bluuebunny/crossref_metadata_2025 huggingface dataset:
Comment utiliser les tapis roulants pour la rééducation fonctionnelle
des chevaux
Authors: Gimenez Natacha
Published: July 2024

L’utilisation de tapis roulant permet de contrôler la vitesse et d’ajouter une pente, sur un sol ferme et constant. On peut donc contrôler la progression du travail, notamment lors de remise en activité.

Le tapis roulant induit des modifications de la locomotion (augmentation de la phase d’appui et de la phase postérieure de la foulée). Il faut veiller à la rectitude du cheval (ce qui nécessite la présence de deux personnes). L’affranchissement du poids du cavalier est particulièrement intéressant en cas de dorsalgie et d’affection incluant les boulets son appareil suspenseur. L’ajout d’une pente favorise la musculation du dos et de l’arrière-main en reportant le poids vers l’arrière, et doit, par conséquent, être utilisée avec précaution lors d’affections des postérieurs. Certains chevaux s’adaptent à la pente avec une extension lombaire exagérée : il faut surveiller la posture du cheval.

L’ajout d’eau permet de limiter l’impact du poids (réduction de 30 p. cent du poids effectif avec de l’eau au niveau de l’épaule).

La résistance induite par l’eau exige un effort supplémentaire qui permet de renforcer la musculature. La pression hydrostatique produit un effet de massage. Chaque individu modifie sa locomotion dans l’eau de manière différente : il convient de déterminer quel est le geste que l’on veut privilégier et identifier lors des premières séances quelles sont les hauteurs d’eau et vitesse qui permettent de l’obtenir. Le plus cohérent est de sélectionner la vitesse en fonction de l’individu, et la profondeur de l’eau en fonction du but recherché.

Il est essentiel de prescrire un protocole de remise en condition “cardio” lors du retour au travail monté, car contrairement aux idées reçues, le travail en aquatrainer, même avec des hauteurs d’eau conséquentes, ne permet pas d’atteindre les fréquences cardiaques obtenues sur le sol lors de travail monté ou attelé.
Résistance à l'insuline, hyperinsulinémie et fourbure
Authors: Jaillardon Laetitia , Stoetart Nicolas
Published: July 2024

La fourbure d’origine endocrinienne est l’une des plus fréquentes chez le cheval et le poney.

Les mécanismes physiopathologiques liant dérégulation de l’insuline et fourbure sont complexes et non totalement élucidés à ce jour, même si les études récentes s’accordent sur le rôle potentiel du récepteur à l’IGF1 (Insulin like Growth factor type 1) et sur le contexte inflammatoire local, longtemps écarté.
Une évaluation hormonale après un diagnostic de fourbure est indispensable, tant d’un point de vue pronostique que thérapeutique, même si aucun traitement spécifique n’est disponible aujourd’hui.
Comment utiliser la maréchalerie dans la prévention et la prise en charge des fourbures endocrinopathiques
Authors: Robert Mickaël
Published: July 2024

Comment utiliser la maréchalerie dans la prévention et la prise en charge des fourbures endocrinopathiques
Cet article présente les aspects biomécaniques et des techniques de maréchalerie utilisables préventivement, mais aussi une fois que l’animal présente une crise aiguë de fourbure endocrinienne, en insistant sur les bénéfices de l’élévation en talons et des supports de fourchette en complément du traitement médical.

Les aspects théoriques mais aussi pratiques du parage et du ferrage en phase chronique sont ensuite abordés avec pour objectifs de stabiliser la phalange distale dans la boite cornée, de contrôler la douleur du cheval et de stimuler la pousse de la corne.
Différents cas de figures sont abordés ainsi que les pronostics associés.
Comment effectuer le ferrage
Authors: Robert Mickaël
Published: July 2024

Dans cet article sont abordées les techniques de ferrage en cas de fourbure, en partant des positions théoriques des lignes de parage et du point de bascule. Les avantages des plaques, silicones et de différents types de fers ainsi que de leurs attributs sont présentés.
Enfin, des conseils sont apportés quant au suivi de ces cas et à la diminution progressives des attributs du fer quand l’état du cheval s’améliore.
Akzeptanzstudie zur elektronischen Patientenakte: Eine Befragung von
Versicherten und Leistungserbringern
Authors: Konopik Jens , Siebenbürger Maximilian , Schöffski Oliver , Blunck Dominik
Published: July 2024

Zielsetzung Die elektronische Patientenakte (ePA) steht seit dem 01.
Januar 2021 allen gesetzlich Versicherten zur Verfügung, jedoch bleibt ihre
Nutzung hinter den Erwartungen zurück. Diese Studie verfolgt das Ziel,
Einflussfaktoren auf die Akzeptanz und Nutzung der ePA zu identifizieren.

Methodik Es wurden Versicherte und Leistungserbringer mit Hilfe eines
Fragebogens befragt. Insgesamt wurden 143 Fragebögen in die Analyse aufgenommen
und ausgewertet.

Ergebnisse Beide Gruppen kritisieren die geringe
Sichtbarkeit in der Öffentlichkeit und insbesondere Versicherte fühlen sich
nicht ausreichend über die ePA aufgeklärt. Beide Gruppen sehen jedoch einen
Mehrwert in der ePA sowohl persönlich als auch aus gesamtgesellschaftlicher
Perspektive.

Schlussfolgerung Handlungsbedarf besteht insbesondere
hinsichtlich der Sichtbarkeit und Aufmerksamkeit der ePA in der öffentlichen
Wahrnehmung.
Alta tasa de complicaciones posoperatorias en fracturas balísticas de fémur distal
Authors: Arellano Sergio , González-Kusjanovic Nicolás , Anastasiadis Zoy , Guiloff Rodrigo , Edwards Diego , Schmidt-Hebbel Andrés , Vaisman Alex
Published: July 2024

Introducción Las fracturas de fémur están dentro de las lesiones más frecuentes por bala. Sin embargo, las fracturas de fémur distal por bala están escasamente estudiadas en la literatura.

Objetivo Presentar una cohorte de pacientes con fractura de fémur distal por bala tratados quirúrgicamente y analizar sus complicaciones.

Materiales y Métodos Estudio de cohorte retrospectiva, con pacientes operados por fractura de fémur distal por bala, en un hospital público de una zona con población vulnerable, de 2011 a 2015. Se constataron variables demográficas, días desde el ingreso a la cirugía definitiva, tiempo intraoperatorio, tipo de osteosíntesis definitiva, complicaciones y mortalidad al año.

Resultados En total, 39 pacientes cumplieron los criterios de inclusión; tenían promedio de edad de 30 (rango: 16–53) años, y 85% eran hombres. El promedio de latencia a osteosíntesis definitiva fue de 9,8 (rango 1–33) días. La tasa global de complicaciones fue de 25,64%, y la tasa de reintervenciones, de 23,08%. La principal complicación fue la infección (12,82%). No hubo factores estadísticamente significativos asociados a complicaciones. No hubo fallecidos al año de seguimiento.

Conclusión Los pacientes con fracturas de fémur distal por bala presentan una alta tasa de complicaciones, especialmente de infecciones, con una alta tasa de reintervenciones.

Nivel de evidencia: IV, estudio retrospectivo
Internet usage, access, and supervision among Ghanaian children: a cross-sectional study
Authors: Kyei-Arthur Frank , Kyei-Gyamfi Sylvester , Sarpong Solomon
Published: July 2024

Children’s access to and usage of the Internet has numerous benefits. However, their Internet access and use may pose risks to them, including cyberbullying, grooming, sexting, and exposure to dangerous materials. These risks may be exacerbated by inadequate supervision of children’s online activities. Therefore, this study examined the prevalence of Internet use, Internet access, and Internet use supervision among children aged 8–17 in Ghana. This study used secondary quantitative and qualitative data from the Ministry of Gender, Children, and Social Protection. The Statistical Package for the Social Sciences (SPSS) version 26 was used to analyze the quantitative data. In contrast, the qualitative data was analyzed using the constant comparison method with the aid of NVivo software version 10. The results showed that 90.5% of children had ever used the Internet. Smartphones (45.7), café facilities (21.7), and laptops/computers (21.6) were the most popular sources of Internet access. More than half of children (56.7) indicated they received little or no supervision when using their smartphones to access the Internet, which could lead to engagement in fraudulent activities, exposure to violent scenes online, and Internet addiction. The study found that most children had never used the Internet and received little or no supervision when accessing the Internet. It is, therefore, recommended that children need to be educated on the benefits and potential risks of excessive Internet use. Also, parents need to supervise and monitor their children’s Internet usage at home.
Introduction: anti-communism and the transnational transatlantic in the ‘long’ 1960s
Authors: Dubler Agnès , Großmann Johannes
Published: July 2024

This introductory essay for a special issue of the Journal for Transatlantic Studies on the transnational dimension of anti-communism in the Cold War provides a brief overview of the historical research on anti-communism to date. It presents anti-communism as a multifaceted phenomenon that should be studied not only as an ideological frame of reference and a political practice, but also as a social movement with an integrative, identity-forming function, and a high degree of mobilization and organization. In line with the contributions to the special issue, this essay argues that in the ‘long’ 1960s, (non-state) anti-communist actors and movements were forced to fundamentally adapt their thinking and actions in the face of Détente and global change. In order to keep anti-communism alive and to counter the policy of Détente, they intensified their transnational cooperation, which increasingly transcended the transatlantic level and took on a global dimension.
Design considerations for digital light processing bioprinters
Authors: Garciamendez-Mijares Carlos Ezio , Aguilar Francisco Javier , Hernandez Pavel , Kuang Xiao , Gonzalez Mauricio , Ortiz Vanessa , Riesgo Ricardo A. , Ruiz David S. Rendon , Rivera Victoria Abril Manjarrez , Rodriguez Juan Carlos , Mestre Francisco Lugo , Castillo Penelope Ceron , Perez Abraham , Cruz Lourdes Monserrat , Lim Khoon S. , Zhang Yu Shrike
Published: July 2024

With the rapid development and popularization of additive manufacturing, different technologies, including, but not limited to, extrusion-, droplet-, and vat-photopolymerization-based fabrication techniques, have emerged that have allowed tremendous progress in three-dimensional (3D) printing in the past decades. Bioprinting, typically using living cells and/or biomaterials conformed by different printing modalities, has produced functional tissues. As a subclass of vat-photopolymerization bioprinting, digital light processing (DLP) uses digitally controlled photomasks to selectively solidify liquid photocurable bioinks to construct complex physical objects in a layer-by-layer manner. DLP bioprinting presents unique advantages, including short printing times, relatively low manufacturing costs, and decently high resolutions, allowing users to achieve significant progress in the bioprinting of tissue-like complex structures. Nevertheless, the need to accommodate different materials while bioprinting and improve the printing performance has driven the rapid progress in DLP bioprinters, which requires multiple pieces of knowledge ranging from optics, electronics, software, and materials beyond the biological aspects. This raises the need for a comprehensive review to recapitulate the most important considerations in the design and assembly of DLP bioprinters. This review begins with analyzing unique considerations and specific examples in the hardware, including the resin vat, optical system, and electronics. In the software, the workflow is analyzed, including the parameters to be considered for the control of the bioprinter and the voxelizing/slicing algorithm. In addition, we briefly discuss the material requirements for DLP bioprinting. Then, we provide a section with best practices and maintenance of a do-it-yourself DLP bioprinter. Finally, we highlight the future outlooks of the DLP technology and their critical role in directing the future of bioprinting. The state-of-the-art progress in DLP bioprinter in this review will provide a set of knowledge for innovative DLP bioprinter designs.
Carbon-coated anodic aluminum oxide: Synthesis, characterization, and applications
Authors: Liu Hongyu , Pan Zheng-Ze , Itoh Tetsuji , Kyotani Takashi , Nishihara Hirotomo
Published: July 2024

Ordered porous carbon materials with regularly arranged pores and adjustable pore sizes have attracted significant attention due to their versatile applications across various fields. In this context, uniform carbon coating of anodic aluminum oxide (AAO) membranes is an effective approach to fabricating an ordered array of cylindrical carbonaceous nanopores with adjustable pore diameter and length. The resulting carbon-coated AAO (C/AAO) composite exhibits a meticulously ordered array of meso/macropores, devoid of inter-particle pores and resistance, setting it apart from conventional ordered porous carbons with powder forms. The pore dimensions of C/AAO can be precisely controlled over a wide range, and the carbon chemistry can be customized through heteroatom doping and chemical modifications, all without altering the pore structure. These inherent advantages position C/AAO as a highly promising material with broad application prospects. This review article provides a comprehensive overview of the synthesis and characterization of C/AAO and related materials, along with their diverse utilization in the fields of optics, field emission, gas sensing, energy storage, electrocatalyst support, and bionics. Furthermore, an outlook on the C/AAO materials is given at the end, highlighting their potential and associated challenges.
Ab initio density response and local field factor of warm dense hydrogen
Authors: Dornheim Tobias , Schwalbe Sebastian , Tolias Panagiotis , Böhme Maximilian P. , Moldabekov Zhandos A. , Vorberger Jan
Published: July 2024

We present quasi-exact ab initio path integral Monte Carlo (PIMC) results for the partial static density responses and local field factors of hydrogen in the warm dense matter regime, from solid density conditions to the strongly compressed case. The full dynamic treatment of electrons and protons on the same footing allows us to rigorously quantify both electronic and ionic exchange–correlation effects in the system, and to compare the results with those of earlier incomplete models such as the archetypal uniform electron gas or electrons in a fixed ion snapshot potential that do not take into account the interplay between the two constituents. The full electronic density response is highly sensitive to electronic localization around the ions, and our results constitute unambiguous predictions for upcoming X-ray Thomson scattering experiments with hydrogen jets and fusion plasmas. All PIMC results are made freely available and can be used directly for a gamut of applications, including inertial confinement fusion calculations and the modeling of dense astrophysical objects. Moreover, they constitute invaluable benchmark data for approximate but computationally less demanding approaches such as density functional theory or PIMC within the fixed-node approximation.
Unified theory for frequency combs in ring and Fabry–Perot quantum cascade lasers: An order-parameter equation approach
Authors: Silvestri Carlo , Brambilla Massimo , Bardella Paolo , Columbo Lorenzo Luigi
Published: July 2024

We present a unified model to describe the dynamics of optical frequency combs in quantum cascade lasers (QCLs), incorporating both ring and Fabry–Pérot (FP) cavity configurations. The model derives a modified complex Ginzburg–Landau equation (CGLE), leveraging an order parameter approach, and is capable of capturing the dynamics of both configurations, thus enabling a comparative analysis. This result demonstrates that FP QCLs, in addition to ring QCLs, belong to the same universality class of physical systems described by the CGLE, which includes, among others, systems in the fields of superconductivity and hydrodynamics. In the modified CGLE, a nonlinear integral term appears that is associated with the coupling between counterpropagating fields in the FP cavity and whose suppression yields the ring model, which is known to be properly described by a conventional CGLE. We show that this crucial term holds a key role in inhibiting the formation of harmonic frequency combs (HFCs), associated with multi-peaked localized structures, due to its anti-patterning effect. We provide support for a comprehensive campaign of numerical simulations in which we observe a higher occurrence of HFCs in the ring configuration compared to the FP case. Furthermore, the simulations demonstrate the model’s capability to reproduce experimental observations, including the coexistence of amplitude and frequency modulation, linear chirp, and typical dynamic scenarios observed in QCLs. Finally, we perform a linear stability analysis of the single-mode solution for the ring case, confirming its consistency with numerical simulations and highlighting its predictive power regarding the formation of harmonic combs.
Spinning dynamics of self-excited azimuthal acoustic modes in cavities
Authors: Shaaban Mahmoud , Noufal Rasha , Alziadeh Mohammed , Mohany Atef
Published: July 2024

The coupling between the shear layer separating between axisymmetric leading and trailing edges and the azimuthal modes of a cavity may result in self-excited spinning acoustic resonance. Notably, the spinning direction remains one of the less understood features of the coupled mode dynamics. In this work, compressible large eddy simulation is used to model the excitation of azimuthal acoustic modes in rectangular cavities. To verify the effect of aspect ratio on the resonant acoustic mode excitation, three cavities with aspect ratios W/H = 1.0, 0.95, and 0.90 are considered, all with the same shear layer length. While the square cross section cavity excited a pure spinning mode similar to that for a circular cavity, a small deviation from the square geometry in the coupled acoustic-flow fields leads to an attenuation of the acoustic mode amplitude. This attenuation results from a change in the phase characteristics, which impacts the spinning mode behavior. A slight side length mismatch drives a frequency difference between the two superimposed degenerate modes, resulting in a periodic reversal of the spinning direction. As the mismatch increases, the shear layer fails to excite one of the two modes, leading to the dominance of the other, and the aeroacoustic mode becomes fully stationary. More importantly, the shear layer follows the acoustic mode behavior such that the separation point changes its spinning direction accordingly. Consequently, the shape of the shear layer changes over time, resembling a clockwise helix, a counterclockwise helix, or crescent pairs closely following the acoustic mode.
Wake flow characteristics of small wind turbine models with single- and double-rotor arrangements: A wind tunnel study
Authors: Kumar Ravi , Siram Ojing , Saha Ujjwal K. , Sahoo Niranjan
Published: July 2024

In the multirotor system of a wind turbine, the overall power generation is greatly influenced by the placement and interaction of rotors in proximity. Thus, a great deal of study is needed to ascertain the integration strategy of small wind turbines. In this paper, the wake flow patterns have been investigated for two model wind turbines, viz., single-rotor and double-rotor arrangements operating at a low tip speed ratio. The model rotors composed of SG6043 airfoil have a similar configuration. In the single-rotor arrangement, the model rotor is placed at the center of the wind tunnel. While in the double-rotor arrangement, the model rotors are placed at an equal distance from the central line axis of the wind tunnel. To understand the wake propagation and interaction, experiments have been performed at various wind speed conditions such that the corresponding tip speed ratio is kept between 2.5 and 3. The study is, therefore, specifically focused on the wake characteristics of the rotors under low λ, and the assessment has been made within the near wake region. The span-wise and stream-wise assessments of the wake for the double rotor suggest a minimal velocity deficit close to the rotor plane and a higher deficit downstream contrary to the single-rotor configuration.
A five-dimensional Lorenz-type model near the temperature of maximum density
Authors: Rastegin A. E.
Published: July 2024

The current study formulates a convective model of the Lorenz type near the temperature of maximum density. The existence of this temperature actualizes water dynamics in temperate lakes. There is a conceptual interest in what this feature induces in Lorenz-type models. The consideration starts with the zero coefficient of thermal expansion. Other steps are like the famous Tritton's approach to derive the Lorenz model. This allows us to reduce difficulties with a selection of Galerkin functions. The analysis focuses on changes induced by zeroing the coefficient of thermal expansion. It results in a five-dimensional Lorenz-type model, whose equations are all nonlinear. The new model reiterates many features of the standard Lorenz model. The nontrivial critical points appear when the zero critical point becomes unstable. The nontrivial critical points correspond to two possible directions of fluid flow. Phase trajectories of the new model were studied numerically. The results are similar to the known five-dimensional extensions of the Lorenz model.
Compressible turbulent convection: The role of temperature-dependent thermal conductivity and dynamic viscosity
Authors: Panickacheril John John , Schumacher Jörg
Published: July 2024

The impact of variable material properties, such as temperature-dependent thermal conductivity and dynamical viscosity, on the dynamics of a fully compressible turbulent convection flow beyond the anelastic limit is studied in the present work by two series of three-dimensional direct numerical simulations in a layer of aspect ratio 4 with periodic boundary conditions in both horizontal directions. One simulation series is for a weakly stratified adiabatic background and the other one for a strongly stratified one. The Rayleigh number is 105 and the Prandtl number is 0.7 throughout this study. The temperature dependence of material parameters is imposed as a power law with an exponent β. It generates a superadiabaticity ε(z) that varies across the convection layer. Central statistical quantities of the flow, such as the mean superadiabatic temperature, temperature and density fluctuations, or turbulent Mach numbers are compared in the form of horizontal plane-time averaged profiles. It is found that the additional material parameter dependence causes systematic quantitative changes of all these quantities, but no qualitative ones. A growing temperature power law exponent β also enhances the turbulent momentum transfer in the weak stratification case by 40%, and it reduces the turbulent heat transfer by up to 50% in the strong stratification case.
Effect of structural, magnetic, magnetocaloric, and electrical polarization properties for multiferroic double perovskite Lu2CoCrO6 compound
Authors: Chatterjee Soma , Dutta Apurba , Das I.
Published: July 2024

We synthesized the Lu2CoCrO6 compound, multiferroic member of double perovskite system, by sol–gel method and then investigated the crystal structure, magnetization, magnetocaloric effect (MCE), and electrical polarization study. The analysis of powder x-ray diffraction pattern confirms that the monoclinic crystal structure with P21/n space group is better fitting for the Lu2CoCrO6 compound. Distribution between Co and Cr ions at the B-site is not perfectly ordered. Partial ordering between these B-site cations leads to a certain degree of disorder due to the presence of antisite defects and antiphase boundaries. These anti-site disorders (in the B-site) generate various fascinating magnetic phenomena. Although the temperature dependent inverse susceptibility plot shows predominant antiferromagnetic ground state in this system, simultaneously, a second order magnetic phase transition was observed from the Arrott plot. Moreover, the isothermal magnetization study confirms the coexistence of antiferromagnetic (AFM) and ferromagnetic (FM) phases below the transition temperature. The investigation of the magnetocaloric effect shows that the AFM phase of the system converts into the FM phases above critical field values. However, the breakdown of universal behavior of MCE in the paramagnetic region confirms the coexistence of the AFM phase as a secondary phase within the FM matrix. In addition, at lower temperatures, we observe a clear and well-defined ferroelectric hysteresis loop, suggesting ferroelectricity in the material. From these results, we conclude that Lu2CoCrO6 is a multiferroic material in which the coexisting magnetic and multiferroic phases appear to be correlated and weak magneto-electric coupling was also observed. Furthermore, our experimental results help to encourage basic fundamental as well as applied research on rare-earth and transition metal based double perovskite systems due to their complex exchange interaction and multiferroic behavior.
On the dipole moment distribution of rigid symmetric rotors
Authors: Schäfer Sascha , Heiles Sven , Schäfer Rolf
Published: July 2024

The properties of dipolar molecules in electric fields have been studied for a long time. Their description often requires extensive numerical simulations, and only a limited number of analytically solvable models are known so far. Here, we derive an expression for the dipole probability density function of polar rigid symmetric rotors in the limit of high rotational temperatures and low electric field strengths, starting from the moment sequence of the probability distribution. Deviations of the distribution due to the non-spherical shape of the rotors are discussed in detail. In addition, it is demonstrated that there is a general connection between the average dipole moment of a thermal ensemble of rigid rotors in the high-temperature limit and the average dipole moment of an ensemble adiabatically entering the electric field.
The temperature of maximum in density of aqueous solutions of nitrate and ammonium salts: Testing the Madrid-2019 force field
Authors: Blazquez S. , de Lucas M. , Vega C. , Troncoso J. , Gámez F.
Published: July 2024

The shift in the temperature of maximum in density (TMD) at room pressure of aqueous solutions of a set of five salts containing NO3− and/or NH4+ groups is studied both through experiments and through molecular dynamics simulations using the Madrid-2019 force field for ions and the TIP4P/2005 model for water. The experiments demonstrate the potential transferability and limitations of the Madrid-2019 force field for nitrate and ammonium ions recently developed by our group at different temperatures and add updated information to the reported datasets of TMDs for strong electrolytes. By using the Despretz law, individual ion contributions are extracted for predictive purposes from the experimental values of the shift in the TMD. Interesting findings for the behavior of the shift in the TMD in nitrate salts expose that this property might be particularly challenging for modelization approaches when dealing with polyatomic species.
Evaluation of the shadowgraph method for the determination of mutual and thermal diffusivities
Authors: Schmidt Patrick S. , Rausch Michael H. , Wu Wenchang , Fröba Andreas P.
Published: July 2024

The present work provides a systematic study on the influence of sample properties and experimental conditions on the reliable accessibility of Fick or mutual diffusion coefficients D11 and thermal diffusivities a in binary liquid mixtures using the shadowgraph method. For this, mixtures with varying magnitudes of the Soret coefficient ST and their optical contrast factors were studied at a temperature of 298.15 K and pressures between (0.1 and 0.65) MPa with varying magnitudes and orientations of the applied temperature and concentration gradients ∇T and ∇c. Experimental signals obtained in these investigations were analyzed with respect to the intensities of the signal contributions from non-equilibrium fluctuations (NEFs) in concentration and temperature, and the reliability of the determined D11 and a data was assessed by comparison to literature data. Larger signal intensities from NEFs and, therefore, a more reliable determination of diffusivities were given for sufficiently large magnitudes of ST, the optical contrast factors, and the applied ∇T and ∇c. At very small fluid layer thicknesses L ≤ 0.30 mm, the associated reduction of signal statistics outweighing the expected increase of signal intensities at larger magnitudes of ∇T and ∇c as well as the influence of confinement imposed limitations for the determination of diffusivities in some cases. Furthermore, an influence of the mixture composition on signal intensities from concentration-NEFs was identified, where too small mole fractions of one component can hinder the determination of D11 in mixtures with small magnitudes of the optical contrast factor (∂n/∂c)T,p.
Flow patterns and drag coefficients of dandelion pappus models consisting of two oppositely oriented filament layers
Authors: Fan Qing , Fu Lin-Tao , Huang Zong-Liu , Xin Cheng-Lai , Gu Hai-Hua
Published: July 2024

The architecture of real dandelion seeds is diverse. Previous studies have primarily focused on the flow patterns and drag coefficients of dandelion seeds with a pappus angle no greater than 180°, but have paid less attention to the cases of the pappus angle larger than 180°. This work therefore numerically investigated the flow patterns and drag coefficients of dandelion seeds with the pappus angle larger than 180° when the speed of incident flow is 0.2 m/s, using double-layered models consisting of two oppositely oriented filament layers. The simulated results were then compared to those obtained from single-layered models consisting of identical number of but leeward-oriented filaments (the pappus angle lower than 180°). It reveals that, either single-layered or double-layered models, the length (L) and width (W) of separated vortex rings increase, drag coefficients (CD) increase, but the shape index (L/W) and the relative location of separated vortex rings (zu) decrease, as the number of filaments increases. At a given filament number, L, W, and zu in double-layered models are smaller than those in single-layered models, but L/W and CD in double-layered models are larger than those in single-layered models, attributed to the windward-oriented filaments. In double-layered models, thanks to small difference in the drag force but significant difference in the projected area, CD is significantly higher when both windward-oriented and leeward-oriented filaments are installed at identical locations on the central disk's perimeter compared to cases where windward-oriented and leeward-oriented filaments are installed at different locations.
Tracking ultrafast non-adiabatic dissociation dynamics of the deuterated water dication molecule
Authors: Iskandar W. , Rescigno T. N. , Orel A. E. , Larsen K. A. , Severt T. , Streeter Z. L. , Jochim B. , Griffin B. , Call D. , Davis V. , McCurdy C. W. , Lucchese R. R. , Williams J. B. , Ben-Itzhak I. , Slaughter D. S. , Weber T.
Published: July 2024

We applied reaction microscopy to elucidate fast non-adiabatic dissociation dynamics of deuterated water molecules after direct photo-double ionization at 61 eV with synchrotron radiation. For the very rare D+ + O+ + D breakup channel, the particle momenta, angular, and energy distributions of electrons and ions, measured in coincidence, reveal distinct electronic dication states and their dissociation pathways via spin–orbit coupling and charge transfer at crossings and seams on the potential energy surfaces. Notably, we could distinguish between direct and fast sequential dissociation scenarios. For the latter case, our measurements reveal the geometry and orientation of the deuterated water molecule with respect to the polarization vector that leads to this rare 3-body molecular breakup channel. Aided by multi-reference configuration-interaction calculations, the dissociation dynamics could be traced on the relevant potential energy surfaces and particularly their crossings and seams. This approach also unraveled the ultrafast time scales governing these processes.
Persistent gravitational wave observables: nonlinearities in (non-)geodesic deviation
Authors: Grant Alexander M
Published: July 2024

The usual gravitational wave memory effect can be understood as a change in the separation of two initially comoving observers due to a burst of gravitational waves. Over the past few decades, a wide variety of other, ‘persistent’ observables which measure permanent effects on idealized detectors have been introduced, each probing distinct physical effects. These observables can be defined in (regions of) any spacetime where there exists a notion of radiation, such as perturbation theory off of a fixed background, nonlinear plane wave spacetimes, or asymptotically flat spacetimes. Many of the persistent observables defined in the literature have only been considered in asymptotically flat spacetimes, and the perturbative nature of such calculations has occasionally obscured deeper relationships between these observables that hold more generally. The goal of this paper is to show how these more general results arise, and to do so we focus on two observables related to the separation between two, potentially accelerated observers. The first is thecurve deviation, which is a natural generalization of the displacement memory, and also contains what this paper proposes to calldriftmemory (previously called ‘subleading displacement memory’) andballisticmemory. The second is a relative proper time shift that arises between the two observers, either at second order in their initial separation and relative velocity, or in the presence of relative acceleration. The results of this paper are, where appropriate, entirely non-perturbative in the curvature of spacetime, and so could be used beyond leading order in asymptotically flat spacetimes.
Advancements and challenges in strained group-IV-based optoelectronic materials stressed by ion beam treatment
Authors: Masteghin Mateus G , Murdin Benedict N , Duffy Dominic A , Clowes Steven K , Cox David C , Sweeney Stephen J , Webb Roger P
Published: July 2024

In this perspective article, we discuss the application of ion implantation to manipulate strain (by either neutralizing or inducing compressive or tensile states) in suspended thin films. Emphasizing the pressing need for a high-mobility silicon-compatible transistor or a direct bandgap group-IV semiconductor that is compatible with complementary metal–oxide–semiconductor technology, we underscore the distinctive features of different methods of ion beam-induced alteration of material morphology. The article examines the precautions needed during experimental procedures and data analysis and explores routes for potential scalable adoption by the semiconductor industry. Finally, we briefly discuss how this highly controllable strain-inducing technique can facilitate enhanced manipulation of impurity-based spin quantum bits (qubits).
Endless Dirac nodal lines and high mobility in kagome semimetal Ni3In2Se2 : a theoretical and experimental study
Authors: Kumar Pradhan Sanand , Pradhan Sharadnarayan , Mal Priyanath , Rambabu P , Lakhani Archana , Das Bipul , Lingam Chittari Bheema , Turpu G R , Das Pradip
Published: July 2024

Kagome-lattice crystal is crucial in quantum materials research, exhibiting unique transport properties due to its rich band structure and the presence of nodal lines and rings. Here, we investigate the electronic transport properties and perform first-principles calculations for Ni3In2Se2 kagome topological semimetal. First-principles calculations of the band structure without the inclusion of spin–orbit coupling (SOC) shows that three bands are crossing the Fermi level (E

F
), indicating the semi-metallic nature. With SOC, the band structure reveals a gap opening of the order of 10 meV. Z
2 index calculations suggest the topologically nontrivial natures (ν
0;

ν

1

ν

2

ν

3

) = (1;111) both without and with SOC. Our detailed calculations also indicate six endless Dirac nodal lines and two nodal rings with a π-Berry phase in the absence of SOC. The temperature-dependent resistivity is dominated by two scattering mechanisms: s-d interband scattering occurs below 50 K, while electron-phonon (e-p) scattering is observed above 50 K. The magnetoresistance (MR) curve aligns with the theory of extended Kohler’s rule, suggesting multiple scattering origins and temperature-dependent carrier densities. A maximum MR of 120% at 2 K and 9 T, with a maximum estimated mobility of approximately 3000 cm2V−1s−1 are observed. Ni3In2Se2 is an electron–hole compensated topological semimetal, as we have carrier density of electron (n

e
) and hole (n

h
) are

n

e

≈

n

h

, estimated from Hall effect data fitted to a two-band model. Consequently, there is an increase in the mobility of electrons and holes, leading to a higher carrier mobility and a comparatively higher MR. The quantum interference effect leading to the two dimensional (2D) weak antilocalization effect (−

σ

x
x

∝

ln

(
B
)

) manifests as the diffusion of nodal line fermions in the 2D poloidal plane and the associated encircling Berry flux of nodal-line fermions.
A fine-tuning prototypical network for few-shot cross-domain fault diagnosis
Authors: Zhong Jianhua , Gu Kairong , Jiang Haifeng , Liang Wei , Zhong Shuncong
Published: July 2024

With the continuous development of computer technology, deep learning has been widely used in fault diagnosis and achieved remarkable results. However, in actual production, the problem of insufficient fault samples and the difference in data domains caused by different working conditions seriously limit the improvement of model diagnosis ability. In recent years, meta-learning has attracted widespread attention from scholars as one of the main methods of few-shot learning. It can quickly adapt to new tasks by training on a small number of samples. A fine-tuning prototypical network is proposed on meta-learning methods to address the challenges of fault diagnosis under few-shot and cross-domain. Firstly, the shuffle attention is used to enhance the feature extraction ability of the network and suppress irrelevant features. Then, the support set of the target domain is split into two parts: pseudo support set and pseudo query set, which are used to fine-tune the prototypical network and improve the model generalization. Finally, experiments are conducted on three rotating equipment datasets to verify the method’s effectiveness.
Calculation of the inverse involute function and application to measurement over pins
Authors: Zhou Yixin , Wu Baisheng , Chen Zeyao , Zhong Congwen , Zhong Huixiang
Published: July 2024

Measurement over pins plays a crucial role in ensuring the quality of gear manufacturing, which requires the evolution of the inverse involute function. In this paper, an efficient algorithm for calculating the inverse involute function is proposed. Firstly, the initial approximate solution of the pressure angle near 0 rad is established by using Padé approximation and one step of Schröder iteration. Then, the involute equation is transformed into another form by introducing a variable transformation, and the initial approximate solution of the pressure angle near

π

/

2

rad is constructed by using the same method. A piecewise initial approximate solution over the entire interval of expanded angles is obtained by combining these solutions. Again, the accuracy of the initial approximate solution can be significantly improved by using one step of Schröder iteration. A numerical example of a two-pin measurement is presented to demonstrate the superiority of our method over traditional iterative approaches. The algorithm is highly efficient and accurate, and is a useful tool for designers to accurately calculate gear systems.
An experimental apparatus to study the adsorption of water on proxies for spent nuclear fuel surfaces
Authors: Sasikumar Yadukrishnan , Nuttall William J , Mason Nigel J
Published: July 2024

This paper describes the design, construction and testing of an experimental apparatus capable of conducting high temperature adsorption isotherm analyses on large quantities of powder samples inside an ultra-high vacuum chamber. Data is obtained by dosing in fixed amounts of water vapor and measuring precise pressure changes using a high temperature capacitance manometer. The rig is designed to provide insight into the wetting of failed spent nuclear fuel (SNF) under conditions conventionally regarded as ‘dry’. Validation experiments are reported based on powder CeO2 (a non-radioactive surrogate for SNF) at 100 °C. It is planned that this and successor rigs can provide ever more direct experimental evidence to address a key policy–relevant problem.
Enhancing the reliability of deep learning-based head and neck tumour segmentation using uncertainty estimation with multi-modal images
Authors: Ren Jintao , Teuwen Jonas , Nijkamp Jasper , Rasmussen Mathis , Gouw Zeno , Grau Eriksen Jesper , Sonke Jan-Jakob , Korreman Stine
Published: July 2024

Objective. Deep learning shows promise in autosegmentation of head and neck cancer (HNC) primary tumours (GTV-T) and nodal metastases (GTV-N). However, errors such as including non-tumour regions or missing nodal metastases still occur. Conventional methods often make overconfident predictions, compromising reliability. Incorporating uncertainty estimation, which provides calibrated confidence intervals can address this issue. Our aim was to investigate the efficacy of various uncertainty estimation methods in improving segmentation reliability. We evaluated their confidence levels in voxel predictions and ability to reveal potential segmentation errors. Approach. We retrospectively collected data from 567 HNC patients with diverse cancer sites and multi-modality images (CT, PET, T1-, and T2-weighted MRI) along with their clinical GTV-T/N delineations. Using the nnUNet 3D segmentation pipeline, we compared seven uncertainty estimation methods, evaluating them based on segmentation accuracy (Dice similarity coefficient, DSC), confidence calibration (Expected Calibration Error, ECE), and their ability to reveal segmentation errors (Uncertainty-Error overlap using DSC, UE-DSC). Main results. Evaluated on the hold-out test dataset (n = 97), the median DSC scores for GTV-T and GTV-N segmentation across all uncertainty estimation methods had a narrow range, from 0.73 to 0.76 and 0.78 to 0.80, respectively. In contrast, the median ECE exhibited a wider range, from 0.30 to 0.12 for GTV-T and 0.25 to 0.09 for GTV-N. Similarly, the median UE-DSC also ranged broadly, from 0.21 to 0.38 for GTV-T and 0.22 to 0.36 for GTV-N. A probabilistic network—PhiSeg method consistently demonstrated the best performance in terms of ECE and UE-DSC. Significance. Our study highlights the importance of uncertainty estimation in enhancing the reliability of deep learning for autosegmentation of HNC GTV. The results show that while segmentation accuracy can be similar across methods, their reliability, measured by calibration error and uncertainty-error overlap, varies significantly. Used with visualisation maps, these methods may effectively pinpoint uncertainties and potential errors at the voxel level.
Improving CZTS/ZTO solar cell efficiency with inorganic BSF layers
Authors: Chargui Taoufik , Lmai Fatima , Al-Hattab Mohamed , Rahmani Khalid
Published: July 2024

Copper zinc tin sulfide (CZTS) thin-film solar cells have garnered significant attention in the solar energy sector. This study aims to enhance the performance of CZTS solar cells by replacing the conventional, toxic CdS buffer layer with

Z

n

1
−
x

S

n

x

O

(ZTO) for x = 0.2. Utilizing the one-dimensional solar cell capacitance simulator (SCAPS-1D) and informed by experimental data on the physical properties of the solar cell layers, we investigated the effects of thickness, doping density, and defect density of the CZTS absorber layer on the cell’s performance. Initially, an efficiency of 14.76% was achieved. To improve this efficiency, an inorganic back surface field (BSF) layer was incorporated to mitigate charge carrier recombination at the absorber/back contact metal interface. Various materials, including CuO,

C

u

2

O

, Mo

S

2

and Mo

S

e

2

, were evaluated as potential BSF layers. Comparative analysis indicated that the inclusion of the BSF layer significantly enhances the solar cell efficiency, achieving up to 27% with

C

u

2

O

as the BSF material. Furthermore, the study included an analysis of temperature effects and parasitic resistances to comprehensively assess the solar cell’s performance.
The nontrivial effects of annealing on superconducting properties of Nb single crystals
Authors: Datta Amlan , Joshi Kamal R , Berti Giulia , Ghimire Sunil , Goerdt Aidan , Tanatar Makariy A , Schlagel Deborah L , Besser Matthew F , Jing Dapeng , Kramer Matthew J , Iavarone Maria , Prozorov Ruslan
Published: July 2024

The effect of annealing on the superconducting properties of niobium single crystals was studied using optical, magnetic, and scanning tunneling microscopy (STM) methods. Pieces of the same crystal boule were studied before and after the annealing at 800 ∘C, 1400 ∘C, and near the melting point of niobium (2477 ∘C). The initial samples had a high hydrogen content and low-temperature imaging revealed large hydrides (hundreds of micrometers) appearing below 190 K. The formation of these large precipitates is already completely suppressed by annealing at 800 ∘C. However, the overall superconducting properties of the annealed samples did not improve and, in fact, worsened. In particular, the superconducting transition temperature decreased, the upper critical field increased, and the pinning strength increased. In the STM study, the sample was annealed initially at 400 ∘C, measured, annealed at 1700 ∘C, and measured again. The STM revealed a ‘dirty’ superconducting gap with a significant spatial variation in tunneling conductance after annealing at 400 ∘C. The clean gap was recovered after annealing at 1700 ∘C. This is likely due to oxygen redistribution near the surface, which is always covered by oxide layers in as-grown crystals. Our results indicate that vacuum annealing at least up to 1400 ∘C, while removing a large percentage of hydrogen, introduces additional nanosized defects, likely hydride precipitates, that act as efficient pair-breaking and pinning centers. The dimensionless scattering rate is estimated to have increased fromΓ=0.2to aboutΓ=0.4after annealing at 1400 ∘C. These results on single crystals differ drastically from those obtained in polycrystalline bulk niobium (i.e. cut from superconducting radio-frequency cavities), where annealing is known to have a significant positive effect that is attributed to the improvement of the crystalline structure masking the more subtle influence of the hydrides.
Soliton sheets of Bose–Einstein condensates in optical lattices
Authors: Wang Shu-Song , Zhang Su-Ying
Published: July 2024

Soliton sheets are observed in Bose–Einstein condensates in optical lattice which are formed by superposition of condensates occupying different single-particle states. These structures consist of one-dimensional stationary solitons distributed in the x-direction arranged continuously along the peaks of the optical lattice in the y-direction. Notably, the phase difference across the soliton sheets is periodic and varies linearly with y within each period. So, we refer to this configuration as a ‘soliton sheet’. A velocity difference in the y-component is observed between the two sides of the soliton sheets. Similar velocity distributions can be achieved by aligning an infinite number of isotropic vortices along the peaks of the optical lattice. And the soliton sheets are distinguished by their lack of dependence on phase singularities. This independence enables the formation of soliton sheets even in the absence of phase singularities, highlighting a unique aspect of this structure.