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See detailHybrid plasmonic nanostructures based on controlled integration of MoS2 flakes on metallic nanoholes
Garoli, Denis; Mosconi, Dario; Miele, Ermanno et al

in Nanoscale (2018), 10(36), 17105-17111

Here, we propose an easy and robust strategy for the versatile preparation of hybrid plasmonic nanopores by means of controlled deposition of single flakes of MoS2 directly on top of metallic holes. The ... [more ▼]

Here, we propose an easy and robust strategy for the versatile preparation of hybrid plasmonic nanopores by means of controlled deposition of single flakes of MoS2 directly on top of metallic holes. The device is realized on silicon nitride membranes and can be further refined by TEM or FIB milling to achieve the passing of molecules or nanometric particles through a pore. Importantly, we show that the plasmonic enhancement provided by the nanohole is strongly accumulated in the 2D nanopore, thus representing an ideal system for single-molecule sensing and sequencing in a flow-through configuration. Here, we also demonstrate that the prepared 2D material can be decorated with metallic nanoparticles that can couple their resonance with the nanopore resonance to further enhance the electromagnetic field confinement at the nanoscale level. This method can be applied to any gold nanopore with a high level of reproducibility and parallelization; hence, it can pave the way to the next generation of solid-state nanopores with plasmonic functionalities. Moreover, the controlled/ordered integration of 2D materials on plasmonic nanostructures opens a pathway towards new investigation of the following: enhanced light emission; strong coupling from plasmonic hybrid structures; hot electron generation; and sensors in general based on 2D materials. [less ▲]

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See detailA hybrid smoothed extended finite element/level set method for modeling equilibrium shapes of nano-inhomogeneities
Zhao, X.; Bordas, Stéphane UL; Qu, J.

in Computational Mechanics (2013)

Interfacial energy plays an important role in equilibrium morphologies of nanosized microstructures of solid materials due to the high interface-to-volume ratio, and can no longer be neglected as it does ... [more ▼]

Interfacial energy plays an important role in equilibrium morphologies of nanosized microstructures of solid materials due to the high interface-to-volume ratio, and can no longer be neglected as it does in conventional mechanics analysis. When designing nanodevices and to understand the behavior of materials at the nano-scale, this interfacial energy must therefore be taken into account. The present work develops an effective numerical approach by means of a hybrid smoothed extended finite element/level set method to model nanoscale inhomogeneities with interfacial energy effect, in which the finite element mesh can be completely independent of the interface geometry. The Gurtin-Murdoch surface elasticity model is used to account for the interface stress effect and the Wachspress interpolants are used for the first time to construct the shape functions in the smoothed extended finite element method. Selected numerical results are presented to study the accuracy and efficiency of the proposed method as well as the equilibrium shapes of misfit particles in elastic solids. The presented results compare very well with those obtained from theoretical solutions and experimental observations, and the computational efficiency of the method is shown to be superior to that of its most advanced competitor. © 2013 Springer-Verlag Berlin Heidelberg. [less ▲]

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See detailHybrid Societies: Challenges and Perspectives in the Design of Collective Behavior in Self-Organizing Systems
Hamann, Heiko; Khaluf, Yara; Botev, Jean UL et al

in Frontiers in Robotics and AI (2016), 3(14),

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See detailHybrid software and system development in practice: Waterfall, scrum, and beyond
Kuhrmann, Marco; Diebold, Philipp; Münch, Jürgen et al

in Proceedings of International Conference on Software and Systems Process (ICSSP) (2017, July)

Software and system development faces numerous challenges of rapidly changing markets. To address such challenges, companies and projects design and adopt specific development approaches by combining well ... [more ▼]

Software and system development faces numerous challenges of rapidly changing markets. To address such challenges, companies and projects design and adopt specific development approaches by combining well-structured comprehensive methods and flexible agile practices. Yet, the number of methods and practices is large, and available studies argue that the actual process composition is carried out in a fairly ad-hoc manner. The present paper reports on a survey on hybrid software development approaches. We study which approaches are used in practice, how different approaches are combined, and what contextual factors influence the use and combination of hybrid software development approaches. Our results from 69 study participants show a variety of development approaches used and combined in practice. We show that most combinations follow a pattern in which a traditional process model serves as framework in which several fine-grained (agile) practices are plugged in. We further show that hybrid software development approaches are independent from the company size and external triggers. We conclude that such approaches are the results of a natural process evolution, which is mainly driven by experience, learning, and pragmatism. [less ▲]

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See detailA hybrid T-Trefftz polygonal finite element for linear elasticity
Bhattacharjee, Kalyan; Natarajan, Sundararajan; Bordas, Stéphane UL

E-print/Working paper (2014)

In this paper, we construct hybrid T-Trefftz polygonal finite elements. The displacement field within the polygon is repre- sented by the homogeneous solution to the governing differential equation, also ... [more ▼]

In this paper, we construct hybrid T-Trefftz polygonal finite elements. The displacement field within the polygon is repre- sented by the homogeneous solution to the governing differential equation, also called as the T-complete set. On the boundary of the polygon, a conforming displacement field is independently defined to enforce continuity of the displacements across the element boundary. An optimal number of T-complete functions are chosen based on the number of nodes of the polygon and degrees of freedom per node. The stiffness matrix is computed by the hybrid formulation with auxiliary displacement frame. Results from the numerical studies presented for a few benchmark problems in the context of linear elasticity shows that the proposed method yield highly accurate results. [less ▲]

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See detailHybrid Transceivers Design for Large-Scale Antenna Arrays Using Majorization-Minimization Algorithms
Arora, Aakash UL; Tsinos, Christos UL; Shankar, Bhavani UL et al

in IEEE Transactions on Signal Processing (in press)

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See detailHybrid User Pairing for Spectral and Energy Efficiencies in Multiuser MISO-NOMA Networks with SWIPT
Nguyen, Toan-Van; Nguyen, van Dinh UL; Costa, Daniel Benevides Da et al

in IEEE Transactions on Communications (2020), 68(8), 4874-4890

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power ... [more ▼]

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power transfer. In this system, two information users with distinct channel conditions are optimally paired while energy users perform energy harvesting (EH) under non-linearity of the EH circuits. We consider the problem of jointly optimizing user pairing and power allocation to maximize the overall spectral efficiency (SE) and energy efficiency (EE) subject to userspecific quality-of-service and harvested power requirements. A new paradigm for the EE-EH trade-off is then proposed to achieve a good balance of network power consumption. Such design problems are formulated as the maximization of nonconcave functions subject to the class of mixed-integer non-convex constraints, which are very challenging to solve optimally. To address these challenges, we first relax binary pairing variables to be continuous and transform the design problems into equivalent non-convex ones, but with more tractable forms. We then develop low-complexity iterative algorithms to improve the objectives and converge to a local optimum by means of the inner approximation framework. Simulation results show the convergence of proposed algorithms and the SE and EE improvements of the proposed HUP scheme over state-of-the-art designs. In addition, the effects of key parameters such as the number of antennas and dynamic power at the BS, target data rates, and energy threshold, on the system performance are evaluated to show the effectiveness of the proposed schemes in balancing resource utilization. [less ▲]

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See detailHybride Praktiken. Methodologische Überlegungen zu einer erziehungswissenschaftlichen Ethnographie kindermedizinischer Vorsorgeuntersuchungen.
Bollig, Sabine UL; Kelle, Helga

in Hünersdorf, Bettina; Maeder, Christoph; Müller, Burkhard (Eds.) Ethnographie und Erziehungswissenschaft. Methodologische Reflexionen und empirische Annäherungen (2008)

Dieser Beitrag ist methodologischen Fragen nach dem Verhältnis von Ethnographie und Pädagogik gewidmet. Anhand eines empirischen Beispiels aus dem Forschungsprojekt „Kinderkörper in der Praxis“ wird für ... [more ▼]

Dieser Beitrag ist methodologischen Fragen nach dem Verhältnis von Ethnographie und Pädagogik gewidmet. Anhand eines empirischen Beispiels aus dem Forschungsprojekt „Kinderkörper in der Praxis“ wird für einen wissenssoziologisch informierten und praxisanalytisch orientierten Ansatz erziehungswissenschaftlicher Ethnographie plädiert, der sich nicht vorrangig über – ihrem Selbstverständnis nach – pädagogische Handlungsfelder definiert. Vielmehr versteht dieser Ansatz den Begriff des „Feldes“ im Sin-ne einer reflexiven Anthropologie auch und zunächst als einen rekursiven „Modus der Objektkonstruktion“ (Bourdieu/Wacquant 1996, S. 262). Solch ein heuristischer Feldbegriff in Verbindung mit einem formbezogenen Begriff von Pädagogik als Wissensordnung ermöglicht es, einerseits Konstruktionsbedingungen, Funktionen und Verfahrensweisen pädagogischer Praxisformen in vielfältigen Kontexten empirisch zu explorieren und gleichzeitig die je gewählten Forschungsfelder nicht vorgängig durch eine Fokussierung der Fragen auf „das Pädagogische“ weiter künstlich einzugrenzen. [less ▲]

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See detailHybridisation Schemes for Communication Satellite Payload Configuration Optimisation
Stathakis, Apostolos; Danoy, Grégoire UL; Talbi, El-Ghazali et al

in 17th European Conference on Applications of Evolutionary Computation (EvoApplications 2014) (2014, April)

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See detailHybridisierung von Berufs- und Hochschulbildung in Deutschland, Österreich und der Schweiz
Graf, Lukas UL

in Banscherus, Ulf; Engel, Ole; Mindt, Anne (Eds.) et al Differenzierung im Hochschulsystem: Nationale und internationale Entwicklungen und Herausforderungen (2015)

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See detailThe Hybridization of Vocational Training and Higher Education in Austria, Germany, and Switzerland
Graf, Lukas UL

Book published by Budrich UniPress (2013)

Austria, Germany, and Switzerland are increasingly relying on hybridization at the nexus of vocational training and higher education to increase permeability and reform their highly praised systems of ... [more ▼]

Austria, Germany, and Switzerland are increasingly relying on hybridization at the nexus of vocational training and higher education to increase permeability and reform their highly praised systems of collective skill formation. This historical and organizational institutionalist study compares these countries to trace the evolution of their skill regimes from the 1960s to today's era of Europeanization, focusing especially on the impact of the Bologna and Copenhagen processes. [less ▲]

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See detailHybridized enriched space-time finite element method for analysis of thin-walled structures immersed in generalized Newtonian fluids
Zilian, Andreas UL; Netuzhylov, H.

in Computers & Structures (2010), 88(21-22), 1265-1277

The paper addresses the numerical treatment of a specific class of fluid-structure interaction problems: flow-immersed thin structures undergoing considerable motion and deformation. The simultaneous ... [more ▼]

The paper addresses the numerical treatment of a specific class of fluid-structure interaction problems: flow-immersed thin structures undergoing considerable motion and deformation. The simultaneous solution procedure uses a mixed-hybrid velocity-based formulation of both fluid and structure discretized by a stabilized time-discontinuous space-time finite element method. The continuity at the interface is ensured by a localized mixed-hybrid interface method avoiding Lagrange multipliers and penalty approaches. The XFEM is utilized for enrichment of the approximation space of the fluid variables in order to represent non-smooth (discontinuous) solution features resulting from immersing a thin structure in a fluid. © 2010 Elsevier Ltd. All rights reserved. [less ▲]

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See detailHyCast-Podcast Discovery in Mobile Networks
Andronache, Adrian UL; Brust, Matthias R. UL; Rothkugel, Steffen UL

in Proceedings of the 3rd ACM Workshop on Wireless Multimedia Networking and Performance Modeling (WMuNeP '07) (2007)

Podcasts are a popular way to provide multimedia information about certain topics. A multitude of podcast servers exist in the Internet, allowing people to subscribe to them. Typically, podcasts are ... [more ▼]

Podcasts are a popular way to provide multimedia information about certain topics. A multitude of podcast servers exist in the Internet, allowing people to subscribe to them. Typically, podcasts are downloaded onto desktop computers and copied on mobile devices to be played while being on the move. In this paper, we extend the idea of podcasts, making them available in mobile network environments. In particular, HyCast does not rely on central podcast directories. Instead, HyCast also allows discovering, subscribing to, and downloading podcasts and episodes in the local neighborhood. For the dissemination of podcast information, we introduce and evaluate two different strategies. One is based on peer-to-peer communication between one-hop neighbors. The second one employs clustering to reduce the overhead of the podcast information dissemination. [less ▲]

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See detailHydra: a scalable proteomic search engine which utilizes the Hadoop distributed computing framework.
Lewis, Steven; Csordas, Attila; Killcoyne, Sarah UL et al

in BMC Bioinformatics (2012), 13

BACKGROUND: For shotgun mass spectrometry based proteomics the most computationally expensive step is in matching the spectra against an increasingly large database of sequences and their post ... [more ▼]

BACKGROUND: For shotgun mass spectrometry based proteomics the most computationally expensive step is in matching the spectra against an increasingly large database of sequences and their post-translational modifications with known masses. Each mass spectrometer can generate data at an astonishingly high rate, and the scope of what is searched for is continually increasing. Therefore solutions for improving our ability to perform these searches are needed. RESULTS: We present a sequence database search engine that is specifically designed to run efficiently on the Hadoop MapReduce distributed computing framework. The search engine implements the K-score algorithm, generating comparable output for the same input files as the original implementation. The scalability of the system is shown, and the architecture required for the development of such distributed processing is discussed. CONCLUSION: The software is scalable in its ability to handle a large peptide database, numerous modifications and large numbers of spectra. Performance scales with the number of processors in the cluster, allowing throughput to expand with the available resources. [less ▲]

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See detailHydrodynamic Analysis of Gas-Liquid-Liquid-Solid Reactors using the XDEM Numerical Approach
Baniasadi, Maryam UL; Peters, Bernhard UL; Baniasadi, Mehdi UL et al

in Canadian Journal of Chemical Engineering (2018)

Multiphase reactors are abundantly used in many industries. Among them, few reactors deal with four phases called gas-liquid-liquid-solid systems, which received less attention due to their complex ... [more ▼]

Multiphase reactors are abundantly used in many industries. Among them, few reactors deal with four phases called gas-liquid-liquid-solid systems, which received less attention due to their complex situation. Numerical study of such complex systems is not easy and requires loads of computational effort. In this study, a discrete-continuous numerical model known as eXtended discrete element method (XDEM) is proposed to investigate the hydrodynamic behaviour of fluid phases passing through the packed bed of solid particles. This model is applied to the dripping zone of a blast furnace. In this zone, two distinct liquid phases, namely liquid iron and slag, flow through a pile of coke particles while exchanging momentum. In this work, besides the solid-fluid and gas-liquid interactions, the liquid-liquid interactions are also studied and the phases' mutual effects are discussed. In addition, a sensitivity study on the slag viscosity is performed, which shows the importance of liquid phase properties on the system behaviour. The results evaluation shows that the liquid iron accelerates the downward flow of the slag and the slag decelerates the downward flow of the liquid iron phase due to the resistance force caused by their relative velocity. [less ▲]

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See detailHydrogen bonds and van der Waals forces in ice at ambient and high pressures
Santra, B.; Klimeš, J.; Alfè, D. et al

in Physical Review Letters (2011), 107(18),

The first principles methods, density-functional theory and quantum Monte Carlo, have been used to examine the balance between van der Waals (vdW) forces and hydrogen bonding in ambient and high-pressure ... [more ▼]

The first principles methods, density-functional theory and quantum Monte Carlo, have been used to examine the balance between van der Waals (vdW) forces and hydrogen bonding in ambient and high-pressure phases of ice. At higher pressure, the contribution to the lattice energy from vdW increases and that from hydrogen bonding decreases, leading vdW to have a substantial effect on the transition pressures between the crystalline ice phases. An important consequence, likely to be of relevance to molecular crystals in general, is that transition pressures obtained from density-functional theory exchange-correlation functionals which neglect vdW forces are greatly overestimated. © 2011 American Physical Society. [less ▲]

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See detailHydrogen peroxide-mediated killing of Caenorhabditis elegans by Streptococcus pyogenes.
Jansen, W. T. M.; Bolm, M.; Balling, Rudi UL et al

in Infection and Immunity (2002), 70(9), 5202-7

Caenorhabditis elegans is currently introduced as a new, facile, and cheap model organism to study the pathogenesis of gram-negative bacteria such as Pseudomonas aeruginosa and Salmonella enterica serovar ... [more ▼]

Caenorhabditis elegans is currently introduced as a new, facile, and cheap model organism to study the pathogenesis of gram-negative bacteria such as Pseudomonas aeruginosa and Salmonella enterica serovar Typhimurium. The mechanisms of killing involve either diffusible exotoxins or infection-like processes. Recently, it was shown that also some gram-positive bacteria kill C. elegans, although the precise mechanisms of killing remained open. We examined C. elegans as a pathogenesis model for the gram-positive bacterium Streptococcus pyogenes, a major human pathogen capable of causing a wide spectrum of diseases. We demonstrate that S. pyogenes kills C. elegans, both on solid and in liquid medium. Unlike P. aeruginosa and S. enterica serovar Typhimurium, the killing by S. pyogenes is solely mediated by hydrogen peroxide. Killing required live streptococci; the killing capacity depends on the amount of hydrogen peroxide produced, and killing can be inhibited by catalase. Major exotoxins of S. pyogenes are not involved in the killing process as confirmed by using specific toxin inhibitors and knockout mutants. Moreover, no accumulation of S. pyogenes in C. elegans is observed, which excludes the involvement of infection-like processes. Preliminary results show that S. pneumoniae can also kill C. elegans by hydrogen peroxide production. Hydrogen peroxide-mediated killing might represent a common mechanism by which gram-positive, catalase-negative pathogens kill C. elegans. [less ▲]

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See detailHydrogen-Bonded Networks Along and Bifurcation of the E-Pathway in Quinol:Fumarate Reductase
Herzog, Elena; Gu, Wei UL; Juhnke, Hanno D. et al

in Biophysical Journal (2012), 103(6), 1305-1314

The E-pathway of transmembrane proton transfer has been demonstrated previously to be essential for catalysis by the diheme-containing quinol:fumarate reductase (QFR) of Wolinella succinogenes. Two ... [more ▼]

The E-pathway of transmembrane proton transfer has been demonstrated previously to be essential for catalysis by the diheme-containing quinol:fumarate reductase (QFR) of Wolinella succinogenes. Two constituents of this pathway, Glu-C180 and heme bp ring C (b(D)-C-) propionate, have been validated experimentally. Here, we identify further constituents of the E-pathway by analysis of molecular dynamics simulations. The redox state of heme groups has a crucial effect on the connectivity patterns of mobile internal water molecules that can transiently support proton transfer from the b(D)-C-propionate to Glu-C180. The short H-bonding paths formed in the reduced states can lead to high proton conduction rates and thus provide a plausible explanation for the required opening of the E-pathway in reduced QFR. We found evidence that the b(D)-C-propionate group is the previously postulated branching point connecting proton transfer to the E-pathway from the quinol-oxidation site via interactions with the heme bp ligand His-C44. An essential functional role of His-C44 is supported experimentally by site-directed mutagenesis resulting in its replacement with Glu. Although the H44E variant enzyme retains both heme groups, it is unable to catalyze quinol oxidation. All results obtained are relevant to the QFR enzymes from the human pathogens Campylobacter jejuni and Helicobacter pylori. [less ▲]

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See detailHydrogeological effects on terrestrial gravity measurements
Van Camp, Michel; de Viron, Olivier; Dassargues, Alain et al

Scientific Conference (2019, December 10)

For the 20 last years, terrestrial and satellite gravity measurements have reached such a precision that they allow for identification of the signatures from water storage fluctuations. In particular ... [more ▼]

For the 20 last years, terrestrial and satellite gravity measurements have reached such a precision that they allow for identification of the signatures from water storage fluctuations. In particular, hydrogeological effects induce significant time-correlated signature in the gravity time series. Gravity response to rainfall is a complex function of the local geologic and climatic conditions, e.g., rock porosity, vegetation, evaporation, and runoff rates. The gravity signal combines contributions from many geophysical processes, source separation being a major challenge. At the local scale and short-term, the associated gravimetric signatures often exceed the tectonic and GIA effects, and monitoring gravity changes is a source of information on local groundwater mass balance, and contributes to model calibrations. Some aquifer main characteristics can then be inferred by combining continuous gravity, geophysical and hydrogeological measurements. In Membach, Belgium, a superconducting gravimeter has monitored gravity continuously for more than 24 years. This long time series, together with 300 repeated absolute gravity measurements and environmental monitoring, has provided valuable information on the instrumental, metrological, hydrogeological and geophysical points of view. This has allowed separating the signal sources and monitoring partial saturation dynamics in the unsaturated zone, convective precipitation and evapotranspiration at a scale of up to 1 km², for signals smaller than 1 nm/s², equivalent to 2.5 mm of water. Based on this experience, another superconducting gravimeter was installed in 2014 in the karst zone of Rochefort, Belgium. In a karst area, where the vadose zone is usually thicker than in other contexts, combining gravity measurements at the surface and inside accessible caves is a way to separate the contribution from the unsaturated zone lying between the two instruments, from the saturated zone underneath the cave, and the common mode effects from the atmosphere or other regional processes. Those experiments contribute to the assessment of the terrestrial hydrological cycle, which is a major challenge of the geosciences associated with key societal issues: availability of freshwater, mitigation of flood hazards, or measurement of evapotranspiration. [less ▲]

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