bluuebunny/crossref_metadata_2025 huggingface dataset:
Does the use of unusual combinations of datasets contribute to greater scientific impact?
Authors: Yu Yulin , Romero Daniel M.
Published: October 2024

Scientific datasets play a crucial role in contemporary data-driven research, as they allow for the progress of science by facilitating the discovery of new patterns and phenomena. This mounting demand for empirical research raises important questions on how strategic data utilization in research projects can stimulate scientific advancement. In this study, we examine the hypothesis inspired by the recombination theory, which suggests that innovative combinations of existing knowledge, including the use of unusual combinations of datasets, can lead to high-impact discoveries. Focusing on social science, we investigate the scientific outcomes of such atypical data combinations in more than 30,000 publications that leverage over 5,000 datasets curated within one of the largest social science databases, Interuniversity Consortium for Political and Social Research. This study offers four important insights. First, combining datasets, particularly those infrequently paired, significantly contributes to both scientific and broader impacts (e.g., dissemination to the general public). Second, infrequently paired datasets maintain a strong association with citation even after controlling for the atypicality of dataset topics. In contrast, the atypicality of dataset topics has a much smaller positive impact on citation counts. Third, smaller and less experienced research teams tend to use atypical combinations of datasets in research more frequently than their larger and more experienced counterparts. Last, despite the benefits of data combination, papers that amalgamate data remain infrequent. This finding suggests that the unconventional combination of datasets is an underutilized but powerful strategy correlated with the scientific impact and broader dissemination of scientific discoveries.
Current usage of sounding rockets to study the upper atmosphere
Authors: Heatwole Scott E.
Published: October 2024

Sounding rockets have played and continue to play a key role in the modeling of the upper atmosphere and predicting weather. Goddard’s insight into the usefulness of rockets for this application came at a time when measurements had not been made above the troposphere. Present-day developments in sounding rockets have allowed more elaborate experiments to make measurements with multiple rockets and ejected subpayloads allowing for in situ spatial and temporal measurements of the upper atmosphere, thus contributing to our understanding of both terrestrial weather and space weather.
Hopfion-like solutions in de Sitter spacetime
Authors: Grzela Adam , Jezierski Jacek , Smołka Tomasz
Published: October 2024

We construct electromagnetic field with non-trivial topological properties on de Sitter background. The field is closely related with Hopf fibration. We analyze energy, angular momentum and topological charges for this solution. The paper is a generalization of Smołka and Jezierski (2018 Class. Quantum Grav.
35 245010) to de Sitter spacetime.
Boosted Kerr–Newman black holes
Authors: Aranha Rafael F , Maier Rodrigo
Published: October 2024

In this paper we obtain a new solution of Einstein field equations which describes a boosted Kerr–Newman black hole relative to a Lorentz frame at future null infinity. To simplify our analysis we consider a particular configuration in which the boost is aligned with the black hole angular momentum. The boosted Kerr–Newman black hole is obtained considering the complete asymptotic Lorentz transformations of Robinson–Trautman coordinates to Bondi–Sachs, including the perturbation term of the boosted Robinson–Trautman metric. To verify that the final form of the metric is indeed a solution of Einstein field equations, we evaluate the corresponding energy–momentum tensor the boosted Kerr–Newman solution. To this end, we consider the electromagnetic energy–momentum tensor built with the Kerr boosted metric together with its timelike killing vector. We show that the Papapetrou field thus obtained engender an energy–momentum tensor which satisfies Einstein field equations up to 4th order for the Kerr–Newman metric. To proceed, we examine the causal structure of the boosted Kerr–Newman black hole in Bondi–Sachs coordinates as in a preferred timelike foliation. We show that the ultimate effect of a nonvanishing charge is to shrink the overall size of the event horizon and ergosphere areas when compared to the neutral boosted Kerr black holes. Considering the preferred timelike foliation we obtain the electromagnetic fields for a proper nonrotating frame of reference. We show that while the electric field displays a pure radial behavior, the magnetic counterpart develops an involved structure with two intense lobes of the magnetic field observed in the direction opposite to the boost.
Tractable optimal experimental design using transport maps*
Authors: Koval Karina , Herzog Roland , Scheichl Robert
Published: October 2024

We present a flexible method for computing Bayesian optimal experimental designs (BOEDs) for inverse problems with intractable posteriors. The approach is applicable to a wide range of BOED problems and can accommodate various optimality criteria, prior distributions and noise models. The key to our approach is the construction of a transport-map-based surrogate to the joint probability law of the design, observational and inference random variables. This order-preserving transport map is constructed using tensor trains and can be used to efficiently sample from (and evaluate approximate densities of) conditional distributions that are required in the evaluation of many commonly-used optimality criteria. The algorithm is also extended to sequential data acquisition problems, where experiments can be performed in sequence to update the state of knowledge about the unknown parameters. The sequential BOED problem is made computationally feasible by preconditioning the approximation of the joint density at the current stage using transport maps constructed at previous stages. The flexibility of our approach in finding optimal designs is illustrated with some numerical examples inspired by disease modeling and the reconstruction of subsurface structures in aquifers.
Editorial for two-dimensional materials-based heterostructures for next-generation nanodevices
Authors: Wang Guangzhao , Ang Yee Sin , Zhou Liujiang , Yuan Hongkuan
Published: October 2024

Heterostructures, such as van der Waals (vdW) heterostructures, provide a versatile platform for engineering the physical properties of two-dimensional (2D) layered materials, spanning electronics, mechanics, optics, as well as electron-phonon couplings. Furthermore, vdW heterostructures, which are composed of metal/semiconductor or semiconductor/semiconductor combinations, not only maintain the unique properties of their individual constituents but also exhibit tunable physical and chemical properties that can be externally adjusted through strain, heat, and electric fields. These externally tunable properties offer significant advances in the fields of solid-state devices and renewable energy applications. Additionally, 2D material-based heterostructures, such as those composed of 0D clusters or quantum dots, as well as 1D nanotubes/wires in combination with 2D materials, also show immense potential for advancing next-generation nanodevices. The vast design space of vdW heterostructures enables their versatile applications spanning numerous fields, such as light-emitting diodes, field-effect transistors, photocatalysis, solar cells, photodetectors, and so on. In the Special Issue of Journal of Physics: Condensed Matter, entitled ‘Two-dimensional Materials-based Heterostructures for Next-generation Nanodevices’, we have gathered a comprehensive collection of 14 articles, presenting the latest achievements in the fields of designing novel 2D materials and 2D heterostructures. Below, we have briefly condensed the essential research findings from these studies.
Superconducting density of states and vortex lattice of LaRu2P2 observed by scanning tunneling spectroscopy
Authors: Fernández-Lomana Marta , Aguilera Paula Obladen , Wu Beilun , Herrera Edwin , Suderow Hermann , Guillamón Isabel
Published: October 2024

We provide the superconducting density of states of the pnictide superconductor LaRu2P2 (Tc
= 4.1 K), measured using millikelvin scanning tunneling microscopy. From the tunneling conductance, we extract a density of states which shows the opening of a s-wave single superconducting gap. The temperature dependence of the gap also follows BCS theory. Under magnetic fields, vortices present Caroli de Gennes Matricon states, although these are strongly broadened by defect scattering. From the vortex core size we obtain a superconducting coherence length of ξ = 50 nm, compatible with the value extracted from macroscopic

H

c
2

measurements. We discuss the comparison between s-wave LaRu2P2 and pnictide unconventional multiple gap and strongly correlated Fe based superconductors.
ADS–SLAM: a semantic SLAM based on adaptive motion compensation and semantic information for dynamic environments
Authors: Dai Jun , Yang Minghao , Li Yanqin , Zhao Junwei , Hanajima Naohiko
Published: October 2024

Static environment assumptions are a prerequisite for simultaneous localization and mapping (SLAM), while interference from dynamic objects in the environment can seriously impair the system’s localization accuracy. Recently, many works have combined deep learning and geometric constraints to attenuate the interference of dynamic objects, but poor real-time performance and low accuracy in high dynamic scenes still exist. In this paper, we propose a semantic SLAM algorithm for complex dynamic scenes named ADS–SLAM. Our system combines the advantages of semantic information and motion constraints to remove dynamic points during tracking and localization. First, an adaptive dynamic point detection method based on epipolar constraint between adjacent frames is designed to adapt to the changes of object motion states and a motion area detection method based on Gaussian mixture model and Kalman Filter is utilized to effectively compensate the missed motion areas. Second, an object detection network with improved inference in the backend is utilized to extract prior object semantics. Lastly, the multi-level information is integrated in order to comprehensively screen all dynamic points in the environment and utilize only static points for pose estimation and optimization. Experimental evaluations on challenging public datasets and outdoor dynamic environments demonstrate that our algorithm achieves high localization accuracy in almost all dynamic scenarios compared to the current state-of-the-art SLAM algorithms, with the highest accuracy in high dynamic scenarios, and shows real-time performance for practical applications.
Deep spatial-temporal information fusion dynamic graph convolutional network for traffic flow prediction
Authors: Li Guoyan , Wang Wei , Wang Li , Liu Yi , Zhang Minghui
Published: October 2024

Predicting traffic flow is vital for advancing intelligent transportation systems, but achieving precise forecasts remains challenging. To deeply explore the complex and diverse dynamic spatio-temporal correlation of traffic data, this study proposes a information fusion spatio-temporal dynamic graph convolution model for traffic flow prediction. In the model construction, firstly, a dynamic graph generation module is designed to fully capture the complex spatial correlation of the traffic network and model the changing spatio-temporal interaction; secondly, the spatial self-attention mechanism is used to dynamically focus on the spatial relationship between different nodes, and combined with the dynamic graph convolution network to extract the spatial dynamic correlation features of the road network to study deep spatio-temporal information; Finally, existing models rarely consider other traffic information related to traffic flow, and a spatio-temporal information fusion module is designed to enhance the ability of the model to perceive information, thereby improving the performance of traffic flow prediction models. Experiments are conducted on four real traffic datasets using three performance evaluation metrics and 18 baseline models. The results show that the model has higher prediction accuracy.
CBS-YOLOv5: fault detection algorithm of electrolyzer plate with low-resolution infrared images based on improved YOLOv5
Authors: Liu Xiaoyi , Zhu Jianyu , Zhu Zhanyu , Zhu Hongqiu
Published: October 2024

In the process of copper electrorefining, accurate detection of electrode plate faults is extremely challenging due to the low resolution of captured infrared images, significant noise interference, and dense electrode plate arrangements. To address these challenges, this paper proposes an improved YOLOv5-based electrode plate fault detection algorithm called CBS-YOLOv5. This algorithm introduces several innovations over the original YOLOv5, including: the incorporation of coordinate attention to enhance the ability of the feature extraction network to separate target information from noise; the construction of a small object detection module to improve the detection of dense small objects by increasing the resolution of the feature map; the replacement of the traditional path aggregation network with a Bi-directional Feature Pyramid Network (BiFPN) for more flexible multi-scale feature fusion; and the integration of the swin transformer to optimize the cross-stage partial bottleneck structure, significantly enhancing the model’s ability to detect densely packed small objects. Experimental results show that the proposed CBS-YOLOv5 model achieves an accuracy of 88.1%, which is an improvement of 5.7% over the base model. Furthermore, this algorithm demonstrates exceptional detection capabilities for dense small objects in low-resolution infrared images while maintaining real-time detection speed, making it suitable for various complex industrial scenarios, including fault detection in non-ferrous metal electrolysis processes. CBS-YOLOv5 not only improves detection accuracy and robustness but also has broad application prospects, offering a new solution for intelligent manufacturing and industrial inspection.
A short-circuit protection scheme for active distribution networks based on improved adaptive current reliability coefficient
Authors: Sun Haoyue , Zhang Xinhui , Xu Honglu , Guo Aiyu , Xie Shuyu
Published: October 2024

Addressing the issue of misoperation in traditional three-zone current protection caused by the assisted, drawdown, or reverse current due to the large-scale integration of distributed generation (DG) into distribution networks (DNs), an adaptive current short-circuit protection scheme based on local information is proposed for active DNs (ADNs). Firstly, the adaptive current protection reliability coefficients are improved for the setting of protection zones I and II of the lines in the ANDs. On the DG side, an improved reliability coefficient is constructed using an e-exponential function. Subsequently, the distance between the fault point and the busbar is calculated by analyzing the relation between the positive-sequence voltage and positive-sequence current at the measuring point when faults occur at various locations. Based on this distance parameter, the reliability coefficient is adjusted in real time. Finally, the modified adjustable reliability coefficient, along with the online-calculated equivalent impedance and equivalent electromotive force, is used to coordinate the setting of short-circuit protection zones I and II of the lines in the ADNs. Simulation results demonstrate that, compared with traditional adaptive current protection schemes, this proposed scheme is independent of the location of short-circuit fault points, the grid-connected capacity, or the number of DGs, exhibiting better selectivity and reliability.
Device simulation study of multilayer MoS2 Schottky barrier field-effect transistors
Authors: He Zhuoyang , Yang HeeBong , Young Kim Na
Published: October 2024

Molybdenum disulfide (MoS2) is a representative two-dimensional layered transition-metal dichalcogenide semiconductor. Layer-number-dependent electronic properties are attractive in the development of nanomaterial-based electronics for a wide range of applications including sensors, switches, and amplifiers. MoS2 field-effect transistors (FETs) have been studied as promising future nanoelectronic devices with desirable features of atomic-level thickness and high electrical properties. When a naturally n-doped MoS2 is contacted with metals, a strong Fermi-level pinning effect adjusts a Schottky barrier and influences its electronic characteristics significantly. In this study, we investigate multilayer MoS2 Schottky barrier FETs (SBFETs), emphasizing the metal-contact impact on device performance via computational device modeling. We find that p-type MoS2 SBFETs may be built with appropriate metals and gate voltage control. Furthermore, we propose ambipolar multilayer MoS2 SBFETs with asymmetric metal electrodes, which exhibit gate-voltage dependent ambipolar transport behavior through optimizing metal contacts in MoS2 device. Introducing a dual-split gate geometry, the MoS2 SBFETs can further operate in four distinct configurations: p − p, n − n, p − n, and n − p. Electrical characteristics are calculated, and improved performance of a high rectification ratio can be feasible as an attractive feature for efficient electrical and photonic devices.
Post-irradiation darkening model for EBT-3 films characterized using a single lot calibration approach
Authors: Caprioli Marco , Delombaerde Laurence , De Roover Robin , Crijns Wouter
Published: October 2024

Objective. In this study, we present a model to correct the progressive post-irradiation darkening of EBT3 films. The model allows for a clinical use of EBT3 using application and calibration films scanned with different post-irradiation times. Approach. The model is a post-irradiation time- and dose-dependent power-law function, projecting the scanned transmittance of application films to the transmittance matching the same post-irradiation time of calibration films. The model was characterized for two EBT3 production lots within the dose range 0.1–12.8 Gy. A first characterization was performed utilizing calibration films scanned repeatedly for 54 d post-irradiation (lot 1), while a fast re-characterization of a second lot used three post-irradiation times (lot 2). For a long-term validation of the model, 16 film strips were irradiated at 2 Gy on different time points starting from the day of film calibration up to 43 d afterwards (lot 1). For the multiple-dose validation of the model, 8 strips were irradiated with dose levels ranging 0–12 Gy deposited 25 d after the calibration (lot 2). As a proof of principle, the model was applied to four clinical patient-specific quality assurance film measurements with prescribed dose/fraction ranging 2.66 Gy–8 Gy. Main results. The post-irradiation transmittance decreased for higher doses up to −2.5% at 12.8 Gy, and 54 d post-irradiation. With a lot-specific model correction, the mean dose accuracy of validation strips that ranged from initial −3.4% (triple-channel) and −9.90% (blue-channel) reduced to within 3.0% (all colour channels) for doses above 1 Gy. The median dose difference with the planned dose improved from −3.5% to −1.1%, and the 3%/2 mm local gamma ranged from (48.5–92.5)% to (81.2–99.2)%. Significance. A film darkening model corrects the transmittance of EBT3 films and increases the flexibility of existing dosimetry protocols. The correction ensures dose accuracies within 3%.
Magneto-acousto-electrical tomography based on frequency response compensated linearly frequency-modulated signal stimulation
Authors: Li Meijia , Wang Jianfei , Jia Kebin , Sun Zhishen
Published: October 2024

Objective. In magneto-acousto-electrical tomography (MAET), linearly frequency-modulated (LFM) signal stimulation uses much lower peak voltage than the spike pulse stimulation, lengthening the operation life of the transducer. However, due to the uneven frequency responses of the transducer, the low-noise amplifier (LNA), and the bandpass filter (BPF), MAET using LFM signal stimulation suffers from longitudinal resolution loss. In this paper, frequency response compensated linearly frequency-modulated (FRC-LFM) signal stimulation is investigated to resolve the problem. Approach. The physical model of measurement of the frequency responses of the transducer and the cascading module of the detection electrodes, the LNA, and the BPF is constructed. The frequency responses are approximated by fitting a curve to the measurement data. The frequency response compensation function is set to the reciprocal of the product of the frequency responses. The digital FRC-LFM signal is generated in MATLAB and converted to analog signal through an arbitrary waveform generator. Two groups of MAET experiments are designed to confirm the performance of the FRC-LFM signal stimulation. Pure agar phantom with rectangular through-holes and agar phantom with pork tissue inclusion serve as the samples. Main results. The pulse-compressed magneto-acousto-electrical signal obtained using FRC-LFM stimulation has narrower main-lobe than that obtained using LFM excitation, although the signal to noise pulse interference ratio of the former is little lower than that of the latter, which is due to the limitation of the power amplifier. FRC-LFM also proves to be an effective method to utilize the frequency outside the working band of the transducer in MAET. Significance. The method in this study compensates for the longitudinal resolution loss due to the uneven frequency responses. Combining with high-capability power amplifier and high-performance LNA, the MAET using FRC-LFM signal stimulation can potentially achieve high longitudinal resolution and high sensitivity, advancing MAET toward the clinical application.
A surface-shunting method for the prevention of a fault-mode-induced quench in high-field no-insulation REBCO magnets
Authors: Dong Fangliang , Park Dongkeun , Kim Junseong , Bascuñán Juan , Iwasa Yukikazu
Published: October 2024

In this paper, we apply a surface-shunting method to prevent quenches in no-insulation (NI) REBCO magnets triggered by external failures of magnet current leads or power suppliers (i.e. fault mode). In a high-field magnet system, an NI coil may still be at risk during the mentioned quench events even if the whole magnet is well-designed, non-defective, and properly operated. The mechanism of this fault-mode quench initiation and propagation still remains unclear, complicating the development of reliable quench protection. Here, we present this mechanism to demonstrate a corresponding practical quench-preventive approach named surface shunting, which utilizes a low-temperature solder attached to the top and bottom of pancake coils. We validate the effectiveness of this approach by comparing the electromagnetic, thermal, and mechanical behaviors in the fault mode with and without the shunt. We conclude that the surface shunt suppresses the fault-mode quench initiation and propagation by redirecting the original turn-to-turn current and induced overcurrent out of the NI winding. We anticipate this work can provide a solution to improve the operational safety of high-field high-temperature superconducting NI magnets against quench and potential damage during fault modes.
Exotic spin-Hall effect in non-Hermitian optical systems
Authors: Tan Yawei , Zhang Zan , Wang Rong , Zhou Qiang , Chen Jie , Ling Xiaohui
Published: October 2024

We systematically explore the origin and evolution of the exceptional points (EP) when a light beam is scattered by a parity-time (PT)-symmetric system using a scattering matrix approach and a full-wave theory. It is demonstrated that the PT-symmetric system switches between symmetry and symmetry-breaking phases at the EPs, giving rise to singular features in the Fresnel coefficients and causing the spin-Hall effect (SHE) near the EPs to exhibit anomalous features such as significantly enhanced transverse spin-Hall shifts and additional in-plane spin-Hall shifts. This exotic SHE can be explained by the significant beam intensity distortion caused by the destructive interference between the spin-maintained normal modes and the spin-reversed abnormal modes in the scattered light. This phenomenon can further be understood in terms of vortex mode decomposition, wherein it can be interpreted as the competition and superposition of three vortex modes with topological charges of −1, 0, and 1, respectively. These findings elucidate the mechanism of the unusual SHE around the EPs and offer potential avenues for EP-based sensing and structured light manipulation.
Emerging cost-time Pareto front for diffusion with stochastic return
Authors: Singh Prashant
Published: October 2024

Resetting, in which a system is regularly returned to a given state after a fixed or random duration, has become a useful strategy to optimize the search performance of a system. While earlier theoretical frameworks focused on instantaneous resetting, wherein the system is directly teleported to a given state, there is a growing interest in physical resetting mechanisms that involve a finite return time. However employing such a mechanism involves cost and the effect of this cost on the search time remains largely unexplored. Yet answering this is important in order to design cost-efficient resetting strategies. Motivated from this, we present a thermodynamic analysis of a diffusing particle whose position is intermittently reset to a specific site by employing a stochastic return protocol with external confining trap. We show for a family of potentials

U
R

(
x
)
∼

|

x

|

m

with m > 0, it is possible to find optimal potential shape that minimises the expected first-passage time for a given value of the thermodynamic cost, i.e. mean work. By varying this value, we then obtain the Pareto optimal front, and demonstrate a trade-off relation between the first-passage time and the work done.
Selective Rashba spin–orbit coupling manipulation in triple quantum wells
Authors: Meng Fanhua , Min Wenjing , Liu Wen
Published: October 2024

We explore the Rashba (α) spin–orbit coupling (SOC) manipulation in AlInSb/InSb triple quantum wells (QWs) with three subbands occupied in the presence of the external gate voltage V

b
. Diverse behaviors of α can be demonstrated by adjusting the structural parameters of the wells, which is greatly desirable for the design of multifunctional QW-based spintronic devices. Specifically, the first (lowest) subband always has larger Rashba coupling against the variations in the structural parameters and V

b
than the other subbands, conducive to spin detection. α

ν
s (ν = 1, 2, 3 is the subband index) of the second and third subbands take on dual (magnitude and sign) change owing to the regulation of the inner barrier height δ, may facilitating the realization of stretchable persistent spin helix in multiple QWs. Strikingly, α
3 can keep essentially zero in a wide gate range corresponding to asymmetrical QW structural configurations, by adjusting δ. However, when widening the well to a certain extent the δ-dependence of α become fixed, i.e. ∣α
1∣ > ∣α
2∣ > ∣α
3∣ maintains in wide triple-well systems. All these findings may shed light on selective and precise SOC control in QW systems for experiments.
Tribological and corrosion performance of duplex electrodeposited Ni-P/Ni-W-P coatings
Authors: Biswas Palash , Das Suman Kalyan , Sahoo Prasanta
Published: October 2024

The present research investigates the properties of duplex electrodeposited Ni-P/Ni-W-P coatings consisting of Ni-P and Ni-W-P as inner layers alternately. This study aims to examine how various heat treatment conditions affect the mechanical, tribological, and electrochemical properties of the coatings.The results show that the heat treatment temperature and duration have a profound influence on the coating’s microstructure, which significantly affects its overall performance. Optimal microhardness and lower wear rates are observed at 400 °C temperature for 1 h duration. However, at 800 °C for 4 h, duplex electrodeposited coatings display cracks and increased oxide layers, negatively impacting mechanical, tribological, and corrosion properties. The Ni-W-P outer layer coating exhibited higher hardness and a lower wear rate compared to the Ni-P outer layer coatings. However, the assessment of corrosion behavior shows that Ni-P offers increased corrosion resistance, largely due to its ability to form a passive layer, which is further enhanced after heat treatment. When compared to their individual single-layer coatings, the present duplex coatings demonstrate superior overall performance.
Synergy of photoluminescence emission and antibacterial activity of Ag-Cu2O nanocomposite
Authors: Santra Saikat , Tudu Parimal , Kuiri Bibhatsu , Pramanik Subhamay , Patra Ardhendu Sekhar , Kuiri Probodh K , Gorai Sourav , Raha Subrata
Published: October 2024

Conglomerate nanocomposites comprising metal and metal oxide hold significant potential for exhibiting properties that surpass the combined characteristics of their individual components, owing to the interactions occurring at the interfaces between the metal and metal oxide elements. In this study, we present the synthesis of Cu2O nanoparticles (NPs) (with diameters ranging from 40 to 53 nm) and Ag-Cu2O nanocomposites using an aqueous solution method at room temperature, employing varying concentrations of Ag NPs. Through optical absorption studies, we determined the optical band gap of Cu2O NPs in 0.5Ag-Cu2O, 1Ag-Cu2O, and 1.5Ag-Cu2O nanocomposites samples to be 2.13 eV, 2.25 eV, 2.34 eV, and 2.41 eV, respectively. The x-ray diffraction data are analysed using the Williamson–Hall technique and revealed noteworthy variations in microstructural characteristics such as strain and stress within the Cu2O nanocrystallites fabricated under different Ag concentrations. The nanocomposites amplified the intensities of violet-blue, blue, and green photoluminescence (PL) emissions, attributable to the interfaces between Ag and Cu2O, lattice mismatches, and the induced microstructural parameters lattice strain, and stress of Cu2O nanocrystallites. The enhanced PL intensities can be attributed to the influence of the local electric field on the Ag core composites. The Ag-Cu2O nanostructure exhibits potential applications in water purification technologies, while the PL emission properties and low band gap (∼2.13 eV) hold promising applications in optoelectronic devices. The antibacterial activities of Cu2O and Ag-Cu2O nanomaterials against Enterococcus faecalis and Escherichia fergusonii are examined using MH agar well plate diffusion methods. Here, Ag NPs enhance bactericidal effectiveness through enhanced interaction with bacteria and the release of Ag+ ions, while the Cu2O shell discontinuity on Ag NPs contributes to their unique antibacterial properties.
A study of optical properties and electron energy loss spectra of ZnS by linear response theory
Authors: Joshi Nikhil , Jangir Shruti , Sharma Saloni , Maurya Vijay , Joshi K B
Published: October 2024

The linear response theory has been applied to study the optical properties and electron energy loss spectra of ZnS. The ground state is built using the Full-Potential Linearized Augmented Plane Wave method. Thereafter, the electronic properties such as band structure and density of states are calculated. Calculations of electron energy loss spectra and optical properties are performed on the top of these ground state electronic properties. The calculations are performed using three exchange–correlation kernels namely, adiabatic local density approximation, long range contribution, and the bootstrap. The random phase approximation is also considered. An approach proposed by us to find the material dependent parameter

α

is used in long range contribution kernel to capture more accurate optical properties. Three values of

α

viz 0.78, 1.09, and 1.22 are considered. It is observed that the

α

= 0.78 gives very good results. This proposed scheme is found to work very well for ZnS also. The effect of local field and electron–hole interaction on the spectra is examined. For example after incorporating local field effect the high frequency dielectric constant

ε

∞

[i.e.

ε

1

E
→
0
e
V

], reduces by 9.19, 12.26, 13.51 and 11.02% for random phase approximation, adiabatic local density approximation, long range contribution and bootstrap kernel respectively. In EELS plasmon peak positions are found using the three kernels and random phase approximation. A good accord with experimental results is noted after incorporating local field effects. It is observed that local field effect causes redshift of prominent peak (i.e. plasmon peak) in electron energy loss spectra by 0.61 eV.
Complexity and response of bio-inspired energy harvesters based on wing-beat pattern
Authors: Huang Dongmei , Wang Kangning , Li Ruihong , Li Wei
Published: October 2024

This paper aims to investigate the dynamical mechanism of bio-inspired energy harvesters based on wing-beat pattern under harmonic excitation. Due to the existence of the gravity force in the established model, the harmonic balance method is utilized to calculate the theoretical results, which has the advantage to keep the influence of gravity force. Multiple solutions are found in the high frequency region, and they are very close in the amplitude of displacement and voltage due to the special structure of the bio-inspired energy harvester. Direct time-domain analysis verifies the effectiveness of theoretical results. The influence mechanism of the equivalent stiffness is also explored, which leads to the appearance of different states. Then, the root mean square (RMS) voltage and average power are analyzed. It is observed that a smaller damping coefficient and equivalent capacitance enhance the average electrical output and achieve greater output power. Subsequently, the bifurcation and complexity properties of the harvester are discussed. Complex phenomena are observed under different external excitations and equivalent damping, including double periodic bifurcation, multiple periodic bifurcation, and chaos phenomena. The complexity analyses confirm the effectiveness of the bifurcation results. The distribution of complexity also exhibits significant fluctuations, closely correlated with the trend of the bifurcation diagram.
Ab initio calculation of the interaction between neutral and charged silicon nanoclusters
Authors: Resseguier Antoine , Vidal François
Published: October 2024

In dusty plasmas, the formation of nanoclusters marks the beginning of the coagulation stage, leading to the rapid generation of larger particles. In this work, we present an overview of the interaction between silicon nanoclusters (SNCs) of about 1 nm diameter within the framework of density functional theory (DFT), taking into account chemical, van der Waals, and multipolar electrostatic interactions. Two types of SNCs are considered: particles composed entirely of silicon (Si30, Si40, Si50, Si60) and a particle whose dangling bonds are occupied by hydrogen atoms (Si29H24). The interaction energies obtained between two neutral or weakly charged SNCs all have a repulsive part at a short separation distance, followed by a minimum corresponding to a stable state of coagulation due to chemical bonds between the particles. In particular, our calculations show that: (1) the Hamaker constant (which characterizes the London-type van der Waals interaction) depends on the pair of identical SNCs, (2) the multipolar electrostatic contribution at large separation distances allows the extraction of the charged SNC polarization coefficient, and (3) the coagulation rates between SNCs are significantly higher than previously estimated.
Numerical optimization of inorganic p-Sb2Se3/n-ZrS2 heterojunction solar cells: achieving high efficiency through SCAPS-1D simulation
Authors: Ashfaq Arslan , Alghamdi Shoug M , Shokralla Elsammani Ali , Saad H-E M Musa , Rehman Ubaid Ur , Albalawi Hind , Bayhan Zahra , A Alsalhi Sarah
Published: October 2024

p-Sb2Se3 and n-ZrS2 materials show strong potential for cost-effective photovoltaic applications. This study presents a detailed numerical analysis of p-Sb2Se3/n-ZrS2 heterojunction solar cells using SCAPS-1D, focusing on how key parameters such as layer thickness, doping density, and bandgap have affected device performance. Critical photovoltaic metrics, such as built-in voltage (Vbi), carrier lifetime, depletion width (Wd), recombination rates, and photogenerated current, were examined. Our findings demonstrate that optimizing the p-Sb2Se3 absorber layer with a 1.0 eV bandgap, 5000 nm thickness, and doping density of 1020 cm−3 leads to a maximum efficiency of 32.14%, with a fill factor (FF) of 84.57%, short-circuit current density (Jsc) of 47.61 mA cm−2, and open-circuit voltage (Voc) of 0.792 V. For the ZrS2 buffer layer, the best performance was achieved with a 1.2 eV bandgap, 200 nm thickness, and doping density below 1 × 1020 cm−3. These optimized parameters significantly enhanced carrier separation and minimized recombination losses, leading to improved power conversion efficiency. In addition to theoretical optimization, this study emphasizes the practical potential of these materials for real-world applications. The combination of Sb2Se3 and ZrS2 offers a low-cost fabrication process suitable for scalable commercial solar cell production while maintaining high efficiency. These results underscore the viability of p-Sb2Se3/n-ZrS2 heterojunctions as promising candidates for next-generation clean energy solutions.
Influence of the annealing temperature on the self-powered CuO/ZnO NRs heterojunction photodetector
Authors: Hasach Ghaith A , Al-Salman Husam S
Published: October 2024

In this study, the fabrication and comprehensive analysis of CuO/ZnO nanorod (NR) heterojunction photodetectors were carried out, focusing on the influence of annealing temperatures (400 °C, 500 °C, and 600 °C) on their structural, optical, and electrical characteristics. The ZnO nanorods were synthesized via a hydrothermal method, followed by a spin-coating deposition of CuO thin films. The resultant heterojunctions were subjected to different annealing treatments to determine the optimal conditions for enhanced photodetector performance. Characterization techniques such as Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive x-ray Spectroscopy (EDX), x-ray Diffraction (XRD), and UV–vis spectroscopy were employed to assess the quality and composition of the heterostructures. The analyses revealed a polycrystalline structure with monoclinic phases for CuO and wurtzite phases for ZnO. Photodetectors annealed at 400 °C exhibited the highest performance metrics, achieving a photoresponse ratio (Iph/Idark) of 26.3, photosensitivity (Sph%) of 2531.6, and a specific detectivity (D*) of 4.58 × 1010 Jones under 405 nm UV light illumination. These devices also demonstrated rapid response times of 0.8 s without any external bias, indicating effective exciton separation and charge transport facilitated by the built-in electric field at the heterojunction interface. The study underscores the critical role of annealing temperature in optimizing the photodetector properties of CuO/ZnO NRs, positioning these self-powered devices as promising candidates for future ultraviolet sensor applications in optoelectronics.
Energy levels and thermodynamic models of the general molecular oscillator under a 2D electromagnetic potential field
Authors: Ahmed A D , Eyube E S , Omaghali N E J , Inuwa A , Makama M K
Published: October 2024

This study employs the parametric Nikiforov-Uvarov approach (PNUA) to resolve the radial Schrödinger equation (RSE) for the general molecular oscillator with a 2D electromagnetic potential coupling. Analytical approximations are developed for the energy levels, molar enthalpy, and constant-pressure molar heat capacity, with a focus on their applicability to diatomic molecules. The generated equations are employed to investigate the physical properties of real substances like BeCl (X 2Σ+), CsF (X 1Σ+), CuCl (X 1Σ+), CO+ (X 2Σ+), 7Li2 (1 3Δg), and P2 (X 1Σg
+) molecules. The percentage average absolute deviations (PAAD) deduced with the analytical model equations are found to agree with the findings on diatomic molecules. Analysis of PAAD values also reveals that the predicted molar enthalpy and heat capacity of the diatomic molecules are better if the magnetic and Aharonov-Bohm components of the EM potential fields are finite.
State-dependent and state-independent uncertainty relations for skew information and standard deviation
Authors: Sahil
Published: October 2024

In this work, we derive state-dependent uncertainty relations (uncertainty equalities) in which commutators of incompatible operators (not necessarily Hermitian) are explicitly present and state-independent uncertainty relations based on the Wigner-Yanase (-Dyson) skew information. We derive uncertainty equality based on standard deviation for incompatible operators with mixed states, a generalization of previous works in which only pure states were considered. We show that for pure states, the Wigner-Yanase skew information based state-independent uncertainty relations become standard deviation based state-independent uncertainty relations which turn out to be tighter uncertainty relations for some cases than the ones given in previous works, and we generalize the previous works for arbitrary operators. As the Wigner-Yanase skew information of a quantum channel can be considered as a measure of quantum coherence of a density operator with respect to that channel, we show that there exists a state-independent uncertainty relation for the coherence measures of the density operator with respect to a collection of different channels. We show that state-dependent and state-independent uncertainty relations based on a more general version of skew information called generalized skew information which includes the Wigner-Yanase (-Dyson) skew information and the Fisher information as special cases hold. In qubits, we derive tighter state-independent uncertainty inequalities for different form of generalized skew informations and standard deviations, and state-independent uncertainty equalities involving generalized skew informations and standard deviations of spin operators along three orthogonal directions. Finally, we provide a scheme to determine the Wigner-Yanase (-Dyson) skew information of an unknown observable which can be performed in experiment using the notion of weak values.
Channel modelling in underwater media: a wireless communication technique perspective
Authors: Kumar Gupta Sushil , Chandra Singh Chauhan Ram , Kumar Vinay
Published: October 2024

With a broad scope of exploration and utilization of marine resources, the field of underwater wireless communication (UWC) is attracting the growing interest of researchers. Due to the highly complex and changing underwater environment, achieving minimal Doppler Effect, extensive communication range, maintaining link reliability, and high channel efficiency is challenging. Underwater information transfer can utilize various communication techniques, including Acoustic, Optical, Radio Frequency (RF), and Magnetic Induction (MI)-based communication. Accurate channel modelling is essential for optimizing UWC’s overall performance. Each underwater communication technique has its strengths and weaknesses. This review article discusses the detailed channel modelling of Acoustic, Optical, MI, and RF communications, comparing them across parameters such as path loss, channel capacity, channel error control protocols, bit error rate (BER), the impact of reconfigurable intelligent surface (RIS), and outage probability are briefly discussed. Additionally, critical unresolved issues related to the channel modelling of UWC techniques are highlighted. This review article will assist researchers in identifying research gaps and conducting further research in the field.
A connection between massive electrodynamics and the Einstein-Maxwell equations
Authors: Alqrayan Waad A , Arbab Arbab I
Published: October 2024

Quaternions are the best mathematical construct for creatingvarious equations in electrodynamics, which has led to the emergence of new terms with unique physical implications. Since quaternions also have noncommutative properties that are reflected in curved space-time too, a formulation of a theory using quaternions can be compared with that formulated in some curved space-time. Furthermore, we calculate the Maxwell equations in curved space-time and observe the presence of extra terms that are not present in flat space-time. An electric current arises because of the coupling between the magnetic field and curvature. Upon comparing the outcomes of the two methods, we discovered a correlation between mass and gravity, indicating their similarity. Equations formulated via quaternions are equivalent to those formulated in curved space-time. The optical chirality and its flux are generalized to massive electrodynamics.
Chlorella-enriched hydrogels protect against myocardial damage and reactive oxygen species production in an in vitro ischemia/reperfusion model using cardiac spheroids
Authors: Tarsitano Martine , Liu Chung Ming Clara , Bennar Lucia , Mahmodi Hadi , Wyllie Kaitlin , Idais Dana , Al Shamery Wafa , Paolino Donatella , Cox Thomas R , Kabakova Irina , Ralph Peter , Gentile Carmine
Published: October 2024

Microalgae have emerged as promising photosynthetic microorganisms for biofabricating advanced tissue constructs, with improved oxygenation and reduced reactive oxygen species (ROS) production. However, their use in the engineering of human tissues has been limited due to their intrinsic growth requirements, which are not compatible with human cells. In this study, we first formulated alginate–gelatin (AlgGel) hydrogels with increasing densities of Chlorella vulgaris. Then, we characterised their mechanical properties and pore size. Finally, we evaluated their effects on cardiac spheroid (CS) pathophysiological response under control and ischemia/reperfusion (I/R) conditions. Our results showed that the addition of Chlorella did not affect AlgGel mechanical properties, while the mean pore size significantly decreased by 35% in the presence of the 107 cells ml−1 microalgae density. Under normoxic conditions, the addition of 107
Chlorella cells ml−1 significantly reduced CS viability starting from 14 d in. No changes in pore size nor CS viability were measured for hydrogels containing 105 and 106
Chlorella cells ml−1. In our I/R model, all Chlorella-enriched hydrogels reduced cardiac cell sensitivity to hypoxic conditions with a corresponding reduction in ROS production, as well as protected against I/R-induced reduction in cell viability. Altogether, our results support a promising use of Chlorella-enriched Alg–Gel hydrogels for cardiovascular tissue engineering.