Publications

Members of TU Berlin can publish different kinds of (text) publications on DepositOnce:

  • publications with academic content such as monographs and collected editions, journal articles and book chapters, conference proceedings and conference papers, research reports,
  • publications that must be made public in connection with examination regulations (doctoral theses and post-doctoral theses),
  • theses of TU Berlin students if the thesis has received the grade "very good" and the publication is endorsed by the supervisor or referee.

The following publication types can be selected: Doctoral thesis, Habilitation, Master thesis, Bachelor thesis, Book, Conference Proceedings, Periodical Part, Preprint, Report, Research Paper, Article, Book Part, Conference Object

For further information on requirements and workflows see Checklists and Hints for Publishing.

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Recent Submissions

Now showing 1 - 20 of 16356
  • MODUS-COVID Bericht vom 22.02.2024

    Das MODUS-COVID Projekt zielt darauf ab, innovative Methoden und Modelle für die Vorhersage und Analyse der Ausbreitung von Infektionskrankheiten mit einem Fokus auf COVID-19 zu entwickeln. Ein wesentliches Element unserer Arbeit ist unser agentenbasiertes Modell Episim, welches individuelle Verhaltensweisen und Interaktionen innerhalb der Bevölkerung abbildet, um so die Infektionsdynamik zu simulieren. Allerdings stoßen agentenbasierte Modelle (ABMs) bei der Simulation großer Populationen oder Regionen oft an ihre Grenzen, insbesondere hinsichtlich der Rechenleistung und Skalierbarkeit. Um diese Einschränkungen zu überwinden, haben wir einen neuen, hybriden Modellierungsansatz entwickelt. Unser Ansatz kombiniert die Vorteile von agentenbasierten Modellen mit Kompartimentmodellen. Durch diese Kombination ist es möglich, die detaillierte Simulation von individuellem Verhalten, die durch das ABM ermöglicht wird, mit der effizienteren Berechnung von Infektionsdynamiken auf größeren Skalen zu vereinen. In diesem Bericht präsentieren wir die grundlegende Architektur unseres hybriden Modells.
  • Effect of resting time on rheological properties of glass bead suspensions: Depletion and bridging force among particles

    The effect of resting time on the rheological properties of cement suspensions is generally explained by early formed structure and overconsumption of polycarboxylate superplasticizers (PCEs). In this paper, we propose that the influence of resting time on the rheological properties is closely related to size variation of non‐absorbed PCE. To identify this, glass bead suspensions were prepared with various amounts of PCE and ionic solution, and their rheological properties were evaluated at various times. We found that the yield stress increases with time at higher PCE concentrations and higher ionic strength solutions. Adsorbed PCE during resting tends to bridge the particles rather than disperse them. In addition, it was found that hydrodynamic radius of PCE increased with resting time, and depletion forces resulting from non‐absorbed PCE size changes correlate well with the increased yield stress.
  • Software‐in‐the‐loop simulation for developing and testing carbon‐aware applications

    The growing electricity demand of IT infrastructure has raised significant concerns about its carbon footprint. To mitigate the associated emissions of computing systems, current efforts therefore increasingly focus on aligning the power usage of software with the availability of clean energy. To operate, such carbon-aware applications require visibility and control over relevant metrics and configurations of the energy system. However, research and development of novel energy system abstraction layers and interfaces remain difficult due to the scarcity of available testing environments: Real testbeds are expensive to build and maintain, while existing simulation testbeds are unable to interact with real computing systems. To provide a widely applicable approach for developing and testing carbon-aware software, we propose a method for integrating real applications into a simulated energy system through software-in-the-loop simulation. The integration offers an API for accessing the energy system, while continuously modeling the computing system's power demand within the simulation. Our system allows for the integration of physical as well as virtual compute nodes, and can help accelerate research on carbon-aware computing systems in the future.
  • Wet‐Oxidative Desulfurization as a Flexible and Greener Way for H2S Removal from Acid Gases

    In wet-oxidative gas desulfurization processes, absorbed H2S is directly converted to sulfur by a redox catalyst dissolved in a circulating scrubbing solution. High flexibility is achieved through the availability of different catalyst classes. In this work, a process based on the Takahax process was investigated in a pilot plant under industrially relevant conditions with coke oven gas. A stable plant operation without sulfur precipitation was achieved by a suitable choice of the operating conditions. The solid-free operating window was determined and a sulfur redissolution strategy developed.
  • Entwicklung und Untersuchung verschiedener Maßnahmen zur Strukturierung des Berliner Reisebusverkehrs mithilfe einer agentenbasierten Verkehrssimulation

    Der Reisebus ist aus der Perspektive der CO₂-Emissionen pro Personenkilometer ein umweltfreundliches Fortbewegungsmittel. Durch laufende Motoren im Standbetrieb und lange Fahrzeiten für die Parkplatzsuche entstehen jedoch negative Auswirkungen auf die Klimabilanz des ansonsten umweltfreundlichen Verkehrsmittels. Daher lässt sich davon ausgehen, dass eine unkoordinierte Führung der Reisebusse zu einer hohen Schadstoff-, Lärm- und Flächenbelastung führt, die wiederum Konflikte zwischen Verkehrsteilnehmer*innen, Anwohnern und Bustourist*innen erzeugt. Das Projektvorhaben zielt daher auf die Erarbeitung eines einheitlichen Reisebuskonzepts ab, um die Schadstoff-, Lärm- und Flächenbelastung durch den Reisebusverkehr zu reduzieren und Konflikten zwischen verschiedenen Verkehrsteilnehmende, Anwohnern und Tourist*innen vorzubeugen. Im Verlauf des Projektes soll mithilfe einer Simulation, welche verschiedene Formen der Organisation des Berliner Reisebusverkehrs abbildet, geprüft werden, welche Strategien die günstigsten sind. Ausgehend von dieser Simulation kann die Einsparung von CO₂-Emissionen/Feinstaubemissionen sowie die effizientere Gestaltung der Beförderung von Tourist*innen für Busunternehmer und die Identifikation von Stellplätzen zum Dauerparken, Kurzparken und als Drop-Off Points ermittelt werden. Der Fokus des Projektvorhabens liegt somit weniger auf dem Reisebusverkehr als solchem, sondern vielmehr auf der Verbesserung der aktuell ineffektiven Betriebsstrukturen, z. B. Vermeidung von unnötigen Fahrten bei der Stellplatzsuche.
  • Recent insights into the world of dual‐function bacterial sRNAs

    Dual-function sRNAs refer to a small subgroup of small regulatory RNAs that merges base-pairing properties of antisense RNAs with peptide-encoding properties of mRNA. Both functions can be part of either same or in another metabolic pathway. Here, we want to update the knowledge of to the already known dual-function sRNAs and review the six new sRNAs found since 2017 regarding their structure, functional mechanisms, evolutionary conservation, and role in the regulation of distinct biological/physiological processes. The increasing identification of dual-function sRNAs through bioinformatics approaches, RNomics and RNA-sequencing and the associated increase in regulatory understanding will likely continue to increase at the same rate in the future. This may improve our understanding of the physiology, virulence and resistance of bacteria, as well as enable their use in technical applications.
  • Controlling the Coke Formation in Dehydrogenation of Propane by Adding Nickel to Supported Gallium Oxide

    Atomic layer deposition was applied on mesoporous silica to synthesize a highly dispersed gallium oxide catalyst. This system was used as starting material to investigate different loadings of nickel in the dehydrogenation of propane under industrially relevant, Oleflex-like conditions. The formation of NiGa alloys was confirmed by X-ray diffraction analysis and electron microscopy. Surprisingly, the nanoalloys enhanced the selectivity towards C3H6 while decreasing the tendency for coking. Herein, in situ thermogravimetry, and measured mass fractions of carbon revealed that the coking rate was reduced by over 50 % compared to the pristine gallium oxide. Generally, the increased selectivity can be explained by the partial hydrogenation and reduction of the gallium oxide surface. The optimum temperature for the removal of deposited carbon was evaluated by a temperature programmed oxidation. Finally, the best-performing Ni−GaOx catalyst was employed in a cycled experiment with periodic reaction and regeneration tests. After regeneration, the selected Ni−GaOx catalyst provided a higher yield of propylene compared to the unmodified gallium oxide.
  • Specific Modification of Granular Potato Starch by Means of Partial Debranching Using Pullulanase

    Native potato starch (PS‐N) is enzymatically modified in the granular state using pullulanase (PUL) for the purpose of a specific partial molecular degradation of the polymers. The PUL compound is added to the aqueous starch suspension (40%, w/w) and processed. The process parameters are varied systematically (enzyme dosage [ENZ] 4/20 mL; pH of the suspension [pH 4.7/7.3]; hydrolysis temperature [TEMP] 40/50 °C, and hydrolysis duration [TIME] 20/120 min) and a new‐developed heat‐induced enzyme inactivation approach (storage of the partially dewatered moist starch for 120 min at 100 °C) is intended to terminate the hydrolysis. Morphological (LM, SEM, and CLSM) and thermal characterization (DSC) of the starch products indicate a partial damage of the granules and a partial loss of the semicrystalline structure owing to the heat treatment, which is confirmed by XRD. The molecular properties (SEC‐MALS‐DRI) are mainly controlled by the factors ENZ, pH, and TEMP, but the intended degradation of the amylopectin (AP) by cleavage of the α‐1,6‐linkages (debranching) is accompanied by a molecular degradation of the amylose (AM) fraction. However, both specificity of the hydrolysis and achievable gel strength are remarkably improved compared to acid‐thinned products.
  • Enzymatic Degradation of Starch—Usage of β‐Cyclodextrin for Inactivation of Pullulanase

    The cyclic oligosaccharide β-cyclodextrin (β-CDx) is investigated regarding its ability on principle to reduce the debranching activity of pullulanase (PUL) or even terminate the enzymatic hydrolysis process of starch polymers completely. For this purpose, dissolved β-CDx (aqueous solution) is mixed with the diluted PUL compound (solution) and conditioned (stirred at 40 °C for various durations [0, 20, 40, and 60 min; at 26.75 nmol β-CDx U−1] and at various β-CDx dosages [5.35, 13.375, 26.75, and 53.5 nmol β-CDx U−1; reaction time 60 min]). The PUL-CDx-mixtures are subsequently added to a 2.5% w/w starch solution (related to the initial specific debranching activity; 1593.6 NPUN g−1/557.8 U g−1) and gently stirred for 20 min at 40 °C before final thermal inactivation. The obtained samples are diluted and characterized molecularly, i.e., by means of size exclusion chromatography (SEC). An increasing β-CDx dosage reduces the degree of molecular degradation systematically reflecting a successively reduced enzyme activity. However, the reaction time (PUL-CDx-mixture) has no impact on the enzyme's activity since the starch degradation is marginally and the SEC-chromatograms similar to the one of the initial starch. Restrictions of the enzyme inhibiting effect of β-CDx are found terminating the hydrolysis process in a starch suspension.
  • Investigation of the Emission Rate of Particles when Musicians Play Wind, Woodwind, and Brass Instruments

    In the context of the high risk of airborne transmission of COVID-19, the question of the production of particles while playing wind instruments is highly relevant. Therefore, in this study, 23 professional musicians played their instruments in a cleanroom in cleanroom-grade clothing. The most common orchestral wind instruments flute, oboe, clarinet, and trumpet were therefore chosen. Aerosol measurements using a laser particle counter were conducted to quantify the emission rate of respiratory particles. Orchestral excerpts as well as sustained tones in two dynamic levels were played. The emitted particles were mostly in a submicron size range. For all instruments besides the clarinet, an influence of the loudness of playing on the emission rate could be observed. The emission rates for all musical instruments were independent of the passages played. Flute and oboe showed similar emission rates but lower than the values for clarinet and trumpet. While playing a note with a small volume, the flute, oboe, and trumpet have a similar emission rate as found for speaking.
  • In situ/operando plug-flow fixed-bed cell for synchrotron PXRD and XAFS investigations at high temperature, pressure, controlled gas atmosphere and ultra-fast heating

    A plug-flow fixed-bed cell for synchrotron powder X-ray diffraction (PXRD) and X-ray absorption fine structure (XAFS) idoneous for the study of heterogeneous catalysts at high temperature, pressure and under gas flow is designed, constructed and demonstrated. The operating conditions up to 1000°C and 50 bar are ensured by a set of mass flow controllers, pressure regulators and two infra-red lamps that constitute a robust and ultra-fast heating and cooling method. The performance of the system and cell for carbon dioxide hydrogenation reactions under specified temperatures, gas flows and pressures is demonstrated both for PXRD and XAFS at the P02.1 (PXRD) and the P64 (XAFS) beamlines of the Deutsches Elektronen-Synchrotron (DESY).
  • Decoding Antisemitism: An AI-driven Study on Hate Speech and Imagery Online. Discourse Report 6

    The interdisciplinary research project "Decoding Antisemitism" aims to investigate antisemitism on the internet. Since summer 2020, this three-year pilot project has been based at the Centre for Research on Antisemitism (ZfA) at TU Berlin and is being carried out in cooperation with King's College London (KCL). The object of study is antisemitism in the comment sections of mainstream political media websites in Germany, France and the UK, as well as their social media profiles. Using a mixed methods approach, discursive trends in the three European countries and different verbal and visual forms of antisemitism are analysed qualitatively, quantitatively and with the help of AI. The interactive web presents itself as an object of study due to its central role in social discourse. By analysing the comments sections of media that belong to the politically moderate field, the research team is opening up a field that has received little attention so far - an urgent task, since the normalisation of derogatory and exclusionary rhetoric in such milieus poses an enormous danger. On the basis of extensive qualitative analyses, an overview of previously unknown manifestations and the actual extent of antisemitism in these European web communities will be gained. The results in turn offer the possibility of diverse counter-strategies.
  • 3D super-resolution cardiac parametric mapping

    Cardiovascular magnetic resonance imaging (MRI) has become the standard method for assessing cardiac function, volumes, and mass and characterizing myocardial tissue composition. Compared to other imaging techniques, cardiac MRI is unique in its ability to accurately characterize the composition of myocardial tissue without any ionizing radiation. Current cardiac MRI techniques typically obtain qualitative images, which commonly only allow for the detection of focal pathologies and are difficult to compare between different scans or institutions. To address this issue, T1 mapping can be used, which yields quantitative T1 relaxation times of each voxel within the field of view. This allows for the identification of altered tissue characteristics associated with oedema, fibrosis, and infiltrative diseases. T1 mapping has the potential to detect both focal and diffuse diseases and to assess early asymptomatic tissue remodelling. However, the lengthy examination time, low spatial through-plane resolution, and limited spatial coverage limit its clinical application. In this thesis, new methods were developed to address these limitations and obtain a whole-heart high-resolution (HR) three-dimensional cardiac T1 map in a short acquisition time of three minutes. For that, two-dimensional slices were acquired using a fast, continuous Golden radial angle sequence with a high in-plane but low through-plane resolution. A k-space-based super-resolution reconstruction (SRR) approach was then used to reconstruct three-dimensional HR slices from the acquired low-resolution (LR) data. A radial SRR acquisition geometry of the LR datasets allowed a whole-heart coverage. Small structures, such as the atrial or right ventricular walls, could be visualized. The presented techniques were evaluated in simulation and phantom experiments, and feasibility was shown in healthy volunteers. The imaging approaches proposed in this thesis show promise for obtaining HR parameter maps of cardiac tissues in a short acquisition time. This approach is versatile and could be used to quickly acquire multiple quantitative parameter maps, such as simultaneous T1 and T2 mapping of the entire heart in future studies.
  • Chemical electron microscopy of perimeter structures in bimetallic nanocatalyst systems

    Currently, scientists seek energy conversion options that are both environmentally and economically sustainable. A promising option is the use of transition-metal containing layered double hydroxides (LDH) as catalyst precursors. In addition, employing a combination of two metals in a bimetallic system can improve the catalyst’s properties compared to monometallic materials. The nickel and copper bimetallic systems are interesting combinations for catalyst applications. However, there are still open research questions due to contradictory results. Some previous research has reported a miscibility gap for thin films of Ni-Cu; a point where the two elements do not form an alloy or solid solution that is often omitted within investigations of supported nanoalloys. In addition, more research is needed to understand the structure-function relationship of Ni-Cu bimetallic catalysts derived from LDH precursors. The aim of this thesis was to study the Ni-Cu bimetallic catalysts using materials derived LDH precursor. Through chemical electron microscopy as a primary characterization technique, combined with complementary techniques (thermogravimetric analysis, temperature-programmed reduction, X-ray diffraction, X-ray photoelectron spectroscopy, near edge X-ray adsorption fine structure, among others), we unraveled the properties of the materials after synthesis, activation, and catalytic testing. The catalytic evaluation entailed two paragon examples of current importance: carbon dioxide hydrogenation and ammonia decomposition reactions. In addition, owing to the significance of transmission electron microscopy (TEM) analysis in this thesis and the potential damage during electron-matter interaction, a systematic analysis of beam damage in the TEM was conducted for the first time for this LDH system. The analysis describes the structural changes resulting from electron beam irradiation on LDH and derived materials. First, four materials with different Ni:Cu metal compositions were chosen and synthesized from an LDH precursor, using carbonates as interlayer anions and Al as support: two with a monometallic (NiAl and CuAl), and two with a bimetallic (NiCu(4:1)Al and NiCu(1:1)Al) composition. The results showed that all LDH samples presented platelet-like morphology. The calcination process transformed the metal hydroxides into mixed metal oxides (MMO), where the Al2O3 remained amorphous. The study of the activation process highlighted three main aspects. (1) Mild calcination at 290 °C, in contrast to 600 °C as a harsh calcination method, helped to lower the reduction temperature of Ni-containing samples, probably by avoiding the formation of a Ni-spinel structure. (2) The presence of low amounts of copper (Ni/Cu ratio = 4), usually atomically dispersed, promoted the reducibility of nickel by reducing the temperature of the reduction peak by 100 °C. (3) Upon reduction at 450 °C, the samples containing Ni exhibited uniformly dispersed nanoparticles with a particle size of 3.7 nm. The bimetallic samples showed an enrichment of Cu at their surfaces. Further investigation with in situ XRD using NiCu(4:1)Al sample suggested that above 600 °C the Cu from the surface was incorporated into the Ni lattice forming an alloy. Catalytic evaluation on the selected reactions showed the different roles of nickel and copper species. During CO2 hydrogenation at atmospheric pressure and various temperatures (from 500 to 600 °C), Ni promoted methanation, whereas adding Cu suppressed such methane formation by improving CO selectivity (RWGS activity). On ammonia decomposition at ambient pressure, the Ni particles - potential active centers - were blocked by adding Cu. This significantly decreased hydrogen production. Characterization of the spent catalysts showed that Ni may provide stability to the catalysts, especially noticeable during CO2 hydrogenation. When Cu was added in a 1:1 ratio, remarkable segregation occurred after both reactions. Here, Cu particles with sizes above 100 nm were visible. Furthermore, we performed detailed experiments on one bimetallic sample using operando TEM. A striking CO and H2O production for CO2 hydrogenation was observed at 800 mbar and 600 °C. The results presented here have sparked further research questions, with operando TEM being identified as a promising method for gaining a more comprehensive understanding of atomic-level changes in a working catalyst. In conclusion, the findings reported in this dissertation contributed to the fundamental understanding of Ni-Cu bimetallic systems, particularly derived from LDH precursors. We emphasized their bimetallic functionalities in key reactions for a possible H2-based economy, such as CO2 hydrogenation and ammonia decomposition reactions.
  • Perspectives on road transport decarbonization in Europe

    The decarbonization of road transport is a central challenge for the transition to climate neutrality. There is, however, considerable debate on suitable instruments for achieving zero-emissions road transportation. A range of alternative technologies could prove to be suitable to this aim, namely battery electric vehicles, fuel-cell electric vehicles and e-fuels. In parallel to the technological dimension, the relative roles of carbon pricing and other sector-specific policies is currently discussed at a political level. Transport-specific bottom-up models are generally used to analyse the technological and behavioural factors involved in road transport decarbonization, while large scale energyeconomy-environment models offer the fitting framework for exploring the impact of transport decarbonization on the wider system as well as the effectiveness of top-down measures such as carbon taxation. With the aim of contributing to the model-based research field studying the transport decarbonization opportunities, I co-developed a detailed transport model, EDGE-T, and soft-linked it with an Integrated Assessment Model (IAM), REMIND. The purpose of EDGET is to provide a detailed environment to evaluate transport-specific policies, with a fine-grained representation of technological options and transport alternatives. REMIND on the other hand provides a coherent framework of the full energy-economy system, which ensures the consistency of transportation demand with economic drivers, the energy supply system, and competing demands from other energy end-uses. This system hence features the feedback between the competition for scarce resources at a macroeconomic level and the transport related technological and modal choices. The EDGE-T model can be both used as a stand-alone model to provide detailed transport specific analyses as well as in combination with REMIND. In the stand-alone version, EDGE-T can easily be tested, improved and updated as technologies advance and new knowledge about transport sector decarbonization options becomes available. Soft-linking EDGE-T with the IAM allows to perform full-system analyses featuring both supply and demand sectors, maintaining the high detail on the transport representation via the iterative coupling. With the obtained modelling framework, I first focus on the technological dimension and explore a range of electrification pathways for light-duty vehicles in Europe. I find that direct electrification has the potential for a substantial decarbonization of road-based private passenger transportation. Indirect electrification via H2 or synthetic fuels is in principle also viable, but would imply a significantly higher energy demand and would be less effective due to the lower maturity of the required technologies, their higher cost and the low energy efficiency of the production chain. I then broaden the analysis to the whole European road sector, analysing the separate and combined decarbonization potential of alternative policy packages, namely carbon taxation and internal combustion engines phase-out. My results indicate that phase-out policies can substantially accelerate the transition in the road transport segment, while a carbon tax alone has a smaller impact on consumer choices and emissions. However, carbon tax and phaseout policies are complementary, as phase-out policies alone accelerate the demand-side transition but are unable to incentivize the decarbonization of the energy supply. In sum, this thesis explores a range of decarbonization pathways for the road transport sector in Europe. The main tool used for this analysis is a flexible and detailed transport model featuring a variety of transport modes and powertrain options soft-linked to an IAM. The unique features of this modelling setup allow to combine a rich set of transport decarbonization options, namely technological shift, energy-supply transformation and activity reduction with a coherent and detailed representation of the rest of the economy and the energy sector.
  • Ghost material in geotechnical applications of the CEL method

    The Coupled-Eulerian-Lagrangian (CEL) method is an established numerical approach for the simulation of geotechnical boundary value problems involving soil–structure interaction and large deformations. A consequence of this approach is the existence of two overlapping numerical meshes, one Lagrangian and one Eulerian. The structure is usually modeled by the Lagrangian part while the soil is represented by the Eulerian part. The material within the Eulerian part of the mesh overlap may be considered a kind of ’virtual’ or ’ghost’ material, as it only exists due to the numerical approach and has no counterpart in reality. Up to now it has never been evaluated how much this ghost material influences the simulation results. In this study, two geotechnical applications of CEL are analyzed which contain ghost material in a zone of soil–structure-interaction. Each example implements several model variants by applying different material combinations and contact formulations. Additional simulations with a pure Arbitrary-Lagrangian-Eulerian (ALE) approach, in which no ghost material exists, are presented to give further insights.
  • Boats as housing in Oxford: Trajectories of Informality in a High‐Income Context

    In this article I aim to shed light on boat dwelling as an increasingly popular housing practice in the UK. I investigate the changing nature of this practice in times of housing crisis and of the connection between formal and informal approaches, and discuss how decentralized urban actors influence and safeguard their visions of housing. My investigation concentrates on three intertwined strategies boaters in Oxford use to deal with growing regularization and commodification pressures: (non)compliance, formalization and staying under the radar. My findings challenge several assumptions about housing informality in the global North and document the diverse trajectories that informal processes may take. My analysis reveals that informal and semi‐formal solutions are not simply ‘tolerated’ or ‘overlooked’ by the state, but co‐produced by urban dwellers through a repertoire of everyday actions and ad hoc advocacy approaches. The construction of specific trajectories of informal housing emerges at the interface of complex agendas and attitudes that go beyond the generalized roles attributed to the key urban sectors.
  • Controlling the photon number coherence of solid-state quantum light sources for quantum cryptography

    Quantum communication networks rely on quantum cryptographic protocols including quantum key distribution (QKD) based on single photons. A critical element regarding the security of QKD protocols is the photon number coherence (PNC), i.e., the phase relation between the vacuum and one-photon Fock state. To obtain single photons with the desired properties for QKD protocols, optimal excitation schemes for quantum emitters need to be selected. As emitters, we consider semiconductor quantum dots, that are known to generate on-demand single photons with high purity and indistinguishability. Exploiting two-photon excitation of a quantum dot combined with a stimulation pulse, we demonstrate the generation of high-quality single photons with a controllable degree of PNC. The main tuning knob is the pulse area giving full control from minimal to maximal PNC, while without the stimulating pulse the PNC is negligible in our setup for all pulse areas. Our approach provides a viable route toward secure communication in quantum networks.
  • Psychoacoustic parameters in noise assessment – A research within the BMDV Network of Experts

    This paper is dedicated to the applicability of psychoacoustic parameters for the evaluation of traffic noise. To characterize road traffic noises in detail and to demonstrate the perceptual impact, knowledge of the underlying dimensions that influence the evaluation of traffic sounds in everyday situations is required. In a study, stimulus-dyad comparisons were used to investigate underlying descriptive variables and attributes describing the latent perceptual dimensions of road traffic sounds. The dyads covered the feature space of road traffic sounds and systematically took into account factors such as traffic volume, traffic flow, traffic composition and road surface. The paper explains the experimental methodology, shows the derived attributes, and outlines the development of a questionnaire as a measurement tool to determine the perception of road traffic sounds in detail.
  • Contributions towards variable temperature shielding for compact NMR instruments

    The application of compact NMR instruments to hot flowing samples or exothermically reacting mixtures is limited by the temperature sensitivity of permanent magnets. Typically, such temperature effects directly influence the achievable magnetic field homogeneity and hence measurement quality. The internal‐temperature control loop of the magnet and instruments is not designed for such temperature compensation. Passive insulation is restricted by the small dimensions within the magnet borehole. Here, we present a design approach for active heat shielding with the aim of variable temperature control of NMR samples for benchtop NMR instruments using a compressed airstream which is variable in flow and temperature. Based on the system identification and surface temperature measurements through thermography, a model predictive control was set up to minimise any disturbance effect on the permanent magnet from the probe or sample temperature. This methodology will facilitate the application of variable‐temperature shielding and, therefore, extend the application of compact NMR instruments to flowing sample temperatures that differ from the magnet temperature.