@article{AdelsElbersDiehletal.2023, author = {Adels, Klaudia and Elbers, Gereon and Diehl, Bernd and Monakhova, Yulia}, title = {Multicomponent analysis of dietary supplements containing glucosamine and chondroitin: comparative low- and high-field NMR spectroscopic study}, series = {Analytical Sciences}, volume = {2023}, journal = {Analytical Sciences}, publisher = {Springer Verlag}, address = {Cham}, issn = {1348-2246 (Online)}, doi = {10.1007/s44211-023-00433-2}, pages = {13 Seiten}, year = {2023}, abstract = {With the prevalence of glucosamine- and chondroitin-containing dietary supplements for people with osteoarthritis in the marketplace, it is important to have an accurate and reproducible analytical method for the quantitation of these compounds in finished products. NMR spectroscopic method based both on low- (80 MHz) and high- (500-600 MHz) field NMR instrumentation was established, compared and validated for the determination of chondroitin sulfate and glucosamine in dietary supplements. The proposed method was applied for analysis of 20 different dietary supplements. In the majority of cases, quantification results obtained on the low-field NMR spectrometer are similar to those obtained with high-field 500-600 MHz NMR devices. Validation results in terms of accuracy, precision, reproducibility, limit of detection and recovery demonstrated that the developed method is fit for purpose for the marketed products. The NMR method was extended to the analysis of methylsulfonylmethane, adulterant maltodextrin, acetate and inorganic ions. Low-field NMR can be a quicker and cheaper alternative to more expensive high-field NMR measurements for quality control of the investigated dietary supplements. High-field NMR instrumentation can be more favorable for samples with complex composition due to better resolution, simultaneously giving the possibility of analysis of inorganic species such as potassium and chloride.}, language = {en} } @article{AkimbekovMansurovJandosovetal.2013, author = {Akimbekov, Nuraly Shardarbekovich and Mansurov, Zulkhair and Jandosov, J. and Digel, Ilya and Gossmann, Matthias and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A.}, title = {Wound healing activity of carbonized rice husk}, publisher = {Trans Tech Publications, Switzerland}, address = {B{\"a}ch}, year = {2013}, abstract = {The carbonized rice husk (CRH) was evaluated for its wound healing activity in rats using excision models. In this study, the influences of CRH on wound healing in rat skin in vivo and cellular behavior of human dermal fibroblasts in vitro were investigated. The obtained results showed that the CRH treatment promoted wound epithelization in rats and exhibited moderate inhibition of cell proliferation in vitro. CRH with lanolin oil treated wounds were found to epithelize faster as compared to controls.}, subject = {Wundheilung}, language = {en} } @article{AlexyukBogoyavlenskiyAlexyuketal.2021, author = {Alexyuk, Madina and Bogoyavlenskiy, Andrey and Alexyuk, Pavel and Moldakhanov, Yergali and Berezin, Vladimir and Digel, Ilya}, title = {Epipelagic microbiome of the Small Aral Sea: Metagenomic structure and ecological diversity}, series = {MicrobiologyOpen}, volume = {10}, journal = {MicrobiologyOpen}, number = {1}, publisher = {Wiley}, address = {Weinheim}, issn = {2045-8827}, doi = {10.1002/mbo3.1142}, pages = {1 -- 10}, year = {2021}, abstract = {Microbial diversity studies regarding the aquatic communities that experienced or are experiencing environmental problems are essential for the comprehension of the remediation dynamics. In this pilot study, we present data on the phylogenetic and ecological structure of microorganisms from epipelagic water samples collected in the Small Aral Sea (SAS). The raw data were generated by massive parallel sequencing using the shotgun approach. As expected, most of the identified DNA sequences belonged to Terrabacteria and Actinobacteria (40\% and 37\% of the total reads, respectively). The occurrence of Deinococcus-Thermus, Armatimonadetes, Chloroflexi in the epipelagic SAS waters was less anticipated. Surprising was also the detection of sequences, which are characteristic for strict anaerobes—Ignavibacteria, hydrogen-oxidizing bacteria, and archaeal methanogenic species. We suppose that the observed very broad range of phylogenetic and ecological features displayed by the SAS reads demonstrates a more intensive mixing of water masses originating from diverse ecological niches of the Aral-Syr Darya River basin than presumed before.}, language = {en} } @article{AlnemerKotliarNeuhausetal.2023, author = {Alnemer, Momin Sami Mohammad and Kotliar, Konstantin and Neuhaus, Valentin and Pape, Hans-Christoph and Ciritsis, Bernhard D.}, title = {Cost-effectiveness analysis of surgical proximal femur fracture prevention in elderly: a Markov cohort simulation model}, series = {Cost Effectiveness and Resource Allocation}, journal = {Cost Effectiveness and Resource Allocation}, number = {21, Article number: 77}, publisher = {Springer Nature}, issn = {1478-7547}, doi = {10.1186/s12962-023-00482-4}, pages = {12 Seiten}, year = {2023}, abstract = {Background Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices. Methods This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare \& Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10\% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results. Results With a 10\% fracture risk reduction, model A costs between \$8,850 and \$46,940 per quality-adjusted life-year (\$/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8\% is needed for prophylaxis to be definitely cost-effective. The cost-effectiveness at the secondary prevention level was most sensitive to the cost of the contralateral side's prophylaxis, the patient's age, and fracture treatment cost. For high-risk patients with no fracture history, the cost-effectiveness of a preventive strategy depends on their risk profile. In the baseline analysis, the incremental cost-effectiveness ratio at the primary prevention level varied between \$11,000/QALY and \$74,000/QALY, which is below the defined willingness to pay threshold. Conclusion Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks.}, language = {en} } @article{BaroudWuBohneretal.2003, author = {Baroud, G. and Wu, J.Z. and Bohner, M and Sponagel, Stefan and Steffen, T.}, title = {How to determine the permeability for cement infiltration into osteoporotic cancellous bone}, series = {Medical Engineering \& Physics. 25 (2003), H. 4}, journal = {Medical Engineering \& Physics. 25 (2003), H. 4}, issn = {1350-4533}, pages = {283 -- 288}, year = {2003}, abstract = {Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63\% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.}, subject = {Osteoporose}, language = {en} } @article{BassamArtmannHescheleretal.2011, author = {Bassam, Rasha and Artmann, Gerhard and Hescheler, J{\"u}rgen and Graef, T. and Temiz Artmann, Ayseg{\"u}l and Porst, Dariusz and Linder, Peter and Kayser, Peter and Arinkin, Vladimir and Gossmann, Matthias and Digel, Ilya}, title = {Alterations in human hemoglobin structure related to red blood cell storage}, year = {2011}, abstract = {The importance of the availability of stored blood or blood cells, respectively, for urgent transfusion cannot be overestimated. Nowadays, blood storage becomes even more important since blood products are used for epidemiological studies, bio-technical research or banked for transfusion purposes. Thus blood samples must not only be processed, stored, and shipped to preserve their efficacy and safety, but also all parameters of storage must be recorded and reported for Quality Assurance. Therefore, blood banks and clinical research facilities are seeking more accurate, automated means for blood storage and blood processing.}, subject = {H{\"a}moglobin}, language = {en} } @article{BlankeHagenkampDoeringetal.2021, author = {Blanke, Tobias and Hagenkamp, Markus and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Reger, Vitali and Kuhnhenne, Markus}, title = {Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates}, series = {Geothermal Energy}, volume = {9}, journal = {Geothermal Energy}, number = {Article number: 19}, publisher = {Springer}, address = {Berlin}, issn = {2195-9706}, doi = {10.1186/s40517-021-00201-3}, pages = {23 Seiten}, year = {2021}, abstract = {Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellstr{\"o}m's borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54\% of the outer pipe radius for laminar fow and 60\% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth's thermal properties and the fow type. Conclusively, coaxial geothermal probes' design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.}, language = {en} } @article{BlassUibel2009, author = {Blaß, Hans Joachim and Uibel, Thomas}, title = {Bemessungsvorschl{\"a}ge f{\"u}r Verbindungsmittel in Brettsperrholz}, series = {Bauen mit Holz}, volume = {111}, journal = {Bauen mit Holz}, number = {2}, publisher = {Rudolf M{\"u}ller}, address = {K{\"o}ln}, issn = {0005-6545}, pages = {46 -- 53}, year = {2009}, language = {de} } @article{BlockMayWetzeletal.2023, author = {Block, Franziska and May, Alexander and Wetzel, Katharina and Adels, Klaudia and Elbers, Gereon and Schulze, Margit and Monakhova, Yulia}, title = {What is the best spectroscopic method for simultaneous analysis of organic acids and (poly)saccharides in biological matrices: Example of Aloe vera extracts?}, series = {Talanta Open}, volume = {7}, journal = {Talanta Open}, number = {Art. No. 100220}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2666-8319}, doi = {10.1016/j.talo.2023.100220}, pages = {1 -- 9}, year = {2023}, abstract = {Several species of (poly)saccharides and organic acids can be found often simultaneously in various biological matrices, e.g., fruits, plant materials, and biological fluids. The analysis of such matrices sometimes represents a challenging task. Using Aloe vera (A. vera) plant materials as an example, the performance of several spectro-scopic methods (80 MHz benchtop NMR, NIR, ATR-FTIR and UV-vis) for the simultaneous analysis of quality parameters of this plant material was compared. The determined parameters include (poly)saccharides such as aloverose, fructose and glucose as well as organic acids (malic, lactic, citric, isocitric, acetic, fumaric, benzoic and sorbic acids). 500 MHz NMR and high-performance liquid chromatography (HPLC) were used as the reference methods. UV-vis data can be used only for identification of added preservatives (benzoic and sorbic acids) and drying agent (maltodextrin) and semiquantitative analysis of malic acid. NIR and MIR spectroscopies combined with multivariate regression can deliver more informative overview of A. vera extracts being able to additionally quantify glucose, aloverose, citric, isocitric, malic, lactic acids and fructose. Low-field NMR measurements can be used for the quantification of aloverose, glucose, malic, lactic, acetic, and benzoic acids. The benchtop NMR method was successfully validated in terms of robustness, stability, precision, reproducibility and limit of detection (LOD) and quantification (LOQ), respectively. All spectroscopic techniques are useful for the screening of (poly)saccharides and organic acids in plant extracts and should be applied according to its availability as well as information and confidence required for the specific analytical goal. Benchtop NMR spectroscopy seems to be the most feasible solution for quality control of A. vera products.}, language = {en} } @article{BogoyavlenskiyDigelBerezin1997, author = {Bogoyavlenskiy, A. P. and Digel, Ilya and Berezin, V. E.}, title = {Assessment of dot-blot ELISA sensitivity on membrane sorbent using various peroxidase substrates}, year = {1997}, abstract = {The sensitivity of the peroxidase reaction in dot-blot ELISA significantly depends on the substrate. The highest sensitivity is observed using benzidine and diamine- phenol combinations as the substrates due to the reaction of the coupled oxidation (NADI)}, subject = {Enzyme-linked immunosorbent assay}, language = {en} } @article{BornheimGriegerBlanecketal.2024, author = {Bornheim, Tobias and Grieger, Niklas and Blaneck, Patrick Gustav and Bialonski, Stephan}, title = {Speaker Attribution in German Parliamentary Debates with QLoRA-adapted Large Language Models}, series = {Journal for language technology and computational linguistics : JLCL}, volume = {37}, journal = {Journal for language technology and computational linguistics : JLCL}, number = {1}, publisher = {Gesellschaft f{\"u}r Sprachtechnologie und Computerlinguistik}, address = {Regensburg}, issn = {2190-6858}, doi = {10.21248/jlcl.37.2024.244}, pages = {13 Seiten}, year = {2024}, abstract = {The growing body of political texts opens up new opportunities for rich insights into political dynamics and ideologies but also increases the workload for manual analysis. Automated speaker attribution, which detects who said what to whom in a speech event and is closely related to semantic role labeling, is an important processing step for computational text analysis. We study the potential of the large language model family Llama 2 to automate speaker attribution in German parliamentary debates from 2017-2021. We fine-tune Llama 2 with QLoRA, an efficient training strategy, and observe our approach to achieve competitive performance in the GermEval 2023 Shared Task On Speaker Attribution in German News Articles and Parliamentary Debates. Our results shed light on the capabilities of large language models in automating speaker attribution, revealing a promising avenue for computational analysis of political discourse and the development of semantic role labeling systems.}, language = {en} } @article{CapitainWagnerHummeletal.2021, author = {Capitain, Charlotte and Wagner, Sebastian and Hummel, Joana and Tippk{\"o}tter, Nils}, title = {Investigation of C-N Formation Between Catechols and Chitosan for the Formation of a Strong, Novel Adhesive Mimicking Mussel Adhesion}, series = {Waste and Biomass Valorization}, volume = {12}, journal = {Waste and Biomass Valorization}, publisher = {Springer Nature}, address = {Cham}, issn = {1877-265X}, doi = {10.1007/s12649-020-01110-5}, pages = {1761 -- 1779}, year = {2021}, language = {en} } @article{CheenakulaHoffstadtKrafftetal.2022, author = {Cheenakula, Dheeraja and Hoffstadt, Kevin and Krafft, Simone and Reinecke, Diana and Klose, Holger and Kuperjans, Isabel and Gr{\"o}mping, Markus}, title = {Anaerobic digestion of algal-bacterial biomass of an Algal Turf Scrubber system}, series = {Biomass Conversion and Biorefinery}, volume = {13}, journal = {Biomass Conversion and Biorefinery}, publisher = {Springer}, address = {Berlin}, issn = {2190-6823}, doi = {10.1007/s13399-022-03236-z}, pages = {15 Seiten}, year = {2022}, abstract = {This study investigated the anaerobic digestion of an algal-bacterial biofilm grown in artificial wastewater in an Algal Turf Scrubber (ATS). The ATS system was located in a greenhouse (50°54′19ʺN, 6°24′55ʺE, Germany) and was exposed to seasonal conditions during the experiment period. The methane (CH4) potential of untreated algal-bacterial biofilm (UAB) and thermally pretreated biofilm (PAB) using different microbial inocula was determined by anaerobic batch fermentation. Methane productivity of UAB differed significantly between microbial inocula of digested wastepaper, a mixture of manure and maize silage, anaerobic sewage sludge, and percolated green waste. UAB using sewage sludge as inoculum showed the highest methane productivity. The share of methane in biogas was dependent on inoculum. Using PAB, a strong positive impact on methane productivity was identified for the digested wastepaper (116.4\%) and a mixture of manure and maize silage (107.4\%) inocula. By contrast, the methane yield was significantly reduced for the digested anaerobic sewage sludge (50.6\%) and percolated green waste (43.5\%) inocula. To further evaluate the potential of algal-bacterial biofilm for biogas production in wastewater treatment and biogas plants in a circular bioeconomy, scale-up calculations were conducted. It was found that a 0.116 km2 ATS would be required in an average municipal wastewater treatment plant which can be viewed as problematic in terms of space consumption. However, a substantial amount of energy surplus (4.7-12.5 MWh a-1) can be gained through the addition of algal-bacterial biomass to the anaerobic digester of a municipal wastewater treatment plant. Wastewater treatment and subsequent energy production through algae show dominancy over conventional technologies.}, language = {en} } @article{CheenakulaPaulsenOttetal.2023, author = {Cheenakula, Dheeraja and Paulsen, Svea and Ott, Fabian and Gr{\"o}mping, Markus}, title = {Operational window of a deammonifying sludge for mainstream application in a municipal wastewater treatment plant}, series = {Water and Environment Journal}, journal = {Water and Environment Journal}, number = {Early View}, publisher = {Wiley}, address = {Chichester}, issn = {1747-6593}, doi = {10.1111/wej.12898}, pages = {1 -- 12}, year = {2023}, abstract = {The present work aimed to study the mainstream feasibility of the deammonifying sludge of side stream of municipal wastewater treatment plant (MWWTP) in Kaster, Germany. For this purpose, the deammonifying sludge available at the side stream was investigated for nitrogen (N) removal with respect to the operational factors temperature (15-30°C), pH value (6.0-8.0) and chemical oxygen demand (COD)/N ratio (≤1.5-6.0). The highest and lowest N-removal rates of 0.13 and 0.045 kg/(m³ d) are achieved at 30 and 15°C, respectively. Different conditions of pH and COD/N ratios in the SBRs of Partial nitritation/anammox (PN/A) significantly influenced both the metabolic processes and associated N-removal rates. The scientific insights gained from the current work signifies the possibility of mainstream PN/A at WWTPs. The current study forms a solid basis of operational window for the upcoming semi-technical trails to be conducted prior to the full-scale mainstream PN/A at WWTP Kaster and WWTPs globally.}, language = {en} } @article{DachwaldUlamecPostbergetal.2020, author = {Dachwald, Bernd and Ulamec, Stephan and Postberg, Frank and Sohl, Frank and Vera, Jean-Pierre de and Christoph, Waldmann and Lorenz, Ralph D. and Hellard, Hugo and Biele, Jens and Rettberg, Petra}, title = {Key technologies and instrumentation for subsurface exploration of ocean worlds}, series = {Space Science Reviews}, volume = {216}, journal = {Space Science Reviews}, number = {Art. 83}, publisher = {Springer}, address = {Dordrecht}, issn = {1572-9672}, doi = {10.1007/s11214-020-00707-5}, pages = {45}, year = {2020}, abstract = {In this chapter, the key technologies and the instrumentation required for the subsurface exploration of ocean worlds are discussed. The focus is laid on Jupiter's moon Europa and Saturn's moon Enceladus because they have the highest potential for such missions in the near future. The exploration of their oceans requires landing on the surface, penetrating the thick ice shell with an ice-penetrating probe, and probably diving with an underwater vehicle through dozens of kilometers of water to the ocean floor, to have the chance to find life, if it exists. Technologically, such missions are extremely challenging. The required key technologies include power generation, communications, pressure resistance, radiation hardness, corrosion protection, navigation, miniaturization, autonomy, and sterilization and cleaning. Simpler mission concepts involve impactors and penetrators or - in the case of Enceladus - plume-fly-through missions.}, language = {en} } @article{DanielStarck2007, author = {Daniel, Bernd and Starck, Andreas}, title = {Kostenkontrolle und Kostensteuerung im Hochbau}, year = {2007}, abstract = {Textauszug: Nach dem Leistungsbild der HOAI hat der Architekt bei Planung und Baubetrieb vier Stationen der Kostenermittlung entsprechend der DIN 276, Abschnitt 2.3 abzuarbeiten. Der Architekt, der seiner Verantwortung gerecht werden will, wird hier weitere Kontrollmechanismen einbauen wollen. {\"U}ber die genannten Kostenermittlungen hinaus kennt die DIN 276 daher noch das Erfordernis der Kostenkontrolle in Abschnitt 2.4 und der Kostensteuerung in Abschnitt 2.5. Die Kostensteuerung greift immer dann, wenn die Kostenkontrolle eine Abweichung des Kostenrahmens von den Sollwerten aufzeigt. Dazu m{\"u}ssen die Kontrollinstanzen dort eingebaut werden, wo Korrekturen noch m{\"o}glich sind. Eine erste Kontrolle der Kosten ist daher zwischen Massenermittlung und Vergabe sinnvoll einzuflechten. Zu diesem Zeitpunkt kann die Planung noch ver{\"a}ndert werden, was einen ersten steuernden Eingriff in die Baukosten erm{\"o}glicht, und zwar bevor die Angebotsunterlagen verschickt werden. Die Grundlagen zu einer effektiven Kostensteuerung werden in der Mengenermittlung der Leistungsphase 6 gelegt. Wenn dort die Mengen nicht sorgf{\"a}ltig und nachvollziehbar ermittelt wurden, wird der Soll- Ist- Abgleich w{\"a}hrend der Bauphase nicht fr{\"u}hzeitig genug gelingen, wenn nicht gar ganz entfallen. Es gilt also, daf{\"u}r zu sorgen, dass die Mengenermittlung zur Vergabe mit entsprechender Sorgfalt und vor Allem „projektnah" erfolgt. Sch{\"a}tzungen haben hier keine Berechtigung.}, subject = {Projektsteuerung}, language = {de} } @article{DanielStarck2007, author = {Daniel, Bernd and Starck, Andreas}, title = {Die Anwendung der VOB in der baubetrieblichen Praxis}, year = {2007}, abstract = {Eine Einf{\"u}hrung in die Anwendung der VOB in der baubetrieblichen Praxis im Rahmen der erg{\"a}nzenden Schriften zu den Vorlesungen. Die Anwendung der VOB als Vertragsbedingung f{\"u}r einen Bauvertrag ist g{\"a}ngige Praxis, {\"u}ber die der Architekt im Baubetrieb umfassend informiert sein muß. Die Anwendung der VOB im Bauvertrag bedarf der vorherigen Vereinbarung zwischen den Vertragsparteien. Dabei muß die VOB im Ganzen vereinbart werden. Eine Ver{\"a}nderung dieser Bestimmungen f{\"u}hrt zur teilweisen Unwirksamkeit der vertraglichen Vereinbarung. Der Architekt, der f{\"u}r seinen Bauherrn die Vergabeunterlagen zusammenstellen muß, haftet f{\"u}r Fehler bei der Formulierung oder der Zusammenstellung. Es ist daher f{\"u}r den Architekten unerl{\"a}ßlich, die vertraglichen Zusammenh{\"a}nge zu kennen. Dieser Fachaufsatz soll zu einem sicheren Umgang mit der VOB als Vertragsgrundlage beitragen.}, subject = {Baubetrieb}, language = {de} } @article{DickWagnerRoeth2005, author = {Dick, Angela and Wagner, Manfred and R{\"o}th, Thilo}, title = {Capro Automotive Group FH Aachen}, year = {2005}, abstract = {Design- und Karosseriebaustudenten der FH Aachen entwickeln gemeinsam mit externen Fachleuten unter Einsatz virtueller Entwicklungswerkzeuge ein Konzept f{\"u}r einen Sportwagen}, subject = {Karosseriebau}, language = {de} } @article{DigelAkimbekovRogachevetal.2023, author = {Digel, Ilya and Akimbekov, Nuraly and Rogachev, Evgeniy and Pogorelova, Natalia}, title = {Bacterial cellulose produced by Medusomyces gisevii on glucose and sucrose: biosynthesis and structural properties}, series = {Cellulose}, journal = {Cellulose}, publisher = {Springer Science + Business Media}, address = {Dordrecht}, issn = {1572-882X (Online)}, doi = {10.1007/s10570-023-05592-z}, pages = {15 Seiten}, year = {2023}, abstract = {In this work, the effects of carbon sources and culture media on the production and structural properties of bacterial cellulose (BC) synthesized by Medusomyces gisevii have been studied. The culture medium was composed of different initial concentrations of glucose or sucrose dissolved in 0.4\% extract of plain green tea. Parameters of the culture media (titratable acidity, substrate conversion degree etc.) were monitored daily for 20 days of cultivation. The BC pellicles produced on different carbon sources were characterized in terms of biomass yield, crystallinity and morphology by field emission scanning electron microscopy (FE-SEM), atomic force microscopy and X-ray diffraction. Our results showed that Medusomyces gisevii had higher BC yields in media with sugar concentrations close to 10 g L-1 after a 18-20 days incubation period. Glucose in general lead to a higher BC yield (173 g L-1) compared to sucrose (163.5 g L-1). The BC crystallinity degree and surface roughness were higher in the samples synthetized from sucrose. Obtained FE-SEM micrographs show that the BC pellicles synthesized in the sucrose media contained densely packed tangles of cellulose fibrils whereas the BC produced in the glucose media displayed rather linear geometry of the BC fibrils without noticeable aggregates.}, language = {en} } @article{EggertKling2023, author = {Eggert, Mathias and Kling, Rene}, title = {How to distribute charging requests of electronic vehicles? A reservation-based approach}, series = {International Journal of Intelligent Transportation Systems Research}, volume = {21}, journal = {International Journal of Intelligent Transportation Systems Research}, number = {2023}, publisher = {Springer}, address = {Berlin, Heidelberg, New York}, issn = {1868-8659}, doi = {10.1007/s13177-023-00367-z}, pages = {437 -- 460}, year = {2023}, abstract = {The number of electronic vehicles increase steadily while the space for extending the charging infrastructure is limited. In particular in urban areas, where parking spaces in attractive areas are famous, opportunities to setup new charging stations is very limited. This leads to an overload of some very attractive charging stations and an underutilization of less attractive ones. Against this background, the paper at hand presents the design of an e-vehicle reservation system that aims at distributing the utilization of the charging infrastructure, particularly in urban areas. By applying a design science approach, the requirements for a reservation-based utilization approach are elicited and a model for a suitable distribution approach and its instantiation are developed. The artefact is evaluated by simulating the distribution effects based on data of real charging station utilizations.}, language = {en} } @article{EggertKreuzer2022, author = {Eggert, Mathias and Kreuzer, Vincent}, title = {Sprachsteuerung im Gesundheitswesen - Anforderungen und Auswahl geeigneter Anbieter}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {59}, journal = {HMD Praxis der Wirtschaftsinformatik}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {2198-2775}, issn = {1436-3011}, doi = {10.1365/s40702-022-00919-z}, pages = {1640 -- 1652}, year = {2022}, abstract = {Das Gesundheitswesen ist konfrontiert mit steigenden Kosten und einer immer schwieriger werdenden Personalsituation. Zeitgleich versprechen moderne Sprachsteuerungssysteme Prozesse in Arztpraxen und Krankenh{\"a}usern zu verschlanken und Vorg{\"a}nge zu beschleunigen. Dennoch wird derzeit der Einsatz von Sprachsteuerungssystemen in Arztpraxen oder Krankenh{\"a}usern nur selten beobachtet, was auch an den besonders strengen Datenschutzauflagen der Datenschutzgrundverordnung (DSGVO) liegt. Dar{\"u}ber hinaus wirft die niedrige Nutzungsrate die Frage nach den konkreten Anforderungen und ihrer Umsetzbarkeit auf, was durch den vorliegenden Beitrag adressiert wird, indem die Ergebnisse von Interviews mit acht medizinischen Fachexperten ausgewertet werden. Erg{\"a}nzend wird die technische Umsetzbarkeit einzelner Anforderungen mit unterschiedlichen Cloud-Anbietern erprobt.}, language = {de} } @article{EggertMoulen2020, author = {Eggert, Mathias and Moulen, Tobias}, title = {Selektion von Gesch{\"a}ftsprozessen zur Anwendung von Robotic Process Automation am Beispiel einer Versicherung}, series = {HMD Praxis der Wirtschaftsinformatik}, volume = {57}, journal = {HMD Praxis der Wirtschaftsinformatik}, number = {6}, publisher = {Springer}, address = {Weinheim}, issn = {1436-3011}, doi = {10.1365/s40702-020-00665-0}, pages = {1150 -- 1162}, year = {2020}, abstract = {H{\"a}ufig bremsen geringe IT-Ressourcen, fehlende Softwareschnittstellen oder eine veraltete und komplex gewachsene Systemlandschaft die Automatisierung von Gesch{\"a}ftsprozessen. Robotic Process Automation (RPA) ist eine vielversprechende Methode, um Gesch{\"a}ftsprozesse oberfl{\"a}chenbasiert und ohne gr{\"o}ßere Systemeingriffe zu automatisieren und Medienbr{\"u}che abzubauen. Die Auswahl der passenden Prozesse ist dabei f{\"u}r den Erfolg von RPA-Projekten entscheidend. Der vorliegende Beitrag liefert daf{\"u}r Selektionskriterien, die aus einer qualitativen Inhaltanalyse von elf Interviews mit RPA-Experten aus dem Versicherungsumfeld resultieren. Das Ergebnis umfasst eine gewichtetet Liste von sieben Dimensionen und 51 Prozesskriterien, welche die Automatisierung mit Softwarerobotern beg{\"u}nstigen bzw. deren Nichterf{\"u}llung eine Umsetzung erschweren oder sogar verhindern. Die drei wichtigsten Kriterien zur Auswahl von Gesch{\"a}ftsprozessen f{\"u}r die Automatisierung mittels RPA umfassen die Entlastung der an dem Prozess mitwirkenden Mitarbeiter (Arbeitnehmer{\"u}berlastung), die Ausf{\"u}hrbarkeit des Prozesses mittels Regeln (Regelbasierte Prozessteuerung) sowie ein positiver Kosten-Nutzen-Vergleich. Praktiker k{\"o}nnen diese Kriterien verwenden, um eine systematische Auswahl von RPA-relevanten Prozessen vorzunehmen. Aus wissenschaftlicher Perspektive stellen die Ergebnisse eine Grundlage zur Erkl{\"a}rung des Erfolgs und Misserfolgs von RPA-Projekten dar.}, language = {de} } @article{EngemannCoenenDawaretal.2021, author = {Engemann, Heiko and C{\"o}nen, Patrick and Dawar, Harshal and Du, Shengzhi and Kallweit, Stephan}, title = {A robot-assisted large-scale inspection of wind turbine blades in manufacturing using an autonomous mobile manipulator}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {19}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app11199271}, pages = {1 -- 22}, year = {2021}, abstract = {Wind energy represents the dominant share of renewable energies. The rotor blades of a wind turbine are typically made from composite material, which withstands high forces during rotation. The huge dimensions of the rotor blades complicate the inspection processes in manufacturing. The automation of inspection processes has a great potential to increase the overall productivity and to create a consistent reliable database for each individual rotor blade. The focus of this paper is set on the process of rotor blade inspection automation by utilizing an autonomous mobile manipulator. The main innovations include a novel path planning strategy for zone-based navigation, which enables an intuitive right-hand or left-hand driving behavior in a shared human-robot workspace. In addition, we introduce a new method for surface orthogonal motion planning in connection with large-scale structures. An overall execution strategy controls the navigation and manipulation processes of the long-running inspection task. The implemented concepts are evaluated in simulation and applied in a real-use case including the tip of a rotor blade form.}, language = {en} } @article{Fabo2003, author = {Fabo, Sabine}, title = {Das Museum lebt? Der Diskurs der Vernetzung im virtuellen Kunstraum}, series = {Zeitenblicke}, volume = {2(2003)}, journal = {Zeitenblicke}, number = {1}, year = {2003}, abstract = {Kunstwerke sowie ihre Pr{\"a}sentation und Vermittlung werden zunehmend von digitalen Technologien unterst{\"u}tzt. Virtuelle Ausstellungen, Internet-Projekte und komplexe Datenarchive stellen das Kunstwerk in einen medialen Kontext, der weit {\"u}ber das Moment einer technischen Reproduzierbarkeit hinausgeht. Das allgegenw{\"a}rtige Konzept der Vernetzung dynamisiert Kunst, ihre Rezipienten und Ausstellungsorte. Die Beziehungen zwischen diesen Feldern werden mit Hilfe physiologischer Metaphern definiert und visualisiert. Fr{\"u}here Speicher und Archive geraten in einen prozessualen Sog, in dem alles fluktuiert, sich kurzweilig verkn{\"u}pft, aufl{\"o}st und in permanente Dialoge mit seiner Umgebung tritt - das virtuelle Museum ger{\"a}t in aktuellen Standortbestimmungen in die definitorische N{\"a}he des K{\"u}nstlichen Lebens.}, subject = {Elektronische Kunst}, language = {de} } @article{FalkenbergKohnBottetal.2023, author = {Falkenberg, Fabian and Kohn, Sophie and Bott, Michael and Bongaerts, Johannes and Siegert, Petra}, title = {Biochemical characterisation of a novel broad pH spectrum subtilisin from Fictibacillus arsenicus DSM 15822ᵀ}, series = {FEBS Open Bio}, volume = {13}, journal = {FEBS Open Bio}, number = {11}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {2211-5463}, doi = {10.1002/2211-5463.13701}, pages = {2035 -- 2046}, year = {2023}, abstract = {Subtilisins from microbial sources, especially from the Bacillaceae family, are of particular interest for biotechnological applications and serve the currently growing enzyme market as efficient and novel biocatalysts. Biotechnological applications include use in detergents, cosmetics, leather processing, wastewater treatment and pharmaceuticals. To identify a possible candidate for the enzyme market, here we cloned the gene of the subtilisin SPFA from Fictibacillus arsenicus DSM 15822ᵀ (obtained through a data mining-based search) and expressed it in Bacillus subtilis DB104. After production and purification, the protease showed a molecular mass of 27.57 kDa and a pI of 5.8. SPFA displayed hydrolytic activity at a temperature optimum of 80 °C and a very broad pH optimum between 8.5 and 11.5, with high activity up to pH 12.5. SPFA displayed no NaCl dependence but a high NaCl tolerance, with decreasing activity up to concentrations of 5 m NaCl. The stability enhanced with increasing NaCl concentration. Based on its substrate preference for 10 synthetic peptide 4-nitroanilide substrates with three or four amino acids and its phylogenetic classification, SPFA can be assigned to the subgroup of true subtilisins. Moreover, SPFA exhibited high tolerance to 5\% (w/v) SDS and 5\% H₂O₂ (v/v). The biochemical properties of SPFA, especially its tolerance of remarkably high pH, SDS and H₂O₂, suggest it has potential for biotechnological applications.}, language = {en} } @article{FalkenbergRahbaFischeretal.2022, author = {Falkenberg, Fabian and Rahba, Jade and Fischer, David and Bott, Michael and Bongaerts, Johannes and Siegert, Petra}, title = {Biochemical characterization of a novel oxidatively stable, halotolerant, and high-alkaline subtilisin from Alkalihalobacillus okhensis Kh10-101T}, series = {FEBS Open Bio}, volume = {12}, journal = {FEBS Open Bio}, number = {10}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {2211-5463}, doi = {10.1002/2211-5463.13457}, pages = {1729 -- 1746}, year = {2022}, abstract = {Halophilic and halotolerant microorganisms represent a promising source of salt-tolerant enzymes suitable for various biotechnological applications where high salt concentrations would otherwise limit enzymatic activity. Considering the current growing enzyme market and the need for more efficient and new biocatalysts, the present study aimed at the characterization of a high-alkaline subtilisin from Alkalihalobacillus okhensis Kh10-101T. The protease gene was cloned and expressed in Bacillus subtilis DB104. The recombinant protease SPAO with 269 amino acids belongs to the subfamily of high-alkaline subtilisins. The biochemical characteristics of purified SPAO were analyzed in comparison with subtilisin Carlsberg, Savinase, and BPN'. SPAO, a monomer with a molecular mass of 27.1 kDa, was active over a wide range of pH 6.0-12.0 and temperature 20-80 °C, optimally at pH 9.0-9.5 and 55 °C. The protease is highly oxidatively stable to hydrogen peroxide and retained 58\% of residual activity when incubated at 10 °C with 5\% (v/v) H2O2 for 1 h while stimulated at 1\% (v/v) H2O2. Furthermore, SPAO was very stable and active at NaCl concentrations up to 5.0 m. This study demonstrates the potential of SPAO for biotechnological applications in the future.}, language = {en} } @article{FalkenbergVossBottetal.2023, author = {Falkenberg, Fabian and Voß, Leonie and Bott, Michael and Bongaerts, Johannes and Siegert, Petra}, title = {New robust subtilisins from halotolerant and halophilic Bacillaceae}, series = {Applied Microbiology and Biotechnology}, volume = {107}, journal = {Applied Microbiology and Biotechnology}, publisher = {Springer Nature}, address = {Berlin}, issn = {1432-0614}, doi = {10.1007/s00253-023-12553-w}, pages = {3939 -- 3954}, year = {2023}, abstract = {The aim of the present study was the characterisation of three true subtilisins and one phylogenetically intermediate subtilisin from halotolerant and halophilic microorganisms. Considering the currently growing enzyme market for efficient and novel biocatalysts, data mining is a promising source for novel, as yet uncharacterised enzymes, especially from halophilic or halotolerant Bacillaceae, which offer great potential to meet industrial needs. Both halophilic bacteria Pontibacillus marinus DSM 16465ᵀ and Alkalibacillus haloalkaliphilus DSM 5271ᵀ and both halotolerant bacteria Metabacillus indicus DSM 16189 and Litchfieldia alkalitelluris DSM 16976ᵀ served as a source for the four new subtilisins SPPM, SPAH, SPMI and SPLA. The protease genes were cloned and expressed in Bacillus subtilis DB104. Purification to apparent homogeneity was achieved by ethanol precipitation, desalting and ion-exchange chromatography. Enzyme activity could be observed between pH 5.0-12.0 with an optimum for SPPM, SPMI and SPLA around pH 9.0 and for SPAH at pH 10.0. The optimal temperature for SPMI and SPLA was 70 °C and for SPPM and SPAH 55 °C and 50 °C, respectively. All proteases showed high stability towards 5\% (w/v) SDS and were active even at NaCl concentrations of 5 M. The four proteases demonstrate potential for future biotechnological applications.}, language = {en} } @article{FiedlerHennMelcher2014, author = {Fiedler, Gerda and Henn, Gudrun and Melcher, Karin}, title = {ANPAK - ein semesterbegleitender Anpassungskurs}, series = {Zeitschrift f{\"u}r Hochschulentwicklung}, volume = {9}, journal = {Zeitschrift f{\"u}r Hochschulentwicklung}, number = {4}, publisher = {{\"O}GHD}, address = {Wien}, issn = {2219-6994}, pages = {85 -- 100}, year = {2014}, abstract = {In Folge mehrj{\"a}hriger statistischer Untersuchungen an der FH Aachen ist unter anderem ein Eingangstest entstanden, der als Diagnosetool f{\"u}r einen erfolgreichen Studieneinstieg verwendet wird. Es hat sich herausgestellt, dass ein Testergebnis von weniger als 25 (von maximal 56 erreichbaren) Punkten die Chance auf einen erfolgreichen Studieneinstieg deutlich verringert. Ungef{\"a}hr die H{\"a}lfte aller Erstsemester hat weniger als 25 Punkte im Eingangstest. Weniger als 20 \% dieser Gruppe bestehen innerhalb eines Jahres die Klausur Mathematik 1. Die investierte Zeit von zwei Semestern ist mit Blick auf den Wissenszuwachs und damit letztendlich den Studienerfolg nicht effizient genutzt. Deshalb haben wir im WS 2013/14 einen semesterbegleitenden Anpassungskurs f{\"u}r diese Gruppe installiert. Ziel eines solchen Kurses ist es, die Student/innen innerhalb eines Jahres in die Lage zu versetzen, nach zwei Semestern problemlos den Vorlesungen in Mathematik zu folgen. Dieser Artikel beschreibt das Konzept dieses Anpassungskurses und zeigt erste Ergebnisse und Probleme des Pilotdurchgangs auf.}, language = {de} } @article{FingerGoettenBraunetal.2020, author = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees}, title = {Mass, primary energy, and cost: the impact of optimization objectives on the initial sizing of hybrid-electric general aviation aircraft}, series = {CEAS Aeronautical Journal}, volume = {2020}, journal = {CEAS Aeronautical Journal}, number = {11}, publisher = {Springer}, address = {Heidelberg}, issn = {1869-5590}, doi = {10.1007/s13272-020-00449-8}, pages = {713 -- 730}, year = {2020}, abstract = {For short take-off and landing (STOL) aircraft, a parallel hybrid-electric propulsion system potentially offers superior performance compared to a conventional propulsion system, because the short-take-off power requirement is much higher than the cruise power requirement. This power-matching problem can be solved with a balanced hybrid propulsion system. However, there is a trade-off between wing loading, power loading, the level of hybridization, as well as range and take-off distance. An optimization method can vary design variables in such a way that a minimum of a particular objective is attained. In this paper, a comparison between the optimization results for minimum mass, minimum consumed primary energy, and minimum cost is conducted. A new initial sizing algorithm for general aviation aircraft with hybrid-electric propulsion systems is applied. This initial sizing methodology covers point performance, mission performance analysis, the weight estimation process, and cost estimation. The methodology is applied to the design of a STOL general aviation aircraft, intended for on-demand air mobility operations. The aircraft is sized to carry eight passengers over a distance of 500 km, while able to take off and land from short airstrips. Results indicate that parallel hybrid-electric propulsion systems must be considered for future STOL aircraft.}, language = {en} } @article{Gebhardt2005, author = {Gebhardt, Andreas}, title = {Rapid Prototyping f{\"u}r metallische Werkst{\"u}cke: Direkte und indirekte Verfahren}, year = {2005}, abstract = {Die generative Herstellung von Kunststoffbauteilen hat im Gewand des Rapid Prototyping die Produktentwicklung nachhaltig positiv beeinflusst und ist im Begriff als Rapid Manufacturing die Fertigung zu revolutionieren. Je mehr sich die besonderen Eigenschaften generativ gefertigter Kunststoffbauteile herumsprechen, desto lauter wird der Ruf nach Metallbauteilen. Die Entwicklung entsprechender Prozesse l{\"a}uft auf Hochtouren, kann aber bisher aber erst vereinzelt Erfolge vorweisen. Dabei w{\"a}ren es gerade die Metallbauteile, die ausgestattet mit den besonderen Merkmalen generativ gefertigter Werkst{\"u}cke, in vielen Branchen einen deutlichen Entwicklungsschub ausl{\"o}sen k{\"o}nnten. F{\"u}r den potenziellen Anwender ist dabei besonders verwirrend, dass die unterschiedlichsten Ans{\"a}tze nebeneinander verfolgt werden. Im Folgenden soll daher der Versuche unternommen werden, dieses weite Feld systematisiert darzustellen und M{\"o}glichkeiten und Trends zu erl{\"a}utern.}, subject = {Rapid prototyping}, language = {de} } @article{Gebhardt2006, author = {Gebhardt, Andreas}, title = {Rapid Manufacturing - eine interdisziplin{\"a}re Strategie}, year = {2006}, abstract = {Als um 1987 ein Verfahren namens Stereolithographie und ein Stereolithography Apparatus (SLA) vorgestellt wurden, war der Traum von der Herstellung beliebiger dreidimensionaler Bauteile direkt aus Computerdaten und ohne bauteilspezifische Werkzeuge Realit{\"a}t geworden. Ein Anwendungs-Szenario wurde gleich mitgeliefert. Diese Technologie w{\"u}rde es m{\"o}glich machen, die gesamte Ersatzteilversorgung der Amerikanischen Pazifikflotte mittels ein paar dieser Maschinen, umfangreicher Datenst{\"a}tze und gen{\"u}gend Rohmaterial vor Ort auf einem Flugzeugtr{\"a}ger direkt nach Bedarf zu fertigen. Diese Vorstellung definierte schon damals die direkte digitale Fertigung, das Rapid Manufacturing. In der Realit{\"a}t bestanden die mit diesem Verfahren hergestellten Bauteile nur aus Kunststoff, waren ungenau, bruchempfindlich und klebrig und allein in der Produktentwicklung, eben als Prototypen zu benutzen. Sie waren schnell verf{\"u}gbar, weil zu Ihrer Herstellung keine Werkzeuge ben{\"o}tigt wurden. Folgerichtige und zudem modern hießen sie: Rapid Prototyping. Rapid Prototyping wurde schnell zum Synonym eines neuen Zweiges der Fertigungstechnik, der Generativen Fertigungstechnik. Die weitere Entwicklung brachte neue Verfahren, h{\"o}here Genauigkeiten, verbesserte Werkstoffe und neue Anwendungen. Die Herstellung von Negativen, also Werkzeugen, mit dem gleichen Verfahren wurde marketing-getrieben Rapid Tooling genannt und als die ersten Bauteile nicht mehr als Prototypen, sondern als Endprodukte eingesetzt wurden, nannte man dies Rapid Manufacturing - das Ziel war erreicht. War das Ziel wirklich erreicht? Ist es Rapid Manufacturing, wenn ein generativ gefertigtes Bauteil die gew{\"u}nschte Spezifikation erreicht? Was muss passieren, damit aus dem Ph{\"a}nomen Rapid Prototyping eine Strategie wird, die geeignet ist, einen Paradigmenwechsel von der heutigen Hersteller-induzierten Massenproduktion von Massenartikeln zur Verbraucher-induzierten (und verantworteten) Massenproduktion von Einzelteilen f{\"u}r jedermann erm{\"o}glichen und m{\"o}glicherweise unsere Arbeits- und Lebensformen tiefgreifend zu beeinflussen? Im Beitrag wird der Begriff der (Fertigungs-) Strategie „Rapid Manufacturing" n{\"a}her beleuchtet. Es wird diskutiert, welche Maßnahmen auf der technischen und der operative Ebene getroffen werden m{\"u}ssen, damit die generative Fertigungstechnik im Sinne dieser Strategie umgesetzt werden kann. Beispiele belegen, dass diese Entwicklung bereits begonnen hat und geben Anregungen f{\"u}r eine konstruktive Diskussion auf der RapidTech 2006.}, subject = {Rapid prototyping}, language = {de} } @article{Gebhardt2006, author = {Gebhardt, Andreas}, title = {Generative Manufacturing of Ceramic Parts "Vision Rapid Prototyping"}, year = {2006}, abstract = {Table of Contents Introduction 1. Generative Manufacturing Processes 2. Classification of Generative Manufacturing Processes 3. Application of Generative Processes on the Fabrication of Ceramic Parts 3.1 Extrusion 3.2 3D-Printing 3.3 Sintering - Laser Sintering 3.4 Layer-Laminate Processes 3.5 Stereolithography (sometimes written: Stereo Lithography) 4. Layer Milling 5. Conclusion - Vision}, subject = {Rapid prototyping}, language = {en} } @article{Gebhardt2004, author = {Gebhardt, Andreas}, title = {Grundlagen des Rapid Prototyping: Eine Kurzdarstellung der Rapid Prototyping Verfahren}, year = {2004}, abstract = {Generative Verfahren sind seit etwa 1987 in den USA und seit etwa 1990 in Europa und Deutschland in Form von Rapid Prototyping Verfahren bekannt und haben sich in dieser Zeit von eher als exotisch anzusehenden Modellbauverfahren zu effizienten Werkzeugen f{\"u}r die Beschleunigung der Produktentstehung gewandelt. Mit der Weiterentwicklung der Verfahren und insbesondere der Materialien wird mehr und mehr das Feld der direkten Anwendung der Rapid Technologie zur Fertigung erschlossen. Rapid Technologien werden daher zum Schl{\"u}ssel f{\"u}r neue Konstruktionssystematiken und Fertigungsstrategien.}, subject = {Rapid prototyping}, language = {de} } @article{GebhardtBrueckerSchmidt2005, author = {Gebhardt, Andreas and Br{\"u}cker, Christoph and Schmidt, Frank-Michael}, title = {RP gest{\"u}tzte Herstellung komplexer transparenter Hohlr{\"a}ume f{\"u}r die Str{\"o}mungsanalyse}, year = {2005}, abstract = {Die Berechnung der Durchstr{\"o}mung von Bauteilen ist gegen{\"u}ber derjenigen von umstr{\"o}mten Bauteilen deutlich im Hintertreffen. Das liegt vor allem an der fehlenden Verf{\"u}gbarkeit geeigneter optisch transparenter Modellkan{\"a}le f{\"u}r die experimentelle Analyse. Der Beitrag stellt ein Verfahren zur Herstellung transparenter durchstr{\"o}mter Geometrien auf der Basis generativ gefertigter Urmodelle vor. Damit k{\"o}nnen beliebig komplexe Innenstr{\"o}mungen optisch analysiert werden. Anhand von zwei Beispielen aus der Medizin, der Modellierung der oberen Atemwege und des Bronchialbaums, wird das Verfahren vorgef{\"u}hrt. Der generative Bauprozess mittels 3D-Printing wird beschrieben und die Abformung in transparentem Silikon gezeigt. Schließlich werden beispielhaft der Messaufbau und Ergebnisse der Anwendung vorgestellt. Das Verfahren bildet die Grundlage f{\"u}r die Analyse und Berechnung komplexer Innenstr{\"o}mungen und tr{\"a}gt somit zur Verbesserung zahlreicher technischer Anwendungen bei.}, subject = {Rapid prototyping}, language = {de} } @article{GeorgStollenwerkReinkensmeieretal.2021, author = {Georg, J{\"o}rg Heiner and Stollenwerk, Dominik and Reinkensmeier, Sebastian and Jungbluth, Christian}, title = {„Smartes" Laden an {\"o}ffentlich zug{\"a}nglichen Lades{\"a}ulen - Teil 1: Quo vadis, Marktdesign?}, series = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, volume = {71}, journal = {Energiewirtschaftliche Tagesfragen : et ; Zeitschrift f{\"u}r Energiewirtschaft, Recht, Technik und Umwelt}, number = {1/2}, publisher = {ETV Energieverlag}, address = {Essen}, isbn = {0720-6240}, issn = {0013-743X}, pages = {64 -- 69}, year = {2021}, language = {de} } @article{GorissenStaatLaack2012, author = {Gorissen, P. and Staat, Manfred and Laack, Walter van}, title = {Experimentelle Kraftmessungen als Beitrag zur Wirksamkeitsbeurteilung von Schienbeinschonern im Fußballsport}, series = {OUP Zeitschrift f{\"u}r die orthop{\"a}dische und unfallchirurgische Praxis}, volume = {1}, journal = {OUP Zeitschrift f{\"u}r die orthop{\"a}dische und unfallchirurgische Praxis}, number = {1}, publisher = {Deutscher {\"A}rzte-Verlag}, address = {K{\"o}ln}, issn = {2193-5785}, doi = {10.3238/oup.2012.0010-0015}, pages = {10 -- 15}, year = {2012}, abstract = {Diese Studie besch{\"a}ftigte sich mit der D{\"a}mpfungswirkung von Schienbeinschonern, wie sie beim Fußball zum Einsatz kommen. Sie wurde mit Hilfe eines Pendelhammers durchgef{\"u}hrt, der verschiedene Aufschlagkr{\"a}fte auf die Schoner erm{\"o}glichte. Dabei wurde deutlich, dass Schienbeinschoner die beste Wirkung bei Maximalkr{\"a}ften unterhalb von 5kN erreichen k{\"o}nnen, dass bei gr{\"o}ßerer Belastung allerdings Verbesserungsbedarf besteht. Hierf{\"u}r konnte, u.a. durch den Einsatz neuer Materialien, ein guter Ansatzpunkt im „ad{\"a}quaten Zusammenspiel von Schale und Polsterung" der Schoner gefunden werden. Die Untersuchung hat weiterhin gezeigt, dass zumindest teilweise eine deutliche Verbesserung der D{\"a}mpfungswirkung der Schienbeinschoner in den letzten Jahren erreicht werden konnte.}, subject = {Fußball}, language = {de} } @article{GrajewskiKleefeld2023, author = {Grajewski, Matthias and Kleefeld, Andreas}, title = {Detecting and approximating decision boundaries in low-dimensional spaces}, series = {Numerical Algorithms}, volume = {93}, journal = {Numerical Algorithms}, number = {4}, publisher = {Springer Science+Business Media}, address = {Dordrecht}, issn = {1572-9265}, pages = {35 Seiten}, year = {2023}, abstract = {A method for detecting and approximating fault lines or surfaces, respectively, or decision curves in two and three dimensions with guaranteed accuracy is presented. Reformulated as a classification problem, our method starts from a set of scattered points along with the corresponding classification algorithm to construct a representation of a decision curve by points with prescribed maximal distance to the true decision curve. Hereby, our algorithm ensures that the representing point set covers the decision curve in its entire extent and features local refinement based on the geometric properties of the decision curve. We demonstrate applications of our method to problems related to the detection of faults, to multi-criteria decision aid and, in combination with Kirsch's factorization method, to solving an inverse acoustic scattering problem. In all applications we considered in this work, our method requires significantly less pointwise classifications than previously employed algorithms.}, language = {en} } @article{GriegerSchwabedalWendeletal.2021, author = {Grieger, Niklas and Schwabedal, Justus T. C. and Wendel, Stefanie and Ritze, Yvonne and Bialonski, Stephan}, title = {Automated scoring of pre-REM sleep in mice with deep learning}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {Art. 12245}, publisher = {Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-021-91286-0}, year = {2021}, abstract = {Reliable automation of the labor-intensive manual task of scoring animal sleep can facilitate the analysis of long-term sleep studies. In recent years, deep-learning-based systems, which learn optimal features from the data, increased scoring accuracies for the classical sleep stages of Wake, REM, and Non-REM. Meanwhile, it has been recognized that the statistics of transitional stages such as pre-REM, found between Non-REM and REM, may hold additional insight into the physiology of sleep and are now under vivid investigation. We propose a classification system based on a simple neural network architecture that scores the classical stages as well as pre-REM sleep in mice. When restricted to the classical stages, the optimized network showed state-of-the-art classification performance with an out-of-sample F1 score of 0.95 in male C57BL/6J mice. When unrestricted, the network showed lower F1 scores on pre-REM (0.5) compared to the classical stages. The result is comparable to previous attempts to score transitional stages in other species such as transition sleep in rats or N1 sleep in humans. Nevertheless, we observed that the sequence of predictions including pre-REM typically transitioned from Non-REM to REM reflecting sleep dynamics observed by human scorers. Our findings provide further evidence for the difficulty of scoring transitional sleep stages, likely because such stages of sleep are under-represented in typical data sets or show large inter-scorer variability. We further provide our source code and an online platform to run predictions with our trained network.}, language = {en} } @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} } @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} } @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} } @article{HammerQuitterMayntzetal.2023, author = {Hammer, Thorben and Quitter, Julius and Mayntz, Joscha and Bauschat, J.-Michael and Dahmann, Peter and G{\"o}tten, Falk and Hille, S. and Stumpf, E.}, title = {Free fall drag estimation of small-scale multirotor unmanned aircraft systems using computational fluid dynamics and wind tunnel experiments}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-023-00702-w}, pages = {14 Seiten}, year = {2023}, abstract = {New European Union (EU) regulations for UAS operations require an operational risk analysis, which includes an estimation of the potential danger of the UAS crashing. A key parameter for the potential ground risk is the kinetic impact energy of the UAS. The kinetic energy depends on the impact velocity of the UAS and, therefore, on the aerodynamic drag and the weight during free fall. Hence, estimating the impact energy of a UAS requires an accurate drag estimation of the UAS in that state. The paper at hand presents the aerodynamic drag estimation of small-scale multirotor UAS. Multirotor UAS of various sizes and configurations were analysed with a fully unsteady Reynolds-averaged Navier-Stokes approach. These simulations included different velocities and various fuselage pitch angles of the UAS. The results were compared against force measurements performed in a subsonic wind tunnel and provided good consistency. Furthermore, the influence of the UAS`s fuselage pitch angle as well as the influence of fixed and free spinning propellers on the aerodynamic drag was analysed. Free spinning propellers may increase the drag by up to 110\%, depending on the fuselage pitch angle. Increasing the fuselage pitch angle of the UAS lowers the drag by 40\% up to 85\%, depending on the UAS. The data presented in this paper allow for increased accuracy of ground risk assessments.}, language = {en} } @article{HeelDiktaBraekers2021, author = {Heel, Mareike van and Dikta, Gerhard and Braekers, Roel}, title = {Bootstrap based goodness‑of‑fit tests for binary multivariate regression models}, series = {Journal of the Korean Statistical Society}, volume = {51}, journal = {Journal of the Korean Statistical Society}, publisher = {Springer Nature}, address = {Singapur}, issn = {2005-2863 (Online)}, doi = {10.1007/s42952-021-00142-4}, pages = {28 Seiten}, year = {2021}, abstract = {We consider a binary multivariate regression model where the conditional expectation of a binary variable given a higher-dimensional input variable belongs to a parametric family. Based on this, we introduce a model-based bootstrap (MBB) for higher-dimensional input variables. This test can be used to check whether a sequence of independent and identically distributed observations belongs to such a parametric family. The approach is based on the empirical residual process introduced by Stute (Ann Statist 25:613-641, 1997). In contrast to Stute and Zhu's approach (2002) Stute \& Zhu (Scandinavian J Statist 29:535-545, 2002), a transformation is not required. Thus, any problems associated with non-parametric regression estimation are avoided. As a result, the MBB method is much easier for users to implement. To illustrate the power of the MBB based tests, a small simulation study is performed. Compared to the approach of Stute \& Zhu (Scandinavian J Statist 29:535-545, 2002), the simulations indicate a slightly improved power of the MBB based method. Finally, both methods are applied to a real data set.}, language = {en} } @article{Heger2004, author = {Heger, Michael}, title = {Konzept hochschuldidaktischer Aktionsforschung am Beispiel INGMEDIA}, year = {2004}, abstract = {"INGMEDIA: Entwicklung und Evaluation interaktiver, multimedialer Lernsoftware f{\"u}r technische und physikalische Praktika in Ingenieurstudieng{\"a}ngen". So lautet der Titel des vom bmb+f im F{\"o}rderprogramm "Neue Medien in der Hochschullehre" unterst{\"u}tzten Verbundprojekts. [...] Im vorliegenden Beitrag wird {\"u}ber das Evaluationskonzept von INGMEDIA berichtet. Es handelt sich hierbei um einen im E-Learning-Bereich bisher kaum vertretenen Ansatz hochschuldidaktischer Aktionsforschung. Der Beitrag betont entsprechend des kevih - Tagungskonzepts (T{\"u}bingen 11./12.3.03) die besonderen hochschuldidaktischen Zielrichtungen, fokussiert also klar auf der konzeptionellen Ebene. Die Umsetzung und Evaluationsergebnisse zu INGMEDIA werden nach Projektabschluss an anderer Stelle ver{\"o}ffentlicht.}, language = {de} } @article{HegerKock2004, author = {Heger, Michael and Kock, Winfried}, title = {INGMEDIA, blended learning im Laborpraktikum. Ein hochschuldidaktisches Projekt}, year = {2004}, abstract = {Laborpraktika bieten Studierenden besondere Lernm{\"o}glichkeiten. Sie erleben im Praktikum mit Kopf (kognitiv), Herz (affektiv) und Hand (motorisch) Zusammenh{\"a}nge und Zusammenarbeit. Durch die multimediale Vorbereitung und Unterst{\"u}tzung der Laborpraktika mit INGMEDIA k{\"o}nnen diese Lernvorteile intensiver genutzt werden. Vielf{\"a}ltige und differenzierte Kontextangebote bieten individuelle Lerneinstiegsm{\"o}glichkeiten und aktivieren zu Selbstgesteuertem Lernen. Durch die Verbesserung von Vorwissen und Motivation er{\"o}ffnen scih Lehrenden und Lernenden neue Freir{\"a}ume bei der Gestaltung der Pr{\"a}senzveranstaltung. Durch hochschuldidaktische Aktionsforschung beim Einsatz im Lehrbetrieb wird die weitere Entwicklung von Software und Pr{\"a}senzveranstaltung prozesshaft begleitet.}, language = {de} } @article{HoffstadtCheenakulaNikolauszetal.2023, author = {Hoffstadt, Kevin and Cheenakula, Dheeraja and Nikolausz, Marcell and Krafft, Simone and Harms, Hauke and Kuperjans, Isabel}, title = {Design and construction of a new reactor for flexible biomethanation of hydrogen}, series = {Fermentation}, volume = {9}, journal = {Fermentation}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2311-5637}, doi = {10.3390/fermentation9080774}, pages = {1 -- 16}, year = {2023}, abstract = {The increasing share of renewable electricity in the grid drives the need for sufficient storage capacity. Especially for seasonal storage, power-to-gas can be a promising approach. Biologically produced methane from hydrogen produced from surplus electricity can be used to substitute natural gas in the existing infrastructure. Current reactor types are not or are poorly optimized for flexible methanation. Therefore, this work proposes a new reactor type with a plug flow reactor (PFR) design. Simulations in COMSOL Multiphysics ® showed promising properties for operation in laminar flow. An experiment was conducted to support the simulation results and to determine the gas fraction of the novel reactor, which was measured to be 29\%. Based on these simulations and experimental results, the reactor was constructed as a 14 m long, 50 mm diameter tube with a meandering orientation. Data processing was established, and a step experiment was performed. In addition, a kLa of 1 h-1 was determined. The results revealed that the experimental outcomes of the type of flow and gas fractions are in line with the theoretical simulation. The new design shows promising properties for flexible methanation and will be tested.}, language = {en} } @article{JablonskiMuenstermannNorketal.2021, author = {Jablonski, Melanie and M{\"u}nstermann, Felix and Nork, Jasmina and Molinnus, Denise and Muschallik, Lukas and Bongaerts, Johannes and Wagner, Torsten and Keusgen, Michael and Siegert, Petra and Sch{\"o}ning, Michael Josef}, title = {Capacitive field-effect biosensor applied for the detection of acetoin in alcoholic beverages and fermentation broths}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000765}, pages = {7 Seiten}, year = {2021}, abstract = {An acetoin biosensor based on a capacitive electrolyte-insulator-semiconductor (EIS) structure modified with the enzyme acetoin reductase, also known as butane-2,3-diol dehydrogenase (Bacillus clausii DSM 8716ᵀ), is applied for acetoin detection in beer, red wine, and fermentation broth samples for the first time. The EIS sensor consists of an Al/p-Si/SiO₂/Ta₂O₅ layer structure with immobilized acetoin reductase on top of the Ta₂O₅ transducer layer by means of crosslinking via glutaraldehyde. The unmodified and enzyme-modified sensors are electrochemically characterized by means of leakage current, capacitance-voltage, and constant capacitance methods, respectively.}, language = {en} } @article{JablonskiPoghossianKeusgenetal.2021, author = {Jablonski, Melanie and Poghossian, Arshak and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Detection of plant virus particles with a capacitive field-effect sensor}, series = {Analytical and Bioanalytical Chemistry}, volume = {413}, journal = {Analytical and Bioanalytical Chemistry}, publisher = {Springer Nature}, address = {Cham}, issn = {1618-2650}, doi = {10.1007/s00216-021-03448-8}, pages = {5669 -- 5678}, year = {2021}, abstract = {Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.}, language = {en} }