Die 20 zuletzt veröffentlichten Dokumente
STEPsCON 2018 was jointly organized by the Faculty of Applied Natural Sciences of TH Köln (Germany) and the University of Oulu (Finland) on the occasion of the 50th anniversary of the Leverkusen – Oulu town twinning. The conference focused on sustainability issues and covered the current state of research in four key topics:
1. Sustainable Medicine and Pharmaceuticals
2. Resources and Bioremediation
3. Sustainable Chemistry & Industrial Biotechnology
4. Innovative Materials & Formulations
For use in a landfill, a laboratory reactor for safe and environmentally friendly biological utilization of low-concentration methane gas will be further developed. The current principle of denitrification-coupled aerobic methane oxidation will be replaced by methane oxidation under anaerobic conditions. Anaerobic methane oxidation offers the advantage that, in addition to methane, nitrate also undergoes biodegradation. Another advantage is that the oxygen content can be significantly lower. This reduces the risk of the formation of an explosive atmosphere in the reactor. Currently, the principle of anaerobic methane oxidation is known. However, organisms capable of doing so are not yet available as a pure culture. Therefore, several biomasses were probed for the ability of anaerobic methane oxidation. It was found that moor-heavy sediment, activated sludge from the leachate treatment plant and biomass from the local biogas plant oxidize methane after the natural carbon source (C source) was been removed.
The synthesis of 17-hydroxy-oleic acid based oligomeric esters was investigated with immobilized Pseudozyma antarctica Lipase B and hexanediol as co-substrate. The effects of different reaction parameters on velocity and product composition at equilibrium conditions were analyzed. The synthesis of oleic acid esters was used as a reference system for initial evaluation of reaction parameters. The reaction with oleic acid and hexanediol was fastest at an enzyme concentration of 5% at 60 °C and high conversions of > 90 % were achieved in non-polar solvents in the presence of molecular sieves. In heptane an oleic acid conversion of 96 % was reached with a final diester to monoester ratio of > 4:1. In syntheses trials with 17-hydroxy-oleic acid the formation of oligomers was verified with GPC, however; conversion was generally lower than with oleic acid. Removal of hydroxyl fatty acid monomers and dimers and the formation ester functionalities could be verified by GC analysis. An increase of the degree of oligomerization was observed simultaneously by GPC analysis. The number-average molecular weight was around 1400 in the best trials corresponding to a degree of oligomerization of around 4 units of hydroxyl-fatty acid attached to a hexanediol core. Though transformations were not complete, the final oligomer size was in the lower range of polyester diols used for polyurethane manufacturing.
Due to the worldwide shortage of petrochemical based resources, the usage of renewable bio-based raw materials for established and novel products becomes increasingly important.[1] Such bio-based resources are already used for the fabrication of a variety of products, e. g. paper, lubricants, detergents or cosmetics. In the future they are expected to emerge in many more applications in industry and household.[1]
A very promising approach relies on the use of glycolipids as a source of hydroxy-oleic acid.[2] Microbial glycolipids are produced for instance via fermentation from natural resources such as plant oils and sugar.[3] After fermentation complex product mixtures are obtained with the composition depending on the microorganism, substrate and fermentation time.[3] The successful use of microbial glycolipids and hydroxy-oleic acid (HOA) derived therefrom as bio-based intermediates requires reliable analytical methods as well as robust manufacturing processes for the synthesis and cleavage of bio-based molecules. In order to obtain hydroxy-oleic acids as bio-based intermediates, the acidic cleavage of microbial derived sophorolipid was investigated. In addition the implementation of HOA in polyurethane (PU) systems was explored.
The introduction of Feed-in tariffs in the German Renewable Energy Act (EEG) fuelled the growth of anaerobic digestion (AD) industry making Germany the country with highest number of operational AD plants. However, the rapid expansion of AD industry resulted in some unwanted side-effects such as food vs fuel debate, increased prices for electricity and the temporal mismatch between supply and demand of electricity grid. Subsequent amendments in EEG has tried to address some of these issues by reduction in Feed-in tariffs, introduction of a cap on cereal based feedstocks and providing premium for energy production in accordance with market demand. Furthermore, the Feed-in tariffs which were introduced for 20 years are soon going to expire. The changes in legal and political discourse is soon going to introduce some new challanges to the AD industry. This paper has discussed some of these challanges and their potential solutions.
The electricity network is undergoing a change due to reducing costs for renewable energy sources. Subsidy programs for renewable energy sources are changing and the funding available is being reduced. This will have an impact on anaerobic digestion which in some cases may struggle financially. Overfeeding is one of the most common mechanisms of inhibition in the process, and by shifting to intermittent feeding for on-demand production, this change will provide more information about the digestion process and could be used to detect the beginning of inhibition due to overfeeding. This paper discusses the shift towards intermittent production and how this change can be used to monitor the anaerobic digestion process.
Comparative analysis of non-natural acceptor glucosylation with sucrase enzymes of family GH 70
(2019)
Mutan- and alternansucrase were analyzed for their non-natural glucosylation potential with catecholic compounds caffeic acid and nordihydroguaiaretic acid (NDGA) as well as with non-catecolic p-coumaric acid and umbellic acid. Mutansucrase accepted both catecholic substrates and high glucosylation yields of 92 % with caffeic acid and 81 % with NDGA were obtained. The enzyme showed a clear regio-preference for the catechol 4-OH, which corresponds to findings from our previous work with Leuconostoc and Weissella derived glucansucrases. The substrate spectrum of the alternansucrase was broader and all substrates were successfully glucosylated with a preference for the catechols. Interestingly alternansucrase possessed a different regio-specificity. With caffeic acid the 3-O-α-D-glucoside was the major product. A similar substrate spectrum and regioselectivity pattern was observed in previous glucansucrase screenings only with glucansucrase from strain Weissella beninensis DSM 22752. Therefore it may be concluded that the W. beninensis enzyme is an alternansucrase type enzyme as well.
In the degradation of ammonia (NH4+) to gaseous nitrogen (N2), the nitrification is one of the two reaction steps. The nitrification itself is divided in two steps and is performed by two different types of bacteria. Current literature has shown that there are types of bacteria, which have the genetic equipment to perform both steps in one bacteria. Nevertheless, in wastewater and landfill leachate treatment, ammonia-oxidizing organisms (AOO) and nitrite-oxidizing organisms (NOO) occur as a symbiosis. The intermediate of the two consecutive reaction steps (NO2-, nitrite) is toxic. For this reason, both steps are necessary for the two bacterial groups. To determine the ratio of AOO, NOO and heterotrophic bacteria (which use organic compounds as carbon and energy source) the oxygen uptake rate (OUR) with selective inhibition with N-allylthiourea (ATU) and azide is used. In the inflow of a pilot plant in one street a step by step increased amount of a process water out of a fermentation plant was added to the landfill leachate. For comparison, the other street was supplied only with landfill leachate with the same amount of nitrogen. As a result, comparable values for the different bacterial groups and reproducible results were measured and lead to a better understanding of the analysed nitrification sludge. Deeper understanding of the behavior of the different groups will result in a reduce risk of malfunctions and a more stable operation in the wastewater or landfill leachate treatment plant.
The whole site of the waste disposal centre Leppe in Lindlar has been modified by the project :metabolon into an authentic learning site for knowledge transfer. Addressing all age groups, the project offers insights into environmental knowledge and explains contexts of resources and material flows. The site conditions allow practical outlooks on future energy systems. Following the meta theme of “lifetime learning”, pupils and students are addressed by different modules, considering their individual learning levels.
Aerobic microbial cultivations are industrially important group of processes and pose challenges for the reactor design. In particular, estimation of industrial scale conditions is difficult from laboratory and pilot scale data. Due to complex interaction of gas/liquid phase hydrodynamics, mass transfer parameters and microbial metabolism, both improvement of modelling tools and reactor design are desired. We present an approach to estimate growth conditions in industrial scale reactor by combining black-box metabolic models with CFD-model.
The reactor type used here is Outotec OKTOP9000®, which is used in the industrial hydrometallurgical processes at 900 m3 scale. It is adopted to a laboratory setting and compared to stirred tank reactor (STR) in gas dispersion, mass transfer and yeast cultivation experiments. In addition, a kinetic model for the yeast growth is developed based on literature sources and validated by the laboratory scale batch cultivations. This kinetic model is used along with CFD-model that is developed to describe the flow and mass transfer conditions in the industrial scale reactor.
The laboratory scale experiments show the feasibility of OKTOP9000® reactor when compared to STR, particularly with improved gas handling capacity. The modelling approach shows qualitatively similar behavior in the large scale simulations when compared to laboratory scale cultivations.
Before transporting the landfill leachate to municipal wastewater treatment plant it has to be treated in a landfill leachate treatment plant, as it comprises high concentrations of ammonium. The elimination of ammonium load in the leachate is usually done by the combined processes of nitrification and denitrification with a specially adapted biocenosis in the activated sludge (AS). For each of the steps, specialized bacteria such as Nitrosomonas, Nitrobacter and Paracoccus are used to transfer the ammonia to gaseous nitrogen. The aim of this investigation was to find suitable process parameters for a complementary treatment of fermentation water from a biogas plant together with landfill leachate. The processed water of the biogas plant consists of a higher concentration of ammonium and carbon sources or easily degradable volatile fatty acids. It can save the usage of external carbon source (acetic acid) and additionally it could also compensate the missing volumes of leachate in times of low rain and low leachate flows. To maintain the high workload for the existing leachate treatment pilot plant (LTPP), a combined treatment of landfill leachate and process water is also of economic and of ecological interest. The long-term adaption process of the biocenosis needs to be done step-by-step. Innovative process monitoring is needed to prevent biocenosis collapse. In our study, we present our set-up, a closer look at the ongoing experiment and the long-term changes in the biocenosis.
Pseudozyma antarctica Lipase B catalyzed esterification and transesterification in deep eutectic solvents (DES) was investigated in reaction systems with alcohols of different polarity. Coconut oil and crude biodiesel were deacidified successfully with non-immobilized CALBL and final acid values of 1.2 for biodiesel and 0.5 for coconut oil were obtained, while no esterification with ethanol was observed without DES. Water depletion of the lipid phase in the presence of water adsorbing DES causes this difference. Analysis of water contents revealed a 10 fold lower water content of the lipid phase in the presence of a second DES phase than in trials without utilization of DES. In contrast reactions of hydrophilic polyols are suppressed in the presence of DES. While the esterification of fructose and the transesterification with glycerol worked well in the polar solvent 2-methyl-2-butanol, almost no fructose esterification and a decreased transesterification with glycerol were observed in the presence of DES. Analysis of logP values of the substrates explains the substrate dependent differences in reactivity. The polar alcohols are probably bound strongly in the hydrogen-bonding network of the DES phase and are thus not available for lipase catalyzed reactions.
Modern industrial biomass combustion plants are regulated by the power and/or combustion control. In this process, the implemented sensors collect the relevant measured data. The aim is to achieve ideal combustion with optimum efficiency and to minimize gas emissions. For this purpose, a group within the research project Metabolon developed new regulatory procedures in order to record the combustion process of a biomass combustion plant using a webcam. The recordings were evaluated automatically and were used for a better monitoring of the process. In addition, the webcam-based method aims, among other things, to provide private homes with a cost-effective variant as an alternative to industrial system solutions.
In the last few decades raw material molasses, used in large scale fermentations in the production of bioethanol, citric acid, (baker´s) yeast and yeast extracts, has become more and more expensive. That is why agro-industrial wastes have become an interesting alternative. They are being produced in large volumes every day and represent a serious environmental problem considering its high organic content. The present contribution aims to demonstrate how waste products of wine production can be employed as substrate in bioethanol production. Cultivation of yeast and bioethanol production on molasses and grape pomace extract was studied in flasks in laboratory scale. This work should be regarded as an example of integrated sustainability which demonstrates how the waste from one industrial process is used as feedstock for another.
Virtual Reality (VR), Augmented Reality (AR) und Mixed Reality (MR) stoßen als innovative Technologien inzwischen auf breites öffentliches Interesse. Unter dem neuen Oberbegriff Cross Reality (XR) erreichen Anwendungen von VR, AR als auch MR dabei zusehends eine größere Zielgruppe – sowohl im B2B als auch im B2C-Segment. XR-Technologie ist nicht mehr nur Spezialisten vorbehalten, sondern hält Einzug in Industrie, Kreation und Entertainment: mit 360-Grad-Videos und VR-Games, beim Produktdesign, als Hilfe bei Orientierung im Raum, für Trainingssimulationen und virtuelle Konferenzen. Die Struktur und Entwicklung dieser noch jungen, sich dynamisch entwickelnden Branche untersucht diese Studie. Die XR-Branche in NRW besteht aus 134 Akteuren. Die meisten Unternehmen haben Ihren Sitz in Köln und die wichtigsten Zielbranchen sind Medien/Information/Kommunikation und das Verarbeitende Gewerbe. In der Branche herrscht eine positive Stimmung und eine schnelle Internetverbindung sowie die Verfügbarkeit von technischen Mitarbeitern sind die wichtigsten Standortfaktoren.
Die Funktionsfähigkeit der öffentlichen Verwaltung ist auch und gerade bei einem Ausfall oder einer Beeinträchtigung Kritischer Infrastrukturen notwendig für die Aufrechterhaltung der Gesellschaft und des Staates. Ausgehend von dieser These wird zwischen Dezember 2018 und Februar 2019 eine Umfrage in den Landkreisen, Städten und Gemeinden des Regierungsbezirks Stuttgart durchgeführt. In ihr wird der Vorbereitungsgrad der öffentlichen Verwaltung hinsichtlich einer Versorgungsmangellage erfasst. Dabei wird ausschließlich die Versorgung des Personals innerhalb der Verwaltungseinrichtung betrachtet. Es wird untersucht, ob Vorsorgemaßnahmen für die Bereiche Trinkwasser, Nahrungsmittel, beheizte und beleuchte Räumlichkeiten, Sanitäranlagen, Ruhe- und Schlafmöglichkeit sowie Bargeld für die Gehälter der Mitarbeitenden getroffen sind. Als Vorsorgemaßnahmen werden generelle Planungen, Vorräte und Rahmenverträge mit Privatunternehmen betrachtet. Die Antworten werden von den Umfrageteilnehmenden hinsichtlich ihrer zeitlichen Auslegung eingeordnet. Zusätzlich werden die Teilnehmenden zu Planungsgrundlagen, Verbesserungspotenzial und einer Einschätzung der eigenen Vorbereitungen befragt. Diese Bachelorarbeit wertet die Umfrageergebnisse aus. Die Antworten zeigen, dass rund die Hälfte der Befragten eine Notstromversorgung besitzt und rund jede fünfte Einrichtung Planungen für die Trinkwasserversorgung der Mitarbeitenden vorhält. Darüber hinaus sind Vorbereitungen zur Versorgung des Personals nur vereinzelt vorhanden. Spezifische Vorräte für einen Ausfall der Versorgungsleistungen sind nur bei wenigen Befragten in geringem Maße vorhanden. Dennoch zeigt sich durch Alltagsvorhaltungen eine Latenzzeit bis zum Funktionsausfall. Rahmenverträge zur redundanten Sicherstellung der Versorgung sind nur selten abgeschlossen. Die Befragten geben an, dass sie für die Bearbeitung der Thematik Bedarf an weiteren Hilfestellungen haben. Die bekannten Schutzniveaus 72 Stunden (Notstromversorgung) und 14 Tage (Notvorräte der Bevölkerung) sind nicht oder nur sehr bedingt auf den Sektor Staat und Verwaltung zu übertragen. In der Auswertung der Ergebnisse werden drei Möglichkeiten identifiziert, um den Vorbereitungsgrad zu optimieren: Die Erhöhung der Vorhaltungen, das Optimieren der Planungen und das Abschließen von Rahmenverträgen. Darüber hinaus sind langfristig und einrichtungsunabhängig die derzeitigen Zuständigkeiten zu prüfen, einheitliche Schutzniveaus zu etablieren sowie eine gesellschaftliche und politische Kommunikationskultur hinsichtlich der Risiken eines Ausfalls oder einer Beeinträchtigung Kritischer Infrastrukturen aufzubauen.
Die vorliegende Arbeit beschäftigt sich im übergeordneten Kontext mit den Bounding Volume Hierarchies zur Veinfachung des Intersection Testings beim Raytracing. Die derzeitige Problematik besteht vor allem in der immer noch zu optimierenden Laufzeit. Dementsprechend wird trotz der bereits bestehenden Beschleunigungsdatenstrukturen wie unter anderem der Bounding Volume Hierarchy versucht, effizientere Strukturen oder Erstellungsprozeduren zu entwickeln. Für die Bounding Volume Hierarchy bedeutet dies, dass vor allem hinsichtlich verschiedener Splitting-Methoden und Möglichkeiten für die Baumoptimierung geforscht wird. Explizit wird daher innerhalb dieser Arbeit untersucht, wie die Bounding Volume Hierarchy durch die Verwendung der Hauptkomponentenanalyse bei der Erstellung optimiert werden kann und wie effizient der daraus resultierende Ansatz gegenüber der klassischen Bounding Volume Hierarchy sowie deren Splitting-Methoden ist. Eine Evaluation anhand 12 verschiedener Szenen zeigte, dass der vorliegende Ansatz unter Verwendung der SAH-Methode wie auch mit der Middle-Methode 17.70% respektive 13.14% geringere Renderlaufzeiten als der distanzbasierte Ansatz aufweist. Des Weiteren konnte mittels der kombinierten Verwendung aus klassischer SAH-Methode und PCA-basierter SAH-Methode eine weitere Verbesserung um 6.65% gegenüber der SAH-Methode der PCA-BVH erreicht werden.
Aufgrund ihrer aktuellen Bedeutung im Zusammenhang des Internet of Things werden in der vorliegenden Arbeit Time Series Databases und Event Stores miteinander vergli-chen. Ziel ist, die Gemeinsamkeiten und Unterschiede der beiden Arten von Datenbank Management Systemen herauszustellen.
Der erste, theoretische Teil des Vergleichs erfolgt anhand der funktionalen Kriterien Speichersystem, Performance und Funktionen sowie der nicht-funktionalen Kriterien Usability und Support. Im zweiten Teil des Vergleichs wird anhand eines konkreten An-wendungsfalls untersucht, ob sich Time Series Databases und Event Stores gleicher-maßen für die Speicherung und in einem zweiten Schritt für die Abfrage von Zeitreihen-daten eignen.
Zumal der theoretische Vergleich Unterschiede zwischen einzelnen Time Series Data-bases und Event Stores in Bezug auf die betrachteten Kriterien erkennen lässt, wird für den praktischen Vergleich unter Berücksichtigung der im konkreten Anwendungsfall gegebenen Anforderungen nur die am besten geeignetste Time Series Database (In-fluxDB) und der am besten geeignetste Event Store (Event Store) ausgewählt. Der prak-tische Vergleich zeigt, dass die Zeitreihendaten im konkreten Anwendungsfall zwar in beiden Arten von Datenbank Management Systemen gespeichert werden können, die Nutzung der auf Zeitreihendaten spezialisierten Time Series Database InfluxDB jedoch offensichtliche Vorteile gegenüber dem Event Store aufweist.
In diesem Jahresbericht dokumentiert die Kölner Forschungsstelle Rückversicherung ihre
wissenschaftlichen Forschungsprojekte, Publikationen, Vorträge und Veranstaltungen in 2017, um dadurch gegenüber den Freunden und Förderern der Forschungsstelle Rechenschaft über die geleistete Forschungsarbeit abzulegen.
The southeast of Córdoba province used to be originally covered by hundreds of wetlands that got heavily modified or drained in the last few decades. Since wetlands provide various important ecosystem services (ESS) for human well-being, their degradation created several problems in La Picasa basin, among which floods are the most obvious one. The wise use of wetlands is increasingly acknowledged to be part of nature-based solution approaches reducing disaster risk. However, in the study area these approaches remain a relatively new concept to decision makers and the lack of knowledge on their effectiveness and implementation process poses a serious barrier to their adoption.
To overcome this obstacle, this dissertation applies an ESS perspective on the current problems of La Picasa basin and sets it in a context of socio-ecological system (SES) theory. A comprehensive analysis of (1) the role wetlands have played in the historic development of the SES, (2) important stakeholder dynamics that create opportunities or restrictions for the conservation of wetlands and (3) possible management approaches to inverse negative ESS trade-offs and feedback loops, was performed.
Results demonstrate that the current problems of floods have both natural and anthropogenic causes. In this regard, wetlands hold a vital role in the complex historic interactions between the social and ecological drivers of changes in the water balance. Although a social network between stakeholders exists, several conflicts prevent a proper functioning of a basin-wide integrated management concept based on wetland restoration. Nature-based solution approaches, putting wetlands in the center of attention of future management strategies, were found to hold a high potential to reduce the risk of floods and, as a side-effect boost biodiversity and habitat quality in the study area.