bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal power flow in multi‐terminal HVDC networks with embedded high‐power DC–DC converters for voltage matching and flexible DC transmission
Authors: Sayed Sawsan , Massoud Ahmed 
Published: June 2020

High‐power DC–DC converters are integrated into multi‐terminal high‐voltage DC (MTDC) networks, typically for voltage matching or flexible DC transmission. This study addresses droop‐controlled radial and mesh MTDC networks with transmission loss minimisation considering the impact of integrating a high‐power DC–DC converter. DC voltage droop control can achieve minimum power loss in radial MTDC transmission network by controlling the power‐sharing among the receiving nodes inversely proportional to their transmission line resistances. Updating the droop characteristics by an optimisation algorithm guarantees optimal power flow (OPF) during renewable source power generation fluctuation. Meanwhile, the mesh network DC voltage references can be updated by the OPF for transmission loss minimisation. This study presents the impact of incorporating a high‐power DC–DC converter at different system access lines of a radial MTDC network while targeting efficient power transfer and DC transmission loss minimisation. The effect of introducing a high‐power DC–DC converter on the droop characteristic settings during steady‐state operation in a radial MTDC network is investigated. Moreover, the impact of a high‐power DC–DC converter in mesh MTDC network with OPF operation is explored. To validate the presented concepts, the CIGRE B4 MTDC network is used as a benchmark system with a metaheuristic optimisation technique.
APEX CO observations towards the photodissociation region of RCW 120
Authors: Figueira M. , Zavagno A. , Bronfman L. , Russeil D. , Finger R. , Schuller F. 
Published: June 2020

Context. The edges of ionized (H II) regions are important sites for the formation of (high-mass) stars. Indeed, at least 30% of the Galactic high-mass-star formation is observed there. The radiative and compressive impact of the H II region could induce star formation at the border following different mechanisms such as the collect and collapse or the radiation-driven implosion (RDI) models and change their properties.
Aims. We aim to study the properties of two zones located in the photo dissociation region (PDR) of the Galactic H II region RCW 120 and discuss them as a function of the physical conditions and young star contents found in both clumps.
Methods. Using the APEX telescope, we mapped two regions of size 1.5′ × 1.5′ toward the most massive clump of RCW 120 hosting young massive sources and toward a clump showing a protrusion inside the H II region and hosting more evolved low-mass sources. The 12CO (J = 3−2), 13CO (J = 3−2) and C18O (J = 3−2) lines observed, together with Herschel data, are used to derive the properties and dynamics of these clumps. We discuss their relation with the hosted star formation.
Results. Assuming local thermodynamic equilibrium, the increase of velocity dispersion and Tex are found toward the center of the maps, where star-formation is observed with Herschel. Furthermore, both regions show supersonic Mach numbers (7 and 17 in average). No substantial information has been gathered about the impact of far ultraviolet radiation on C18O photodissociation at the edges of RCW 120. The fragmentation time needed for CC to be at work is equivalent to the dynamical age of RCW 120 and the properties of region B are in agreement with bright-rimmed clouds.
Conclusions. Although conclusions from this fragmentation model should be taken with caution, it strengthens the fact that, together with evidence of compression, CC might be at work at the edges of RCW 120. Additionally, the clump located at the eastern part of the PDR is a good candidate pre-existing clump where star-formation may be induced by the RDI mechanism.
Hot gas heating via magnetic arms in spiral galaxies
Authors: Weżgowiec M. , Ehle M. , Soida M. , Dettmar R.-J. , Beck R. , Urbanik M. 
Published: June 2020

Context. Reconnection heating has been considered as a potential source of the heating of the interstellar medium. In some galaxies, significant polarised radio emission has been found between the spiral arms. This emission has a form of “magnetic arms” that resembles the spiral structure of the galaxy. Reconnection effects could convert some of the energy of the turbulent magnetic field into the thermal energy of the surrounding medium, leaving more ordered magnetic fields, as is observed in the magnetic arms.
Aims. Sensitive radio and X-ray data for the grand-design spiral galaxy M 83 are used for a detailed analysis of the possible interactions of magnetic fields with hot gas, including a search for signatures of gas heating by magnetic reconnection effects.
Methods. Magnetic field strengths and energies derived from the radio emission are compared with the parameters of the hot gas calculated from the model fits to sensitive X-ray spectra of the hot gas emission.
Results. The available X-ray data allowed us to distinguish two thermal components in the halo of M 83. We found slightly higher average temperatures of the hot gas in the interarm regions, which results in higher energies per particle and is accompanied by a decrease in the energy density of the magnetic fields.
Conclusions. The observed differences in the energy budget between the spiral arms and the interarm regions suggest that, similar to the case of another spiral galaxy NGC 6946, we may be observing hints for gas heating by magnetic reconnection effects in the interarm regions. These effects, which act more efficiently on the turbulent component of the magnetic field, are expected to be stronger in the spiral arms. However, with the present data it is only possible to trace them in the interarm regions, where the star formation and the resulting turbulence is low.
Die neuromuskuläre Steuerung des Kaumechanismus und ihre
Bedeutung für die Kieferorthopädie
Authors: Fanghänel J. , Kirschneck C. 
Published: June 2020

ZusammenfassungDer Kaumechanismus gehört zu den kompliziertesten
neuromuskulären Leistungen des menschlichen Organismus. Er setzt ein
komplexes biologisches System mit einer optimalen multifaktoriellen
Steuerung voraus. Dabei ist eine effektive afferente und efferente
Innervation aller am Kaumechanismus beteiligten Strukturen sowie ihre
optimale Koordination im Sinne eines neuromuskulären Regelkreises
erforderlich. Der geregelte Ablauf der Kieferbewegungen wird durch neuronale
Regelzyklen unter der Kontrolle des Cortex cerebri und subkortikaler Areale
gesteuert. Dabei laufen alle Vorgänge der Steuerung in 3 Ebenen ab.
In der lokalen Ebene registrieren Rezeptoren die lokale Situation, in der
(sub)kortikalen Ebene werden Erregungen in Großhirnrinde und
Basalganglien verarbeitet sowie die (extra)pyramidalen Bahnen formiert.
Schließlich werden alle am Kauakt beteiligten Muskeln aktiviert.
Fehlerhafte oder traumatische Okklusionskontakte, wie sie im Rahmen von
Malokklusionen und bei erwachsenen Patienten im parodontal
vorgeschädigten Gebiss auftreten, haben dabei das Potenzial, den
neuromuskulären Regelkreis des stomatognathen Systems empfindlich zu
verändern und Fehlregulationen auszulösen. Eine genaue
Kenntnis der im Rahmen des Artikels besprochenen neuromuskulären
Steuerung des Kaumechanismus ist daher für den
Kieferorthopäden, der therapeutisch in dieses System eingreift, von
großer Bedeutung.
Erwachsenenbehandlung einer Klasse-II/1-Malokklusion
– Kombination aus skelettaler Verankerung und vollständig
individualisierter Lingualapparatur
Authors: Jacobs Collin , Jacobs Viviana , Wehrbein Heinrich , Roth Alexander 
Published: June 2020

ZusammenfassungDer vorliegende Fallbericht beschreibt die Therapie und das
Behandlungsergebnis eines erwachsenen Patienten mit
Angle-Klasse-II/1-Malokklusion durch eine vollständig
individualisierte Lingualapparatur (WIN, DW Lingual Systems, Bad Essen,
Germany) in Verbindung mit skelettaler Verankerung (Gaumenimplantat,
Orthosystem, Straumann, Basel, Switzerland). Die maximale Verankerung
ermöglichte eine En-masse-Distalisation der gesamten
Oberkieferdentition. Eine bilaterale Neutralokklusion mit physiologischem
Overjet und Overbite konnte erfolgreich eingestellt werden.
Ethical principles in machine learning and artificial intelligence: cases from the field and possible ways forward
Authors: Lo Piano Samuele 
Published: June 2020

AbstractDecision-making on numerous aspects of our daily lives is being outsourced to machine-learning (ML) algorithms and artificial intelligence (AI), motivated by speed and efficiency in the decision process. ML approaches—one of the typologies of algorithms underpinning artificial intelligence—are typically developed as black boxes. The implication is that ML code scripts are rarely scrutinised; interpretability is usually sacrificed in favour of usability and effectiveness. Room for improvement in practices associated with programme development have also been flagged along other dimensions, includinginter aliafairness, accuracy, accountability, and transparency. In this contribution, the production of guidelines and dedicated documents around these themes is discussed. The following applications ofAI-drivendecision-making are outlined: (a) risk assessment in the criminal justice system, and (b) autonomous vehicles, highlighting points of friction across ethical principles. Possible ways forward towards the implementation of governance on AI are finally examined.
The structure of abnormal extremals in a sub-Riemannian problem with growth vector
Authors: Sachkov Yu. L. , Sachkova E. F. 
Published: June 2020

Abstract
A left-invariant sub-Riemannian problem on a free nilpotent Lie group of step 4 with two generators is considered. The structure of abnormal extremals is described. These extremals are shown to define an abnormal foliation of the annihilator of the square of the distribution, which is given by the intersections of this annihilator with the leaves of the symplectic foliation of the Lie coalgebra. The question of abnormal trajectories being strictly/nonstrictly abnormal is investigated, their projection onto a plane of the distribution are described, estimates for the corank are given and examples of nonsmooth trajectories are constructed.
Bibliography: 14 titles.
On

-reflection of harmonic functions and

-approximation by harmonic polynomials
Authors: Paramonov P. V. , Fedorovskiy K. Yu. 
Published: June 2020

Abstract
We obtain several new sharp

-continuity conditions, both necessary and sufficient, for operators of harmonic reflection of functions over boundaries of simple Carathéodory domains in

. These results are based on a new criterion (also obtained in this paper) for

-continuity of the Poisson operator in the aforesaid domains. As corollaries, we give new sufficient conditions for

-approximability of functions by harmonic polynomials on boundaries of simple Carathéodory domains in

.
Bibliography: 17 titles.
Operator

-norms and their use
Authors: Shirokov M. E. 
Published: June 2020

Abstract
We consider a family of equivalent norms (called operator

-norms) on the algebra

of all bounded operators on a separable Hilbert space

induced by a positive densely defined operator

on

. By choosing different generating operators

we can obtain the operator

-norms producing different topologies, in particular, the strong operator topology on bounded subsets of

.
We obtain a generalised version of the Kretschmann-Schlingemann- Werner theorem, which shows that the Stinespring representation of completely positive linear maps is continuous with respect to the energy-constrained norm of complete boundedness on the set of completely positive linear maps and the operator

-norm on the set of Stinespring operators.
The operator

-norms induced by a positive operator

are well defined for linear operators relatively bounded with respect to the operator

, and the linear space of such operators equipped with any of these norms is a Banach space. We obtain explicit relations between operator

-norms and the standard characteristics of

-bounded operators. Operator

-norms allow us to obtain simple upper bounds and continuity bounds for some functions depending on

-bounded operators used in applications.
Bibliography: 29 titles.
Topological classification of integrable geodesic billiards on quadrics in three-dimensional Euclidean space
Authors: Belozerov G. V. 
Published: June 2020

Abstract
We consider geodesic billiards on quadrics in

. We consider the motion of a point mass inside a billiard table, that is, inside a domain lying on a quadric bounded by finitely many quadrics confocal with the given one and having angles at corner points of the boundary equal to

. According to the well-known Jacobi-Chasles theorem this problem turns out to be integrable. We introduce an equivalence relation on the set of billiard tables and prove a theorem on their classification. We present a complete classification of geodesic billiards on quadrics in

up to Liouville equivalence.
Bibliography: 19 titles.
Constructing artificial respiratory chain in polymer compartments: Insights into the interplay betweenbo3oxidase and the membrane
Authors: Marušič Nika , Otrin Lado , Zhao Ziliang , Lira Rafael B. , Kyrilis Fotis L. , Hamdi Farzad , Kastritis Panagiotis L. , Vidaković-Koch Tanja , Ivanov Ivan , Sundmacher Kai , Dimova Rumiana 
Published: June 2020

SignificanceAnalogous to phospholipids, some polymers assemble into vesicles and can mimic cellular membranes. Apart from enabling compartmentalization in the context of artificial cells, amphiphiles may serve as interface for proteins. However, complex transmembrane proteins were reconstituted in polymers with limited success so far. We functionally integrated the proton pumpbo3oxidase (part of the bacterial respiratory chain) in synthetic membranes made of PDMS-g-PEO and demonstrated lumen acidification. We provided mechanistic insights into the interplay between the protein and the (semi)synthetic membrane by measuring bending rigidity, lateral diffusion and disorder, proton permeability, and protein partitioning. Polymer and hybrid membranes displayed favorable properties for the construction of artificial cells such as membrane rearrangement, enhanced stability and fluidity, while keeping the compartments proton-tight.
Tight shoulders: A clinical, kinematic and strength comparison of symptomatic and asymptomatic male overhead athletes before and after stretching
Authors: Schwartz Cédric , Croisier Jean‐Louis , Brüls Olivier , Denoël Vincent , Forthomme Bénédicte 
Published: June 2020

AbstractA tightness of the posterior structures of the throwing shoulder has been hypothesised to be associated with injuries and pain because of alterations of the scapular kinematics and muscular imbalances. The aims of this study were to identify the clinical and biomechanical profile of symptomatic and asymptomatic overhead athletes with a tight shoulder and to evaluate the efficiency of a self‐applied stretching program. Twenty male overhead athletes were recruited. Half of them reported a painful shoulder at the beginning of the study. For four weeks, the volunteers performed daily stretching exercises. Before and after the stretching program, gleno‐humeral mobility, scapular kinematics, rotator muscles strength and pain were evaluated. Before stretching, the main difference between the groups was more impingement syndrome and rotator cuff tendon lesion positive tests in the symptomatic group (p < 0.027, effect size = 0.51). After the program, pain reported by the symptomatic volunteers was reduced by approximately 40% and the gleno‐humeral internal rotation bilateral difference was significantly reduced by 77.6% (p < 0.009, effect size = 0.84). In the symptomatic group, the scapula at rest was significantly more posteriorly tilted (p = 0.027, effect size = 0.69) after the stretching; a position that has been shown to limit the risk of impingement. The absence of significant differences of the profiles of the symptomatic and asymptomatic overhead athletes before stretching may indicate that the initiation of early prevention programs, including self‐applied stretching, should not rely solely on biomechanical and clinical parameters and might be recommended to all players with a tight shoulder.
High-quality vector vortex arrays by holographic and geometric phase control
Authors: Tang Yue , Perrie Walter , Schille Joerg , Loeschner Udo , Li Qianliang , Liu Dun , Edwardson Stuart P , Forbes Andrew , Dearden Geoff 
Published: June 2020

Abstract
Cylindrical vector vortex (CVV) beams are topical forms of structured light, and have been studied extensively as single beams, non-separable in two degrees of freedom: spatial mode and polarisation. Here we create arrays of CVV beams using a combination of dynamic phase controlled Dammann gratings and spin–orbit coupling through azimuthally varying geometric phase. We demonstrate control over the number, geometry and vectorness of the CVV arrays by simple adjustment of waveplates and computer generated holograms. To quantify the efficacy of our approach, we employ a recently proposed vector quality factor analysis, realising high quality vector beam arrays with purities in excess of 95%. Our approach is scalable in array size, robust (no interferometric beam combination) and allows for the on-demand creation of arbitrary vector beam arrays, crucial for applications that require multi-spot arrays, for example, in fast laser materials processing, multi-channel communication with spatial modes, and holographic optical traps, as well as in fundamental studies with vector optical lattices.
Radiometric characterization of a triggered narrow-bandwidth single-photon source and its use for the calibration of silicon single-photon avalanche detectors
Authors: Georgieva Hristina , López Marco , Hofer Helmuth , Christinck Justus , Rodiek Beatrice , Schnauber Peter , Kaganskiy Arsenty , Heindel Tobias , Rodt Sven , Reitzenstein Stephan , Kück Stefan 
Published: June 2020

Abstract
The traceability of measurements of the parameters characterizing single-photon sources, such as photon flux and optical power, paves the way towards their reliable comparison and quantitative evaluation. In this paper, we present an absolute measurement of the optical power of a single-photon source based on an InGaAs quantum dot under pulsed excitation with a calibrated single-photon avalanche diode (SPAD) detector. For this purpose, a single excitonic line of the quantum dot emission with a bandwidth below 0.1 nm was spectrally filtered by using two tilted interference filters. Since high count rates are essential for many metrological applications, we optimized the setup efficiency by combining high overall transmission of the optical components with a geometrical enhancement of the extraction efficiency of a single quantum dot by a monolithic microlens to reach photon fluxes up to

3.7
⋅

10
5

photons per second at the SPADs. A relative calibration of two SPAD detectors with a relative standard uncertainty of 0.7% was carried out and verified by the standard calibration method using an attenuated laser. Finally, an Allan deviation analysis was performed giving an optimal averaging time of 92 s for the photon flux.
Sources of off-target effects of vagus nerve stimulation using the helical clinical lead in domestic pigs
Authors: Nicolai Evan N , Settell Megan L , Knudsen Bruce E , McConico Andrea L , Gosink Brian A , Trevathan James K , Baumgart Ian W , Ross Erika K , Pelot Nicole A , Grill Warren M , Gustafson Kenneth J , Shoffstall Andrew J , Williams Justin C , Ludwig Kip A 
Published: June 2020

Abstract

Objective
Clinical data suggest that efficacious vagus nerve stimulation (VNS) is limited by side effects such as cough and dyspnea that have stimulation thresholds lower than those for therapeutic outcomes. VNS side effects are putatively caused by activation of nearby muscles within the neck, via direct muscle activation or activation of nerve fibers innervating those muscles. Our goal was to determine the thresholds at which various VNS-evoked effects occur in the domestic pig—an animal model with vagus anatomy similar to human—using the bipolar helical lead deployed clinically.

Approach
Intrafascicular electrodes were placed within the vagus nerve to record electroneurographic (ENG) responses, and needle electrodes were placed in the vagal-innervated neck muscles to record electromyographic (EMG) responses.

Main results
Contraction of the cricoarytenoid muscle occurred at low amplitudes (∼0.3 mA) and resulted from activation of motor nerve fibers in the cervical vagus trunk within the electrode cuff which bifurcate into the recurrent laryngeal branch of the vagus. At higher amplitudes (∼1.4 mA), contraction of the cricoarytenoid and cricothyroid muscles was generated by current leakage outside the cuff to activate motor nerve fibers running within the nearby superior laryngeal branch of the vagus. Activation of these muscles generated artifacts in the ENG recordings that may be mistaken for compound action potentials representing slowly conducting Aδ-, B-, and C-fibers.

Significance
Our data resolve conflicting reports of the stimulation amplitudes required for C-fiber activation in large animal studies (>10 mA) and human studies (<250 μA). After removing muscle-generated artifacts, ENG signals with post-stimulus latencies consistent with Aδ- and B-fibers occurred in only a small subset of animals, and these signals had similar thresholds to those that caused bradycardia. By identifying specific neuroanatomical pathways that cause off-target effects and characterizing the stimulation dose-response curves for on- and off-target effects, we hope to guide interpretation and optimization of clinical VNS.
Model of approximation of a velocity, vorticity and pressure in an incompressible fluid
Authors: Altamirano-Fernández A , Vergaño-Salazar J G , Duarte-Gandica I 
Published: June 2020

Abstract
Generally, the temporary discretization of the Navier-Stokes equations despise the convective term, and consider a boundary ∂Ω = . This paper introduces a Galerkin scheme designed to solve by means of the finite element method for the Oseen problem in three dimensions written in terms of speed, vorticity and pressure, in a viscous and incompressible fluid that flows through a porous medium, this problem is obtained from a temporary discretization of the Navier-Stokes equations and we consider a partitioned boundary ∂Ω = Γ1 ∪ Γ2 and disjoint, that is, the velocity is of the homogeneous Dirichlet type on Γ1, while the tangential velocity and pressure They are of the non-homogeneous Dirichlet type on Γ2. In the variational formulation the speed is completely decoupled, which allows you to approximate the vorticity and pressure independently. The speed is recovered from the vorticity and pressure. Galerkin’s scheme is based on Nédélec finite elements and continuous polynomials to pieces of the same order, for vorticity and pressure, respectively. Likewise, convergence rates are obtained for vorticity, speed and pressure in natural norms. Finally, a numerical example is provided that illustrates the behavior of the model.
Distribution model of toxic agents and runoff phenomenon in flat aquatic regions
Authors: Vergaño-Salazar J G , Meyer J F C A , Córdova-Lepe F , Duque Marín E 
Published: June 2020

Abstract
The study presents a model of distribution of toxic agents in flat aquatic regions such as lakes, lagoons, and coastal seas, two sources of pollution are modeled, one from the waste of industrial plants and another one, a product of the runoff phenomenon of the agricultural industry. Methodologically, a mathematical model based on the advection-diffusion equation is used, which allows knowing the concentration of the contaminant at all times in time for the given region. The problem system is described in its variational formulation in order to approximate its solution by the finite element method. The parameters used in the simulations are taken from secondary sources, in order to compare results and deferences in the same scenarios included in other models.