Refine
Year of publication
Document Type
- Article (5586)
- Conference Proceeding (1620)
- Book (1078)
- Part of a Book (548)
- Bachelor Thesis (297)
- Patent (172)
- Report (100)
- Doctoral Thesis (78)
- Other (77)
- Administrative publication (76)
- Part of Periodical (63)
- Lecture (30)
- Master's Thesis (20)
- Contribution to a Periodical (19)
- Review (17)
- Diploma Thesis (15)
- Working Paper (13)
- Course Material (9)
- Talk (7)
- Study Thesis (5)
- Habilitation (4)
- Poster (4)
- Preprint (4)
- Examination Thesis (1)
- Video (1)
Language
- German (5012)
- English (4801)
- Russian (14)
- Portuguese (6)
- Multiple languages (5)
- Spanish (3)
- nld (2)
- Italien (1)
Keywords
- Amtliche Mitteilung (71)
- Bachelor (33)
- Aachen University of Applied Sciences (31)
- Master (31)
- Prüfungsordnung (31)
- Bauingenieurwesen (30)
- Lesbare Fassung (28)
- Biosensor (25)
- Fachhochschule Aachen (23)
- Illustration (21)
- Studien- und Prüfungsordnung (21)
- Aachen / Fachhochschule Aachen (20)
- Änderungsordnung (20)
- Blitzschutz (18)
- Corporate Design (17)
- Elektromobilität (17)
- CAD (16)
- Finite-Elemente-Methode (16)
- Fotografie (16)
- civil engineering (14)
Institute
- Fachbereich Medizintechnik und Technomathematik (2052)
- Fachbereich Elektrotechnik und Informationstechnik (1150)
- Fachbereich Wirtschaftswissenschaften (1138)
- Fachbereich Energietechnik (1104)
- Fachbereich Maschinenbau und Mechatronik (866)
- Fachbereich Chemie und Biotechnologie (847)
- Fachbereich Luft- und Raumfahrttechnik (776)
- Fachbereich Bauingenieurwesen (705)
- IfB - Institut für Bioengineering (686)
- INB - Institut für Nano- und Biotechnologien (613)
- Fachbereich Gestaltung (484)
- Solar-Institut Jülich (339)
- Fachbereich Architektur (174)
- FH Aachen (153)
- ECSM European Center for Sustainable Mobility (112)
- ZHQ - Bereich Hochschuldidaktik und Evaluation (74)
- MASKOR Institut für Mobile Autonome Systeme und Kognitive Robotik (71)
- Nowum-Energy (70)
- Institut fuer Angewandte Polymerchemie (32)
- Sonstiges (24)
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.
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.
Using scenarios is vital in identifying and specifying measures for successfully transforming the energy system. Such transformations can be particularly challenging and require the support of a broader set of stakeholders. Otherwise, there will be opposition in the form of reluctance to adopt the necessary technologies. Usually, processes for considering stakeholders' perspectives are very time-consuming and costly. In particular, there are uncertainties about how to deal with modifications in the scenarios. In principle, new consulting processes will be required. In our study, we show how multi-criteria decision analysis can be used to analyze stakeholders' attitudes toward transition paths. Since stakeholders differ regarding their preferences and time horizons, we employ a multi-criteria decision analysis approach to identify which stakeholders will support or oppose a transition path. We provide a flexible template for analyzing stakeholder preferences toward transition paths. This flexibility comes from the fact that our multi-criteria decision aid-based approach does not involve intensive empirical work with stakeholders. Instead, it involves subjecting assumptions to robustness analysis, which can help identify options to influence stakeholders' attitudes toward transitions.
The connective tissues such as tendons contain an extracellular matrix (ECM) comprising collagen fibrils scattered within the ground substance. These fibrils are instrumental in lending mechanical stability to tissues. Unfortunately, our understanding of how collagen fibrils reinforce the ECM remains limited, with no direct experimental evidence substantiating current theories. Earlier theoretical studies on collagen fibril reinforcement in the ECM have relied predominantly on the assumption of uniform cylindrical fibers, which is inadequate for modelling collagen fibrils, which possessed tapered ends. Recently, Topçu and colleagues published a paper in the International Journal of Solids and Structures, presenting a generalized shear-lag theory for the transfer of elastic stress between the matrix and fibers with tapered ends. This paper is a positive step towards comprehending the mechanics of the ECM and makes a valuable contribution to formulating a complete theory of collagen fibril reinforcement in the ECM.
To fulfil the CO2 emission reduction targets of the European Union (EU), heavy-duty (HD) trucks need to operate 15% more efficiently by 2025 and 30% by 2030. Their electrification is necessary as conventional HD trucks are already optimized for the long-haul application. The resulting hybrid electric vehicle (HEV) truck gains most of the fuel saving potential by the recuperation of potential energy and its consecutive utilization. The key to utilizing the full potential of HEV-HD trucks is to maximize the amount of recuperated energy and ensure its intelligent usage while keeping the operating point of the internal combustion engine as efficient as possible. To achieve this goal, an intelligent energy management strategy (EMS) based on ECMS is developed for a parallel HEV-HD truck which uses predictive discharge of the battery and adaptive operating strategy regarding the height profile and the vehicle mass. The presented EMS can reproduce the global optimal operating strategy over long phases and lead to a fuel saving potential of up to 2% compared with a heuristic strategy. Furthermore, the fuel saving potential is correlated with the investigated boundary conditions to deepen the understanding of the impact of intelligent EMS for HEV-HD trucks.
Messenger apps like WhatsApp and Telegram are frequently used for everyday communication, but they can also be utilized as a platform for illegal activity. Telegram allows public groups with up to 200.000 participants. Criminals use these public groups for trading illegal commodities and services, which becomes a concern for law enforcement agencies, who manually monitor suspicious activity in these chat rooms. This research demonstrates how natural language processing (NLP) can assist in analyzing these chat rooms, providing an explorative overview of the domain and facilitating purposeful analyses of user behavior. We provide a publicly available corpus of annotated text messages with entities and relations from four self-proclaimed black market chat rooms. Our pipeline approach aggregates the extracted product attributes from user messages to profiles and uses these with their sold products as features for clustering. The extracted structured information is the foundation for further data exploration, such as identifying the top vendors or fine-granular price analyses. Our evaluation shows that pretrained word vectors perform better for unsupervised clustering than state-of-the-art transformer models, while the latter is still superior for sequence labeling.
It has been shown that muscle fascicle curvature increases with increasing contraction level and decreasing muscle–tendon complex length. The analyses were done with limited examination windows concerning contraction level, muscle–tendon complex length, and/or intramuscular position of ultrasound imaging. With this study we aimed to investigate the correlation between fascicle arching and contraction, muscle–tendon complex length and their associated architectural parameters in gastrocnemius muscles to develop hypotheses concerning the fundamental mechanism of fascicle curving. Twelve participants were tested in five different positions (90°/105°*, 90°/90°*, 135°/90°*, 170°/90°*, and 170°/75°*; *knee/ankle angle). They performed isometric contractions at four different contraction levels (5%, 25%, 50%, and 75% of maximum voluntary contraction) in each position. Panoramic ultrasound images of gastrocnemius muscles were collected at rest and during constant contraction. Aponeuroses and fascicles were tracked in all ultrasound images and the parameters fascicle curvature, muscle–tendon complex strain, contraction level, pennation angle, fascicle length, fascicle strain, intramuscular position, sex and age group were analyzed by linear mixed effect models. Mean fascicle curvature of the medial gastrocnemius increased with contraction level (+5 m−1 from 0% to 100%; p = 0.006). Muscle–tendon complex length had no significant impact on mean fascicle curvature. Mean pennation angle (2.2 m−1 per 10°; p < 0.001), inverse mean fascicle length (20 m−1 per cm−1; p = 0.003), and mean fascicle strain (−0.07 m−1 per +10%; p = 0.004) correlated with mean fascicle curvature. Evidence has also been found for intermuscular, intramuscular, and sex-specific intramuscular differences of fascicle curving. Pennation angle and the inverse fascicle length show the highest predictive capacities for fascicle curving. Due to the strong correlations between pennation angle and fascicle curvature and the intramuscular pattern of curving we suggest for future studies to examine correlations between fascicle curvature and intramuscular fluid pressure.
Herein, fibroin, polylactide (PLA), and carbon are investigated for their suitability as biocompatible and biodegradable materials for amperometric biosensors. For this purpose, screen-printed carbon electrodes on the biodegradable substrates fibroin and PLA are modified with a glucose oxidase membrane and then encapsulated with the biocompatible material Ecoflex. The influence of different curing parameters of the carbon electrodes on the resulting biosensor characteristics is studied. The morphology of the electrodes is investigated by scanning electron microscopy, and the biosensor performance is examined by amperometric measurements of glucose (0.5–10 mM) in phosphate buffer solution, pH 7.4, at an applied potential of 1.2 V versus a Ag/AgCl reference electrode. Instead of Ecoflex, fibroin, PLA, and wound adhesive are tested as alternative encapsulation compounds: a series of swelling tests with different fibroin compositions, PLA, and Ecoflex has been performed before characterizing the most promising candidates by chronoamperometry. Therefore, the carbon electrodes are completely covered with the particular encapsulation material. Chronoamperometric measurements with H2O2 concentrations between 0.5 and 10 mM enable studying the leakage current behavior.
Wohlfühlen in den eigenen vier Wänden : ein Produkt, welches die Wohn- und Lebensqualität steigert.
(2023)
Viele Menschen fühlen sich in ihren eigenen vier Wänden nicht wohl. Sie sind gestresst und können nicht entspannen. Ziel dieser Arbeit ist es, ein Produkt zu erschaffen, welches in seinen Funktionen und seinem Design dafür sorgt, dass die Nutzer:innen sich zu Hause wohler fühlen. Es soll alle Funktionen vereinen, die dafür sorgen, dass der Alltagsstress besser bewältigt werden kann und man in seinem Zuhause entspannen kann und den Moment mehr genießt. Entstanden ist Iwa, ein Produkt, welches zum einen als Luftreiniger arbeitet und die Raumluft filtert und im Zusammenspiel mit Licht und Musik die Raumatmosphäre verbessert und so Stress mindert. Das Design soll genau wie die Funktionen beruhigend, entspannend und erdend wirken. Es ist angelehnt am Zen-Design. So bietet Iwa einen großen Mehrwert. Die Funktionen sorgen im Zusammenspiel mit dem Design für eine verbesserte Wohn- und Lebensqualität.
Essen zuzubereiten bedeutet für viele Menschen Normalität, es bestimmt Teile ihrer Identität und ist eng verbunden mit Familie und Kultur. Der Beginn der Alzheimererkrankung erschwert diese Tätigkeit, oft muss sie aus Sicherheitsgründen aufgegeben werden. Kochen als Therapieansatz hat zur Verbesserung der Aktivität und Verringerung von Stress beigetragen. Pila ist ein Küchensystem, das Kochenthusiasten begleitet und Selbstständigkeit sowie Partizipation ermöglicht. Das Kompetenzgefühl, die Autonomie und die Verbundenheit zu betreuenden Personen stärken das Wohlbefinden. Das System führt die Nutzerinnen und Nutzer digital durch alle Phasen von der Vorbereitung bis zum Aufräumen. Aus den Elementen entsteht ein klar organisierter Arbeitsplatz ohne Ablenkungen und mit eindeutigen Aktionspunkten. Die Funktionen der Kocheinheit sind simplifiziert und bedürfnisgerecht angepasst.
Jedes Jahr werden Hunderttausende Fahrradrahmen produziert. 90 % davon werden in Asien hergestellt und von dort über die ganze Welt versendet. Mehr als 80 % der Rahmen werden nach der Nutzung wieder nach Asien zurückgeschickt und landen dort auf riesigen Fahrradfriedhöfen. Das Kinderfahrradkonzept "KiBix" wirkt diesem Problem entgegen, indem es eine Alternative für das regelmäßige Kaufen von neuen Kinderfahrrädern bietet. Im Fokus stehen der Kinderfahrradrahmen und die Gabel aus Kunststoff, welche im Spritzgussverfahren produziert werden. Das City-Bike ist in ein Abo-Sharing-System mit Rädern in unterschiedlichen Größen eingebettet, welches durch eine monatliche Gebühr wie das Eigene genutzt werden kann. Der hohlgespritzte Rahmen ermöglicht die Integration kleiner Boxen im Inneren, in denen Kinder ihre persönlichen "Schätze" mitnehmen können. Somit vereint das Konzept die drei Segmente Material/Produktion, Sharing-System und die Mitnahme des "Schatzes". "KiBix" gibt Kindern in Zeiten der Digitalisierung und der globalen Erwärmung die Möglichkeit, selbstbestimmt und nachhaltig die Welt zu erkunden.
Background
Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians.
Methods
In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204).
Measurements and main results
PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42% ± 1.77% vs. 4.64% ± 2.59%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5–190.2] vs. 189.1 [179.4–197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8–0.9] vs. 0.88 [0.8–0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = − 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters.
Conclusion
Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.
Deammonification for nitrogen removal in municipal wastewater in temperate and cold climate zones is currently limited to the side stream of municipal wastewater treatment plants (MWWTP). This study developed a conceptual model of a mainstream deammonification plant, designed for 30,000 P.E., considering possible solutions corresponding to the challenging mainstream conditions in Germany. In addition, the energy-saving potential, nitrogen elimination performance and construction-related costs of mainstream deammonification were compared to a conventional plant model, having a single-stage activated sludge process with upstream denitrification. The results revealed that an additional treatment step by combining chemical precipitation and ultra-fine screening is advantageous prior the mainstream deammonification. Hereby chemical oxygen demand (COD) can be reduced by 80% so that the COD:N ratio can be reduced from 12 to 2.5. Laboratory experiments testing mainstream conditions of temperature (8–20°C), pH (6–9) and COD:N ratio (1–6) showed an achievable volumetric nitrogen removal rate (VNRR) of at least 50 gN/(m3∙d) for various deammonifying sludges from side stream deammonification systems in the state of North Rhine-Westphalia, Germany, where m3 denotes reactor volume. Assuming a retained Norganic content of 0.0035 kgNorg./(P.E.∙d) from the daily loads of N at carbon removal stage and a VNRR of 50 gN/(m3∙d) under mainstream conditions, a resident-specific reactor volume of 0.115 m3/(P.E.) is required for mainstream deammonification. This is in the same order of magnitude as the conventional activated sludge process, i.e., 0.173 m3/(P.E.) for an MWWTP of size class of 4. The conventional plant model yielded a total specific electricity demand of 35 kWh/(P.E.∙a) for the operation of the whole MWWTP and an energy recovery potential of 15.8 kWh/(P.E.∙a) through anaerobic digestion. In contrast, the developed mainstream deammonification model plant would require only a 21.5 kWh/(P.E.∙a) energy demand and result in 24 kWh/(P.E.∙a) energy recovery potential, enabling the mainstream deammonification model plant to be self-sufficient. The retrofitting costs for the implementation of mainstream deammonification in existing conventional MWWTPs are nearly negligible as the existing units like activated sludge reactors, aerators and monitoring technology are reusable. However, the mainstream deammonification must meet the performance requirement of VNRR of about 50 gN/(m3∙d) in this case.
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.
Die Auswahl der passenden Geschäftsprozesse für eine Automatisierung mittels Robotic Process Automation (RPA) ist für den Erfolg von RPA-Projekten entscheidend. Das vorliegende Kapitel liefert dafür Selektionskriterien, die aus einer qualitativen Studie mit elf interviewten RPA-Experten aus dem Versicherungsumfeld resultieren. Das Ergebnis umfasst eine gewichtete Liste von sieben Dimensionen und 51 Prozesskriterien, welche die Automatisierung mit Softwarerobotern begünstigen beziehungsweise deren Nichterfüllung eine Umsetzung erschweren oder sogar verhindern. Die drei wichtigsten Kriterien zur Auswahl von Geschäftsprozessen für die Automatisierung mittels RPA umfassen die Entlastung der an dem Prozess mitwirkenden Mitarbeiter (Arbeitnehmerentlastung), die Ausführbarkeit des Prozesses mittels Regeln (Regelbasierte Prozessteuerung) sowie ein positiver Kosten-Nutzen-Vergleich. Auf diesen Ergebnissen aufbauend wird ein Vergleich mit den bereits bekannten Selektionskriterien aus der Literatur erstellt und diskutiert. Praktiker können die Ergebnisse verwenden, um eine systematische Auswahl von RPA-relevanten Prozessen vorzunehmen. Aus wissenschaftlicher Perspektive stellen die Ergebnisse eine Grundlage zur Erklärung des Erfolgs und Misserfolgs von RPA-Projekten dar.
Krebstherapie bei Kindern ist für alle Beteiligten eine emotional bedrückende Angelegenheit. Besonders die Strahlentherapie stellt Kinder aufgrund der Häufigkeit der Termine, der Isolation während der Bestrahlung und der Fixierung vor Herausforderungen. „nia“ ermöglicht es den Angehörigen, während der Behandlung einen physischen Kontakt zum Kind zu halten. Zwei miteinander verbundene Zwillingsgeräte registrieren die Bewegungen der Hände und übertragen die Berührung an das jeweils andere Gerät. Diese taktile Kommunikation sorgt für innere Ruhe und Verbundenheit. Vor der eigentlichen Therapie liegen die Geräte in einem Koffer, welcher ein Modell des Behandlungsraums beinhaltet. Mithilfe dessen werden die Kinder spielerisch auf die Bestrahlung vorbereitet. So sollen sich in Zukunft weniger Kinder ängstlich und allein einer Strahlentherapie stellen müssen.
Inhaltsverzeichnis - Bachelorarbeiten
1. Zukunft der Rente – Kann eine Erwerbstätigenversicherung das
demografische Problem nachhaltig lösen?
- Marcel Sept | Seite 4-73
2. Die versammlungsgebundenen Aktionärsrechte in der neuen
virtuellen Hauptversammlung – eine Bewertung aus Unternehmer- und Aktionärssicht
- Christina Zillinger | Seite 74-130
3. Praxisleitfaden für den Arbeitgeber zum gesetzlichen
Sonderkündigungsschutz – Was muss der Arbeitgeber tun, um durch
Gesetz besonders geschützten Arbeitnehmern kündigen zu können?
- Johanna Wiechert | Seite 131-195
4. Die Steuervergünstigung bei Umstrukturierungen im Konzern nach
§ 6a GrEStG im Lichte der aktuellen Rechtsprechung
- Marius Thelen | Seite 196-265