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In this experimental work we present a novel electrolyzer system for the production of hydrogen and oxygen at high pressure levels without an additional mechanical compressor. Due to its control strategies, the operation conditions for this electrolyzer can be kept optimal for each load situation of the system. Furthermore, the novel system design allows for dynamic long-term operation as well as for easy maintainability. Therefore, the device meets the requirements for prospective power-to-gas applications, especially, in order to store excess energy from renewable sources. A laboratory scale device has been developed and high-pressure operation was validated. We also studied the long-term stability of the system by applying dynamic load cycles with load changes every 30 sec. After 80 h of operation the used membrane electrode assembly (MEA) was investigated by means of SEM, EDX and XRD analysis.
Security Analysis of OpenID, followed by a Reference implementation of an nPA-based OpenID Provider
(2017)
CoCoSpot: Clustering and recognizing botnet command and control channels using traffic analysis
(2017)
Improved Plasma Membrane Models as Test Systems for the Membrane
Disrupting Activity of Kalata B1
(2017)
There is a strongly held belief that if companies can direct their marketing activities to improve customer attitudes and intentions, it will impact on purchase behaviors. Departing from complementary yet sometimes conflicting findings of the current literature, we intend to contribute to the literature by answering two related questions. First, we investigate drivers of loyalty intention over time, and by so doing try to better understand loyalty formation. Second, once we understand loyalty formation, we assess the impact of loyalty on different aspects of purchase behavior, considering temporal effects. Therefore, we develop a consumption-system model which assumes that perceptions, intention, and the impact of perceptions and intention on behavior in one period serve as anchors for the same constructs in a subsequent period, implying a pattern of repeated consumption over time.
Using 3SLS regression analysis, results of a large-scale study using survey data from a sample of 2,478 customers from two points in time and purchase data gathered over a 30-month period suggest interesting findings on the two aforementioned questions:
Considering the first question, we find strong support for customer equity drivers directly influencing loyalty. Moreover, we see evidence for loyalty formation as a consumption-system as equity drivers and loyalty intention of one period are significant predictors of the same constructs in the next period.
Addressing the second research question is less straightforward. We find a significant impact of loyalty intention only for purchase frequency, but not for future sales and average receipt. This suggests that in a retailing context, the amount spent depends to a larger extent on actual needs and not on loyalty intention. Loyalty intention seems to be a more appropriate lead indicator for the frequency of store visits. For most categories, repurchase intention will not necessarily be related to higher sales. On the contrary, higher future sales are more likely to depend on the retailer’s ability to cross- and up-sell to its customers. In all, we need to acknowledge that the strongest predictor of future behavior is, in fact, past behavior.
These results question some of the strongly held beliefs of relationship marketing and its impact on actual behavior. Effects might not be as simple as they appear at first, i.e., temporal interplay between constructs. Moreover, it seems that inertia is more important than some marketing research tends to acknowledge. We would therefore suggest a more detailed investigation of customers’ initial choice behavior. If, in fact, inertia is the driving force behind purchase behavior, companies need to augment their emphasis on increasing initial customer contact and, accordingly, on initial product trial. This is somewhat counter-intuitive from a relationship marketing perspective, because that stream of research largely suggests the advantage of retaining customers rather than acquiring new ones. While we are not denying the importance of customer retention, it seems that companies are already fairly successful in doing so – the strong inertia effect confirms that. Hence, customer retention might not be the best strategy to differentiate in the market. Perhaps companies can better differentiate by excelling in customer acquisition. This, however, would have a significant impact on how marketing budgets should be spent by companies trying to reach sustained success. It might be time for re-balancing customer acquisition and customer retention.
Renewable and sustainable energy production by many small and distributed producers is revolutionizing the energy landscape as we know it. Consumers produce energy, making them to prosumers in the smart grid. The interaction between prosumers and other entities in the grid and the optimal utilization of new smart grid components (electric cars, freezers, solar panels, etc.) are crucial for the success of the smart grid. The Power Trading Agent Competition is an open simulation platform that allows researchers to conduct low risk studies in this new energy market. In this work we present Maxon16, an autonomous energy broker and champion of the 2016's Power Trading Agent Competition. We present the strategies the broker used in the final round and evaluate the effectiveness of the strategies by analyzing the tournament's results.
Nach einer erfolgreichen Wiederbelebung der Medieninformatik-Workshopreihe mit dem Workshop Medieninformatik 2016 auf der Mensch-und-Computer 2016 in Aachen, lädt die Fachgruppe Medieninformatik (FG MI) im Fachbereich Mensch-Computer-Interaktion (FB MCI) der Gesellschaft für Informatik (GI) ein zum Workshop Medieninformatik 2017. In diesem Jahr soll es, aufbauend auf den Ergebnissen des 2016er-Workshops, zunächst um das Herausarbeiten von Berufsbildern und Färbungen der Medieninformatik- und Medieninformatik-orientieren Studiengänge gehen. Grundlage der Diskussion ist eine, im Vorfeld des Workshops durchzuführende Kurzumfrage, in der die Zielrichtung der jeweiligen Studiengänge und die Absolventenstatistiken hinsichtlich der Arbeitsfelder erfasst werden. Die Ergebnisse der Befragung werden vor dem Workshop an die Workshop-Teilnehmer zurückgespielt und sollen diesen als Kontext für die Vorbereitung der Workshop-Vorträge dienen. Die Vorträge sollen nach relativ engen Vorgaben die Themen Berufsbilder und Färbungen der Medieninformatik thematisieren, um die Workshopdiskussion anzustoßen. Daran anknüpfend sind die Themen Studiengangsgestaltung (Curriculum) und Erfahrungsaustausch zu (praxisgerechten) Lehr-Lernformen vorgesehen. Des Weiteren soll das im 2016-Workshop sehr kontrovers diskutierte Thema „Gibt es eine Medieninformatik-Forschung?“ anhand konkreter Medieninformatik-Forschungsvorhaben erneut thematisiert werden. Der vorgestellte Themenkanon ist nicht abschließend zu verstehen, sondern soll durch die Teilnehmenden im Vorfeld und vor Ort ergänzt werden.
Global registration of heterogeneous ground and aerial mapping data is a challenging task. This is especially difficult in disaster response scenarios when we have no prior information on the environment and cannot assume the regular order of man-made environments or meaningful semantic cues. In this work we extensively evaluate different approaches to globally register UGV generated 3D point-cloud data from LiDAR sensors with UAV generated point-cloud maps from vision sensors. The approaches are realizations of different selections for: a) local features: key-points or segments; b) descriptors: FPFH, SHOT, or ESF; and c) transformation estimations: RANSAC or FGR. Additionally, we compare the results against standard approaches like applying ICP after a good prior transformation has been given. The evaluation criteria include the distance which a UGV needs to travel to successfully localize, the registration error, and the computational cost. In this context, we report our findings on effectively performing the task on two new Search and Rescue datasets. Our results have the potential to help the community take informed decisions when registering point-cloud maps from ground robots to those from aerial robots.
This paper presents a novel approach to build consistent 3D maps for multi robot cooperation in USAR environments. The sensor streams from unmanned aerial vehicles (UAVs) and ground robots (UGV) are fused in one consistent map. The UAV camera data are used to generate 3D point clouds that are fused with the 3D point clouds generated by a rolling 2D laser scanner at the UGV. The registration method is based on the matching of corresponding planar segments that are extracted from the point clouds. Based on the registration, an approach for a globally optimized localization is presented. Apart from the structural information of the point clouds, it is important to mention that no further information is required for the localization. Two examples show the performance of the overall registration.
Upgrade of Bioreactor System Providing Physiological Stimuli
to Engineered Musculoskeletal Tissues
(2017)
A novel central control interface (CCI) is developed to improve the modular bioreactor system with regard to extendability and modifiability in Tissue Engineering (TE) applications. This paper presents the results developed in the project with open-source hardware and the graphical programming system LabVIEW. A new platform independent User Interface was further developed to contribute to the new flexibility of the device.
Hochdruck PEM-Elektrolyse
(2017)
Performance enhancing study for large scale PEM electrolyzer cells based on hydraulic compression
(2017)
Adhesive organs enable insects to reversibly adhere to substrates even during rapid locomotion. In this process a very fast but reliable change of adhesion and detachment is realised. The stick insect Carausius morosus detaches its adhesive organs by peeling them off the substrate, meaning little areas of the adhesive organs are detached one after another. For such a detachment mechanism low pulling forces are needed. A detachment mechanism as peeling seems also for artificial adhesion devices to be the easiest and the most effortless mechanism for detachment. However, artificial adhesion devices mostly exhibit a solid backing layer preventing effortless peeling. To lift up and detach a small area at the corner of an adhesion device the backing layer has to be tilted, resulting in a deformation of the whole adhesion device, which requires high forces. Subdividing the backing layer into small subunits allows a detachment of a small area at the corner of the adhesion device without deforming the rest of the adhesion device. Thereby, less force is needed to initiate and to complete detachment. To realise an easy detachment of artificial adhesion devices we constructed a holder, which gradually detaches an adhesion device from two sides off the substrate. During normal loading the subunits of the holder interlock with each other so that the pulling force is equally distributed over the whole contact area of the adhesion device ensuring maximal adhesion force. In addition, the holder can be used to increase adhesion during application of the adhesion device. When brought into contact with the substrate with lifted sides, which are lowered subsequently, air trapping is prevented and hence the area of contact can be maximised.
This experimental work deals with the preparation and investigation of PEM fuel cell electrodes, which are obtained using Graphene Related Material (GRM) serving as catalyst support material for platinum nanoparticles. The applied GRM belong to the group of carbon nanofibers and exhibits a helical-ribbon structure with dimensions of 50 nm in diameter and an average length up to a few µm. Furthermore, utilized GRM provide a superior graphitisation degree of about 100 %, which leads to both high corrosion resistance and low ohmic resistance. Material stability plays one of the main roles for long term fuel cell operation, whereby a great electrical catalyst contact combined with high specific surface area yields in high fuel cell performances.
Prior to GRM dispersion and deposition onto a gas diffusion layer, the graphene structures are functionalized by oxygen plasma treatment. Through this step, functional oxygen groups are generated onto the GRM outer surface providing an improved hydrophilic behaviour and facilitating the GRM suspension preparation. In addition, the oxygen groups act as anchors for platinum nanoparticles which are subsequently deposited onto the GRM surface through a pulse electrodeposition process.
Membrane electrode assemblies produced with the prepared electrodes are investigated in-situ in a PEM fuel cell test bench.
This experimental work deals with the preparation and investigation of PEM fuel cell electrodes, which are obtained using Graphene Related Material (GRM) serving as catalyst support material for platinum nanoparticles. The applied GRM belong to the group of carbon nanofibers and exhibits a helical-ribbon structure with dimensions of 50 nm in diameter and an average length up to a few µm. Furthermore, utilized GRM provide a superior graphitisation degree of about 100 %, which leads to both high corrosion resistance and low ohmic resistance. Material stability plays one of the main roles for long term fuel cell operation, whereby a great electrical catalyst contact combined with high specific surface area yields in high fuel cell performances.
Prior to GRM dispersion and deposition onto a gas diffusion layer, the graphene structures are functionalized by oxygen plasma treatment. Through this step, functional oxygen groups are generated onto the GRM outer surface providing an improved hydrophilic behaviour and facilitating the GRM suspension preparation. In addition, the oxygen groups act as anchors for platinum nanoparticles which are subsequently deposited onto the GRM surface through a pulse electrodeposition process.
Membrane electrode assemblies produced with the prepared electrodes are investigated in-situ in a PEM fuel cell test bench.
This work deals with the preparation and investigation of PEM fuel cell electrodes, which are obtained using graphene related material (GRM) serving as catalyst support for platinum nanoparticles. Applied GRM are used for the preparation of suspensions in four distinct mixing ratios. Two sorts of GRM have been investigated: carbon nanofibers (CNF) and graphene oxide (GO). Utilized CNFs provide a superior graphitization degree of about 100%, which leads to both high corrosion resistance and low ohmic resistance in PEM fuel cells.
For electrode preparation a GRM containing layer serving as catalyst support is applied onto a gas diffusion layer (GDL). Prior to GRM suspension and deposition onto a GDL, the graphene structures are functionalized by plasma treatment. Due to this step, an improved hydrophilic behavior for facilitating suspension preparation is achieved. In addition, a subsequent platinum nanoparticle deposition by pulsed electrodeposition process is optimized.
For this study gas diffusion electrodes (GDE) with low platinum loading are prepared for the application as anode in polymer electrolyte membrane fuel cell (PEMFC) systems based on hydraulic compression. As catalyst support material, carbon nanofibers (CNF) are investigated because of their high specific surface area and high graphitization degree. The electrode preparation is optimized by an economic and environmental friendly pre-treatment process in oxygen plasma. For GDE manufacture an ink containing oxygen plasma activated CNFs as well as hydrophilic polymer is used. After spray coating of this CNF ink on a graphitic substrate, platinum is deposited using the pulse plating technique. Preliminary results showed a considerable improvement of CNF dispersibility as well as an increased amount and an optimized morphology of the deposited platinum. Morphology and microstructure are observed by scanning electron microscopy as well as transmission electron microscopy. Platinum loading is determined by thermogravimetric analysis to be in the range of 0.01 mg cm-2 to 0.017 mg cm-2. Furthermore, MEAs are prepared from these GDEs and testing is performed in a novel modular fuel cell test stack based on hydraulic compression. Technical information about stack design and functions is given in this work.
Kurzübersicht der aktuellen Projekte des Westfälischen Energieinstituts.
Intelligenzexplosion
(2016)
The Unfitted Discontinuous Galerkin Method for Solving the EEG Forward Problem: A Second Order Study
(2016)
Biofunktionalisierung von Titanimplantaten mit einem Multilayersystem aus BMP-2 und Fibronektin
(2016)
Nachdem die Fachgruppe Medieninformatik (FG MI) der Gesellschaft für Informatik e.V. (GI) bereits in den Jahren 2009 und 2010 Workshops zu den Themen „Medieninformatik in Forschung, Lehre und Praxis“ (Herczeg 2009) bzw. „Basismodule und Basiscurricula für die Medieninformatik“ (Herczeg 2010) durchgeführt hat und den Input aus den Workshops in der Folge überwiegend im Kreis der FG-Leitung verarbeitet hat, ist es Zeit mit den dort entstandenen Ideen wieder in die größere Runde zu gehen. Dieser Beitrag ist als Diskussionspapier für den kommenden (aber auch für weitere) Workshop(s) im Bereich der Medieninformatik gedacht. Die Ideen stammen im Wesentlichen aus der Arbeit der FG-Leitung bzw. einzelner engagierter Mitglieder der FG MI. Gemäß der Tradition der FG erheben die Darstellungen keinen Richtlinienanspruch, sondern sollen Diskussionen anregen.
A simplified model for spondylodesis, ie fixation of vertebrae by osteosynthesis, is developed for virtual magnetic resonance imaging (MRI) examinations to numerically calculate energy absorption. This paper presents results of calculated energy absorption in body tissue surrounding titanium rod implants. In general each wire or rod behaves like an antenna in electromagnetic fields. The specific absorption rate (SAR) profile describes dependence of implant size. SAR hotspots appear near the rod edges. Depending of the size of implant fixation SAR is 62%(small fixation) up to 90.95%(large fixation) higher than without implants. In addition, local SAR profile displays local dependency on tissue: SAR is lower between the vertebrae.
Thermal Stress at the Surface of Thick Conductive Plates Induced by Sinusoidal Current Pulses
(2016)
Adhesive organs like arolia of insects allow these animals to climb on different substrates by creating high adhesion forces. According to the Dahlquist criterion, arolia must be very soft exhibiting an effective Young's modulus of below 100 kPa to adhere well to different substrates. In previous studies the effective Young´s moduli of adhesive organs were determined using indentation tests yielding their structure to be very soft indeed. However, arolia show a layered structure, thus the values measured by indentation tests comprise the effective Young´s moduli of the whole organs. In this study, a new approach is illustrated to measure the Young´s modulus of the outermost layer of the arolium, i.e. of the epicuticle, of the stick insect Carausius morosus by tensile testing. Due to the inner fibrous structure of the arolium tensile tests allow the characterisation of the overlying epicuticle.
In state of the art polymer electrolyte membrane fuel cells (PEMFC) rare and expensive platinum group metals (PGM) are used as catalyst material. Reduction of PGM in PEMFC electrodes is strongly required to reach cost targets for this technology. An optimal catalyst utilisation is achieved in the case of nano-structured particles supported on carbon material with a large specific surface area. In this study, graphitic material in form of carbon nanofibres (CNFs) is decorated with platinum (Pt) particles serving as catalyst material for PEMFC electrodes with low Pt loading. For electrode preparation CNFs have been previously activated by means of radio frequency induced oxygen plasma. This kind of treatment results in formation of functional groups on the CNF’s surface which directly influences the characteristics of subsequent Pt particle deposition. Different plasma parameters (plasma power, gas flow or exposure time) have to be set in order to achieve formation of oxygen containing functional groups (hydroxylic, carboxylic or carbonylic) on the CNF’s surface. In the frame of this experimental work, electrodes are investigated in respect of optimal morphology, microstructure as well as electrochemical properties. Therefore, samples were characterised by means of scanning electron microscopy combined with energy dispersive X-ray analysis, transmission electron microscopy, thermogravimetry, X-ray diffraction, X-ray fluorescence as well as polarisation measurements.
Platinum is one of the most effective electro catalysts for PEMFCs (proton exchange membrane fuel cells), but because of its prohibitive price, the use of this metal in industrial purposes is limited. As a consequence, during last years, several materials have been investigated, in order to obtain an efficient catalyst for both ORR (oxygen reduction reaction) and HOR (hydrogen oxidation reaction), which can replace the expensive platinum but preserving the same properties: high electrical conductivity, structural stability and good corrosion resistance. Moreover, one of the most important parameters for catalyst materials is the electrochemical surface area (real surface area), which has a strong influence on the reaction rate and also on the current density.
CNFs (carbon nanofibers) are considered to be a promising catalyst support material due to their unique characteristics, excellent mechanical, electrical and structural properties, high surface area and nevertheless, good interaction with platinum particles.
The possibility of preparing CNFs decorated with platinum by electrochemical methods was tested, using a hexachloroplatinic solution bath. The experiments were carried out with the aid of a Potentiostat/Galvanostat MMate 510, in a three – electrode cell.
The aim of the present work was to determine the electrochemical surface area of the CNFs – Pt catalysts, using an electrochemical method. The obtained results correlate very well with the particles size and distribution of platinum, analyzed by SEM (scanning electron microscopy) respectively with the quantity of deposited platinum determined by TG (thermo gravimetrical analyses). Cyclic voltammetry is a suitable method for estimation of the real surface area for catalyst particles.
In polymer electrolyte membrane fuel cells (PEMFC) noble metal nano particles are deposited on graphitic supports serving as electrocatalysts for devices with high power density. In this study anodes are analysed with low platinum loading of about 0.1 mg cm-2. These electrodes are prepared by carbon nano fibres (CNF) decorated with platinum nano particles. For electrode manufacturing two sorts of fibres, which are produced in an industrial scale, are used with different graphitisation degree and surface area. CNF layers are applied on commercially available graphitic substrate by spray coating which leads to a porous structure with high surface area. Subsequently, platinum deposition is achieved by pulsed electroplating for an improved platinum utilisation in PEMFC electrodes. Spray coating and platinum deposition are assisted by a previous oxygen plasma activation process. Prepared anode material is characterised by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), X-ray fluorescence spectroscopy (XRF) and thermogravimetry (TGA). Electrochemical analyses (cyclic voltammetry and corrosion test) are carried out in 0.5 M sulphuric acid. The effect of graphitisation degree of carbon nano fibres on the performance of prepared electrodes is investigated in-situ in a PEM fuel cell test bench.
Im Rahmen eines gemeinsamen Forschungsprojekts mit dem Titel „Energieautarke Bohrlochsensorik mittels Brennstoffzellen – GeoFuelCells“ wurde vom Geothermie-Zentrum Bochum und dem Westfälischen Energieinstitut, unterstützt aus dem Förderprogramm Ziel 2 (2007-2013 EFRE) des Landes NRW, ein brennstoffzellenbasiertes Energieversorgungssystem für Bohrloch-Anwendungen entwickelt.
Im Rahmen der Energiewende ist eine Erweiterung der in das Verbund-netz integrierten Energiespeicher notwendig, um zukünftig die heute gewohnte Versorgungssicherheit trotz eines sehr hohen Anteils volatiler regenerativer Energieerzeugungsanlagen zu ermöglichen. Eine geeignete elektrochemische Methode zur umweltfreundlichen Zwischenspeicherung großer Energiemengen stellt die Wasserelektrolyse mit bedarfsorientierter Rückverstromung dar. Dabei können die dynamischen Einspeise- und Laständerungen im elektrischen Verbundnetz im besonderen Maße von Elektrolyseur- und Brennstoffzellen-systemen auf Basis von Polymer-Elektrolyt-Membranen (PEM) aufgefangen werden.
Bestehende PEM-Systeme sind vor allem in ihrer konstruktiven Zellgröße und ihrer maximalen Leistung bei der Wasserstoffproduktion bzw. der Stromerzeugung stark begrenzt. Vor allem inhomogene Verpressungen großflächiger planarer Zellen in einem klassischen, mechanisch verspannten Stack führen zu hohen Leistungseinbußen. Zudem ergeben sich bei kleinen Stacks aufgrund der geringen Zellspannung ungünstige Wandlungsverhältnisse zwischen Strom und Spannung für eine vor- bzw. nachgeschaltete Leistungselektronik. Ein neuartiges Stackkonzept mit segmentierten Polplatten bietet eine konstruktive Lösung für das Problem größerer aktiver Zellflächen und leistet einen Beitrag zur Entwicklung industriell einsetzbarer Hochdruckelektrolyseure und Brennstoffzellen.
An energy economy with high share of renewable but volatile energy sources is dependent on storage strategies in order to ensure sufficient energy delivery in periods of e.g. low wind and/or low solar radiation. Hydrogen as environmental friendly energy carrier is thought to be an appropriate solution for large scale energy storage. In 2011 the NOW (national organisation for hydrogen in Germany) calculated the demand for hydrogen energy systems as positive (0.8 GW to 5.25 GW) and negative supply for varying power demand (0.68 to 4.3 GW) for the German energy economy in 2025. Due to its dynamic behaviour on load changes polymer electrolyte membrane fuel cells (PEMFC) as well as water electrolyser systems (PEMEL) can play a significant role for large scale hydrogen based storage systems. In this work a novel design concept for modular fuel cell and electrolyser stacks is presented with single cells in pockets surrounded by a hydraulic medium. This hydraulic medium introduces necessary compression forces on the membrane electrode assembly (MEA) of each cell within a stack. Furthermore, ideal stack cooling is achieved by this medium. Due to its modularity and scalability the modular stack design with hydraulic compression meets the requirements for large PEMFC as well as PEMEL units. Small scale prototypes presented in this work illustrate the potential of this design concept.
Für einen Energiesektor, der zukünftig im hohen Maße auf erneuerbaren Quellen beruht, sind Energiespeicher unverzichtbar, um die heute gewohnte Versorgungssicherheit auch in Zeiten geringer Einspeisung aus Wasser, PV- und/oder Windkraftanlagen garantieren zu können. Da konventionelle Speichertechnologien wie beispielsweise Pumpspeicherkraftwerke durch fehlende mögliche Standorte in Deutschland nicht weiter ausgebaut werden, sind Alternativen notwendig. Es ist Konsens, hierfür emissionsarme Strategien zu entwickeln, um die gesetzten Ziele zur Reduktion von CO2 Emissionen zu erreichen. Neben Batterien, die vorzugsweise für Kurzzeitspeicher einzusetzen sind, bietet sich Wasserstoff als umweltfreundlicher Sekundärenergieträger an, der in großen Mengen gespeichert und in Brennstoffzellen mit hohem Wirkungsgrad emissionsfrei in elektrische Energie umgewandelt werden kann. Da elementarer Wasserstoff nicht natürlich vorkommt, ist dieser zuvor zu generieren. Überschüsse aus regenerativen Energiequellen können hierfür ideal genutzt werden. In diesem Beitrag wird ein aussichtsreiches Konzept für einen modularen Hochdruckelektrolyseur vorgestellt, welcher erlaubt, Wasserstoff bei einem hohen Ausgangsdruck bereitzustellen. Durch den prinzipiellen Aufbau, ist ein beliebiges Druckniveau am Ausgang nur von der mechanischen Stabilität der verwendeten Bauteile abhängig. Hierdurch ist es möglich, Wasserstoff direkt in einen Druckgasspeicher oder eine Pipeline zu produzieren, ohne einen zusätzlichen Verdichter nutzen zu müssen. Dies resultiert in signifikanten Kosteneinsparungen und verbessert den Systemwirkungsgrad zukünftiger Anlagen entscheidend.