bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase transitions, elastic and electronic properties of hydrogen storage Na2PdH4
Authors: Al S. , Kurkcu C.
Published: December 2021

Hydrogen can be absorbed by some materials at specific pressures and temperatures. This is extremely important in terms of creating carbon-free and sustainable society. In this work hydrides are good candidates to fulfill these aims. Electronic and magnetic properties of hydrides are investigated. This study considers Na2PdH4 as solid storage of hydrogen material. Hydrogen is highly soluble in palladium and can be stored in large amounts at ambient conditions. The structural evolution, electronic and elastic properties of Na2PdH4 has been investigated by means of density functional theory. The SIESTA software package is used with the generalized gradient approximation for the exchange-correlation functional and norm-conserving Troullier–Martins pseudopotentials. High-pressure computations have been carried out to reveal phase transitions. Na2PdH4 is transformed from I4/mmm tetragonal structure to Immm orthorhombic structure at 100 GPa. The electronic band structures and density of states are obtained for both phases. Mechanical stability is analyzed using the elastic constants. Moreover, several parameters such as Young’s modulus, shear modulus, and their ratios are obtained and discussed.
Superionic rubidium silver iodide gated low voltage synaptic transistor
Authors: Mukherjee Arka , Sagar Srikrishna , Parveen Sumaiya , Das Bikas C.
Published: December 2021

Nonvolatile resistive switching based memristor and memtransistor devices have emerged as a leading platform in neuromorphic computing. In this work, we have fabricated a multifunctional synaptic transistor (ST) using a conjugated polymer P3HT channel and a superionic rubidium silver iodide (RbAg4I5) thin film coated over a polyethylene oxide (PEO) layer as the gate dielectric. Large hysteresis in the transfer curve represents the memristive behavior with at least 105 current On/Off ratio. Enormously large specific capacitance induced by the electrical double layers at the interfaces of PEO/RbAg4I5 dielectric induces polaron (P3HT+) generation in the channel through bound states formation by the electrons with Ag+ ions and consequent movement of iodine (I−) counter ions toward the P3HT channel under a negative gate bias stress. This is strongly supported by the blue shift of the Raman peak from 1444.2 to 1447.9 cm−1 and the appearance of a new peak at 1464.6 cm−1. Interestingly, the proposed ST device exhibits various synaptic actions, which include an excitatory postsynaptic current, paired-pulse facilitation, and short-term potentiation to long-term potentiation after repeated rehearsal on top of standard nonvolatile data storage capability. Our ST also depicts an enhanced retention to 103 s and more than 103 discrete On- and Off-states during potentiation and depression function modulation, respectively, just by consuming a very low energy of about 2.0 pJ per synaptic event. These results are very significant to make this organic synaptic transistor as a potential candidate in terms of the desired metrics for neuromorphic computation at low cost and improved accuracy in the future.
Photodetachment of H− in non-ideal classical plasmas
Authors: Das Biswajit , Ghoshal Arijit
Published: December 2021

The effects of non-ideality of classical plasmas on the cross sections of the photodetachment of the negative ion of hydrogen (H−) have been investigated within the framework of the dipole approximation. An effective potential, deduced from a solution of Bogolyubov's hierarchy equations, has been used to model the interactions among the charged particles in the non-ideal classical plasmas. Wave functions and energies of H−(1S) and H(1s) are calculated accurately by employing extensive basis sets within the framework of Ritz's variational principle. A detailed study is made on the changes of photodetachment cross section due to the varying non-ideality of plasma in a wide range. It is found that the wavelength corresponding to the maximum value of the photodetachment cross section moves forward due to the increasing non-ideality of plasma.
Flow characteristics of elastically mounted slit cylinder at sub-critical Reynolds number
Authors: Verma Mayank , Mishra Alok , De Ashoke
Published: December 2021

The present work numerically investigates vortex-induced vibrations (VIV) of a two-dimensional circular cylinder with an axisymmetric slit at Reynolds number 500. The study examines the effects of slit shape (i.e., converging, diverging, and parallel slits), the effect of slit-area ratios, slit width, and its angle with the freestream velocity on aerodynamic forces, vibration response, and associated flow characteristics. The results demonstrate that the addition of the slit assists the VIV suppression by adding an extra amount of flow to the main flow. It results in the stabilized wake with the pressure recovery downstream of the cylinder and causes a reduction in the lift force over the cylinder. Also, there exist different shedding patterns associated with different slit shapes. A proper orthogonal decomposition of the flow field suggests that among all the three slits, the parallel slit heavily modifies the flow behind the cylinder by distributing the amount of energy to a large number of modes as compared to other slits (converging slit and diverging slit), where the most of the energy is contained in a couple of modes. Further, increasing the slit angle (for parallel slit) with respect to the freestream increases the slit effectiveness up to a specific value of slit-angle and beyond that starts to affect the VIV suppression adversely. Observations for the effect of slit width are also reported from the perspective of suppression of VIV.
Lattice Boltzmann modeling of particle dynamics in rotating coordinate system
Authors: Zhang Jiangang , Zhang Xitong , Wang Ningning , Liu Haihu , Xi Guang
Published: December 2021

Centrifugal rotation is one of the most important techniques for separating and purifying particles or cells, which enables broad applications in biomedicine and chemistry. To study the separation mechanism of the rotating flow, a lattice Boltzmann method is developed to simulate particulate flows in the rotating coordinate system, where the centrifugal and Coriolis forces are exerted not only on the fluid but also on the particles. This method is first validated by simulation of two benchmark cases, namely, the external force driven flow in the rotating coordinate system and the motion of a single particle in a rotating fluid disk. It is then used to investigate the dynamics of a single particle, two particles and a particle cluster in a rotating channel. Results show that the centrifugal force and Coriolis force drive the particle to move toward the outlet and toward the bottom wall, respectively, and decreasing particle size can reduce the hydrodynamic resistance, thus making the particle move faster. In the two-particle system, the particle-particle interaction is found to play an important role, which could cause the downstream particle to move first downward and then upward when the particle mass is small, or to exhibit a damped oscillation behavior when the particle mass is large. By simulating the motion of a particle cluster, we demonstrate the capability of the rotating channel to screen particles with different sizes or masses.
Characterization of PN junctions of doped Mott insulators
Authors: Wang Shu-tong , Zhang Yiou , Marston J. B. , Xiao Gang
Published: December 2021

A heterojunction comprising a La1.9Sr0.1CuO4 thin film on a 0.5 wt. % Nb doped SrTiO3 single-crystal substrate was fabricated using magnetron sputtering deposition and ion milling etching techniques. Rectification has been observed in the current–voltage characteristics of the heterojunctions from 30 to 300 K. The temperature evolution of the ideality factor implies the important role of barrier inhomogeneity at the junction interface. A systematic study of capacitance as a function of frequency under different bias voltages at room temperature was also carried out. The capacitance can be explained by deep-level defects in the space charge region.
Using distributions to understand neutron and x-ray production in ICF ignition capsules and other high energy density plasmas
Authors: Nilsen Joseph , Managan Robert A. , Zimmerman George B.
Published: December 2021

This paper describes how x-ray and neutron distribution functions can be useful tools to visualize the conditions measured in many types of plasma physics experiments. In particular, we model a standard inertial confinement fusion ignition capsule that consists of a Si doped plastic ablator surrounding a layer of deuterium–tritium (DT) ice as the yield varies from 18 kJ to 16.7 MJ and use the distribution functions to show that neutrons and high energy x rays (15 keV) are produced under similar conditions when the yield is low. However, as the capsule starts to support a propagating burn due to alpha heating, the x rays and neutrons are produced under somewhat different conditions in different parts of the plasma. In particular, the x-ray production takes place mainly in the hot plastic ablator for the full yield ignition capsule under quite different plasma conditions from the DT region producing the 14 MeV neutrons, which results in x-ray images with larger radii than the corresponding neutron images. These same distribution functions can be applied to many other plasma physics experiments.
Use of fat-coated or heat-treated soybean meal for partial replacement of solvent-extracted soybean meal in the diets of early lactation dairy cows
Authors: Sahraei Belverdy Mohsen , Khadem Ali Akbar , Alamouti Ali A. , Khani Jaber , Calsamiglia Sergio
Published: December 2021

Context Soybean meal (SBM) is the most important protein source used to feed dairy cows, and methods have been developed to increase its nutritional value by protecting the proteins against rumen degradation. Protection of solvent-extracted SBM with saturated fats can achieve this, but effects on lactation performance and nutrient digestibility have not been investigated. Aims We evaluated effects on performance, nutrient digestibility and blood metabolites of high-yielding dairy cows when dietary solvent-extracted SBM was partially replaced with two fat-coated SBM products containing palmitic acid or a palmitic–stearic acid mix, or with standard heat-treated SBM. Methods Forty lactating Holstein cows were used in a randomised complete block design experiment with two phases each of 26 days (20 days of diet adaptation and 6 days of data collection). Experimental diets comprised (per kg DM) 271 g maize silage, 138 g other forages and 590 g concentrate, with 6.74 MJ net energy for lactation, 157 g crude protein and 366 g neutral detergent fibre. The control diet contained solvent-extracted SBM at 73.1 g/kg, which was partially replaced in the three test diets: two with fat-coated SBM (400 g fat/kg, enriched with palmitic acid or 50:50 palmitic:stearic acids), and one with heat-treated SBM. Diets were offered ad libitum during the experiment, and cows were milked three times daily. Key results Solvent-extracted SBM had significantly lower rumen undegraded protein concentration than the other three products. Dry matter intake was not affected by dietary treatment (27.7 ± 0.531 kg/day), nor was milk yield (47.8–50.3 kg/day), but milk fat yield tended to be greater (P < 0.10) with diets containing fat-coated than solvent-extracted SBM. The diet with palmitic acid coated SBM showed higher apparent total tract digestibilities of ether extract, dry matter, organic matter, crude protein and neutral detergent fibre than palmitic:stearic acid coated or solvent-extracted SBM treatments. Heat-treated SBM diet likewise showed higher digestibilities of ether extract, dry matter, organic matter, and acid and neutral detergent fibres than the solvent-extracted SBM diet. Concentrations of urea nitrogen in plasma and milk were not affected by treatment. Conclusions Feeding heat-treated or fat-coated SBM did not increase milk production of high-yielding cows; however, use of fat-coated SBM increased milk fat yield. Both palmitic acid coating and heat treatment improved total tract digestibility. Implications Feeding fat-coated SBM to dairy cows can protect SBM in the rumen and increase milk fat yield.
Algorithmic amplification of politics on Twitter
Authors: Huszár Ferenc , Ktena Sofia Ira , O’Brien Conor , Belli Luca , Schlaikjer Andrew , Hardt Moritz
Published: December 2021

Significance

The role of social media in political discourse has been the topic of intense scholarly and public debate. Politicians and commentators from all sides allege that Twitter’s algorithms amplify their opponents’ voices, or silence theirs. Policy makers and researchers have thus called for increased transparency on how algorithms influence exposure to political content on the platform. Based on a massive-scale experiment involving millions of Twitter users, a fine-grained analysis of political parties in seven countries, and 6.2 million news articles shared in the United States, this study carries out the most comprehensive audit of an algorithmic recommender system and its effects on political content. Results unveil that the political right enjoys higher amplification compared to the political left.
Lipidome profiling with Raman microspectroscopy identifies macrophage response to surface topographies of implant materials
Authors: Feuerer Nora , Marzi Julia , Brauchle Eva M. , Carvajal Berrio Daniel A. , Billing Florian , Weiss Martin , Jakobi Meike , Schneiderhan-Marra Nicole , Shipp Christopher , Schenke-Layland Katja
Published: December 2021

Significance

Macrophage plasticity and activation dynamics are under intense investigation because their full complexity cannot be captured by the few predefined markers that are commonly used. Macrophages are highly adherent and respond to surface microstructures in a sensitive manner. Here, we use Raman microspectroscopy and Raman imaging to study the macrophage response to defined activation stimuli and transfer these findings to macrophages cultured on titanium with varying surface roughness. We show that Raman-based methods can discriminate between macrophage phenotypes noninvasively and without the need to use antibody-based cell markers.
Active nematic order and dynamic lane formation of microtubules driven by membrane-bound diffusing motors
Authors: Memarian Fereshteh L. , Lopes Joseph D. , Schwarzendahl Fabian Jan , Athani Madhuvanthi Guruprasad , Sarpangala Niranjan , Gopinathan Ajay , Beller Daniel A. , Dasbiswas Kinjal , Hirst Linda S.
Published: December 2021

Significance

Active nematics are ordered liquid crystalline fluids that exhibit spontaneous persistent flows and collective dynamics. The development of motile biopolymer systems inspired by nature has recently attracted considerable attention to out-of-equilibrium soft materials. We report the formation of an active nematic in which microtubules are propelled by kinesin motors coupled to a lipid membrane substrate. The system exhibits apolar order in a globally aligned nematic phase and locally ordered dynamic lanes. Use of a fluid substrate represents a significant advance for active matter as it allows for spatial re-organization of motors, which generate force, in response to the dynamics of the aligning microtubules. This self-organized feedback mechanism may have implications in vivo and for engineering efficient dynamic and reconfigurable materials.
Slovak comparative correlatives
Authors: Horsch Jakob
Published: December 2021

Comparative Correlatives (CCs) are biclausal constructions (e.g.The harder you work, the more you earn) that have complex semantics and form. This is the first construction grammar-based corpus study to investigate Slovak CCs, based on a 500-token sample. I argue that intra-clausal word-order phenomena can be explained through processing efficiency, based on Hawkins’ principle of Early Immediate Constituents (2004), and I use covarying-collexeme analysis (Stefanowitsch & Gries 2005) to provide evidence for the existence of meso-constructions. The findings of this study contribute to construction grammar’s “aspirations toward universal applicability” (Fried 2017: 249), proving that the theory is also suitable for analysis of syntactic patterns in Slavic languages.
Plasma surface engineering for manmade soft materials: a review
Authors: Hegemann Dirk , Gaiser Sandra
Published: December 2021

Manmade soft materials are important in a wide range of technological applications and play a key role in the development of future technologies, mainly at the interface of synthetic and biological components. They include gels and hydrogels, elastomers, structural and packaging materials, micro and nanoparticles as well as biological materials. Soft materials can be distinguished from liquids owing to their defined shape and from hard materials by the deformability of their shape. This review article provides an overview of recent progress on the plasma engineering and processing of softer materials, especially in the area of synthesis, surface modification, etching, and deposition. The article aims to demonstrate the extensive range of plasma surface engineering as used to form, modify, and coat soft materials focusing on material properties and potential applications. In general, the plasma provides highly energetic, non-equilibrium conditions at material surfaces requiring to adjust the conditions for plasma–surface interaction to account for the specifics of soft matter, which holds independent of the used plasma source. Plasma-induced crosslinking and polymerization of liquids is discussed to transform them into gel-like materials as well as to modify the surface region of viscous liquids. A major field covers the plasma surface engineering of manmade soft materials with the help of gaseous reactive species yielding ablation, nanostructuring, functionalization, crosslinking, stiffening, and/or deposition to obtain demanded surface properties or adhesion to dissimilar materials. Finally, plasma engineering of rigid materials is considered to induce surface softening for the enhanced contact with tissues, to allow interaction in aqueous media, and to support bonding to soft matter. The potential and future perspectives of plasma engineering will be discussed in this review to contribute to a higher knowledge of plasma interaction with sensitive materials such as soft matter.
Enhanced thermoelectric properties of polycrystalline CuCrS2−x
Se
x
(x = 0, 0.5, 1.0, 1.5, 2) samples by replacing chalcogens and sintering
Authors: Romanenko A I , Chebanova G E , Katamanin I N , Drozhzhin M V , Artemkina S B , Han M-K , Kim S-J , Wang Hongchao
Published: December 2021

The optimization of thermoelectric properties of the CuCrS

2
−
x

Se
x
(x = 0, 0.5, 1.0, 1.5, 2) samples was achieved by substitution in anionic sublattice and sintering at high temperature. The maximum power factor PF ∼ 0.3 mW (m·K)−2 among a series of samples with chalcogen substitution was obtained for CuCrS0.5Se1.5 sample at T = 300 K. The sintering made it possible to obtain the maximum value PF ∼ 2.1 mW (m·K)−2 for CuCrSe2 sample. This is due to a more than threefold increase in the thermopower S(T) in CuCrSe2 sample with a spin-orbital interaction in comparison with CuCrS0.5Se1.5 sample with the same optimal electrical conductivity σ (

σ
∼

100 S cm−1), but without spin-orbital interaction. In CuCrSe2 sample, sintering effectively reduced the σ to an optimal value, suppressed of the magnetic phase transition in the range of 50–100 K, and the weak localization were replaced by weak antilocalization indicating the appearance of strong spin-orbit interaction below 20 K. As a result, an additional contribution to the S(T) appeared due to the filtration of current carriers caused by the strong spin-orbit interaction. The effect of grain boundaries on the properties σ and S(T) of the samples was investigated. It was established that polycrystalline samples with a high sulfur content were low-conductivity materials consisting of high-conductivity crystallites with the charge carriers concentration

n
∼

10

20

cm−3 separated by low-conductivity grain boundaries with fluctuation-induced tunneling conductivity. Both the replacement of sulfur with selenium and sintering led to a decrease in the energy barriers connecting grain boundaries. Selenium-dominated samples (CuCrS0.5Se1.5 and CuCrSe2) had high electrical conductivity with negligible energy barriers between grain boundaries. Logarithmic quantum corrections to the electrical conductivity was observed below 20 K, which indicated a quasi-two-dimensional electron transport in these samples.
Chiral Majorana edge modes and vortex Majorana zero modes in superconducting antiferromagnetic topological insulator
Authors: Huang Beibing , Yang Xiaosen , Zhang Qinfang , Xu Ning
Published: December 2021

The antiferromagnetic topological insulator (AFTI) is topologically protected by the combined time-reversal and translational symmetry

T

c

. In this paper we investigate the effects of the s-wave superconducting pairings on the multilayers of AFTI, which breaks

T

c

symmetry and can realize quantum anomalous Hall insulator with unit Chern number. For the weakly coupled pairings, the system corresponds to the topological superconductor (TSC) with the Chern number C = ±2. We answer the following questions whether the local Chern numbers and chiral Majorana edge modes of such a TSC distribute around the surface layers. By the numerical calculations based on a theoretic model of AFTI, we find that when the local Chern numbers are always dominated by the surface layers, the wavefunctions of chiral Majorana edge modes must not localize on the surface layers and show a smooth crossover from spatially occupying all layers to only distributing near the surface layers, similar to the hinge states in a three dimensional second-order topological phases. The latter phase, denoted by the hinged TSC, can be distinguished from the former phase by the measurements of the local density of state. In addition we also study the superconducting vortex phase transition in this system and find that the exchange field in the AFTI not only enlarges the phase space of topological vortex phase but also enhances its topological stability. These conclusions will stimulate the investigations on superconducting effects of AFTI and drive the studies on chiral Majorana edge modes and vortex Majorana zero modes into a new era.
Synergetic effect of Si addition on mechanical properties in face-centered-cubic high entropy alloys: a first-principles study
Authors: Tsuru Tomohito , Lobzenko Ivan , Wei Daixiu
Published: December 2021

High-entropy alloys (HEA) have been receiving increased attention for their excellent mechanical properties. Our recent study revealed that Si-doped face-centered cubic (FCC) HEAs have great potential to improve both strength and ductility. Here, we carried out first-principles calculations in cooperation with Monte Carlo simulation and structural factor analysis to explore the effect of Si addition on the macroscopic mechanical properties. As a result, Si addition increased the local lattice distortion and the stacking fault energy (SFE). Furthermore, the short-range order formation in Si-doped alloy caused highly fluctuated SFE. Thus, the heterogeneous solid solution states in which low and high stacking fault regions are distributed into the matrix were nucleated. This unique feature in Si-doped FCC-HEA induces ultrafine twin formation in Si-doped alloys, which can be a dominant factor in improving both strength and ductility.
Small-diameter p-type SnS nanowire photodetectors and phototransistors with low-noise and high-performance
Authors: Chen Ruoling , Li Long , Jiang Long , Yu Xiangxiang , Zhu Desheng , Xiong Yan , Zheng Dingshan , Yang Wenxing
Published: December 2021

P-type nanostructured photodetectors and phototransistors have been widely used in the field of photodetection due to their excellent electrical and optoelectronic characteristics. However, the large dark current of p-type photodetectors will limit the detectivity. Herein, we synthesized small-diameter single-crystalline p-type SnS nanowires (NWs) and then fabricated single SnS NW photodetectors and phototransistors. The device exhibits low noise and low dark current, and its noise current power is as low as 2.4 × 10−28 A2. Under 830 nm illumination and low power density of 0.12 mW cm−2, the photoconductive gain, responsivity and detectivity of the photodetector are as high as 3.9 × 102, 2.6 × 102 A W−1 and 1.8 × 1013 Jones, respectively, at zero gate voltage. The rise and fall time of response are about 9.6 and 14 ms. The experimental results show that the small-diameter p-type SnS NWs have broad application prospects in high-performance and low-power photodetectors with high sensitivity, fast response speed and wide spectrum detection in the future.
Ion dynamics driven by a strongly nonlinear plasma wake
Authors: Khudiakov V K , Lotov K V , Downer M C
Published: December 2021

In plasma wakefield accelerators, the wave excited in the plasma eventually breaks and leaves behind slowly changing fields and currents that perturb the ion density background. We study this process numerically using the example of a Facility for Advanced aCcelerator Experimental Tests (FACET) experiment where the wave is excited by an electron bunch in the bubble regime in a radially bounded plasma. Four physical effects underlie the dynamics of ions: (1) attraction of ions toward the axis by the fields of the driver and the wave, resulting in formation of a density peak, (2) generation of ion-acoustic solitons following the decay of the density peak, (3) positive plasma charging after wave breaking, leading to acceleration of some ions in the radial direction, and (4) plasma pinching by the current generated during the wave-breaking. The interplay of these effects results in the formation of various radial density profiles, which are difficult to produce in any other way.
Neural network based fast prediction of β

N
limits in HL-2M
Authors: Zhao Y F , Liu Y Q , Wang S , Hao G Z , Wang Z X , Yang Z Y , Li B , Li J X , Chen H T , Xu M , Duan X R
Published: December 2021

Artificial neural networks (NNs) are trained, based on the numerical database, to predict the no-wall and ideal-wall β

N
limits, due to onset of the n = 1 (n is the toroidal mode number) ideal external kink instability, for the HL-2M tokamak. The database is constructed by toroidal computations utilizing both the equilibrium code CHEASE (Lütjens et al 1992 Comput. Phys. Commun.
69 287) and the stability code MARS-F (Liu et al 2000 Phys. Plasmas
7 3681). The stability results show that (1) the plasma elongation generally enhances both β

N
limits, for either positive or negative triangularity plasmas; (2) the effect is more pronounced for positive triangularity plasmas; (3) the computed no-wall β

N
limit linearly scales with the plasma internal inductance, with the proportionality coefficient ranging between 1 and 5 for HL-2M; (4) the no-wall limit substantially decreases with increasing pressure peaking factor. Furthermore, both the NN model and the convolutional neural network (CNN) model are trained and tested, producing consistent results. The trained NNs predict both the no-wall and ideal-wall limits with as high as 95% accuracy, compared to those directly computed by the stability code. Additional test cases, produced by the Tokamak Simulation Code (Jardin et al 1993 Nucl. Fusion
33 371), also show reasonable performance of the trained NNs, with the relative error being within 10%. The constructed database provides effective references for the future HL-2M operations. The trained NNs can be used as a real-time monitor for disruption prevention in the HL-2M experiments, or serve as part of the integrated modeling tools for ideal kink stability analysis.
Novel ionic bioartificial muscles based on ionically crosslinked multi-walled carbon nanotubes-mediated bacterial cellulose membranes and PEDOT:PSS electrodes
Authors: Wang Yaofeng , Wang Fan , Kong Yang , Wang Lei , Li Qinchuan
Published: December 2021

High-performance bioartificial muscles with low-cost, large bending deformation, low actuation voltage, and fast response time have drawn extensive attention as the development of human-friendly electronics in recent years. Here, we report a high-performance ionic bioartificial muscle based on the bacterial cellulose (BC)/ionic liquid (IL)/multi-walled carbon nanotubes (MWCNT) nanocomposite membrane and PEDOT:PSS electrode. The developed ionic actuator exhibits excellent electro-chemo-mechanical properties, which are ascribed to its high ionic conductivity, large specific capacitance, and ionically crosslinked structure resulting from the strong ionic interaction and physical crosslinking among BC, IL, and MWCNT. In particular, the proposed BC-IL-MWCNT (0.10 wt%) nanocomposite exhibited significant increments of Young’s modulus up to 75% and specific capacitance up to 77%, leading to 2.5 times larger bending deformation than that of the BC-IL actuator. More interestingly, bioinspired applications containing artificial soft robotic finger and grapple robot were successfully demonstrated based on high-performance BC-IL-MWCNT actuator with excellent sensitivity and controllability. Thus, the newly proposed BC-IL-MWCNT bioartificial muscle will offer a viable pathway for developing next-generation artificial muscles, soft robotics, wearable electronic products, flexible tactile devices, and biomedical instruments.
Current-induced self-organisation of mixed superconducting states
Authors: Brems Xaver S , Mühlbauer Sebastian , Córdoba-Camacho Wilmer Y , Shanenko Arkady A , Vagov Alexei , Albino Aguiar José , Cubitt Robert
Published: December 2021

Small-angle neutron scattering is used in combination with transport measurements to investigate the current-induced effects on the morphology of the intermediate mixed state (IMS) domains in the intertype superconductor niobium. We report the robust self-organisation of the vortex lattice domains to elongated parallel stripes perpendicular to the applied current in a steady-state. The experimental results for the formation of the superstructure are supported by theoretical calculations, which highlight important details of the vortex matter evolution. The investigation demonstrates a mechanism of a spontaneous pattern formation that is closely related to the universal physics governing the IMS in low-κ superconductors.
Improving photoluminescence, optical and electrical characteristics of PMMA films with gamma irradiation
Authors: Zaki M F , Shubayr N , Radwan R M , Alashban Y
Published: December 2021

Polymeric materials are macromolecules, essentially a combination of numerous repeated subunits. Polymers are innovative and advanced materials that currently have a strong impact on our daily lives. In recent years, polymer use has been prominent due to the materials’ distinctive properties; thus, they entered different fields of science, technology and industrial-biomedical applications.The improvement of photoluminescence, optical and electrical characteristics of non-conducting Poly(methyl methacrylate) (PMMA) films was studied. Upon gamma irradiation of various doses, the photophysical and electrical properties of PMMA films were investigated using photoluminescence spectroscopy, ultraviolet–visible (UV–vis) spectroscopy and the LCR Meter Bridge Circuit technique. The fluorescent response improved the photoluminescence (PL) spectral emission peaks according to gamma values. Strong fluorescence peaks appeared with the highest gamma dose. The UV–Vis results revealed a significant red-shift in the absorption edge as gamma doses increased. This shift exhibits a continuous decrease in the energy band gap values (from 3.50 to 2.60 eV for direct transition and from 3.05 to 1.55 eV for indirect transition). This was due to the formation of carbon clusters, which led to an increase in the electrical conductivity and improved the dielectric parameters of the irradiated PMMA films. Among a variety of measurements presented and discussed in the present study, the electrical measurements showed improved electrical characteristics of gamma-irradiated PMMA films.
SELCIE: a tool for investigating the chameleon field of arbitrary sources
Authors: Briddon Chad , Burrage Clare , Moss Adam , Tamosiunas Andrius
Published: December 2021

The chameleon model is a modified gravity theory that introduces an additional scalar field that couples to matter through a conformal coupling. This `chameleon field' possesses a screening mechanism through a nonlinear self-interaction term which allows the field to affect cosmological observables in diffuse environments whilst still being consistent with current local experimental constraints. Due to the self-interaction term the equations of motion of the field are nonlinear and therefore difficult to solve analytically. The analytic solutions that do exist in the literature are either approximate solutions and or only apply to highly symmetric systems. In this work we introduce the software package SELCIE (https://github.com/C-Briddon/SELCIE.git). This package equips the user with tools to construct an arbitrary system of mass distributions and then to calculate the corresponding solution to the chameleon field equation. It accomplishes this by using the finite element method and either the Picard or Newton nonlinear solving methods. We compared the results produced by SELCIE with analytic results from the literature including discrete and continuous density distributions. We found strong (sub-percentage) agreement between the solutions calculated by SELCIE and the analytic solutions.
Mixed dark matter: matter power spectrum and halo mass function
Authors: Parimbelli G. , Scelfo G. , Giri S.K. , Schneider A. , Archidiacono M. , Camera S. , Viel M.
Published: December 2021

We investigate and quantify the impact of mixed (cold and
warm) dark matter models on large-scale structure observables. In
this scenario, dark matter comes in two phases, a cold one (CDM) and
a warm one (WDM): the presence of the latter causes a suppression in
the matter power spectrum which is allowed by current constraints
and may be detected in present-day and upcoming surveys. We run a
large set of N-body simulations in order to build an efficient and
accurate emulator to predict the aforementioned suppression with
percent precision over a wide range of values for the WDM mass,
Mwdm, and its fraction with respect to the totality of dark
matter, fwdm. The suppression in the matter power spectrum is
found to be independent of changes in the cosmological parameters at
the 2% level for k≲ 10 h/Mpc and z≤ 3.5. In the
same ranges, by applying a baryonification procedure on both
ΛCDM and CWDM simulations to account for the effect of feedback, we
find a similar level of agreement between the two scenarios. We
examine the impact that such suppression has on weak lensing and
angular galaxy clustering power spectra. Finally, we discuss the
impact of mixed dark matter on the shape of the halo mass function
and which analytical prescription yields the best agreement with
simulations. We provide the reader with an application to galaxy
cluster number counts.
Emulation of baryonic effects on the matter power spectrum and constraints from galaxy cluster data
Authors: Giri Sambit K. , Schneider Aurel
Published: December 2021

Baryonic feedback effects consist of a major systematic for upcoming weak-lensing and galaxy-clustering surveys. In this paper, we present an emulator for the baryonic suppression of the matter power spectrum. The emulator is based on the baryonification model, containing seven free parameters that are connected to the gas profiles and stellar abundances in haloes. We show that with the baryonic emulator, we can not only recover the power spectra of hydro-dynamical simulations at sub-percent precision, but also establish a connection between the baryonic suppression of the power spectrum and the gas and stellar fractions in haloes. This connection allows us to predict the expected deviation from a dark-matter-only power spectrum using measured X-ray gas fractions of galaxy groups and clusters. With these measurements, we constrain the suppression to exceed the percent-level at k=0.1-0.4 h/Mpc and to reach a maximum of 20-28 percent at around k∼ 7 h/Mpc (68 percent confidence level). As a further step, we also perform a detailed parameter study and we present a minimum set of four baryonic parameters that are required to recover the scale and redshift dependence observed in hydro-dynamical simulations. The baryonic emulator can be found at https://github.com/sambit-giri/BCemu.
Ultralight bosons for strong gravity applications from simple Standard Model extensions
Authors: Freitas Felipe F. , Herdeiro Carlos A.R. , Morais António P. , Onofre António , Pasechnik Roman , Radu Eugen , Sanchis-Gual Nicolas , Santos Rui
Published: December 2021

We construct families, and concrete examples, of simple
extensions of the Standard Model that can yield ultralight real or
complex vectors or scalars with potential astrophysical
relevance. Specifically, the mass range for these putative
fundamental bosons (∼ 10-10-10-20 eV) would lead
dynamically to both new non-black hole compact objects (bosonic
stars) and new non-Kerr black holes, with masses of ∼ M⊙
to ∼ 1010 M⊙, corresponding to the mass range of
astrophysical black hole candidates (from stellar mass to
supermassive). For each model, we study the properties of the mass
spectrum and interactions after spontaneous symmetry breaking,
discuss its theoretical viability and caveats, as well as some of
its potential and most relevant phenomenological implications
linking them to the physics of compact objects.
Halo-independent analysis of direct dark matter detection through electron scattering
Authors: Chen Muping , Gelmini Graciela B. , Takhistov Volodymyr
Published: December 2021

Sub-GeV mass dark matter particles whose collisions with nuclei would not deposit sufficient energy to be detected, could instead be revealed through their interaction with electrons.
Analyses of data from direct detection experiments usually require assuming a local dark matter halo velocity distribution. In the halo-independent analysis method, properties of this distribution are instead inferred from direct dark matter detection data, which allows then to compare different data without making any assumption on the uncertain local dark halo characteristics. This method has so far been developed for and applied to dark matter scattering off nuclei. Here we demonstrate how this analysis can be applied to scattering off electrons.
Effect of proprioceptive stimulation using a soft robotic glove on motor activation and brain connectivity in stroke survivors
Authors: Nasrallah Fatima A , Mohamed Abdalla Z , Yap Hong Kai , Lai Hwa Sen , Yeow Chen-Hua , Lim Jeong Hoon
Published: December 2021

Objective. Soft-robotic-assisted training may improve motor function during post-stroke recovery, but the underlying physiological changes are not clearly understood. We applied a single-session of intensive proprioceptive stimulation to stroke survivors using a soft robotic glove to delineate its short-term influence on brain functional activity and connectivity. Approach. In this study, we utilized task-based and resting-state functional magnetic resonance imaging (fMRI) to characterize the changes in different brain networks following a soft robotic intervention. Nine stroke patients with hemiplegic upper limb engaged in resting-state and motor-task fMRI. The motor tasks comprised two conditions: active movement of fingers (active task) and glove-assisted active movement using a robotic glove (glove-assisted task), both with visual instruction. Each task was performed using bilateral hands simultaneously or the affected hand only. The same set of experiments was repeated following a 30 min treatment of continuous passive motion (CPM) using a robotic glove. Main results. On simultaneous bimanual movement, increased activation of supplementary motor area (SMA) and primary motor area (M1) were observed after CPM treatment compared to the pre-treatment condition, both in active and glove-assisted task. However, when performing the tasks solely using the affected hand, the phenomena of increased activity were not observed either in active or glove-assisted task. The comparison of the resting-state fMRI between before and after CPM showed the connectivity of the supramarginal gyrus and SMA was increased in the somatosensory network and salience network. Significance. This study demonstrates how passive motion exercise activates M1 and SMA in the post-stroke brain. The effective proprioceptive motor integration seen in bimanual exercise in contrast to the unilateral affected hand exercise suggests that the unaffected hemisphere might reconfigure connectivity to supplement damaged neural networks in the affected hemisphere. The somatosensory modulation rendered by the intense proprioceptive stimulation would affect the motor learning process in stroke survivors.
Effects of virtual reality-based motor rehabilitation: a systematic review of fMRI studies
Authors: Feitosa Jamille A , Fernandes Corina A , Casseb Raphael F , Castellano Gabriela
Published: December 2021

Background. The use of virtual reality (VR) as a rehabilitation tool has been shown to induce motor and cognitive improvements in different populations. Functional magnetic resonance imaging (fMRI) has been used to investigate neuroplasticity resulting from these treatments. We hypothesize that VR rehabilitation induces functional improvement and brain changes that can be detected by fMRI. Objective. To systematically review the effects of VR intervention on the cortical reorganization measured by fMRI and associated with functional improvement. Approach. We performed a systematic review of studies published between 2005 and 2021. Papers were retrieved from six databases using the following keywords: ‘motor rehabilitation’, ‘fMRI’ and ‘virtual reality’. Case studies, pre-post studies, cross-sectional studies, and randomized controlled trials published were included. Manuscripts were assessed by The National Institutes of Health study quality assessment tools to determine their quality. Main results. Twenty-three articles met our eligibility criteria: 18 about VR rehabilitation in stroke and five on other clinical conditions (older adults, cerebral palsy, and Parkinson’s disease). Changes in neural patterns of activation and reorganization were revealed in both the ipsilesional and the contralesional hemispheres. Results were located mainly in the primary motor cortex, sensorimotor cortex and supplementary motor area in post-stroke patients in the acute, subacute, and chronic rehabilitation phases, and were associated with functional improvement after VR intervention. Similar effects were observed in older adults and in patients with other neurological diseases with improved performance. Significance. Most stroke-related studies showed either restoration to normal or increase of activation patterns or relateralization at/to the ipsilesional hemisphere, with some also reporting a decrease in activity or extent of activation after VR therapy. In general, VR intervention demonstrated evidence of efficacy both in neurological rehabilitation and in performance improvement of older adults, accompanied by fMRI evidence of brain reorganization.
Anomalous tungsten transport driven by ion temperature gradient turbulence
Authors: Xu Shaokang , Maeyama S. , Watanabe T.-H.
Published: December 2021

The present study reveals that the anomalous tungsten particle transport based on the nonlinear gyrokinetic simulations shares some similarities with that of the linear gyrokinetic study, meanwhile there exists some significant differences. In particular, nonlinear excitation of the linearly stable modes plays a non-negligible role in the anomalous tungsten particle transport. The highlighted results are the downshift of the critical density gradient for zero tungsten particle transport and the modification of the poloidal profile of the outward tungsten particle transport, which are both related to the small scale turbulent fluctuations. The former one is due to the outward particle convection produced by the linearly stable modes. The later one is brought by both the linearly stable modes and the large-scale eddies with finite ballooning angle, which flatten the poloidal profile of the particle diffusion and further shift the peak positions of the strongest outward particle transport to the high poloidal angle regions.
X-ray characterization of BUSARD chip: A HV-SOI monolithic particle detector with pixel sensors under the buried oxide
Authors: Alcalde Bessia F. , Lipovetzky J. , Perić I.
Published: December 2021

This work presents the design of BUSARD, an application
specific integrated circuit (ASIC) for the detection of ionizing
particles. The ASIC is a monolithic active pixel sensor which has
been fabricated in a High-Voltage Silicon-On-Insulator (HV-SOI)
process that allows the fabrication of a buried N+ diffusion below
the Buried OXide (BOX) as a standard processing step. The first
version of the chip, BUSARD-A, takes advantage of this buried
diffusion as an ionizing particle sensor. It includes a small array
of 13×13 pixels, with a pitch of 80 μm, and each pixel
has one buried diffusion with a charge amplifier, discriminator with
offset tuning and digital processing. The detector has several
operation modes including particle counting and Time-over-Threshold
(ToT). An initial X-ray characterization of the detector was carried
out, obtaining several pulse height and ToT spectra, which then were
used to perform the energy calibration of the device. The Molybdenum
𝐊α emission was measured with a standard
deviation of 127 e- of ENC by using the analog pulse output,
and with 276 e- of ENC by using the ToT digital output. The
resolution in ToT mode is dominated by the pixel-to-pixel
variation.
Scintillation light increase of carbontetrafluoride gas at low temperature
Authors: Mizukoshi K. , Maeda T. , Nakano Y. , Higashino S. , Miuchi K.
Published: December 2021

Scintillation detector is widely used for the particle detection in the field of particle physics.
Particle detectors containing fluorine-19 (19F) are known to have advantages for Weakly Interacting Massive Particles (WIMPs) dark matter search, especially for spin-dependent interactions with WIMPs due to its spin structure.
In this study, the scintillation properties of carbontetrafluoride (CF4) gas at low temperature were evaluated because its temperature dependence of light yield has not been measured.
We evaluated the light yield by cooling the gas from room temperature (300 K) to 263 K.
As a result, the light yield of CF4 was found to increase by (41.0 ± 4.0stat. ± 6.6syst.)% and the energy resolution was also found to improve at low temperature.
Pathologies of the hearing aid under the influence of global climate change and ecology
Authors: Ryzhkin N , Ivanova A , Savchenko Y , Polin R , Korobov I
Published: December 2021

This article discusses the pathological changes of the hearing aid in connection with the deterioration of the environmental situation around the world, presents the psychophysical features that deal with the struggle of children with hearing impairment (hard of hearing and deaf). The method of physical education in the course of classes in the wrestling section for the adaptation and harmonious physical development of hard-of-hearing children is proposed and investigated. In our opinion, exercises in wrestling contribute to the development of a number of many valuable physical and psychological qualities that are necessary for a child with hearing impairment. The hypothesis of the study is based on the assumption that the inclusion of special developed methods for wrestling will allow to achieve significant results in a short time in children with hearing impairment. The use of wrestling exercises allows you to maximize the development of the functions of these analyzers for deaf children to more effectively participate in the compensation of lost qualities as a result of impaired hearing aid.