398 research outputs found
Software for calibrating a digital image processing
This work is about learning tool wich provides the necessary parameters for a program controlling robots of type LUKAS at the Faculty of Mechanical Engineering. The robot controlling program needs various parameters depending on its environment, like the light intensity distribution, and camera settings as exposure time and gain raw. These values have to be transmitted from the learning tool to the robot controlling software. Chapter one introduces the robots of type LUKAS which are created for the RoboCup Small Size League. Furthermore, it introduces the camera used for image processing.
The second chapter explains the learning process according to Christoph UBfeller and deduces the requirements for this work.
In the third chapter theoretical basics concerning image processing, wich are fundamental for this work, are explained.
Chapter 4 describes the developed learning tool which is used for the learning process and generates the required parameters for the robot controlling software.
In chapter five practical test with two persons are represented.
The sixth and last chapter summarizes the results.Tesi
Influence of heating rate on the solid yield of biomass pyrolysis
The use of biochar has become increasingly popular over the last decade. The possible applications are vast and range from renewable carbon carrier in industrial and energetic applications to soil amendment and fodder additive. The various applications have different demands on the properties of biochar. These can be influenced by the choice of feedstock, reactor and production conditions. Regardless of production process and application however, achieving a high yield of the solid product is desirable from an economic point of view. The higher the treatment temperature, the more material is devolatilized and the lower is the amount of biochar that remains after pyrolysis [1]. Nevertheless, some properties such as a very high relative carbon content can only be achieved at high temperatures and therefore at the cost of the char yield. Furthermore, it is generally accepted that a higher heating rate leads to a lower char yield and vice versa. Despite this common believe, there is not a large amount of systematic data available, which shows these correlations. Investigations using rapeseed straw as an example show that the heating rate of up to about 5 K/min initially increases the char yield [2]. As the heating rate continues to rise, the mass yield of biochar decreases. Similar results have already been observed in [3] and [4]. Nevertheless, systematic studies that would allow quantifying the influence of the heating rate on the solid char yield have not been conducted. This study aims to fill this gap.
Using systematic experiments with a thermogravimetric analyzer (TGA), the effects of the heating rate on the solid yield of biomass during slow pyrolysis are investigated. Biomass is a very inhomogeneous feedstock and the influence of the various components not clearly distinguishable from each other. Furthermore, reproducibility is poor, especially given the small amounts typically used in thermogravimetric analyses. Therefore, the experiments are carried out using not only wood as a feedstock, but also pure cellulose and lignin. The latter is often associated with a higher achievable char yield.
During the investigations, the starting materials are pyrolyzed in an inert atmosphere and at different heating rates, all within the regime of slow pyrolysis. The heat treatment temperature is varied between 450 and 700 °C, corresponding to typical conditions in practical biochar production processes. A sufficient holding time helps to minimize the effect of different carbonization degrees on the measurable char yield. Combining the different feedstocks with the pyrolysis conditions creates a broad data basis. This aids the quantification of the change in solid yield that can be achieved by varying the heating rate. After the experiments in the TGA, the resulting biochar is examined under the microscope for optical differences in pore structure and size in order to gain further insights into the influence of the heating rate. The results will further improve the understanding of biomass pyrolysis and optimize the process parameters for biochar production.
[1]
Weber, K.; Quicker, P.: Properties of biochar. In: Fuel. 217, 2018, pp 240-261
[2]
Zhao, B. et al.: Effect of pyrolysis temperature, heating rate, and residence time on rapeseed stem derived biochar. In: Journal of Cleaner Production. 174, 2018, pp 977-987
[3]
Karaosmanoglu, F.; IsigigĂŒr-ErgĂŒdenler, A.; Sever, A.: Biochar from the Straw-Stalk of Rapeseed Plant. In: Energy & Fuels. 14, 2000, pp 336-339,
[4]
Mermoud, F. et al.: Influence of the pyrolysis heating rate on the steam gasification rate of large wood char particles. In: Fuel. 85, 2006, pp 1473-148
Activity of FGF-2 in comparison to the FGF-s3-His Fragment on Human Adipose Derived Stem Cells
Humane Fettstammzellen sind adulte, mesenchymale Stammzellen. Prinzipiell sind in den meisten Geweben Zellen mit Stammzelleigenschaften zu finden, die dort Aufgaben in Bezug auf Geweberegeneration (z.B.: Knochenmark, Darm) erfĂŒllen. Humane Fettstammzellen sind zum einen leicht zugĂ€nglich (z.B. plastische Chirurgie, Abfallprodukt bei Liposuktion) und haben zum anderen die FĂ€higkeit in verschiedene Gewebe zu differenzieren. Somit rĂŒckten sie, vor allem im Zusammenhang mit zellbasierten Therapien im Bereich der regenerativen Medizin und Geweberekonstruktion, immer mehr in den Fokus der biomedizinischen Forschung. FĂŒr den möglichen, routinemĂ€Ăigen und klinischen Einsatz von humanen Fettstammzellen ist es wichtig, das Wissen der zugrunde liegenden molekularen Mechanismen und physiologischen ZusammenhĂ€nge von Wachstum und Differenzierung zu untersuchen.
Humaner Fibroblasten Wachstumsfaktor (hFGF-2) ist ein wichtiger Wachstumsfaktor durch den unter anderem VorgÀnge wie Zellwachstum und -differenzierung, Gewebereparatur und regeneration (Knorpel-, Nervengewebe) sowie Angiogenese induziert beziehungsweise gesteuert werden können. In diesem Zusammenhang ist seine Rolle vor allem in der Embryonalentwicklung, aber auch in adulten Geweben tragend. Die FGF-Familie stellt eine Gruppe von Signalproteinen dar, die spezifische Rezeptor-Tyrosin Kinasen an ZelloberflÀchen binden (FGF-Rezeptoren, FGFR) und durch eine Signaltransduktionskaskade ins Zellinnere FGF Zielgene aktivieren. Humaner FGF-2 beeinflusst somit die Zellphysiologie und kann als in vitro Zellstimulans verwendet werden.
Ziel des Projekts war es, die Auswirkungen von rekombinantem hFGF-2 auf die in vitro Proliferation bzw. Differenzierung von adulten Stammzellen (humanen Fettstammzellen) zu untersuchen. Es wurden zwei verschiedene hFGF-2 Konzentrationen, niedrig (3 ng/mL) und hoch (30 ng/mL), eingesetzt und die stimulierten Zellen folglich 28 Tage lang beobachtet. Weiters wurde die AktivitÀt von den 2 eigens produzierten und aufgereinigten FGF-(Teil)peptiden FGF-2 HIS und FGF-s3 HIS untersucht und mit dem kommerziell erhÀltlichen, rekombinanten hFGF-2 (rhFGF-2) verglichen.
Die Ergebnisse zeigten eine nur schwache biologische AktivitĂ€t des FGF-s3 HIS Fragments im Vergleich zu rhFGF-2 und FGF-2 HIS. FGF-s3 HIS bindet mit hoher AffinitĂ€t an Fibrin/Fibrinogen, und könnte somit in Zukunft als Bindungspartner zwischen Fibrin und anderen Zielsubstanzen (z.B. Medikamente) fĂŒr therapeutische Zwecke eingesetzt werden.
Im Gegensatz dazu, förderten FGF-2 HIS und rhFGF-2 das Zellwachstum und die die Expression von Proteinen der extrazellulĂ€ren Matrix. Alle drei Punkte sind essentiell fĂŒr die Gewebekonstruktion (Tissue Engineering) von Knochen, Sehnen und BĂ€ndern. Zwei Phasen der Zellantwort waren zu beobachten, ein Anstieg des Zellwachstums und der Proliferationsraten zwischen Tag 14 und 21, beziehungsweise die Erhöhung der Expression von Kollagen Type 1, Kollagen Type 3 und Vimentin ab Tag 21. Histologisch Ă€uĂerte sich die hFGF-2 Behandlung in einer fibroblastischen, homogen wirkenden Zellmorphologie. Unterschiede zwischen 3 ng/mL und 30 ng/mL hFGF-2 Behandlungen wurden vor allem in der FGF-2 HIS Gruppe deutlich. Obwohl 30 ng/mL hFGF-2 höhere Zellzahlen und biologische AktivitĂ€t hervorbrachte, vermuten wir, dass sich eine Dosis von 3 ng/mL hFGF-2 besser auf die osteogene Differenzierung auswirkt. Diese Hypothese muss allerdings noch durch genauere Methoden, wie quantitative Real time PCR, die Bestimmung der alkalischen Phosphatase (ALP) bzw. durch den Nachweis mineralisierter Matrix verifiziert werden. Die Peptide rhFGF-2 und FGF-2 HIS mĂŒssen in Hinsicht der eingesetzten Konzentrationen gesondert betrachtet werden und rhFGF-2 sollte in einer noch geringeren Konzentration von 1 ng/mL getestet werden. Jedenfalls wurde die Vermutung bestĂ€tigt, dass meschenchymale Stammzellen aus humanem Fettgewebe beziehungsweise aus dem Knochenmark, unterschiedlich sensibel auf verschiedene hFGF-2 Konzentrationen reagieren.Human adipose derived stem (hASCs) cells, are adult stem cells originated from mesenchyme. Somatic stem cells are present in many tissues and organs of the body, rendering important function in tissue regeneration. Due to the ability of hASCs, to give rise to various mature cell types/tissues and the easy isolation procedure, they have been proposed as potential candidates for cell based therapies in the fields of regenerative medicine and tissue engineering.
Human fibroblast growth factor 2 (hFGF-2) is an important growth factor, which regulates, among, others cell growth, -differentiation, -proliferation and angiogenesis. Human FGF-2 is essential during early embryonic development but also throughout life in the regeneration of adult tissues. The FGF family constitutes a group of related polypeptides, which are able, upon binding to specific transmembrane receptor tyrosine kinases (FGFR), to activate signal pathways, which are associated with cell growth, migration and proliferation. Human FGF-2 is produced by various cell types in vivo and can be used as culture additive in vitro.
The aim of the project was, to examine the in vitro effects of different hFGF-2 doses (3 ng/mL and 30 ng/mL) on human adipose derived stem cells. Apart from commercially available recombinant hFGF-2 (rhFGF-2), additionally the biological activities of two self-produced FGF-2 constructs (FGF-2 HIS, FGF-s3 HIS) were analyzed over 28 days, regarding cell growth, morphology, viability, apoptosis rates, proliferation status and differentiation.
The results revealed only weak biological effects on cell proliferation, -growth and -viability, of the truncated FGF-s3 HIS fragment. As FGF-s3 HIS binds with high affinity to fibrin/fibrinogen, the fragment could be used as a linking partner between fibrin and drugs, rendering therapeutic issues.
FGF-2 HIS and rhFGF-2 both increased cell growth and the expression of extracellular matrix proteins (e.g. collagen type 1, collagen type 3, vimentin and desmin), which are essential hallmarks in engineering of bone, tendons and ligaments. Cells reacted to hFGF-2 treatment in a characteristic, biphasic respond, with an initial phase of enhanced cell growth. The second phase was marked by an increase of collagen type 1, collagen type 3 and vimentin mRNA expression. Morphologically, cells displayed a fibroblast like, homogenous looking cell morphology. Differences between low (3 ng/mL) and high (30 ng/mL) dose hFGF-2 treatment were most distinct in the FGF-2 HIS group. Highest cell numbers were obtained with 30 ng/mL rhFGF-2. Nevertheless, we suggest that low dose hFGF-2 is more suited for osteogenic differentiation. However, this hypothesis still remains to be investigated in more detail, probably by means of quantitative Real time PCR and using osteogenic medium. We conclude that both, FGF-2 HIS and rhFGF-2, are biological active, but they have to be regarded separately concerning the administered dosage
Network Simulation for Pedestrian Flows with HyDEFS
The reliable simulation of pedestrian movement is an essential tool for the security aware design and analysis of buildings and infrastructure. We developed HyDEFS, an event-driven dynamic flow simulation software which is designed to simulate pedestrian movement depending on varying routing decisions of the individual users and varying constraints. HyDEFS uses given density depending velocities to model congestions and evaluates flow distributions with respect to average and maximum travel time. This is of particular importance when considering evacuation scenarios. We apply HyDEFS on two small networks and cross validate its results by time-discrete and time-continuous calculations
Kinder mit geistiger Behinderung in Pflegefamilien: eine explorative Studie aus der Perspektive von Pflegeeltern
Die vorliegende Arbeit analysiert die Situation von Pflegekindern mit geistiger
Behinderung in Pflegefamilien aus der Perspektive von Pflegeeltern. Die
besonderen Erfahrungen eines Pflegekindes und die Motivation der Pflegeeltern
treffen beim Ăbergang von der Herkunftsfamilie in die Pflegefamilie aufeinander.
Das Erleben der Pflegeeltern, in der Phase des Ăbergangs und noch Jahre danach
stehen dabei im Mittelpunkt. Eine explizite Betrachtung von Pflegefamilien, die ein
Kind mit geistiger Behinderung im Rahmen der Vollzeitpflege in die Familie
aufgenommen haben, wurde bisher wenig in den Blickpunkt gerĂŒckt. Diese Arbeit
soll Einblicke in die Thematik geben. In einer empirischen Untersuchung wurden
Aspekte von Motivation, Elternschaft, Bedeutung von Behinderung und Bindung
im Kontext der Aufnahme eines Pflegekindes mit geistiger Behinderung
untersucht. Zur Bearbeitung der Forschungsfragen wurde ein exploratives
Forschungsdesign gewÀhlt. Mithilfe qualitativer Leitfadeninterviews wurden
Pflegeeltern befragt. Die Auswertung der gewonnenen qualitativen Daten
geschieht durch eine qualitative Inhaltsanalyse, insbesondere durch eine
zusammenfassende Inhaltsanalyse nach Mayring. Die Studie versteht sich als eine
explorative Studie zur Hypothesengenerierung und fĂŒr weitere empirische
Untersuchungen
Optimal control for port-Hamiltonian systems and a new perspective on dynamic network flow problems
We formulate open-loop optimal control problems for general port-Hamiltonian
systems with possibly state-dependent system matrices and prove their
well-posedness. The optimal controls are characterized by the first-order
optimality system, which is the starting point for the derivation of an
adjoint-based gradient descent algorithm. Moreover, we discuss the relationship
of port-Hamiltonian dynamics and minimum cost network flow problems. Our
analysis is underpinned by a proof of concept, where we apply the proposed
algorithm to static minimum cost flow problems and dynamic minimum cost flow
problems with a simple directed acyclic graph. The numerical results validate
the approach
Closure times of neurocranial sutures and synchondroses in Persian compared to Domestic Shorthair cats
Human-directed selective breeding has modified the phenotype of the modern Persian cat towards an extreme brachycephalic phenotype (âpeke-faceâ Persian), which originates from a spontaneous mutation that first appeared in the 1950s in traditional Persian types. It was suggested that the peke-face phenotype results from pathologic skull development and might represent a craniosynostosis of the coronal sutures. We followed this hypothesis and investigated the time dependent status of the neurocranial sutures and synchondroses in an ontogenetic series of doll-faced and peke-faced Persian cats compared to Domestic Shorthair cats (DSHs). Cranial suture closure was assessed by examining an ontogenetic series of formalin-fixed head specimens (nâ=â55) and dry skulls (nâ=â32) using micro-computed tomography. Sagittal, metopic, coronal and lambdoid sutures as well as intersphenoidal, spheno-occipital and spheno-ethmoid synchondroses were examined. Logistic regression analysis was performed to test the global effect of age on suture closure within a group of peke-face Persians, doll-face Persians and DSHs and the 50% probability of having a closed suture was calculated and compared between groups. Age was a perfect predictor for the condition of the coronal sutures in peke-face Persians. Coronal sutures were found to be closed at 0â0.3 months. In doll-face and DSHs, coronal sutures were open throughout the lifetime with the exception of a few very old cats. Results of this study confirmed a coronal craniosynostosis that likely causes the extreme brachycephalic skull morphology in the peke-face Persian
Accurate typing of Human Leukocyte Antigen class I genes by Oxford nanopore sequencing
Oxford Nanopore Technologiesâ MinION has expanded the current DNA sequencing toolkit by delivering long read lengths and extreme portability. The MinION has the potential to enable expedited point-of-care human leukocyte antigen (HLA) typing, an assay routinely used to assess the immunological compatibility between organ donors and recipients, but the platformâs high error rate makes it challenging to type alleles with accuracy. Here, we developed and validated accurate typing of HLA by Oxford nanopore (Athlon), a bioinformatic pipeline that i) maps nanopore reads to a database of known HLA alleles, ii) identifies candidate alleles with the highest read coverage at different resolution levels that are represented as branching nodes and leaves of a tree structure, iii) generates consensus sequences by remapping the reads to the candidate alleles, and iv) calls the final diploid genotype by blasting consensus sequences against the reference database. Using two independent datasets generated on the R9.4 flow cell chemistry, Athlon achieved a 100% accuracy in class I HLA typing at the 2-field resolution
Chemical engineering of the peptidyl transferase center reveals an important role of the 2âČ-hydroxyl group of A2451
The main enzymatic reaction of the large ribosomal subunit is peptide bond formation. Ribosome crystallography showed that A2451 of 23S rRNA makes the closest approach to the attacking amino group of aminoacyl-tRNA. Mutations of A2451 had relatively small effects on transpeptidation and failed to unequivocally identify the crucial functional group(s). Here, we employed an in vitro reconstitution system for chemical engineering the peptidyl transferase center by introducing non-natural nucleosides at position A2451. This allowed us to investigate the peptidyl transfer reaction performed by a ribosome that contained a modified nucleoside at the active site. The main finding is that ribosomes carrying a 2âČ-deoxyribose at A2451 showed a compromised peptidyl transferase activity. In variance, adenine base modifications and even the removal of the entire nucleobase at A2451 had only little impact on peptide bond formation, as long as the 2âČ-hydroxyl was present. This implicates a functional or structural role of the 2âČ-hydroxyl group at A2451 for transpeptidation
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