bluuebunny/crossref_metadata_2025 huggingface dataset:
A parallel variable-fidelity algorithm for efficient constrained multi-objective aerodynamic design optimization
Authors: Zhang Yu , Wang Zhenkun , Han Zhong-Hua
Published: August 2024

Modern aerodynamic design optimization aims to discover optimal configurations using computational fluid dynamics under complex flow conditions, which is a typical expensive multi-objective optimization problem. The multi-objective evolutionary algorithm based on decomposition (MOEA/D) combined with efficient global optimization is a promising method but requires enhanced efficiency and faces limitations in its application to multi-objective aerodynamic design optimization (MOADO). To address the issues, an efficient parallel MOEA/D assisted with variable-fidelity optimization (VFO) is proposed for solving MOADO, called the MOEA/D-VFO algorithm. Variable-fidelity surrogates are built for objectives and constraints, achieving higher accuracy using fewer high-fidelity samples and a great number of low-fidelity samples. By retaining more good candidates, the sub-optimization problems defined by decomposing original objectives are capable of discovering more favorable samples using MOEA/D, which prompts optimization convergence. A constraint-handling strategy is developed by incorporating the probability of feasibility functions in the sub-optimizations. The selection of new samples for parallel evaluation is improved by filtering out poor candidates and selecting effective promising samples, which improves the feasibility and diversity of solved Pareto solutions. A Pareto front (PF) can be efficiently found in a single optimization run. The proposed approach is demonstrated by four analytical test functions and verified by two aerodynamic design optimizations of airfoils with and without constraints, respectively. The results indicate that the MOEA/D-VFO approach can greatly improve optimization efficiency and obtain the PF satisfying constraints within an affordable computational budget.
Variational minimization scheme for the one-particle reduced density matrix functional theory in the ensemble N-representability domain
Authors: Vladaj Matthieu , Marécat Quentin , Senjean Bruno , Saubanère Matthieu
Published: August 2024

The one-particle reduced density-matrix (1-RDM) functional theory is a promising alternative to density-functional theory (DFT) that uses the 1-RDM rather than the electronic density as a basic variable. However, long-standing challenges such as the lack of the Kohn–Sham scheme and the complexity of the pure N-representability conditions are still impeding its wild utilization. Fortunately, ensemble N-representability conditions derived in the natural orbital basis are known and trivial such that almost every functional of the 1-RDM is actually natural orbital functional, which does not perform well for all the correlation regimes. In this work, we propose a variational minimization scheme in the ensemble N-representable domain that is not restricted to the natural orbital representation of the 1-RDM. We show that splitting the minimization into the diagonal and off-diagonal parts of the 1-RDM can open the way toward the development of functionals of the orbital occupations, which remains a challenge for the generalization of site-occupation functional theory in chemistry. Our approach is tested on the uniform Hubbard model using the Müller and the Töws–Pastor functionals, as well as on the dihydrogen molecule using the Müller functional.
PVP-assisted synthesis of NiSnO3 firmly anchored on graphene as a high-performance lithium battery: A combination of theoretical and experimental study
Authors: Chen Junjie , Chen Yue , Zhang Ruidan
Published: August 2024

Tiny NiSnO3 nanoparticles with the assistance of polyvinylpyrrolidone (PVP) are prepared to uniformly and stably “bond” on the surface of graphene to form a stable NiSnO3/RGO-PVP structure. At the same time, the excellent performance of lithium-ion batteries (LIBs) with the use of NiSnO3/RGO-PVP structure is verified through a dual combination of experiment and theory. The resulting NiSnO3/RGO-PVP structure enhanced the performance of LIBs with high cycling stability and better rate capability; even after undergoing rate performance tests at different high current densities, the NiSnO3/RGO-PVP electrode can still reach a capacity of 624 mA h g−1 at 200 mA g−1 after 400 cycles. The superior electrochemical performance of NiSnO3/RGO-PVP nanocomposites can be attributed to the synergistic effects between tiny NiSnO3 nanoparticles synthesized with the assistance of PVP and RGO, which can be verified through first-principles calculations based on DFT. The charge transfer between NiSnO3 and RGO through an electron density difference indicates a strong interaction between the two. Meanwhile, the low adsorption energies (−3.914, −0.77, and −0.65 eV), low diffusion barriers (0.025, 0.49, and 0.141 eV), and high diffusion coefficients (1.79 × 10−3, 5.38 × 10−11, and 2.97 × 10−5 cm2 s−1) of lithium ions at three different positions indicate the excellent rate performance of the NiSnO3/RGO-PVP heterostructure, which is consistent with experimental results. This work analyzes the excellent electrochemical performance of NiSnO3/RGO-PVP from the experimental results and supports the reliability of the experimental results through theoretical calculations.
A hyper-distance-based method for hypernetwork comparison
Authors: Feng Ruonan , Xu Tao , Xie Xiaowen , Zhang Zi-Ke , Liu Chuang , Zhan Xiu-Xiu
Published: August 2024

Hypernetwork is a useful way to depict multiple connections between nodes, making it an ideal tool for representing complex relationships in network science. In recent years, there has been a marked increase in studies on hypernetworks; however, the comparison of the difference between two hypernetworks has received less attention. This paper proposes a hyper-distance (HD)-based method for comparing hypernetworks. The method is based on higher-order information, i.e, the higher-order distance between nodes and Jensen–Shannon divergence. Experiments carried out on synthetic hypernetworks have shown that HD is capable of distinguishing between hypernetworks generated with different parameters, and it is successful in the classification of hypernetworks. Furthermore, HD outperforms current state-of-the-art baselines to distinguish empirical hypernetworks when hyperedges are randomly perturbed.
The loss mechanisms and vortex dynamics of rotor platform step geometries in a low-speed research compressor stage
Authors: Yuan Yixi , Zhu Mingmin , Zhang Songan , Qiang Xiaoqing , Teng Jinfang
Published: August 2024

The construction and assembly of an axial compressor blade row introduces real geometric features, which leads to the deviation of flow characteristics from the intended design. According to the realistic assembly errors observed in the four-stage low-speed research compressor developed by Shanghai Jiao Tong University, two representative step geometries at the rotor platform were abstracted. Unsteady simulations were carried out in the stage environment to study the influence of hub discontinuities on compressor performance and loss mechanisms. The comparisons of smooth hub, elevated hub (EH), and a wedged hub (WH) demonstrated that all the step geometries resulted in increased loss inside both rotor and stator rows. The loss induced by WH was more sensitive to step heights than EH. Under the influence of forward facing step, rotor incidence was reduced and horseshoe vortex (HV) was exacerbated, leading to the accumulation and separation of low momentum fluids at the pressure side corner. This led to a redistribution of losses across the span. In the lower half span, the relative total pressure loss increased almost linearly with step heights, while in the tip region, it reduced slightly. The backward facing step generated the step corner vortices (SCV) that shed and propagated downstream. The SCV interacted with the HV and cavity leakage vortex in the stator passage. Coupled with the augmented stator inflow angle, the corner separation at the suction side was dramatically intensified and led to a significant loss increase.
Considerations for extracting moiré-level strain from dark field intensities in transmission electron microscopy
Authors: Craig Isaac M. , Van Winkle Madeline , Ophus Colin , Bediako D. Kwabena
Published: August 2024

Bragg interferometry (BI) is an imaging technique based on four-dimensional scanning transmission electron microscopy (4D-STEM) wherein the intensities of select overlapping Bragg disks are fit or more qualitatively analyzed in the context of simple trigonometric equations to determine local stacking order. In 4D-STEM based approaches, the collection of full diffraction patterns at each real-space position of the scanning probe allows the use of precise virtual apertures much smaller and more variable in shape than those used in conventional dark field imaging such that even buried interfaces marginally twisted from other layers can be targeted. With a coarse-grained form of dark field ptychography, BI uses simple physically derived fitting functions to extract the average structure within the illumination region and is, therefore, viable over large fields of view. BI has shown a particular advantage for selectively investigating the interlayer stacking and associated moiré reconstruction of bilayer interfaces within complex multi-layered structures. This has enabled investigation of reconstruction and substrate effects in bilayers through encapsulating hexagonal boron nitride and of select bilayer interfaces within trilayer stacks. However, the technique can be improved to provide a greater spatial resolution and probe a wider range of twisted structures, for which current limitations on acquisition parameters can lead to large illumination regions and the computationally involved post-processing can fail. Here, we analyze these limitations and the computational processing in greater depth, presenting a few methods for improvement over previous works, discussing potential areas for further expansion, and illustrating the current capabilities of this approach for extracting moiré-scale strain.
A mean-field theory for characterizing the closing rates of DNA origami hinges
Authors: Yeboah Isaac O. , Young Robert T. , Mosioma Mark , Sensale Sebastian
Published: August 2024

The evolution of dynamic DNA nanostructures has propelled DNA nanotechnology into a robust and versatile field, offering groundbreaking applications in nanoscale communication, drug delivery, and molecular computing. Yet, the full potential of this technology awaits further enhancement through optimization of kinetic properties governing conformational changes. In this work, we introduce a mean-field theory to characterize the kinetic behavior of a dynamic DNA origami hinge where each arm bears complementary single-stranded DNA overhangs of different lengths, which can latch the hinge at a closed conformation. This device is currently being investigated for multiple applications, being of particular interest the development of DNA-based rapid diagnostic tests for coronavirus. Drawing from classical statistical mechanics theories, we derive analytical expressions for the mean binding time of these overhangs within a constant hinge. This analysis is then extended to flexible hinges, where the angle diffuses within a predetermined energy landscape. We validate our model by comparing it with experimental measurements of the closing rates of DNA nanocalipers with different energy landscapes and overhang lengths, demonstrating excellent agreement and suggesting fast angular relaxation relative to binding. These findings offer insights that can guide the optimization of devices for specific state lifetimes. Moreover, the framework introduced here lays the groundwork for further advancements in modeling the kinetics of dynamic DNA nanostructures.
Preparation of topological crystalline insulator SnTe thin films for application of saturable absorber
Authors: Wu Zhitao , Xiao Peiyao , Chen Yueqian , Liu Wenjun , Xiao Wende
Published: August 2024

A series of topological insulators (TIs) based saturable absorbers (SAs), e.g., Bi2Se3, Bi2SeTe2, and Bi4Br4, are confirmed to exhibit excellent non-linear optical response due to the topological edge states. Here, we demonstrate how a topological crystalline insulator, SnTe thin films, can be prepared on highly oriented pyrolytic graphite and gold-plated mirrors through molecular beam epitaxy. SnTe-SAs incorporated into Er-doped fiber lasers exhibit a large modulation depth of 27.2% and accomplish mode-locking at 1558 nm with a pulse width of 319 fs, indicating preeminent nonlinear optical performance among the reported TI-based SAs. This work illuminates the preparation of SnTe thin films and demonstrates the great potential of SnTe films in ultrafast optical devices.
Small cluster formation in a free argon jet
Authors: Bykov N. Y. , Fyodorov S. A. , Gorbachev Yu. E.
Published: August 2024

A free argon jet flow accompanied by small clusters formation is studied with the direct simulation Monte Carlo method. Some near-continuum flow regimes characterized by Knudsen numbers in the 2×10−4−2×10−3 range are considered. A model for the argon clusters' growth/decay is proposed, taking into account the phase state of the clusters. The model consists of a chain of reactions leading to the clusters' formation, including the clusters' growth via triple/pair collisions of particles, and the clusters decay according to the collisional/unimolecular mechanism. The cluster size distributions in the jet far field are obtained. The results are compared with two experimental datasets. Good agreement is shown for most of the considered range of parameters. The triple particle collisions' influence on the argon clusters growth process is studied, and their important role in small cluster formation is demonstrated. It has been established that the cluster formation process is limited to an enough small spatial zone near the source outlet, of the order of several exit orifice diameters. The simulation shows a significant influence of cluster formation on the temperature and Mach number distributions, and a weak influence on the flow velocity. The formed clusters' translational temperatures and their velocities are close to the argon atoms' corresponding parameters. A non-equilibrium state, featured by a significant difference between the clusters' internal temperatures and the flow temperature, develops with distance from the source outlet.
Making molecules in cavity
Authors: Cederbaum Lorenz S. , Fedyk Jacqueline
Published: August 2024

Free molecules undergo processes with photons; in particular, they can undergo photoionization and photodissociation, which are relevant processes in nature and laboratory. Recently, it has been shown that in a cavity, the reverse process of photoionization, namely, electron capture becomes highly probable. The underlying mechanism is the formation of a hybrid resonance state. In this work, we demonstrate that the idea of enhanced reverse processes is more general. We discuss the case of the reverse process of photodissociation, namely, making a molecule out of separate atoms in a cavity. For bound electronic states, the interaction of atoms and molecules with quantum light as realized in cavities is known to give rise to the formation of hybrid light–matter states (usually called polaritons). In the scenarios discussed here, the hybrid light–matter states are resonance (metastable) states, which decay into the continuum of either electrons or of the fragments of a molecule. Resonances can substantially enhance the outcome of processes. In addition to the new resonant mechanism of molecule formation, the impact of the hybrid resonances on the scattering cross section of the atoms can be dramatic.
Mechanism of quantum yield enhancement in Si quantum dots by high-pressure water vapor annealing from single-dot studies
Authors: Lu Xi , Zhou Jingjian , Gelloz Bernard , Sychugov Ilya
Published: August 2024

High-pressure water vapor annealing (HWA) was recently demonstrated as a method that can substantially improve the photoluminescence quantum yield (PLQY) of silicon quantum dots (Si QDs) with the oxide shell. In this Letter, the mechanism of this enhancement is studied optically on a single-dot level. HWA treatment is performed on Si QDs formed on a silicon-on-insulator wafer, and their photoluminescence (PL) properties were examined before and after the treatment. Our experiments show a 2.5 time enhancement in the average blinking duty cycle of Si QDs after 2.6 MPa HWA treatment without changing the average ON-state PL intensity. This observation proves the carrier trapping process is suppressed on the HWA-built Si/SiO2 interface. We also discussed the mechanism behind the PLQY enhancement of HWA-treated Si QDs by comparing single-dot-level data to reported ensemble PL Si QDs results. HWA treatment is found to mainly brighten “grey” (not 100% efficient) QDs, a mechanism different from changing dark (non-emitting) to bright (100% efficient) Si QDs by ligand passivation.
The generalized method of separation of variables for diffusion-influenced reactions: Irreducible Cartesian tensor technique
Authors: Traytak Sergey D.
Published: August 2024

Motivated by the various applications of the trapping diffusion-influenced reaction theory in physics, chemistry, and biology, this paper deals with irreducible Cartesian tensor (ICT) technique within the scope of the generalized method of separation of variables (GMSV). We provide a survey from the basic concepts of the theory and highlight the distinctive features of our approach in contrast to similar techniques documented in the literature. The solution to the stationary diffusion equation under appropriate boundary conditions is represented as a series in terms of ICT. By means of proved translational addition theorem, we straightforwardly reduce the general boundary value diffusion problem for N spherical sinks to the corresponding resolving infinite set of linear algebraic equations with respect to the unknown tensor coefficients. These coefficients exhibit an explicit dependence on the arbitrary three-dimensional configurations of N sinks with different radii and surface reactivities. Our research contains all relevant mathematical details such as terminology, definitions, and geometrical structure, along with a step by step description of the GMSV algorithm with the ICT technique to solve the general diffusion boundary value problem within the scope of Smoluchowski’s trapping model.
Fractal study on the permeability of power-law fluid in a rough and damaged tree-like branching network
Authors: Zhang Guoying , Gao Jun , Xiao Boqi , Chen Lei , Cao Jiyin , Long Gongbo , Hu Haoran
Published: August 2024

In the field of fractal theory, the study of permeability in tree-like branching networks has always been rather popular. However, most of the studies have been focused on the permeability models of common fluids. In this study, based on fractal theory and the theory of power-law fluid, a fractal model of the permeability of power-law fluid in a damaged tree-like branching network considering roughness is derived. This study discusses the effects of power-law index, roughness level, damage degree, branching layer number, and length ratio on permeability. The results show that the permeability decreases with an increase in the power-law exponent, roughness, damage degree, bifurcation layer number, and length ratio when the diameter ratio is relatively small; on the contrary, with an increase in the diameter ratio and the power-law exponent, the permeability will increase with an increase in the bifurcation layer number; the permeability will decrease with an increase in the bifurcation layer number when the diameter ratio is large and the power-law exponent is small. The proposed model can be used to analyze the permeability of power-law fluid in a rough damaged tree-like branching network.
Hole statistics of equilibrium 2D and 3D hard-sphere crystals
Authors: Wang Haina , Huse David A. , Torquato Salvatore
Published: August 2024

The probability of finding a spherical “hole” of a given radius r contains crucial structural information about many-body systems. Such hole statistics, including the void conditional nearest-neighbor probability functions GV(r), have been well studied for hard-sphere fluids in d-dimensional Euclidean space Rd. However, little is known about these functions for hard-sphere crystals for values of r beyond the hard-sphere diameter, as large holes are extremely rare in crystal phases. To overcome these computational challenges, we introduce a biased-sampling scheme that accurately determines hole statistics for equilibrium hard spheres on ranges of r that far extend those that could be previously explored. We discover that GV(r) in crystal and hexatic states exhibits oscillations whose amplitudes increase rapidly with the packing fraction, which stands in contrast to GV(r) that monotonically increases with r for fluid states. The oscillations in GV(r) for 2D crystals are strongly correlated with the local orientational order metric in the vicinity of the holes, and variations in GV(r) for 3D states indicate a transition between tetrahedral and octahedral holes, demonstrating the power of GV(r) as a probe of local coordination geometry. To further study the statistics of interparticle spacing in hard-sphere systems, we compute the local packing fraction distribution f(ϕl) of Delaunay cells and find that, for d ≤ 3, the excess kurtosis of f(ϕl) switches sign at a certain transitional global packing fraction. Our accurate methods to access hole statistics in hard-sphere crystals at the challenging intermediate length scales reported here can be applied to understand the important problem of solvation and hydrophobicity in water at such length scales.
Impact of fire return interval on pyrogenic carbon stocks in a tropical savanna, North Queensland, Australia
Authors: Haig Jordahna , Sanderman Jonathan , Zwart Costijn , Smith Colleen , Bird Michael I.
Published: August 2024

Background Indigenous fire management in northern Australian savannas (beginning at least 11,000 years ago) involved frequent, small, cool, early dry season fires. This fire regime changed after European arrival in the late 1700s to unmanaged fires that burn larger areas, late in the dry season, detrimental to carbon stocks and biodiversity. Aims Test the hypothesis that significant sequestration of pyrogenic carbon in soil accompanies the reimposition of an Indigenous fire regime. Methods Savanna soils under the same vegetation, but with the number of fires varying from 0 to 13 (irrespective of the season) between 2000 and 2022 were sampled. Organic and pyrogenic carbon stocks as well as carbon isotope composition of the 0–5 cm soil layer were determined along sample transects with varying fire return intervals. Key results An average increase of 0.25 MgC ha−1 was observed in soil pyrogenic carbon stocks in transects with ≥5 fires, compared to transects with 0–4 fires, with a small increase in soil organic carbon stocks that was not significant. Conclusions A return to more frequent fires early in the dry season has the potential to sequester significant pyrogenic carbon in northern Australian savanna soils on decadal timescales.
Disorder-to-order active site capping regulates the rate-limiting step of the inositol pathway
Authors: Träger Toni K. , Kyrilis Fotis L. , Hamdi Farzad , Tüting Christian , Alfes Marie , Hofmann Tommy , Schmidt Carla , Kastritis Panagiotis L.
Published: August 2024

Myo-inositol-1-phosphate synthase (MIPS) catalyzes the NAD
+
-dependent isomerization of glucose-6-phosphate (G6P) into inositol-1-phosphate (IMP), controlling the rate-limiting step of the inositol pathway. Previous structural studies focused on the detailed molecular mechanism, neglecting large-scale conformational changes that drive the function of this 240 kDa homotetrameric complex. In this study, we identified the active, endogenous MIPS in cell extracts from the thermophilic fungus
Thermochaetoides thermophila
. By resolving the native structure at 2.48 Å (FSC = 0.143), we revealed a fully populated active site. Utilizing 3D variability analysis, we uncovered conformational states of MIPS, enabling us to directly visualize an order-to-disorder transition at its catalytic center. An acyclic intermediate of G6P occupied the active site in two out of the three conformational states, indicating a catalytic mechanism where electrostatic stabilization of high-energy intermediates plays a crucial role. Examination of all isomerases with known structures revealed similar fluctuations in secondary structure within their active sites. Based on these findings, we established a conformational selection model that governs substrate binding and eventually inositol availability. In particular, the ground state of MIPS demonstrates structural configurations regardless of substrate binding, a pattern observed across various isomerases. These findings contribute to the understanding of MIPS structure-based function, serving as a template for future studies targeting regulation and potential therapeutic applications.
Liquid-immersion inclined-rotated exposure system for fabricating three-dimensional microstructures with large inclination angles
Authors: Kagawa Gakuto , Takahashi Hidetoshi
Published: August 2024

This study utilized liquid-immersion inclined-rotated ultraviolet lithography to fabricate three-dimensional (3D) microstructures. The maximum achievable inclination angles obtained through conventional inclined-rotated exposure (IRE) methods were limited by the significant refractive index differences in material. We proposed an IRE with liquid-immersion and adjustable mirrors, which enabled greater inclination angles with improved adjustability. Using liquid as a medium helped minimize the refractive index disparities between materials. We fabricated polydimethylsiloxane molds for micro suction cup (MSC) array sheets to evaluate the performance of the developed liquid-immersion IRE. The resulting MSC array sheets (10 mm2) with a suction cup diameter of 500 μm, achieved inclination angles up to 51°, approximately double those obtained with the conventional IRE method. In addition, the suction force of the fabricated MSC arrays were evaluated by pulling along the vertical, horizontal, and edge directions under wet conditions. The maximum measured suction force was 0.15 N, confirming the effectiveness of the proposed liquid-immersion IRE in fabricating 3D microstructures, as demonstrated by the fabricated MSC array sheets.
Rainbow trapping and concentration of surface waves on broad waveguide
Authors: Chen Yuyang , Guo Zhaoyang , Liu Yijie , Li Jiahao , Yu Zhiwei
Published: August 2024

In recent years, topological insulators have been widely designed to manipulate various types of classical waves. The topological edge states characterized by defect and backscattering immunity show great application potential in energy harvesting. This work reports a spin-locked topological surface wave channel, which consists of concrete-filled steel tubes (CFST) placed on foundation soil. Here, the distance between the lattice and the center of the CFST controls the hopping strength between adjacent atoms, determining the topological phase transition. Introducing the surface wave crystal with Dirac cones in the interface, then the robust broad waveguide modes of phononic heterostructure are explored. Notably, incorporating the rainbow effect allows for precise regulation and reliable concentration within the broad waveguide. The proposed broad waveguide surpasses traditional waveguides by simultaneously focusing and segregating energy, enabling applications in low-frequency energy harvesting, sensing, and logic gates. Our work will provide an efficient recovery platform for daily vibration energy, especially for vehicle loads.
Low-lying excited states in 62Ge investigated by multinucleon knock-out reaction
Authors: Elekes Z , Panin V , Rodríguez T R , Sieja K , Ahn D S , Al-Adili A , Baba H , Stefanescu A I , Cook K J , Dósa Cs , Fukuda N , Gao J , Gibelin J , Hahn K I , Halász Z , Huang S W , Isobe T , Juhász M M , Kim D , Kobayashi T , Kondo Y , Korkulu Z , Kurihara A , Kuti I , Miki H , Miki K , Motobayashi T , Otsu H , Saastamoinen A , Sasano M , Sato H , Shadhin N H , Shimada T , Shimizu Y , Stefanescu I C , Stuhl L , Suzuki H , Takeda H , Togano Y , Tomai T , Trache L , Tudor D , Uesaka T , Utsuki Y , Wang H , Yasuda A , Yoneda K , Yoshitome Y
Published: August 2024

The low-energy states of the proton-rich nucleus 62Ge were studied by the multinucleon knock-out reaction 67Se(12C,X)62Ge using a 12C target. The analysis of the Doppler-corrected singles spectrum of the γ rays showed two transitions at 744(20) keV and 948(17) keV, which were found to be in coincidence with each other, forming a cascade and establishing two states at 948(17) keV and 1692(26) keV. The 744 keV transition was detected for the first time, and based on a comparison of the experimental data to shell-model and symmetry-conserving-configuration-mixing-model calculations, it connects the second and first 2+ levels. The beyond-mean-field model suggests that these states belong to two different bands with triaxial features and similar deformation.
Micromagnetic analysis of magnetic vortex dynamics for reservoir computing
Authors: Feng Ruoyan , Mohan John Rex , Yamanaka Chisato , Hasunaka Yosuke , Mathew Arun Jacob , Fukuma Yasuhiro
Published: August 2024

Reservoir computing (RC) has generated significant interest for its ability to reduce computational costs compared to traditional neural networks. The performance of the RC element is quantified by its memory capacity (MC) and prediction capability. In this study, we utilize micromagnetic simulations to investigate a magnetic vortex based on a permalloy ferromagnetic layer and its dynamics in RC. The nonlinear dynamics of the vortex core (VC), driven by continuous oscillating magnetic fields and binary digit data as spin-polarized current pulses, are analyzed. The highest MC observed is 4.1, corresponding to the nonlinear VC dynamics. Additionally, the prediction capability is evaluated using the Nonlinear Auto-Regressive Moving Average 2 task, demonstrating a normalized mean squared error of 0.0241 highlighting the time-series data prediction performance of the vortex as a reservoir.
A novel exponential unsaturated bistable stochastic resonance-boosted incipient fault identification in rotating machineries
Authors: Liu Jian , Tang Can , Hu Bing , Guo Jiaqi , Qiao Zijian , Liao Zhiqiang
Published: August 2024

Stochastic resonance (SR) for weak fault detection stands as a significant constructive methodology leveraging noise in nonlinear information systems processing. In virtue of the SR technique in conjunction with coupled non-saturated nonlinear systems, an exponential unsaturated bistable stochastic resonance (EUBSR) model is developed to enhance output levels. By integrating the exponential monostable stochastic resonance system (ESR) and the unsaturated bistable stochastic resonance (UBSR) system through coupling coefficients, this model offers a broader spectrum of resonance characteristics. The performance of the EUBSR is evaluated based on the relevant indicators signal-to-noise ratio (SNR) and residence time distribution ratio. These indicators are treated as multi-objective functions, with the coati optimization algorithm employed to optimize both the parameters and coupling coefficients of the EUBSR model simultaneously. Moreover, the paper takes into account the interdependence of nonlinear systems and their interactions by considering both cascade and parallel models of the ESR and UBSR systems. Fault diagnosis is carried out on simulation signals and bearings to validate the effectiveness of the proposed EUBSR model. The results demonstrate that the EUBSR model surpasses not only its individual component models but also cascade and parallel models.
SAHA potentiates the activity of repurposed drug promethazine loaded PLGA nanoparticles in triple-negative breast cancer cells
Authors: Choudhury Konika , Sen Plaboni , Ghosh Siddhartha Sankar
Published: August 2024

Triple-negative breast cancer (TNBC) is considered the most aggressive form of breast cancer owing to the negative expression of targetable bioreceptors. Epithelial to mesenchymal transition (EMT) associated with metastatic abilities is its critical feature. As an attempt to target TNBC, nanotechnology was utilised to augment the effects of drug repurposing. Concerning that, a combination therapeutic module was structured with one of the aspects being a repurposed antihistamine, promethazine hydrochloride loaded PLGA nanoparticles. The as-synthesized nanoparticles were 217 nm in size and fluoresced at 522 nm, rendering them suitable for theranostic applications too. The second feature of the module was a common histone deacetylase inhibitor, suberoylanilide hydroxamic acid (SAHA), used as a form of pre-treatment. Experimental studies demonstrated efficient cellular internalisation and significant innate anti-proliferative potential. The use of SAHA sensitised the cells to the drug loaded nanoparticle treatment. Mechanistic studies showed increase in ROS generation, mitochondrial dysfunction followed by apoptosis. Investigations into protein expression also revealed reduction of mesenchymal proteins like vimentin by 1.90 fold; while increase in epithelial marker like E-Cadherin by 1.42 fold, thus indicating an altered EMT dynamics. Further findings also provided better insight into the benefits of SAHA potentiated targeting of tumor spheroids that mimic solid tumors of TNBC. Thus, this study paves the avenue to a more rational translational validation of combining nanotherapeutics with drug repurposing.
Axisymmetric fluid streamer model in the AMReX library
Authors: Simonović I , Bošnjaković D , Teunissen J , Dujko S
Published: August 2024

We have implemented an axisymmetric fluid model of streamers in the AMReX open-source library. Our implementation is based on the first-order fluid model with a local field approximation. Photoionization is implemented by employing the Zhelenznyak’s model using the Helmholtz approach. We have verified our code in standard conditions by comparing our results for positive streamers in air with the existing benchmarks from the literature. To verify the performance of our code in strongly attaching gases, we compare the properties of negative streamers with those obtained from the Afivo-streamer open-source code. Calculations have been performed in mixtures of carbon dioxide and perfluoro-nitrile with a background number density of electrons and positive ions of 1013 m−3. We found an excellent agreement between the two sets of results, which indicates the numerical integrity of our code.
Design and motion analysis of soft robotic arm with pneumatic-network structure
Authors: Zhu Yinlong , Wang Tian , Gong Weizhuang , Feng Kai , Wang Xu , Xi Shuang
Published: August 2024

Soft robotic arms have been widely explored in recent years because of their excellent flexibility and infinite degrees of freedom which distinguishes them form traditional rigid robots. This paper focuses on the design, fabrication and kinematic analysis of a new modular soft robotic arm featuring multiple segments, each one with three degrees of freedom. In contrast to most research, this paper utilizes soft pneu-net structure instead of fiber-reinforced structure, thereby preventing large local strains due to membrane pressurized against a fiber reinforcement. We employed finite element method and orthogonal experiment were to ascertain the optimal structural parameters. Furthermore, we present the kinematic model of the soft arm by the parameterization of the Denavit–Hartenberg convention under the basis of constant curvature assumption. Finally, the experimental evaluation of the soft robotic arm including bending angle, elongation, deflection and flexibility test were carried out. The experimental data, particularly concerning the bending angle and spatial position of both single modular and two-modular soft arm agree well with the finite element method simulation. Additionally, we performed both grasping and obstacle-avoidance grasping tests for dual modular soft robotic. The results demonstrate that the soft robotic arm exhibits superior performance and highlights its potential for various applications.
The precursor of the critical transitions in majority vote model with the noise feedback from the vote layer
Authors: Liu Wei , Wang Jincheng , Wang Fangfang , Qi Kai , Di Zengru
Published: August 2024

In this paper, we investigate phase transitions in the majority-vote model coupled with noise layers of different structures. We examine the square lattice and random-regular networks, as well as their combinations, for both vote layers and noise layers. Our findings reveal the presence of independent third-order transitions in all cases and dependent third-order transitions when critical transitions occur. This suggests that dependent third-order transitions may serve as precursors to critical transitions in non-equilibrium systems. Furthermore, we observe that when the structure of vote layers is decentralized, the coupling between the vote layer and the noise layer leads to the absence of critical phenomena.
Exploring antecedents to climate migration: sense of place, fear and worry, and experience
Authors: Berlin Rubin Nina , Garfin Dana Rose , Wong-Parodi Gabrielle
Published: August 2024

The bond between people and the place they live has significant implications for their migration decisions. However, few studies have examined how this relationship endures in the face of experience with climate-related hazards and associated emotions, and whether detachment from place may be related to future migration. Here we address this gap using cross-sectional survey data from a representative probability-based sample of 1479 residents of Texas and Florida—areas frequently affected by coastal hazards—to investigate the interplay between place attachment, place detachment, negative hazard experiences, hazard-related fear and worry, and prospective migration. We found that place attachment and detachment were inversely associated with one another, and that hazard-related fear and worry was associated with higher place detachment. Results indicated that place detachment and hazard-related fear and worry were positively associated with prospective migration, while place attachment was negatively associated with prospective migration. The absence of place attachment and presence of detachment may lower psychological barriers to relocation in the face of climate change. Negative hazard experiences were not associated with place attachment, place detachment, or prospective migration. However, our post-hoc analyses found an indirect association between negative hazard experiences and prospective migration, mediated by hazard-related fear and worry. This suggests that psychological correlates of climate hazards, possibly arising from experiencing them, may inform people’s sense of place and future migration decisions. Our findings highlight the salience of relationships with place in migration decisions and stress the importance of explicitly examining negative sentiments towards place in migration studies. These insights can both improve climate migration models and help tailor policies and programs aimed at supporting detached, fearful, and worried individuals in anticipation of future climate-related hazards.
Learning based model for predicting mechanical properties and sustainable filler band for NBR composites using lignin and carbon black
Authors: Kachirayil Antony J , Nambiathodi Vaishak , Thomas Bony , Raveendran Radhika , Varghese Siby , Mukundan Manoj Kumar , Rajesh Raghunathan
Published: August 2024

Experimental determination of mechanical properties of rubber composites, such as tensile strength and hardness, involves complex multistage preparation procedures that are laborious and expensive. In this study, a hybrid filler of carbon black (CB) along with a sustainable filler of lignin is added for reinforcement in the nitrile butadiene rubber (NBR) matrix, with the total filler content varying from 10 parts per hundred rubber (phr) to 80 phr. This work aims to develop a data-driven predictive model for the mechanical properties of rubber composites. An artificial neural network (ANN) model using multilayer feed-forward back-propagation has been created to forecast the tensile strength (Ts) and hardness (Hd) of rubber composites. The model predicts the uniaxial tensile response and hardness using input parameters that include total filler and lignin loading levels. The effectiveness of the suggested prediction method was demonstrated by statistical analysis using confidence intervals, showing a prediction error between 5.47% and 3.23% for the Ts and between 3.03% and 1.85% for Hd at 95% confidence intervals. A sustainable green band could be defined in the developed model, which is handy for designers to replace CB with lignin in various NBR based products, such as hoses, seals, etc., without compromising on tensile strength and hardness.
Coupled model intercomparison project phase 6 (CMIP6) high resolution model intercomparison project (HighResMIP) bias in extreme rainfall drives underestimation of amazonian precipitation
Authors: Negron-Juarez Robinson , Wehner Michael , Silva Dias Maria Assunção F , Ullrich Paul , Chambers Jeffrey Q , Riley William J
Published: August 2024

Extreme rainfall events drive the amount and spatial distribution of rainfall in the Amazon and are a key driver of forest dynamics across the basin. This study investigates how the 3-hourly predictions in the High Resolution Model Intercomparison Project (HighResMIP, a component of the recent Coupled Model Intercomparison Project, CMIP6) represent extreme rainfall events at annual, seasonal, and sub-daily time scales. TRMM 3B42 (Tropical Rainfall Measuring Mission) 3 h data were used as observations. Our results showed that eleven out of seventeen HighResMIP models showed the observed association between rainfall and number of extreme events at the annual and seasonal scales. Two models captured the spatial pattern of number of extreme events at the seasonal and annual scales better (higher correlation) than the other models. None of the models captured the sub-daily timing of extreme rainfall, though some reproduced daily totals. Our results suggest that higher model resolution is a crucial factor for capturing extreme rainfall events in the Amazon, but it might not be the sole factor. Improving the representation of Amazon extreme rainfall events in HighResMIP models can help reduce model rainfall biases and uncertainties and enable more reliable assessments of the water cycle and forest dynamics in the Amazon.
Hybrid energy storage systems for fast-developing renewable energy plants
Authors: Zhao Junjie , Wang Fan , Ruan Qidong , Wu Yong , Zhang Bing , Lu Yingying
Published: August 2024

To achieve zero carbon emissions, renewable energy sources are highly promising alternatives to fossil fuels. However, the intermittency of renewable energy sources hinders the balancing of power grid loads. Because energy storage systems (ESSs) play a critical role in boosting the efficiency of renewable energy sources and economizing energy generation, different ESSs and their applications in various environments must be comprehensively investigated. With sustained growth in the global demand for ESSs, reliance on a single technology may not comprehensively fulfill the anticipated requirements for the ESS cycling life, efficiency, cost, and energy/power densities. Hence, hybrid ESSs (HESSs), combining two/multiple ESSs, offer a promising solution to overcome the constraints of a single ESS and optimize energy management and utilization. Therefore, this review extensively and comprehensively describes ESSs, including their classifications, mechanisms, strengths, and weaknesses, and introduces several typical HESS energy management strategies and application domains.
Compact narrow slot antenna with stable radiation pattern and wide bandwidth
Authors: Ashvanth Balu
Published: August 2024

One of the most crucial parameters for any antenna is bandwidth. Over the whole extended bandwidth, the antenna achieves a high gain of 5dBi and a steady bidirectional radiation pattern. A novel design concept for increasing bandwidth and maintaining a consistent radiation pattern has been proposed for the radiated fields of a slot antenna. First, the radiated fields of the standard slot antenna are examined theoretically using characteristic modes (CMs). Its three CMs vibrate at 2.45, 4.78, and 7.17 GHz, respectively, according to the results. CM1 and CM3 both continue to emit radiation in both directions, but CM2 generates a radiation null in the broadside direction. After that, the linear slot is appropriately folded to change CM2’s non-bidirectional pattern into a bidirectional one, allowing for the broad bandwidth use of the neighbouring CM1 and CM2. The narrow slot is then used to create the stepped scheme, which reallocates these dual modes in close proximity to one another. By using these designs, the antenna’s radiation pattern consistency and small size of 0.022λo can be preserved, but its impedance bandwidth can be significantly expanded. After that, the proposed antenna is constructed and assessed. Measurements show that the antenna has a broad bandwidth (|S11|<−10 dB) of around 35.14%, covering the frequency range of 3.3 to 4.6 GHz.
Single gate heterostructure dopingless TFET: a comprehensive sensitivity investigation with exposure to various chemical analytes
Authors: Panda Shwetapadma , Dash Sidhartha
Published: August 2024

This study proposes a new chemical sensor designed using a single gate heterostructure dopingless tunnel field effect transistor (SG-HS-DLT). Combining Si0.6Ge0.4 in the source and HfO2 as the gate dielectric improves the sensor’s drain current sensitivity. Many chemical analytes, including hexane (C6H14), methanol (CH3OH), isopropanol (Iso-C3H7OH), dichloromethane (CH2Cl2), and chloroform (CHCl3) have been considered during the investigation. The conducting polymer is used as the gate metal due to its compatibility with the electronic chemical sensor. Modifying the gate work function with exposure to chemical substances is employed to determine the sensitivity of the reported chemical sensor. The electrical performance of the sensor is examined using transfer characteristics, switching ratio, average SS, BTBT rate, threshold voltage, electron concentration, energy band, and potential. Correspondingly, the sensitivity investigation comprises drain current sensitivity (SDrain), current ratio sensitivity (SR), average SS sensitivity (SAvgSS), and threshold voltage sensitivity (SVT). Further, the sensitivity analysis is extended for various temperatures and mole fractions (x). The SG-HS-DLT chemical sensor displays a higher value of SDrain of 3.64 × 105, SAvg.SS of 0.69444 for CHCl3 at room temperature. This article extensively uses the Silvaco TCAD simulation software to investigate the proposed chemical sensor.