Modeling of micro- and nanostructures made of films and crystals/fibers arrays

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2013

Micro scale modeling grain boundary damage under creep conditions

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Design, modeling and control of an autonomous field robot for white asparagus harvesting

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Population balance modeling of influenza A virus replication in MDCK cells during vaccine production

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2015

Towards effective research-paper recommender systems and user modeling based on mind maps

Magdeburg, Univ., Fak. für Informatik, Diss., 2015

Analysis study of the axial transport and heat transfer of a flighted rotary drum operated at optimum loading

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2015

Development of a new method for the characterisation of bioreactors concerning heat and mass transfer

Since the specific heat transfer coefficient (UA) and the volumetric mass transfer coefficient (kLa) play an important role for the design of biotechnological processes, different techniques were developed in the past for the determination of these parameters. However, these approaches often use imprecise dynamic methods for the description of stationary processes and are limited towards scale and geometry of the bioreactor. Therefore, the aim of this thesis was to develop a new method, which overcomes these restrictions. This new approach is based on a permanent production of heat and oxygen by the constant decomposition of hydrogen peroxide in continuous mode. Since the degradation of H2O2 at standard conditions only takes place by the support of a catalyst, different candidates were investigated for their potential (regarding safety issues and reaction kinetic). Manganese-(IV)-oxide was found to be suitable. To compensate the inactivation of MnO2, a continuous process with repeated feeds of fresh MnO2 was established. Subsequently, a scale-up was successfully carried out from 100 mL to a 5 litre glass bioreactor (UniVessel®)To show the applicability of this new method for the characterisation of bioreactors, it was compared with common approaches. With the newly established technique as well as with a conventional procedure, which is based on an electrical heat source, specific heat transfer coefficients were measured in the range of 17.1 – 24.8 W/K for power inputs of about 50 – 70 W/L. However, a first proof of concept regarding the mass transfer showed no constant kLa for different dilution rates up to 0.04 h-1.Based on this, consecutive studies concerning the mass transfer should be made with higher volume flows, due to more even inflow rates. In addition, further experiments are advisable, to analyse the heat transfer in single-use bioreactors and in larger common systems.

Dynamics in growth and metabolism of adherent MDCK cells unraveled by an integrated modeling approach

Otto-von-Guericke-Universität Magdeburg, Fakultät für Verfahrens- und Systemtechnik, Univ., Dissertation, 2015

Kommentierte Übersetzung des NASA-Berichtes „Pioneering Space: NASA’s Next Steps on the Path to Mars“ vom Englischen ins Deutsche

Die Bachelorarbeit besteht aus der Übersetzung des NASA-Berichtes „Pioneering Space: NASA’s Next Steps on the Path to Mars“ vom Englischen ins Deutsche und einer Textanalyse nach dem Analysemodell von Christiane Nord. Dieser Analyseansatz wird grob nach den sog. textexternen und textinternen Faktoren aufgeteilt. Zu den Besonderheiten und Herausforderungen der Übersetzung werden u.a. das hohe fachsprachliche Textniveau sowie diverse Abkürzungen und Abteilungsnamen innerhalb der NASA, die im Bericht auftauchen, gehören. Da darüber hinaus die Berichte und Kommunikation in der Weltraumszene hauptsächlich in englischer Sprache erfolgt, muss ein Kompromiss gefunden werden, um die Wörter so im Text einzubringen, dass der Textfluss nicht übertrieben gestört wird.

Modeling usage of medical care services: the medical expenditure panel survey data, 1996-2000

We explore the determinants of usage of six different types of health care services, using the Medical Expenditure Panel Survey data, years 1996-2000. We apply a number of models for univariate count data, including semiparametric, semi-nonparametric and finite mixture models. We find that the complexity of the model that is required to fit the data well depends upon the way in which the data is pooled across sexes and over time, and upon the characteristics of the usage measure. Pooling across time and sexes is almost always favored, but when more heterogeneous data is pooled it is often the case that a more complex statistical model is required.

Likelihood-based approaches to modeling demand for medical care

We review recent likelihood-based approaches to modeling demand for medical care. A semi-nonparametric model along the lines of Cameron and Johansson's Poisson polynomial model, but using a negative binomial baseline model, is introduced. We apply these models, as well a semiparametric Poisson, hurdle semiparametric Poisson, and finite mixtures of negative binomial models to six measures of health care usage taken from the Medical Expenditure Panel survey. We conclude that most of the models lead to statistically similar results, both in terms of information criteria and conditional and unconditional prediction. This suggests that applied researchers may not need to be overly concerned with the choice of which of these models they use to analyze data on health care demand.

Stable rank of leavitt path algebra

We characterize the values of the stable rank for Leavitt path algebras, by giving concrete criteria in terms of properties of the underlying graph.

Turkey's accession to the EU: interests, ideas and path dependence

The paper is divided into four sections. The first offers a critical assessment of explanations of both rationalist and constructivist approaches currently dominating European studies and assesses the notion of path dependence. The second and third sections analyse the role of both material interests and polity ideas in EU enlargement to Turkey, and conclude that explanations exclusively based on either strategic calculations or values and identities have significant shortcomings. The fourth section examines the institutional path of Turkey's candidacy to show how the course of action begun at Helsinki restricted the range of possible and legitimate options three years later in Copenhagen.

Chain conditions for Leavitt path algebras

In this paper, results known about the artinian and noetherian conditions for the Leavitt path algebras of graphs with finitely many vertices are extended to all row-finite graphs. In our first main result, necessary and sufficient conditions on a row-finite graph E are given so that the corresponding (not necessarily unital) Leavitt path K-algebra L(E) is semisimple. These are precisely the algebras L(E)for which every corner is left (equivalently, right)artinian. They are also precisely the algebras L(E) for which every finitely generated left (equivalently, right) L(E)-module is artinian. In our second main result, we give necessary and sufficient conditions for every corner of L(E) to be left (equivalently, right) noetherian. They also turn out to be precisely those algebras L(E) for which every finitely generated left(equivalently, right) L(E)-module is noetherian. In both situations, isomorphisms between these algebras and appropriate direct sums of matrix rings over K or K[x, x−1] are provided. Likewise, in both situations, equivalent graph theoretic conditions on E are presented.