bluuebunny/crossref_metadata_2025 huggingface dataset:
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

The 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

Intrahepatic 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.
Optimal capacity allocation and scheduling strategy for CSP+PV hybrid standalone power plants
Authors: Lin Xiangning , Chen Shu
Published: November 2024

Solar photovoltaic (PV) power generation, as an important clean technology, has been widely adopted globally, especially in remote island areas where access to the main power grid is unavailable. PV power can serve as the primary energy source for standalone island grids. However, due to its dependence on sunlight, PV power output fluctuates, particularly during nighttime and under poor lighting conditions, necessitating the integration of energy storage technology or alternative power generation methods to ensure continuous power supply. Concentrating solar power (CSP) generation, as an emerging technology, can provide efficient power output when solar radiation is abundant and ensure continuous power supply through thermal energy storage systems during adverse weather conditions or nighttime. Although CSP offers advantages such as dispatchability, its high construction and maintenance costs may pose challenges in commercial deployment. Hybrid solar power plants combining both PV and CSP technologies leverage the strengths of both, ensuring more stable and economically viable power output. This study establishes a model for hybrid solar power plants, considering the impact of PV and CSP component capacities and proportions on performance and costs, i.e., capacity allocation. To maximize the overall benefits of standalone microgrids while ensuring the stability of the power station, a capacity allocation method guided by economic dispatch is proposed. Through iterative analysis, the optimal configuration is determined to minimize the system's equivalent annual costs. Simulation experiments validate the financial feasibility of hybrid solar power plants and the reliability of the proposed configuration method.
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.
Micromotor based on single fiber optical vortex tweezer
Authors: Wu Luping , Bai Zhiyong , Wang Yuji , Liu Rui , Yu Jian , Ran Jianjun , Luo Zilun , Liu Shen , Wang Ying , Chen George Y. , He Jun , Liao Changrui , Wang Yiping
Published: November 2024

Optical micromotors are powerful tools for trapping and rotating microparticles in various fields of bio-photonics. Conventionally, optical micromotors are built using bulk optics, such as microscope objectives and SLMs. However, optical fibers provide an attractive alternative, offering a flexible photon platform for optical micromotor applications. In this paper, we present an optical micromotor designed for 3D manipulation and rotation based on a single fiber optical vortex tweezer. A tightly focused vortex beam is excited by preparing a spiral zone plate with an ultrahigh numerical aperture of up to 0.9 at the end facet of a functionalized fiber. The focused vortex beam can optically manipulate and rotate a red blood cell in 3D space far from the fiber end facet. The trapping stiffness in parallel and perpendicular orientations to the fiber axis are measured by stably trapping a standard 3-µm silica bead. The rotational performance is analyzed by rotating a trimer composed of silica beads on a glass slide, demonstrating that the rotational frequency increases with rising optical power and the rotational direction is opposite to the topological charge of the spiral zone plate. The proposed fiber micromotor with its flexible manipulation of microparticle rotation circumvents the need for the precise relative position control of multiple fiber combinations and the use of specialized fibers. The innovations hold promising potential for applications in microfluidic pumping, biopsy, micromanipulation, and other fields.
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.
Three-chamber electrochemical reactor for selective lithium extraction from brine
Authors: Feng Yuge , Park Yoon , Hao Shaoyun , Fang Zhiwei , Terlier Tanguy , Zhang Xiao , Qiu Chang , Zhang Shoukun , Chen Fengyang , Zhu Peng , Nguyen Quan , Wang Haotian , Biswal Sibani Lisa
Published: November 2024

Efficient lithium recovery from geothermal brines is crucial for the battery industry. Current electrochemical separation methods struggle with the simultaneous presence of Na
+
, K
+
, Mg
2+
, and Ca
2+
because these cations are similar to Li
+
, making it challenging to separate effectively. We address these challenges with a three-chamber reactor featuring a polymer porous solid electrolyte in the middle layer. This design improves the transference number of Li
+
(t

Li
+

) by 2.1 times compared to the two-chamber reactor and also reduces the chlorine evolution reaction, a common side reaction in electrochemical lithium extraction, to only 6.4% in Faradaic Efficiency. Employing a lithium-ion conductive glass ceramic (LICGC) membrane, the reactor achieved high t

Li
+

of 97.5% in LiOH production from simulated brine, while the concentrations of Na
+
K
+
, Mg
2+
, and Ca
2+
are below the detection limit. Electrochemical experiments and surface analysis elucidated the cation transport mechanism, highlighting the impact of Na
+
on Li
+
migration at the LICGC interface.
Functional alterations of the magnocellular subdivision of the visual sensory thalamus in autism
Authors: Schelinski Stefanie , Kauffmann Louise , Tabas Alejandro , Müller-Axt Christa , von Kriegstein Katharina
Published: November 2024

The long-standing hypothesis that autism is linked to changes in the visual magnocellular system of the human brain has never been directly examined due to technological constraints. Here, we used a recently developed 7-Tesla functional MRI (fMRI) approach to investigate this hypothesis within the visual sensory thalamus (lateral geniculate nucleus, LGN). The LGN is a crucial component of the primary visual pathway. It is particularly suited to investigate the magnocellular visual system, because within the LGN, the magnocellular (mLGN) uniquely segregates from the parvocellular (pLGN) system. Our results revealed diminished mLGN blood-oxygenation-level-dependent (BOLD) responses in the autism group compared to controls. pLGN responses were comparable across groups. The mLGN alterations were observed specifically for stimuli optimized for mLGN function, i.e., visual displays with low spatial frequency and high temporal flicker frequency. The results confirm the long-standing hypothesis of magnocellular visual system alterations in autism. They substantiate the emerging perspective that sensory processing variations are part of autism symptomatology.
Interdisciplinary insights into the cultural and chronological context of chili pepper (
Capsicum annuum
var.
annuum
L.) domestication in Mexico
Authors: Chiou Katherine L. , Lira-Noriega Andrés , Gallaga Emiliano , Hastorf Christine A. , Aguilar-Meléndez Araceli
Published: November 2024

This study investigates the temporal and spatial factors driving the domestication of
Capsicum annuum
var.
annuum
L. in Mexico. This species exhibits the greatest morphological diversity in fruit among
Capsicum
species—a characteristic that is even more pronounced in contemporary landraces cultivated by indigenous communities. Despite the chili pepper’s integral role in regional culinary traditions, its domestication history in this region remains poorly understood, often subject to scholarly interpretations that marginalize or oversimplify archaeological evidence. To address this gap, our interdisciplinary team of archaeologists, botanists, and ecologists combine modern and archaeological
Capsicum
seed data, diachronic archaeological site locations, and ecological niche modeling to identify potential regions where early human populations and the closest wild ancestors may have coexisted. Our results show spatial correlations between early
Capsicum
distribution and archaeological site prevalence, suggesting that the beginning of the domestication process occurred in ecologically suitable areas for both wild
Capsicum
and human settlement. These findings challenge previous hypotheses regarding highland/dry cave domestication regions, as our data indicate that lowland regions—specifically the Yucatán Peninsula and southern coastal Guerrero—were more conducive to early encounters between wild
Capsicum
and humans. We propose a geographically diffuse and protracted model of chili pepper domestication—driven by a ruderal pathway—which involved at least two asynchronous events across Mexico.
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

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

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

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

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

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

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

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

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.
First-principles investigation on the structure, electronic, mechanical and optical properties of silver based perovskites AgBX3 (B=Be, Mg; X=Br and I)
Authors: Zhang JingYi , Yu Jianghao , Chen Yan , Chen Shanjun , Liu Jin , Li Song , Shi Zaifa
Published: November 2024

The structure, mechanical, electronic and optical properties of Ag-based halides AgBX3 (B = Be, Mg; X = Br, I) were studied using first-principles approach for the first time. The elastic constants reveal that these materials are mechanical stability. The results of Pugh’s ratio, bulk modulus, Poisson’s ratio, and anisotropy coefficients exhibit that these compounds are ductility, anisotropy, and ionic properties, and the hardness of beryllium compounds is larger than that of magnesium compounds. The band structure and density of states for AgBX3 show that AgBeBr3, AgMgBr3, and AgMgI3 compounds are indirect bandgap semiconductors, while AgBeI3 has metallic property. The valence band of the AgBX3 is mainly dominated by Ag-d and X-p orbital electrons, and the conduction band is composed predominantly of B-p and X-s orbital electrons. The optical properties of AgBX3 were analyzed in the energy range 0–30 eV. It is found that AgBX3 has high transparency in visible light range and good ultraviolet light absorption ability, which reflects that AgBX3 can be employed as window and lens materials in visible light range and ultraviolet optical devices.
Optical, thermal, and radiation shielding characterization of bismuth-modified zinc-lithium-tungsten-borate glass
Authors: Usman Iliyasu , Mohd Sanusi Mohamad Syazwan , Ahmad Nor Ezzaty , Thabit Hammam Abdurabu
Published: November 2024

This study examines the optical, thermal, and radiation attenuation properties of zinc-tungsten-lithium-borate glass modified with Bi2O3, synthesized using melt-quench techniques. The resulting glass samples display a significant physical property, with density increasing from 3.22 g cm−3 to 4.84 g cm−3 as Bi2O3 concentration increase from 2 to 16 mol%. The optical band gap narrows from 2.9 eV to 2.55 eV, while the refractive index increases from 2.42 to 3.49, indicating a shift in absorption to lower energy levels. Higher Bi2O3 concentrations reduce optical non-linearity while enhancing the linear optical properties of the synthesized glasses. The formation of orthoborate anions suggests that Bi3+ ions in the glasses act as network modifiers, disrupting the borate framework and introducing structural disorder. Additionally, thermal properties, including glass transition temperature (

T

g

), crystallization temperature (

T

c

), and melting temperature (

T

m

), decrease with increasing Bi2O3 concentration. The radiation shielding effectiveness is significantly improved, with the linear attenuation coefficient (LAC) increasing from 0.56 cm−1 to 1.35 cm−1 at 0.284 MeV and from 0.127 cm−1 to 0.186 cm−1 at 2.506 MeV as Bi2O3 content rises from 2 mol% to 16 mol%. For a glass thickness of 1 cm, the radiation protection efficiency reaches approximately 74% for a photon energy of 0.284 MeV in the sample doped with 16 mol% Bi2O3. The glass’s remarkable combination of high transparency and effective radiation attenuation, positions it as a promising option for radiation shielding applications.
Interface dynamics in electroosmotic flow systems with non-Newtonian fluid frontiers
Authors: Chen Di-Lin , Liu Shu-Yan , Luo Kang , Yi Hong-Liang , Yang Chun
Published: November 2024

Microfluidic applications involving liquid manipulation, selective membranes, and energy harvesting strongly emphasize the importance of the electrokinetic phenomenon, which is widely used at multiple fluid and electrochemical interfaces. However, critical scientific issues that address multifield coupling and multiscale physics have not been well addressed in non-Newtonian fluids. In this paper, electrical field–fluid flow–ion transport coupling is numerically implemented in two mainstream problems, i.e., induced electroconvection phenomena at ion-selective interfaces and induced charge electroosmosis in polarized cylinders. The effects of different non-Newtonian rheological properties, which are absent in Newtonian fluids, on the interfacial dynamics, instability and ion transport are examined. The results reveal that the non-Newtonian rheology significantly modulates the statistical data and interfacial phenomena. Generalized power-law fluids alter velocity and interfacial charge profiles, with shear thinning enhancing ion transport to lower overlimiting current thresholds and shear thickening broadening the limiting current region (with hindered ion transport). In Boger-type Oldroyd-B fluids, the addition of polymer decreases the velocity amplitude and increases the interface resistance. At low voltages, polymer viscoelasticity minimally affects the ohmic and limiting regions, but under convection-dominated flow, different rheological parameters, such as the viscosity ratio, Weissenberg number, anisotropic parameter, and electrohydrodynamic coupling constants, enable controllable regulation of ion transport behavior across a wide range. Finally, this paper states that modulated electroosmosis by complex charged polymers is the future cutting edge. The relevant results supplement the non-Newtonian physics of electrokinetic systems and provide guidance for the design and operation of microfluidic devices.
Propagation properties of two types of sinc Schell-model beams in oceanic turbulence
Authors: Tian Liancheng , Zhou Jianyang
Published: November 2024

The evolution of two types of sinc Schell-model (SSM) beams, each considered with both circular and rectangular symmetries, is investigated during their propagation in oceanic turbulence. The expressions for the spectral intensity and spectral coherence of the transmitted optical field are derived using the extended Huygens–Fresnel principle. Based on these expressions, numerical simulations are carried out to explore how source and turbulence parameters influence the transmitted field. The results demonstrate that the spectral intensity distribution of the SSM1 beam evolves from an initial Gaussian profile into a circular or rectangular flat-topped shape during propagation, while the SSM2 beam develops into a ring-shaped or array-like pattern. As the dissipation rate of turbulent kinetic energy decreases, or the mean square temperature dissipation rate and the strength of temperature and salinity fluctuations increase, the energy of these beams disperses from its concentrated regions to the surrounding areas, causing the characteristic intensity distributions to become blurred. Additionally, the coherence of these beams exhibits oscillatory distributions, with the SSM2 beam showing stronger oscillations compared to the SSM1 beam and displaying greater sensitivity to changes in turbulence parameters. The intensity and coherence distributions are also affected by source parameters, which play a dominant role at shorter propagation distances. However, as the distance increases, turbulence parameters gradually become the primary influence. The results presented here may be applied to oceanic optical communication and remote sensing.
Electron scattering study on acetic acid and methyl formate
Authors: Bhavsar Nirali , Vinodkumar P C , Mason Nigel , Vinodkumar Minaxi
Published: November 2024

In this work we report the results of a theoretical calculation of the elastic, differential scattering, and excitation cross-sections on electron interactions with the C2H4O2 isomers (methyl formate and acetic acid) using the ab initio R-matrix method in the energy range of 0.1–20 eV. The computations were performed using static exchange (SE), static exchange plus polarization (SEP) and Close-Coupling (CC) models with electronic structure calculation for these molecules performed using GAMESS. In the electron scattering cross section we have identified π* type resonance in both the isomers. Ionization cross-sections for both the molecules from ionization threshold to 500 eV using BEB method are also presented here. We endeavoured to explore the isomeric effect on various cross sections among these two isomers and included the third isomer, namely glycolaldehyde, as reported in our previous publication.
Improvement of the magnetization and heating ability of CoFe2O4/NiFe2O4 core/shell nanostructures
Authors: Zonkol Maram G , Faramawy A M , Allam Nageh K , El-Sayed H M
Published: November 2024

In this study, the effect of the shell thickness on the structural and magnetic properties of the CoFe2O4/NiFe2O4 core/shell is studied. A single-phase core/shell nanocomposite was prepared by the hydrothermal method. The shell thickness was found to control the magnitudes of saturation magnetization and coercive field of the prepared samples. The thickness of the NiFe2O4, which covered cubic CoFe2O4 particles of 15 nm, was 1.8 nm, leading to an increase in the saturation magnetization by 26% and a decrease in the coercive field by 50% compared to bare CoFe2O4. However, a further increase in shell thickness caused interfacial dislocations due to the lattice mismatch between the core and the shell. Finally, specific absorption rate (SAR) at high frequency was measured for all samples. Comparing the temperature rise under the influence of AC magnetic field, which indicates power loss, relative to bare CoFe2O4, it was enhanced by 100% for a shell thickness of 26 nm. The results of this study point to potential applications for these samples in the field of magnetic hyperthermia for cancer therapy and drug delivery.
Indium oxide thick-films decorated with PdO and PtO2 particles for oxygen detection in humid environments
Authors: Sari Wangi P , Rifai Achmad P , Smith Peter , Agbroko Samuel O , Covington James
Published: November 2024

Thick film indium oxide chemiresistive sensors decorated with PdO and PtO2 particles were investigated for oxygen detection under humid conditions (tested ranging from 20%–80% RH) across a temperature range of 50 °C to 400 °C. The PtO2-decorated In2O3 sensors demonstrated a significantly higher response to oxygen, showing a 500% increase at 200 °C compared to the PdO-decorated sensors (response values of 41 and 8, respectively). Tests in dry air were conducted to assess the effect of humidity on sensor performance, revealing a maximum response of 74 for PtO2-In2O3 at 400 °C, more than three times higher than the response of 22 for PdO-In2O3. Selectivity tests confirmed that the sensors responded more strongly to oxygen than to interfering gases. The integration of an active carbon cloth (ACC) filter effectively reduced interferences from isobutylene and ethylene, enhancing sensor’s selectivity. A comparison of both sensors demonstrated that PtO2-decorated In2O3 has greater potential as an alternative to existing Pb-based electrochemical oxygen sensors, particularly in humid environments.
An indirect geometry crystal time-of-flight spectrometer for FRM II
Authors: Tang Ran , Herb Christoph , Voigt Jörg , Georgii Robert
Published: November 2024

We present a concept for an indirect geometry crystal
time-of-flight spectrometer, which we propose for a source similar
to the FRM-II reactor in Garching. Recently, crystal analyzer
spectrometers at modern spallation sources have been proposed and
are under construction. The secondary spectrometers of these
instruments are evolutions of the flat cone multi-analyzer for
three-axis spectrometers (TAS). The instruments will provide
exceptional reciprocal space coverage and intensity to map out the
excitation landscape in novel materials. We will discuss the
benefits of combining a time-of-flight primary spectrometer with a
large crystal analyzer spectrometer at a continuous neutron source.
The dynamical range can be very flexibly matched to the requirements
of the experiment without sacrificing the neutron intensity. At the
same time, the chopper system allows a quasi-continuous variation of
the initial energy resolution. The neutron delivery system of the
proposed instrument is based on the novel nested mirror optics,
which images neutrons from the position of the pulse cutting chopper
representing a bright virtual source onto the sample. The spot size
of less than 1 cm × 1 cm at the virtual source
allows the realization of very short neutron pulses by the choppers,
while the small and well-defined spot size at the sample position
provides an excellent energy resolution of the secondary
spectrometer.
First results on new helium based eco-gas mixtures for the Extreme Energy Events Project
Authors: Abbrescia M. , Avanzini C. , Baldini L. , Baldini Ferroli R. , Batignani G. , Battaglieri M. , Boi S. , Bossini E. , Carnesecchi F. , Cavazza F. , Cicalò C. , Cifarelli L. , Coccetti F. , Coccia E. , Corvaglia A. , De Gruttola D. , De Pasquale S. , Galante L. , Garbini M. , Gnesi I. , Gramegna F. , Grazzi S. , Hatzifotiadou D. , La Rocca P. , Liu Z. , Mandaglio G. , Margotti A. , Maron G. , Mazziotta M.N. , Mulliri A. , Nania R. , Noferini F. , Nozzoli F. , Palmonari F. , Panareo M. , Panetta M.P. , Paoletti R. , Pellegrino C. , Perasso L. , Pinazza O. , Pinto C. , Pisano S. , Riggi F. , Righini G. , Ripoli C. , Rizzi M. , Sartorelli G. , Scapparone E. , Schioppa M. , Scioli G. , Scribano A. , Selvi M. , Taiuti M. , Terreni G. , Trifirò A. , Trimarchi M. , Vistoli C. , Votano L. , Williams M.C.S. , Zichichi A. , Zuyeuski R. ,   The EEE collaboration
Published: November 2024

The Extreme Energy Events (EEE) Project, a joint project of the Centro Fermi (Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”) and INFN, has a dual purpose: a scientific research program on cosmic rays at ground level and an intense outreach and educational program. The project consists in a network of about 60 tracking detectors, called telescopes, mostly hosted in Italian High Schools. Each telescope is made by three Multigap Resistive Plate Chambers, operated so far with a gas mixture composed by 98% C2H2F4 and 2% SF6. Due to its high Global Warming Potential, a few years ago the EEE collaboration has started an extensive R&D on alternative mixtures environmentally sustainable and compatible with the current experimental setup and operational environment. Among other gas mixtures, the one with helium and hydrofluoroolefin R1234ze gave the best result during the preliminary tests performed with two of the network telescopes. The detector has proved to reach performance levels comparable to those obtained with previous mixtures, without any modification of the hardware. We will discuss the first results obtained with the new mixture, tested with different percentages of the two components.
Reproducing the caress gesture with an anthropomorphic robot: a feasibility study
Authors: Lapresa Martina , Lauretti Clemente , Cordella Francesca , Reggimenti Andrea , Zollo Loredana
Published: November 2024

Social robots have been widely used to deliver emotional, cognitive and social support to humans. The exchange of affective gestures, instead, has been explored to a lesser extent, despite phyisical interaction with social robots could provide the same benefits as human-human interaction. Some studies that explored the touch and hugs gestures were found in literature, but there are no studies that investigate the possibility of delivering realistic caress gestures, which are, in turn, the easiest affective gestures that could be delivered with a robot. The first objective of this work was to study the kinematic and dynamic features of the caress gesture by conducting experimental acquisitions in which ten healthy volunteers were asked to caress the cheek of a mannequin in two conditions, i.e. standing and sitting. Average motion and force features were then analyzed and used to generate a realistic caress gesture with an anthropomorphic robot, with the aim of assessing the feasibility of reproducing the caress gesture with a robotic device. In addition, twenty-six healthy volunteers evaluated the anthropomorphism and perceived safety of the reproduced affective gesture by answering the Godspeed Questionnaire Series and a list of statements on the robot motion. The gesture reproduced by the robot was similar to the caress gesture performed by healthy volunteers both in terms of hand trajectory and orientation, and exchanged forces. Overall, volunteers perceived the robot motion as safe and positive emotions were elicited. The proposed approach could be adapted to humanoid robots to improve the perceived anthropomorphism and safety of the caress gesture.