bluuebunny/crossref_metadata_2025 huggingface dataset:
Mid-term Follow-Up after Closed Reduction in Developmental Dysplastic Hips
Authors: Walter Sebastian G. , Ossendorff Robert , Bornemann Rahel , Zarghooni Kourosh , Peterlein Christian Dominik , Placzek Richard
Published: January 2025

Purpose Closed reduction and subsequent spica casting is the gold standard for treatment of unstable or dislocated developmental dysplastic hips (DDHs). There are few data on mid-term results after treatment of DDH, especially on closed reduction.

Methods Thirty-one consecutive patients with unstable or dislocated hips (n = 36) that were treated by fluoroscopic, contrast agent-supported closed reduction and spica casting were included and evaluated clinically and radiologically 2 and 5 years after treatment.

Results After 2 and 5 years, there were no significant differences between healthy and successfully treated hips that were detectable with respect to acetabular coverage (AC) angle, center-edge angle, and clinical stability of the hip. There was a significant difference at the 2-year follow-up between healthy hips and hips that needed to undergo secondary open reduction surgery (n = 4) with respect to the AC angle (p < 0.001).

Conclusion Closed reduction in DDHs results in acceptable clinical and radiological results in the mid-term follow-up. It remains unclear why some patients with subsequent sonographically matured hips show secondary deterioration and recurrence of dysplasia.
Antibiotic Prophylaxis and Empirical Antibiotic Therapy in Primary Arthroplasty and Periprosthetic Joint Infections: Current Practice and Need for Therapy Optimization
Authors: Rupp Markus , Walter Nike , Baertl Susanne , Lang Siegmund , Herbst Tanja , Hitzenbichler Florian , Alt Volker
Published: January 2025

The aim of the present work was to survey the situation of healthcare regarding the use of prophylactic and empirical antibiotics in primary arthroplasty and treatment of periprosthetic joint infections (PJI). For this purpose, a survey was conducted at German university and occupational accident hospitals. Survey data was compared to previously published data on the antimicrobial regimes of PJI (n=81) patients (n=81) treated in our department between 2017 and 2020. A homogeneous picture emerged for the prophylactic administration of antibiotics in the context of primary arthroplasty. In 93.2% (elective) and 88.6% (fracture treatment) of the hospitals, first or second generation cephalosporins were administered perioperatively for infection prophylaxis in primary hip arthroplasty. The empirical antibiotic treatment of PJIs showed a clearly inhomogeneous therapeutic picture. Monotherapy with an aminopenicillin plus a beta-lactamase inhibitor is used most frequently (38.7%); first and second generation cephalosporins are used second most frequently as monotherapy (18.2%). In light of the global problem of antibiotic multi-resistance, clinical use of antibiotics has to be reasonable and effective. The present results highlight the further need to improve awareness and following existing guidelines in the administration of empirical antibiotic therapy in PJI.
TAS-102 Plus Bevacizumab as an Effective and Well Tolerated Regimen in Chemotherapy-Refractory Advanced Colorectal Cancers – A Single Institution Retrospective Analysis
Authors: Joarder Ritam , Patel Dhwani , Tiwari Atul , Choudhary Jatin , Vana Pranaya , Shenoy Vallish , Mer Neha , Ramaswamy Anant , Bhargava Prabhat , Ostwal Vikas
Published: January 2025

Objective There are limited data on the utility of TAS-102 plus bevacizumab in patients with chemotherapy-refractory metastatic colorectal cancer (mCRC) treated in India.

Methods Patients diagnosed with chemotherapy-refractory mCRC, defined as having received at least prior oxaliplatin and irinotecan–based chemotherapy between January 2017 and January 2022, and who began treatment with a combination of TAS-102 and bevacizumab were retrospectively analyzed for demographic variables, survivals, and prognostic parameters. The primary endpoint of the study was estimation of the median overall survival (OS) by the Kaplan–Meier method.

Results The data of 143 patients satisfied the prespecified inclusion criteria and were included for analysis. There was a predominance of left-sided CRCs (78%) and patients having greater than two sites of distant metastases (87%), with 41% of patients with at least two lines of prior therapy. With a median follow-up of 11.6 months, the median OS of the entire cohort was 10.9 months, while the median progression-free survival was 4.4 months. The combination was well tolerated, with the most common grade 3/4 side effects being neutropenia (25%), anemia (6%), and thrombocytopenia (4%). Dose modifications in TAS-102 were required in 20% of patients, though this did not entail permanent cessation of TAS-102 in any patient. The presence of a resected primary was prognostic for improved OS (p < 0.001), while signet ring histology predicted inferior OS (p < 0.001).

Conclusion The combination of TAS-102 and bevacizumab is an efficacious and safe therapeutic option in patients with mCRC who have received at least two lines of prior systemic therapy. There were no requirements for cessation of the combination in the current study, underlying the well-tolerated nature of the combination.
Comparison of Synovialization and Clinical Outcomes between Anterior Cruciate Ligament Anteromedial Bundle Augmentation and Double-Bundle Anterior Cruciate Ligament Reconstruction
Authors: Ahn Gil Yeong , Hwang Sung Hyun , Kang Seo Won , Song Jun Hyeok , Park Jee Soo , Lee Yeong Hyeon
Published: January 2025

This study aimed to compare clinical outcomes and second-look arthroscopic findings between double-bundle anterior cruciate ligament (ACL) reconstruction for complete ACL rupture and anteromedial (AM) bundle augmentation with preservation of the posterolateral (PL) bundle in isolated AM bundle rupture. Between 2014 and 2021, we retrospectively analyzed 95 ACL reconstructions with at least 2 years of follow-up. Patients undergoing primary ACL reconstruction from January 2014 to June 2021 were included in the study. Double-bundle ACL reconstruction (group 1) was performed in the cases involving male patients, high activity levels, age below 40 years, or when there was a patient preference for double-bundle reconstruction. In contrast, for partial ACL ruptures with an intact PL bundle confirmed on preoperative magnetic resonance imaging, AM augmentation was performed (group 2). Preoperative and final follow-up clinical outcomes, along with synovial coverage during second-look arthroscopy, were compared between group 1 (65 cases) and group 2 (30 cases). Statistical analysis included correlation coefficients between the groups. The Lysholm score, Tegner activity scores, and International Knee Documentation Committee (IKDC) knee evaluation form score at final follow-up were 81.8 (±5.5), 7.2 (±0.9), and 79.4 (±6.7), respectively, in group 1, and they were 88.0 (±6.4, p = 0.038), 7.9 (±0.5, p = 0.042), and 86.2 (±5.4, p = 0.081), respectively, in group 2. For group 1, the Lachman test (p = 0.093) and the pivot shift test (p = 0.176) at the final follow-up showed no laxity in 57 and 59 knees, and there was plus one laxity in 8 and 6 knees. For group 2, there were no laxity in 27 and 28 knees, and plus one laxity in 3 and 2 knees. Synovial coverage area percentages of the grafted tendon were 74.3 (±10.7) and 86.9 (±7.3, p = 0.002) in groups and group 2, respectively, with superior synovial coverage observed in group 2. The AM bundle augmentation with preservation of the PL bundle in ACL injury yielded better synovial coverage and clinical scores compared with double-bundle ACL reconstruction for complete ACL rupture.
Virial coefficients of helium isotopes at low temperatures
Authors: Karnatsevich L. V. , Bogoyavlenskii I. V. , Titar’ L. P.
Published: January 2025

The values of the second (B) and third (C) virial coefficients for helium isotopes (3He and 4He) are obtained from the experimental P–V–T data in the intervals 0.3−8 atm of pressures, 0.001–0.03 mole/cm3 of densities, and 3−14 K of temperatures. Approximate analytic expressions have been derived in the temperature interval 2−60 K on the basis of these experimental results as well as on the available data in literature. The experimental values of B and C for 3He and 4He are analyzed with the help of the quantum law of corresponding states and the existing theoretical results for various forms of the pair potential of the interaction of helium atoms.
Nonlinear theory of electron drag of one-dimensional defects with a long-range potential
Authors: Gumen L. N. , Krokhin A. A.
Published: January 2025

The problem of deceleration of a one-dimensional defect of the dislocation type in a metal is considered. It is shown that in view of the long-range nature of the electron-dislocation interaction potential, it is necessary to take into account nonlinear effects of the trajectory type. The obtained value of electron viscosity is much higher than that calculated earlier on the basis of the linear theory. Such an increase in electron viscosity helps to remove contradictions between the theory and experiment.
Dilute solid solutions of 14N2, 15N2, and CO in Ar at helium temperatures: heat capacities and rotational spectra of impurity molecules
Authors: Krivchikov A. I. , Bagatskii M. I. , Manzhelii V. G. , Minchina I. Ya. , Muromtsev P. I.
Published: January 2025

Heat capacities of dilute solid solutions of 15N2 and CO in Ar are studied in the temperature range from 0.5 to 6 K for impurity concentrations n ≥ 0.25 mol.%. The obtained results are considered together with the available data on heat capacity of dilute solutions of 14N2 in Ar. An energy spectrum of retarded rotational motion of isolated N2 and CO molecules in solid argon is proposed.
Long-wave IR spectroscopic studies of low-energy states of KDy(MoO4)2 in the region of low-temperature phase transition
Authors: Bagulya V. A. , Zvyagin A. I. , Kut’ko V. I. , Skorobogatova I. V.
Published: January 2025

Spectroscopic data for KDy(MoO4)2 in the long-wave IR region are considered. The measurements are made directly in the frequency range corresponding to the energy separation between two lower levels of the ground term 6H15/2 of the Dy3+ ions. The measurement of the Zeeman effect in the longitudinal and transverse magnetic fields makes it possible to resolve the electron and phonon lines in the low-frequency spectrum of KDy(MoO4)2.
A simulation and experimental study of a valveless piezoelectric micropump based on the synthetic jet principle
Authors: Lv Wencheng , Ni Jiafeng , Xuan Weipeng , Li Yixing , Huang Xiwei , Sun Lingling , Jin Hao , Dong Shurong , Luo Jikui
Published: January 2025

A stacked piezoelectric micropump based on the synthetic jet principle with a size of 22 × 22 × 5 mm3 is designed and fabricated. Through theoretical and finite element method (FEM) analysis, the conditions for achieving a synthetic jet structure are obtained, and the gas flow properties inside the chamber are analyzed. The first-order mode and resonant frequency of the piezoelectric actuator are simulated. At a resonant frequency of 22.5 kHz, the maximum central displacement of the actuator can reach 12.3 μm. In addition, the key dimensions of the micropump are optimized to improve the output flow rate. Experiments on the prototype of the micropump show that it can reach a maximum output flow rate of 618 mL/min when driven by a sine wave signal of 42 Vpp and 22.5 kHz. The power dissipation does not exceed 600 mW.
Exploring the potential of neuromorphic computing
Authors: Thompson Avery
Published: January 2025

Materials and designs mimicking brain functions can lead to faster processing, new capabilities, and increased energy efficiency.
Energy evolution of a general one-dimensional oscillator with a quadratic time-dependent stiffness and a linear time-dependent correlation parameter
Authors: Dodonov V. V. , Dodonov A. V.
Published: January 2025

We solve the time-dependent Schrödinger equation describing a generalized harmonic oscillator in the coordinate representation with constant mass but time-dependent stiffness and correlation parameters. Exact solutions are obtained in terms of confluent hypergeometric functions or parabolic cylinder functions. The dynamics of mean energy is studied in several different regimes, including the special case of imaginary correlation parameter, corresponding to the non-Hermitian Ahmed–Swanson model. In this case, real time-dependent mean values of the Hamiltonian are obtained by using dual wave functions, evolving according to the time-dependent Schrödinger equations with the given Hamiltonian and its Hermitially conjugated partner. The adiabatic evolution is considered as one of examples.
Non-relativistic limit of fermion ground states for the relativistic Vlasov-Poisson system
Authors: Jin Sangdon , Jang Junyeong
Published: January 2025

In this paper, we study the non-relativistic limit for fermion ground states of the relativistic Vlasov-Poisson energy (rVP) under a mass constraint. Jang and Seok [Kinet. Relat. Models 15(4), 605–620, (2022)] constructed fermion ground states of (rVP), and Dolbeault et al. [Arch. Ration. Mech. Anal. 171(3), 301–327, (2004)] found fermion ground states of non-relativistic Vlasov-Poisson energy (VP). Applying a variational approach, we prove that as the speed of light c goes to the infinity, the fermion ground states of (rVP) converge strongly to the fermion ground states of (VP) with a same mass constraint.
Novel robust control with disturbance rejection for permanent magnet synchronous motors and experimental validation
Authors: Wang Zheng , Zhen ShengChao , Huang Qiong , Liu XiaoLi , Chen Ke , Chen Ye-Hwa , Gao Liansheng , Feng Zailin
Published: January 2025

A novel robust control strategy is proposed in this work to address the dynamic control problem of permanent magnet synchronous motors (PMSM) position tracking and lessen the effect of system parameter and load fluctuations on the dynamic performance of PMSM. The tracking performance is improved by a robust control element built with the Lyapunov method to reduce the impact of uncertain factors such as parameter uncertainty, nonlinear friction, and external interference; the nominal control element is stabilized by the dynamics model. The uniformly bounded and uniformly final bounded systems are proven, and the associated conclusions are provided using the Lyapunov minimax approach. In this work, modeling and experimental investigation are conducted using the cSPACE fast controller, based on the permanent magnet synchronous motor test platform. The results of the testing and simulation show that the developed controller can effectively regulate the permanent magnet synchronous motor and achieve more accurate position tracking even in the face of ambiguity.
Advanced thermal boundary resistance measurement techniques for thick-film diamond heterostructures
Authors: Lu Xiaozhuang , Liu Qingbin , Yu Cui , Feng Shiwei , Feng Zhihong , Li Haibing , Pan Shijie , He Zezhao , Li Xuan , Zhou Chuangjie
Published: January 2025

With the miniaturization of electronic devices, thermal management has become a critical challenge, especially for high-power systems where efficient heat dissipation is essential. Polycrystalline diamond films, renowned for their exceptional thermal conductivity, offer a promising solution. However, the thermal boundary resistance (TBR) at the diamond/substrate interface remains a significant bottleneck, severely impacting heat dissipation efficiency. This study presents a measurement approach tailored for quantifying TBR in thick-film diamond heterostructures, focusing on diamond-on-silicon (Diamond-on-Si) systems with a silicon nitride barrier layer. Compared to conventional methods, such as transient thermoreflectance techniques, which often exhibit limited sensitivity for thick layers, this approach demonstrates greater reliability and applicability. The findings establish a foundation for advancing strategies to reduce TBR and improve the thermal management performance of diamond films in high-power electronic applications.
Dynamical properties of hydrogen fluid at high pressures
Authors: Gliaudelis G. , Lukyanchuk V. , Chtchelkatchev N. , Saitov I. , Kondratyuk N.
Published: January 2025

The properties of the hydrogen fluid at high pressures are still of interest to the scientific community. The experimentally unreachable dynamical properties could provide new insights into this field. In 2020 [Cheng et al., Nature 585, 217–220 (2020)], the machine-learned approach allows the calculation of the self-diffusion coefficient in the warm dense hydrogen with higher precision. After that, the work [van de Bund et al., Phys. Rev. Lett. 126(22), 225701 (2021)] reports the ab initio treatment of isotopic effects on diffusion in H2/D2 and a significant increase in its value in the region of the phase transition. Both works indicate the anomalous growth of diffusion, but the reasons for this phenomenon are unclear. In the present work, we reveal the plasma-like behavior of the diffusion growth. We apply the classical molecular dynamics method using a machine learning potential developed on the ab initio modeling for the prediction of diffusion and shear viscosity coefficients. We consider dependencies of the vibrational spectrum, molecule lifetime, diffusion, and shear viscosity coefficients on density along the isotherms in the temperature range from 600 to 1100 K.
Dielectric profile at the Pt(111)/water interface
Authors: Zhu Jia-Xin , Cheng Jun , Doblhoff-Dier Katharina
Published: January 2025

The dielectric constant, although a simplified concept when considering atomic scales, enters many mean-field, electrochemical interface models and constant potential models as an important parameter. Here, we use ab initio and machine-learned molecular dynamics to scrutinize the behavior of the electronic contribution to ɛr(z) as a function of distance z from a Pt(111) surface. We show that the resulting dielectric profile can largely be explained as a sum of the metallic response and the density-scaled water response at the interface. A slight enhancement of the dielectric response close to the surface can be explained by elongated, strongly polarizable orbitals induced by metal/water bonding. In spite of this enhancement, our results suggest the presence of a region with a very low dielectric constant close to the surface (where the orientational dielectric response does not kick in yet), even for water in contact with hydrophilic metallic interfaces. This region will restrict the double layer capacitance to relatively low values even at potentials where dielectric saturation does not play a role yet. This finding has implications on possible interpretations of double layer capacitances, the dependence of surface electric fields on the ion size, and on electrochemical kinetics.
Three-dimensional Phan-Thien-Tanner viscoelastic flows around a sphere
Authors: Zamani–Taghizadeh–Rabe Moein , Norouzi Mahmood , Abass Nejad Ali , Minaeian Ali , Izadifard Mohammad Hossein
Published: January 2025

This study investigates the steady and unsteady flow of a viscoelastic fluid around a sphere in three-dimensional space. Numerical simulations using the finite volume method incorporated a logarithmic mapping technique to overcome divergence issues at high elastic numbers. The fluid's behavior was characterized by the Phan-Thien-Tanner model, renowned for its accuracy and parametric simplicity. Key findings reveal that viscosity variations and stress relaxation times are pivotal in shaping the fluid's viscoelastic properties, surpassing the influence of other factors. Notably, the drag coefficient exhibited diverse behaviors—in some cases increasing, in others decreasing, and at times remaining constant—across different elasticity numbers. The study also explored the impact of fluid dilution, elasticity, and viscosity ratio on shear stress and drag coefficient variations, highlighting the profound role of elasticity in modulating the drag coefficient. A rise in velocity, elasticity number, viscosity ratio, and slip parameter was found to correspond with an increase in the drag coefficient, whereas an enhancement of the first model parameter reduced velocity, allowing viscous losses to dominate flow dynamics. The critical Reynolds number for Newtonian fluids was determined to be 300, with a noticeable decline as elasticity increased. The viscosity ratio demonstrated a strong influence on the critical Reynolds number, while the model parameters had minimal impact. Additionally, it was observed that as the vortex separation ratio increased, vortex length extended, and the separation angle decreased.
Toward a 10-W level femtosecond erbium laser operating in the 1600 nm low gain region
Authors: Yang Haolin , Zhang Ruili , He Sailing
Published: January 2025

1.6 µm ultrafast lasers are important in biomedical applications because the wavelength is located within an attractive biological window called the near-infrared-II (NIR-II) region. However, for erbium- or thulium-doped fibers, 1.6 μm is not their typical gain wavelength; therefore, realizing a high power femtosecond (fs) 1.6 μm laser is a challenging task. In this work, we propose a pump scheme assisted by a C-band laser. The new pump scheme can improve the gain at 1.6 μm with a mechanism originating from the re-absorption effect of the ground state and the in-band relaxation between the splitting energy levels 4I13/2b and 4I13/2a. Applying the pump scheme to the all-fiber large-mode-area (LMA) chirped pulse amplification (CPA) system, we achieve a record-high output power of ∼9.42 W, corresponding to a 262 nJ single pulse energy. The pulse duration after compression is ∼361 fs. Our approach of combining a LMA CPA system with a C-band auxiliary laser co-pumping scheme opens a way to increase the output power of an erbium-doped fiber laser by one order of magnitude in the 1600 nm region, even though this is a low gain region.
Criteria for identifying and evaluating locations that could potentially host the Cosmic Explorer observatories
Authors: Daniel Kathryne J. , Smith Joshua R. , Ballmer Stefan , Bristol Warren , Driggers Jennifer C. , Effler Anamaria , Evans Matthew , Hoover Joseph , Kuns Kevin , Landry Michael , Lovelace Geoffrey , Lukinbeal Chris , Mandic Vuk , Pham Kiet , Read Jocelyn , Russell Joshua B. , Schiettekatte François , Schofield Robert M. S. , Scholz Christopher A. , Shoemaker David H. , Sledge Piper , Strunk Amber
Published: January 2025

Cosmic Explorer is a next-generation ground-based gravitational-wave observatory that is being designed in the 2020s and is envisioned to begin operations in the 2030s together with the Einstein Telescope in Europe. The Cosmic Explorer concept currently consists of two widely separated L-shaped observatories in the United States, one with 40 km-long arms and the other with 20 km-long arms. This order of magnitude increase in scale with respect to the LIGO-Virgo-KAGRA observatories will, together with technological improvements, deliver an order of magnitude greater astronomical reach, allowing access to gravitational waves from remnants of the first stars and opening a wide discovery aperture to the novel and unknown. In addition to pushing the reach of gravitational-wave astronomy, Cosmic Explorer endeavors to approach the lifecycle of large scientific facilities in a way that prioritizes mutually beneficial relationships with local and Indigenous communities. This article describes the (scientific, cost and access, and social) criteria that will be used to identify and evaluate locations that could potentially host the Cosmic Explorer observatories.
The characteristics of line-shaped defects and their impact mechanism on device performance in β-Ga2O3 Schottky barrier diodes
Authors: Liu Jinyang , He Song , Xu Guangwei , Hao Weibing , Zhou Xuanze , Zheng Zheyang , Long Shibing
Published: January 2025

Beta-phase gallium oxide (β-Ga2O3) has attracted increasing attention in the field of power electronic devices due to its ultra-wide bandgap and high Baliga figure-of-merit. However, the premature breakdown deteriorated with the increase in device area, hindering the scale-up of the current rating. In this work, we unveil the formation and characteristics of killer defects responsible for the premature breakdown in an Si-doped (001) β-Ga2O3 epitaxial layer grown by halide vapor phase epitaxy. The killer defects feature a line-shaped morphology along the [010] orientation. Specifically, the high-resolution transmission electron microscopy characterization links the line-shaped defects to underlying voids. These voids are surrounded by amorphous phase regions, and the transition from amorphous phase to crystalline phase results in twins extending along the [010] orientation, which eventually become line-shaped defects on the wafer. Additionally, the defect area exhibits smaller capacitance and lower surface potential compared to the defect-free region. This is attributed to the absence of local ionized donors in the defect area, leading to electric field concentration in this region. This study systematically investigates a killer defect in β-Ga2O3, which contributes to the scale-up process of β-Ga2O3 power devices and advances their application.
Turbulence affected by submerged aquatic vegetation under wind-induced flow
Authors: Wu Chenhui , Deng Jiang , Zhou Xiaojie , Gao Ang , Feng Kedong , Zhu Chunyue
Published: January 2025

Submerged aquatic vegetation (SAV) changes the turbulent structure of rivers, wetlands, estuaries, and lakes. However, few studies have focused on the influence of SAV on hydrodynamic characteristics under wind-induced flow. Therefore, laboratory experiments were conducted to study the effects of SAV on the flow structure and turbulence characteristics under wind-induced flow, and spectral based decomposition method was used to separate turbulence and wave velocity. Result shows that SAV reduced local velocity within canopy and elevates the location of the zero-velocity point. The canopy drag caused by SAV increases the decay rate of turbulent Reynolds stress along depth while hardly influencing wave Reynolds stress. Canopy drag depresses the turbulent RMS (root mean square) velocity and wave orbital velocity. The presence of SAV leads to the decrease in TKE (turbulent kinetic energy) production and dissipation rate within canopy. The canopy drag more effectively diminishes TKE production than it does the dissipation. Research on local isotropy of SAV in wind-induced flows shows that the presence of SAV promotes a gradual transition from local anisotropy to local isotropy in turbulence within canopy. Finally, quadrant analysis reveals that the presence of SAV reduced the probabilities and the contribution to turbulent momentum of ejection and sweep.
Generalizing morphologies in dam break simulations using transformer model
Authors: Mu Zhaoyang , Liang Aoming , Ge Mingming , Chen Dashuai , Fan Dixia , Xu Minyi
Published: January 2025

The interaction of waves with structural barriers, such as dam breaking, plays a critical role in flood defense and tsunami disasters. In this work, we explore the dynamic changes in wave surfaces impacting various structural shapes—circle, triangle, and square—using deep learning techniques. We introduce the “DamFormer,” a novel transformer-based model designed to learn and simulate these complex interactions. Additionally, we conducted zero-shot experiments to evaluate the model's ability to generalize across different domains. This approach enhances our understanding of fluid dynamics in marine engineering and opens new avenues for advancing computational methods in the field. Our findings demonstrate the potential of deep learning models like the DamFormer to provide significant insights and predictive capabilities in ocean engineering and fluid mechanics.
Wake and performance of floating offshore wind turbines under six degrees of freedom conditions
Authors: Zhou Tian , Lan Hui , Xu Chang , Han Xingxing , Wu Xilong
Published: January 2025

In the marine environment, floating offshore wind turbines (FOWTs) are exposed to perturbations of nonlinear motion response. An in-depth study of the evolution laws of wake vortex and wake deficit under six degrees of freedom conditions in FOWTs can help reduce the blade load and enhance the output for downstream wind turbines. This paper enhances the traditional actuator line model by incorporating velocity corrections that account for platform motion, enabling dynamic simulations of National Renewable Energy Laboratory 5 MW (Megawatt) reference rotor under six degrees of freedom (6-DOF) conditions, including surge, sway, heave, pitch, roll, and yaw. The results indicate except for the surge and pitch, the effect of the motion response of the remaining DOF on the average thrust and power of the FOWT is within 1%. The 6-DOF motion condition drives the evolution of the wake vortex into a vortex ring or long vortex band mode. The wake lengths for surge, sway, and heave are shortened to 0.7, 0.6, and 0.6 times those of the fixed conditions, respectively, while pitch, roll, and yaw slightly increase the wake lengths to 1.1, 1.2, and 1.2 times those of the fixed conditions. All DOF, except for yaw, tend to delay the onset of wake self-similarity, with yaw reducing it by 10% compared to the fixed conditions. The insights garnered from this paper provide guidance for developing engineering wake models and micrositing for floating offshore wind turbines.
Application of the Skanavi model to CaCu3Ti4O12 materials
Authors: Luo Hao , Geng Kejia , Qin Xinrui , Kong Cuncun , Liu Xin , Su Xueyan , Su Yaoheng , Lu Dingze , Cheng Pengfei
Published: January 2025

In this paper, the optical and static permittivities of CaCu3Ti4O12 supercells are calculated based on the Skanavi model by decomposing the electric field of molecules into the electric field of ions. The results show that the Skanavi model's theoretical predictions are significantly more accurate than those of the Clausius–Mossotti equation and Born model and are in good agreement with the experimental data. In addition, the absence of ferroelectricity in CaCu3Ti4O12 is also revealed by investigating the changes in the structural coefficients of the effective electric field caused by the displacement of Ti4+ along the z-axis. Finally, by analyzing the contribution of TiO6 octahedra or CuO4 planar squares to the static permittivity, the main polarization unit in the structure of CaCu3Ti4O12 has been discovered. This study not only makes up for the insufficient research on the polarization mechanism of CaCu3Ti4O12 but also provides a new tool to explore the polarization mechanism of other materials.
Numerical study and semi-analytical model of rocket motor exhaust backflow in rarefied atmosphere
Authors: Clout Antoine , Langenais Adrien , Dauvois Yann , Mieussens Luc , Labaune Julien
Published: January 2025

The prediction of backflow from multi-species high density rocket engine plume at high altitude, i.e., plume gases going upstream of the vehicle in rarefied atmospheric conditions remains a challenging numerical problem. Direct Simulation Monte Carlo computations are used to assess the sensitivity of backflow to plume and atmosphere inflow properties, and ultimately to derive a semi-analytical backflow model. It is found that backflow is independent of plume density in the thermal equilibrium limit at the nozzle exit plane, which allows for huge computational cost reductions in simulations to determine the backflow model parameters. The backflow behavior also appears to be dependent on two Knudsen numbers, representing the density effect in the far field atmosphere and in the compressed region in front of the vehicle. The ability of the model to estimate the backflow of specific species is finally demonstrated on a meter sized solid rocket case.
Stagnation point on the micropolar bioconvection nanofluid flow over inclined Riga plate: Keller box analysis
Authors: Shah Nehad Ali
Published: January 2025

This study aims to examine chemical reactive agents on the micropolar of a nanoliquid containing motile bacteria spreading over an incline on the Riga plate. An electromagnetic actuator installed on the surface is called a Riga plate. It comprises an array of alternating electrodes arranged spanwise and a permanent magnet. Because of their exceptional thermal performance, nanoparticles are valued in heat transfer systems, material sciences, electronics, etc. Gyrotactic microorganisms are also included to prevent potential deposition. In addition, consideration is given to radiative flow, heat source/sink, and chemical and convective conditions. Moreover, a series of converted model equations are considered from the principal constitution equations, and the effective Keller box technique numerically solves these ordinary differential equations. The effects of thermal field, concentration of nanoparticles, velocity, microrotation, and motile density profiles are shown numerically and graphically. It is noted that the velocity microrotational fields exhibit dwindled behavior as material variables intensified. Velocity was enhanced with the increasing values of the mixed convection variable and the modified Hartman number. For larger values of the radiation factor, the thermophoresis number, the Biot number, and the Brownian motion magnitude, the thermal flow behavior is enhanced. The drag friction and motile density reduce in percentage form. The current inspection has many uses in technical fields of study, including electromagnetism miniature pumping and nanomechanics.
Newton’s algorithm for discrete classical dynamics
Authors: Toxvaerd Søren
Published: January 2025

A recent article in J. Chem. Phys. argues that the two algorithms, the velocity-Verlet and position-Verlet integrators, commonly used in Molecular Dynamics (MD) simulations, are different [L. Ni and Z. Hu, J. Chem. Phys. 161, 226101 (2024)]. However, not only are the two algorithms just different formulations of the same discrete algorithm, but also are other simple discrete algorithms used in MD simulations in the natural sciences. They are all reformulations of the discrete algorithm derived by Newton in 1687 in Proposition I in the very first part of his book Principia. The different reformulations of Newton’s algorithm for discrete dynamics lead to identical discrete dynamics with the same invariances, momentum, angular momentum, and energy as Newton’s analytical dynamics. Hundreds of thousands of MD simulations with Newton’s discrete dynamics have appeared but unfortunately with many recorded errors for energies, potential energies, temperatures, and heat capacities. The public software for MD should be corrected.
Mobilisation and replenishment of phosphorus reserves in Bos indicus cows. 2. Mature lactating cows fed diets deficient or adequate in phosphorus
Authors: Dixon R. M. , Benvenutti M. A. , Goodwin K. L. , Anderson S. T. , Mayer R. J. , Isherwood P. , Kidd L. J. , Fletcher M. T.
Published: January 2025

Context Pastures growing on low phosphorus (P) soils are often P deficient, particularly for lactating cows. Aim To examine the effects of P-deficient diets on the performance of lactating multiparous cows. Methods From parturition, mature Bos indicus cross cows (n = 32, initially 474 kg liveweight (LW) and body condition score 3.5) were fed ad libitum for 14 weeks one of four diets: (i) high P (HP-HCa), (ii) low P with low calcium (LP-LCa), (iii) low P with high Ca (LP-HCa), or (iv) the LP-LCa diet with ammonium chloride (LP-LCa+ac). Results Voluntary feed intakes were higher for cows fed the HP-HCa than the three LP diets (23.1 vs 17.4–19.6 g DM/kg LW.day; P < 0.001). The HP-HCa cows gained 0.15 kg LW/day, whereas LP cows lost 0.14–0.51 kg LW/day; P < 0.05). The cows fed LP diets generally maintained milk production and calf growth comparable to that of HP-HCa cows (5.8 kg/day and 0.70 kg/day). The HP-HCa cows retained 6.0–6.4 g P/day from weeks 1–8, but P retention was negligible at week 14. The LP cows mobilised 4.9–9.1 g body P/day. Rib cortical bone shortly after parturition was 634 ± 127 (337–848) μg P/mm2 in the 12th rib, and indicated that the bone P reserves were deficient, marginal and adequate in 27, 37 and 37% of the cows, respectively. During lactation, rib bone P increased 23% in HP-HCa cows, changed little in the LP-LCa and LP-HCa cows (−4 and +7%), and decreased 13% (P < 0.05) in LP-LCa+ac cows. The change in rib cortical bone P during lactation was correlated with this measurement at parturition; the P per unit surface area of rib cortical bone of cows with low bone P at parturition did not change, but in cows with high bone P it decreased up to 16%. Plasma inorganic P averaged 1.49 mmol/L in the HP-HCa cows and <0.8 mmol/L in the LP cows. Plasma Ca, Ca/inorganic P ratio, 1,25-dihydroxy vitamin D3, bone alkaline phosphatase, and carboxy-terminal telepeptides of type 1 collagen increased during lactation (P < 0.05 to P < 0.001) in the LP cows. Conclusions When fed acutely P-deficient diets, mature cows of moderate LW and with body condition scores at parturition generally maintained milk secretion and calf growth by mobilisation of body reserves. Implications The capacity of beef cows to maintain lactation when ingesting P-deficient diets provides opportunities for improved herd management.
Epistatic hotspots organize antibody fitness landscape and boost evolvability
Authors: Schulz Steven , Tan Timothy J. C. , Wu Nicholas C. , Wang Shenshen
Published: January 2025

The course of evolution is strongly shaped by interaction between mutations. Such epistasis can yield rugged sequence–function maps and constrain the availability of adaptive paths. While theoretical intuition is often built on global statistics of large, homogeneous model landscapes, mutagenesis measurements necessarily probe a limited neighborhood of a reference genotype. It is unclear to what extent local topography of a real epistatic landscape represents its global shape. Here, we demonstrate that epistatic landscapes can be heterogeneously rugged and this heterogeneity may render biomolecules more evolvable. By characterizing a multipeaked fitness landscape of a SARS-CoV-2 antibody mutant library, we show that heterogeneous ruggedness arises from sparse epistatic hotspots, whose mutation impacts the fitness effect of numerous sequence sites. Surprisingly, mutating an epistatic hotspot may enhance, rather than reduce, the accessibility of the fittest genotype, while increasing the overall ruggedness. Further, migratory constraints in real space alleviate mutational constraints in sequence space, which not only diversify direct paths taken but may also turn a road-blocking fitness peak into a stepping stone leading toward the global optimum. Our results suggest that a hierarchy of epistatic hotspots may organize the fitness landscape in such a way that path-orienting ruggedness confers global smoothness.
The pragmatics of hashtags in French tweets
Authors: Hadour Taoues
Published: January 2025

Even though France is not a bilingual country, French Twitter users are using various hashtags in English. The
hashtag, which was originally created on Twitter, is a popular symbol widely used in the virtual world as well as in the real
world. The goal of the hashtag was to organize topics of discussion relative to common themes. Even though this remains its
primary usage, other functions for hashtags have emerged since its creation. In a Tag and Commentary hashtag analysis, this study
investigates the pragmatic functions and positions of 755 English hashtags on Twitter from all users geo-tagged in France. The
data was collected in all the regions of France through Twitter’s API (Application program interface) using the software RStudio.
The results show that English hashtags are predominantly used for advertising purposes at the end of a tweet. However, instances
of Commentary hashtags are also being used to add an evaluative role regarding the main body of tweets. Through this analysis, the
study contributes to a deeper comprehension of online linguistic practices among French users, shedding light on the complex
dynamics between language, technology, and communication in today’s digital era.
Regiocentric use and national indexicality
Authors: Niehaus Konstantin
Published: January 2025

Contemporary German linguistics uses either pluricentric or pluriareal models to investigate geographic variation in standard German. In this article, I argue for an integration of both concepts by including language ideologies and enregisterment (Agha 2007) more rigorously. First, I will elaborate on the idea of “core” areas in standard language use and ideologies where specific standard variants are most frequent or are promoted in discourse by ideology brokers. Speakers’ ideologies allow for salient geographic variants to index social meaning (e.g. national stereotypes) and constitute a linguistic register of identity. The interaction of use and indexicality is mediated by attitudes. I propose to integrate standard use, attitudes, and indexicality in a single preliminary framework which could also be useful for other languages with several standards.
Nonparametric signal separation in very-high-energy gamma ray observations with probabilistic neural networks
Authors: Ullmo M. , Moulin E.
Published: January 2025

An intriguing challenge in observational astronomy is the separation signals in areas where multiple signals intersect. A typical instance of this in very-high-energy (VHE, E ≳ 100 GeV) gamma-ray astronomy is the issue of residual background in observations. This background arises when cosmic-ray protons are mistakenly identified as gamma-rays from sources of interest, thereby blending with signals from astrophysical sources of interest.
We introduce a deep ensemble approach to determine a non-parametric estimation of source and background signals in VHE gamma observations, as well as a likelihood-derived epistemic uncertainty on these estimations.
We rely on minimal assumptions, exploiting the separability of space and energy components in the signals, and defining a small region in coordinate space where the source signal is assumed to be negligible compared to background signal.
The model is applied both on mock observations, including a simple toy case and a realistic simulation of dark matter annihilation in the Galactic center, as well as true observations from the public H.E.S.S. data release, specifically datasets of the Crab nebula and the pulsar wind nebula MSH 15-52.
Our method performs well in mock cases, where the ground truth is known, and compares favorably against conventional physical analysis approaches when applied to true observations.
In the case of the mock dark matter signal in the Galactic center, our work opens new avenues for component separation in this complex region of the VHE sky.
Proto-neutron stars with quark cores
Authors: Issifu Adamu , Menezes Débora P. , Rezaei Zeinab , Frederico Tobias
Published: January 2025

This work investigates the evolution of proto-neutron stars (PNSs) from birth as neutrino-rich objects to maturity as cold-catalyzed neutrino-poor objects with nucleonic and non-nucleonic degrees of freedom. The focus is on the star's core where the nucleons, hyperons, and the Δ-isobars are expected to dissolve into a “soup” of deconfined quarks, at higher baryon densities, to establish a possible hadron-quark phase transition. We separately calculate the nuclear equations of state (EoS) for the hadronic matter (composed of all the baryon octet and Δ-isobars) and the strange quark matter (SQM) under the same thermodynamic conditions characteristic of PNS and proto-strange star (PSS) evolution and construct the hybrid EoS using Maxwell's construction. The study allows us to determine the hadron-quark phase transitions along the evolution lines of the star. We observed a phase transition from hadronic matter to quark matter (QM) phase when the neutrinos have completely escaped from the star's core. The EoSs utilized are constrained to meet the 2 M⊙ threshold in accordance with the observational data.
Constraining primordial non-Gaussianity with Density-Split Clustering
Authors: Morawetz James , Paillas Enrique , Percival Will J.
Published: January 2025

Obtaining tight constraints on primordial non-Gaussianity (PNG) is a key step in
discriminating between different models for cosmic inflation. The constraining power from
large-scale structure (LSS) measurements is expected to overtake that from cosmic microwave
background (CMB) anisotropies with the next generation of galaxy surveys including the Dark Energy
Spectroscopic Instrument (DESI) and Euclid. We consider whether Density-Split Clustering (DSC) can
help improve PNG constraints from these surveys for local, equilateral and orthogonal types. DSC
separates a surveyed volume into regions based on local density and measures the clustering
statistics within each environment. Using the Quijote simulations and the Fisher information
formalism, we compare PNG constraints from the standard halo power spectrum, DSC power spectra and
joint halo/DSC power spectra. We find that the joint halo/DSC power spectra outperform the halo
power spectrum by factors of ∼ 1.4, 8.8, and 3.6 for local, equilateral and orthogonal PNG,
respectively. This is driven by the higher-order information that DSC captures on small scales. We
find that applying DSC to a halo field does not allow sample variance cancellation on large scales
by providing multiple tracers of the same volume with different local PNG responses. Additionally,
we introduce a Fourier space analysis for DSC and study the impact of several modifications to the
pipeline, such as varying the smoothing radius and the number of density environments and
replacing random query positions with lattice points.
Delicate curvature bounces in the no-boundary wave function and in the late universe
Authors: Lehners Jean-Luc , Quintin Jerome
Published: January 2025

Theoretical considerations motivate us to consider vacuum energy to be able to decay and
to assume that the spatial geometry of the universe is closed. Combining both aspects leads to the
possibility that the universe, or certain regions thereof, can collapse and subsequently undergo a
curvature bounce. This may have occurred in the very early universe, in a pre-inflationary
phase. We discuss the construction of the corresponding no-boundary instantons and show that they
indeed reproduce a bouncing history of the universe, interestingly with a small and potentially
observable departure from classicality during the contracting phase. Such an early bouncing
history receives a large weighting and provides competition for a more standard inflationary
branch of the wave function. Curvature bounces may also occur in the future. We discuss the
conditions under which they may take place, allowing for density fluctuations in the matter
distribution in the universe. Overall, we find that curvature bounces require a delicate
combination of matter content and initial conditions to occur, though with significant
consequences if these conditions are met.
Redshift dependence of FRB host dispersion measures across cosmic epochs
Authors: Acharya Sandeep Kumar , Beniamini Paz
Published: January 2025

We constrain the redshift dependence of (rest frame) host galaxy dispersion measures of localized Fast Radio Bursts (FRBs) by assuming it to vary as a simple power law (∝ (1+z)
α
). We simultaneously fit α as well as the host dispersion measure to the data of FRBs with known redshifts. We find that α between 0 to 1 is preferred depending upon our modelling choices. Current data can constrain |α| ≲ 2 at a 68 percent confidence interval. Such constraints have implications for our understanding of galaxy formation and can be used to inform galaxy and large scale simulations.