Refine
Year of publication
- 2024 (135)
- 2023 (258)
- 2022 (303)
- 2021 (293)
- 2020 (245)
- 2019 (385)
- 2018 (262)
- 2017 (262)
- 2016 (284)
- 2015 (301)
- 2014 (302)
- 2013 (301)
- 2012 (333)
- 2011 (329)
- 2010 (343)
- 2009 (369)
- 2008 (312)
- 2007 (312)
- 2006 (330)
- 2005 (303)
- 2004 (323)
- 2003 (254)
- 2002 (250)
- 2001 (221)
- 2000 (245)
- 1999 (236)
- 1998 (242)
- 1997 (220)
- 1996 (202)
- 1995 (192)
- 1994 (175)
- 1993 (155)
- 1992 (144)
- 1991 (100)
- 1990 (108)
- 1989 (111)
- 1988 (104)
- 1987 (105)
- 1986 (81)
- 1985 (84)
- 1984 (75)
- 1983 (70)
- 1982 (57)
- 1981 (54)
- 1980 (61)
- 1979 (58)
- 1978 (52)
- 1977 (32)
- 1976 (30)
- 1975 (28)
- 1974 (17)
- 1973 (12)
- 1972 (17)
- 1971 (11)
- 1970 (2)
- 1969 (2)
- 1968 (2)
- 1967 (1)
- 1963 (1)
- 1925 (1)
Institute
- Fachbereich Medizintechnik und Technomathematik (2077)
- Fachbereich Elektrotechnik und Informationstechnik (1184)
- Fachbereich Wirtschaftswissenschaften (1164)
- Fachbereich Energietechnik (1115)
- Fachbereich Chemie und Biotechnologie (914)
- Fachbereich Maschinenbau und Mechatronik (876)
- Fachbereich Luft- und Raumfahrttechnik (798)
- Fachbereich Bauingenieurwesen (711)
- IfB - Institut für Bioengineering (690)
- INB - Institut für Nano- und Biotechnologien (617)
Language
- German (5133)
- English (4929)
- Russian (14)
- Portuguese (6)
- Italian (5)
- Multiple languages (5)
- Spanish (3)
- Dutch (2)
Document Type
- Article (5658)
- Conference Proceeding (1650)
- Book (1083)
- Part of a Book (571)
- Bachelor Thesis (327)
- Patent (176)
- Report (102)
- Doctoral Thesis (80)
- Other (76)
- Administrative publication (76)
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 (23)
Zugriffsart
- campus (2151)
- weltweit (1884)
- bezahl (773)
- fachbereichsweit (FB4) (34)
The Future of Fitness : Konzeption und Gestaltung einer digitalen Fitness- und Gesundheitsanwendung
(2022)
Laut einer Langzeitstudie bewegt sich mehr als ein Viertel der Weltbevölkerung – rund 2 Milliarden Menschen – zu wenig. Trotzdem ließ sich zuletzt klares Interesse an Fitness- und Gesundheitsmöglichkeiten am stetigen Anstieg der Fitnessstudio-Mitgliederzahl erkennen. Nachdem die Zahl seit 2006 jedes Jahr anstieg, fiel sie in den Pandemie-Jahren. Seit der Pandemie besteht also Bedarf nach einer flexibleren Lösung zu klassischen Studios. Um diesen Bedarf zu decken, wurde eine digitale Lösung zum Thema entwickelt. Dazu wurden Sport und Ernährung zusammengefasst. Das beinhaltet Videoanleitungen, Ernährungs- und Trainingsplanerstellung, individuelle Körperanalyse im Onboarding-Prozess, Verbindung mit Wearables und ein flexibles Online- sowie Studioangebot. Meine Zielgruppe sind Menschen, die flexibel Sport machen, mit Sport anfangen oder ihre allgemeine Gesundheit verbessern wollen.
Soziale Netzwerke gehören zu den größten Konzernen der Welt. Hier werden minütlich Millionen von Nachrichten verschickt. Das Internet spielt eine stetig wachsende Rolle in der zwischenmenschlichen Kommunikation. Und doch funktioniert dort nicht nur die Sprache anders, auch die Persönlichkeit der Menschen kann sich auch verändern. Diese Arbeit beschäftigt sich mit dem „Online-Ich“, das jeder in sich tragen soll. Häufig ist dieses offener, hilfsbereiter und selbstloser, aber eben auch reizbarer, aggressiver und energetischer. Um auf diese Veränderung aufmerksam zu machen, werden die analoge und digitale Persönlichkeit verglichen. Dazu schöpft die Arbeit aus den vielfältigen Möglichkeiten von Virtual Reality, um Betrachtende in die Arbeit miteinzubeziehen.
In dieser Arbeit wurden kinetische Piktogramme als Kommunikationsmittel für das Stadttheater Aachen erstellt. Diese sollen als Erweiterung des bestehenden Corporate Designs ein jüngeres Publikum zu der bestehenden Zuschauerschaft hinzugewinnen. Die Piktogramme sind dabei inhaltlich an verschiedene Aufführungen des Theaters angepasst und unterstützen die Typografie in animierten Plakaten für die Außenwerbung.
Die Umsetzung der kinetischen Piktogramme wurde als Variable Font vollzogen. Damit lässt sich der Schriftschnitt durch verschiedene Interpolation-Achsen nach Belieben manipulieren. Dazu werden die Zwischenschritte automatisch errechnet, was die Technik optimal für eine 2D-Animation macht.
Anhand konkreter Anwendungsbeispiele zeigt diese Arbeit die vielen Vorteile von Variable Fonts und wirft damit einen Blick in das weite Feld ihrer spannenden Möglichkeiten, die bis dato längst noch nicht voll ausgeschöpft wurden.
Cure or blessing? The effect of (non-financial) signals on sustainable venture's funding success
(2022)
06| Warum es gemeinsam besser geht
10| Interview
14| Wer ist hier der Boss?
18| Schnittstelle zwischen Mensch und Technik
22| Zweite Heimat Jülich
28| Zwischen Angst und Hoffnung
32| Eine Sternstunde für die FH Aachen
36| Gegen alle Widerstände
38| Ein Ort, der bleibt
42| Der Aufblühende
46| Der Computer sitzt am Steuer
52| Da geht das Herz auf
54| Hoch hinaus
58| Beratungsangebote
60| Das alte Schätzchen
This thesis aims at the presentation and discussion of well-accepted and new
imaging techniques applied to different types of flow in common hydraulic
engineering environments. All studies are conducted in laboratory conditions and
focus on flow depth and velocity measurements. Investigated flows cover a wide
range of complexity, e.g. propagation of waves, dam-break flows, slightly and fully
aerated spillway flows as well as highly turbulent hydraulic jumps.
Newimagingmethods are compared to different types of sensorswhich are frequently
employed in contemporary laboratory studies. This classical instrumentation as well
as the general concept of hydraulic modeling is introduced to give an overview on
experimental methods.
Flow depths are commonly measured by means of ultrasonic sensors, also known as
acoustic displacement sensors. These sensors may provide accurate data with high
sample rates in case of simple flow conditions, e.g. low-turbulent clear water flows.
However, with increasing turbulence, higher uncertainty must be considered.
Moreover, ultrasonic sensors can provide point data only, while the relatively large
acoustic beam footprint may lead to another source of uncertainty in case of
relatively short, highly turbulent surface fluctuations (ripples) or free-surface
air-water flows. Analysis of turbulent length and time scales of surface fluctuations
from point measurements is also difficult. Imaging techniques with different
dimensionality, however, may close this gap. It is shown in this thesis that edge
detection methods (known from computer vision) may be used for two-dimensional
free-surface extraction (i.e. from images taken through transparant sidewalls in
laboratory flumes). Another opportunity in hydraulic laboratory studies comes with
the application of stereo vision. Low-cost RGB-D sensors can be used to gather
instantaneous, three-dimensional free-surface elevations, even in flows with very
high complexity (e.g. aerated hydraulic jumps). It will be shown that the uncertainty
of these methods is of similar order as for classical instruments.
Particle Image Velocimetry (PIV) is a well-accepted and widespread imaging
technique for velocity determination in laboratory conditions. In combination with
high-speed cameras, PIV can give time-resolved velocity fields in 2D/3D or even as
volumetric flow fields. PIV is based on a cross-correlation technique applied to small
subimages of seeded flows. The minimum size of these subimages defines the
maximum spatial resolution of resulting velocity fields. A derivative of PIV for
aerated flows is also available, i.e. the so-called Bubble Image Velocimetry (BIV). This
thesis emphasizes the capacities and limitations of both methods, using relatively
simple setups with halogen and LED illuminations. It will be demonstrated that
PIV/BIV images may also be processed by means of Optical Flow (OF) techniques.
OF is another method originating from the computer vision discipline, based on the
assumption of image brightness conservation within a sequence of images. The
Horn-Schunck approach, which has been first employed to hydraulic engineering
problems in the studies presented herein, yields dense velocity fields, i.e. pixelwise
velocity data. As discussed hereinafter, the accuracy of OF competes well with PIV
for clear-water flows and even improves results (compared to BIV) for aerated flow
conditions. In order to independently benchmark the OF approach, synthetic images
with defined turbulence intensitiy are used.
Computer vision offers new opportunities that may help to improve the
understanding of fluid mechanics and fluid-structure interactions in laboratory
investigations. In prototype environments, it can be employed for obstacle detection
(e.g. identification of potential fish migration corridors) and recognition (e.g. fish
species for monitoring in a fishway) or surface reconstruction (e.g. inspection of
hydraulic structures). It can thus be expected that applications to hydraulic
engineering problems will develop rapidly in near future. Current methods have not
been developed for fluids in motion. Systematic future developments are needed to
improve the results in such difficult conditions.
High aerodynamic efficiency requires propellers with high aspect ratios, while propeller sweep potentially reduces noise. Propeller sweep and high aspect ratios increase elasticity and coupling of structural mechanics and aerodynamics, affecting the propeller performance and noise. Therefore, this paper analyzes the influence of elasticity on forward-swept, backward-swept, and unswept propellers in hover conditions. A reduced-order blade element momentum approach is coupled with a one-dimensional Timoshenko beam theory and Farassat's formulation 1A. The results of the aeroelastic simulation are used as input for the aeroacoustic calculation. The analysis shows that elasticity influences noise radiation because thickness and loading noise respond differently to deformations. In the case of the backward-swept propeller, the location of the maximum sound pressure level shifts forward by 0.5 °, while in the case of the forward-swept propeller, it shifts backward by 0.5 °. Therefore, aeroacoustic optimization requires the consideration of propeller deformation.
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.
Even the shortest flight through unknown, cluttered environments requires reliable local path planning algorithms to avoid unforeseen obstacles. The algorithm must evaluate alternative flight paths and identify the best path if an obstacle blocks its way. Commonly, weighted sums are used here. This work shows that weighted Chebyshev distances and factorial achievement scalarising functions are suitable alternatives to weighted sums if combined with the 3DVFH* local path planning algorithm. Both methods considerably reduce the failure probability of simulated flights in various environments. The standard 3DVFH* uses a weighted sum and has a failure probability of 50% in the test environments. A factorial achievement scalarising function, which minimises the worst combination of two out of four objective functions, reaches a failure probability of 26%; A weighted Chebyshev distance, which optimises the worst objective, has a failure probability of 30%. These results show promise for further enhancements and to support broader applicability.
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.