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For fuel flexibility enhancement hydrogen represents a possible alternative gas turbine fuel within future low emission power generation, in case of hydrogen production by the use of renewable energy sources such as wind energy or biomass. Kawasaki Heavy Industries, Ltd. (KHI) has research and development projects for future hydrogen society; production of hydrogen gas, refinement and liquefaction for transportation and storage, and utilization with gas turbine / gas engine for the generation of electricity. In the development of hydrogen gas turbines, a key technology is the stable and low NOx hydrogen combustion, especially Dry Low Emission (DLE) or Dry Low NOx (DLN) hydrogen combustion. Due to the large difference in the physical properties of hydrogen compared to other fuels such as natural gas, well established gas turbine combustion systems cannot be directly applied for DLE hydrogen combustion. Thus, the development of DLE hydrogen combustion technologies is an essential and challenging task for the future of hydrogen fueled gas turbines. The DLE Micro-Mix combustion principle for hydrogen fuel has been in development for many years to significantly reduce NOx emissions. This combustion principle is based on cross-flow mixing of air and gaseous hydrogen which reacts in multiple miniaturized “diffusion-type” flames. The major advantages of this combustion principle are the inherent safety against flashback and the low NOx-emissions due to a very short residence time of the reactants in the flame region of the micro-flames.
The energy-efficiency of technical systems can be improved by a systematic design approach. Technical Operations Research (TOR) employs methods known from Operations Research to find a global optimal layout and operation strategy of technical systems. We show the practical usage of this approach by the systematic design of a decentralized water supply system for skyscrapers. All possible network options and operation strategies are modeled by a Mixed-Integer Nonlinear Program. We present the optimal system found by our approach and highlight the energy savings compared to a conventional system design.
New information regarding the influence of a stepped chute on the hydraulic performance of the United States Bureau of Reclamation (Reclamation) Type III hydraulic jump stilling basin is presented for design (steady) and adverse (decreasing tailwater) conditions. Using published experimental data and computational fluid dynamics (CFD) models, this paper presents a detailed comparison between smooth-chute and stepped-chute configurations for chute slopes of 0.8H:1V and 4H:1V and Froude numbers (F) ranging from 3.1 to 9.5 for a Type III basin designed for F = 8. For both stepped and smooth chutes, the relative role of each basin element was quantified, up to the most hydraulic extreme case of jump sweep-out. It was found that, relative to a smooth chute, the turbulence generated by a stepped chute causes a higher maximum velocity decay within the stilling basin, which represents an enhancement of the Type III basin’s performance but also a change in the relative role of the basin elements. Results provide insight into the ability of the CFD models [unsteady Reynolds-averaged Navier-Stokes (RANS) equations with renormalization group (RNG) k-ϵ turbulence model and volume-of-fluid (VOF) for free surface tracking] to predict the transient basin flow structure and velocity profiles. Type III basins can perform adequately with a stepped chute despite the effects steps have on the relative role of each basin element. It is concluded that the classic Type III basin design, based upon methodology by reclamation specific to smooth chutes, can be hydraulically improved for the case of stepped chutes for design and adverse flow conditions using the information presented herein.
Background
Culture media containing complex compounds like yeast extract or peptone show numerous disadvantages. The chemical composition of the complex compounds is prone to significant variations from batch to batch and quality control is difficult. Therefore, the use of chemically defined media receives more and more attention in commercial fermentations. This concept results in better reproducibility, it simplifies downstream processing of secreted products and enable rapid scale-up. Culturing bacteria with unknown auxotrophies in chemically defined media is challenging and often not possible without an extensive trial-and-error approach. In this study, a respiration activity monitoring system for shake flasks and its recent version for microtiter plates were used to clarify unknown auxotrophic deficiencies in the model organism Bacillus pumilus DSM 18097.
Results
Bacillus pumilus DSM 18097 was unable to grow in a mineral medium without the addition of complex compounds. Therefore, a rich chemically defined minimal medium was tested containing basically all vitamins, amino acids and nucleobases, which are essential ingredients of complex components. The strain was successfully cultivated in this medium. By monitoring of the respiration activity, nutrients were supplemented to and omitted from the rich chemically defined medium in a rational way, thus enabling a systematic and fast determination of the auxotrophic deficiencies. Experiments have shown that the investigated strain requires amino acids, especially cysteine or histidine and the vitamin biotin for growth.
Conclusions
The introduced method allows an efficient and rapid identification of unknown auxotrophic deficiencies and can be used to develop a simple chemically defined tailor-made medium. B. pumilus DSM 18097 was chosen as a model organism to demonstrate the method. However, the method is generally suitable for a wide range of microorganisms. By combining a systematic combinatorial approach based on monitoring the respiration activity with cultivation in microtiter plates, high throughput experiments with high information content can be conducted. This approach facilitates media development, strain characterization and cultivation of fastidious microorganisms in chemically defined minimal media while simultaneously reducing the experimental effort.
Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts
(2018)
The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample.
In lab-on-chip systems, electrodes are important for the manipulation (e.g., cell stimulation, electrolysis) within such systems. An alternative to commonly used electrode structures can be a light-addressable electrode. Here, due to the photoelectric effect, the conducting area can be adjusted by modification of the illumination area which enables a flexible control of the electrode. In this work, titanium dioxide based light-addressable electrodes are fabricated by a sol–gel technique and a spin-coating process, to deposit a thin film on a fluorine-doped tin oxide glass. To characterize the fabricated electrodes, the thickness, and morphological structure are measured by a profilometer and a scanning electron microscope. For the electrochemical behavior, the dark current and the photocurrent are determined for various film thicknesses. For the spatial resolution behavior, the dependency of the photocurrent while changing the area of the illuminated area is studied. Furthermore, the addressing of single fluid compartments in a three-chamber system, which is added to the electrode, is demonstrated.
Das anhaltende Wachstum wissenschaftlicher Veröffentlichungen wirft die Fragestellung auf, wie Literaturana-lysen im Rahmen von Forschungsprozessen digitalisiert und somit produktiver realisiert werden können. Insbesondere in informationstechnischen Fachgebieten ist die Forschungspraxis durch ein rasant wachsendes Publikationsaufkommen gekennzeichnet. Infolgedessen bietet sich der Einsatz von Methoden der Textanalyse (Text Analytics) an, die Textdaten automatisch vorbereiten und verarbeiten können. Erkenntnisse entstehen dabei aus Analysen von Wortarten und Subgruppen, Korrelations- sowie Zeitreihenanalysen. Dieser Beitrag stellt die Konzeption und Realisierung eines Prototypen vor, mit dem Anwender bibliographische Daten aus der etablierten Literaturdatenbank EBSCO Discovery Service mithilfe textanalytischer Methoden erschließen können. Der Prototyp basiert auf dem Analysesystem IBM Watson Explorer, das Hochschulen lizenzkostenfrei zur Verfügung steht. Potenzielle Adressaten des Prototypen sind Forschungseinrichtungen, Beratungsunternehmen sowie Entscheidungsträger in Politik und Unternehmenspraxis.
Datenschutz und der 25.5.2018, wie ein Damoklesschwert scheinen beide Begriffe zurzeit im Raum zu stehe. Jeder weiß oder sollte zumindest um das Inkrafttreten der europäischen DSGVO am 25.5.2018 wissen. Viel wurde über wesentliche Neuerungen im Datenschutzrecht berichtet. Nicht zuletzt über gesteigerte organisatorische Anforderungen, Dokumentationspflichten und drohende Bußgelder. Doch was bedeuten diese Neuerungen ganz konkret für die Praxis des Steuerberaters? Anders als man vermuten könnte, werden die datenschutzrechtlichen Neuerungen nicht nur im Bereich der Kanzleiorganisation relevant. Auch im Steuerverwaltungsverfahren sieht sich der Steuerberater datenschutzrechtlichen Fragestellungen gegenüber, bspw. dann, wenn die Finanzbehörden bei der Verarbeitung der personenbezogenen Daten des Mandanten gegen die DSGVO verstoßen. Gleiches gilt in Bereichen des Beschäftigtendatenschutzes. Sowohl der Kanzleiinhaber selbst, als auch seine Arbeitgeber-Mandanten haben die Vorschriften des Beschäftigtendatenschutzes einzuhalten. Der Steuerberater benötigt datenschutzrechtliches Know How, welches unmittelbar seine tägliche Praxis betrifft. Andernfalls besteht das Risiko, dass dieser mit mehr Fragen, als Antworten zurück bleibt.
Physical interaction with small solar system bodies (SSSB) is key for in-situ resource utilization (ISRU). The design of mining missions requires good understanding of SSSB properties, including composition, surface and interior structure, and thermal environment. But as the saying goes "If you've seen one asteroid, you've seen one Asteroid": Although some patterns may begin to appear, a stable and reliable scheme of SSSB classification still has to be evolved. Identified commonalities would enable generic ISRU technology and spacecraft design approaches with a high degree of re-use. Strategic approaches require much broader in-depth characterization of the SSSB populations of interest to the ISRU community. The DLR-ESTEC GOSSAMER Roadmap Science Working Groups identified target-flexible Multiple Near-Earth asteroid (NEA) Rendezvous (MNR) as one of the missions only feasible with solar sail propulsion, showed the ability to access any inclination and a wide range of heliocentric distances as well as continuous operation close to Earth's orbit where low delta-v objects reside.
The efficiency concepts of Bahadur and Pitman are used to compare the Wilcoxon tests in paired and independent survey samples. A comparison through the length of corresponding confidence intervals is also done. Simple conditions characterizing the dominance of a procedure are derived. Statistical tests for checking these conditions are suggested and discussed.
During rapid deceleration of the body, tendons buffer part of the elongation of the muscle-tendon unit (MTU), enabling safe energy dissipation via eccentric muscle contraction. Yet, the influence of changes in tendon stiffness within the physiological range upon these lengthening contractions is unknown. This study aimed to examine the effect of training-induced stiffening of the Achilles tendon on triceps surae muscle-tendon behavior during a landing task. Twenty-one male subjects were assigned to either a 10-week resistance-training program consisting of single-leg isometric plantarflexion (n = 11) or to a non-training control group (n = 10). Before and after the training period, plantarflexion force, peak Achilles tendon strain and stiffness were measured during isometric contractions, using a combination of dynamometry, ultrasound and kinematics data. Additionally, testing included a step-landing task, during which joint mechanics and lengths of gastrocnemius and soleus fascicles, Achilles tendon, and MTU were determined using synchronized ultrasound, kinematics and kinetics data collection. After training, plantarflexion strength and Achilles tendon stiffness increased (15 and 18%, respectively), and tendon strain during landing remained similar. Likewise, lengthening and negative work produced by the gastrocnemius MTU did not change detectably. However, in the training group, gastrocnemius fascicle length was offset (8%) to a longer length at touch down and, surprisingly, fascicle lengthening and velocity were reduced by 27 and 21%, respectively. These changes were not observed for soleus fascicles when accounting for variation in task execution between tests. These results indicate that a training-induced increase in tendon stiffness does not noticeably affect the buffering action of the tendon when the MTU is rapidly stretched. Reductions in gastrocnemius fascicle lengthening and lengthening velocity during landing occurred independently from tendon strain. Future studies are required to provide insight into the mechanisms underpinning these observations and their influence on energy dissipation.
We propose a stochastic programming method to analyse limit and shakedown of structures under random strength with lognormal distribution. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit or the shakedown limit. The edge-based smoothed finite element method (ES-FEM) using three-node linear triangular elements is used.
Dimensionen 2-2018: Magazin der FH Aachen University of Applied Sciences - Virtuelle Realitäten
(2018)
Virtuelle Realitäten
Inhaltsverzeichnis
6 Erweiterte Dimensionen: Special zum Thema Virtual Reality
10 "VR und AR werden unsere Welt durchdringen": Ein Interview zum Potenzial von Virtual und Augmented Reality
14 Lernen aus einem anderen Blickwinkel: VR wird in Studium und Lehre zunehmend angewandt
18 Parallele Realitäten in der Forschung: Virtual und Augmented Reality in Forschungsprojekten
22 Willkommen in der Welt der Möglichkeiten: Wie real ist die Illusion der Realität
24 Eine zündende Idee: Institut für Mikrowellen- und Plasmatechnik (IMP) entwickelt neue Plasmazündkerze für sparsamere Benzinmotoren
28 Der Elefant im Park: "WESTPARK story constructed": Studierende bauen skulpturales Möbel
30 Herr Bernoulli geht auf Reisen: Das "aero | race lab" bringt Experimente zur Luft- und Raumfahrt an die Schulen
32 Eine Auszeit vom Alltag: Martin Stockberg schafft Kunstwerke im Sand
36 Der Einer im urbanen Mobilitätstetris: An der FH Aachen wird urbane Elektromobilität neu gedacht
39 Der Primzahlwürfel: Kopfnuss
40 Schwarz Weiß Bunt: Die politische Kunst des FH-Absolventen Ralf Metzenmacher
44 Die Champions League des Schweißens: LaVa-X will das Laserstrahlschweißen im Vakuum etablieren
46 Auf der Suche nach dem goldenen Schnatz: Stöcke statt Besen. Spielfeld statt Arena. In Jülich spielen Studierende Quidditch.
48 Bei ihm wird Science-Fiction zu Science-Fact: Volker Schmid erzählt von seiner Arbeit beim Deutschen Zentrum für Luft- und Raumfahrt (DLR)
52 Die Ideenschmieden: Junge Menschen aus aller Welt diskutieren bei den Summerschools über Zukunftsthemen
56 Forschung auf höchstem Niveau: Dr. Jan Oberländer und Doktorand Dua Özsoylu stehen für das, was das Institut für Nano- und Biotechnologien auszeichnet
58 Der Dom und ich: Dompublikation und LEGO-Throne zum Jubiläum 40 Jahre UNESCO-Weltkulturerbe
62 Sag "Ja" zum Studium: Der neue kooperative Bachelorstudiengang "Elektrotechnik mit Orientierungssemester"
63 Impressum
Grenzgänge: Op jöck in Vaals mit Peter Sparla
Inhaltsverzeichnis
6 "Mr. Vaals": Ein Spaziergang mit Peter Sparla durch die niederländische Gemeinde
14 Ein Verein hebt ab: Von der Theorie in die Praxis: Die Flugtechnische Arbeitsgemeinschaft will Studierende fürs Fliegen begeistern
18 Vom Flugplatzkind zur Ingenieurin: Sarah Hamacher hat Luft- und Raumfahrt studiert und arbeitet jetzt bei der ADAC-Luftfahrttechnik
20 Mit Sonne im Tank durch das australische Outback: FH-Student Enno Dülberg berichtet von der World Solar Challenge
24 Es steckt mehr dahinter: Eine Eschweiler Firma entwickelt Elektronik-Lösungen für Anhängerkupplungen - mit Unterstützung der FH Aachen
27 Von Meknès nach Jülich: Die Geschichte von Rabab Azizi
28 Das blaue Wunder neu erleben: Aachener Tuchtradition soll wieder in Mode kommen
32 Es werde Licht: Markus van Hauten macht spektakuläre Landschaftsfotos
36 Maschinenbau von morgen: Dr. Julia Kessler forscht zu additiv gefertigten Leichtbaustrukturen
39 Vier Siebenen und eine Eins: Kopfnuss
40 Auf Tuchfühlung mit der Praxis: Das ausbildungsintegrierende Studium ist anspruchsvoll und fordernd. Aber es bietet den Studierenden und Unternehmen auch viel.
44 Eine große Bühne für die Forschung: FH aachen präsentiert das Spektrum ihrer wissenschaftlichen Arbeit
46 Eine Erfolgsstory: Das Institut für Nano- und Biotechnologien feiert sein 10-jähriges Jubiläum
49 Das Ingenieurstudium früher und heute: Der Verein "Ingenieurfreunde der FH Aachen" blickt auf eine ereignisreiche Zeit zurück
50 Ist es ein Flugzeug? Ist es ein Multikopter: Nein es ist PhoenAix! Das Fluggerät soll Vorteile von Flugzeug- und Hubschraubertechnik kombinieren
54 Güterwagen der Zukunft: Im Studiengang Schienfahrzeugtechnik wird an intelligenten und hoch technisierten Güterwaggons gearbeitet
58 Wenn Gedanken Gestalt annehmen: Prof. Thomas Tünnemann zum Projekt Neo Forma
60 Vorhang auf für die Wissenschaft: Future-Lab-Gala im Theater Aachen
62 Impressum