bluuebunny/crossref_metadata_2025_split huggingface dataset:
Source of the Fe Kα emission in T Tauri stars
Authors: Gómez de Castro Ana I. , Antonicci Anna , Carlos Vallejo Juan 
Published: May 2024

Context. T Tauri stars (TTSs) are magnetically active stars that accrete matter from the inner border of the surrounding accretion disk; plasma becomes trapped into the large-scale magnetic structures and falls onto the star, heating the surface through the so-called accretion shocks. The X-ray spectra of the TTSs show prominent Fe Kα fluorescence emission at 6.4 keV (hereafter, Fe Kα emission) that cannot be explained in a pure accretion scenario because its excitation requires significantly more energy than the maximum available through the well-constrained free-fall velocity. Neither can it be produced by the hot coronal plasma.
Aims. TTSs display all signs of magnetic activity, and magnetic reconnection events are expected to occur frequently. In these events, electrons may become accelerated to relativistic speeds, and their interaction with the environmental matter may result in Fe Kα emission. It is the aim of this work to evaluate the expected Fe Kα emission in the context of the TTS research and compare it with the actual Fe Kα measurements obtained during the flare detected while monitoring RY Tau with the XMM-Newton satellite.
Methods. The propagation of high-energy electrons in dense gas generates a cascade of secondary particles that results in an electron shower of random nature, whose evolution and radiative throughput was simulated in this work using the Monte Carlo code PENELOPE. A set of conditions representing the environment of the TTSs where these showers may impinge was taken into account to generate a grid of models that can aid the interpretation of the data.
Results. The simulations show that the electron beams produce a hot spot at the point of impact; strong Fe Kα emission and X-ray continuum radiation are produced by the spot. This emission is compatible with RY Tau observations.
Conclusions. The Fe Kα emission observed in TTSs could be produced by beams of relativistic electrons accelerated in magnetic reconnection events during flares.
Die Behandlung in zertifizierten Brustkrebszentren verbessert die Überlebenschancen von Patient*innen mit Brustkrebs
Authors: Schoffer Olaf , Wimberger Pauline , Gerken Michael , Bierbaum Veronika , Bobeth Christoph , Rößler Martin , Dröge Patrik , Ruhnke Thomas , Günster Christian , Kleihues-van Tol Kees , Link Theresa , Scharl Anton , Inwald Elisabeth C. , Kast Karin , Papathemelis Thomas , Ortmann Olaf , Klinkhammer-Schalke Monika , Schmitt Jochen 
Published: May 2024

ZusammenfassungZertifizierte Brustkrebszentren bieten spezifische Qualitätsstandards für die Struktur,
Diagnostik und Behandlungsverfahren, beispielsweise der Mammachirurgie, medikamentösen
Tumortherapie, Strahlentherapie und psychosozialen Unterstützung, mit dem Ziel, die
Behandlungsergebnisse für Brustkrebspatient*innen zu verbessern. Die Frage ist jedoch, ob
Patient*innen mit primärem Brustkrebs ein längeres Überleben haben, wenn sie in einem
zertifizierten Brustkrebszentrum behandelt werden, im Vergleich zur Behandlung außerhalb
dieser Zentren.Wir verwendeten patient*innenspezifische Informationen (demografische Merkmale,
Diagnosen, Behandlungen) aus den Daten der gesetzlichen Krankenversicherung (GKV) und
klinischer Krebsregister (KKR) für den Zeitraum 2009–2017 sowie Krankenhausmerkmale aus den
Standardisierten Qualitätsberichten. Wir untersuchten mittels multivariabler
Cox-Regressionen Unterschiede im Überleben zwischen Patient*innen, die in Kliniken mit und
ohne Zertifizierung als Brustkrebszentrum der Deutschen Krebsgesellschaft (DKG) behandelt
wurden.Die Stichprobe umfasste 143720 (GKV-Daten) bzw. 59780 (KKR-Daten) Patient*innen mit
Brustkrebs, die in 1010 Krankenhäusern behandelt wurden (280 DKG-zertifiziert, 730 nicht
DKG-zertifiziert). 63,5% (GKV-Daten) bzw. 66,7% (KKR-Daten) der Patient*innen wurden in
DKG-zertifizierten Brustkrebszentren behandelt. Cox-Regressionen für das Gesamtüberleben,
bei denen Patienten- und Krankenhausmerkmale berücksichtigt wurden, ergaben ein signifikant
niedrigeres Sterberisiko für Patient*innen, die in DKG-zertifizierten Brustkrebszentren
behandelt wurden (GKV-Daten: HR = 0,77, 95%-KI = 0,74–0,81; KKR-Daten: HR = 0,88,
95%-KI = 0,85–0,92). Dieses Ergebnis blieb auch in mehreren Sensitivitätsanalysen stabil,
einschließlich stratifizierter Schätzungen für Untergruppen von Patient*innen und
Krankenhäusern. Für das rezidivfreie Überleben war der Effekt noch stärker ausgeprägt
(KKR-Daten: HR = 0,78, 95%-KI = 0,74–0,82).Patient*innen, die von einem interdisziplinären Team in einem DKG-zertifizierten
Brustkrebszentrum behandelt wurden, wiesen ein deutlich und statistisch signifikant
verbessertes Überleben auf. Die Zertifizierung ist somit ein wirksames Mittel zur
Verbesserung der Versorgungsqualität, und es sollten mehr Patient*innen in zertifizierten
Brustkrebszentren behandelt werden.
Homeopathy as a Means to Improve Quality of Life
Authors: Fujino Fernanda Maria Simões da Costa , Ribeiro Ana Paula , Armond Jane de Eston , Souza Patrícia Colombo de 
Published: May 2024

AbstractQuality of life is a fundamental aspect of good health and differs from person to person, highlighting the importance of individualisation, which is one of the principles of homeopathic doctrine. Homeopathy aligns with the principles of the Brazilian public health system, reflecting the latter's ethos of universality, accessibility, care coordination, and comprehensiveness, offering a whole-person approach to health care. Homeopathy's individualised approach and expanded view of the health–disease process, with emphasis on healthy lifestyle guidance, contributes to the promotion of individual good health and quality of life. These attributes of homeopathy make it a valuable therapeutic option, with relevance to the health service of Brazil as well as to that of other countries across the world.
Extremely asymmetric absorption and reflection near the exceptional point for three-dimensional metamaterial
Authors: Wu Yanjie , Zhang Ding , Li Qiuyu , Lin Hai , Shi Xintong , Xiong Jie , Hu Haoquan , Tian Jing , Wu Bian , Liu Y 
Published: May 2024

Abstract
In recent years, particular physical phenomena enabled by non-Hermitian metamaterial systems have attracted significant research interests. In this paper, a non-Hermitian three-dimensional metamaterial near the exceptional point (EP) is proposed to demonstrate extremely asymmetric absorption and reflection. Unlike its conventional counterparts, this proposed metamaterial is constructed with a loss-assisted design. Localized losses are introduced into the structure by combining our technique of graphene-based resistive inks with conventional printed circuit board process. Extremely asymmetric absorption and reflection near the EP are experimentally observed by tuning the loss between split ring resonators in the meta-atoms. Simultaneously, by linking the equivalent circuit model (ECM) with the quantum model, an equivalent non-Hermitian transmission matrix is constructed. We show that tuning the structure parameters of the ECM produces a metamaterial system with EP response. Our system can be used in the design of unidirectional metamaterial absorbers. Our work contributes to future works on the manipulation of EP to develop precision sensing and other applications in the 3D metamaterial platform.
Improved mixture correntropy cubature Kalman filter for attitude estimation
Authors: Qiao Meiying , Gao Kefei , Qiu Yunqiang , Han Haotian 
Published: May 2024

Abstract
This work proposes an algorithm based on improved mixture correntropy cubature Kalman filtering to address the issues of low accuracy and susceptibility to complex non-Gaussian noise and outlier interference in inertial navigation attitude estimation. First, a combination of Gaussian kernel and Cauchy kernel is proposed to construct the mixture correntropy, aiming to address the issue of single kernel-based correntropy being inadequate when dealing with complex non-Gaussian noise. Second, the objective function is established utilizing the model fitting loss based on mean square error and measurement fitting loss based on mixture correntropy. The maximum correntropy criterion is utilized to replace the minimum mean square error criterion, and the fixed-point iteration method is used to solve the objective function. This process derives the mixture correntropy matrix, which adjusts the measurement noise covariance. Finally, a membership function is used to determine the mixture correntropy coefficient. Accordingly, the algorithm can adaptively select the proportions of each kernel function based on the respective noise interference scenario. Simulations and dynamic–static experiments have been conducted. The algorithm has been compared with single kernel-based correntropy algorithms and other robust algorithms to confirm its superior precision and stability under complex non-Gaussian noise and outlier interference conditions.
A model-data combination driven digital twin model for few samples fault diagnosis of rolling bearings
Authors: Shi Huaitao , Yang Tianyi , Hu Yunjian , Song Zelong 
Published: May 2024

Abstract
Deep learning-based fault diagnosis methods for rolling bearings are widely utilized due to their high accuracy. However, they have limitations under conditions with few samples. To address this problem, a model-data combination driven digital twin model (MDCDT) is proposed in this work for fault diagnosis with few samples of rolling bearings. The simulation signals generated by different fault dynamic models of rolling bearings and the measured signals are mixed through MDCDT. The MDCDT generates virtual signals to bridge the gap between the simulated signals and the measured signals by combining their respective advantages. This paper also proposes image coding method based on the Markov transfer matrix (MTMIC) to convert one-dimensional vibration signals into two-dimensional images with both frequency domain information and time domain information, making it easier to extract fault features in neural network training. In the end, the developed MDCDT was evaluated using real rolling bearing data. Experiments show that the MDCDT can generate virtual data for fault diagnosis, and the fault diagnosis accuracy is significantly improved.
A novel stick-slip piezoelectric actuator is developed based on a parallelogram flexible drive mechanism to minimize shear force
Authors: Zhang Tao , Ma Rui , Wang Yang , Bian Donglong , Zhang Jian , Wang Yuhang 
Published: May 2024

Abstract
A piezoelectric actuator utilizing a parallelogram flexible mechanism is proposed. This actuator harnesses the parasitic motion generated by a parallelogram driven by a piezoelectric element. It differs from existing actuation mechanisms based on a similar principle in that the piezoelectric stack is positioned on the outside of the parallelogram flexible mechanism, thus protecting it from shear forces. Finite element simulations and experiments confirm this. The analysis was conducted using theoretical analysis and finite element simulation. The optimal drive angle for the parallelogram flexible mechanism was determined through finite element simulation. Additionally, a prototype actuator and an experimental measurement system were developed to assess the operational performance of the proposed piezoelectric actuator. When the driving frequency is 475 Hz and the locking force is 5 N, the motion of the actuator achieves a maximum speed of 5.65 mm s−1 and a maximum horizontal load of up to 113 g; when the input frequency is 1 Hz and the input minimum starting voltage is 8 V, the minimum displacement resolution is 30 nm. A comparative analysis of experimental results, theoretical calculations, and finite element simulation results demonstrates the feasibility of the structural design.
Nonreciprocal collective dynamics in a mixture of phoretic Janus colloids
Authors: Tucci Gennaro , Golestanian Ramin , Saha Suropriya 
Published: May 2024

Abstract
A multicomponent mixture of Janus colloids with distinct catalytic coats and phoretic mobilities is a promising theoretical system to explore the collective behavior arising from nonreciprocal interactions. An active colloid produces (or consumes) chemicals, self-propels, drifts along chemical gradients, and rotates its intrinsic polarity to align with a gradient. As a result the connection from microscopics to continuum theories through coarse-graining couples densities and polarization fields in unique ways. Focusing on a binary mixture, we show that these couplings render the unpatterned reference state unstable to small perturbations through a variety of instabilities including oscillatory ones which arise on crossing an exceptional point or through a Hopf bifurcation. For fast relaxation of the polar fields, they can be eliminated in favor of the density fields to obtain a microscopic realization of the Nonreciprocal Cahn–Hilliard model for two conserved species with two distinct sources of non-reciprocity, one in the interaction coefficient and the other in the interfacial tension. Our work establishes Janus colloids as a versatile model for a bottom-up approach to both scalar and polar active mixtures.
A new approach to solve time-fractional Navier–Stokes equation
Authors: Sawant S , Deshpande R 
Published: May 2024

Abstract
This article presents a new technique for the solution of Time Fractional Navier–Stokes equation. The approach is a combination of Adomian decomposition method (ADM) with Kamal integral transform (KIT). The proposed method is implemented on time-fractional Navier–Stokes equation (TFNSEs) to yield the analytical solution. Illustrative examples in TFNSEs are discussed to validate the applicability of the technique. The graphical visualization of the solutions is also presented. Further, the obtained results are compared with the existing solution methods.
Nonzero current due to coherent dynamic electron transport through a dimer with no external bias
Authors: Karmakar Anirban , Gangopadhyay Gautam 
Published: May 2024

Abstract
We have proposed a mechanism of the interplay of injected coherence and decoherence dynamics of the system in electron transport through an excitonic dimer when it is simultaneously connected to thermocoherent electron source and a thermal electron sink. Due to such an interplay, the variation of current with the energy gap between two excitonic states which is the internal bias of the system, is largely affected and it markedly bears the signature of the decoherence dynamics. We have also shown an extension in the modification of Landauer conductance formula for electron transport through excitonic dimer. The current has the property of an asymmetry in spectral width which can be understood in terms of sum of two Lorentzian profiles. More remarkably we have shown that current due to electron transport through the dimer can also arise at zero external bias which is a purely quantum coherent effect of the source fermionic reservoir having zero thermal occupation number.
Impact of seasonal variations on low and mid-latitudes ionospheric electric field satellite measurements
Authors: Makhlouf Soraya , Djebli Mourad 
Published: May 2024

Abstract
Ionospheric electric field measurements are provided by the Langmuir probe onboard the DEMETER satellite. Because there are four probes, various combinations of them form double probes that yield measurements. However, only the combination of probe antennas (E3) and (E4) enables possible measurements of the ambient (natural) ionospheric electric field. For other combinations, the measured field is almost identical to the induced field resulting from satellite motion. On the basis of this, we conducted comparative studies of the measured and induced electric fields during different seasons (summer, autumn, winter, and spring) to determine the best period for ionospheric electric field measurements. Multiple orbits were selected during different periods when the satellite was exposed to solar radiation. In all seasons except winter, the profiles of the induced and measured ionospheric electric field are similar. This masking effect leads to an underestimation of the ambient electric field. However, the highest accuracy for the ambient field can be obtained during winter, when solar flux radiation is weaker than that during other seasons. The probe position and orbital altitude also play important roles in the behavior of the induced electric field.
Tunneling conductance of hybrid bilayer-single graphene junctions
Authors: Benlakhouy Nadia , Jellal Ahmed 
Published: May 2024

Abstract
We study the tunneling effect of two different junctions based on graphene. Firstly, we consider gapped monolayer graphene (MLG) bridging AA-bilayer graphene (BLG), and secondly, AB stacking. These two systems display a significant decrease in transmission in both setups, showing the adjustability of conductance through gap size manipulation. Furthermore, we identify distinct characteristics in both stackings, including Fano resonances and Fabry-Pérot-like oscillations. Examining conductance as a function of BLG region width gives away varying peaks in the conductance profile for both stackings, exhibiting diverse periods and shapes. We demonstrate that under specific parameter conditions, tunneling leads to zero conductance, contrasting with the case without bias. The coexistence of gap and bias introduces a complex pattern in conductance peaks, reflecting fluctuations in amplitude and frequency. Notably, our findings indicate that the gap induces a noteworthy shift in the conductance profile in AB stacking, suggesting a modification of electronic properties. In AA stacking, minima are particularly evident in the conductance profile, especially for small bias values.
Antiproton bounds on dark matter annihilation from a combined analysis using the DRAGON2 code
Authors: De La Torre Luque Pedro , Winkler Martin Wolfgang , Linden Tim 
Published: May 2024

Abstract
Early studies of the AMS-02 antiproton ratio identified a possible excess over the expected astrophysical background that could be fit by the annihilation of a weakly interacting massive particle (WIMP). However, recent efforts have shown that uncertainties in cosmic-ray propagation, the antiproton production cross-section, and correlated systematic uncertainties in the AMS-02 data, may combine to decrease or eliminate the significance of this feature. We produce an advanced analysis using the DRAGON2 code which, for the first time, simultaneously fits the antiproton ratio along with multiple secondary cosmic-ray flux measurements to constrain astrophysical and nuclear uncertainties. Compared to previous work, our analysis benefits from a combination of: (1) recently released AMS-02 antiproton data, (2) updated nuclear fragmentation cross-section fits, (3) a rigorous Bayesian parameter space scan that constrains cosmic-ray propagation parameters.

We find no statistically significant preference for a dark matter signal and set strong constraints on WIMP annihilation to bb̅, ruling out annihilation at the thermal cross-section for dark matter masses below ∼ 200 GeV. We do find a positive residual that is consistent with previous work, and can be explained by a ∼ 70 GeV WIMP annihilating below the thermal cross-section. However, our default analysis finds this excess to have a local significance of only 2.8σ, which is decreased to 1.8σ when the look-elsewhere effect is taken into account.
Singular space-times with bounded algebraic curvature scalars
Authors: Magalhães Renan B. , Ribeiro Gabriel P. , Lima Junior Haroldo C.D. , Olmo Gonzalo J. , Crispino Luís C.B. 
Published: May 2024

Abstract
We show that the absence of unbounded algebraic curvature invariants constructed from polynomials of the Riemann tensor cannot guarantee the absence of strong singularities. As a consequence, it is not sufficient to rely solely on the analysis of such scalars to assess the regularity of a given space-time. This conclusion follows from the analysis of incomplete geodesics within the internal region of asymmetric wormholes supported by scalar matter which arise in two distinct metric-affine gravity theories. These wormholes have bounded algebraic curvature scalars everywhere, which highlights that their finiteness does not prevent the emergence of pathologies (singularities) in the geodesic structure of space-time.
By analyzing the tidal forces in the internal wormhole region, we find that the angular components are unbounded along incomplete radial time-like geodesics. The strength of the singularity is determined by the evolution of Jacobi fields along such geodesics, finding that it is of strong type, as volume elements are torn apart as the singularity is approached. Lastly, and for completeness, we consider the wormhole of the quadratic Palatini theory and present an analysis of the tidal forces in the entire space-time.
Utilising redundancy in musculoskeletal systems for adaptive stiffness and muscle failure compensation: a model-free inverse statics approach
Authors: Almanzor Elijah , Sugiyama Taku , Abdulali Arsen , Hayashibe Mitsuhiro , Iida Fumiya 
Published: May 2024

Abstract
Vertebrates possess a biomechanical structure with redundant muscles, enabling adaptability in uncertain and complex environments. Harnessing this inspiration, musculoskeletal systems offer advantages like variable stiffness and resilience to actuator failure and fatigue. Despite their potential, the complex structure presents modelling challenges that are difficult to explicitly formulate and control. This difficulty arises from the need for comprehensive knowledge of the musculoskeletal system, including details such as muscle arrangement, and fully accessible muscle and joint states. Whilst existing model-free methods do not need explicit formulations, they also underutilise the benefits of muscle redundancy. Consequently, they necessitate retraining in the event of muscle failure and require manual tuning of parameters to control joint stiffness limiting their applications under unknown payloads. Presented here is a model-free local inverse statics controller for musculoskeletal systems, employing a feedforward neural network trained on motor babbling data. Experiments with a musculoskeletal leg model showcase the controller’s adaptability to complex structures, including mono and bi-articulate muscles. The controller can compensate for changes such as weight variations, muscle failures, and environmental interactions, retaining reasonable accuracy without the need for any additional retraining.
Safeguarding the Environment: A Review of Functional Coating Systems for Rapid COVID-19 Inactivation
Authors: Adeboye S.A. , Adebamiro O.M. , Arigbede O.E. , Irorevbo H.E. , Siyanbola T.O. 
Published: May 2024

Abstract
The COVID-19 pandemic was a worldwide disaster in the health industry, millions of human deaths were recorded. The spread of the virus led to the shutting down of the world economy. The most prevalent is people communicating in close contact. Measures such as the use of nose masks and social distancing help to reduce the infection rate. The second is infection from substrates like tables, automated teller machine buttons, staircase rails, door nubs, etc. This paper is poised to review how surface-infected (substrates) platforms can be inactivated using modified functional coating systems. These coating composite systems are prepared by functionalizing the polymer matrix with suitable nanoparticles that could inactivate the SARS-CoV-2 virus. Furthermore, this piece discusses the challenges and future directions in the development of advanced coating technologies, aiming to enhance their effectiveness and applicability in diverse settings, including healthcare facilities and public spaces. This review serves as a valuable resource for scientists, engineers, and policymakers involved in the ongoing efforts to combat the COVID-19 pandemic.