bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the dielectric and ferromagnetic behaviour of Ni and Co dual doped ZnO for diluted magnetic semiconductor
Authors: Kant Ravi 
Published: August 2024

Abstract
Herein, Ni/Co co-doped ZnO nanoparticles (NPs) were successfully prepared via chemical co-precipitation process. The structural, purity and crystallite size of as-prepared particles were confirmed by using x-ray diffraction (XRD). The results revealed the hexagonal wurtzite structure of ZnO without any impurity phase of as-prepared samples. The crystallite size decreased from 34.9 to 9.6 nm, whereas lattice strain reduced to 0.00086. The change in crystallite size, lattice parameters, strains and dislocation density further indicates the successful incorporation of dopants in ZnO host lattice. The dielectric properties, ac conductivity, and magnetic behaviour were steadily examined. The dielectric constant has been found to be 1070 with 5wt% at low frequency and become constant at higher frequency. It was revealed that dopant additions lead to attain high dielectric constant and low loss possibly attributed to interface polarization, and dipole polarization due to oxygen vacancy defects. M-H measurement observed that ferromagnetism at room temperature pure and doped ZnO samples. The ferromagnetic behaviour of pure ZnO NPs with Ms = 0.17 emu g−1, Mr = 0.11 emu g−1 and Hc = 67 which was increased to Ms = 0.85 emu g−1 and Mr = 0.65 emu/g for 5wt% Co. This improvement with increasing Co concentration indicates that oxygen defects may stabilize the ferromagnetic order. These interesting features encouraging to use this material for ultrahigh dielectric materials and spintronics.
The de Broglie-Einstein-Rosen gravitational wave
Authors: D’Errico Luca 
Published: August 2024

Abstract
de Broglie gravitational waves are solutions of the linearized Einstein's field equations in vacuum, with intriguing properties. They are axially symmetric and have an effective mass, which is responsible for longitudinal effects that are absent in standard gravity waves. Moreover, they represent a classical realization of a form of dynamics proposed for quantum particles by de Broglie one hundred years ago. In this paper we will show that this perturbation field can be obtained, apart from a proportionality constant, in the weak field limit of a particular Einstein-Rosen field, which we call the de Broglie-Einstein-Rosen wave. Some properties of this exact solution are also discussed.
Structural, electronic, and optical properties of Zn-doped V2O5 thin films
Authors: Ikhlaq Uzma , Sami Samiullah , Khalil Maria , Ullah Farman , Ramay Shahid M , Ali Shahzad Akhtar , Saleem Murtaza 
Published: August 2024

Abstract
V2O5 shows a diverse range of applications due to its remarkable electronic and optical properties. This research is designed to tune the electronic and optical properties of V2O5 through modification in the energy band profile by varying Zn doping concentration. Density functional theory (DFT) calculations were used to investigate the Density of States (DOS) spectra for pure V2O5, exhibiting the prominent contribution of V-d and O-p orbitals, representing the p-d hybridized orbitals along with additional Zn-d orbital contribution in Zn-doped compositions. The effects of doping on the structural, morphological, elemental, and optical properties of the developed thin films were investigated employing x-ray diffraction (XRD), scanning electron microscope (SEM), x-ray dispersive spectroscopy (EDX), and spectroscopic ellipsometry (SE), respectively. x-ray diffraction analysis revealed the orthorhombic crystal structure in thin films. Surface morphology depicts the uniformly distributed compact rod-like features. The experimentally calculated band gap was found to decrease with Zn doping from 2.77 eV for pure V2O5 to 2.45 eV for maximum doping content. A significant variation is recorded in optical parameters like the increase in absorption coefficient and optical conductivity, which makes these more favorable for optoelectronic devices, particularly focusing on photovoltaics.
An improved YOLOv8 model enhanced with detail and global features for underwater object detection
Authors: Zhai Zheng-Li , Niu Niu-Wang-Jie , Feng Bao-Ming , Xu Shi-Ya , Qu Chun-Yu , Zong Chao 
Published: August 2024

Abstract
Underwater object detection is significant for the practical research of mastering existing marine biological resources. In response to the challenges posed by complex underwater environments such as water scattering and variations in object scales, researchers have developed YOLOv8 for object detection, driven by the rising popularity and iteration of deep learning. Building upon this model, we propose an enhanced underwater object detection model named YOLOv8-DGF. Firstly, we replace the convolutional layers of Spatial Pyramid Pooling Fusion (SPPF) with Invertible Neural Networks to further augment the fusion capacity of detailed features, facilitating the preservation of pivotal information while mitigating the impact of noise. Additionally, we introduce a global attention mechanism into Convolution to Fully Connected (C2f), which weights the input features, thereby emphasizing or suppressing feature information from different locations. Through our ‘Detail to Global’ strategy, the model achieved mAP@0.5 scores of 87.7% and 84.8% on the RUOD and URPC2020 datasets, respectively, with improved processing speed. Extensive ablation experiments on the Pascal VOC dataset demonstrate that YOLOv8-DGF outperforms other methods, achieving the best overall performance.
Observation of dielectric anomaly at magnetic transition temperature in NdMn1xZnxO3/SNTO (x = 0.00, 0.05, 0.10) films
Authors: Vyas Brinda , Ravalia Ashish , Udeshi Malay , Kuberkar D G 
Published: August 2024

Abstract
We report our observation of dielectric anomaly from temperature–dependent dielectric study near the antiferromagnetic transition (TN) in pure and Zn–doped NdMnO3/SNTO (SrNb0.002Ti0.998O3) epitaxial films. Structural and microstructural studies showed the presence of compressive strain along the a–axis and changes in grain size due to Zn–substitution. The variation in the elemental concentration of Zn was confirmed by RBS measurements led to amend Mn–Mn exchange interactions in doped films. Alteration in TN due to Zn–doping, obtained from D.C. magnetization is consistent with the dielectric anomaly temperatures, indicating the presence of magnetoelectric effect in pure and Zn–doped NdMnO3/SNTO system.
Noether symmetries and conservation laws in some analytic spherically symmetric spacetimes of f(R, L

m
) gravity
Authors: Dalal Preeti , Singh Karanjeet , Kumar Sachin , Malik Sandeep 
Published: August 2024

Abstract
In general relativity, dark energy is usually illustrated by a cosmological constant(Λ), but f(R, L

m
) gravity provides a different approach to cosmic acceleration by modifying the gravitational theory. In the present paper, the non-static spherically symmetric spacetimes have been derived by taking into account f(R, L

m
) = f
1(R) + H(L

m
)f
2(R). Lie symmetry approach is operated to reduce the order of the partial differential equations corresponding to the field equations, which are further solved. Killing and Noether symmetries provides insights into the conservation laws. So, the obtained spacetimes have been investigated to obtain the Killing and Noether symmetries. The Lagrangian approach have been used to obtain the Noether symmetries. This study is well-structured, as it provides a justification for the well-established result that Noether symmetries encompass Killing symmetries [1]. Also the conserved quantities and commutators of Noether symmetries have been calculated.
CMB spectral distortions from enhanced primordial perturbations: the role of spectator axions
Authors: Putti Margherita , Bartolo Nicola , Bhattacharya Sukannya , Peloso Marco 
Published: August 2024

Abstract
Primordial scalar and tensor modes can induce Cosmic Microwave Background spectral distortions during horizon re-entry. We investigate a specific mechanism proposed for this purpose, characterized by the coupling of an SU(2) gauge field to an axion undergoing a momentary stage of rapid evolution during inflation. Examining in details the perturbations produced by this model, we find that spectral distortions from the scalar modes significantly dominate those arising from the tensors. This holds true also for an earlier version of the model based on a U(1) gauge field. The scalar-induced distortions might be observed in future experiments, and the current COBE/FIRAS constraints already limit the parameter space of these models. Additionally, we find that delaying the onset of fast roll in the SU(2) scenario (to enhance the modes at the scales relevant for spectral distortions, while respecting the CMB constraints at larger scales) poses a greater challenge compared to the U(1) case. We propose a way to control the axion speed by varying the size of its coupling to the gauge fields.
String theory and the first half of the universe
Authors: Apers Fien , Conlon Joseph P. , Copeland Edmund J. , Mosny Martin , Revello Filippo 
Published: August 2024

AbstractWe perform a detailed study of stringy moduli-driven cosmologies between the end of inflation and the commencement of the Hot Big Bang, including both the background and cosmological perturbations: a period that can cover half the lifetime of the universe on a logarithmic scale. Compared to the standard cosmology, stringy cosmologies with vacua that address the hierarchy problem motivate extended kination, tracker and moduli-dominated epochs involving significantly trans-Planckian field excursions. We analyse the cosmology within the framework of the Large Volume Scenario but explain how analogous cosmological features are expected in other string theory models characterized by final vacua located in the asymptotic regions of moduli space. Conventional effective field theory is unable to control Planck-suppressed operators and so such epochs require a stringy completion for a consistent analysis. Perturbation growth in these stringy cosmologies is substantially enhanced compared to conventional cosmological histories. The transPlanckian field evolution results in radical changes to Standard Model couplings during this history and we outline potential applications to baryogenesis, dark matter and gravitational wave production.
Toward Exoplanet Transit Spectroscopy Using JWST/MIRI’s Medium Resolution Spectrometer
Authors: Deming Drake , Fu Guangwei , Bouwman Jeroen , Dicken Daniel , Espinoza Nestor , Glasse Alistair , Greene Thomas , Kendrew Sarah , Law David , Lustig-Yaeger Jacob , Garcia Marin Macarena , Schlawin Everett 
Published: August 2024

Abstract
The Mid-Infrared Instrument Medium Resolution Spectrometer (the MRS) on JWST has potentially important advantages for transit and eclipse spectroscopy of exoplanets, including lack of saturation for bright host stars, wavelength span to longward of 20 µm, and JWST’s highest spectral resolving power. We here test the performance of the MRS for time series spectroscopy by observing the secondary eclipse of the bright stellar eclipsing binary R Canis Majoris. Our observations push the MRS into saturation at the shortest wavelength, more than for any currently known exoplanet system. We find strong charge migration between pixels that we mitigate using a custom data analysis pipeline. Our data analysis recovers much of the spatial charge migration by combining detector pixels at the group level, via weighting by the point-spread function. We achieve nearly photon-limited performance in time series data at wavelengths longward of 5.2 µm. In 2017, Snellen et al. suggested that the MRS could be used to detect carbon dioxide absorption from the atmosphere of the temperate planet orbiting Proxima Centauri. We infer that the relative spectral response of the MRS versus wavelength is sufficiently stable to make that detection feasible. As regards the secondary eclipse of this Algol-type binary, we measure the eclipse depth by summing our spectra over the wavelengths in four channels, and also measuring the eclipse depth as observed by TESS. Those eclipse depths require a temperature for the secondary star that is significantly hotter than previous observations in the optical to near-IR, probably due to irradiation by the primary star. At full spectral resolution of the MRS, we find atomic hydrogen recombination emission lines in the secondary star, from principal quantum levels n = 7, 8, 10, and 14.
Wide Post-common Envelope Binaries from Gaia: Orbit Validation and Formation Models
Authors: Yamaguchi Natsuko , El-Badry Kareem , Rees Natalie R. , Shahaf Sahar , Mazeh Tsevi , Andrae Renŕ 
Published: August 2024

Abstract
Astrometry from Gaia DR3 has enabled the discovery of a sample of 3000+ binaries containing white dwarfs (WD) and main-sequence (MS) stars in relatively wide orbits, with orbital periods P
orb = (100–1000) days. This population was not predicted by binary population synthesis models before Gaia and—if the Gaia orbits are robust—likely requires very efficient envelope ejection during common envelope evolution (CEE). To assess the reliability of the Gaia solutions, we measured multi-epoch radial velocities (RVs) of 31 WD+MS binary candidates with P
orb = (40–300) days and AstroSpectroSB1 orbital solutions. We jointly fit the RVs and astrometry, allowing us to validate the Gaia solutions and tighten constraints on component masses. We find a high success rate for the Gaia solutions, with only 2 out of the 31 systems showing significant discrepancies between their Gaia orbital solutions and our RVs. Joint fitting of RVs and astrometry allows us to directly constrain the secondary-to-primary flux ratio

S

, and we find

S
≲
0.02

for most objects, confirming the companions are indeed WDs. We tighten constraints on the binaries’ eccentricities, finding a median e ≈ 0.1. These eccentricities are much lower than those of normal MS+MS binaries at similar periods, but much higher than predicted for binaries formed via stable mass transfer. We present MESA single and binary evolution models to explore how the binaries may have formed. The orbits of most binaries in the sample can be produced through CEE that begins when the WD progenitor is an AGB star, corresponding to initial separations of 2–5 au. Roughly 50% of all post-common envelope binaries are predicted to have first interacted on the AGB, ending up in wide orbits like these systems.
Neural subspaces of imagined movements in parietal cortex remain stable over several years in humans
Authors: Bashford L , Rosenthal I A , Kellis S , Bjånes D , Pejsa K , Brunton B W , Andersen R A 
Published: August 2024

Abstract

Objective. A crucial goal in brain–machine interfacing is the long-term stability of neural decoding performance, ideally without regular retraining. Long-term stability has only been previously demonstrated in non-human primate experiments and only in primary sensorimotor cortices. Here we extend previous methods to determine long-term stability in humans by identifying and aligning low-dimensional structures in neural data. Approach. Over a period of 1106 and 871 d respectively, two participants completed an imagined center-out reaching task. The longitudinal accuracy between all day pairs was assessed by latent subspace alignment using principal components analysis and canonical correlations analysis of multi-unit intracortical recordings in different brain regions (Brodmann Area 5, Anterior Intraparietal Area and the junction of the postcentral and intraparietal sulcus). Main results. We show the long-term stable representation of neural activity in subspaces of intracortical recordings from higher-order association areas in humans. Significance. These results can be practically applied to significantly expand the longevity and generalizability of brain–computer interfaces.
Clinical Trials
NCT01849822, NCT01958086, NCT01964261
Analysis and structural optimization of tree-type dynamic pressure groove mechanical seal performance
Authors: Wu Zechen 
Published: August 2024

Abstract
This study investigates the influence of the order and groove ratio of a tree-shaped groove on the sealing performance of a mechanical seal system using numerical simulations. A three-dimensional geometric model of the tree-shaped groove is established using SOLIDWORKS, and the mesh is divided in ANSYS Meshing before being imported into Fluent software for analysis. The single-factor experimental method is employed to evaluate the impact of different parameters on the opening force and leakage rate by varying one parameter while keeping others constant. The simulation results reveal that in the low-speed range, the tree-shaped groove with a groove ratio of 3:4:5 exhibits a larger opening force. Conversely, in the high-speed range, the three-stage tree-shaped groove with a groove ratio of 1:1:1 demonstrates a lower leakage rate and a larger opening force. The findings highlight the significant impact of the order and groove ratio of the tree-shaped groove on the sealing performance of the non-contact mechanical seal. The three-stage tree-shaped groove outperforms the second and fourth stages in terms of mechanical sealing performance, particularly in regard to the opening force. This study provides valuable insights into optimizing the design of tree-shaped grooves in mechanical seal systems to enhance their overall performance and efficiency.
Rolling bearing fault detection method based on teager energy operator
Authors: Zhou Jie 
Published: August 2024

Abstract
This study presents a method for detecting subtle faults in rolling bearings by integrating singular value decomposition (SVD) and local modal decomposition (LMD). Initially, the original vibration signals undergo reconstruction in phase space and subsequent denoising using SVD. Following this, LMD is employed to generate multiple local modal functions (IMFs), with the most sensitive IMF components selected based on kurtosis-mean square deviation criteria. The Teager energy operator (TEO) is then computed for these selected IMFs. Ultimately, Fourier transform analysis of TEO is utilized to identify faults in the inner and outer races of rolling bearings. Test results conducted on publicly available data from Case Western Reserve University validate the accurate identification of inner and outer race faults using this approach.
Valve positioner control based on active disturbance rejection control technology
Authors: Ding Yike , Wang Na , Sun Zhibo , Shang Xiaolei , Rui Shuwang , Wang Zhongdi 
Published: August 2024

Abstract
The pneumatic regulating valve is a commonly used actuator in industrial settings. The smart valve positioner, acting as the “brain” of the pneumatic regulating valve, dictates the control performance of the regulating valve, primarily relying on control algorithms. However, the valve positioner is a typical nonlinear system, making it difficult to establish an accurate mathematical model that can reflect the system’s nonlinear characteristics. Furthermore, due to variations in valves, installations, and processes, the model parameters differ significantly, making it challenging to self-adjust the parameters. Additionally, various disturbances in process control will affect the positioner’s control performance. Currently, commonly used control algorithms rely on precise mathematical models, resulting in poor control performance and robustness. Therefore, this article proposes a smart valve positioner control algorithm based on self-disturbance control. Initially, a steady-state model and system identification of the valve positioner system are obtained through open-loop testing, resulting in a simplified second-order system model. Based on the simplified second-order model, a second-order self-disturbance control algorithm is designed. Finally, a test platform based on the rapid control prototype (RCP) controller is established to verify that the introduction of the self-disturbance control algorithm can effectively enhance the control performance and robustness of the smart valve positioner.
Thermostatic interaction analysis of electric wheel brakes
Authors: Yan Yan , Wang Wenzhe , Cao Liangqiang , Hang Peng , Fu Xianlan , Huang Tao 
Published: August 2024

Abstract
The electric wheel needs to integrate the hub motor and brake in the wheel hub, so the integration scheme and structural parameters of each component in the electric wheel determine whether the electric wheel can coordinate the operation and the quality of the running performance. In this paper, the thermosolid interaction analysis of the brakes of electric wheels is carried out through ABUQUS software, so as to judge that the performance of the brakes meets the requirements, which will play a decisive role in the safety performance and life limit of the automobile, so as to effectively improve the working stability of electric wheels.
Research on agricultural monitoring and progressive map creation in the context of ground-air coordination
Authors: Li Xiaoyong 
Published: August 2024

Abstract
By combining network RTK technology, 2D LiDAR, and UAV, this study investigates how to achieve agricultural monitoring effectively. A collaborative agricultural monitoring scheme was designed to accurately and comprehensively gather agricultural information in response to the demand for targeted sequential monitoring at specified agricultural locations. To establish a low-cost and low computational power-dependent 3D map of obstacle point clouds, a progressive 3D mapping scheme based on 2D LiDAR was designed and implemented. The effectiveness of the design was validated through simulation experiments and partly through real-world testing.
GNSS location error reduction method for microtremor survey system based on EMD-CNN-LSTM
Authors: Wu Wei , Mou Xingang 
Published: August 2024

Abstract
Large errors exist when the microtremor survey system uses the global navigation satellite system (GNSS) for static localization. Aiming at the problem that the existing methods cannot effectively weaken the random error and multipath error, an error weakening method based on Empirical Mode Decomposition (EMD), Convolutional Neural Networks (CNN), and Long Short-term Memory Networks (LSTM) is proposed. The model first uses EMD to decompose the high-frequency random error, then reconstructs the low-frequency component and extracts the local features using CNN, and finally learns the change rule of multipath error using LSTM and weakens it. The model can remove random errors in the early stage while reducing the interference of noise on the neural network in the later stage and then improve the accuracy of localization. The experimental results show that the model can effectively improve the localization accuracy in the case of short-time measurements so that the localization accuracy in the E, N, and U directions can be improved by 74.57%, 74.76%, and 71.86%, respectively, which is more than 10% higher than the localization accuracy improvement rate of the existing CNN-LSTM model.