Technische Universität Berlin

8897 Items

Recent Submissions
Presenting a Spatial-Geometric EEG Feature to Classify BMD and Schizophrenic Patients

Alimardani, Fatemeh ; Boostani, Reza ; Blankertz, Benjamin (2016)

Schizophrenia (SZ) and bipolar mood disorder (BMD) patients demonstrate some similar signs and symptoms; therefore, distinguishing those using qualitative criteria is not an easy task especially when these patients experience manic or hallucination phases. This study is aimed at classifying these patients by spatial analysis of their electroencephalogram (EEG) signals. In this way, 22-channels ...

Kinetic investigation of selective alkane activation

Schulz, Christian (2019)

Since the discovery of vanadyl pyrophosphate (VO)2P2O7 (VPP) based catalysts in the 1970s, major efforts were put in understanding the reaction network of the selective oxidation of n-butane to maleic anhydride (MAN). Although a significant improvement of the yield could be realized since then by advanced synthesis protocols, the selectivity of MAN is limited to 70% at an industrially relevant ...

Ensembles of adaptive spatial filters increase BCI performance: an online evaluation

Sannelli, Claudia ; Vidaurre, Carmen ; Müller, Klaus-Robert ; Blankertz, Benjamin (2016-05-17)

Objective: In electroencephalographic (EEG) data, signals from distinct sources within the brain are widely spread by volume conduction and superimposed such that sensors receive mixtures of a multitude of signals. This reduction of spatial information strongly hampers single-trial analysis of EEG data as, for example, required for brain–computer interfacing (BCI) when using features from spont...

Multiscale temporal neural dynamics predict performance in a complex sensorimotor task

Samek, Wojciech ; Blythe, Duncan A. J. ; Curio, Gabriel ; Klaus-Robert, Müller ; Blankertz, Benjamin ; Nikulin, Vadim V. (2016-07-09)

Ongoing neuronal oscillations are pivotal in brain functioning and are known to influence subjects' performance. This modulation is usually studied on short time scales whilst multiple time scales are rarely considered. In our study we show that Long-Range Temporal Correlations (LRTCs) estimated from the amplitude of EEG oscillations over a range of time-scales predict performance in a complex ...

On diffusion coefficients of multicomponent liquid mixtures predicted by equilibrium molecular dynamics simulation

Janzen, Tatjana (2019)

In the present thesis equilibrium molecular dynamics simulation and the Green-Kubo formalism were employed for the investigation of diffusion coefficients of liquid mixtures. The capability of the utilized simulation method and molecular models to predict composition dependent transport properties was tested by examining 20 binary mixtures composed of methanol, ethanol, acetone, benzene, cycloh...

Jahresbericht 2018 / Technische Universität Berlin und Universität der Künste, Universitätsbibliotheken

(2019)

Im vierten gemeinsamen Jahresbericht stellen die beiden Universitätsbibliotheken der Technischen Universität Berlin (TU Berlin) und der Bibliothek der Universität der Künste Berlin (UdK Berlin) im Rückblick auf das Jahr 2018 zwei gemeinsame Themen in den Mittelpunkt: das Projekt „Leit- und Orientierungssystem“ sowie die Arbeit der Fachreferentinnen und Fachreferenten. Letztere werden individuel...

Comparison of energy stable simulation of moving contact line problems using a thermodynamically consistent Cahn–Hilliard Navier–Stokes model

Bonart, Henning ; Kahle, Christian ; Repke, Jens-Uwe (2019-09-19)

Liquid droplets sliding along solid surfaces are a frequently observed phenomenon in nature, e.g., raindrops on a leaf, and in everyday situations, e.g., drops of water in a drinking glass. To model this situation, we use a phase field approach. The bulk model is given by the thermodynamically consistent Cahn– Hilliard Navier–Stokes model from [Abels et al., Math. Mod. Meth. Appl. Sc., 22(3), 2...

Direct Numerical Simulations of Liquids on Microstructured Surfaces: Analysing the Fluid Dynamics on Packing

Bonart, Henning ; Repke, Jens-Uwe (2018)

Structured high performance packing for packing columns have macrostructures, e.g., corrugated or folded sheets, and in many cases microstructures or surface topographies with geometrical dimensions in the same order of magnitude as the film thicknesses. For an optimal design of microstructured surfaces and for the development of novel methodologies to predict the mass transfer, a reliable desc...

Influence of Liquid Density and Surface Tension on the Pinning of Sliding Droplets on a Triangular Microstructure

Bonart, Henning ; Jung, Johannes ; Kahle, Christian ; Repke, Jens-Uwe (2019-06-11)

Sliding droplets are crucial in many industrial applications. Examples are coating and separation processes involving multiple phases and liquid films. Often one can observe how a sliding droplet halts midstream on a solid surface. Wetting defects such as topographic structures can lead to a pinning of sliding droplets. In order to assess the influence of liquid density and surface tension on t...

Cryogenic energy storage systems

Hamdy, Sarah (2019)

Grid-scale energy storage systems are capable of providing the needed flexibility to the power grid operators in order to ensure a secure power supply with increasing shares of highly intermittent electricity generation from renewable energy sources. Cryogenic energy storage (CES) is a grid-scale energy storage concept in which electricity is stored in the form of liquefied gas enabling a remar...

Experimental characterization of stable liquid rivulets on inclined surfaces: Influence of surface tension, viscosity and inclination angle on the interfacial area

Bonart, Henning ; Marek, André ; Repke, Jens-Uwe (2017-07-22)

In this work, liquid rivulets on inclined, smooth surfaces were examined experimentally using light-induced fluorescence. The influence of viscosity, surface tension and inclination angle was studied in terms of the Reynolds and Kapitza numbers. Detailed results on the interfacial area of the rivulets were obtained. Based on the experimental results, a correlation of the interfacial area in dep...

Potenziale eines Dieselmotors mit variablem Ventiltrieb und Zylinderzuschaltung in einem Traktor

Buitkamp, Thomas (2019)

Ziel aktueller Forschungen an Verbrennungsmotoren ist die weitere Reduzierung der Abgasschadstoffemissionen bei gleichzeitiger Senkung des Kraftstoffverbrauches. Die daraus resultierenden Maßnahmen bedeuten oftmals eine Steigerung der Komplexität der Verbrennungskraftmaschine, womit einerseits die Herstellungskosten steigen, andererseits die Fehleranfälligkeit des Gesamtsystems zunimmt. Es ist ...

Untersuchung der Mechanismen zur Wärmeübertragung in Direktkontaktlatentwärmespeichern

Kunkel, Sven (2019)

Die Energiewende in Deutschland ist in vollem Gange. Durch den gezielten Ausbau der erneuerbaren Energien steigt gleichzeitig der Anteil der fluktuierenden Energiequellen entsprechend an. Dies erfordert effiziente und wirtschaftliche Speichertechnologien zum Ausgleich der Diskrepanz zwischen Energieangebot und -nachfrage. Ebenfalls wird eine solche Speichertechnologie zur effizienten Nutzung vo...

Prozessierung und Anwendung SiO2 basierter Lichtleiter für die optische UVC-Gassensorik

Elmlinger, Philipp Simon (2019)

Diese Arbeit behandelt die Prozessierung verlustarmer Lichtwellenleiter für einen optischen UVC-Gassensor. Durch optische Simulationen wurde zunächst ein geeignetes Material (amorphes Quarzglas) und Design abgeleitet. Mittels Belichtung mit einem Ultrakurzpulslaser und anschließendem selektiven Nassätzen wurden die Lichtleiter aus dem Wafer strukturiert. Die resultierenden rauen Seitenwände füh...

ECoG high gamma activity reveals distinct cortical representations of lyrics passages, harmonic and timbre-related changes in a rock song

Sturm, Irene ; Blankertz, Benjamin ; Potes, Cristhian ; Schalk, Gerwin ; Curio, Gabriel (2014-10-13)

Listening to music moves our minds and moods, stirring interest in its neural underpinnings. A multitude of compositional features drives the appeal of natural music. How such original music, where a composer's opus is not manipulated for experimental purposes, engages a listener's brain has not been studied until recently. Here, we report an in-depth analysis of two electrocorticographic (ECoG...

Bedeutung der Elektrolytverteilung in Blei-Säure Batteriezellen

Wipperfürth, Walter (2019)

This thesis presents the effects of electrolyte distribution in relation to the active material in lead-acid battery cells. The disadvantages of an insufficiently even and sufficient distribution of the electrolyte are presented by means of experiment results in order to show proposals for the optimization of battery capacity and energy density. Instructions for the improvement of the distrib...

Inferring network properties of cortical neurons with synaptic coupling and parameter dispersion

Roy, Dipanjan ; Jirsa, Viktor (2013-03-26)

Computational models at different space-time scales allow us to understand the fundamental mechanisms that govern neural processes and relate uniquely these processes to neuroscience data. In this work, we propose a novel neurocomputational unit (a mesoscopic model which tell us about the interaction between local cortical nodes in a large scale neural mass model) of bursters that qualitatively...

Manganese L-edge spectroscopy of the photosystem II protein and metal complexes in solution

Kubin, Markus (2019)

Photosynthetic water splitting is catalyzed at a Mn4CaO5 complex in the photosystem II protein (PS II). A fundamental understanding of this reduction-oxidation reaction requires detailed information on the electronic structure of the Mn4CaO5 complex and its changes during the water splitting reaction. Important properties of this electronic structure, relevant for a mechanistic understanding of...

Computational models of spatial representations

Weber, Simon Nikolaus (2019)

Our sense of location depends on a structure deep within the brain called the hippocampal formation, and on its neighbor, the parahippocampal region. Studies in rodents have shown that these brain areas contain different types of neurons that help the animal to work out where it is. The activity of those neurons is modulated by the trajectory of the animal, and this modulation varies among cell...

Convex geometry of numbers: covering, successive minima and Banach-Mazur distance

Xue, Fei (2019)

This thesis addresses several classical problems in convex geometry of numbers, including the lattice point covering problem, successive-minima-type inequalities and the Banach-Mazur distance of convex bodies. In the first chapter we will introduce basic concepts, definitions and results which provide the background for the problems in this thesis. Other concepts which are more specific or lim...