bluuebunny/crossref_metadata_2025_split huggingface dataset:
ZnO nanoparticles embedded silk fibroin—a piezoelectric composite for nanogenerator applications
Authors: Sarkar Lisa , Sushma Mudigunda V , Yalagala Bhavani Prasad , Rengan Aravind Kumar , Singh Shiv Govind , Vanjari Siva Rama Krishna 
Published: March 2022

Abstract
This paper demonstrates a flexible nanogenerator (NG) using Silk-Zinc Oxide (ZnO) composite by exploiting the inherent piezoelectric properties of silk and ZnO. A direct precipitation method was employed to synthesize Zinc Oxide nanoparticles (NPs). Silk-ZnO composite film was then prepared by spin-coating the homogenous silk-ZnO solution. The composition and morphology of silk-ZnO composite were analyzed using various standard characterization procedures. The biocompatibility study of the composite film was also performed through cell viability testing. The utility of as prepared composites was demonstrated through the fabrication of piezoelectric nanogenerator. This hybrid nanogenerator was capable to generate a maximum open circuit voltage of 25 V (peak to peak value) in the bending state for a specific ZnO concentration. The output response of the nanogenerator exhibited a good correlation with the bending angle of the device. A peak outputpower density of 6.67 mW cm−3 was achieved from the nanogenerator. The fabricated prototype is efficient to light-up commercial red LEDs and to harvest energy from human body movement. The piezoelectric coefficient (d
33) of silk-ZnO composite film was also experimentally figured out.
Negative out-of-plane Poisson’s ratio of bilayer graphane
Authors: Ho Viet Hung , Ho Duc Tam , Nguyen Cao Thang , Kim Sung Youb 
Published: March 2022

Abstract
With its excellent mechanical and thermal properties, bilayer graphane is a promising material for realizing future nanoelectromechanical systems. In this study, we focus on the auxetic behavior of bilayer graphane under external loading along various directions through atomistic simulations. We numerically and theoretically reveal the mechanism of the auxeticity in terms of intrinsic interactions between carbon atoms by constructing bilayer graphane. Given that the origin of the auxeticity is intrinsic rather than extrinsic, the work provides a novel technique to control the dimensions of nanoscale bilayer graphane by simply changing the external conditions without the requirement of complex structural design of the material.
Improving the photoresponse performance of monolayer MoS2 photodetector via local flexoelectric effect
Authors: Feng Pu , Zhao Sixiang , Dang Congcong , He Sixian , Li Ming , Zhao Liancheng , Gao Liming 
Published: March 2022

Abstract
Strain engineering is an effective means of modulating the optical and electrical properties of two-dimensional materials. The flexoelectric effect caused by inhomogeneous strain exists in most dielectric materials, which breaks the limit of the materials’ non-centrosymmetric structure for piezoelectric effect. However, there is a lack of understanding of the impact on optoelectronic behaviour of monolayer MoS2 photodetector via local flexoelectric effect triggered by biaxial strain. In this paper, we develop a probe tip (Pt)-MoS2-Au asymmetric Schottky barrier photodetector based on conductive atomic force microscopy to investigate the impact of flexoelectric effect on the photoresponse performance. Consequently, when the probe force increases from 24 nN to 720 nN, the photocurrent, responsivity and detectivity increase 28.5 times, 29.6 times and 5.3 times at forward bias under 365 nm light illumination, respectively. These results indicate that local flexoelectric effect plays a critical role to improve the photoresponse performance of photodetector. Our approach suggests a new route to improve the performance of photodetectors by introducing local flexoelectric polarization field, offering the potential for the application of strain modulated photoelectric devices.
Excitation of Alfvén eigenmodes by fusion-born alpha-particles in D-3He plasmas on JET
Authors: Kiptily V G , Kazakov Ye O , Nocente M , Ongena J , Belli F , Dreval M , Craciunescu T , Eriksson J , Fitzgerald M , Giacomelli L , Goloborodko V , Iliasova M V , Khilkevitch E M , Rigamonti D , Sahlberg A , Salewski M , Shevelev A E , Garcia J , Oliver H J C , Sharapov S E , Stancar Z , Weisen H 
Published: March 2022

Abstract
Alfvén eigenmode (AE) instabilities driven by alpha-particles have been observed in D-3He fusion experiments on the Joint European Torus (JET) with the ITER-like wall. For the efficient generation of fusion alpha-particles from D-3He fusion reaction, the three-ion radio frequency scenario was used to accelerate the neutral beam injection 100 keV deuterons to higher energies in the core of mixed D-3He plasmas at high concentrations of 3He. A large variety of fast-ion driven magnetohydrodynamic modes were observed, including the elliptical Alfvén eigenmodes (EAEs) with mode numbers n = −1 and axisymmetric modes with n = 0 in the frequency range of EAEs. The simultaneous observation of these modes indicates the presence of rather strong alpha-particle population in the plasma with a ‘bump-on-tail’ shaped velocity distribution. Linear stability analysis and Fokker–Planck calculations support the observations. Experimental evidence of the AEs excitation by fusion-born alpha-particles in the D-3He plasma is provided by neutron and gamma-ray diagnostics as well as fast-ion loss measurements. We discuss an experimental proposal for the planned full-scale D-T plasma experiments on JET based on the physics insights gained from these experiments.
New phenomena in laser-assisted leptonic decays of the negatively charged boson W
−
Authors: Mouslih S , Jakha M , Dahiri I , Taj S , Manaut B , Siher E 
Published: March 2022

Abstract
The majority of studies and experiments performed at electron-positron colliders over the last two decades have focused on studying W and Z weak force-carrying bosons and accurately measuring all their properties, not only because they play an important role in establishing Standard Model theory and providing an accurate test of its predictions of particle interactions, but also because they are a unique tool for probing manifestations of the new physics beyond the standard model. Therefore, it would be particularly important to discuss some of the new phenomena and changes that can arise in these bosons when their decay occurs under an external electromagnetic field. In a recent paper, we investigated the laser effect on the final products of Z boson decay and found that laser had an unprecedented effect on branching ratios. In this work and within the standard Glashow-Weinberg-Salam model of electroweak interactions, we study theoretically the leptonic decay of the W
−-boson

(

W

−

→

ℓ

−

ν

¯

ℓ

)

in the presence of a circularly polarized electromagnetic field and we examine the laser effect, in terms of its field strength and frequency, on the leptonic decay rate and the phenomenon of multiphoton processes. The calculations are carried out using the exact relativistic wave functions of charged particles in an electromagnetic field. It was found that the laser significantly contributed to reducing the probability of W
−-boson decay. We show that the laser-assisted decay rate is equal to the laser-free one only when the famous Kroll-Watson sum rule is fulfilled. The notable effect of the laser on the leptonic decay rate was reasonably interpreted by the well-known quantum Zeno effect or by the opening of channels other than leptonic ones to decay. This work will pave the way for an upcoming one to study the hadronic decay of the W
−-boson and then explore the laser effect on its lifetime and branching ratios.
Vibrational resonance and bifurcation in a fractional order quintic system with distributed time delay
Authors: Ning Lijuan , Zhao Keya 
Published: March 2022

Abstract
In this paper, vibrational resonance and bifurcation phenomena are investigated in the fractional order quintic system with distributed time delay. The approximate theoretical expression for the response amplitude at low frequency is derived by using the method of fast and slow variable separation. In the presence of fractional order and distributed time delay, the vibrational resonance and bifurcation are explored in the single-well, double-well and triple-well potentials, respectively. It is found that the decay rate of the kernel function σ can cause bifurcation, which is closely related to the high frequency excitation amplitude F. It is worth noting that the range of

ω

r

2

in which resonance occurs twice, three and four times decreases with the increase of σ. Furthermore, appropriate values of the decay rate σ, fractional order α and high frequency excitation amplitude F will enable to improve the response amplitude Q. The high match of the numerical simulation and analytical results confirms the validity of the theoretical analysis.
Primordial black hole formation with full numerical relativity
Authors: de Jong Eloy , Aurrekoetxea Josu C. , Lim Eugene A. 
Published: March 2022

Abstract
We study the formation of black holes from subhorizon and superhorizon perturbations in a matter dominated universe with 3+1D numerical relativity simulations. We find that there are two primary mechanisms of formation depending on the initial perturbation's mass and geometry — via direct collapse of the initial overdensity and via post-collapse accretion of the ambient dark matter. In particular, for the latter case, the initial perturbation does not have to satisfy the hoop conjecture for a black hole to form. In both cases, the duration of the formation the process is around a Hubble time, and the initial mass of the black hole is M
BH ∼ 10-2
H
-1
M
Pl
2. Post formation, we find that the PBH undergoes rapid mass growth beyond the self-similar limit M
BH α H
-1, at least initially. We argue that this implies that most of the final mass of the PBH is accreted from its ambient surroundings post formation.
Constraining primordial black holes as dark matter using the global 21-cm signal with X-ray heating and excess radio background
Authors: Mittal Shikhar , Ray Anupam , Kulkarni Girish , Dasgupta Basudeb 
Published: March 2022

Abstract
Using the global 21-cm signal measurement by the EDGES collaboration, we derive constraints on the fraction of the dark matter that is in the form of primordial black holes (PBHs) with masses in the range 1015–1017 g. Improving upon previous analyses, we consider the effect of the X-ray heating of the intergalactic medium on these constraints, and also use the full shape of the 21-cm absorption feature in our inference. In order to account for the anomalously deep absorption amplitude, we also consider an excess radio background motivated by LWA1 and ARCADE2 observations. Because the heating rate induced by PBH evaporation evolves slowly, the data favour a scenario in which PBH-induced heating is accompanied by X-ray heating. Also, for the same reason, using the full measurement across the EDGES observation band yields much stronger constraints on PBHs than just the redshift of absorption. We find that 21-cm observations exclude f
PBH ≳ 10-9.7 at 95% CL for M
PBH = 1015 g. This limit weakens approximately as M
4
PBH towards higher masses, thus providing the strongest constraints on ultralight evaporating PBHs as dark matter over the entire mass range 1015–1017 g. Under the assumption of a simple spherical gravitational collapse based on the Press-Schechter formalism, we also derive bounds on the curvature power spectrum at extremely small scales (k ∼ 1015 Mpc-1). This highlights the usefulness of global 21-cm measurements, including non-detections, across wide frequency bands for probing exotic physical processes.
Quasi-linearization and stability analysis of some self-dual, dark equations and a new dynamical system
†
Authors: Blackmore Denis , Prytula Mykola M , Prykarpatski Anatolij K 
Published: March 2022

Abstract
We describe a class of self-dual dark nonlinear dynamical systems a priori allowing their quasi-linearization, whose integrability can be effectively studied by means of a geometrically based gradient-holonomic approach. A special case of the self-dual dynamical system, parametrically dependent on a functional variable is considered, and the related integrability condition is formulated. Using this integrability scheme, we study a new self-dual, dark nonlinear dynamical system on a smooth functional manifold, which models the interaction of atmospheric magneto-sonic Alfvén plasma waves. We prove that this dynamical system possesses a Lax representation that allows its full direct linearization and compatible Poisson structures. Moreover, for this self-dual nonlinear dynamical system we construct an infinite hierarchy of mutually commuting conservation laws and prove its complete integrability.
Towards traceable dynamic pressure calibration using a shock tube with an optical probe for accurate phase determination
Authors: Amer Eynas , Jönsson Gustav , Arrhén Fredrik 
Published: March 2022

Abstract
In this paper, we introduce a robust method for dynamic characterization of pressure measuring systems used in time-varying pressure applications. The dynamic response of the pressure measuring systems in terms of sensitivity and phase as a function of frequency at various amplitudes of the measurand can be provided. The shock tube which is the candidate primary standard for dynamic pressure calibration at the National Laboratory for pressure, Sweden, was used to realize the dynamic pressure. The shock tube setup used in this study can realize reference pressure with amplitudes up to 1.7 MPa in the frequency range from below a kilohertz up to a megahertz. The amplitude of the realized step pressure was calculated using the Rankine–Hugoniot step relations. In addition, the accurate time of arrival of the generated shock at the device under test (DUT) was measured using an optical probe based on shadowgraphy. The optical detector has a response time in nanosecond time scale which is several orders of magnitude faster than the response time of any pressure measuring system. Hereby, the latency between physical stimuli and response of the DUT can be measured. By the knowledge of the amplitude and the accurate time of arrival of the reference step pressure, the transfer function of the DUT can be calculated and presented in Bode diagrams of sensitivity and phase response versus frequency. The uncertainty in sensitivity and phase measurements was estimated. The information provided by this work is useful for developing reliable models of dynamic pressure measuring system and provide accurate information about their dynamic response. That in turn will contribute to establish a traceability chain for dynamic pressure calibration.
Decoding ECoG signal into 3D hand translation using deep learning
Authors: Śliwowski Maciej , Martin Matthieu , Souloumiac Antoine , Blanchart Pierre , Aksenova Tetiana 
Published: March 2022

Abstract

Objective. Motor brain-computer interfaces (BCIs) are a promising technology that may enable motor-impaired people to interact with their environment. BCIs would potentially compensate for arm and hand function loss, which is the top priority for individuals with tetraplegia. Designing real-time and accurate BCI is crucial to make such devices useful, safe, and easy to use by patients in a real-life environment. Electrocorticography (ECoG)-based BCIs emerge as a good compromise between invasiveness of the recording device and good spatial and temporal resolution of the recorded signal. However, most ECoG signal decoders used to predict continuous hand movements are linear models. These models have a limited representational capacity and may fail to capture the relationship between ECoG signal features and continuous hand movements. Deep learning (DL) models, which are state-of-the-art in many problems, could be a solution to better capture this relationship. Approach. In this study, we tested several DL-based architectures to predict imagined 3D continuous hand translation using time-frequency features extracted from ECoG signals. The dataset used in the analysis is a part of a long-term clinical trial (ClinicalTrials.gov identifier: NCT02550522) and was acquired during a closed-loop experiment with a tetraplegic subject. The proposed architectures include multilayer perceptron, convolutional neural networks (CNNs), and long short-term memory networks (LSTM). The accuracy of the DL-based and multilinear models was compared offline using cosine similarity. Main results. Our results show that CNN-based architectures outperform the current state-of-the-art multilinear model. The best architecture exploited the spatial correlation between neighboring electrodes with CNN and benefited from the sequential character of the desired hand trajectory by using LSTMs. Overall, DL increased the average cosine similarity, compared to the multilinear model, by up to 60%, from 0.189 to 0.302 and from 0.157 to 0.249 for the left and right hand, respectively. Significance. This study shows that DL-based models could increase the accuracy of BCI systems in the case of 3D hand translation prediction in a tetraplegic subject.
Nonlinear decay of high-power microwaves into trapped modes in inhomogeneous plasma
Authors: Tancetti A. , Nielsen S.K. , Rasmussen J. , Gusakov E.Z. , Popov A.Yu. , Moseev D. , Stange T. , Senstius M.G. , Killer C. , Vecséi M. , Jensen T. , Zanini M. , Abramovic I. , Stejner M. , Anda G. , Dunai D. , Zoletnik S. , Laqua H.P. , the W7-X Team  
Published: March 2022

Abstract
We present novel experimental evidence of parametric decay instability of microwave beams in the plasma edge of the Wendelstein 7-X stellarator. We propose that the instability is sustained by trapping of only one daughter wave in the non-monotonic density profile measured with high spatial resolution within a stationary magnetic island. The power levels and spectral shapes of the detected microwave signal are reproduced by numerical modelling and a theoretical power threshold is predicted around 300 kW, comparable with observations. We predict a fraction of power drained by daughter waves around 4% in the experiments, potentially increasing above 50% for more hollow edge density profiles. Such absorption levels could significantly reduce the efficiency of the microwave heating and current-drive system in tokamaks and stellarators.
Overwintering fires rising in eastern Siberia
Authors: Xu Wenxuan , Scholten Rebecca C , Hessilt Thomas D , Liu Yongxue , Veraverbeke Sander 
Published: March 2022

Abstract
Overwintering fires are a historically rare phenomenon but may become more prevalent in the warming boreal region. Overwintering fires have been studied to a limited extent in boreal North America; however, their role and contribution to fire regimes in Siberia are still largely unknown. Here, for the first time, we quantified the proportion of overwintering fires and their burned areas in Yakutia, eastern Siberia, using fire, lightning, and infrastructure data. Our results demonstrate that overwintering fires contributed to 3.2 ± 0.6% of the total burned area during 2012–2020 over Yakutia, compared to 31.4 ± 6.8% from lightning ignitions and 51.0 ± 6.9% from anthropogenic ignitions (14.4% of the burned area had unknown cause), but they accounted for 7.5 ± 0.7% of the burned area in the extreme fire season of 2020. In addition, overwintering fires have different spatiotemporal characteristics than lightning and anthropogenic fires, suggesting that overwintering fires need to be incorporated into fire models as a separate fire category when modelling future boreal fire regimes.
Subnational assessment of threats to Indian biodiversity and habitat restoration opportunities
Authors: Chaudhary Abhishek , Mair Louise , Strassburg Bernardo B N , Brooks Thomas M , Menon Vivek , McGowan Philip J K 
Published: March 2022

Abstract
The active involvement of subnational authorities, cities and local governments has been identified as one of the enabling conditions to implement the Convention on Biological Diversity’s Post-2020 Global Biodiversity Framework and progress towards the United Nations’ Sustainable Development Goal 15 (Life on Land). However, there has not been any systematic application of any biodiversity metric at the subnational level to identify where the main responsibilities and opportunities lie within a country. Here, we therefore apply the recently proposed species threat abatement and restoration (STAR) metric for amphibians, birds and terrestrial mammals in 36 states and 666 districts of India, one of 17 megadiverse countries. The STAR metric takes into account the endemicity and the scope and severity of all threats affecting each species’ population hosted by the region and can quantify the potential contribution of threat mitigation and habitat restoration in a particular region towards global biodiversity goals. The larger the STAR metric score, the larger the contribution of a specified area for global species conservation. Out of 97 individual threats affecting species in India, we found that crop production is the major threat, contributing 44% of the total national STAR score followed by biological resource use such as hunting and logging (23%), and residential and commercial development (11%). Just seven out of 36 states and 66 out of 666 districts hosting high numbers of threatened and endemic species contribute 80% to the national STAR score. Importantly, the states and districts with most potential to contribute to threat abatement do not always overlap with those where habitat restoration will yield high benefits. Our analysis demonstrates the applicability and value of the STAR metric to subnational governments for biodiversity conservation elsewhere in the world.
Future PM2.5 emissions from metal production to meet renewable energy demand
Authors: Rathod Sagar D , Bond Tami C , Klimont Zbigniew , Pierce Jeffrey R , Mahowald Natalie , Roy Chaitri , Thompson John , Scott Ryan P , Hoal Karin Olson , Rafaj Peter 
Published: March 2022

Abstract
A shift from fossil fuel to renewable energy is crucial in limiting global temperature increase to 2 °C above preindustrial levels. However, renewable energy technologies, solar photovoltaics, wind turbines, and electric vehicles are metal-intensive, and the mining and smelting processes to obtain the needed metals are emission-intensive. We estimate the future PM2.5 emissions from mining and smelting to meet the metal demand of renewable energy technologies in two climate pathways to be 0.3–0.6 Tg yr−1 in the 2020–2050 period, which are projected to contribute 10%–30% of total anthropogenic primary PM2.5 combustion emissions in many countries. The concentration of mineral reserves in a few regions means the impacts are also regionally concentrated. Rapid decarbonization could lead to a faster reduction of overall anthropogenic PM2.5 emissions but also could create more unevenness in the distributions of emissions relative to where demand occurs. Options to reduce metal-related PM2.5 emissions by over 90% exist and are well understood; introducing policy requiring their installation could avoid emission hotspots.