@article{GoettenFingerHavermannetal.2021, author = {G{\"o}tten, Falk and Finger, Felix and Havermann, Marc and Braun, Carsten and Marino, M. and Bil, C.}, title = {Full configuration drag estimation of short-to-medium range fixed-wing UAVs and its impact on initial sizing optimization}, series = {CEAS Aeronautical Journal}, volume = {12}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Berlin}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-021-00522-w}, pages = {589 -- 603}, year = {2021}, abstract = {The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used for surveillance, reconnaissance, and search and rescue missions. The aircraft is simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft.}, language = {en} } @inproceedings{GoettscheKornAmato2015, author = {G{\"o}ttsche, Joachim and Korn, Michael and Amato, Alexandre}, title = {The Passivhaus concept for the Arabian Peninsula - An energetic-economical evaluation considering the thermal comfort}, series = {QScience Proceedings: Vol 2015}, booktitle = {QScience Proceedings: Vol 2015}, doi = {10.5339/qproc.2015.qgbc.38}, pages = {8 Seiten}, year = {2015}, abstract = {The Passivhaus building standard is a concept developed for the realization of energy-efficient and economical buildings with a simultaneous high utilization comfort under European climate conditions. Major elements of the Passivhaus concept are a high thermal insulation of the external walls, the use of heat and/or solar shading glazing as well as an airtight building envelope in combination with energy-efficient technical building installations and heating or cooling generators, such as an efficient energy-recovery in the building air-conditioning. The objective of this research project is the inquiry to determine the parameters or constraints under which the Passivhaus concept can be implemented under the arid climate conditions in the Arabian Peninsula to achieve an energy-efficient and economical building with high utilization comfort. In cooperation between the Qatar Green Building Council (QGBC), Barwa Real Estate (BRE) and Kahramaa the first Passivhaus was constructed in Qatar and on the Arabian Peninsula in 2013. The Solar-Institut J{\"u}lich of Aachen University of Applied Science supports the Qatar Green Building Council with a dynamic building and equipment simulation of the Passivhaus and the neighbouring reference building. This includes simulation studies with different component configurations for the building envelope and different control strategies for heating or cooling systems as well as the air conditioning of buildings to find an energetic-economical optimum. Part of these analyses is the evaluation of the energy efficiency of the used energy recovery system in the Passivhaus air-conditioning and identification of possible energy-saving effects by the use of a bypass function integrated in the heat exchanger. In this way it is expected that on an annual basis the complete electricity demand of the building can be covered by the roof-integrated PV generator.}, language = {en} } @inproceedings{GoettscheRoether2014, author = {G{\"o}ttsche, Joachim and R{\"o}ther, Sascha}, title = {Science College Overbach - Innovatives Bildungszentrum in J{\"u}lich-Barmen}, series = {18. Internationale Passivhaustagung, Aachen, April 2014}, booktitle = {18. Internationale Passivhaustagung, Aachen, April 2014}, pages = {6 Seiten}, year = {2014}, abstract = {Preprint der Autoren}, language = {de} } @masterthesis{Goetz2023, type = {Bachelor Thesis}, author = {G{\"o}tz, Daniela}, title = {Entwicklung eines Erscheinungsbildes f{\"u}r das Start-up-Unternehmen CoArea}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {93 Seiten}, year = {2023}, abstract = {Diese Bachelorarbeit befasst sich mit dem Corporate Design des aufstrebenden Startups "CoArea". Seine innovative Plattform vermittelt ungenutzte Fl{\"a}chen im urbanen Raum und bringt Fl{\"a}chenbedarf und -bereitstellung intelligent zusammen. Die Arbeit untersucht, wie das Erscheinungsbild von CoArea das Unternehmen als modern, nachhaltig und ressourcenschonend positioniert. Durch das neu gestaltete Corporate Design wird diese besondere Herangehensweise zur effizienten Nutzung begrenzter Ressourcen unserer Umwelt durch CoArea deutlich und nach außen getragen. CoArea strebt danach, die positive Entwicklung der St{\"a}dte voranzutreiben und die soziale Nachhaltigkeit durch den Austausch und die Interaktion zwischen verschiedenen Menschen und Gemeinschaften zu f{\"o}rdern.}, language = {de} } @article{HaegerJolmesOyenetal.2024, author = {Haeger, Gerrit and Jolmes, Tristan and Oyen, Sven and Jaeger, Karl-Erich and Bongaerts, Johannes and Sch{\"o}rken, Ulrich and Siegert, Petra}, title = {Novel recombinant aminoacylase from Paraburkholderia monticola capable of N-acyl-amino acid synthesis}, series = {Applied Microbiology and Biotechnology}, journal = {Applied Microbiology and Biotechnology}, number = {108}, publisher = {Springer}, address = {Berlin}, issn = {1432-0614}, doi = {10.1007/s00253-023-12868-8}, pages = {14 Seiten}, year = {2024}, abstract = {N-Acyl-amino acids can act as mild biobased surfactants, which are used, e.g., in baby shampoos. However, their chemical synthesis needs acyl chlorides and does not meet sustainability criteria. Thus, the identification of biocatalysts to develop greener synthesis routes is desirable. We describe a novel aminoacylase from Paraburkholderia monticola DSM 100849 (PmAcy) which was identified, cloned, and evaluated for its N-acyl-amino acid synthesis potential. Soluble protein was obtained by expression in lactose autoinduction medium and co-expression of molecular chaperones GroEL/S. Strep-tag affinity purification enriched the enzyme 16-fold and yielded 15 mg pure enzyme from 100 mL of culture. Biochemical characterization revealed that PmAcy possesses beneficial traits for industrial application like high temperature and pH-stability. A heat activation of PmAcy was observed upon incubation at temperatures up to 80 °C. Hydrolytic activity of PmAcy was detected with several N-acyl-amino acids as substrates and exhibited the highest conversion rate of 773 U/mg with N-lauroyl-L-alanine at 75 °C. The enzyme preferred long-chain acyl-amino-acids and displayed hardly any activity with acetyl-amino acids. PmAcy was also capable of N-acyl-amino acid synthesis with good conversion rates. The best synthesis results were obtained with the cationic L-amino acids L-arginine and L-lysine as well as with L-leucine and L-phenylalanine. Exemplarily, L-phenylalanine was acylated with fatty acids of chain lengths from C8 to C18 with conversion rates of up to 75\%. N-lauroyl-L-phenylalanine was purified by precipitation, and the structure of the reaction product was verified by LC-MS and NMR.}, language = {en} } @article{HaegerProbstJaegeretal.2023, author = {Haeger, Gerrit and Probst, Johanna and Jaeger, Karl-Erich and Bongaerts, Johannes and Siegert, Petra}, title = {Novel aminoacylases from Streptomyces griseus DSM 40236 and their recombinant production in Streptomyces lividans}, series = {FEBS Open Bio}, volume = {13}, journal = {FEBS Open Bio}, number = {12}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {2211-5463}, doi = {10.1002/2211-5463.13723}, pages = {2224 -- 2238}, year = {2023}, abstract = {Amino acid-based surfactants are valuable compounds for cosmetic formulations. The chemical synthesis of acyl-amino acids is conventionally performed by the Schotten-Baumann reaction using fatty acyl chlorides, but aminoacylases have also been investigated for use in biocatalytic synthesis with free fatty acids. Aminoacylases and their properties are diverse; they belong to different peptidase families and show differences in substrate specificity and biocatalytic potential. Bacterial aminoacylases capable of synthesis have been isolated from Burkholderia, Mycolicibacterium, and Streptomyces. Although several proteases and peptidases from S. griseus have been described, no aminoacylases from this species have been identified yet. In this study, we investigated two novel enzymes produced by S. griseus DSM 40236ᵀ . We identified and cloned the respective genes and recombinantly expressed an α-aminoacylase (EC 3.5.1.14), designated SgAA, and an ε-lysine acylase (EC 3.5.1.17), designated SgELA, in S. lividans TK23. The purified aminoacylase SgAA was biochemically characterized, focusing on its hydrolytic activity to determine temperature- and pH optima and stabilities. The aminoacylase could hydrolyze various acetyl-amino acids at the Nα -position with a broad specificity regarding the sidechain. Substrates with longer acyl chains, like lauroyl-amino acids, were hydrolyzed to a lesser extent. Purified aminoacylase SgELA specific for the hydrolysis of Nε -acetyl-L-lysine was unstable and lost its enzymatic activity upon storage for a longer period but could initially be characterized. The pH optimum of SgELA was pH 8.0. While synthesis of acyl-amino acids was not observed with SgELA, SgAA catalyzed the synthesis of lauroyl-methionine.}, language = {en} } @article{HaegerWirgesTanzmannetal.2023, author = {Haeger, Gerrit and Wirges, Jessika and Tanzmann, Nicole and Oyen, Sven and Jolmes, Tristan and Jaeger, Karl-Erich and Sch{\"o}rken, Ulrich and Bongaerts, Johannes and Siegert, Petra}, title = {Chaperone assisted recombinant expression of a mycobacterial aminoacylase in Vibrio natriegens and Escherichia coli capable of N-lauroyl-L-amino acid synthesis}, series = {Microbial Cell Factories}, journal = {Microbial Cell Factories}, number = {22}, publisher = {Springer Nature}, issn = {1475-2859}, doi = {10.1186/s12934-023-02079-1}, pages = {Article number: 77 (2023)}, year = {2023}, abstract = {Background Aminoacylases are highly promising enzymes for the green synthesis of acyl-amino acids, potentially replacing the environmentally harmful Schotten-Baumann reaction. Long-chain acyl-amino acids can serve as strong surfactants and emulsifiers, with application in cosmetic industries. Heterologous expression of these enzymes, however, is often hampered, limiting their use in industrial processes. Results We identified a novel mycobacterial aminoacylase gene from Mycolicibacterium smegmatis MKD 8, cloned and expressed it in Escherichia coli and Vibrio natriegens using the T7 overexpression system. The recombinant enzyme was prone to aggregate as inclusion bodies, and while V. natriegens Vmax™ could produce soluble aminoacylase upon induction with isopropyl β-d-1-thiogalactopyranoside (IPTG), E. coli BL21 (DE3) needed autoinduction with lactose to produce soluble recombinant protein. We successfully conducted a chaperone co-expression study in both organisms to further enhance aminoacylase production and found that overexpression of chaperones GroEL/S enhanced aminoacylase activity in the cell-free extract 1.8-fold in V. natriegens and E. coli. Eventually, E. coli ArcticExpress™ (DE3), which co-expresses cold-adapted chaperonins Cpn60/10 from Oleispira antarctica, cultivated at 12 °C, rendered the most suitable expression system for this aminoacylase and exhibited twice the aminoacylase activity in the cell-free extract compared to E. coli BL21 (DE3) with GroEL/S co-expression at 20 °C. The purified aminoacylase was characterized based on hydrolytic activities, being most stable and active at pH 7.0, with a maximum activity at 70 °C, and stability at 40 °C and pH 7.0 for 5 days. The aminoacylase strongly prefers short-chain acyl-amino acids with smaller, hydrophobic amino acid residues. Several long-chain amino acids were fairly accepted in hydrolysis as well, especially N-lauroyl-L-methionine. To initially evaluate the relevance of this aminoacylase for the synthesis of N-acyl-amino acids, we demonstrated that lauroyl-methionine can be synthesized from lauric acid and methionine in an aqueous system. Conclusion Our results suggest that the recombinant enzyme is well suited for synthesis reactions and will thus be further investigated.}, language = {en} } @techreport{HagemannCardinalGartzenetal.1998, author = {Hagemann, Hans-J{\"u}rgen and Cardinal, Peter and Gartzen, Johannes and K{\"o}hler, Bernd and Petschke, U. and Reißmann, G{\"u}nter}, title = {Laser-Mikrostrukturierung von BaTiO3 Gr{\"u}nfolien und Keramiken : Abschlußbericht ; gef{\"o}rdert mit Mitteln aud dem Programm "Anwendungsorientierte Forschung und Entwicklung an Fachhochschulen" des Bundesministeriums f{\"u}r Bildung, Wissenschaft, Forschung}, year = {1998}, abstract = {An BaTiO3 Keramik als Modellsubstanz und mit Nd:YAG- und Excimer-Lasern wurde die Mikrostrukturierung von Gr{\"u}nk{\"o}rperpreßlingen, deren Schrumpfungsverhalten beim Sintern und die Mikrostrukturierung von gesinterten Keramiken untersucht. F{\"u}r die bessere Vergleichbarkeit wurden alle keramischen Folien, Preßlinge und Sinterwerkstoffe im Rahmen des Projektes hergestellt. Die Nd:YAG Laserbearbeitung erfolgte mit einem Rasterverfahren, bei dem der fokussierte Strahl mit Hilfe eines Scanners und eines Umlenkspiegels entlang der Bearbeitungskontur gef{\"u}hrt wurde. Bei der Excimer Laserbearbeitung wurden die Strukturen ohne Relativbewegung zwischen Strahlquelle und Bearbeitungsobjekt durch die Abbildung einer Maske erzeugt. Mit dem Nd:YAG Laser (Wellenl{\"a}nge 1,06 µ m) war eine abtragende Bearbeitung nur bei den Gr{\"u}nk{\"o}rpern, nicht aber bei den gesinterten Keramiken m{\"o}glich. Mit dem Excimer Laser (Wellenl{\"a}nge 248 nm) konnten dagegen sowohl Gr{\"u}nk{\"o}rper als auch gesinterte Keramiken strukturiert werden. Wenn die Genauigkeitsanforderungen nicht unter ± 10 µm liegen, die Bearbeitungskonturen m{\"o}glichst geradlinig sind und der Anteil der zu bearbeitenden Fl{\"a}che klein ist, kann mit Nd:YAG-Lasern eine effiziente Mikrostukturierung von keramischen Gr{\"u}nk{\"o}rpern durchgef{\"u}hrt werden. Strukturierte Gr{\"u}nk{\"o}rper k{\"o}nnen reproduzierbar und unverzerrt zu keramischen Bauteilen gesintert werden. Mit Excimer-Lasern wird eine h{\"o}here Genauigkeit und Qualit{\"a}t bei der Bearbeitung von Gr{\"u}nk{\"o}rpern und Keramiken erreicht. Die Bearbeitungseffizienz l{\"a}sst sich durch eine hohe Pulswiederholfrequenz und durch die simultane Bearbeitung großer Fl{\"a}chen steigern. Das f{\"u}r Excimer-Laserstrahlung zweckm{\"a}ßige Abbildungsverfahren hat besondere Vorteile, wenn ein fl{\"a}chiger Abtrag mit komplexen Strukturen verwirklicht werden soll, wobei Toleranzen und Reproduzierbarkeiten von besser als ± 5 µm realisiert werden konnten. Die Mikrostrukturierung mit Excimer-Lasern ist an Gr{\"u}nk{\"o}rpern und an gebrannten Keramiken gleichermaßen m{\"o}glich. Die Abtragsraten liegen bei Gr{\"u}nk{\"o}rpern mit 0,2 µm pro Puls zwar um ca. 50\% h{\"o}her als bei Keramiken, es ist jedoch zweifelhaft, ob dieser Vorteil den gr{\"o}ßeren prozeßtechnischen Aufwand bei der Bearbeitung von Gr{\"u}nk{\"o}rpern rechtfertigen kann.}, subject = {Keramischer Werkstoff}, language = {de} } @techreport{HagemannHegerHemmeetal.2004, author = {Hagemann, Hans-J{\"u}rgen and Heger, Michael and Hemme, Heinrich and Samm, Doris and Schmitz, G{\"u}nter}, title = {Entwicklung und Evaluation interaktiver, multimedialer Lernsoftware f{\"u}r technische und physikalische Praktika in Ingenieurstudieng{\"a}ngen: INGMEDIA ; Projektlaufzeit: 01. Apr. 2001 - 31. Dez. 2003 / FH Aachen. Projektleiter: Hans-J{\"u}rgen Hagemann}, year = {2004}, abstract = {Im Projekt INGMEDIA ist die Lernform "Praktikum" zu einer selbst bestimmten Lernumgebung weiterentwickelt worden. Vielf{\"a}ltige Kontextangebote bieten individuelle Lerneinstiegsm{\"o}glichkeiten und aktivieren selbstgesteuertes Lernen. Praktika aus drei Bereichen des Ingenieurstudiums, "physikalische Grundlagenpraktika", "Telematiklabore f{\"u}r Elektronik" in der Studienmitte und "virtuelle Technologiepraktika" f{\"u}r Fortgeschrittene , wurden mit Hilfe der Neuen Medien umgestaltet, erprobt und evaluiert. Alle Lern- und Praktikumseinheiten k{\"o}nnen mit Standard-Internet-Browsern {\"u}ber die INGMEDIA-Lernumgebung (ILIAS Open source) benutzt werden. F{\"u}r Lehrende wird die Plattform durch ein komfortables Offline-Autorensystem erg{\"a}nzt, mit dem mulitmediale Lern- und Praktikumseinheiten ohne spezielle Programmierkenntnisse erstellt und automatisch in die Datenbank der ILIAS Lernplattform importiert werden k{\"o}nnen. Die weiterentwickelten Praktikumseinheiten werden seit dem Wintersemester 2002/03 im regul{\"a}ren Lehrbetrieb eingesetzt und formativ evaluiert. Bei den Erprobungen der hypermedialen Lerneinheiten in physikalischen Grundpraktika sch{\"a}tzen die Lernenden den Stand ihrer Vorbereitung als befriedigend ein, die Praktikumsbetreuer konstatierten eine merkliche Verbesserung des Wissensstandes. Die Mehrheit der Studierenden begr{\"u}ßte vor allem die durch die Telematik angebotene gr{\"o}ßere Freiheit eines zeit- und ortsunabh{\"a}ngigen Lernens und der eigenen Lernorganisation. Das virtuelle Technologie-Praktikum: "Sensor-Fertigung" erm{\"o}glicht die Neukonzeption einer industrienahen Ausbildung von Ingenieuren in innovativen Technologien und hat sich bereits bestens bew{\"a}hrt. Die empirischen Befunde {\"u}ber alle im INGMEDIA-Projekt evaluierten Praktika weisen darauf hin, dass Akzeptanz und Lernerfolg beim Einsatz neuer Medien umso deutlicher sichtbar werden je gr{\"o}ßer die Selbstlern- und Medienkompetenzen der Studierenden sind.}, subject = {Hochschuldidaktik}, language = {de} } @article{HagenkampBlankeDoering2021, author = {Hagenkamp, Markus and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Thermoelectric building temperature control: a potential assessment}, series = {International Journal of Energy and Environmental Engineering}, volume = {13}, journal = {International Journal of Energy and Environmental Engineering}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s40095-021-00424-x}, pages = {241 -- 254}, year = {2021}, abstract = {This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 ∘C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand Q˙h=100W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants.}, language = {en} }