Technische Universität Berlin

6642 Items

Recent Submissions
Neue Untersuchungs- und Behandlungsmethoden im stationären Sektor

Ex, Patricia (2018)

Die Finanzierung neuer Gesundheitstechnologien im stationären Sektor erfolgt oft über Entgelte für Neue Untersuchungs- und Behandlungsmethoden (NUB-Entgelte) als temporäres Erstattungsinstrument. Mehr als zehn Jahre nach ihrer Einführung gibt es kaum Studien über NUB-Entgelte und wie sie die Anwendung und Verbreitung von neuen Gesundheitstechnologien beeinflussen. Auch die Ergänzung einer Nutze...

Structure and molecular dynamics of thin films of homopolymers and miscible polymer blends

Madkour, Sherif A. (2018)

In recent years, research on nanoscale confinement of polymers has witnessed topical investigations in attempt to tune polymer properties on demand. One of the most studied forms of nanoconfinement are thin films, where 1D confinement results from the reduction of the film thickness. For these systems, it is crucial to understand how confinement affects the glass transition phenomenon and the a...

Firm strategies and consumer behavior under market-based sustainability policies

Naegele, Helene Blanche (2018)

This dissertation studies different approaches to sustainability regulation. The author evaluates the effectiveness of several policy measures in achieving their objective and discusses potential unintended side-effects. Both depend on strategic firm behavior and consumer sensitivity. Chapter II considers the impact of fuel taxes on the fuel efficiency of new automobiles. The results rely on e...

Advanced Raman spectroscopy for bioprocess monitoring

Kögler, Martin (2018)

The Raman -effect was discovered almost 90 years ago. It took a long time until the importance of Raman spectroscopy was fully understood and accepted for process industrial applications. Still today the usage is limited to a small application area. During the last decades advances in the production of spectroscopic components have reduced the complexity of the instrumentation and further media...

Modelling of coalescence in turbulent liquid/liquid dispersions considering droplet charge

Kamp, Johannes ; Nachtigall, Stephanie ; Maaß, Sebastian ; Kraume, Matthias (2012)

Drop size distributions in liquid/liquid systems within a turbulent flow, being an integral part of many technical applications, can be simulated solving population balance equations. Experimental investigations in stirred toluene/water systems at constant ionic strength of 0.1 mol/L showed that with pH values higher than 11, coalescence is hindered considerably due to electrostatic effects. Wi...

Influence of drop size and superimposed mass transfer on coalescence in liquid/liquid dispersions - Test cell design for single drop investigations

Kamp, Johannes ; Kraume, Matthias (2014)

The detailed understanding of droplet coalescence is important for the accurate description of liquid/liquid dispersions. A test cell is designed which enables serial examinations of the random coalescence process with high repetition rate, good observability and accuracy of experimental parameters. Within this rectangular test cell a rising droplet collides with a pendant one, while recorded b...

Coalescence efficiency model including electrostatic interactions in liquid/liquid dispersions

Kamp, Johannes ; Kraume, Matthias (2015)

The drop size distribution is an essential process variable in liquid/liquid systems and relevant in many technical applications. It can be described by population balance equations. A coalescence efficiency model was developed to be able to describe the well-known coalescence inhibition due to changing pH value or salt concentration. The model includes the attractive van der Waals and repulsiv...

Automated image analysis for trajectory determination of single drop collisions

Kamp, Johannes ; Hänsch, Ronny ; Kendzierski, Gregor ; Kraume, Matthias ; Hellwich, Olaf (2016)

The fundamental analysis of drop coalescence probability in liquid/liquid systems is necessary to reliably predict drop size distributions in technical applications. For this crucial investigation two colliding oil drops in continuous water phase were recorded with different high speed camera set-ups under varying conditions. In order to analyze the huge amount of recorded image sequences with ...

From single drop coalescence to droplet swarms - Scale-up considering the influence of collision velocity and drop size on coalescence probability

Kamp, Johannes ; Kraume, Matthias (2016)

Coalescence modelling in liquid/liquid dispersions is a challenging task and field of investigations up to now, which becomes apparent when comparing the various existent models with their different and partly even contradictive implementation of influencing factors. In this work, systematic investigations of single drop coalescence were used to compare and validate different coalescence effici...

Drop coalescence in technical liquid/liquid applications

Kamp, Johannes ; Villwock, Jörn ; Kraume, Matthias (2016)

The coalescence phenomenon of drops in liquid/liquid systems is reviewed with particular focus on its technical relevance and application. Due to the complexity of coalescence, a comprehensive survey of the coalescence process and the numerous influencing factors is given. Subsequently, available experimental techniques with different levels of detail are summarized and compared. These techniqu...

Not just the what and how, but also the who: the impact of entrepreneurship educators

Steiner, Susanne (2014)

The profile of entrepreneurship educators is as unexplored as it is diverse. While many studies in entrepreneurship education (EE) look at students and their entrepreneurial learning process (e.g., Peterman and Kennedy, 2003; Fayolle et al., 2006; Pittaway and Cope, 2007; Müller, 2009), they have so far paid little attention to the profiles of educators. Educators’ profiles, however, might pla...

Entrepreneurship education in the age of effectuation: teaching strategies evidence from Mexico and Germany

Guerrero, Maribel ; Steiner, Susanne (2011)

The positive impact of Entrepreneurship on economic development has been supported by many research studies (Drucker 1985). Based on those, education and training have been confirmed as relevant factors in promoting and fostering an entrepreneurial perspective (Gibb 1994; Peterman and Kennedy 2003; Kuratko 2005; Pittaway and Cope 2007). Therefore, universities have increasingly incorporated ent...

Show me the money: the impact of funding on entrepreneurship education at German universities

Steiner, Susanne ; Kratzer, Jan ; Haase, Heiko (2013)

This article examines the current characteristics of Entrepreneurship Education (EE) at German universities. We first assess the degree of alignment between course objectives and corresponding contents on an individual course level. As a result, we find a low degree of alignment. In the second part of our analysis we show that the German universities in our sample predominantly use internal fun...

Off-Axis Electron Holographic Focal Series of GaN

Niermann, Tore (2014)

This is a high resolution off-axis electron hologram series obtained with a transmission electron microscope of a Gallium Nitride (GaN) crystal in <11-20> zoneaxis orientation at atomic resolution. It contains the raw data of two holographic focal series obtained under equal conditions (no strong changes in illumination or microscope setup) a few minutes apart. The first series is a focal serie...

Messdaten zur Absorptionskälteanlage FA2

Kühn, Annett (2018-02-09)

This contribution provides measured data of a single stage H2O/LiBr absorption chiller under partload conditions.

Politik und Religion im spätrepublikanischen Rom

Bergemann, Claudia (1989)

Erscheinungsbild und Ursachen der spätrepublikanischen Krise gelten gerade nach den fruchtbaren Bemühungen der Forschung in den letzten Jahrzehnten als hinreichend reflektiert; in den seltensten Fällen jedoch ist das Sakralwesen in die Betrachtungen einbezogen worden. Die Kultgepflogenheiten der Römer zu dokumentieren, blieb weitgehend Domäne der Religionshistoriker, die sich der Aufgabe in all...

Nitrogen and vacancy clusters in ZnO

Tuomisto, Filip ; Rauch, Christian ; Wagner, Markus R. ; Hoffmann, Axel ; Eisermann, Sebastian ; Meyer, Bruno K. ; Kilanski, Lukasz ; Tarun, Marianne C. ; McCluskey, Matthew D. (2013)

Understanding the interaction of group V impurities with intrinsic defects in ZnO is important for developing p-type material. We have studied N-doped ZnO thin films and N-doped bulk ZnO crystals, with positron annihilation spectroscopy, in contrast to earlier studies that have concentrated on N-implanted ZnO crystals. We show that the introduction of N impurities into ZnO, irrespective of whet...

24 GHz low-power switch-channel CMOS transceiver for wireless localization

Zhang, Tao ; Hamidian, Amin ; Shu, Ran ; Subramanian, Viswanathan (2014)

A 24 GHz low-power transceiver is designed, fabricated, and characterized using 130 nm complementary metal-oxide semiconductor (CMOS) process. The designed transceiver is targeted for frequency-modulated-continuous-wave (FMCW) wireless local positioning. The transceiver includes four switchable receiving channels, one transmitting channel and local-oscillator generation circuitries. Several pow...

Evaluation of GaN-HEMT power amplifiers using BST-based components for load modulation

Arnous, Mhd. Tareq ; Wiens, Alex ; Saad, Paul ; Preis, Sebastian ; Zhang, Zihui ; Jakoby, Rolf ; Böck, Georg (2014)

In this paper, the concept of load-modulated power amplifiers (PAs) is studied. Two GaN-HEMT power amplifiers (PAs), targeted for high efficiency at maximum and output back-off (OBO) power levels, are designed, implemented, and tested across 1.8–2.2 GHz. The load modulation in the first design is realized by tuning the shunt capacitors in the output matching network. A novel method is employed ...

Design and analysis of 80-W wideband asymmetrical Doherty amplifier

Bathich, Khaled ; Böck, Georg (2014)

This paper presents the analysis and design of a wideband asymmetrical Doherty amplifier. The frequency response of the output combining network of the Doherty amplifier with arbitrary back-off level configuration is analyzed. Other bandwidth-limiting factors were discussed and analyzed as well. A number of performance enhancement techniques were taken into consideration to obtain high and flat...