bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thromboembolic Complications in Takotsubo Cardiomyopathy
Authors: Habib Manhal , Aronson Doron 
Published: October 2024

AbstractApical ballooning syndrome, commonly known as Takotsubo syndrome, is a distinct cardiomyopathy often resembling acute myocardial infarction in presentation. Takotsubo syndrome patients exhibit varied patterns of left ventricular wall motion abnormalities, most frequently apical dyskinesis with basal hyperkinesis, that are characteristically transient. Although emotional or physical stressors precipitate Takotsubo syndrome in most cases, a significant proportion presents without identifiable triggers, with a pronounced female predominance. Despite recovery of left ventricular function, Takotsubo syndrome may lead to serious complications akin to acute coronary syndromes. The pathophysiology remains incompletely understood, with catecholamine surge implicated in the genesis of myocardial injury, although direct causation remains debated. Diagnosis involves integrating clinical history, imaging modalities like echocardiography, and cardiac MRI. Psychiatric disorders, particularly anxiety and depression, are frequently associated with Takotsubo syndrome, suggesting a role of chronic stress in disease susceptibility. Management includes supportive care, with anticoagulation considered in cases of apical thrombus, alongside close monitoring for complications and recovery of left ventricular function. This article reviews the current understanding, challenges in diagnosis, and management strategies for Takotsubo syndrome.
Surface plasmons on silver gratings transform pyrolytic carbon into luminescent graphitized carbon dots
Authors: Walia Jaspreet , Rashid Sabaa , Amiri Naeini Maryam Sadat , Killaire Graham , Variola Fabio , Weck Arnaud , Berini Pierre 
Published: October 2024

Plasmonic catalysis holds the promise of opening new reaction pathways that are inaccessible thermally or via direct UV–vis electronic transitions. Here, energetic carriers produced via the decay of surface plasmons excited by visible light at 532 nm (2.33 eV, green) on a Ag-grating-bearing pyrolytic carbon residue drive its transformation into light-emitting graphitized carbon dots. The pyrolytic carbon residue is detectable via high-magnification surface-enhanced Raman scattering but cannot be directly observed using optical, electron, atomic force, or helium ion microscopy. When a Ag-grating-bearing pyrolyzed residue is introduced into a high-purity O2-depleted gas environment (Ar, N2, and CO2) and excited with 532 nm light, bright yellow luminescence emerges and is readily observed. Light emission is not observed without the pyrolytic carbon, without the excitation of plasmons, or in air or an Ar/O2 gas mixture. This process, driven by visible light and a nanostructured Ag surface bearing pyrolytic carbon, will be of interest to researchers involved in plasmonic catalysis, catalytic processes involving carbon, and luminescent plasmonic surfaces.
de Sitter Teukolsky waves
Authors: Harsh  , Hoque Sk Jahanur , Kashyap Sitender Pratap , Virmani Amitabh 
Published: October 2024

Abstract
We present de Sitter Teukolsky waves—linearised quadrupolar gravitational waves in the transverse-traceless gauge in de Sitter spacetime. In the cosmological constant Λ going to zero limit, our solutions match to Teukolsky solutions. For non-zero Λ, we compare our solutions to the wider literature, where different authors have constructed linearised gravitational perturbations in de Sitter spacetime with varied motivations. For de Sitter Teukolsky waves, we compute the energy flux across future timelike infinity

I

+

and show that it is manifestly positive.
Efficient Bayesian inference and model selection for continuous gravitational waves in pulsar timing array data
Authors: Bécsy Bence 
Published: October 2024

Abstract
Finding and characterizing gravitational waves from individual supermassive black hole binaries is a central goal of pulsar timing array experiments, which will require analysis methods that can be efficient on our rapidly growing datasets. Here we present a novel approach built on three key elements: (i) precalculating and interpolating expensive matrix operations; (ii) semi-analytically marginalizing over the gravitational-wave phase at the pulsars; (iii) numerically marginalizing over the pulsar distance uncertainties. With these improvements the recent NANOGrav 15 yr dataset can be analyzed in minutes after an

O

(
1

h

)

setup phase, instead of an analysis taking days–weeks with previous methods. The same setup can be used to efficiently analyze the dataset under any sinusoidal deterministic model. In particular, this will aid testing the binary hypothesis by allowing for efficient analysis of competing models (e.g. incoherent, monopolar, or dipolar sine wave model) and scrambled datasets for false alarm studies. The same setup can be updated in minutes for new realizations of the data, which enables large simulation studies.
The role of flow field dynamics in enhancing volatile organic compound conversion in a surface dielectric barrier discharge system
Authors: Böddecker Alexander , Passmann Maximilian , Segura Angie Natalia Torres , Bodnar Arisa , Awakowicz Felix , Oppotsch Timothy , Muhler Martin , Awakowicz Peter , Gibson Andrew R , Korolov Ihor , Mussenbrock Thomas 
Published: October 2024

Abstract
This study investigates the correlation between flow fields induced by a surface dielectric barrier discharge (SDBD) system and its application for the volatile organic compound gas conversion process. As a benchmark molecule, the conversion of n-butane is monitored using flame ionization detectors, while the flow field is analyzed using planar particle image velocimetry. Two individual setups are developed to facilitate both conversion measurement and investigation of induced fluid dynamics. Varying the gap distance between two SDBD electrode plates for three different n-butane mole fractions reveals local peaks in relative conversion around gap distances of 16–22 mm, indicating additional spatially dependent effects. The lowest n-butane mole fractions exhibit the highest relative conversion, while the highest n-butane mole fraction conversion yields the greatest number of converted molecules per unit time. Despite maintaining constant energy density, the relative conversion exhibits a gradual decrease with increasing distances. The results of the induced flow fields reveal distinct vortex structures at the top and bottom electrodes, which evolve in size and shape as the gap distances increase. These vortices exhibit gas velocity magnitudes approximately seven times higher than the applied external gas flow velocity. Vorticity and turbulent kinetic energy analyses provide insights intothese structures’ characteristics and their impact on gas mixing. A comparison of line profiles through the center of the vortices shows peaks in the middle gap region for the same gap distances, correlating with the observed peaks in conversion. These findings demonstrate a correlation between induced flow dynamics and the gas conversion process, bridging plasma actuator studies with the domain of chemical plasma gas conversion.
The degradation mechanism of high power S-band AlGaN/GaN HEMTs under high temperature
Authors: Yan Shumeng , Yang Tianying , Yuan Tingting , Liu Guoguo , Xu Tao , Chen Lijie , Cheng Chuan , Chen Gaopeng 
Published: October 2024

Abstract
The radio frequency (RF) degradation mechanism under high temperature is proposed in this paper. The saturated output power (P
sat), power added efficiency (PAE) and gain of the HEMTs deteriorate significantly under high power dissipation operation conditions, which contribute to an elevation of the junction temperature (T
j). The high T
j causes a negative shift of the threshold voltage and a reduction of electron mobility, as well as enhancing the trapping effects of the devices. As a result, the P
sat and PAE of the high-power HEMTs (P
sat = 152 W) decreased by 0.76 dB and 8.3%, respectively, which is more severe compared to low-power HEMTs (P
sat = 20 W), where P
sat and PAE reduced by 0.16 dB and 3.1% when the operation temperature was increased from 25 °C to 150 °C. By increasing the gate-to-drain distance from 1.625 to 2.175 μm, drain current stability and high temperature reverse bias reliability are improved. The results demonstrate that the trapping effect can be suppressed by decreasing the electric field under the gate; therefore, the RF output characteristics are boosted by 1.2 W, 1 dB and 2.6% for a device with gate width of 11.52 mm.
Study lepton flavor violation

B

0

⃗

l

i

±

l

j

∓

within the mass insertion approximation
Authors: Wang Yi-Tong , Ma Jiao , Han Xing-Yu , Long Xin-Xin , Wang Tong-Tong , Zhang Hai-Bin , Zhao Shu-Min 
Published: October 2024

Abstract
We study lepton flavor violating (LFV) decays

B

0

→

l

i

±

l

j

∓

(B
0 → eμ, B
0 → eτ and B
0 → μτ) in the U(1)
X
SSM (SSM is acronym for the supersymmetric standard model), which is the U(1)
X
extension of the minimal supersymmetric standard model (MSSM). The local gauge group of U(1)
X
SSM is SU(3)
C
×SU(2)
L
× U(1)
Y
× U(1)
X
. These processes (B
0 → eμ, B
0 → eτ and B
0 → μτ) are strictly forbidden in the standard model, but these LFV decays are a signal of new physics. We use the mass insertion approximation to find sensitive parameters that directly influence the result of the branching ratio of LFV decay

B

d

→

l

i

±

l

j

∓

.

Combined with the latest experimental results, we analyze the relationship between different sensitive parameters and the branching ratios of the three processes. According to the numerical analysis, these elements are very restricted from the non observation of charged lepton flavor violation (CLFV).
Triaxial deformation, shell structure, shell corrections and the connection to alpha-clustering in nuclei
Authors: Clark Georgina , Taylor Holly , Freer Martin 
Published: October 2024

Abstract
We explore the connection between the appearance of quasi-stable structures in mean-field type calculations, which arise as a result of the evolution of the underlying shell structure as a function of deformation, and α-clustering in light even–even nuclei. The Nilsson–Strutinsky mean-field approach employs a macroscopic liquid-drop whose energy is modified by a shell correction term derived using the Strutinsky method. This method reflects the variations in the energies of the single-particle states with deformation. As such, there is no obvious connection to clustering. Here we use the changing level scheme of the deformed harmonic oscillator as a function of triaxial deformation to fully explore the variation in stability of α-cluster structures in light even–even nuclei. The energies of the harmonic oscillator levels are used to deduce the energy required to disrupt the α-cluster as a function of the triaxial deformation. We find that there is good agreement between variations in the shell correction energy in the mean-field method and the energy required to disrupt the α-cluster. This provides a necessary link between understanding of the appearance of quasi-stable α-cluster structures and quasi-stable shapes appearing in mean-field calculations.
Electronic, optical and thermoelectric behavior of KCuX (X = S, Se, Te) monolayers
Authors: Gupta Neelam , Kumar Shubham , Rani Shivani , Kumari Puja , Kar Subhasmita , Ahuja Rajeev , Jyoti Ray Soumya 
Published: October 2024

Abstract
In the past few decades, two-dimensional materials gained huge deliberation due to their outstanding electronic and heat transport properties. These materials have effective applications in many areas such as photodetectors, battery electrodes, thermoelectrics, etc. In this work, we have calculated structural, electronic, optical, and thermoelectric (TE) properties of KCuX (X = S, Se, Te) monolayers (MLs) with the help of first-principles-based calculations and semi-classical Boltzmann transport equation. The phonon dispersion calculations demonstrate the dynamical stability of the KCuX (X = S, Se, Te) MLs. Our results show that the MLs of KCuX (X = S, Se, Te) are semiconductors with band gaps of 0.193 eV, 0.26 eV, and 1.001 eV respectively, and therefore they are suitable for photovoltaic applications. The optical analysis illustrates that the maximum absorption peaks of the KCuX (X = S, Se, Te) MLs are located in the visible and ultraviolet regions, which may serve as a promising candidate for designing advanced optoelectronic devices. Furthermore, thermoelectric properties of the KCuS and KCuSe MLs, including Seebeck coefficient, electrical conductivity, electronic thermal conductivity, power factor and figure of merit are calculated at different temperatures of 300 K, 600 K, and 800 K. Additionally, we also focus on the analysis of Grüneisen parameter and various scattering rates to further explain their ultra-low thermal conductivity. Our results show that KCuS and KCuSe possess ultra-low lattice thermal conductivity value of 0.15

W

m

−
1

K

−
1

and 0.06

W

m

−
1

K

−
1

respectively, which is lower than those of recently reported KAgSe (0.26

W

m

−
1

K

−
1

at 300 K) and TlCuSe (0.44

W

m

−
1

K

−
1

at 300 K), indicating towards the large value of ZT. These materials are found to possess desirable thermoelectric and optical properties, making them suitable candidates for efficient thermoelectric and optoelectronic device applications.
Synchronous decomposition match-reassigning transform and its application in planetary gearbox fault diagnosis
Authors: Wu Hengshan , Zhi Shaodan , Fang Qiqiang , Liu Yang , Wang Tianyang , Cheng Weidong , Chu Fulei 
Published: October 2024

Abstract
Under time-varying operating conditions, the instantaneous frequency (IF) of the vibration signal of the planetary gearbox exhibits non-stationary time-varying closely spaced characteristics as well as non-proportional and non-synchronous characteristics. This in turn leads to challenges for traditional time-frequency analysis (TFA) methods to accurately identify its fault features and obtain accurate time-frequency representations (TFR). To address this challenge, in this study, a TFA method is proposed based on Synchronous Decomposition Match-Reassigning Transform (SDMRT). First, the successive variational mode decomposition (SVMD) is used to adaptively separate non-synchronous frequency components in the original vibration signal. Second, the chirp rate (CR) describing the signal harmonic structure is used to synchronously match each frequency component, obtaining the TFR corresponding to each component. Third, all TFRs are merged to obtain a complete TFA result. Finally, the energy spread is re-aggregated to the ridge of the IF using the reassignment principle, resulting in a new frequency estimation operator termed the Synchronous Decomposition Match-Reassigning Operator (SDMRO). SDMRT can adaptively separate non-proportional and non-synchronous IFs and realize precise matching of time-varying closely spaced IFs, thereby completing the TFR of the vibration signal generated by the planetary gearbox. By analyzing simulated signals and measured vibration signals from planetary gearboxes, Rényi entropy and IF estimation errors of SDMRT correspond to 12.14% and 0.59%, respectively. The energy concentration degree and IF estimation results are significantly better than other TFA methods, which proves the effectiveness and superiority of SDMRT.
GNSS-assisted optimal alignment method for low-cost SINS motion of vehicle
Authors: Yan Yuqian , Si Yongbo , Chen Guangwu , Zhou Xin , Li Pengpeng 
Published: October 2024

Abstract
To improve the alignment accuracy and environmental applicability of the micro-electromechanical system (MEMS)-based strapdown inertial navigation system (SINS), this study proposes a global navigation satellite system (GNSS)-assisted multi-vector determination of the attitude optimal indirect coarse alignment. Using the inertial information output from the inertial measurement unit and the velocity information from the GNSS, a simplified velocity observation vector is constructed and the velocity lever arm stemming from the mounting position inconsistencies of the GNSS and SINS is fed back into the velocity of the carrier system. When constructing the observation vectors, the integration interval is shortened by reconstructing the two-vector integration formula for reducing the cumulative error of the inertial device. The attitude matrix problem is defined as the Wahba problem, which is solved using the singular value decomposition method. Based on the relationship between gyro zero bias and misalignment angle, the corresponding state and measurement equations are designed. Furthermore, owing to the measurement noise uncertainty, the adaptive traceless Kalman filtering algorithm is introduced to realize the effective adaptation processing of the measurement noise. More accurate attitude matrix estimates are obtained by continuously correcting the carrier system transformation matrix. The running car experiment results show that the proposed method exhibits higher alignment accuracy and environmental applicability than the current MEMS strapdown inertial navigation coarse alignment method and the traditional optimization-based alignment method.
Compressed sensing with smooth L0 constraints for moving force identification from bridge response measurements
Authors: Liang Yi , Hou Zhilong , Yu Ling 
Published: October 2024

Abstract
Compressed sensing (CS), as an emerging information sampling technique, has been successfully applied in the field of moving force identification (MFI). However, existing MFI CS models often fail to obtain the optimal sparse solutions and frequently underestimate the amplitude of local impact forces. To effectively address this issue, a new CS method is proposed for MFI based on smooth L0 norm constraints and bridge response measurements. Firstly, a smooth function is used to approximate the L0 norm, establishing a noise CS reconstruction model for MFI. The introduction of the smoothing function can locally convexify the original MFI problem and enhance the smoothness and differentiability of the objective function, making the optimization problem easier to solve. Subsequently, the Polak–Ribiere–Polyak formula is adopted to point the descent direction of the new objective function, and the sparse solution is iteratively advanced through the conjugate gradient algorithm. Finally, the applicability and feasibility of the proposed method is confirmed by numerical simulations and vehicle–bridge interaction tests, respectively. The results show that the proposed method can accurately identify moving forces from limited measurements of bridge responses. Compared with existing methods, it can provide more precise sparse solutions with higher robustness to measurement noises, and address the issue of underestimating on the amplitude of local impact forces, which is expected to enhance the performance and in-situ applicability of MFI.
Enhancing machine learning multi-class fault detection in electric motors through entropy-based analysis
Authors: Palaiologou Ilias , Falekas Georgios , Antonino-Daviu Jose A , Karlis Athanasios 
Published: October 2024

Abstract
In the field of electric motor maintenance, this study introduces a transformative approach by integrating entropy-based algorithms with machine learning for enhanced multi-class fault detection. Employing Shannon, Renyi, and Tsallis entropy algorithms on standard fault detection measurements, the research significantly advances predictive maintenance strategies through a robust, early-indication, system-agnostic analysis. Detailed examination is conducted, comparing results derived from datasets that include statistical features (excluding entropy) against the proposed entropy-based datasets, when applied to a multi-layer perceptron classifier (MLPC). Optimization of the MLPC and all compared algorithms’ hyperparameters is done using the state-of-the-art Optuna tool to dynamically explore each search space, ensuring that each methodology performs adequately in a timely fashion while allowing for adaptation. The results showcase significant enhancement in classification accuracy of diverse electric motor operational states, facilitating the differentiation between healthy and various levels of fault conditions under assorted load scenarios. Computational analyses reveal favorable results related to execution time and memory overhead, thereby supporting the practicality in operations constrained by memory resources. Validation of the approach is achieved through laboratory experiments on a purpose-built test bench. Versatility of entropy-based measures through their proposed utilization in diverse fault indications is achieved by a demonstration in the field of mechanical fault detection with a focus on bearing faults through well-respected datasets.
Unconventional coil shape design of eddy current sensors and the effect of shape parameters on the micro/nano-scale metal film thickness measurement performance
Authors: Li Hongkai , Lu Xinghao , Wang Jinlong , Zhang Tong 
Published: October 2024

Abstract
The thickness of metal film is a critical parameter, especially in micro/nano-manufacturing, where high-precision measurement is essential. The eddy current method, a non-destructive testing technique, is well-suited for in-situ measurement of micro/nano-scale metal film thickness due to its superior performance. However, enhancing the measurement capabilities of eddy current sensors remains a significant challenge. In practical applications, thickness sensitivity and spatial resolution are two key performance indicators of eddy current sensors, and improving both simultaneously is difficult. While the sensitive element (coil) of an eddy current sensor has a substantial impact on thickness sensitivity, its effect on spatial resolution has received less attention. This study establishes an eddy current coil model based on electromagnetic field, defining both thickness sensitivity and spatial resolution in the context of micro/nano-scale metal film thickness measurement. Two unconventional coil shapes are introduced, contrasting with the traditional cylindrical design, to investigate the effect of coil shape parameters, specifically the spatial distribution of the coil turns, on the key performance indicators. Simulation results are corroborated through experimental validation. Based on a series of calculations and analyses, an optimization method for coil shape parameters is proposed using a defined comparison factor that balances both thickness sensitivity and spatial resolution, which offers a promising approach for improving coil shape design.