@article{HafidiElHatkaSchmitzetal.2024, author = {Hafidi, Youssef and El Hatka, Hicham and Schmitz, Dominik and Krauss, Manuel and Pettrak, J{\"u}rgen and Biel, Markus and Ittobane, Najim}, title = {Sustainable soil additives for water and micronutrient supply: swelling and chelating properties of polyaspartic acid hydrogels utilizing newly developed crosslinkers}, series = {Gels}, volume = {10}, journal = {Gels}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2310-2861}, doi = {10.3390/gels10030170}, pages = {Artikel 170}, year = {2024}, abstract = {Drought and water shortage are serious problems in many arid and semi-arid regions. This problem is getting worse and even continues in temperate climatic regions due to climate change. To address this problem, the use of biodegradable hydrogels is increasingly important for the application as water-retaining additives in soil. Furthermore, efficient (micro-)nutrient supply can be provided by the use of tailored hydrogels. Biodegradable polyaspartic acid (PASP) hydrogels with different available (1,6-hexamethylene diamine (HMD) and L-lysine (LYS)) and newly developed crosslinkers based on diesters of glycine (GLY) and (di-)ethylene glycol (DEG and EG, respectively) were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) and regarding their swelling properties (kinetic, absorbency under load (AUL)) as well as biodegradability of PASP hydrogel. Copper (II) and zinc (II), respectively, were loaded as micronutrients in two different approaches: in situ with crosslinking and subsequent loading of prepared hydrogels. The results showed successful syntheses of di-glycine-ester-based crosslinkers. Hydrogels with good water-absorbing properties were formed. Moreover, the developed crosslinking agents in combination with the specific reaction conditions resulted in higher water absorbency with increased crosslinker content used in synthesis (10\% vs. 20\%). The prepared hydrogels are candidates for water-storing soil additives due to the biodegradability of PASP, which is shown in an exemple. The incorporation of Cu(II) and Zn(II) ions can provide these micronutrients for plant growth.}, language = {en} } @incollection{Fissabre2024, author = {Fissabre, Anke}, title = {Eine moderne Sainte-Chapelle in K{\"o}ln. Otto Bartnings Stahlkirche auf der Pressa 1928}, series = {Baugedanken: Einsichten, Ansichten, Aussichten f{\"u}r Jan Pieper zum 80. Geburtstag}, booktitle = {Baugedanken: Einsichten, Ansichten, Aussichten f{\"u}r Jan Pieper zum 80. Geburtstag}, editor = {Naujokat, Anke and Hake, Verena and Schindler, Bruno and Sch{\"o}tten, Bj{\"o}rn}, publisher = {Geym{\"u}ller Verag f{\"u}r Architektur}, address = {Aachen}, isbn = {978-3-943164-87-9}, pages = {66 -- 81}, year = {2024}, language = {de} } @inproceedings{RuettersBragardDolls2024, author = {R{\"u}tters, Ren{\´e} and Bragard, Michael and Dolls, Sarah}, title = {The Inverted Rotary Pendulum: Facilitating Practical Teaching in Advanced Control Engineering}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578937}, pages = {5 Seiten}, year = {2024}, abstract = {This paper outlines a practical approach to teach control engineering principles, with an inverted rotary pendulum, serving as an illustrative example. It shows how the pendulum is embedded in an advanced course of control engineering. This approach is incorporated into a flipped-classroom concept, as well as classical teaching concepts, offering students practical experience in control engineering. In addition, the design of the pendulum is shown, using a Raspberry Pi as the target platform for Matlab Simulink. This pendulum can be used in the classroom to evaluate the controller design mentioned above. It is analysed if the use of the pendulum generates a deeper understanding of the learning contents.}, language = {en} } @inproceedings{BeckerBragard2024, author = {Becker, Tim and Bragard, Michael}, title = {Low-Voltage DC Training Lab for Electric Drives - Optimizing the Balancing Act Between High Student Throughput and Individual Learning Speed}, series = {2024 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2024 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, issn = {2165-9559}, doi = {10.1109/EDUCON60312.2024.10578902}, pages = {8 Seiten}, year = {2024}, abstract = {After a brief introduction of conventional laboratory structures, this work focuses on an innovative and universal approach for a setup of a training laboratory for electric machines and drive systems. The novel approach employs a central 48 V DC bus, which forms the backbone of the structure. Several sets of DC machine, asynchronous machine and synchronous machine are connected to this bus. The advantages of the novel system structure are manifold, both from a didactic and a technical point of view: Student groups can work on their own performance level in a highly parallelized and at the same time individualized way. Additional training setups (similar or different) can easily be added. Only the total power dissipation has to be provided, i.e. the DC bus balances the power flow between the student groups. Comparative results of course evaluations of several cohorts of students are shown.}, language = {en} } @article{Golland2024, author = {Golland, Alexander}, title = {Datenschutz beim Einsatz k{\"u}nstlicher Intelligenz im Unternehmen}, series = {NWB}, journal = {NWB}, number = {6}, publisher = {NWB}, address = {Herne}, issn = {0028-3460}, pages = {425 -- 432}, year = {2024}, abstract = {Seit Ende 2022 pr{\"a}gt das Schlagwort „K{\"u}nstliche Intelligenz" (KI) nicht nur den rechtswissenschaftlichen Diskurs. Die allgemeine Verf{\"u}gbarkeit von generativen KI-Modellen, allen voran die großen Sprachmodelle (Large Language Models, kurz: LLM) wie ChatGPT von OpenAI oder Bing AI von Microsoft, erfreuen sich gr{\"o}ßter Beliebtheit: LLM sind in der Lage, auf Grundlage statistischer Methoden - eine entsprechende Schnittstelle (Interface) vorausgesetzt - auch technisch wenig versierten Nutzern verst{\"a}ndliche Antworten auf ihre Fragen zu liefern. Dabei werden nicht nur umfassend Nutzerdaten verarbeitet, sondern auch auf weitere personenbezogene Daten zugegriffen sowie neue Daten erzeugt. Der Beitrag geht der Frage nach, welche spezifischen datenschutzrechtlichen Herausforderungen sich f{\"u}r Unternehmen beim Einsatz solcher LLM stellen.}, language = {de} } @article{EngelmannSimsekShalabyetal.2024, author = {Engelmann, Ulrich M. and Simsek, Beril and Shalaby, Ahmed and Krause, Hans-Joachim}, title = {Key contributors to signal generation in frequency mixing magnetic detection (FMMD): an in silico study}, series = {Sensors}, volume = {24}, journal = {Sensors}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s24061945}, pages = {Artikel 1945}, year = {2024}, abstract = {Frequency mixing magnetic detection (FMMD) is a sensitive and selective technique to detect magnetic nanoparticles (MNPs) serving as probes for binding biological targets. Its principle relies on the nonlinear magnetic relaxation dynamics of a particle ensemble interacting with a dual frequency external magnetic field. In order to increase its sensitivity, lower its limit of detection and overall improve its applicability in biosensing, matching combinations of external field parameters and internal particle properties are being sought to advance FMMD. In this study, we systematically probe the aforementioned interaction with coupled N{\´e}el-Brownian dynamic relaxation simulations to examine how key MNP properties as well as applied field parameters affect the frequency mixing signal generation. It is found that the core size of MNPs dominates their nonlinear magnetic response, with the strongest contributions from the largest particles. The drive field amplitude dominates the shape of the field-dependent response, whereas effective anisotropy and hydrodynamic size of the particles only weakly influence the signal generation in FMMD. For tailoring the MNP properties and parameters of the setup towards optimal FMMD signal generation, our findings suggest choosing large particles of core sizes dc > 25 nm nm with narrow size distributions (σ < 0.1) to minimize the required drive field amplitude. This allows potential improvements of FMMD as a stand-alone application, as well as advances in magnetic particle imaging, hyperthermia and magnetic immunoassays.}, language = {en} } @masterthesis{Albrecht2024, type = {Bachelor Thesis}, author = {Albrecht, Dustin}, title = {„ARRK Journeys" Filmformat-Konzept}, publisher = {FH Aachen}, address = {Aachen}, pages = {26 Seiten}, year = {2024}, abstract = {Das Projekt "ARRK Journeys" entwickelt ein neues Dokumentarfilm-Format, das darauf abzielt, potenzielle Mitarbeiter f{\"u}r die ARRK Engineering GmbH zu gewinnen Das Ziel des Projekts ist es, die Vielfalt an Karrierem{\"o}glichkeiten bei der ARRK Engineering GmbH aufzuzeigen und die Attraktivit{\"a}t des Unternehmens als Arbeitgeber zu betonen. Durch individuelle Mitarbeitergeschichten werden die Fragen beantwortet, warum eine berufliche Laufbahn bei ARRK erstrebenswert ist, ob jeder die M{\"o}glichkeit hat, bei ARRK zu arbeiten, und welche Entwicklungsm{\"o}glichkeiten das Unternehmen bietet. "ARRK Journeys" betont das Wohlbefinden der Mitarbeiter und ihre pers{\"o}nliche Bindung zum Unternehmen, um eine positive Arbeitgebermarke zu schaffen. "ARRK Journeys" pr{\"a}sentiert die ARRK Engineering GmbH als attraktiven Arbeitgeber und inspiriert potenzielle Mitarbeiter dazu, ihren eigenen Weg zu finden.}, language = {de} } @masterthesis{Berwanger2024, type = {Bachelor Thesis}, author = {Berwanger, Natalie}, title = {Social Media Kampagne - Produktwerbung : Videobegleitende Social Media Kampagne zur Vermarktung eines Produkts}, publisher = {FH Aachen}, address = {Aachen}, pages = {37 Seiten}, year = {2024}, abstract = {Diese zweiw{\"o}chige Social Media Kampagne pr{\"a}sentiert ein Auto durch eine Fusion von realer und digitaler Kunst, unterst{\"u}tzt von audiovisuellen Elementen. Ziel ist es, ein neues Erlebnis zu schaffen, das nachhaltige Mobilit{\"a}t in st{\"a}dtischer Kultur reflektiert und fortschrittliche Technologien nutzt.}, language = {de} } @masterthesis{Dankelmann2024, type = {Bachelor Thesis}, author = {Dankelmann, Florian}, title = {Almanya : kulinarische Br{\"u}cken und Soziale Bindungen der t{\"u}rkischen Diaspora in Deutschland}, publisher = {FH Aachen}, address = {Aachen}, pages = {93 Seiten}, year = {2024}, abstract = {Die fotografische Arbeit "Almanya" veranschaulicht Teilaspekte der t{\"u}rkischen Kultur anhand von Repr{\"a}sentantinnen und Repr{\"a}sentanten der t{\"u}rkeist{\"a}mmigen Community in Deutschland. Mit einem Fokus auf Kulinarik und Formen des Zusammenlebens werden Menschen mit t{\"u}rkischen Wurzeln portr{\"a}tiert, sodass am Ende ein Einblick in deren Lebens- und Gedankenwelt erm{\"o}glicht wird und kulinarische Br{\"u}cken zwischen Deutschen und der t{\"u}rkischen Kultur gebaut werden. Die enthaltene Botschaft, welche das Projekt den Rezipient:innen {\"u}berbringt, ist in einem multikulturellen Land wie Deutschland von großer Wichtigkeit f{\"u}r gegenseitiges Verst{\"a}ndnis und bildet den Boden f{\"u}r ein harmonisches Miteinander.}, language = {de} } @masterthesis{Bunar2024, type = {Bachelor Thesis}, author = {Bunar, Moritz}, title = {Land Rover Symbiosis : Seegras erforschen und erleben}, publisher = {FH Aachen}, address = {Aachen}, pages = {149 Seiten}, year = {2024}, abstract = {Seegras wird als „Rohstoff der Zukunft" betitelt, da es helfen k{\"o}nnte, eine Reihe von globalen Problemen zu bek{\"a}mpfen. Viele der erhofften Innovationen sind heute aber noch hypothetisch. Außerdem ist das Thema in der westlichen Welt trotz der Neigung zum Klimaschutz kaum bekannt. Die Idee von „Land Rover Symbiosis" ist ein nachhaltiges Tourismuskonzept, das Forschung und Erlebnisreisen miteinander verkn{\"u}pft. Auf einer 70m Katamaran Superyacht ist Platz f{\"u}r Forschungszwecke auf der einen und Raum f{\"u}r Expeditionsurlaub auf der anderen Seite. So entsteht ein Verh{\"a}ltnis an Bord, bei dem beide Parteien voneinander profitieren: Wissenschaftler:innen erhalten finanzielle Unterst{\"u}tzung und Kund:innen haben ein klimaneutrales Urlaubserlebnis, bei dem sie hautnah die Vorz{\"u}ge und Potenziale von Seegras kennenlernen.}, language = {de} } @masterthesis{Brauweiler2024, type = {Bachelor Thesis}, author = {Brauweiler, Philipp}, title = {incontrare : Gestaltung eines Meeting Raumes durch Konzeptm{\"o}bel}, publisher = {FH Aachen}, address = {Aachen}, pages = {123 Seiten}, year = {2024}, abstract = {Incontrare, was {\"u}bersetzt Begegnung bedeutet, ist ein Konferenztischkonzept, der durch seinen modularen Aufbau heraus sticht. Dem Kunden ist es m{\"o}glich das Produkt mit einem einzigen Werkzeug - f{\"u}nfer Imbusschl{\"u}ssel - aufzubauen. Der modulare Aufbau bietet die M{\"o}glichkeit kundenorientiert ein Produkt zusammensetzen zu k{\"o}nnen. Incontrare bietet hierdurch eine Vielzahl an Variationen, die nicht nur die gestalterischen Aspekte anspricht, sondern auch verschiedene Preisklassen abdeckt. Incontrare ist ein Tischkonzept, das sowohl im niederpreisigen , sowie auch im HighEnd Bereich funktioniert.}, language = {de} } @article{AkimbekovDigelTastambeketal.2024, author = {Akimbekov, Nuraly S. and Digel, Ilya and Tastambek, Kuanysh T. and Kozhahmetova, Marzhan and Sherelkhan, Dinara K. and Tauanov, Zhandos}, title = {Hydrogenotrophic methanogenesis in coal-bearing environments: Methane production, carbon sequestration, and hydrogen availability}, series = {International Journal of Hydrogen Energy}, volume = {52}, journal = {International Journal of Hydrogen Energy}, number = {Part D}, publisher = {Elsevier}, address = {New York}, issn = {1879-3487 (online)}, doi = {10.1016/j.ijhydene.2023.09.223}, pages = {1264 -- 1277}, year = {2024}, abstract = {Methane is a valuable energy source helping to mitigate the growing energy demand worldwide. However, as a potent greenhouse gas, it has also gained additional attention due to its environmental impacts. The biological production of methane is performed primarily hydrogenotrophically from H2 and CO2 by methanogenic archaea. Hydrogenotrophic methanogenesis also represents a great interest with respect to carbon re-cycling and H2 storage. The most significant carbon source, extremely rich in complex organic matter for microbial degradation and biogenic methane production, is coal. Although interest in enhanced microbial coalbed methane production is continuously increasing globally, limited knowledge exists regarding the exact origins of the coalbed methane and the associated microbial communities, including hydrogenotrophic methanogens. Here, we give an overview of hydrogenotrophic methanogens in coal beds and related environments in terms of their energy production mechanisms, unique metabolic pathways, and associated ecological functions.}, language = {en} } @masterthesis{Vervekina2024, type = {Bachelor Thesis}, author = {Vervekina, Tatyana}, title = {Designing for Focus : ein Hilfsmittelsystem f{\"u}r Kinder mit AD(H)S}, publisher = {FH Aachen}, address = {Aachen}, pages = {113 Seiten}, year = {2024}, abstract = {Das Projekt widmet sich dem Thema der Aufmerksamkeitsdefizit-Hyperaktivit{\"a}tsst{\"o}rung (ADHS) und Aufmerksamkeitsdefizitst{\"o}rung (ADS) im Kindesalter. Es setzt sich dabei mit den t{\"a}glichen Herausforderungen auseinander, mit denen diese Kinder sowohl im Lernprozess als auch in der famili{\"a}ren Beziehungsdynamik konfrontiert sind. Der entwickelte Konzentrationsbegleiter und das dazugeh{\"o}rige Set basieren auf einer lerntherapeutischen Idee, die ein Gleichgewicht zwischen Konzentration und Entspannung erschafft. Das Gesamtsystem „MonKo" bietet mit dem Konzentrationsbegleiter Unterst{\"u}tzung bei der Alltagsplanung, Priorisierung von Aufgaben und dem Umgang mit Reizen. Der Entspannungsteil des Sets pr{\"a}sentiert sich als „Schatzkiste" mit sensorischen Spielzeugen und ist individuell von Therapeut:innen und Lehrkr{\"a}ften an die Bed{\"u}rfnisse der Kinder anpassbar. Der Konzentrationsbegleiter in der Optik eines liebevollen Monsters soll den Kindern helfen, mit den Herausforderungen neuroatypischen Verhaltens umzugehen und erfolgreich in Schule und Alltag zu sein.}, language = {de} } @masterthesis{vanderBeek2024, type = {Bachelor Thesis}, author = {van der Beek, Lucas}, title = {PRO+SOUND : Kombinationsprodukt bestehend aus Lautsprecher und Projektor}, publisher = {FH Aachen}, address = {Aachen}, pages = {105 Seiten}, year = {2024}, abstract = {PRO+SOUND ist ein tragbares Kombinationsprodukt, bestehend aus Lautsprecher und Projektor, das sowohl privat zum streamen von Filmen, Serien, Musik und Videospielen als auch professionell als Pr{\"a}sentationsger{\"a}t in H{\"o}rs{\"a}len und Konferenzr{\"a}umen genutzt werden kann. Projektoren und Beamer sind groß, schwer, unhandlich und nicht mehr zeitgem{\"a}ß. Die Bedienung der meisten Beamer ist veraltet und kaum digitalisiert. PRO+SOUND l{\"o}st diese Schwachstellen in einem kompakten Produkt und macht das streamen von Inhalten m{\"u}helos und kabellos. Das geringe Gewicht und der kompakte Formfaktor macht die Mitnahme f{\"u}r unterwegs problemlos m{\"o}glich.}, language = {de} } @article{PieronekKleefeld2024, author = {Pieronek, Lukas and Kleefeld, Andreas}, title = {On trajectories of complex-valued interior transmission eigenvalues}, series = {Inverse problems and imaging : IPI}, volume = {18}, journal = {Inverse problems and imaging : IPI}, number = {2}, publisher = {AIMS}, address = {Springfield, Mo}, issn = {1930-8337 (Print)}, doi = {10.3934/ipi.2023041}, pages = {480 -- 516}, year = {2024}, abstract = {This paper investigates the interior transmission problem for homogeneous media via eigenvalue trajectories parameterized by the magnitude of the refractive index. In the case that the scatterer is the unit disk, we prove that there is a one-to-one correspondence between complex-valued interior transmission eigenvalue trajectories and Dirichlet eigenvalues of the Laplacian which turn out to be exactly the trajectorial limit points as the refractive index tends to infinity. For general simply-connected scatterers in two or three dimensions, a corresponding relation is still open, but further theoretical results and numerical studies indicate a similar connection.}, language = {en} } @article{OehlenschlaegerVolkmarStiefelmaieretal.2024, author = {Oehlenschl{\"a}ger, Katharina and Volkmar, Marianne and Stiefelmaier, Judith and Langsdorf, Alexander and Holtmann, Dirk and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum}, series = {Applied Microbiology and Biotechnology}, volume = {108}, journal = {Applied Microbiology and Biotechnology}, publisher = {Springer}, address = {Berlin, Heidelberg}, issn = {1432-0614}, doi = {10.1007/s00253-023-12981-8}, pages = {10 Seiten}, year = {2024}, abstract = {Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes. However, existing publications usually concentrate on the cultivation conditions of the main culture. In this paper, the influence of cryo-conservation and pre-culture on growth and solvent production in the resulting main cultivation are examined. A protocol was developed that leads to reproducible cultivations of Clostridium acetobutylicum. Detailed investigation of the cell conservation in cryo-cultures ensured reliable cell growth in the pre-culture. Moreover, a reason for the acid crash in the main culture was found, based on the cultivation conditions of the pre-culture. The critical parameter to avoid the acid crash and accomplish the shift to the solventogenesis of clostridia is the metabolic phase in which the cells of the pre-culture were at the time of inoculation of the main culture; this depends on the cultivation time of the pre-culture. Using cells from the exponential growth phase to inoculate the main culture leads to an acid crash. To achieve the solventogenic phase with butanol production, the inoculum should consist of older cells which are in the stationary growth phase. Considering these parameters, which affect the entire cultivation process, reproducible results and reliable solvent production are ensured.}, language = {en} } @techreport{HoffmannUllrich2024, type = {Working Paper}, author = {Hoffmann, Sarah and Ullrich, Anna Valentine}, title = {30 Minuten FDM f{\"u}r HAW. Ein Informationsformat f{\"u}r Forschende an HAW in NRW}, doi = {10.5281/zenodo.12569282}, pages = {1 Seite}, year = {2024}, abstract = {Wie kann man das Thema Forschungsdatenmanagement (FDM) konkret und anwendbar f{\"u}r Forschende gestalten, die bisher noch wenig Kontakt damit hatten? Auf diese Frage gibt das Konzept „30 Minuten FDM f{\"u}r HAW. Ein Informationsformat f{\"u}r Forschende an HAW in NRW" eine Antwort. Es entstand als Projektarbeit im Zertifikatskurs Forschungsdatenmanagement 2023/24}, language = {de} } @techreport{BirmansSchickTamborninoetal.2024, type = {Working Paper}, author = {Birmans, Katrin and Schick, Elena and Tambornino, Philipp and Ullrich, Anna Valentine}, title = {Ingenieurwissenschaften im Fokus: Zug{\"a}nge zu einem effektiven Forschungsdatenmanagement an HAW}, doi = {10.5281/zenodo.12545429}, pages = {49 Seiten}, year = {2024}, abstract = {Im Rahmen der Love Data Week vom 12. bis 16.02.2024 haben die BMBF-Projekte FDM2_TH_Koeln der TH K{\"o}ln (FK 16FDFH105) und Persist@HAW der FH Aachen (FK 16FDFH129) am 15.02.2024 gemeinsam eine Online-Veranstaltung mit dem Titel „Ingenieurwissenschaften im Fokus: Zug{\"a}nge zu einem effektiven Forschungsdatenmanagement an HAW" angeboten. Diese richtete sich an Forschende aus den Ingenieurwissenschaften, die einen ersten Zugang zum Thema Forschungsdatenmanagement (FDM) suchen und erfahren m{\"o}chten, welche speziellen Angebote f{\"u}r die Daten aus den Ingenieurwissenschaften existieren. In der Veranstaltung wurden wesentliche Aspekte des Forschungsdatenmanagements entlang des Datenlebenszyklus beleuchtet. Ziel war es, den Teilnehmenden praxisnahe Einblicke und Hilfestellungen zu einem effektiven Umgang mit Forschungsdaten an Hochschulen f{\"u}r Angewandte Wissenschaften (HAW) zu bieten. Durch Beispiele und konkrete Empfehlungen wurde das Thema zug{\"a}nglich gemacht.}, language = {de} } @article{WindmuellerSchapsZantisetal.2024, author = {Windm{\"u}ller, Anna and Schaps, Kristian and Zantis, Frederik and Domgans, Anna and Taklu, Bereket Woldegbreal and Yang, Tingting and Tsai, Chih-Long and Schierholz, Roland and Yu, Shicheng and Kungl, Hans and Tempel, Hermann and Dunin-Borkowski, Rafal E. and H{\"u}ning, Felix and Hwang, Bing Joe and Eichel, R{\"u}diger-A.}, title = {Electrochemical activation of LiGaO2: implications for ga-doped garnet solid electrolytes in li-metal batteries}, series = {ACS Applied Materials \& Interfaces}, volume = {16}, journal = {ACS Applied Materials \& Interfaces}, number = {30}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {39181-3919}, doi = {10.1021/acsami.4c03729}, pages = {14 Seiten}, year = {2024}, abstract = {Ga-doped Li7La3Zr2O12 garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO2 coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO2 in the electrochemical cell and its electrochemical properties is still lacking. Here, we are investigating the electrochemical properties of LiGaO2 through electrochemical tests in galvanostatic cells versus Li metal and complementary ex situ studies via confocal Raman microscopy, quantitative phase analysis based on powder X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron energy loss spectroscopy. The results demonstrate considerable and surprising electrochemical activity, with high reversibility. A three-stage reaction mechanism is derived, including reversible electrochemical reactions that lead to the formation of highly electronically conducting products. The results have considerable implications for the use of Ga-doped Li7La3Zr2O12 electrolytes in all-solid-state Li-metal battery applications and raise the need for advanced materials engineering to realize Ga-doped Li7La3Zr2O12for practical use.}, language = {en} } @article{EichlerBalcBremenetal.2024, author = {Eichler, Fabian and Balc, Nicolae and Bremen, Sebastian and Nink, Philipp}, title = {Investigation of laser powder bed fusion parameters with respect to their influence on the thermal conductivity of 316L samples}, series = {Journal of Manufacturing and Materials Processing}, volume = {8}, journal = {Journal of Manufacturing and Materials Processing}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2504-4494}, doi = {10.3390/jmmp8040166}, pages = {12 Seiten}, year = {2024}, abstract = {The thermal conductivity of components manufactured using Laser Powder Bed Fusion (LPBF), also called Selective Laser Melting (SLM), plays an important role in their processing. Not only does a reduced thermal conductivity cause residual stresses during the process, but it also makes subsequent processes such as the welding of LPBF components more difficult. This article uses 316L stainless steel samples to investigate whether and to what extent the thermal conductivity of specimens can be influenced by different LPBF parameters. To this end, samples are set up using different parameters, orientations, and powder conditions and measured by a heat flow meter using stationary analysis. The heat flow meter set-up used in this study achieves good reproducibility and high measurement accuracy, so that comparative measurements between the various LPBF influencing factors to be tested are possible. In summary, the series of measurements show that the residual porosity of the components has the greatest influence on conductivity. The degradation of the powder due to increased recycling also appears to be detectable. The build-up direction shows no detectable effect in the measurement series.}, language = {en} }