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Today, the use of renewable energies and recycling of climate-changing gases are increasingly important. In this context,coupling of methanation with small, decentralized CO2sources such as biogas plants provides one possibility. However,fluctuating availability of renewables for hydrogen production in combination with small storage volumes result in anenhanced demand for dynamic process operation. This leads to new research challenges with respect to the required cata-lysts and the overall process design. To draw reliable conclusions about the catalytic performance under dynamic processoperation, the mechanism of the methanation reaction as well as typical deactivation procedures of the catalyst appliedunder steady-state conditions have to be reviewed thoroughly.
A swirling pulverized coal flame is computationally investigated. A Eulerian–Lagrangian formulation is used to describe the two-phase flow. Turbulence is modelled within a RANS (Reynolds averaged numerical simulation) framework. Four turbulence viscosity- (TV) based models, namely the standard k-ε model, realizable k-ε model, renormalization group theory k-ε model, and the shear stress transport k-ω model are used. In addition, a Reynolds stress transport model (RSM) is employed. The models are assessed by comparing the predicted velocity fields with the measurements of other authors. In terms of overall average values, the agreement of the predictions to the measurements is observed to be within the range 20–40%. A better performance of the RSM compared to the TV models is observed, with a nearly twice as better overall agreement to the experiments, particularly for the swirl velocity. In the second part of the investigation, the resolution of the discrete particle phase in modelling the turbulent particle dispersion (TPD) and particle size distribution (SD) is investigated. Using the discrete random walk model for the TPD, it is shown that even five random walks are sufficient for an accuracy that is quite high, with a less than 1% mean deviation from the solution obtained by thirty random walks. The approximation of the measured SD is determined by a continuous Rosin–Rammler distribution function, and inaccuracies that can occur in its subsequent discretization are demonstrated and discussed. An investigation on the resolution of the SD by discrete particle size classes (SC) indicates that 12 SC are required for an accuracy with a less than 1% mean deviation from the solution with 18 SC. Although these numbers may not necessarily be claimed to be sufficiently universal, they may serve as guidance, at least for SD with similar characteristics
The PSFC, or Pioneer Sound Field Controller, is a DSP-driven hemispherical loudspeaker array, installed at the University of Aizu Multimedia Center. The PSFC features realtime manipulation of the primary components of sound spatialization for each of two audio sources located in a virtual environment, including the content (apparent direction and distance) and context (room characteristics: reverberation level, room size and liveness). In an alternate mode, it can also direct the destination of the two separate input signals across 14 loudspeakers, manipulating the direction of the virtual sound sources with no control over apparent distance other than that afforded by source loudness (including no simulated environmental reflections or reverberation). The PSFC speaker dome is about 10 m in diameter, accommodating about fifty simultaneous users, including about twenty users comfortably standing or sitting near its ``sweet spot,'' the area in which the illusions of sound spatialization are most vivid. Collocated with a large screen rear-projection stereographic display, the PSFC is intended for advanced multimedia and virtual reality applications.
Actin droplet machine
(2019)
The actin droplet machine is a computer model of a three-dimensional network of actin bundles developed in a droplet of a physiological solution, which implements mappings of sets of binary strings. The actin bundle network is conductive to travelling excitations, i.e. impulses. The machine is interfaced with an arbitrary selected set of k electrodes through which stimuli, binary strings of length k represented by impulses generated on the electrodes, are applied and responses are recorded. The responses are recorded in a form of impulses and then converted to binary strings. The machine's state is a binary string of length k: if there is an impulse recorded on the ith electrode, there is a '1' in the ith position of the string, and '0' otherwise. We present a design of the machine and analyse its state transition graphs. We envisage that actin droplet machines could form an elementary processor of future massive parallel computers made from biopolymers.
To power dynamic processes in cells, the actin and microtubule cytoskeletons organize into complex structures. Although it is known that cytoskeletal coordination is vital for cell function, the mechanisms by which cross-linking proteins coordinate actin and microtubule activities remain poorly understood. In particular, it is unknown how the distinct mechanical properties of different actin architectures modulate the outcome of actin-microtubule interactions. To address this question, we engineered the protein TipAct, which links growing microtubule ends via end-binding proteins to actin filaments. We show that growing microtubules can be captured and guided by stiff actin bundles, leading to global actin-microtubule alignment. Conversely, growing microtubule ends can transport, stretch and bundle individual actin filaments, thereby globally defining actin filament organization. Our results provide a physical basis to understand actin-microtubule cross-talk, and reveal that a simple cross-linker can enable a mechanical feedback between actin and microtubule organization that is relevant to diverse biological contexts.
Camera-based object detection is widely used in safety-critical applications such as advanced driver assistance systems (ADAS) and autonomous vehicle research. Road infrastructure has been designed for human vision, so computer vision, with RGB cameras, is a vital source of semantic information from the environment. Sensors, such as LIDAR and RADAR, are also often utilized for these applications; however, cameras provide a higher spatial resolution and color information. The spatial frequency response (SFR), or sharpness of a camera, utilized in object detection systems must be sufficient to allow a detection algorithm to localize objects in the environment over its lifetime reliably. This study explores the relationship between object detection performance and SFR. Six state-of-the-art object detection models are evaluated with varying levels of lens defocus. A novel raw image dataset is created and utilized, containing pedestrians and cars over a range of distances up to 100-m from the sensor. Object detection performance for each defocused dataset is analyzed over a range of distances to determine the minimum SFR necessary in each case. Results show that the relationship between object detection performance and lens blur is much more complex than previous studies have found due to lens field curvature, chromatic aberration, and astigmatisms. We have found that smaller objects are disproportionately impacted by lens blur, and different object detection models have differing levels of robustness to lens blur
Applicability of Aeroacoustic Scaling Laws of Leading Edge Serrations for Rotating Applications
(2020)
Airborne volcanic ash particles are a known hazard to aviation. Currently, there are no means available to detect ash in flight as the particles are too fine (radii < 30 μm) for on-board radar detection and, even in good visibility, ash clouds are difficult or impossible to detect by eye. The economic cost and societal impact of the April/May 2010 Icelandic eruption of Eyjafjallajökull generated renewed interest in finding ways to identify airborne volcanic ash in order to keep airspace open and avoid aircraft groundings. We have designed and built a bi-spectral, fast-sampling, uncooled infrared camera device (AVOID) to examine its ability to detect volcanic ash from commercial jet aircraft at distances of more than 50 km ahead. Here we report results of an experiment conducted over the Atlantic Ocean, off the coast of France, confirming the ability of the device to detect and quantify volcanic ash in an artificial ash cloud created by dispersal of volcanic ash from a second aircraft. A third aircraft was used to measure the ash in situ using optical particle counters. The cloud was composed of very fine ash (mean radii ~10 μm) collected from Iceland immediately after the Eyjafjallajökull eruption and had a vertical thickness of ~200 m, a width of ~2 km and length of between 2 and 12 km. Concentrations of ~200 μg m(-3) were identified by AVOID at distances from ~20 km to ~70 km. For the first time, airborne remote detection of volcanic ash has been successfully demonstrated from a long-range flight test aircraft.
In den Möglichkeiten der Anschlusskommunikation online liegt ein hohes Demokratisierungspotential der Gesellschaft. Durch die Beteiligung möglichst vieler Bürger am politischen Diskurs kann ein neuer inklusiver und vielstimmiger Kommunikationsraum geschaffen werden, in dem die pluralen, vielschichtigen Stimmen der Gesellschaft über die persönlichen Kommunikationsnetzwerke der Einzelnen hinaus in den Austausch treten und so Koorientierung ermöglicht wird. Doch in der Forschung gibt es unterschiedliche Deutungen, ob und inwieweit diese Potenziale eingelöst werden. Der vorliegende Beitrag analysiert basierend auf einer Onlinebefragung die Teilhabe an verschiedenen Formen der Anschlusskommunikation aus einer Milieuperspektive. Die Befunde zeigen, dass die Muster der Anschlusskommunikation sich mit den Ergebnissen der sonstigen Kommunikationspraktiken in den politisch-kommunikativen Milieus decken. Ein politisch selbstbewusstes, engagiertes und informiertes Milieu nutzt besonders die proaktiven Möglichkeiten der Anschlusskommunikation, um Meinungen zu debattieren und auszutauschen. Ein sich in der kommunikativen Teilhabe zurückhaltendes Milieu partizipiert in ebenso geringem Maße an der Anschlusskommunikation und koppelt sich so von einem integrierten Kommunikationsraum ab. Sich abschottende Milieus legen einen starken Fokus auf reaktive Formen der Anschlusskommunikation, die zur permanenten Affirmation eigener Ansichten genutzt werden. Diese unterschiedliche Nutzung trägt dazu bei, dass gesellschaftliche Spaltungstendenzen eher bestärkt statt reduziert werden.
Der Beitrag stellt am Beispiel von studentischen Projekt- und Praxisarbeiten aus den bibliothekswissenschaftlichen Studiengängen der TH Köln Möglichkeiten der Erstellung von E-Learning-Angeboten vor, die sich in kurzer Zeit und ohne finanzielles Budget realisieren lassen. Der Fokus liegt dabei auf unkonventionellen Darstellungsformen wie bspw. Comic-artigen Animationsfilmen oder der Präsentation bibliothekarischer Inhalte nach dem Modell von „Sommers Weltliteratur“. Der Beitrag möchte Bibliotheken dazu anregen, im Kontext des E-Learning mit neuen Formaten zu experimentieren, die dazu beitragen können, die Attraktivität der bibliothekarischen Angebote zu erhöhen und die sich gleichzeitig mit geringem zeitlichem und finanziellem Aufwand realisieren lassen.
Building context-aware applications is an already widely researched topic. It is our belief that context awareness has the potential to supplement the Internet of Things, when a suitable methodology including supporting tools will ease the development of context-aware applications. We believe that a meta-model based approach can be key to achieving this goal. In this paper, we present our meta-model based methodology, which allows us to define and build application-specific context models and the integration of sensor data without any programming. We describe how that methodology is applied with the implementation of a relatively simple context-aware COVID-safe navigation app. The outcome showed that programmers with no experience in context-awareness were able to understand the concepts easily and were able to effectively use it after receiving a short training. Therefore, context-awareness is able to be implemented within a short amount of time. We conclude that this can also be the case for the development of other context-aware applications, which have the same context-awareness characteristics. We have also identified further optimization potential, which we will discuss at the conclusion of this article.
In the context of using renewable energies and recycling climate-changing gases, methanation of CO2 provides one possibility. However, volatile availability of renewable energies for hydrogen production and fluctuating CO2streams from different sources lead to enhanced demand in investigating the influence of dynamic process operation on the catalyst performance, including detailed kinetic characterization. Reliable kinetic measurements require isothermal temperature control and absence of macrokinetic diffusion limitations. Both were investigated in this work while the determination of steady-state kinetic parameters is part of ongoing studies. Furthermore, a detailed analysis with respect to the long-term-stability of the nickel-based catalyst was performed
Computational investigation of hemodynamics in hardshell venous reservoirs: A comparative study
(2019)
Extracorporeal circulation using heart‐lung‐machines is associated with a profound activation of corpuscular and plasmatic components of circulating blood, which can also lead to deleterious events such as systemic inflammatory response and hemolysis. Individual components used to install the extracorporeal circulation have an impact on the level of activation, most predominantly membrane oxygenators and hardshell venous reservoirs as used in extracorporeal systems. The blood flows in two different hardshell reservoirs are computationally investigated. A special emphasis is placed on the prediction of an onset of transition and turbulence generation. Reynolds‐averaged numerical simulations (RANS) based on a transitional turbulence model, as well as large eddy simulations (LES) are applied to achieve an accurate prediction. In the LES analysis, the non‐Newtonian behavior of the blood is considered via the Carreau model. Blood damage potential is quantified applying the Modified Index of Hemolysis (MIH) based on the predicted flow fields. The results indicate that the flows in both reservoirs remain predominantly laminar. For one of the reservoirs, considerable turbulence generation is observed near the exit site, caused by the specific design for the connection with the drainage tube. This difference causes the MIH of this reservoir to be nearly twice as large as compared to the alternative design. However, a substantial improvement of these performance criteria can be expected by a local geometry modification.
Actin filaments are conductive to ionic currents, mechanical and voltage solitons. These travelling localisations can be utilised to generate computing circuits from actin networks. The propagation of localisations on a single actin filament is experimentally unfeasible to control. Therefore, we consider excitation waves propagating on bundles of actin filaments. In computational experiments with a two-dimensional slice of an actin bundle network we show that by using an arbitrary arrangement of electrodes, it is possible to implement two-inputs-one-output circuits.
The links between innovativeness as a driver of economic performance, and the determinants of innovativeness have been investigated by management scholars and economists for decades, focusing mostly on “hard factors” as investment in research and development, or education. Focusing on a relatively neglected, but in times of globalization even more important aspect, the infuence of cultural characteristics on innovativeness, we apply diferent econometric models to test for links between cultural tightness and looseness on the one hand, and national innovativeness on the other hand. We fnd that cultural tightness—in the sense of homogenous and intolerant societies—has a negative link to national innovativeness, while cultural looseness—in the sense of tolerant and diverse societies—displays a positive link to national innovativeness.
Dandyismus und Popkultur
(2013)
This paper deals with the design of a micro-scale ORC plant for teaching and research including the development of an automated control concept. The aim is to provide a safe and environmentally acceptable micro-scale heat engine, which can be developed, implemented and used in university labs for the education of students as well as for small research projects. The test rig allows the support of several learning outcomes on a multi-disciplinary level particularly for the implementation and simulation of small power systems. Special attention was given to the organic working fluid characteristics and its selection process. In addition to the above-mentioned performance goals, favourable safety properties and low global warming potential were decisive in the selection of the novel organic fluid called 3M™ Novec™ 649. The performance and the fluid behaviour of Novec 649 in a micro-scale power cycle are of major interest and the research goal for the test rig presented in this paper. Due to the expected power output of 1 kW, a scroll expander was chosen as the generator drive for the micro plant. In order to design the major parts of the ORC, the thermodynamic simulation software EBSILON®Professional was used. The supply temperature was set to 140 °C. As a result of the simulation, feasible expander inlet pressures spread from 5.5 bar to 8.5 bar. This leads to thermal efficiencies of the ORC in the order of 5 %. Adding a recuperator to the cycle system decreases the operating pressure range but in the end, the thermal efficiency can be increased by 1.5 %-points up to 6.2 %. Finally, an automated control concept is introduced, where the pump is controlled via the fill level measurement system.
Poor young people more often face health difficulties, (learning) disabilities, and are overrepresented in special schools. Consequently, youth from poor households disproportionately frequently participate in disability‐specific programs aiming to improve their educational levels and labor market opportunities. They face a double burden of disability and poverty. In our study, we look at poor and non‐poor youth with disabilities (YPWD) who participate in vocational rehabilitation (VR) and whether VR helps them (a) in transitioning into employment and (b) in leaving poverty. We examine the association between the receipt of initial basic income support (BIS) as a poverty indicator, later labor market outcomes, and earned vocational qualification using administrative data. We make use of a sample of all persons accepted for VR in 2010 (N = 36,645). We employ logit models on VR attendees’ labor market outcomes three and five years after being accepted for VR as well as on their earned vocational qualifications. Beside initial poverty status, we control for educational level, type, and degree of disability and program pattern during the VR process. Our findings show that YPWD from poor households have a decreased likelihood of a vocational certificate and employment. Additionally, they are more likely to receive BIS than young people not from poor households and thus more likely to remain poor. In conclusion, VR seems to support poor YPWD less in their school‐to‐work transitions. Thus, disability‐specific programs should be more tailored to the social situations of participants, and counsellors should be more sensitive to their social backgrounds.
With the increasing capabilities of machine learning systems and their potential use in safety-critical systems, ensuring high-quality data is becoming increasingly important. In this paper, we present a novel approach for the assurance of data quality. For this purpose, the mathematical basics are first discussed and the approach is presented using multiple examples. This results in the detection of data points with potentially harmful properties for the use in safety-critical systems.
eFood in Deutschland
(2015)
Im Vergleich zu „Pionierbranchen“ wie Mode oder Medien steht der Online-Handel mit Lebensmitteln erst am Anfang. Dabei kann dieser zu einem Wettbewerbsvorteil werden – wenn der Handel es richtig angeht. Auf der anderen Seite steht das Risiko einer strategischen Falle, d.h. es wird unter Umständen aufgrund der Widerstände beim Verbraucher nur ein Nischenmarkt bedient, der eine geringe Profitabilität aufweist. Im Spannungsfeld „Marktpotenzial auf Handelsseite“ vs. „Zurückhaltung beim Verbraucher“ rücken dabei Fragen der Kommunikationspolitik im Online-Lebensmittelhandel in den Fokus. Für eine erfolgreiche Umsetzung stellt eine eindeutige Typologie eine notwendige Basis dar, um die konkreten Bedürfnisse potenzieller Konsumenten anzusprechen. Ein Engagement im eFood-Bereich ist daher als Investition in die zukünftige Entwicklung der Märkte und ihrer Zielgruppen zu betrachten. Although online trading in the food sector is still in early stages, it may become a competitive edge – if retailers go about it the right way. On the other hand, due to consumer resistance, there is the risk of serving only a niche market, which cannot be maintained in terms of profitability. Therefore, a stronger focus on communication policies is needed. Engaging in the eFood sector finally has to be seen as an important investment into future markets and their target groups. Keywords: online lebensmittelhandel, lieferfenster, informationszeitalter, face to the customer
Der Beitrag entwickelt anhand zahlreicher Beispiele rechtsterroristischer Gewalt eine Systematisierung instrumenteller Zielsetzungen rechtsterroristischen Handelns. Dabei ruft er zunächst als zentrale weltanschauliche Referenz den völkischen Nationalismus auf, dem biopolitische Paradigmen inhärent sind, denen mittels rechtsterroristischer Gewalt Geltung verschafft werden soll. Dieses ist für eine Vielzahl rechtsterroristischer Gewalttaten zentral, denen es um die Aufrechterhaltung rassistischer, sexistischer und heteronormativer Gesellschaftsverhältnisse geht. Regelmäßig ist solche Gewalt auch als Botschaftsverbrechen zu verstehen, wobei ganz unterschiedliche Modi der Kommunikation beobachtbar sind. Rechtsterroristische Gewalt – sofern sie nicht parastaatlich verfasst ist – hat nicht die direkte Schwächung der Kampffähigkeit des Gegners zum Ziel, sondern zielt auf Bestrafung, Einschüchterung und Vertreibung ausgewählter sozialer Gruppen und Individuen sowie in manchen Fällen auf das strategische Moment der Zuspitzung gesellschaftlicher Konflikte, wie im abschließenden Teil des Beitrages an zahlreichen Beispielen gezeigt wird.
Despite their overwhelming complexity, living cells display a high degree of internal mechanical and functional organization which can largely be attributed to the intracellular biopolymer scaffold, the cytoskeleton. Being a very complex system far from thermodynamic equilibrium, the cytoskeleton's ability to organize is at the same time challenging and fascinating. The extensive amounts of frequently interacting cellular building blocks and their inherent multifunctionality permits highly adaptive behavior and obstructs a purely reductionist approach. Nevertheless (and despite the field's relative novelty), the physics approach has already proved to be extremely successful in revealing very fundamental concepts of cytoskeleton organization and behavior. This review aims at introducing the physics of the cytoskeleton ranging from single biopolymer filaments to multicellular organisms. Throughout this wide range of phenomena, the focus is set on the intertwined nature of the different physical scales (levels of complexity) that give rise to numerous emergent properties by means of self-organization or self-assembly.
Kompetenzen auf dem Gebiet der Datenbanken gehören zum Pflichtbereich der Informatik. Das Angebot an Lehrbüchern, Vorlesungsformaten und Tools lässt sich jedoch für Lehrende oft nur eingeschränkt in die eigene Lehre integrieren. In diesem Aufsatz schildern wir unsere Erfahrungen in der Nutzung (frei) verfügbarer und der Entwicklung eigener digitaler Inhalte für grundlegende Datenbankveranstaltungen. Die Präferenzen der Studierenden werden mittels Nutzungsanalysen und Befragungen ermittelt. Wir stellen die Anforderungen auf, wie die nicht selten aufwendig herzustellenden digitalen Materialien von Lehrenden in ihre Lehr- und Lernumgebungen integriert werden können. Als konstruktive Antwort auf diese Herausforderung wird das Konzept EILD zur Entwicklung von Inhalten für die Lehre im Fach Datenbanken vorgestellt. Die Inhalte sollen in vielfältigen Lernszenarien eingesetzt werden können und mit einer Creative Commons (CC) Lizenzierung als OER (open educational resources) frei zur Verfügung stehen.
“Net Zero-Energy Building” has become a popular catchphrase to describe the synergy between energy-efficient building and renewable energy utilisation to achieve a balanced energy budget over an annual cycle. Taking into account the energy exchange with a grid overcomes the limitations of energy-autonomous buildings with the need for seasonal energy storage on-site. Although the expression, “Net Zero-Energy Building,” appears in many energy policy documents, a harmonised definition or a standardised balancing method is still lacking. This paper reports on the background and the various effects influencing the energy balance approach. After discussing the national energy code framework in Germany, a harmonised terminology and balancing procedure is proposed. The procedure takes not only the energy balance but also energy efficiency and load matching into account.
Rituals, such as gazing at faces, are common in body dysmorphic disorder (BDD) and appear in cognitive-behavioral models as a maintaining factor. Rituals are also common in obsessive-compulsive disorder (OCD). In contrast to OCD, the proposed associations between rituals and intrusive thoughts/appearance preoccupation have not been empirically investigated for BDD. We examined if the assumed effect of gazing rituals on attractiveness ratings exists and if it is associated with dissociation. In an experiment, we asked N = 65 non-clinical females to focus on the nose of a photographed face at pre- and post-test. In between, participants gazed at the nose of either the same (relevant gazing) or another face (irrelevant gazing). We found increasing dissociation after gazing in both conditions and a differentially stronger decrease of attractiveness ratings in the relevant gazing condition. Our findings support the hypothesized effect of gazing rituals on attractiveness evaluation in cognitive-behavioral models for BDD.
Geschäftsmodelle für das Internet der Dinge: Welche Geschäftsmodellinnovation passt zum Unternehmen?
(2020)
Many different cell types are able to migrate by formation of a thin actin-based cytoskeletal extension. Recently, it became evident that this extension consists of two distinct substructures, designated lamellipodium and lamellum, which differ significantly in their kinetic and kinematic properties as well as their biochemical composition. We developed a stochastic two-dimensional computer simulation that includes chemical reaction kinetics, G-actin diffusion, and filament transport to investigate the formation of growing actin networks in migrating cells. Model parameters were chosen based on experimental data or theoretical considerations. In this work, we demonstrate the system's ability to form two distinct networks by self-organization. We found a characteristic transition in mean filament length as well as a distinct maximum in depolymerization flux, both within the first 1-2 microm. The separation into two distinct substructures was found to be extremely robust with respect to initial conditions and variation of model parameters. We quantitatively investigated the complex interplay between ADF/cofilin and tropomyosin and propose a plausible mechanism that leads to spatial separation of, respectively, ADF/cofilin- or tropomyosin-dominated compartments. Tropomyosin was found to play an important role in stabilizing the lamellar actin network. Furthermore, the influence of filament severing and annealing on the network properties is explored, and simulation data are compared to existing experimental data.
A numerical study is carried out meticulously to scrutinize the impact of different shapes of chimneys like circular (outer dia, dc), convergent (outer dia, 0.5dc), divergent (outer dia, 1.5dc), sudden contraction (outer dia, 0.5dc), and sudden expansion (outer dia, 1.5dc) on the performance of an SCPP. Furthermore, the parametric impact with different chimney divergence angles (CDA, ϕ), and ground absorber slope angle (GSA, γ) on the SCPP performance is also scrutinized. Optimum divergence angle (ϕ=+0.75◦) enhances the power generation up to ~ 47% (76 kW) with a horizontal ground absorber surface. An increase or decrease in CDA lessens the power generation. With a sloped ground absorber angle γ=0.6◦, the gain in power generation is 60% (82 kW). The study of combination of ground sloped absorber (γ=0.6◦) and divergent chimney (ϕ=+0.75◦) shows enhancement of the power generation upto 80% (92 kW) more than the classical Manzaranes plant.
Impact of Renewable Energy Expansion to the Balancing Energy Demand of Differential Balancing Groups
(2018)
The research addresses the present situation on the German electricity market caused by variable renewable energy sources. The increasing number of households with photovoltaic and battery storage systems and their impacts require special attention. These systems change the traditional electricity customer from the sole electricity consumer to an electricity producer and consumer in one person. These so-called prosumers differ in their actual electricity demand from the initially estimated electricity demand with standard load profile. This discrepancy results in deviations within a differential balancing group. Thereby, the main finding of this research is a significant higher balancing energy demand with the expansion of photovoltaic and battery storage systems. Hence, the standard load profile is particularly not suitable for differential balancing groups with a high penetration of solar systems and still less suitable for groups with solar and battery storage systems
Individual addressing of trapped ions and coupling of motional and spin states using RF radiation
(2009)
Individual electrodynamically trapped and laser cooled ions are addressed in frequency space using radio-frequency radiation in the presence of a static magnetic field gradient. In addition, an interaction between motional and spin states induced by an rf field is demonstrated employing rf optical double resonance spectroscopy. These are two essential experimental steps towards realizing a novel concept for implementing quantum simulations and quantum computing with trapped ions.
Sound and music are well-studied aspects of the quality of experience in restaurants; the role of the room acoustical conditions, their influence on the visitors’ soundscape evaluation and their impact on the overall customer satisfaction in restaurants, however, has received less scientific attention. The present field study therefore investigated whether sound pressure level, reverberation time, and soundscape pleasantness can predict factors associated with overall restaurant quality. In total, 142 persons visiting 12 restaurants in Berlin rated relevant acoustical and non-acoustical factors associated with restaurant quality. Simultaneously, the A-weighted sound pressure level (LA,eq,15) was measured, and the reverberation time in the occupied state (T20,occ) was obtained by measurements performed in the unoccupied room and a subsequent calculation of the occupied condition according to DIN 18041. Results from linear mixed-effects models revealed that both the LA,eq,15 and T20,occ had a significant influence on soundscape pleasantness and eventfulness, whereby the effect of T20,occ was meditated by the LA,eq,15. Also, the LA,eq,15 as well as soundscape pleasantness were significant predictors of overall restaurant quality. A comprehensive structural equation model including both acoustical and non-acoustical factors, however, indicates that the effect of soundscape pleasantness on overall restaurant quality is mediated by the restaurant’s atmosphere. Our results support and extend previous findings which suggest that the acoustical design of restaurants involves a trade-off between comfort and liveliness, depending on the desired character of the place.
Kaufhaus-Punk auf youtube. Mediale Kontrolle zwischen Musiker und Fans am Beispiel von Jan Delay
(2012)
Magneto-hydrothermal triple-convection in a W-shaped porous cavity containing oxytactic bacteria
(2022)
Bioconvective heat and mass transport phenomena have recently been the subject of interest in diverse fields of applications pertaining to the motion of fluids and their thermophysical properties. The transport processes in a system involving triple convective phenomena, irregular geometry, and boundary conditions constitute a complex phenomenon. This work aims to explore the mixed thermo-bioconvection of magnetically susceptible fluid containing copper nanoparticles and oxytactic bacteria in a novel W-shaped porous cavity. The buoyant convention is generated due to the isothermal heating at the wavy bottom wall, whereas the mixed convection is induced due to the shearing motion of the top-cooled sliding wall. Furthermore, the bioconvection is induced due to the manifestation of oxytactic bacteria or organisms. The inclined sidewalls are insulated. The geometry is packed with water based Cu nanoparticle mixed porous structure, which is subjected to a magnetizing field acted horizontally. The complex transport equations are transformed into nondimensional forms, which are then computed using the finite volume-based developed code. The coupled triple-convective flow physics are explored for a wide range of involved controlling parameters, which could provide helpful insight to the system designer for its proper operation. The shape of geometry can be considered one of the important parameters to control the heat and mass transport phenomena. In general, the influence of amplitude (δ) is more compared to the waviness number (m) of the undulations. The magnitude of heat (Nu) and mass (Sh) transfer rate for the W-shaped cavity is high compared to conventional square and trapezoidal-shaped cavities. The output of the analysis could be very helpful for the designer for modeling devices operating on nanotechnology-based bioconvection, microbial fuel cells, and others.
Management des Innovationsportfolios: Portfolio-Matrizen zumManagement von Innovationsprojekten
(2021)
Men afflicted with hypogonadism have reduced fat-free mass and in some cases a loss in muscle strength. We hypothesize that muscle elasticity of the lower extremities differs between patients with hypogonadism and healthy controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0%, 5%, 10%, 15%, and 20% of the subject’s maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in applied force.