bluuebunny/crossref_metadata_2025_split huggingface dataset:
An identical bipolar buck‐boost AC‐AC converter based on a coupled‐inductor with safe‐commutation, high gain, and high efficiency
Authors: Ahmed Hafiz Furqan , Lahooti Eshkevari Alireza , Abdoli Iman 
Published: November 2024

AbstractThis article proposes a new identical bipolar buck‐boost AC‐AC converter with integrated coupled inductors. It possesses all the critical features of a bipolar buck‐boost topology, providing both in‐phase and anti‐phase output voltages. Compared to its counterparts, a high boost factor is achieved without large duty ratios due to using magnetic coupling. Also, a high efficiency is obtained. A unipolar half‐cycle modulation is employed in which only half of the switches of a phase‐leg are modulated per half‐cycle. Therefore, only two out of eight power switches operate at high frequency at any instant, ensuring high‐efficiency operation. The safe‐commutation operation is achieved by completely turning on the auxiliary switches of the main phase leg for a half‐cycle, ensuring a continuous inductor current path during dead times. This results in voltage‐spike‐free operation. Additionally, this converter benefits from continuous input current and performs well with inductive and non‐linear loads. The proposed topology can mitigate both voltage sags and swells due to bipolar operation when employed as a dynamic voltage restorer (DVR). Its high boost factor helps compensate for deep voltage sags (above 50%). This article presents the detailed theoretical aspects of the proposed topology, followed by experimental verifications on laboratory‐built hardware.
Integration of a solid oxide electrolysis system with solar thermal and electrical energy: A testing campaign for operation and control strategy definition
Authors: Crespi Elena , Panaccione Francesca , Ragaglia Davide , Testi Matteo 
Published: November 2024

AbstractThe EU project PROMETEO has the scope of testing a 25 kW solid oxide electrolysis system integrated with a concentrated solar power plant via thermal energy storage in a relevant environment. Given the plant layout and the hydrogen demand characteristics, this work aims to identify how to operate the system effectively when renewable electricity is unavailable and how to modulate the load during hydrogen generation, thus defining the system's operation modes and control strategy. A 5 kWe stack has been tested at the FBK facility. The hot standby tests show that feeding a reducing gas at the negative electrode and air at the positive electrode, without polarizing the stack, effectively keeps the stack hot at 750°C and prevents degradation. Conversely, the electric protection approach leads to significant stack degradation (15% voltage drop in 200 h for one cluster). Regarding modulation of hydrogen generation, with low steam flowrates, the stack current and the flow rate of produced hydrogen mainly depend on the steam flow rate, while it is not affected by the stack temperature; conversely, with high steam flowrates, the current depends only on the stack temperature (from 25 A at 670°C to 65 A at 760°C). Based on the results, two hot standby modes and two load control strategies to be implemented and tested in the PROMETEO prototype are proposed.
Overcoming Boundaries: Interventional Oncology Paving the Way for Cholangiocarcinoma Resection
Authors: Koethe Yilun , Gurusamy Varshana 
Published: November 2024

AbstractIntrahepatic cholangiocarcinoma (ICC) has been increasing in the United States and other Western countries and carries a very poor prognosis. Currently, the only curative option is surgical resection, which can increase the 5-year survival from 5 to 30%. However, only 15% of cases of ICC are resectable at the time of diagnosis. With the development of new interventional treatment strategies, including radioembolization, chemoembolization, and portal and hepatic venous embolization, interventional radiologists are playing an increasing role in downstaging and improving the survival outcomes of patients who were initially unresectable.
Efficient wide-angle broadband blazed gratings enabled by metasurfaces
Authors: Li Chunshu , Guo Yongjun , Wang Yang , Guo Yuhao , Zhang Lin 
Published: November 2024

Metasurfaces composed of two-dimensional nanopillar arrays can manipulate light fields in desirable ways and exhibit the unique advantage of beam steering. Here, we experimentally demonstrate a metasurface-based wide-angle broadband all-dielectric blazed grating with an extreme incident angle of up to 80°, which is achieved by optimizing the wide-angle phase shifts and transmissivities of the unit cells. It exhibits a maximum diffraction efficiency of 72% and a high average efficiency of 64% over a wide range of incident angles from −80° to 45° at 1.55 μm. Moreover, the proposed grating has a broad bandwidth of 200 nm (1.45–1.65 μm), and average efficiencies of more than 50% can be achieved experimentally over the same incidence angles. Our results may pave the way for the creation of novel and efficient flat optical devices for wavefront control.
Numerical investigation of bandgap characteristics in integrated metallic metafilters for nonlinear guided wave applications
Authors: Aslam Mohammed , I Boris , Lee Jaesun 
Published: November 2024

Guided waves propagating in nonlinear media, featuring second harmonic generation, represent a promising avenue for early-stage damage detection due to their high sensitivity and long-range propagation capabilities. However, nonlinear ultrasonic measurements are hindered by nonlinearities induced by the experimental system, necessitating careful calibrations that have restricted their application to laboratory settings. While several phononic crystal and metamaterial designs have been devised to enhance nonlinear-based ultrasonic testing, most are tailored for suppressing second harmonics within a frequency range of 100–300 kHz, primarily utilizing low-frequency excitation. In this paper, we propose a metallic ring-shaped metafilter designed to explore high-order bandgaps. To fully understand the bandgap characteristics, we begin by analyzing mode shapes, providing insights into the underlying wave mechanics. The efficacy of the designed filter is subsequently assessed through 3D time step elastodynamic simulations. In addition, this study underscores the significance of parameters such as the number of rings employed in the filter, signal duration, and bandgap width in optimizing its performance. Furthermore, the observed mode conversion phenomena from S0 to A0 guided wave modes underscore the filter’s capacity to influence guided wave propagation. The defect localization technique, based on the time difference of arrival of second-order wave modes, accurately predicts the defect location with an error margin of less than 0.2%. The present investigation showcases advancements in the sensitivity of nonlinear-based guided wave testing for characterizing microstructural changes, promising substantial potential for detecting incipient damage in practical structural health monitoring applications.
Nanoscale Ga/Al substituted yttrium iron garnet films by liquid phase epitaxy
Authors: Zhang Yuanjing , Xue Qiang , Wang Feng , Li Han , Li Zhuo , Yang Shuting , Liu Yingli , Hu Aimin , Jin Lichuan , Wen Qiye , Zhang Huaiwu , Yang Qinghui 
Published: November 2024

Yttrium iron garnet (YIG) has minimum damping factor and low ferromagnetic resonance (FMR) linewidth, making it a preferred material for low loss microwave and spintronic devices. The saturation magnetization of YIG is 1750 Gauss, and for low-frequency devices, a lower saturation magnetization is more suitable. Ga3+ and Al3+ are with smaller radii and non-magnetic moment, so the substitution of Ga3+ and Al3+ can decrease saturation magnetization. Here, 4.8–193.7 nm ultra-thin Y3(GaAlFe)5O12 garnet (GaAl-YIG) monocrystalline films are prepared on gadolinium gallium garnet (GGG) substrates by using the liquid-phase epitaxy (LPE) method. As expected, these films exhibit a low saturation magnetization of almost less than 100 Gauss, while their FMR linewidth remains at levels close to that of YIG. The films show a (111) orientation and in a state of tension, and the diffraction intensity of the films get stronger as films thickness increases. The free energy and density of states are calculated for different Ga/Al substitution position by density functional theory simulations. The elements show a different diffusion distance in the GaAl-YIG/GGG interface, and the variation of magnetization properties with interface width are analyzed. The surface roughness of the films is only a few angstroms. The damping factor of these ultra-thin films are on an order of 10−4 except the 4.8 nm film, which suggests that the minimum thickness of the garnet film with good performance by using the LPE method is about 10 nm. According to the analysis of structure and magnetization properties, it demonstrates that the LPE method has potential to provide nanoscale garnet films for low loss microwave and spintronic devices.
Generating stacking faults in 4H–SiC junction transistor by indentation and forward biasing
Authors: Zhang Tingwei , Kitai Adrian 
Published: November 2024

Stacking faults in silicon carbide have been widely studied due to their negative impact on the application of silicon carbide in the power electronics industry. In this work, with the assistance of forward biasing, we observe several triangular shaped structures emerging near the indenter imprint in two separate 4H–SiC bipolar junction transistor samples that were deformed by nanoindentation. Based on the study of electroluminescence spectra on one of the samples, the emission peak at 420 nm indicates the formation of single Shockley stacking faults inside deformed transistors. We conclude that the use of indentation can provide a method to study recombination induced stacking faults in silicon carbide junction devices by intentionally introducing dislocations at selected areas of interest.
Bio-inspired chitosan/polyvinyl alcohol/tannic acid hydrogels as plant grafting wood adhesives
Authors: Bae Haejin , Shin Hyun Ho , Ryu Ji Hyun 
Published: November 2024

Recently, there has been growing interest in plant-inspired materials for various biological, medical, and industrial applications. Notably, tannic acid-based materials exhibit remarkable adhesive properties and can be used in a variety of applications, particularly biomedical applications. In addition, mixtures composed of tannic acid and polymers (e.g., polyvinyl alcohol) exhibit excellent adhesion to various substrates. In this study, we developed gallol-containing chitosan (G-CS), polyvinyl alcohol (PVA), and tannic acid (TA) composite (G-CPT) hydrogels as wood adhesive materials. G-CPT hydrogels were immediately formed by mixing the G-CS/PVA solution with the TA solution. Rheological analysis revealed an increase in the elastic modulus (G′) with the addition of small amounts of G-CS. In addition, the detachment stress of wood sticks attached using G-CPT hydrogels was 142.2 ± 7.2 MPa, which was substantially higher than that of G-CS (5.3 ± 1.4 kPa), PVA (2.2 ± 0.2 kPa), TA (0.4 ± 0.1 kPa), and PVA/TA hydrogels (106.5 ± 2.5 MPa). Furthermore, G-CPT hydrogels can be used as wood adhesives for scion grafting into the rootstock of English ivy. These findings highlight the importance of G-CPT hydrogels as eco-friendly wood adhesives with enormous potential for various industrial and agricultural applications.
New distribution records of the coconut crab (Birgus latro) in eastern Polynesia on Oeno Atoll, Henderson Island, and Ducie Atoll, Pitcairn Islands
Authors: Bond Alexander L. , Lavers Jennifer L. 
Published: November 2024

Coconut (or robber) crabs (Birgus latro) are found throughout the Indo-Pacific, including as far east as the Gambier Islands, French Polynesia, though the eastern edge of their range is poorly defined. Here, we document narratives and occurrences of coconut crabs on Oeno Atoll, Henderson Island, and Ducie Atoll in the Pitcairn Islands, which extends the currently known eastern limit of coconut crabs’ range by >600 km. Crabs are not abundant on the islands, but suitable habitat and prey are available, so larger populations may be present, particularly on Henderson Island. Edge-of-range populations are often the most susceptible to pressures, but the remoteness of the Pitcairn Islands may shield coconut crabs from threats present elsewhere in the Indo-Pacific region.
Modeling and simulation of optical gain of GaP0.3Sb0.7/InP0.7Sb0.3 type-II heterostructure for IR optoelectronics under variable well width, temperature and external electric field
Authors: Rathi Amit , Chaudhary Priya 
Published: November 2024

Abstract
The type-II GaP0.3Sb0.7/InP0.7Sb0.3 nanoscale heterostructure is modelled and simulated for its optical properties in near-infrared lasing applications. The optical gain of GaP0.3Sb0.7/InP0.7Sb0.3 type-II heterostructure is analyzed under different external values of electric fields, temperatures and well widths at room temperature 300 K. The complete structure is grown on InP substrate. The effects of a varied temperature (290 K–320 K), quantum well width (2 nm, 3 nm, and 4 nm) and applied electric field (20 kV cm−1–8 0 kV cm−1) are explored regarding the band alignment, wavefunction, band dispersion, matrix elements, gain and wavelength. The Luttinger-Kohn model is utilized to compute the band structure. The gain computation involves the evaluation of the 6 × 6 k·p Hamiltonian matrix. The proposed heterostructure at 2 nm quantum well width exhibits a high optical gain of 14998 cm−1 in x-polarization and 16572 cm−1 in y-polarization for injected carrier concentration of 4 × 1012 cm2. Under variable temperature and electric field, a significant optical gain is achieved in x, y and z input polarizations. This heterostructure is regarded as new because of its very high optical gain in NIR regime, that makes it beneficial for optoelectronics.
Performance evaluation and optimization of flux-regulated axial-radial eddy current coupling
Authors: Li Zhao , She Yihao , Chai Xuzhao , Bian Fangfang 
Published: November 2024

Abstract
This paper proposes a novel axial-radial permanent magnet eddy-current coupling equipped with a mechanical magnetic adjuster. The innovative design integrates mechanical flux weakening technology with an enhanced magnetic method rooted in axial-radial hybrid flux topology. Concise analytical models for air-gap field and torque are developed, leveraging the magnetic equivalent circuit method and Faraday’s law. These models are subsequently validated using the 3D finite-element method. The results indicate that this device boasts an exceptionally broad torque adjustment range, reaching approximately 93% at a given slip. Furthermore, it exhibits a substantial optimal working area, spanning from 20% to 80% of the mechanical magnetic adjuster’s movable distance. To comprehensively analyze the impact of structural parameters on overall performance, three novel metrics are defined. The analysis reveals that the pole pairs of the radial magnetic circuit (RMC) have the most significant influence on the device’s comprehensive performance. In the end, a multi-objective optimization method to maximize the global torque regulation capabilities, local torque regulation abilities, and maximum torque potential is developed to enhance the overall performance of this innovative magnetic coupling design.
Exploring HgO effect on structural, dielectric, optical, and radiation shielding properties of borate-based glass
Authors: Tharwat Mohamed , El-Mesady Intesar A , Abd-Allah Wesam M , Ibrahim Samia E 
Published: November 2024

Abstract
Glass samples in the system

60
−
x

B

2

O

3

+
20
BaO
+
20

K

2

O
+
xHgO

(0 ≤ x ≤ 15 mol%) were prepared via melt quenching method. Infrared spectroscopy revealed structural modifications with increasing HgO content, characterized by a shift in the BO4/BO3 ratio. Dielectric and impedance spectroscopy studies indicated enhanced ionic conductivity with higher HgO concentrations. Optical properties, including refractive index, extinction coefficient, and optical band gap, were determined. The optical absorption edge exhibited a red shift with increasing HgO, attributed to structural changes. Refractive index measurements showed an anomalous dispersion behavior at shorter wavelengths, followed by normal dispersion at longer wavelengths. Optical band gap calculations indicated a decrease with increasing HgO content, suggesting increased disorder. The mass attenuation coefficient (MAC) and linear attenuation coefficient (LAC) were calculated using the Phy-X/PSD software. Increasing HgO content led to a significant enhancement in both MAC and LAC values, particularly at lower energies. The mean free path (MFP) exhibited a corresponding decrease with higher HgO content. Overall, the results demonstrate the potential of these glasses as effective radiation shielding materials.
MHD casson fluid flow over a stretching surface with suction, double stratification, and heat and mass transfer effects
Authors: Kumar Himangshu , Nath Rupam Shankar , Deka Rudra Kanta 
Published: November 2024

Abstract
This article examines how a magnetohydrodynamic Casson fluid moves across a stretching surface in a double-stratified medium. Thermal radiation, suction, heat sources, viscous dissipation, and chemical reactions drive the stream field. We converted the flow describing partial differential equations into terms of ordinary differential equations by applying appropriate transformations. Next, we used the bvp4c package in Matlab to obtain numerical solutions for these equations. We explored and graphically showed the implications of different non-dimensional governing parameters for temperature, concentration, and velocity profiles. After analysis, we provide a tabular presentation of the friction factor, Nusselt, and Sherwood numbers. The Casson fluid temperature shows a rising trend for the solutal stratification parameter and a decreasing trend for the thermal stratification parameter, while the Casson fluid velocity shows a declining trend for both of these parameters. The Casson fluid concentration also behaves differently depending on the stratification parameter; for example, it increases for thermal stratification and decreases for solutal stratification. We notice an increase in the Casson parameter's value suppresses the velocity field. However, as the Casson parameter increases, both the temperature and the concentration improve. Furthermore, comparisons with previously published findings also support the current results. Many different fields find it useful to study MHD Casson fluid flow, which includes suction, dual stratification, and the effects of heat and mass transfer. These fields include polymer processing, metallurgical engineering, biomedical applications, environmental sciences, and advanced cooling technologies.
Incorporation of graphene quantum dots into magnesium copper phosphate (GQDs-MgCuPO4) for supercapattery and electrocatalysis applications
Authors: Al-Balawi S A , Al-Ojeery A , Hassan Haseebul , Iqbal M Waqas , Afzal Amir Muhammad , Aly K A 
Published: November 2024

Abstract
We efficiently synthesize magnesium copper phosphate nanoparticles (MgCuPO4) doped with graphene quantum dots (GQDs) using a hydrothermal method for supercapattery and oxygen evolution reactions in KOH electrolyte. The GQDs-MgCuPO4 electrode has a high specific capacity (1188 Cg−1 at 1.0 Ag−1) and a high rate capability (67%). The symmetric supercapattery (GQDs-MgCuPO4//GQDs-MgCuPO4) provides a staggering energy density of 46 Wh-kg−1, as well as a high power density of 1300 W-kg−1 and a high cyclic stability of 93% after 10,000 cycles. Furthermore, it demonstrates high efficiency in the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), with corresponding low overpotentials of 181 mV and 119 mV. The GQDs-MgCuPO4 stands out as a capable solution for various energy storage and conversion difficulties.
Gill and Massar type bound for estimation of SU(2) channel
Authors: Yamagata Koichi 
Published: November 2024

Abstract
In the estimation for a parametric family of quantum state on a Hilbert space

H

, the Gill and Massar bound is known as a lower bound of weighted traces of covariances of unbiased estimators. The Gill and Massar bound is derived by considering the convexity of the set of classical Fisher information matrices, and the bound is locally achievable by using randomized strategies when

H
=

C

2

. In this paper, we show that estimation for a parametric SU(2) unitary channel model has a similar convex structure as qubit state model, and a Gill and Massar type lower bound of weighted traces of covariances of unbiased estimators can be derived for any weight matrix. We show that the Gill and Massar type lower bound is achievable by using randomized strategies when certain conditions are satisfied. To derive a convex structure of the set of classical Fisher information matrices, we introduce a Fisher information matrix J
(U) for a SU(2) unitary channel model, and we show a upper bound of inverse J
(U) weighted trace of classical Fisher information matrix. The optimal randomized strategy we construct in this paper does not require ancilla systems in many cases.
Photonic hook shaping achieved by the micro-nano fiber array based Janus cylindrical metalens
Authors: Dinh Quoc-Thinh , Wu Yi-Cin , Chen Wei-Yu , Chen Yu-Bin , Minin Oleg V , Minin Igor V , Liu Cheng-Yang 
Published: November 2024

Abstract
Near-field focusing of an electromagnetic wave on the assembly of hexagonally asymmetric arranged close-contact nanofibers into a cylindrical Janus metalens is considered for different fiber sizes and optical properties. We propose combining the meta-material concept with a photonic hook based on the finite-difference time-domain technique. Simulation results show that the cylindrical meta-photonic Janus structure produces the focal region of enhanced optical intensity, which exists in the spatial form of a localized structured light known as a photonic hook. A detailed study of all key parameters of a photonic hook depending on the Janus metalens topology and optical properties of the fiber filling is carried out. The structure conditions have been determined for the beam waist of a photonic hook that is less than the diffraction limit. This Janus cylindrical metalens may contribute to the versatile control of photonic hook generation in the applications of bio-photonics and optical microscopes.
Micro-discharge in GIS/GIL induced by scratch defect on the surface of insulation pull rods
Authors: Li ChangYun , Zhu Feng , Zhu Yujie , Li Chuanyang 
Published: November 2024

Abstract
The insulation pull rod (IPR) plays a crucial role in gas insulated switchgear (GIS) and gas insulated transmission line (GIL), which must withstand high impulse voltages to cope with frequent switching operations under working conditions. During the manufacturing process, micro-defects may occur on the surface of insulation pull rods, which may cause micro-discharge or even breakdown. It is difficult to carry out experiments to study the microscopic characteristics of the micro-discharge induced by micro-defects on the surface of the insulation pull rod. In order to study the relationship between the micro-discharge and the micro-defects. Firstly, the characterization of the scratch defect based on Micro-CT (micro computed tomography) and white light interference are presented. Secondly, a coaxial DC SF6 corona discharge model is established to obtain the curve related to the density of charged particles in SF6 and the electric field. Finally, we combined the reconstruction of the defect model in the first step with the curve obtained in the second step to simulate the micro discharge around the scratch defect, and provided the micro-discharge in pure SF6 caused by the scratch defect. The phenomenon of micro-discharge induced by the scratch of insulation pull rod is explained. The oscillation phenomenon of internal micro-discharge in scratch defects under high electric field background is discovered.