bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hollow ion atomic structure and X-ray emission in dense hot plasmas
Authors: Rosmej Frank B. , Fontes Christopher J. 
Published: September 2024

Hollow ion X-ray emission is of great interest in high-energy-density research, since negligible opacity allows studies from the interior of very dense objects. In this paper, ionization potential depressions of the isoelectronic sequences for single and double K-shell vacancies are obtained from a pure ab initio multiconfiguration Hartree–Fock simulation including exact exchange terms and finite temperature dense plasma effects. It is demonstrated that the simultaneous representation of these ab initio data in the form of a map of hollow ion X-ray transition energies enables identification of important steps in the matter evolution and ionization dynamics. Mapping along the isoelectronic sequence as a function of the pumping energy of a X-ray free electron laser also enables visualization of the impact of ionization potential depression on the pathways of hollow ion formation.
Inertia in relativistic mechanics
Authors: Germano Massimo 
Published: September 2024

Abstract
A general and explicit expression for inertia of a body of mass m in special relativity is given, valid for all the cases, as a function of mass, velocity modulus and angle between applied force and velocity vectors. An expression containing the total energy E in the determination of inertia is also obtained. This could be useful to clarify to students the actual role of mass and energy in the definition of the concept of inertia, connecting the two different contexts of Newtonian and relativistic mechanics.
Feynman's puzzle and the twins: applying the equivalence principle and the red shift
Authors: Derbes David 
Published: September 2024

Abstract
Two puzzles, one not well known and one notorious, are answered exactly and in an elementary fashion with the help of the gravitational red shift and the equivalence principle. The first is Feynman’s question: What motion maximizes the time recorded by a clock moving vertically, if it leaves the Earth and returns at a fixed terrestrial time? The second is the supposed inconsistency in the ages of two twins reunited after one has made a round trip at relativistic speed to a distant star.
Addendum: Multichannel quantum defect theory of strontium bound Rydberg states (2014 J. Phys. B: At. Mol. Opt. Phys. 47 155001)
Authors: Vaillant C L , Jones M P A , Potvliege R M 
Published: September 2024

Abstract
Newly calculated multichannel quantum defect theory parameters and channel fractions are presented for the singlet and triplet S, P and D series and singlet F series of strontium. These results correct those reported in Vaillant et al (2014 J. Phys. B: At. Mol. Opt. Phys.
47 155001).
Exploring the influence of plasma temperature on the evolution of boron molecular species in laser-induced plasma
Authors: Mohan Anandhu , Banerjee Anannya , Sarkar Arnab 
Published: September 2024

Abstract
The impact of plasma temperature on the formation and evolution of distinct and unique molecular species recorded as molecular signatures from laser induced plasma (LIP) was examined in this study. A definitive correlation between plasma temperature and the formation of molecular species has been established through a comprehensive temporal analysis of BO and BO2 molecular bands. The utilization of the signal-to-envelope ratio diagrams allowed for pinpointing the optimal temperature range for molecule emission. Notably, the molecule BO exhibited an ideal temperature range of 10,000–11,000 K for the proper formation of molecular emission bands, while BO2 preferred temperatures between 8,000–9,000 K. These optimal temperature ranges remained consistent regardless of the laser irradiation wavelength or ambient gas conditions of Ar, air or He studied in this work. These key findings highlight the significant influence of plasma temperature in shaping the molecular species observed in LIP.
Curing deformation compensation in bonding assembly for high-precision linear displacement encoder sensors
Authors: Yang Hongfan , Wang Jiayi , Xia Huanxiong , Liu Jianhua , Ao Xiaohui , Liu Xin , Li Da , Wang Yuhe 
Published: September 2024

Abstract
Linear displacement encoder sensors extensively appear in high-precision instruments, in which the core scale is usually bonded with the scale base by adhesives. However, the curing shrinkage of the adhesives often causes a warping deformation of the moving ruler, which in turn leads to a decrease in measurement accuracy. To improve the accuracy of the bonding assembly, this paper proposes a novel deformation compensation method. A force control fixture is first designed, and a tensile force is applied to tense the scale base. The scale is then bonded to the scale base, and the tensile force is maintained until the adhesive is cured. The optimal tensile force is determined to minimize the warping deformation by combining a finite-element simulation and an artificial fish swarm algorithm. The optimal result is verified experimentally, where the warping deformation is measured using a homemade three-dimensional digital image correlation system. The experimental results demonstrate that the warping deformation of the moving ruler is reduced by 89.2% using the proposed method.
Dual-channel feature extraction hybrid attention network for detecting infrared small targets
Authors: Nie Suzhen , Cao Jie , Miao Jiaqi , Hou Haiyuan , Hao Qun , Zhuang Xuye 
Published: September 2024

Abstract
For military early warning, forest fire prevention, and maritime search and rescue, infrared small target detection is critical. However, because of the low contrast and inconspicuous features of infrared small targets, rendering most existing methods ineffective in restoring target edge details or misidentifying the background as a target. This paper proposes a dual-channel feature extraction network (DCFE-Net) with hybrid attention, which enables the network to suppress the background and enhance the target by designing dual-channel feature extraction and multi-layer feature fusion. Specifically, the dual-channel mainly consists of a convolutional attention fusion module, which adaptively integrates feature map correlations by introducing a hybrid attention module to capture global information while enhancing the feature representation of small targets, and a feature compression extraction module, which utilizes depth-separable convolutional combinations to carry out fine-grained target feature extraction while reducing the loss of details. In addition, the multilevel feature enhancement module ensures that the network can capture targets at different scales through skip connection operations, while avoiding small targets from being overwhelmed by deep features, making them simultaneously semantically informative and detailed. Therefore, the network can fuse multilevel features for effective information extraction. According to the experimental results, DCFE-Net performs best in false alarm rate and detection probability.
Assessment of the relational strength between triggers detected in physiological signals and the occurrence of atrial fibrillation episodes
Authors: Pluščiauskaitė Vilma , Sološenko Andrius , Jančiulevičiūtė Karolina , Marozas Vaidotas , Sörnmo Leif , Petrėnas Andrius 
Published: September 2024

Abstract

Objective. Despite the growing interest in understanding the role of triggers of paroxysmal atrial fibrillation (AF), solutions beyond questionnaires to identify a broader range of triggers remain lacking. This study aims to investigate the relation between triggers detected in wearable-based physiological signals and the occurrence of AF episodes. Approach. Week-long physiological signals were collected during everyday activities from 35 patients with paroxysmal AF, employing an ECG patch attached to the chest and a photoplethysmogram (PPG)-based wrist-worn device. The signals acquired by the patch were used for detecting potential triggers due to physical exertion, psychophysiological stress, lying on the left side, and sleep disturbances. To assess the relation between detected triggers and the occurrence of AF episodes, a measure of relational strength is employed accounting for pre- and post-trigger AF burden. The usefulness of ECG- and PPG-based AF detectors in determining AF burden and assessing the relational strength is also analyzed. Main results. Physical exertion emerged as the trigger associated with the largest increase in relational strength for the largest number of patients (p < 0.01). On the other hand, no significant difference was observed for psychophysiological stress and sleep disorders. The relational strength of the detected AF exhibits a moderate correlation with the relational strength of annotated AF, with r = 0.66 for ECG-based AF detection and r = 0.62 for PPG-based AF detection. Conclusions. The findings indicate a patient-specific increase in relational strength for all four types of trigger. Significance. The proposed approach has the potential to facilitate the implementation of longitudinal studies and can serve as a less biased alternative to questionnaire-based AF trigger detection.
Materials & design approaches for enhanced performance of mechanically compliant thermoelectric generators (TEGs): a review
Authors: Daraghma H S , Ferry D B , Rao S G , Hawwa M A , Gondal M A , Rojas J P 
Published: September 2024

Abstract
In the pursuit of sustainable solutions to the ever-increasing demand for renewable energy, mechanically compliant thermoelectric generators (TEGs) have garnered significant attention owing to the promise they present for application in generating power from waste heat in mechanically challenging scenarios. This review paper examines the ongoing advancements in the efficiency and applicability of TEGs through novel material engineering and design innovations. It delves into the improvement of their thermoelectric (TE) properties via micro- and nanostructural modifications and explores architectural advancements aimed at enhancing functionality and power output. Notably, the integration of TEGs into flexible, stretchable, and wearable electronics has been a significant development, expanding their applications in various domains such as healthcare monitoring, remote sensing, and consumer electronics. The review emphasizes the critical interplay between electronic, thermal, and mechanical aspects in optimizing TEGs performance. By providing an in-depth exploration of these multifaceted interactions and highlighting the significant advancements in materials and design, this review aims to underscore the importance of TEGs in a cleaner and more efficient era of energy generation, with a particular focus on their emerging applications across diverse fields.
Nonlinear vibration of a loaded string in energy harvesting
Authors: Liu Tao , Zhao Chaoyang , Yang Yaowen , Yuan Weifeng 
Published: September 2024

Abstract
Designing wideband energy harvesters using beam structures typically involves complexities, particularly in low-frequency and low-energy environments where the limitations of beam structures become more evident. To address these challenges, this study proposed a strategy for energy harvesting using a loaded-string system and established a theoretical model to investigate its performance. A parametric study was conducted for the string system, examining the effects of initial tension, mass location, material stiffness and excitation amplitude. The accuracy of the proposed model was verified through experimental validation. Both theoretical and experimental analyses observed a frequency shifting phenomenon, demonstrating the wideband characteristics of the system. Furthermore, the proposed string structure allows for convenient parameter adjustments, enabling the tuning of its natural frequency and operating bandwidth to meet more stringent practical requirements. The string system provides a new direction for designing energy harvesters to harness low-frequency energy from the ambient environment.
Thirring universe model
Authors: Yılmaz Nazmi , Akıllı Mahmut , Akdeniz K G 
Published: September 2024

Abstract
In recent years, there has been a significant amount of research focused on Thirring instantons. This study aims to employ the Thirring quantum model as a theoretical Universe model to gain a more profound understanding of the beginning of the Universe. For this, we propose to analyze the entropy of the quantum states of zero energy Thirring instanton solutions and the transition to other quantum states. Our findings by also using Lyapunov exponents and the cyclic attractors as comparative nonlinear methods show that there is no entropy corresponding to instanton solutions with zero energy and that the sudden increase in entropy indicates the formation of the Universe. We evaluate the implications of this study in terms of the standard Universe model. Thus we anticipate that these results have the potential to contribute significantly to our understanding of the origin of the Universe and highlight the role of chaos and complexity in its evolution.
Effect of Dy3+ ions on physical, structural and thermal properties of ZnNaPbB glasses
Authors: Manjeet  , Anu  , Deopa Nisha , Kumar Anand , Chahal Rishi Pal 
Published: September 2024

Abstract
In this report, inspired by the excellent spectroscopic characteristics of dysprosium (Dy3+) ions doped borate glasses, a series with the composition (70-x)B2O3-10ZnO-10PbO-10Na2CO3-xDy2O3 (here ‘x’ have the values as 0.1, 0.5, 1.0, 1.5 and 2.0 in mol % ) was made using the melt quenching process and named as ZnNaPbBDy0.1 to ZnNaPbBDy2.0. Here we study the physical, structural and thermal properties of Dy3+ ions doped Zinc Sodium Lead Borate (ZnNaPbB) glasses through different characterization techniques like Fourier transform infrared (FT-IR), Raman spectroscopy, Differential scanning calorimetry (DSC) and decay spectroscopy. Several physical parameters were evaluated to assess the effect of Dy3+ inclusion. FT-IR and Raman spectra confirm the presence of BO3 and BO4 structural units. The data recorded by DSC spectra have been used to predict the glass transition temperature (Tg). The nature of decay spectra was estimated which diverges from exponential to non-exponential at higher concentrations. The decay spectral data is used to calculate the experimental lifetimes for all the glass samples. The Inoakutti Hirayama (I-H) model and Dexter’s plot are used to confirm the type of interaction between the donor and acceptor Dy3+- Dy3+ ions is dipole–dipole in nature that is responsible for the emission intensity quenching with concentration. All the above results might be advantageous for variety of applications in photonic devices.
Design and analysis of circular sheet junctionless double gate vertical nanotube (CSJL-DG-VNT) FET for DC/Analog/RF applications: device to circuit implementation
Authors: Bhukya Sunitha , Nistala Bheema Rao 
Published: September 2024

Abstract
This paper investigates the influence of geometrical variations on the performance characteristics of a novel circular sheet junctionless double gate vertical nanotube (CSJL-DG-VNT) FET through 3D numerical simulations at sub-5nm technology node. Initially, the proposed device is compared with NWFET and NSFET, and shown favourable performance. The ION/IOFF current ratio is improved to 51.9% when gate length (Lg) is sweeping from 8 nm to 12 nm. The decrease in L

g
leads to enhanced analog/RF metrics such as gm, gm/Id, and fT. It was observed that opting for the shortest L

g
may be advantageous for certain parameters, albeit at the expense of others, depending on the specific application requirements. Further, while maintaining a constant L

g
, variations in the thickness tNT from 5 to 10 nm were carried out to evaluate the analog/RF performance for device optimization. It was observed that lower tNT (5 nm) values yielded improved IOFF current around ∼ 2 order and DIBL is 32.77% when compared with higher tNT (10 nm) due to ameliorated channel control from both inner and out gate of VNT. Subsequently, at an optimal L

g
and t

NT
the temperature (T) varied from 250 K to 450 K to analyze the device characteristics, indicating that a lower T should be favoured. Furthermore, the device is used for designing a common-source (CS) amplifier with tNT variations and noticed that at 5 nm of t

NT
outperforms highest gain (AV) ∼ 6.8 V/V when compared to 7 nm and 10 nm.
Static, cylindrically symmetric spacetime in the coincident f(Q) gravity
Authors: Kirezli Pınar , Özceylan Nilhan 
Published: September 2024

Abstract
In this paper we consider a static, cylindrically symmetric spacetime with coincident f(Q) gravity. Since the field equation of this spacetime in symmetric teleparallel gravity is suitable for choosing the function of f(Q) in the form of power series and exponential forms which are in coherent with cosmological observations, anisotropic perfect fluid solutions of these forms are discussed for this spacetime. Energy densities, directional pressures and energy conditions are plotted and analysed for a few different metric potentials. Although corresponding cosmic strings violate all energy conditions in both f(Q) functions, the corresponding Levi-Civita solution violates all energy conditions in the power law function of f(Q), but for exponential f(Q) gravity they are satisfied in small regions.
Λ

6

He

(1−, 2−) spin doublet in a Λ + n + α cluster model
Authors: Meoto E F , Lekala M L , Ojukwu E C 
Published: September 2024

Abstract
The spin singlet and spin triplet states of the helium-6-lambda hypernucleus are studied in configuration space as a three-body problem, using the hyperspherical method. This hypernucleus is treated as a Λ + n + α cluster model. Since the α particle core has a spin of 0, this is an ideal hypernucleus from which to understand spin dependence in hyperon-nucleon potentials. In this paper, the hyperon-nucleon potential considered is the GLM-YN0 Λ-n potential, which is a simulation of the NSC97f potential obtained through inverse scattering theory. Due to violations of the cluster structure, two-body potentials underbind the helium-6-lambda hypernucleus. This issue is addressed by including a three-body force to complement these two-body forces. A three-body force, whose strength is spin dependent, is used to guide predictions of the spin triplet state of helium-6-lambda which is not yet known experimentally.
Dynamics of thermal radiatively Jeffrey fluid through an annulus region between two flexible tubes with entropy generation
Authors: Fayyaz A , Abbas Z , Rafiq M Y 
Published: September 2024

Abstract
Endoscope is a very important tool for medical diagnosis and they have many clinical applications. The endoscope now is a very important tool used for determining real reasons responsible for many problems in the human organs in which the fluid is transported by peristaltic pumping such as the stomach, small intestine, etc Therefore, this paper discusses the influence of an endoscope on the peristaltic flow of a Jeffery fluid in an annulus by considering the entropy generation. The inner tube which is uniform and rigid fulfilled the slip conditions, while the outer tube having a sinusoidal wall has a no-slip condition. The impacts of thermal radiation and viscous dissipation are also considered in the energy equation. The flow analysis has been developed for low Reynolds number and long wavelength approximation. The analytical solution for velocity, pressure gradient, temperature, streamlines, entropy generation, and Bejan number is obtained using the perturbation method, and then the obtained results are plotted to see the influence of different physical parameters. The major outcomes disclosed that the velocity profile decreases near the region of the inner tube due to the slip parameter and the inner tube radius. However, it increases due to the inner tube velocity and amplitude ratio. The temperature distribution rises with the Brinkman number. On the other hand, it declined for the radiation parameter. Furthermore, the entropy generation increases for the Brinkman number, but the Bejan number decreases for the Brinkman number. The present study has application in endoscopes, which is important to diagnose problems in internal organs. Also, the variation of pressure gradient helps to maintain the flow rate which is essential during the insertion of the catheter into the artery.
Luminescence and dielectric investigations of crystalline niobate nanoceramics prepared through aqueous chemical process
Authors: Sarkar Kakali , Kumar Vivek 
Published: September 2024

Abstract
The present study reflects the synthesis of MgNb2O6 using hydrofluoric acid via a wet chemical approach, followed by characterizations involving XRD, electron microscopy, Raman spectroscopy, optical analyses, and impedance spectroscopy. The crystallite size of the synthesized material was determined to be 44 nm through XRD analysis. The lattice parameters of MgNb2O6 a, b, and c, were found to be 14.1998 Å, 5.6844 Å, and 4.9813 Å, respectively. Raman spectroscopy identified molecular bonds ranging from 253 to 1011 cm−1, mainly indicating the presence of metal oxide bonds. EDX spectra confirmed the presence of Mg, Nb, and O atoms in the prepared ceramics, indicating phase purity. FESEM analysis revealed a grain size of approximately 48 nm, with the presence of agglomerated grains. Bright spots in the SAED pattern observed by HRTEM confirmed the crystallinity of the prepared niobate materials, with the HRTEM microstructure showing a particle size near 49 nm. The crystallite size by XRD, grain size by FESEM, and particle size by HRTEM are in accordance with each other. The direct band gap was determined to be approximately 2.76 eV using UV-Visible spectroscopy. Additionally, MgNb2O6 materials exhibited a broad and strong photoluminescence emission near 445 nm with excitation at 270 nm, possibly indicating the presence of radiative defects in the crystalline nanostructure. Furthermore, impedance studies conducted between 40 and 110 MHz demonstrated a decrease in the dielectric constant at higher frequencies, reaching 21.06 at 110 MHz. A low dielectric loss was also observed at 110 MHz. The moderate band gap and strong room-temperature photoluminescence in the visible range make magnesium niobates suitable for possible applications in optical devices. This investigation shows that a dielectric constant near 21 and low dielectric loss can be achieved in the high-frequency range around 110 MHz.
Phase-space representation of coherent states generated through SUSY QM for tilted anisotropic Dirac materials
Authors: O-Campa Daniel , Díaz-Bautista Erik 
Published: September 2024

Abstract
In this paper, we examine the electron interaction within tilted anisotropic Dirac materials when subjected to external electric and magnetic fields possessing translational symmetry. Specifically, we focus on a distinct non-zero electric field magnitude, enabling the decoupling of the differential equation system inherent in the eigenvalue problem. Subsequently, employing supersymmetric quantum mechanics facilitates the determination of eigenstates and eigenvalues corresponding to the Hamiltonian operator. To delve into a semi-classical analysis of the system, we identify a set of coherent states. Finally, we assess the characteristics of these states using fidelity and the phase-space representation through the Wigner function.