bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical investigation on solids settling in a non-Newtonian slurry inside a horizontal flume
Authors: Sharma Shubham , Sontti Somasekhara Goud , Zhang Wenming , Nikrityuk Petr , Zhang Xuehua
Published: July 2024

Slurry transportation is always crucial for many industrial processes. This study numerically investigates the settling behavior of multisize solid particles in a non-Newtonian slurry inside a semicircular open channel (flume). The non-Newtonian slurry is modeled using a three-dimensional unsteady Eulerian–Eulerian (E–E) model coupled with the Hershel–Bulkley rheological model. A detailed sensitivity analysis of drag models is performed to establish the solid–fluid interaction in the slurry flow. The numerical model is validated with the experimental data from the literature and shows a fair agreement. The validated model is used to simulate the settling behavior of the slurry in the flume. The mean particle diameter of the solid particles in the slurry is in the range of 75–296 μm with a median diameter of 188 μm. The effect of particle size distributions (PSDs), flume inclination, bubble size, and bubble volume fraction on the particle settling inside the flume is investigated in the parametric study. The analysis of our results revealed that the settling of solids is significantly affected by PSDs in the open channel system. In particular, the increase in flume inclination progresses the settling and dissipation of fine and coarse particles, respectively. Additional simulations showed that the inception of bubbles influences the settling velocity of solids, which changes the settling behavior of multisize solids inside the flume. The presented study can be used as a valuable guideline for the optimization of intermediate exclusion of water from thickened slurry in order to ensure the stability of tailing storage facility.
Integrated workflows and interfaces for data-driven semi-empirical electronic structure calculations
Authors: Stishenko Pavel , McSloy Adam , Onat Berk , Hourahine Ben , Maurer Reinhard J. , Kermode James R. , Logsdail Andrew
Published: July 2024

Modern software engineering of electronic structure codes has seen a paradigm shift from monolithic workflows toward object-based modularity. Software objectivity allows for greater flexibility in the application of electronic structure calculations, with particular benefits when integrated with approaches for data-driven analysis. Here, we discuss different approaches to create deep modular interfaces that connect big-data workflows and electronic structure codes and explore the diversity of use cases that they can enable. We present two such interface approaches for the semi-empirical electronic structure package, DFTB+. In one case, DFTB+ is applied as a library and provides data to an external workflow; in another, DFTB+receives data via external bindings and processes the information subsequently within an internal workflow. We provide a general framework to enable data exchange workflows for embedding new machine-learning-based Hamiltonians within DFTB+ or enabling deep integration of DFTB+ in multiscale embedding workflows. These modular interfaces demonstrate opportunities in emergent software and workflows to accelerate scientific discovery by harnessing existing software capabilities.
A compact acoustic metamaterial based on Helmholtz resonators with side slits for low-frequency sound absorption
Authors: Chen Xingyu , Sun Feiyang , Zhang Jing , Chen Gaorui , Xu Liyue , Fan Li , Cheng Liping , Xu Xiaodong , Chen Yunteng , Zhou Jiexin , Li Liangping , Yang Shaoping
Published: July 2024

The advancement of acoustic metamaterials enables the highly efficient absorption of low-frequency noise with a subwavelength structure thickness, but the complexity of these structures often hinders their large-scale practical applications. Here, we propose a straightforward and compact acoustic metamaterial structure composed of Helmholtz resonators with side slits (HRSS) for low-frequency noise absorption. The introduction of side slits not only simplifies the overall structure but also allows for easy adjustment of acoustic characteristics. By adjusting the depth of the resonator within the slit across 25 distinct units, an absorption coefficient above 0.8 is realized from 470 to 930 Hz. This work demonstrates the extensive low-frequency sound absorption capability of HRSS, providing valuable insights into the design of future practical acoustic materials.
Topological Hall effect in a non-magnetic metal interfaced to a canted antiferromagnetic insulator in perovskite oxide heterostructures
Authors: Fujita Takahiro C. , Omura Koki , Kawasaki Masashi
Published: July 2024

We report interfacial transport properties in in situ grown orthorhombic perovskite oxide heterostructures consisting of an antiferromagnetic insulator DyFeO3 and a paramagnetic conductor CaRuO3. We observe Hall effect with a step-like increase amounting to an effective magnetic field of 30 T at 20 K. We provide a plausible explanation in the context of topological Hall effect originating from a non-coplanar spin texture and resultant emergent field in DyFeO3 associated with the scalar spin chirality. Our results demonstrate that the proximity effect of the emergent field at heterointerfaces is a universal physical phenomenon, while it has been reported originally in a heterointerface composed of pyrochlore oxides. This will greatly expand the choice of materials to the heterointerfaces for the research in emergent transport phenomena, which has been limited to single compounds with both metallic properties and special spin textures. Additionally, this will pave the way for possible device application of the emergent field by designing and combining perovskite oxides with versatile functionalities such as multiferroicity.
Large eddy simulation of a supersonic lifted hydrogen flame: Impacts of Lewis, turbulent Schmidt and Prandtl numbers
Authors: Zhu Ruixuan , Huang Zhiwei , Xu Chao , Fang Xiaohang , Zhang Huangwei , Davy Martin
Published: July 2024

Parametric large eddy simulations (LES) of a supersonic lifted hydrogen flame are reported. The emphases are on two aspects: impacts of (1) Lewis number (Lei of the ith species) and (2) turbulent Schmidt and Prandtl numbers (Sct and Prt) on supersonic turbulent flame and flow structures. Five cases are considered: species-specific Lei, Sct=Prt=1.0 (C0); unity Lei, Sct=Prt=1.0 (C1); species-specific Lei, Sct=0.5, Prt=1.0 (C2); species-specific Lei, Sct=1.0, Prt=0.5 (C3); and species-specific Lei, Sct=Prt=0.5 (C4). Numerical results of instantaneous and/or time-averaged species mole fractions, mixture fraction, heat release rate, flame base location, and mixed modes of premixed and diffusion combustion are compared between cases C0 and C1. Differences in auto-ignition locations and strengths and flame structures and stabilization specify the impacts of Lewis number. They are triggered by different predictions of species mass and thermal diffusions at fuel-coflow and/or coflow-ambient air mixing layers. These differences are rationalized by a scale analysis of mass/thermal diffusion and convection for case C0, which suggests the relatively low but non-negligible former against the latter. Cases C0 and C2–C4 barely see differences in terms of instantaneous and/or time-averaged temperature, velocity, and mixed combustion modes except for further downstream areas where combustion occurs. Both Sct and Prt impose less significant influences than Lewis number, as sub-grid scale mass/thermal diffusion is subordinate to its resolved counterpart according to their scale analysis for case C4.
Vortical structures and passive scalar transport in starting process of annular purging jet
Authors: Cao Jian , Wang Peng , Liu Hong , Wang Benlong , Liu Yingzheng
Published: July 2024

The evolution of vortical structures and passive scalar transport in the starting process of annular purging jets are numerically investigated by large eddy simulation. Three flow configurations with different nozzle-to-plate distances at a fixed radius ratio of 0.71 and the Reynolds number of 13 750 are simulated. The numerical results are validated against documented experimental data. Three stages during the evolution are proposed based on instantaneous flow visualizations and assessed by calculating the circulation changes of the annular jets and vortex rings. The vortical structures are identified to understand the three-dimensional characteristics. The entrainment process is analyzed focusing on the passive scalar transport in the flow fields and is correlated with the cleaning performance of annular purging jets. The flow structures dominate the process of scalar mixing, especially the inner and outer vortex rings. The large-scale motions of trailing jets cause the intermittent events of scalar transport. During the starting process, the cleaning performance is better with a smaller nozzle-to-plate distance, while the cleaning efficiency may reach the optimum at a moderate distance. The cleaning process is limited by the scalar diffusion and entrainment process. These findings highlight the significance of flow structures for effective cleanness of temperature and contaminations in the purging systems.
Peculiarities of spin–orbit interaction systematically measured in FeCoB nanomagnets
Authors: Zayets Vadym
Published: July 2024

This study introduces a method to measure the strength of spin–orbit interaction (SO) in a nanomagnet, investigating fundamental phenomena governing magnetic anisotropy. The method explores the fundamental property of SO in its linear proportionality to the external magnetic field, a relationship validated through experimental observation. Systematic study of SO in FeCoB nanomagnets reveals distinct SO behaviors in bulk and at an interface, substantial disparities in single- and multi-layer nanomagnets, intriguing periodic oscillations in SO strength, and the systematic relationship between SO strength, demagnetization field, and magnetic anisotropy based on surface imperfections. These findings provide crucial insights into diverse SO interaction behaviors, crucial for understanding and optimizing magnetic anisotropy and nanomagnet properties.
Effect of pressure on microstructure and properties of Ti–Al coating on titanium alloy surface
Authors: Wei Xu , Yong Li , Jingfei Bai , Hu Du , Qing Su , RuTao Xu , Hong Liu , Dan Yu
Published: July 2024

The effect of pressure on the microstructure and properties of Ti–Al coating on titanium alloy surface is studied. Ti–Al coating is prepared on the surface of titanium alloy by pressure-assisted high-temperature thermal diffusion. The manufacturing method is simple and easy to operate. The microstructure and element distribution of the coating are analyzed under different processes, and the composition of the coating is tested. The test results show that the substrate alloy and the coating alloy are not connected when the coating is diffused at 650 °C. The coating diffused at 750 °C without pressure is mostly connected to the substrate, but there are microscopic gaps in some areas. The main components of the coating diffused at 750 °C under 80 Pa pressure are TiAl, Ti3Al, and other intermetallic compounds. The boundary between the substrate and the coating is flat, and there is no obvious micro gap, so the metallurgical connection is fundamentally realized. In addition, the maximum hardness can reach 334.9HV0.2. The thickness of the coating diffused at 750 °C under 160 Pa pressure was greatly reduced, showing a gradient form. The surface quality of the outer coating is poor, the structure density of the binding layer is also poor, and there are no obvious penetrating cracks. The bonding between the coating and the substrate is effectively enhanced by an auxiliary action under certain pressure, and then the microstructure and properties of the coating are improved.
A nanofluidic spiking synapse
Authors: Xu Yi-Tong , Yu Si-Yuan , Li Zheng , Kou Bo-Han , Pang Jian-Xiang , Zhao Wei-Wei , Chen Hong-Yuan , Xu Jing-Juan
Published: July 2024

Currently, the nanofluidic synapse can only perform basic neuromorphic pulse patterns. One immediate problem that needs to be addressed to further its capability of brain-like computing is the realization of a nanofluidic spiking device. Here, we report the use of a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate membrane to achieve bionic ionic current-induced spiking. In addition to the simulation of various electrical pulse patterns, our synapse could produce transmembrane ionic current-induced spiking, which is highly analogous to biological action potentials with similar phases and excitability. Moreover, the spiking properties could be modulated by ions and neurochemicals. We expect that this work could contribute to biomimetic spiking computing in solution.
Structural and mechanistic analysis of Ca
2+
-dependent regulation of transglutaminase 2 activity using a Ca
2+
-bound intermediate state
Authors: Sewa Agnele S. , Besser Harrison A. , Mathews Irimpan I. , Khosla Chaitan
Published: July 2024

Mammalian transglutaminases, a family of Ca
2+
-dependent proteins, are implicated in a variety of diseases. For example, celiac disease (CeD) is an autoimmune disorder whose pathogenesis requires transglutaminase 2 (TG2) to deamidate select glutamine residues in diet-derived gluten peptides. Deamidation involves the formation of transient γ-glutamyl thioester intermediates. Recent studies have revealed that in addition to the deamidated gluten peptides themselves, their corresponding thioester intermediates are also pathogenically relevant. A mechanistic understanding of this relevance is hindered by the absence of any structure of Ca
2+
-bound TG2. We report the X-ray crystallographic structure of human TG2 bound to an inhibitory gluten peptidomimetic and two Ca
2+
ions in sites previously designated as S1 and S3. Together with additional structure-guided experiments, this structure provides a mechanistic explanation for how S1 regulates formation of an inhibitory disulfide bond in TG2, while also establishing that S3 is essential for γ-glutamyl thioester formation. Furthermore, our crystallographic findings and associated analyses have revealed that i) two interacting residues, H305 and E363, play a critical role in resolving the thioester intermediate into an isopeptide bond (transamidation) but not in thioester hydrolysis (deamidation); and ii) residues N333 and K176 stabilize preferred TG2 substrates and inhibitors via hydrogen bonding to nonreactive backbone atoms. Overall, the intermediate-state conformer of TG2 reported here represents a superior model to previously characterized conformers for both transition states of the TG2-catalyzed reaction.
Subtle dynamics of the chaotic torsion pendulum: a detailed comparison between experiments and numerical simulations
Authors: Xie Guijin , Yan Zixiang , Gao Jian , Yang Hujiang , Lan Yueheng , Xiao Jinghua
Published: July 2024

We conduct a detailed experimental and numerical study on the subtle dynamics of the chaotic torsion pendulum (CTP). We first present experimental observations reported by students, and then propose a revised model of CTP based on laws of mechanics and insights about the experiment to understand these observations. Parameters of the revised model are fit using experimental data. The revised model agrees well with experimental observations. The subtle dynamics hidden in these phenomena, from the parameter sensibility to the influences of bisability, are thoroughly exhibited throughout this study, which we hope provides more insight into the nonlinear nature of CTP.
Evolution of level population in Ar interacting with XFEL pulses: impact of resonant absorptions
Authors: Yan Jie , Yan Guanpeng , Jin Fengtao , Li Yongjun , Gao Cheng , Zeng Jiaolong , Yuan Jianmin
Published: July 2024

Theoretical exploration of the population dynamics at fine-structure levels of Ar atoms interacting with ultrafast ultraintense x-ray free electron laser (XFEL) pulses is conducted. A time-dependent rate equation based on a detailed-level accounting approach is applied for tracking population levels, encompassing microscopic atomic processes such as photoexcitation, radiative decay, photoionization and Auger decay. A Monte Carlo algorithm is implemented to solve large-scale rate equations efficiently. The primary investigation centers on generating Ar17+ through resonant absorption by the second-harmonic radiation of the x-ray pulse. The calculated population ratios of Ar17+ to Ar16+ align well with the experimental measurements (LaForge et al 2021 Phys. Rev. Lett.
127 213202). In comparison to the transition energy of the strongest line,

(
1

s
2

)
0

→
(
1

s

1

/

2

2

p

3

/

2

)
1

of Ar16+, there is a distinct ∼25 eV red shift in the peak ratio, which is attributed to the presence of intricate resonant channels in the lower ionization stages. The results demonstrate the sensitivity of the population ratio Ar17+/Ar16+ to the laser pulse parameters such as x-ray pulse duration, bandwidth and the contribution of second-harmonic radiation, indicating their potential as diagnostic tools in future experiments.
Magnetization dynamics in quasiperiodic magnonic crystals
Authors: Mehta Riya , Rana Bivas , Saha Susmita
Published: July 2024

Quasiperiodic magnonic crystals, in contrast to their periodic counterparts, lack strict periodicity which gives rise to complex and localised spin wave spectra characterized by numerous band gaps and fractal features. Despite their intrinsic structural complexity, quasiperiodic nature of these magnonic crystals enables better tunability of spin wave spectra over their periodic counterparts and therefore holds promise for the applications in reprogrammable magnonic devices. In this article, we provide an overview of magnetization reversal and precessional magnetization dynamics studied so far in various quasiperiodic magnonic crystals, illustrating how their quasiperiodic nature gives rise to tailored band structure, enabling unparalleled control over spin waves. The review is concluded by highlighting the possible potential applications of these quasiperiodic magnonic crystals, exploring potential avenues for future exploration followed by a brief summary.
Data driven surrogate signal extraction for dynamic PET using selective PCA: time windows versus the combination of components
Authors: Whitehead Alexander C , Su Kuan-Hao , Emond Elise C , Biguri Ander , Brusaferri Ludovica , Machado Maria , Porter Joanna C , Garthwaite Helen , Wollenweber Scott D , McClelland Jamie R , Thielemans Kris
Published: July 2024

Objective. Respiratory motion correction is beneficial in positron emission tomography (PET), as it can reduce artefacts caused by motion and improve quantitative accuracy. Methods of motion correction are commonly based on a respiratory trace obtained through an external device (like the real time position management system) or a data driven method, such as those based on dimensionality reduction techniques (for instance principal component analysis (PCA)). PCA itself being a linear transformation to the axis of greatest variation. Data driven methods have the advantage of being non-invasive, and can be performed post-acquisition. However, their main downside being that they are adversely affected by the tracer kinetics of the dynamic PET acquisition. Therefore, they are mostly limited to static PET acquisitions. This work seeks to extend on existing PCA-based data-driven motion correction methods, to allow for their applicability to dynamic PET imaging. Approach. The methods explored in this work include; a moving window approach (similar to the Kinetic Respiratory Gating method from Schleyer et al (2014)), extrapolation of the principal component from later time points to earlier time points, and a method to score, select, and combine multiple respiratory components. The resulting respiratory traces were evaluated on 22 data sets from a dynamic [18F]-FDG study on patients with idiopathic pulmonary fibrosis. This was achieved by calculating their correlation with a surrogate signal acquired using a real time position management system. Main results. The results indicate that all methods produce better surrogate signals than when applying conventional PCA to dynamic data (for instance, a higher correlation with a gold standard respiratory trace). Extrapolating a late time point principal component produced more promising results than using a moving window. Scoring, selecting, and combining components held benefits over all other methods. Significance. This work allows for the extraction of a surrogate signal from dynamic PET data earlier in the acquisition and with a greater accuracy than previous work. This potentially allows for numerous other methods (for instance, respiratory motion correction) to be applied to this data (when they otherwise could not be previously used).
ReMAR: a preoperative CT angiography guided metal artifact reduction framework designed for follow-up CTA of endovascular coiling
Authors: Zhang Yaoyu , Liu Lunxin , Yu Hui , Wang Tao , Zhang Yi , Liu Yan
Published: July 2024

Objective. Follow-up computed tomography angiography (CTA) is necessary for ensuring occlusion effect of endovascular coiling. However, the implanted metal coil will introduce artifacts that have a negative spillover into radiologic assessment. Method. A framework named ReMAR is proposed in this paper for metal artifacts reduction (MARs) from follow-up CTA of patients with coiled aneurysms. It employs preoperative CTA to provide the prior knowledge of the aneurysm and the expected position of the coil as a guidance thus balances the metal artifacts removal performance and clinical feasibility. The ReMAR is composed of three modules: segmentation, registration and MAR module. The segmentation and registration modules obtain the metal coil knowledge via implementing aneurysms delineation on preoperative CTA and alignment of follow-up CTA. The MAR module consisting of hybrid convolutional neural network- and transformer- architectures is utilized to restore sinogram and remove the artifact from reconstructed image. Both image quality and vessel rendering effect after metal artifacts removal are assessed in order to responding clinical concerns. Main results. A total of 137 patients undergone endovascular coiling have been enrolled in the study: 13 of them have complete diagnosis/follow-up records for end-to-end validation, while the rest lacked of follow-up records are used for model training. Quantitative metrics show ReMAR significantly reduced the metal-artifact burden in follow-up CTA. Qualitative ranks show ReMAR could preserve the morphology of blood vessels during artifact removal as desired by doctors. Significance. The ReMAR could significantly remove the artifacts caused by implanted metal coil in the follow-up CTA. It can be used to enhance the overall image quality and convince CTA an alternative to invasive follow-up in treated intracranial aneurysm.
Automatic planning for functional lung avoidance radiotherapy based on function-guided beam angle selection and plan optimization
Authors: Xiong Tianyu , Zeng Guangping , Chen Zhi , Huang Yu-Hua , Li Bing , Zhou Dejun , Liu Xi , Sheng Yang , Ren Ge , Wu Qingrong Jackie , Ge Hong , Cai Jing
Published: July 2024

Objective. This study aims to develop a fully automatic planning framework for functional lung avoidance radiotherapy (AP-FLART). Approach. The AP-FLART integrates a dosimetric score-based beam angle selection method and a meta-optimization-based plan optimization method, both of which incorporate lung function information to guide dose redirection from high functional lung (HFL) to low functional lung (LFL). It is applicable to both contour-based FLART (cFLART) and voxel-based FLART (vFLART) optimization options. A cohort of 18 lung cancer patient cases underwent planning-CT and SPECT perfusion scans were collected. AP-FLART was applied to generate conventional RT (ConvRT), cFLART, and vFLART plans for all cases. We compared automatic against manual ConvRT plans as well as automatic ConvRT against FLART plans, to evaluate the effectiveness of AP-FLART. Ablation studies were performed to evaluate the contribution of function-guided beam angle selection and plan optimization to dose redirection. Main results. Automatic ConvRT plans generated by AP-FLART exhibited similar quality compared to manual counterparts. Furthermore, compared to automatic ConvRT plans, HFL mean dose, V
20, and V
5 were significantly reduced by 1.13 Gy (p < .001), 2.01% (p < .001), and 6.66% (p < .001) respectively for cFLART plans. Besides, vFLART plans showed a decrease in lung functionally weighted mean dose by 0.64 Gy (p < .01), fV
20 by 0.90% (p = 0.099), and fV
5 by 5.07% (p < .01) respectively. Though inferior conformity was observed, all dose constraints were well satisfied. The ablation study results indicated that both function-guided beam angle selection and plan optimization significantly contributed to dose redirection. Significance. AP-FLART can effectively redirect doses from HFL to LFL without severely degrading conventional dose metrics, producing high-quality FLART plans. It has the potential to advance the research and clinical application of FLART by providing labor-free, consistent, and high-quality plans.
Aerosol-based multihollow surface DBD: a promising approach for nitrogen fixation
Authors: Fujera Jiří , Homola Tomáš , Jirásek Vít , Ondráček Jakub , Tarabová Barbora , Prukner Václav , Šimek Milan
Published: July 2024

Nonthermal plasma reactors, which enable electrical discharges to be generated in various gases and both liquid and gaseous water, have attracted considerable attention as an alternative method for producing ammonia and fixing nitrogen. In this work, we investigated the basic performance of multihollow surface dielectric barrier discharge (MSDBD) to generate plasma in synthetic air and nitrogen-containing admixtures of water aerosols. The MSDBD in combination with the aerosol stream represents a rather complex geometry for generating the discharge; the plasma is significantly affected by the physicochemical properties of water aerosols on the one hand, on the other hand, this system facilitates the solvation of gaseous plasma products in water and the production of plasma-activated nitrogen-rich water (PAW). The plasma interaction with the water aerosols was studied using optical emission spectroscopy and a scanning mobility particle sizer to provide information about the size and distribution of the water particles entering and exiting the plasma reactor. The gas exiting the plasma reactor was analyzed using Fourier-transform infrared spectroscopy, and the PAW collected in an ice-cooled vessel was analyzed for nitrates (NO2
−), nitrites (NO3
−), and ammonia (NH3). MSDBD shows promise as a catalyst- and H2-free method for fixing nitrogen in water. Additionally, given the low energy consumption (<5 W) of MSDBD and the straightforward construction of the plasma unit, the suggested approach for PAW production offers a viable route for advancing a decentralized sustainable economy.
Continuous and deterministic all-photonic cluster state of indistinguishable photons
Authors: Su Zu-En , Taitler Boaz , Schwartz Ido , Cogan Dan , Nassar Ismail , Kenneth Oded , Lindner Netanel H , Gershoni David
Published: July 2024

Cluster states are key resources for measurement-based quantum information processing. Photonic cluster and graph states, in particular, play indispensable roles in quantum network and quantum metrology. We demonstrate a semiconductor quantum dot based device in which the confined hole spin acts as a needle in a quantum knitting machine producing continuously and deterministically at sub-Gigahertz repetition rate single indistinguishable photons which are all polarization entangled to each other and to the spin in a one dimensional cluster state. By projecting two nonadjacent photons onto circular polarization bases we disentangle the spin from the photons emitted in between. This way we demonstrate a novel way for producing deterministic and continuous all-photonic cluster states. We use polarization tomography on four sequentially detected photons to demonstrate and to directly quantify the robustness of the cluster’s entanglement and the determinism in its photon generation.
Gaussian quantum metrology for mode-encoded parameters
Authors: Sorelli Giacomo , Gessner Manuel , Treps Nicolas , Walschaers Mattia
Published: July 2024

Quantum optical metrology aims to identify ultimate sensitivity bounds for the estimation of parameters encoded into quantum states of the electromagnetic field. In many practical applications, including imaging, microscopy, and remote sensing, the parameter of interest is not only encoded in the quantum state of the field, but also in its spatio-temporal distribution, i.e. in its mode structure. In this mode-encoded parameter estimation setting, we derive an analytical expression for the quantum Fisher information valid for arbitrary multimode Gaussian fields. To illustrate the power of our approach, we apply our results to the estimation of the transverse displacement of a beam and to the temporal separation between two pulses. For these examples, we show how the estimation sensitivity can be enhanced by adding squeezing into specific modes.
Metasurface loaded dual band antenna for high gain on- and off- body communication
Authors: Ali Esraa Mousa , Islam Tanvir , Awan Wahaj Abbas , Alzaidi Mohammed S. , Alkanhel Reem , Elkamchouchi Dalia H
Published: July 2024

Metasurfaces are specially made materials designed to have unique properties not found in nature. They are categorized into different types, such as artificial magnetic conductor (AMC), partial reflecting surfaces (PRS), and frequency selective surfaces (FSS). Among these, FSS is commonly used in today’s technology to improve antenna performance, especially in boosting signal strength by blocking unwanted radiation. Recent research is focused on creating FSS-based antennas for Ultra-wideband (UWB) or single band applications, with a significant emphasis on enhancing signal strength. Unlike traditional methods, this study concentrates on designing antennas that are both simple in shape and offers broader frequency coverage, specifically for 2.45 GHz and 5.8 GHz applications. To enhance antenna performance, a dual-band FSS is employed, optimizing the system for improved operation at both resonating frequencies. This results in a high-gain antenna system, which is further investigated for body area network (BAN) systems, considering the crucial performance metric of specific absorption rate (SAR). The findings are compared with recently reported FSS-based antennas to underscore their scientific contribution and potential for high gain, low SAR applications within the 2.45 GHz and 5.8 GHz frequency bands.
Recovery of damaged information via scrambling in indefinite causal order
Authors: Jin Tian-Ren , Li Tian-Ming , Wang Zheng-An , Xu Kai , Zhang Yu-Ran , Fan Heng
Published: July 2024

Scrambling prevents the access to local information with local operators and therefore can be used to protect quantum information from damage caused by local perturbations. Even though partial quantum information can be recovered if the type of the damage is known, the initial target state cannot be completely recovered, because the obtained state is a mixture of the initial state and a maximally mixed state. Here, we demonstrate an improved scheme to recover damaged quantum information via scrambling in indefinite causal order. We show that scheme with indefinite causal order can record information of the damage and distill the initial state from the damaged state simultaneously. It allows us to retrieve initial information versus any damage. Moreover, by iterating the schemes, the initial quantum state can be completely recovered. In addition, we experimentally demonstrate our schemes on the cloud-based quantum computer, named as Quafu. Our work proposes a feasible scheme to protect whole quantum information from damage, which is also compatible with other techniques such as quantum error corrections and entanglement purification protocols. We expect that our scheme will be useful in the both quantum information recovery from the damage and systems bench-marking.
Exploring the AC conductivity and dielectric properties of PVA films doped with Erythrosin B
Authors: Ali H A M , El-Zaidia E F M , Darwish A A A , Farid A S
Published: July 2024

Erythrosin B (EB) doped in PVA film was processed utilizing the casting procedure, and the structure was investigated via the Fourier Transformation infrared technique (FTIR). FTIR analysis presented a strong formation of intermolecular hydrogen bonds among PVA and EB hydroxyl groups (OH). Characteristic temperature and frequency variation of dielectric behavior and AC electrical conductivity for films of PVA doped with Erythrosin B were analyzed at (293–383 K) temperature and (102–106 Hz) frequency. The AC conductivity dependency indicates that the predominant conduction mechanism in PVA doped with Erythrosin B films follows the correlated barrier hopping (CBH) model. The charge carriers’ hopping involving localized states causes a relaxation process. Estimates were made for the AC conductivity activation energy and the conductivity relaxation energy. Frequency and temperature affect the dielectric constant (ε′) and the dielectric loss (ε″). The complex impedance spectrum (Z′ versus Z″) showed single semicircular arcs with a decreased radius with increasing temperature. The relaxation peaks in the electric modulus representation are clearly defined, and the relaxation period has been calculated.
Five-dimensional Myers-Perry black holes under massive scalar perturbation: bound states and quasinormal modes
Authors: Li Wenbin , Lu Kai-Peng , LiMing W , Huang Jia-Hui
Published: July 2024

The stability of five-dimensional singly rotating Myers-Perry Black Holes against massive scalar perturbations is studied. Both the quasibound states and quasinormal modes of the massive scalar field are considered. For the quasibound states, we use an analytical method to discuss the effective potential felt by the scalar field, and found that there is no potential well outside the event horizon. Thus, singly rotating Myers-Perry Black Holes are stable against the perturbation of quasibound states of massive scalar fields. Then, we use continued fraction method based on solving a seven-term recurrence relations to compute the spectra of the quasinormal modes. For different values of the black hole rotation parameter a, scalar mass parameter μ and angular quantum numbers, all found quasinormal modes are damped. Besides, when the scalar mass μ becomes relatively large, the long-living quasiresonances are also found as in other rotating black hole models. Our results complement previous arguments on the stability of five-dimensional singly rotating Myers-Perry black holes against massive scalar perturbations.
AC losses in macroscopic thin-walled superconducting cylinders
Authors: Tsindlekht M I , Genkin V M , Felner I , Zeides F , Katz N , Gazi Š , Chromik Š , Dobrovolskiy O V
Published: July 2024

Measurements of the ac response represent a valuable method for probing the properties of superconductors. In the surface superconducting state (SSS), a current exceeding the surface critical current I
c leads to breakdown of SSS and penetration of external magnetic field into the sample bulk. An interesting free-of-bulk system in SSS is offered by thin-walled cylinders. According to the full penetration of magnetic flux (FPMF) model, each time the instant value of an ac field is equal to a certain critical value, the ac susceptibility χ will exhibit jumps as a function of the ac field amplitude H
ac because of the periodic destruction and restoration of SSS in the cylinder wall. Here we study the low-frequency (128–8192 Hz) ac response of thin-walled niobium cylinders under superimposed dc and ac magnetic fields applied parallel to the cylinder axis. In contrast to the FPMF model predictions, experiments reveal a smooth
χ(H
ac) dependence. To explain the experimental observations, we propose a phenomenological partial penetration magnetic flux (PPMF) model, which assumes that after restoration of the superconducting state, the magnetic fields inside and outside the cylinder are unequal and the magnitude of the penetrating flux is random for every penetration. This model fits very well the experimental data on the temperature dependence of the first harmonic χ
1 for any dc field and ac amplitude.
Dichloro-tin (IV) hexadeca-fluoro-phthalocyanine (F16PcSnCl2) thin film on porous silicon layers by ultrasonic spray pyrolysis, for possible application in optoelectronics devices
Authors: Cuate Gomez D H , Garzón Román A , Sosa Sanchez J L , Zuñiga Islas C , Lugo J M
Published: July 2024

Phthalocyanines represent a significant class of organic semiconductors that have garnered attention for their potential applications in conducting polymers and organic electronics. The unique structural characteristics of phthalocyanines, coupled with the intriguing chemical behavior and variations in bandgap associated with different substitution sites, offer exciting prospects for designing novel application devices. In this study, we have successfully fabricated a heterostructure incorporating dichloro tin (IV) hexa deca fluoro phthalocyanine (F16PcSnCl2) on both porous silicon (PS) and crystalline silicon (c-Si). The PS substrate was prepared using metal-assisted chemical etching. To explore the optoelectronic applications, we thoroughly characterized the optical, electrical, and morphological properties of the heterostructure. F16PcSnCl2 exhibits the lowest reflectance within the visible light spectrum, making it highly advantageous for photosensitive applications that necessitate efficient light absorption, diffusion, or scattering. The morphological analysis of the F16PcSnCl2 film reveals the presence of nanosphere-type structures uniformly distributed on both PS and c-Si substrates. The absorbance spectrum exhibits three distinct bands, which serve as typical indicators of the F16PcSnCl2 complex. Several hybrid heterostructures were fabricated for electrical characterization, displaying rectifying ohmic behavior and demonstrating a photocurrent effect in the I-V curves. Notably, when the heterostructures were polarized at 1 V, a pronounced response to pulses of white light was observed in the current–time curves. Overall, the integration of organic and inorganic materials in heterostructures holds great promise for innovative applications in optoelectronics.
Fractional non-Fourier modeling of laser drilling process
Authors: Hassan Ayman F , Abidou Diaa , Elsaid A , Zahra W K
Published: July 2024

In this paper, a novel fractional non-Fourier model is employed to simulate the laser drilling process, addressing limitations inherent in classical heat conduction equations, including the well-known heat equation paradox associated with infinite heat propagation velocity. This model approach combines spatial approximation via the Meshless Local Petrov-Galerkin method with temporal approximation using the Grünwald-Letnikov finite difference scheme. The study assesses the impact of employing fractional orders, both constant and variable over time, on numerical results, and validates the model using experimental data.
Polarization independent perfect absorption of borophene metamaterials operating in the communication band
Authors: Xiang Ting , Sun Zhe , Wang Lingling , Lin Qi , Liu Gui-dong
Published: July 2024

Two-dimensional (2D) materials, such as graphene and black phosphorus, support deeply confined and tunable plasmons, making them suitable for designing absorbers with ultra-compact size and flexible manipulation. However, the operating frequency of such plasmonic absorbers is difficult to control to the communication band. Here, we propose a metamaterials composed of a borophene array, a dielectric layer and a metal reflector to achieve an optical perfect absorber near the communication wavelength of 1550 nm. In order to overcome the polarization sensitivity caused by anisotropic borophene materials, another borophene layer is introduced to achieve a polarization independent absorber, which can be attributed to the fact that the energy of the electromagnetic field is transferred between two borophene arrays as the polarization angle changes. In addition, through the modulation of carrier density, it is feasible to fine-tune the resonance wavelength of the absorber to 1330 nm, which corresponds precisely to the second communication window. This work may provide a theoretical foundation for the development of polarization independent devices, potentially broadening the scope of their applications.
Optical signals measurement of discharge plasma in air switch cabinet using a fluorescent optical fiber as the sensor
Authors: Cheng Hongtu , Hao Weidong , Zhu Xi , Fang Zhi
Published: July 2024

Air switch cabinets are widely employed in the power industry, there is, however, no reliable methods for detecting partial discharges (PDs). Because fiber optic-based sensors are easy to install and have anti-electromagnetic interference capabilities, they are well suited for PDs detection in switch cabinets with their many components and metal shell structure. In this work, corona discharge in an air switch cabinet was detected using fluorescent fiber, and the characteristics of PDs were analyzed. Furthermore, experimental investigations were conducted to explore the impact of gas pressure and fiber length on the PDs detection. The results exhibit a correlation between the aforementioned factors and the PDs’ total amplitude, maximum amplitude, number of pulses and detection limit of PD quantity. The results can provide references for the application of fluorescent optical fiber on the PD detection in air switch cabinet.
Quantization of resistivity as consequence of symmetry invariance
Authors: Lizarraga Jorge A
Published: July 2024

The Schrödinger equation for a spinless electron under the influence of a constant electromagnetic field is analyzed based on the conserved operators of the system when the magnetic field is described by Landau’s gauge. For this specific situation, the Lorentz force can be recovered if two conserved generalized momentum operators are considered: one along the x-axis and the second along the y-axis. From the general solution obtained, a time-dependent ground state is constructed characterized by quantized resistivity proportional to integer multiples of von Klitzing’s constant when an invariance condition under a unitary transform is satisfied.
Fluid models calculation of Ar/CF4 radiofrequency capacitively coupled plasmas
Authors: Elsheikh M G , Abdelsalam Y , Moslem W M , Shihab M
Published: July 2024

A fluid model is used to calculate plasma density in radiofrequency capacitively coupled plasmas (RF-CCPs), assuming geometrically symmetric Ar/CF4. Electrodes are powered by a 200 V sinusoidal wavefront at 13.56 MHz. The gap between the electrodes is 5 cm. The plasma species density is calculated as a function of the gas pressure, electron temperature, and gas composition. As expected from recent experiments,

CF

3

+

and F are dominant for all simulation parameters (Plasma Chemistry and Plasma Processing, 2022; 42: 989-1002, 2013 Pulsed Power Conference (PPC), 19th IEEE, DOI:10.1109/PPC.2013.6627595). The results explain the pathways to perform atomic layer etching and nanolayer deposition processes. In order to reveal the effect of electron heating on the discharge dynamics, the spatiotemporal electron energy equation is coupled with the fluid model. Tailoring the driven potential has been found to control the concentration of some plasma species. When the plasma is driven by the fundamental frequency, ohmic and stochastic heating allow electrons to be heated symmetrically. Higher harmonics give rise to an electrical asymmetry and an electron heating asymmetry between the powered and grounded sheaths. The electron temperature depends on the driven harmonics; it adjusts gain and loss rates and some plasma species densities.
Trigonometric Lagrange-Jacobi functions
Authors: Rampho Gaotsiwe J
Published: July 2024

This paper presents a class of trigonometric Lagrange-mesh functions constructed from the Lagrange-Jacobi functions. These functions extend the set of trigonometric Lagrange-mesh functions to beyond only those constructed directly from the sine and cosine functions. Trigonometric Lagrange-Chebyshev functions obtained from the presented trigonometric Lagrange-Jacobi functions are equivalent to known trigonometric Lagrange-Chebyshev functions constructed directly from the sine and cosine functions and generate identical matrix elements for the kinetic energy operator.
Effects of family non-universal Z ′ model in angular observables of
decays*
Authors: Farooq Nimra , Zaki Marwah , Ali Paracha M. , Bhutta Faisal Munir
Published: July 2024

We present the angular distribution of the four-fold

and

decays in the Standard Model and family non-universal

model. At the quark level, these decays are governed by the

transition. Along with different angular observables, we provide predictions of differential branching ratios, forward-backward asymmetry, and longitudinal polarization fractions of

and

mesons. Our analysis shows that the signatures of the family non-universal

model are more distinct in the observables associated with the

decay than in those associated with the

decay. Future measurements of the predicted angular observables, both at current and future high energy colliders, will provide useful complementary data required to clarify the structure of the family non-universal

model in

=

processes.
Angular distribution of products in multinucleon transfer reactions*
Authors: Le 乐 Xian-Kai 先凯 , Fan 范 Kuan 宽 , Xing 邢 Feng-Zhu 凤竹 , Guo 郭 Shu-Qing 树青 , Wang 王 Nan 楠
Published: July 2024

A method based on the dinuclear system (DNS) is proposed to describe the angular distribution of products in multinucleon transfer (MNT) reactions. By considering fluctuation effects, the angular distributions of reactions involving 136Xe+208Pb, 136Xe+209Bi, 86Kr+166Er, 84Kr+209Bi, and 84Kr+208Pb are examined, demonstrating good agreement with experimental data. Moreover, the double differential cross-sections (

and

) of reactions 136Xe+208Pb and 136Xe+209Bi are analyzed to explore the mechanism of angular distribution in MNT reactions. Additionally, the optimal angles for detecting N=126 isotopes are determined via an analysis on the influence of proton and neutron numbers of the projectiles on the angular distribution of the N=126 isotopic line. The results of this study can provide valuable insights for experimental detection.
Optimization Design of Semi-active Suspension for Vehicles Based on LQR Optimal Control
Authors: Liu Lianming , Calderon Aldrin D.
Published: July 2024

The suspension system is crucial for providing a comfortable ride and ensuring smooth driving. This article presents a random road surface model and a 1/4 vehicle two-degree-of-freedom semi-active suspension model. The optimal control performance index function was obtained by using the minimum principle, and the optimal controller for semi-active suspension was designed. Simulations were conducted in MATLAB/Simulink, using vehicle acceleration, suspension dynamic deflection, and tire dynamic deformation as evaluation indicators. The study found that the vehicle’s acceleration, suspension dynamic deflection, and tire dynamic deformation were reduced by 21.79%, 21.86%, and 9.88%, respectively, with the use of the designed semi-active suspension optimization controller. This resulted in improved driving smoothness and riding comfort.