successfully applied to a wide variety of ompounds, especially for the extraction of volatile and semi-volatile organic compounds from environmental, biological and food samples.
Since the last twenty years, SPME in headspace (HS) mode is used as a valuable sample preparation technique for identifying degradation products in polymers and for determination of rest monomers and other light-boiling substances in polymeric materials. For more than ten years, our laboratory has been involved in projects focused on the application of HS-SPME-GC/MS for the characterization of polymeric materials from many branches of manufacturing and building industries. This book chapter describes the application examples of this technique for identifying volatile organic compounds (VOCs), additives and degradation products in industrial plastics, rubber, and packaging materials.
Advocates of autonomous driving predict that the occupation of taxi driver could be made obsolete by shared autonomous vehicles (SAV) in the long term. Conducting interviews with German taxi drivers, we investigate how they perceive the changes caused by advancing automation for the future of their business. Our study contributes insights into how the work of taxi drivers could change given the advent of autonomous driving: While the task of driving could be taken over by SAVs for standard trips, taxi drivers are certain that other areas of their work such as providing supplementary services and assistance to passengers would constitute a limit to such forms of automation, but probably involving a shifting role for the taxi drivers, one which focuses on the sociality of the work. Our findings illustrate how taxi drivers see the future of their work, suggesting design implications for tools that take various forms of assistance into account, and demonstrating how important it is to consider taxi drivers in the co-design of future taxis and SAV services.