bluuebunny/crossref_metadata_2025_split huggingface dataset:
An investigation of the electrical dynamics in electroactive polymer transducers with resistive electrodes
Authors: Vignotto Davide , Cherubini Antonello , Sîrbu Ion-Dan , Fontana Marco , Moretti Giacomo 
Published: July 2024

Abstract
To pursue a variable-capacitance working principle, transducers based on soft electroactive polymers (EAPs) need deformable electrodes that match the compliance and stretchability of the EAP polymeric substrates. A variety of manufacturing procedures are available to create conductive materials that can achieve this, including solutions that can provide remarkably low resistivity. However, the simplest and most feasible options often involve the use of particle-filled (e.g. carbon-filled) polymer composites, which, while easy to produce, tend to exhibit relatively high resistivity. This high level of resistivity, combined with the inherent capacitance of EAP transducers, introduces dynamic effects in the devices electrical activation, which may affect performance. This paper investigates the impact of electrode resistivity on the electrical dynamics of EAP devices, combining continuum models and experimental validations. We use a continuum generalisation of known resistive-capacitive (RC) transmission line models to accurately predict voltage gradients on the surfaces of electrostatic transducers subject to rapidly varying voltages. We then present an experimental validation by measuring the spatial voltage distributions over carbon-based polymeric electrodes of dielectric elastomer (DE) transducers, and find a good agreement with our model predictions. We use our validated model to provide general estimates of the typical charging time and limit working frequency ranges of DE devices as a function of their dimensional scale and electrode sheet resistance. Our model provides useful indications for designing compliant electrodes in EAP transducers given target performance, or to understand the working limits of devices with given geometry and dielectric-electrode properties.
Development of a pump-jet piezoelectric swimmer with acoustic radiation actuation
Authors: Zheng Xiuli , Liu Junming , Wang Le , Chen Si , Liu Zhiling 
Published: July 2024

Abstract
The acoustofluidic actuation produced by piezoelectric transducer is capable of propelling micro underwater robots forward, yet the motion pattern is relatively simplistic. To solve this problem, a pump-jet swimmer with a combination of the underwater acoustic radiation effect is proposed in this work. The absorption and discharge of internal piezoelectric pump provide the linear forward power, and turning is achieved under the acoustic propulsive force of the external dual piezoelectric actuators. The working mode and optimal driving frequency of the piezoelectric actuators are determined through finite element simulation and mechanical vibration characteristic tests. And the key dimensional parameters of the piezoelectric pump are optimized in the light of the output flow measurements. Finally, a prototype with the size of Ф3.1 cm × 12 cm is fabricated for underwater driving performance experiments, which demonstrated well functions in straight swimming, turning, and loading. The swimmer with 20 g of additional load achieves a maximum speed of 105 mm s−1at the voltage of 180 Vp-p, it also completes the obstacle avoidance in water along a certain path. The rationality of this conceived actuation mechanism is preliminarily verified, which shows a potential for fixed-point transportation in the complex underwater situations.
Thermally-assisted magnetization of magnetic composites for enhanced micro actuator performance: a low-cost approach using permanent magnets
Authors: Wu Pucheng , Wang Langkun , He Hu 
Published: July 2024

Abstract
A micro actuator based on magnetic composite materials can control its deformation and movement through varying magnetic fields, showcasing significant applications in fields such as soft robotics and biomedicine. However, existing magnetic composite materials still require complex magnetization processes involving sophisticated equipment and demanding external magnetic fields. This paper proposed a low-cost, thermally-assisted magnetization process based on permanent magnets. It was observed that the maximum magnetic induction intensity on the surface of magnetic composites is linearly correlated with the heating temperature. Additionally, magnetically treated materials at elevated temperatures can achieve traditional high-field magnetization effects at lower field strengths. Specifically, we synthesized a magnetic composite with 50%wt NdFeB@PDMS and investigated the conditions of the thermally-assisted magnetization process based on permanent magnets, along with mechanical and magnetic performance characterization methods. Experimental results indicate that below 200 °C, the tensile strength and elastic modulus of the base material increase with rising temperatures, demonstrating a trend of high-temperature hardening. However, when the temperature exceeds 200 °C, the elevated temperature leads to the decomposition of the base material, resulting in a rapid decrease in the tensile strength and elastic modulus of the magnetic composite. Furthermore, high temperatures can disrupt the magnetic domains of the magnetic material, reducing its coercive force and making it more susceptible to external magnetic fields and heat, thereby compromising the stability of the magnetic material. These findings provide new insights into the development of more stable and controllable magnetic composite materials.
Influence of GO content on the optical, magnetic and dielectric properties of the BaFe12O19/GO nanocomposites
Authors: Mehrabani Mona , Ghazi M E , Izadifard Morteza 
Published: July 2024

Abstract
In this research, BaFe12O19/GO (GO:10, 20, 40, and 50 wt%) nanocomposites were synthesized by sol–gel auto combustion method and their structural, optical, magnetic and dielectric properties were investigated. The x-ray diffraction results for all nanocomposites validate the formation of a hexagonal phase of Ba hexaferrite. The crystallite size decreased with incorporation of graphene oxide (GO) in the hexaferrite phase and making the nanocomposites. In the FESEM analysis, a change in the surface morphology was observed with an increase in the percentage of GO for samples BFO-40GO and BFO-50GO. The band gap energy of the nanocomposites decreased with increasing the amount of the graphene oxide. Measurements of the magnetic hysteresis loop for all nanocomposites were conducted using a vibrating sample magnetometer at room temperature. By increasing the percentage of GO, a decrease in the saturation magnetization was observed for the samples. A decrease in dielectric constant and loss function were also detected at low frequencies when the GO continent goes up. The nanocomposite sample of BFO-40GO exhibited the highest observed value for real part of the Modulus.
Deep learning of plausible bandgaps in dispersion curves of phononic crystals
Authors: Farajollahi Amirhossein , Seyyed Fakhrabadi Mir Masoud 
Published: July 2024

Abstract
Phononic crystals represent an interesting class of metamaterials that can be utilized to regulate or manipulate vibration, sound propagation, and thermal transport. Their useful features mainly arise from the bandgaps in their dispersion curves, preventing the passage of waves within specific frequency ranges. However, it is often costly and time-consuming to obtain the dispersion curves, and the reverse engineering of phononic crystals to have pre-defined bandgaps possesses even greater challenges. In this research, we address this issue by employing a deep artificial neural network to predict the bandgap ratio and the characteristics of plausible bandgaps, focusing on the localized resonance in columnar phononic crystals. We utilized two geometric parameters, i. e. the ratio of diameter and height of the cylindrical resonators relative to the lattice constant, achieving a determination coefficient of 0.9993 for predicting the characteristics of the bandgaps and 0.9827 for predicting the bandgap ratio. To verify the model and better understand its behavior, we introduce Shapley values. These values provide a comprehensive insight into how each geometric parameter influences the predicted bandgap ratios.
Generalised conditions for rapid-turn inflation
Authors: Wolters Raúl , Iarygina Oksana , Achúcarro Ana 
Published: July 2024

AbstractRapid-turn slow-roll inflationary trajectories have been shown to be an attractor in two-field models, provided the turn rate is near constant and larger than the slow-roll parameters. These trajectories can produce primordial spectra consistent with current observations on CMB scales. We present the generalized consistency condition for sustained rapid-turn inflationary trajectory with two fields, arbitrary field-space metric and potential valid for any value of the turn rate. This has to be supplemented by a second condition to ensure slow roll evolution. Both conditions together constitute a tool to identify inflationary trajectories with arbitrary values of the turning rate without having to solve the equations of motion. We present a Python package for the numerical identification of regions in field-space and parameter space that allow for rapid-turn trajectories.
A diffused background from axion-like particles in the microwave sky
Authors: Mehta Harsh , Mukherjee Suvodip 
Published: July 2024

AbstractThe nature of dark matter is an unsolved cosmological problem and axions are one of the weakly interacting cold dark matter candidates. Axions or ALPs (Axion-like particles) are pseudo-scalar bosons predicted by beyond-standard model theories. The weak coupling of ALPs with photons leads to the conversion of CMB photons to ALPs in the presence of a transverse magnetic field. If they have the same mass as the effective mass of a photon in a plasma, the resonant conversion would cause a polarized spectral distortion leading to temperature fluctuations with the distortion spectrum. The probability of resonant conversion depends on the properties of the cluster such as the magnetic field, electron density, and its redshift. We show that this kind of conversion can happen in numerous unresolved galaxy clusters up to high redshifts, which will lead to a diffused polarised anisotropy signal in the microwave sky. The spectrum of the signal and its shape in the angular scale will be different from the lensed CMB polarization signal. This new polarised distortion spectrum will be correlated with the distribution of clusters in the universe and hence, with the large-scale structure. The spectrum can then be probed using its spectral and spatial variation with respect to the CMB and various foregrounds. An SNR of ~ 4.36 and ~ 93.87 are possible in the CMB-S4 145 GHz band and CMB-HD 150 GHz band respectively for a photon-ALPs coupling strength ofgaγ= 10-12GeV-1using galaxy clusters beyond redshiftz= 1. The same signal would lead to additional RMS fluctuations of ~7.5 × 10-2μK at 145 GHz. In the absence of any signal, future CMB experiments such as Simons Observatory (SO), CMB-S4, and CMB-HD can put constraints on the coupling strength better than current bounds from particle physics experiment CERN Axion Solar Telescope (CAST).
Comparing online wrist and forearm EMG-based control using a rhythm game-inspired evaluation environment
Authors: Meredith Robyn , Eddy Ethan , Bateman Scott , Scheme Erik 
Published: July 2024

Abstract

Objective. The use of electromyogram (EMG) signals recorded from the wrist is emerging as a desirable input modality for human–machine interaction (HMI). Although forearm-based EMG has been used for decades in prosthetics, there has been comparatively little prior work evaluating the performance of wrist-based control, especially in online, user-in-the-loop studies. Furthermore, despite different motivating use cases for wrist-based control, research has mostly adopted legacy prosthesis control evaluation frameworks. Approach. Gaining inspiration from rhythm games and the Schmidt’s law speed-accuracy tradeoff, this work proposes a new temporally constrained evaluation environment with a linearly increasing difficulty to compare the online usability of wrist and forearm EMG. Compared to the more commonly used Fitts’ Law-style testing, the proposed environment may offer different insights for emerging use cases of EMG as it decouples the machine learning algorithm’s performance from proportional control, is easily generalizable to different gesture sets, and enables the extraction of a wide set of usability metrics that describe a users ability to successfully accomplish a task at a certain time with different levels of induced stress. Main results. The results suggest that wrist EMG-based control is comparable to that of forearm EMG when using traditional prosthesis control gestures and can even be better when using fine finger gestures. Additionally, the results suggest that as the difficulty of the environment increased, the online metrics and their correlation to the offline metrics decreased, highlighting the importance of evaluating myoelectric control in real-time evaluations over a range of difficulties. Significance. This work provides valuable insights into the future design and evaluation of myoelectric control systems for emerging HMI applications.
Reduced graphene oxide-modified electrodes via fused deposition modeling 3D printing for hydrogen peroxide sensor
Authors: Dou Yan , Dai Rui , Sun Haofan , Bi Kun , Zhao Xin , Nian Qiong 
Published: July 2024

Abstract
Fused deposition modeling 3D printing provides a cost-effective and streamlined method for producing electrochemical sensors, overcoming the challenges associated with material selection, complex fabrication processes, and reproducibility issues. This study introduces an innovative approach utilizing a dual-printer setup to simplify the manufacturing of sensor electrodes. A critical enhancement in this process is the surface modification with reduced graphene oxide (rGO), which not only improves the electrochemical characteristics but also induces a wrinkled structure on the 3D printed surface. These wrinkles significantly increase the surface area, directly boosting the electrode’s electrochemical performance. Comprehensive characterization of the electrode surfaces, both before and after rGO modification, demonstrates a substantial increase in sensitivity, with a fortyfold improvement observed in hydrogen peroxide (H2O2) amperometric measurements. This breakthrough paves the way for advanced applications in 3D printed electrochemical sensors.
Perspectives on 2D materials for hybrid and beyond-Si image sensor applications
Authors: Wan Haochuan , Xu Zhihao , Zhang Yiheng , Zhao Junyi , Wang Chuan 
Published: July 2024

Abstract
The complementary metal–oxide–semiconductor (CMOS) image sensor has become essential and ubiquitous in our daily lives as it is present in almost every pocket. As demand for compact, multifunction, and high-efficiency Internet of Things applications continues to rise, novel configuration designs and manufacturing methods, such as neural network integration and 3D stacking have been implemented to enhance the CMOS image sensor’s (CIS) performance. However, the progress of image sensors based on silicon CMOS technology would eventually be limited by the intrinsic optical, electrical, and mechanical properties of silicon material. This has led to the exploration of two-dimensional materials (2DMs) and the emergence of 2DMs as promising candidates for the next generation of optoelectronic devices. In this article, we discuss the current advancements and challenges associated with silicon CISs and the potential benefits of incorporating 2DMs in the image sensor. We highlight three critical opportunities for 2DMs, including Si CMOS/2DMs hybrid structure and direct growth techniques of 2DMs on Si for back-end-of-line integration, 2DMs-based neuromorphic photodetectors (PDs) and optical neural networks for in-image-sensor-processing, and curved image sensor based on 2DMs PDs for bionic detection. With the growing maturity of 2DM technologies, we anticipate that the device scaling and the increase of integration density of 2DM electronics in the image sensor will continue, leading to the development of highly efficient, compact, intelligent, and versatile 2DM image sensors in the near future.
Study on the properties and mechanisms of the glazed hollow bead thermal insulation mortar
Authors: Zhan Wangxing , Li Xiaohua , Zeng Zhi , Yang Hao , Feng Zhao , Huang Fan , Su Liubin 
Published: July 2024

Abstract
With increasing concerns for energy conservation and environmental protection, research on glazed hollow bead thermal insulation mortar is of utmost importance. This type of mortar offers superior thermal insulation, leading to reduced energy consumption and emissions, in line with the current green building trends. This article aims to investigate the impact of varying component proportions on the parameters of thermal insulation mortar through an orthogonal experiment with four factors and three levels: glazed hollow bead, sepiolite, air-entraining agent, and cellulose ether. Additionally, a single-factor experiment is conducted to analyze the influence degree of water-solid ratio and these four factors. The experimental results are then verified through SEM (Scanning Electron Microscope) observation. The research findings indicate that glazed hollow beads have the most significant impact on thermal conductivity and compressive strength, while the air-entraining agent exerts the greatest influence on flexural strength. Specifically, when the content of glazed hollow bead is 2%, sepiolite 1%, air-entraining agent 0.6%, and cellulose ether 0.6%, the thermal conductivity can reach a minimum value of 0.0533W/(m·K). On the other hand, when the content of glazed hollow bead is 1%, sepiolite 2%, air-entraining agent 0.4%, and cellulose ether 0.6%, the compressive strength can achieve a maximum value of 2.4 MPa. These findings provide a solid foundation for further exploration into improving the performance of thermal insulation mortar.
Revealing the journey of molecules and particles in heterogeneous, porous materials for cigarette filters
Authors: Lei Sheng , Zhang Ling , Wang Kai , Liu Chunbo , Li Xianyi , Tang Zhongqiu , Jiang Lingxiang 
Published: July 2024

Abstract
Molecular dynamics and mass transportation in porous structures provide a basis for us to understand catalysis, energy storage and generation, and biological processes in porous confinements. While conventional methods extract macroscopic information in an ensemble-averaged manner, we intend to follow the journey of individual particles and molecules in porous structures relevant to cigarette filters by tracking the single-object dynamics in real space and real time. Nanoparticles of various sizes are embedded in fibrous frameworks of agarose where small particles (50 nm) can explore pores and their connections, locally mapping out the porous structure, middle-sized particles (100 nm) are trapped in single pores to fluctuate within, and large particles (500 nm) are fully immobilized by surrounding fibers. This model system is relevant to the retention and filtration of tar particles or other kinds of particulate matters by fibrous cellulose frequently used in cigarette filters. A molecular tracer is loaded to zeolite-based porous structures, where the majority are fixated in space by adsorption or micropore trapping, exhibiting localized trajectories within a 10-nm radius, and the minority are mobile to scout macropores. This molecular system may elucidate on how aromatic molecules like PAHs are adsorbed and transported in a matrix of mixed micro-, meso-, and macropores.
On the vanishing of Green’s function, desingularization and Carleman’s method
Authors: Gibara R. , Kinzebulatov D. 
Published: July 2024

The subject of the present paper is the phenomenon of vanishing for the Green function of the operator

−
Δ
+
V

-\Delta + V

on

R

3

\mathbb {R}^3

at the points where the potential

V
V

has positive critical singularities. More precisely, under minimal assumptions on

V
V

(i.e., the form-boundedness), an upper bound on the order of vanishing of the Green function is obtained. As a byproduct, the existing results on the strong unique continuation for eigenfunctions of

−
Δ
+
V

-\Delta +V

in dimension

d
=
3

d=3

are improved.
The Viability of Rationalism
Authors: Laurence Stephen , Margolis Eric 
Published: July 2024

Abstract
In contemporary philosophy and cognitive science, there is a great deal of scepticism not only about the rationalism-empiricism debate but also about rationalist accounts of the origins of psychological traits in particular. This chapter explores a wide range of objections to rationalism which in different ways hold that rationalism in general is inherently flawed independently of the details of particular rationalist accounts. We argue that none of these arguments provide any grounds for rejecting rationalist accounts. Seeing how these arguments fail sheds much further light on the rationalism-empiricism debate and on what is—and isn’t—implied by rationalist accounts.
Conclusion to Part II
Authors: Laurence Stephen , Margolis Eric 
Published: July 2024

Abstract
This chapter provides a brief conclusion to Part II, which presents the bulk of our positive case for our concept nativism. This case takes the form of an argument to the best explanation that draws upon a wealth of data and theoretical argumentation. To clarify the logic of the reasoning involved, we have distinguished seven subsidiary arguments: The argument from early development (Chapters 8 and 9), the argument from animals (Chapter 10), the argument from universality (Chapter 11), the argument from initial representational access (Chapter 12), the argument from neural wiring (Chapter 13), the argument from prepared learning (Chapter 14), and the argument from cognitive and behavioural quirks (Chapter 15). These arguments should be seen as working together to form a single larger argument which we will continue to develop with other case studies and further elaboration in Parts III and IV.
The Evolution of Fodor’s Case against Concept Learning
Authors: Laurence Stephen , Margolis Eric 
Published: July 2024

Abstract
The concept nativism that we defend in this book stands in opposition to empiricist approaches to the origins of concepts, but it equally stands in opposition to Jerry Fodor’s radical concept nativism—the view that virtually all lexical concepts are innate—and his notorious claim that concept learning is impossible. In Part IV, we turn to Fodor’s views about concept acquisition, show where they go wrong, and explain how our concept nativism, in contrast with Fodor’s radical concept nativism, embraces the fact that most concepts are learned. In this chapter, we examine what Fodor has had to say about these issues in publications spanning more than thirty years and the important changes to his views over this time, culminating in his most thorough case against concept learning in his book LOT2: The Language of Thought Revisited.
Fodor’s Biological Account of Concept Acquisition—and the Importance of Cultural Learning
Authors: Laurence Stephen , Margolis Eric 
Published: July 2024

Abstract
In LOT2, Fodor provides a new account of the origins of concepts that is based on the assumption that they can’t be learned (since he argues that concept learning is impossible) but that they also aren’t innate (unlike his own earlier radical concept nativism). This takes the form of a biological theory of concept acquisition, in which their acquisition isn’t explained in psychological terms. In this chapter, we show why a biological account is unworkable and why the only viable type of account is one that fully embraces the idea that most concepts are learned. In doing so, we highlight the central role of culture and cultural learning in explaining the origins of human concepts in their enormous variety, and how, contrary to common empiricist assumptions, the centrality of culture to concept learning favours precisely the sort of concept nativism that we defend in this book.