bluuebunny/crossref_metadata_2025 huggingface dataset:
A ReaxFF molecular dynamics study of insulation paper modification by plasma ROS
Authors: Yin Haojie , Gao Guoqiang , Yang Yan , Liu Kai , Wu Guangning
Published: March 2022

Cold atmospheric-pressure plasma is used widely for treating material surfaces and can be considered for modifying insulation paper (IP) to improve its surface performance. However, the mechanism for interaction between reactive oxygen species (ROS), which are the dominant components of such plasma, and IP is important for setting experimental parameter values but is difficult to observe experimentally. In this paper, reactive force field molecular simulation technology is used to study the mechanism for interaction between ROS (O atoms, OH radicals, and H2O2 molecules) and cellulose, which is the main component of IP. The results show that the ROS can abstract H atoms, and the H2O2 molecules can also abstract hydroxyl groups from a cellulose chain, resulting in changes to the cellulose chain structure, such as reductions of the hydroxyl groups and pyran rings and formations of aldehyde and vinyl groups. The three types of ROS exhibit different reactivities when reacting with the cellulose chain, and the difficulty of breaking different bonds therein also differs, which influences how the chemical groups change the cellulose chain. This study provides basic insight into the mechanism for interaction between ROS and IP at the atomic level as well as offering some guidance for practical experiments.
On the role of preexisting MHD activity for the plasma response to massive deuterium injection
Authors: Wieschollek F. , Hoelzl M. , Nardon E. ,   JOREK Team,   ASDEX Upgrade Team,   EUROfusion MST1 Team
Published: March 2022

As part of a reliable disruption mitigation system (SPI) for ITER, pure deuterium shattered pellet injection (SPI) has been proposed as a way of avoiding hot tail runaway electron generation. It offers the possibility of diluting the plasma and, thereby, cooling it down by a large factor without immediately triggering a thermal quench (TQ). However, the reliability of this and similar SPI approaches could be reduced by preexisting MHD modes, which are usually present during the pre-TQ phase, when the disruption mitigation scheme is being triggered. To address this question, this theoretical study investigates massive deuterium injection into an MHD active ASDEX Upgrade plasma using the non-linear MHD code JOREK. Cases with and without preexisting 2/1 islands are studied. Scans are performed in the preexisting island size, the number of atoms injected, and the relative phase of the injection location with respect to the island. Realistic values of resistivity and heat diffusion anisotropy are considered. This provides insights into the physical mechanisms at play and the relevant time scales involved. Results largely indicate that plasma dilution by deuterium also seems to work reliably in the presence of preexisting MHD activity. Nevertheless, when injecting in phase with the X-point of a large preexisting island, the TQ can occur earlier than without. Altogether, simulations increase confidence in the reliability of plasma dilution by deuterium injection and its applicability to ITER.
Particle-in-cell simulation of vacuum arc breakdown process of tip-to-plate electrode configuration
Authors: Huang Wen-Dong , Geng Jin-Yue , Yan Hao , Liu Yu-Xi , Liu Xu-Hui , Sun Su-Rong , Wang Hai-Xing
Published: March 2022

The breakdown of a vacuum arc under high applied voltage conditions usually occurs on very short time and space scales, and a deep understanding of these processes is essential to extend the application of vacuum arc devices. To study the time and spatial evolution of plasma parameters during vacuum breakdown, a two-dimensional axial-symmetric particle-in-cell code with Monte Carlo collisions is used in the numerical simulation of tip-to-plate electrode configuration. In this simulation, in addition to considering the primary and secondary ionization of copper atoms, the excitation and de-excitation processes of copper atoms are also introduced so that the evolution of the light intensity of the vacuum arc in the different stages of breakdown processes can be obtained by tracking the de-excitation process of the atoms, which can be considered a virtual camera. In this way, the cathode radiance, anode light expansion, arc channel establishment, and arc quenching processes can be visually observed, and the trends are consistent with the images taken by Intensified Charge-Coupled Device (ICCD) and streak cameras reported in the literature. The analysis of the sputtering amount of the anode material due to the impact of the cathode plasma to the anode surface shows that the contribution of atoms, singly, and doubly ionized ions to the sputtering of the anode material varies at different stages of the discharge.
Exchange scattering on ultrafast timescales in a ferromagnetic two-sublattice system
Authors: Leckron Kai , Baral Alexander , Schneider Hans Christian
Published: March 2022

We investigate ultrafast spin dynamics due to exchange, electron–phonon and Elliott–Yafet spin-flip scattering in a model with a simple band structure and ferromagnetically coupled electronic sublattices (or more generally, subsystems). We show that this incoherent model of electronic dynamics leads to sublattice magnetization changes in opposite directions after ultrashort-pulse excitation. This prominent feature on an ultrafast timescale is related to a transfer of energy and angular momentum between the subsystems due to exchange scattering. Our calculations illustrate a possible incoherent mechanism that works in addition to the coherent optically induced spin transfer mechanism.
Plasma thermal transport with a generalized 8-moment distribution function
Authors: Hamilton Jason , Seyler Charles E.
Published: March 2022

Moment equations that model plasma transport require an ansatz distribution function to close the system of equations. The resulting transport is sensitive to the specific closure used, and several options have been proposed in the literature. Two different 8-moment distribution functions can be generalized to form a single-parameter family of distribution functions. The transport coefficients resulting from this generalized distribution function can be expressed in terms of this free parameter. This provides the flexibility of matching the 8-moment model to some validating result at a given magnetization value, such as Braginskii's transport, or the more recent results of Davies et al. [Phys. Plasma, 28, 012305 (2021)]. This process can be thought of as a solution for the 8-moment distribution function that matches the value of a transport coefficient given by a Chapman–Enskog expansion while retaining the improved physical properties, such as finite propagation speeds and time dependence, which belong to the hyperbolic moment models. Since the presented generalized distribution function only has a single free parameter, only a single transport coefficient can be matched at a time. However, this generalization process may be extended to provide multiple free parameters. The focus of this Brief Communication is on the dramatically improved thermal conductivity of the proposed model compared to the two base moment models.
Thermocapillary convection in liquid-in-liquid capillary bridges due to a heating/cooling ring
Authors: Saifi A. H. , Mundhada V. M. , Tripathi M. K.
Published: March 2022

A liquid bridge connecting two solid disks is surrounded by a heating/cooling ring in the presence of another immiscible liquid. The thermocapillary convection and the interface deformation thus generated in a gravitational environment are studied for a range of bridge aspect ratios and ring temperatures using 2D axisymmetric simulations. A stark difference between the heater and cooler cases is observed in their flow and heat transfer patterns. Interfacial velocity and bridge deformation are seen to be more stable when a cooling ring surrounds the liquid bridge. Fluid trajectories inside the bridge show longer paths as the temperature difference between the cooler/heater and the surroundings is raised. Moreover, a cooler lessens the deformation, whereas a heater enhances the deformation of the phase interface. Anomalous results for a heat transfer rate, interface deformation, and circulation patterns are obtained in the heater configuration for larger height to radius ratios.
Structure, electrical, and optical properties of reactively sputter-deposited Ta—Al—N thin films
Authors: Anğay Fırat , Camelio Sophie , Eyidi Dominique , Krause Bärbel , Abadias Gregory
Published: March 2022

We report on the influence of Al content on the structural, electrical, and optical properties of polycrystalline ternary Ta—Al—N thin films. Ta1−xAlxNy thin films with x up to 0.69 and 0.92 ≤ y ≤ 1.22 were deposited on silicon substrates by means of direct current reactive magnetron co-sputtering from elemental Ta and Al targets. The elemental composition, crystal structure, bonding state, and electrical and optical properties of the deposited films were characterized using wavelength-dispersive x-ray spectrometry, x-ray diffraction, x-ray photoelectron spectroscopy, four-point probe electrical resistance, and spectroscopic ellipsometry (SE), respectively. The real part (ɛ1) and imaginary part (ɛ2) of the dielectric constants were derived from the SE data, which were simulated and fitted by using a Drude and Lorentz oscillator models. The Ta1−xAlxNy films are characterized by a compact microstructure, which becomes more columnar with increasing Al content. It is found that the incorporation of Al into TaN lattice results in the stabilization of cubic Ta1−xAlxNy solid solutions up to x = 0.40, while a hexagonal phase is formed for 0.48 ≤ x ≤ 0.69. This structural transition is accompanied by a change in the chemical bonding state, high electrical resistivity (8–10 mΩ cm), and semi-transparent character. Ternary Ta1−xAlxNy alloys with a small amount of Al (x = 0.02 and 0.06) show superior electrical and optical conductivities compared to a binary TaN compound, making them appealing material candidates for UV plasmonic applications.
An investigation of chaotic mixing behavior in a planar microfluidic mixer
Authors: Yuan Shuai , Zhou Mingyong , Peng Tao , Li Qiang , Jiang Fengze
Published: March 2022

Achieving rapid mixing of different liquids in a short distance is important in various biochemical applications. Herein, a novel planar mixer with staggered Z-shaped baffles is proposed. Numerical investigations are carried out to evaluate its mixing ability based on mixing quality and pressure drop when the Reynolds number (Re) varies from 0.1 to 50. The Lyapunov exponent, the Poincaré map, and the vortex visualization are conducted to comprehensively analyze the chaotic state and the mixing mechanism. Results show that the proposed mixer exceeds 0.9 mixing efficiency when 0.1 ≤ Re and Re ≥ 8. As Re ≥ 8, different vortex patterns appear by changing the inlet configuration. The disturbance for fluids induced by a vortex on the mass transfer surface is not only dependent on its intensity but also related to the position of the vortex/vortex leg. The proposed planar mixer, inducing a single vortex or vortex pair with different directions, presents different mixing performance when the Re varies from 8 to 50, from which the approach of the rotating vortex that can mainly improve the mixing quality is found. This well explains the chaotic mixing behavior observed in the planar mixer with Z-shaped baffles, which to date has not been studied before. Furthermore, the micromixer is fabricated, tested, and applied for luminol–peroxide chemiluminescence detection to characterize its performance.
Artificial neural networks modeling of wall pressure spectra beneath turbulent boundary layers
Authors: Dominique J. , Van den Berghe J. , Schram C. , Mendez M. A.
Published: March 2022

We analyze and compare various empirical models of wall pressure spectra beneath turbulent boundary layers and propose an alternative machine learning approach using Artificial Neural Networks (ANNs). The analysis and the training of the ANN are performed on data from experiments and high-fidelity simulations by various authors, covering a wide range of flow conditions. We present a methodology to extract all the turbulent boundary layer parameters required by these models, also considering flows experiencing strong adverse pressure gradients. Moreover, the database is explored to unveil important dependencies within the boundary layer parameters and to propose a possible set of features from which the ANN should predict the wall pressure spectra. The results show that the ANN outperforms traditional models in adverse pressure gradients, and its predictive capabilities generalize better over the range of investigated conditions. The analysis is completed with a deep ensemble approach for quantifying the uncertainties in the model prediction and integrated gradient analysis of the model sensitivity to its inputs. Uncertainties and sensitivities allow for identifying the regions where new training data would be most beneficial to the model's accuracy, thus opening the path toward a self-calibrating modeling approach.
Magnon polarons in spin Seebeck effect of easy axis antiferromagnets
Authors: Liu Huicong , Shen Ka
Published: March 2022

The formation of magnon polarons, quanta of magnetoelastic waves, was found to be able to stimulate an enhancement or suppression in the magnetic field dependence of the spin Seebeck effect when the dispersion curve of the magnon becomes tangential to those of acoustic phonons. In the present work, we systematically analyzed the properties of the magnon spectrum in body-centered cubic easy-axis antiferromagnets with varying strength of exchange interaction and magnetic anisotropy, which allowed us to classify the antiferromagnets according to the number of solutions for the tangential condition between the dispersion curves of magnons and acoustic phonons. The anomaly features were found to occur only in the relatively weak magnetic field regime before spin flop transition. The manifestation of magnon–polaron-induced anomaly on the longitudinal spin Seebeck coefficient was also calculated directly from which a triple-peak feature, never observed or proposed before, was predicted. Our analysis also works for antiferromagnets with other magnetic lattices.
Probing the coalescence of non-Newtonian droplets on a substrate
Authors: Chen Hao , Pan Xiaolong , Nie Qichun , Ma Qianli , Fang Haisheng , Yin Zhouping
Published: March 2022

To better understand the coalescence of droplets, which play critical roles in diverse natural processes and industrial applications, we give attention to the non-Newtonian rheology of liquid drops—in particular, studying the coalescence of two non-Newtonian droplets on a solid surface, with special attention to the effect of the shear thinning behavior. Based on a theoretical power-law model, we show that the height h0 of the liquid bridge connecting two adjacent droplets grows with a power function of time as h0 ∼ tn, where n indicates the power-law exponent. Through numerical simulations, we reveal a self-similar regime during the initial stage of coalescence and propose an accurate prediction for capturing the spatial structure of the flow. Our results also update the effect of the contact angle, which significantly alters the coalescence dynamics.
Impact of superhydrophobic sphere onto a pool covered by oil layer
Authors: Li Han , Chen Han , Li Er-Qiang , Zhang Chun-Yu , Ding Hang
Published: March 2022

We experimentally investigate the impact of a millimetric superhydrophobic sphere on a water pool covered by a thin oil layer, with the aim of seeking the critical conditions for sphere entrapment at the interfaces. The interfacial tension and viscosity of the thin oil layer are found to have a significant effect on the fate of the impacting spheres that are denser than the liquids: sinking or floating. For the oil layer of low viscosity, the impact dynamic is dominated by the capillary force, and the sphere experiences more or less uniform acceleration after the impact, which is similar to a sphere impacting onto a pure water pool. For the oil layer of relatively high viscosity, the viscous dissipation inside the thin oil layer greatly hinders the descending of the sphere, and thus, it is the viscosity of the oil layer that dictates the acceleration process of the spheres at the early stage of impact. At the late stage, the sphere moves very slowly under water (particularly at the onset of sinking), and the competition between the oil–water interfacial tension and buoyancy determines whether the sphere would eventually sink or float. We then conduct the theoretical analysis of the dynamic processes of the impacting sphere and give the theoretical predictions of the respective critical conditions, which agree well with the experimental observations.
Introduction to the Fabrication of Polymers and Polymeric Composites
Authors: Kant Rishi , Chauhan Pankaj Singh , Patel Vinay Kumar , Bhattacharya Shantanu
Published: March 2022

Increasing concern over environmental issues around the world has generated a desperate need for eco-friendly polymer and polymeric composites with specific properties. This need is also driven by polymers and their derivatives finding wide-ranging applications in many diverse industries. These materials possess distinct properties like low overall weight, intrinsic formability, cost-effectiveness, etc., which may invoke properties that can facilitate the replacement of traditional construction materials such as steel and cement. The current chapter describes the organization of the book contents and includes a consolidated view of fabrication methodologies for polymers and polymer composites. Polymers by themselves may lack the required mechanical strength, toughness, creep resistance, thermal stability, etc., and micro/nanofillers and multi-fiber hybridization may be added to them to offset these disadvantages, to improve their performance, and to utilize them in high end applications. The addition of micro-fillers, natural fibers (e.g., bamboo fiber), synthetic fibers, or nanomaterials can be very well achieved by employing a suitable fabrication method. This chapter provides a summary of various fabrication processes, such as photochemical, laser assisted, and additive manufacturing methods. Fabrication protocols for synthesizing polymer composites, such as nanomaterial filled epoxy, reduced graphene oxide modified epoxy, and carbon nano-onions, are also discussed.
Polymer Fabrication Using Photochemical Processes—A Review
Authors: Manoharan Kapil , Bhattacharya Shantanu
Published: March 2022

The past few decades have seen a demand for developing structures of polymers at micro and sub-micro levels having definite sizes and functionality. Photophysics- and photochemistry-based properties of various polymeric materials have been used repeatedly in several research or industry-oriented applications as in microelectronics, tissue engineering, imaging, copying and recording systems, etc. Photochemical reactions promote excitation of a substrate from the ground state to a higher energy state by absorbing ultraviolet, visible, or infrared radiation, causing the substrate to undergo physical and chemical changes. The physical changes can lead to fluorescence and internal conversions, while a chemical change may lead to a rearrangement, elimination, addition, isomerization, or transfer of electrons within a substrate. The abundance of natural light forms and development of specific technologies such as spatial light modulators, photosensitive materials, and other advanced photonic technologies have caused extensive use of this property for the fabrication of polymeric material with increasing resolutions. This chapter will be mainly dealing with a review of the basic photochemical processes used for the fabrication of different polymeric materials in various applications. Recent advancements and future application prospects for the same are also discussed in detail.
Polymer Microfabrication for Biomedical Applications
Authors: Bhatt Geeta , Patel Vinay Kumar , Kant Rishi , Bhattacharya Shantanu
Published: March 2022

Now-a-days, polymer substrates are being increasingly used in biomedical applications, due to their various attractive features like recyclability, higher toughness, easy moldability, and less wear. Most of polymeric substrates also have a good level of biocompatibility to make them available for various biological events such as biofunctionalization and direct analyte processing. Various fabrication techniques like photolithography, soft lithography, hot embossing, porous structure formulation techniques, and microthermoforming are most commonly used for devising polymeric devices. Also, several entities like nanofibers, nanotubes, nanopores, nanofilms, etc. are used directly in biomedical applications. In this respect, several conventional polymers, as well as newly emerging derivatives, are being explored and increasingly utilized. These substrates can be used for various applications like medical diagnostics, drug delivery, therapeutics, and tissue engineering. Considering the totality of these aspects, the present chapter will discuss in detail various microfabrication aspects and applications of polymeric biomedical devices.
Parental UV-B radiation regulates the habitat selection of clonal
Authors: Tie Dan , Guo Yuehan , Zhu Chunrui , Quan Jiaxin , Liu Shiqiang , Zhou Zhe , Chai Yongfu , Yue Ming , Liu Xiao
Published: March 2022

Habitat selection behaviour is an effective strategy adopted by clonal plants in heterogeneous understorey light environments, and it is likely regulated by the parental environment's ultraviolet-B radiation levels (UV-B) due to the photomorphogenesis of UV-B and maternal effects. Here, parental ramets of Duchesnea indica were treated with two UV-B radiation levels [high (UV5 group) and low (UV10 group)], newborn offspring were grown under a heterogeneous light environment (ambient light vs shade habitat), and the growth and DNA methylation variations of parents and offspring were analysed. The results showed that parental UV-B affected not only the growth of the parent but also the offspring. The offspring of different UV-B-radiated parents showed different performances. Although these offspring all displayed a tendency to escape from light environments, such as entering shade habitats earlier, and allocating more biomass under shade (33.06% of control, 42.28% of UV5 and 72.73% of UV10), these were particularly obvious in offspring of the high UV-B parent. Improvements in epigenetic diversity (4.77 of control vs 4.83 of UV10) and total DNA methylation levels (25.94% of control vs 27.15% of UV10) and the inhibition of shade avoidance syndrome (denser growth with shorter stolons and internodes) were only observed in offspring of high UV-B parents. This difference was related to the eustress and stress effects of low and high UV-B, respectively. Overall, the behaviour of D. indica under heterogeneous light conditions was regulated by the parental UV-B exposure. Moreover, certain performance improvements helped offspring pre-regulate growth to cope with future environments and were probably associated with the effects of maternal DNA methylation variations in UV-B-radiated parents.
Engineered nanoparticles enable deep proteomics studies at scale by leveraging tunable nano–bio interactions
Authors: Ferdosi Shadi , Tangeysh Behzad , Brown Tristan R. , Everley Patrick A. , Figa Michael , McLean Matthew , Elgierari Eltaher M. , Zhao Xiaoyan , Garcia Veder J. , Wang Tianyu , Chang Matthew E. K. , Riedesel Kateryna , Chu Jessica , Mahoney Max , Xia Hongwei , O’Brien Evan S. , Stolarczyk Craig , Harris Damian , Platt Theodore L. , Ma Philip , Goldberg Martin , Langer Robert , Flory Mark R. , Benz Ryan , Tao Wei , Cuevas Juan Cruz , Batzoglou Serafim , Blume John E. , Siddiqui Asim , Hornburg Daniel , Farokhzad Omid C.
Published: March 2022

Significance

Deep profiling of the plasma proteome at scale has been a challenge for traditional approaches. We achieve superior performance across the dimensions of precision, depth, and throughput using a panel of surface-functionalized superparamagnetic nanoparticles in comparison to conventional workflows for deep proteomics interrogation. Our automated workflow leverages competitive nanoparticle–protein binding equilibria that quantitatively compress the large dynamic range of proteomes to an accessible scale. Using machine learning, we dissect the contribution of individual physicochemical properties of nanoparticles to the composition of protein coronas. Our results suggest that nanoparticle functionalization can be tailored to protein sets. This work demonstrates the feasibility of deep, precise, unbiased plasma proteomics at a scale compatible with large-scale genomics enabling multiomic studies.
Epstein–Barr virus latency programs dynamically sensitize B cells to ferroptosis
Authors: Burton Eric M. , Voyer Jewel , Gewurz Benjamin E.
Published: March 2022

Significance

Epstein–Barr virus (EBV) contributes to Burkitt lymphoma and post-transplant lymphoproliferative disease (PTLD). EBV-transforming programs activate lipid metabolism to convert B cells into immortalized lymphoblastoid cell lines (LCL), a PTLD model. We found that stages of EBV transformation generate lipid reactive oxygen species (ROS) byproducts to varying degrees, and that a Burkitt-like phase of B cell outgrowth requires lipid ROS detoxification by glutathione peroxidase 4 and its cofactor glutathione. Perturbation of this redox defense in early stages of transformation or in Burkitt cells triggered ferroptosis, a programmed cell death pathway. LCLs were less dependent on this defense, a distinction tied to EBV latency programs. This highlights ferroptosis induction as a potential therapeutic approach for prevention or treatment of certain EBV+ lymphomas.
Chinese EFL learners’ apology strategies
Authors: Pei Xiaoyu , Yang Lianrui , Chen Ying , Wolter Brent
Published: March 2022

This paper presents a multimodal analysis of apologies performed by Chinese EFL learners at two proficiency levels by considering their use of both verbal and nonverbal (i.e., gestures and gaze) strategies. The results showed that both groups used IFID (illocutionary force indicating device, which, in this study, refers to explicit apology strategies such asSorryorForgive me), explanation, and acknowledgment of responsibility strategies frequently, but the high proficiency participants tended to use more diverse IFID sub-strategies. Analysis of gestures also revealed significant between-group differences in the duration and frequency of the use of gestures, with the high proficiency group using more ideographic gestures (gestures which indicate specific meaning or help to express certain meaning, such as emblems, illustrators, and regulators) than their lower proficiency counterparts. Finally, the two groups differed significantly in gaze duration, but not in gaze frequency. These findings suggest that although both groups used nonverbal cues to supplement linguistic strategies of apology, they differed in how they used them. Furthermore, the results highlight the importance of employing a multimodal approach when attempting to gain a more comprehensive understanding of EFL speakers’ use of speech acts.
Environment terms and translation students
Authors: L’Homme Marie-Claude , Marshman Elizabeth , Martín Antonio San
Published: March 2022

This article reports on a pilot study that aims to shed some light on how translation students construe specialized terms. More specifically, we verified their ability to associate environment terms with specific conceptual situations (as understood by Frame Semantics [Fillmore 1976;Fillmore and Baker 2010]). Respondents (27) were asked to complete a questionnaire containing 10 different questions that assessed the association of terms with conceptual situations from different angles. Results show that respondents can associate related terms and link sets of terms to conceptual situations and can make distinctions between the different components of conceptual situations when asked to produce lists of terms or select terms from a predefined list. However, when asked to assess the similarity or difference between specific terms, respondents are less likely to produce the anticipated answer. Our findings suggest that teaching and learning activities inspired by Frame Semantics may be helpful for students to structure their terminological analysis and deal with challenges such as ambiguity and fine semantic distinctions. We hope this can ultimately contribute to helping them make informed, precise and coherent terminological choices.
Dung Kai-cheung’sAtlasin translation
Authors: Zhu Lyujie , Glynn Dominic
Published: March 2022

This article examines issues of translation in Dung Kai-cheung’s董啟章novelDituji: Yige xiangxiang de chengshi de kaoguxue地圖集：一個想像的城市的考古學(Atlas: The Archaeology of an Imaginary City). In the first instance, it provides structural analyses of the constraints shaping the translation of the writer’s work from Chinese to English. It moves on to comment on the imbrication of Hong Kong’s history of translation in the puns and other word games, as well as in the narrative thread. Lastly, it compares different partial English translations of significant passages to (re-)map the linguistic and cultural transfer of this major work of contemporary Hong Kong literature.
Simultaneously enhanced efficiency of eco-friendly structural characterization of the dithienocyclopentacarbazole donor based acceptors with narrow bandgap for high-performance organic solar cells
Authors: Ans Muhammad , Ayub Ahtsham , Alwadai Norah , Rasool Alvina , Zahid Muhammad , Iqbal Javed , Al-Buriahi M S
Published: March 2022

In the present age, researchers are trying to overcome the energy crisis and the global demand for energy by developing organic solar cells (OSCs) of higher efficacy. Herein, we have developed five new acceptor molecules with a dithienocyclopentacarbazole donor unit flanked with different electron-withdrawing end-capped acceptor units, named Z1 ((Z)-2-(2-ethylidene-5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile), Z2 ((Z)-1-(dicyanomethylene)-2-ethylidene-3-oxo-2,3-dihydro-1H-indene-5,6-dicarbonitrile), Z3 ((Z)-2-(5-ethylidene-4-oxo-4,5-dihydro-6H-cyclopenta[b]thiophen-6-ylidene)malononitrile), Z4 ((Z)-2-(5-ethylidene-3-fluoro-4-oxo-4,5-dihydro-6H-cyclopenta[b]thiophen-6-ylidene)malononitrile) and Z5 ((Z)-5-((Z)-5-ethylidene-4-oxo-4,5-dihydro-6H-cyclopenta[b]thiophen-6-ylidene)-3-methyl-2-thioxothiazolidin-4-one) to get greater effectiveness and good activity of OSCs, in order for non-renewable resources to be replaced with cost-effective, better-performing OSCs. B3LYP/6-31G(d,p) was used analytically to explore the maximum absorption wavelength (
λ

max
), reorganization energy (RE), frontier molecular orbital, transition density matrix, open circuit voltage (
V

oc
), density of state, binding energy (
E

b
) and dipole moment of the newly developed molecules. Amongst all the newly designed (Z1–Z5) molecules, the Z2 molecule showed the lowest energy gap (2.04 eV) between highest occupied molecular orbital and lowest unoccupied molecular orbital, maximum λ
max value in the applied phases i.e. gas (680.74 nm) and solvent (737.0 nm) along with the highest dipole moment values in gas (9.85 Debye) and solvent phase (11.0 Debye), lowest values of reorganization energy, and high charge mobilities. In addition, all the newly designed molecules were found to have the potential for better results in contrast to the molecule R (reference molecule).
A neural network model relating extraction current characteristics with optical emission spectra for the purpose of a digital twin of miniaturized ion thrusters
Authors: Zhang Wen-Jie , Zhu Xi-Ming , Wang Yan-Fei , Wang Guo-Xin , Yan Yan , Meng Sheng-Feng , Jia Jun-Wei , Ning Zhong-Xi
Published: March 2022

Miniaturized ion thrusters are one of the most important candidates in the task of drag-free control for space-based gravitational wave detection, the thrust of which can be accurately tuned in principle by in-orbit monitoring and feedback control. This work investigates a neural network model (NNM) that can be used for real-time monitoring of the function that relates the grid voltage and the extraction current of a miniaturized ion thruster using optical emission spectroscopy. This model is developed as a component of an ion thruster’s digital twin. A collisional-radiative model relates the plasma parameters in the discharge chamber of the thruster to the emission spectroscopy; an extraction current model relates the plasma parameters to the function that relates the grid voltage and extraction current. The NNM is trained based on the dataset produced by these models, and is examined by experimental results from a miniaturized ion thruster. It is found that the difference between the thrust predicted by the NNM and the experimental value is less than 6%. Discussions are given on further improvement of the NNM for accurate thrust control in space-based gravitational wave detection in the future.
Enhanced linear dichroism of flattened-edge black phosphorus nanoribbons
Authors: Seixas Leandro
Published: March 2022

Black phosphorus is a material with an intrinsic anisotropy in electronic and optical properties due to its puckered honeycomb lattice. Optical absorption is different for incident light with linear polarization in the armchair and zigzag directions (linear dichroism). These directions are also used in the cuts of materials to create black phosphorus nanoribbons. Edges of nanoribbons usually have small reconstruction effects, with minor electronic effects. Here, we show a reconstruction of the armchair edge that introduces a new valence band, which flattens the puckered lattice and increases the linear dichroism extrinsically in the visible spectrum. This enhancement in linear dichroism is explained by the polarization selection rule, which considers the parity of the wave function to a reflection plane. The flattened-edge reconstruction originates from the inversion of chirality of the P atoms at the edges and significantly alters the entire optical absorption of the material. The flattened edges have potential applications in pseudospintronics, photodetectors and might provide new functionalities in optoelectronic and photonic devices.
Experimental characterization and modelling of the resistive wall mode response in a reversed field pinch
Authors: Saad E A , Brunsell P R
Published: March 2022

Model-based control algorithms have potential advantages for resistive wall mode (RWM) feedback control. In this study, a physics model of the RWM response to externally applied perturbation fields is validated against experiments in a reversed field pinch (RFP). The experimental characterization of the RWM plasma response is performed in the EXTRAP T2R device by the excitation of nonaxisymmetric perturbation magnetic fields utilizing an external array of saddle coils for RWM control. The modelling and experimental validation is carried out with an extended sensor array, resolving a wider spectrum of RWM compared to earlier studies, covering the relevant poloidal

m
=
1

and toroidal

−
32
<
n
<
32

modes for this high aspect ratio RFP device. In addition to the nonresonant unstable modes, which are the primary target of RWM feedback control, this spectrum also includes a wide range of resonant modes. The validated resistive magnetohydrodynamics (MHD) model includes the passive stabilization effect on these modes from intrinsic plasma rotation. The inclusion of resistivity and plasma rotation in the present model provides a substantially better agreement between modelled and experimental growth rates than that observed in earlier studies using the ideal MHD model. The present model provides a realistic description of the plasma response for both nonresonant and resonant modes, which is both relatively simple and compatible with the computing capabilities and latency limitations encountered in practical implementations of model-based control algorithms.
Simulation and modeling of radio-frequency atmospheric pressure plasmas in the non-neutral regime
Authors: Klich Maximilian , Wilczek Sebastian , Donkó Zoltán , Brinkmann Ralf Peter
Published: March 2022

Radio-frequency-driven atmospheric pressure plasma jets (RF APPJs) play an essential role in many technological applications. This work studies the characteristics of these discharges in the so-called non-neutral regime where the conventional structure of a quasi-neutral bulk and an electron depleted sheath does not develop, and the electrons are instead organized in a drift-soliton-like structure that never reaches quasi-neutrality. A hybrid particle-in-cell/Monte Carlo collisions (PIC/MCC) simulation is set up, which combines a fully kinetic electron model via the PIC/MCC algorithm with a drift-diffusion model for the ions. In addition, an analytical model for the electron dynamics is formulated. The formation of the soliton-like structure and the connection between the soliton and the electron dynamics are investigated. The location of the electron group follows a drift equation, while the spatial shape can be described by Poisson–Boltzmann equilibrium in a co-moving frame. A stability analysis is conducted using the Lyapunov method and a linear stability analysis. A comparison of the numerical simulation with the analytical models yields a good agreement.
High torque density magnetorheological brake with multipole dual disc construction
Authors: Shiao Yaojung , Kantipudi Mahendra Babu
Published: March 2022

This paper presents a magnetorheological (MR) brake with the intent of overcoming the problems of limited torque density and low manufacturability that conventional MR brakes come across. Firstly, the conceptual design of the proposed MR brake was finalized. High torque density was achieved by using the combined effect of the dual disc-type construction and multipole concept. High manufacturability was attained with a simple and lightweight mechanical construction. It was created with the major components, namely magnetically permeable stator cases, rotor discs, magnetic cores, winding coils, and MR fluid. The computer aided design (CAD) model and analytical models were also developed to study the performance of the proposed brake. Then, the dimensions of the brake were optimized through electromagnetic simulations. Further, the brake performance was simulated using a three-dimensional electromagnetic model. Finally, a prototype of the optimized MR brake was fabricated, and its performance was experimentally validated. It is clear from the computer simulations and experimental test results, that the proposed MR brake has achieved the objective. The maximum torque was 16.5 Nm, and the torque density of 79.3 Nm dm−3 was significantly higher than that of conventional MR brakes. This brake also exhibited a fairly rapid response with a response rate of 90 ms.
Influence of conditions of liquid dosing on water droplet spreading
Authors: Laga E Yu
Published: March 2022

The work presents the experimental studies of the influence of surface roughness on the dynamic characteristics of distilled water droplet spreading. As solid surfaces, copper samples treated with abrasive materials (average grain size of 10–100 μm) and aluminum samples polished to a mirror finish were used. The advancing dynamic contact angles obtained using DSA technique were found. The effect of the droplet formation rate and surface roughness on the characteristics of water droplet spreading, in particular, dynamic contact angle, was analyzed.
The heat transfer dynamics during dry patch formation in heated liquid layer
Authors: Gigola T G , Cheverda V V
Published: March 2022

In this present paper an experimental study of a dry patch formation of the water layer on the sapphire plate is presented. With help of IR-camera the heat transfer processes are studied and visualised in water liquid layer. These results will be used for the heat transfer solution inside sapphire plate. The first of this research is to determine the temperature distribution on the upper part of sapphire glass to solve heat transfer equation for full sapphire glass.
Investigation of the flight of liquid microdroplets over the contact line in a horizontal liquid film heated from below
Authors: Kirichenko E O , Kirichenko D P , Zaitsev D V
Published: March 2022

When a liquid layer is heated from the substrate, a structured array of levitating microdroplets can be formed near to the surface of the liquid. When a dry spot is formed on the substrate through the liquid layer, the droplets can move under the action of gravity towards the dry spot so that propagation of microdroplets from a wetted to a dry substrate area is accompanied by a substantial change in the droplet levitation height above the contact line. It was found that with an increase in the diameter of a microdroplet, the maximum height of the trajectory, and the flight distance of the drop, decrease.
Numerical modeling of interaction of water molecule and fullerene C60
Authors: Khilchuk M D , Tarasov E A
Published: March 2022

In this paper, the main subject of research is the interaction of nanostructures and water molecules. The method of molecular dynamics is used, which calculates the trajectory of a water molecule inside fullerene C60. The forces acting in the system are determined through the potential energy of the interaction of particles. The Lennard-Jones interaction potential is used. The trajectories of the movement of the water molecule for different initial conditions are obtained, the change in the speed of its movement is estimated, and the size of the movement area is estimated.
Hardware design of the generic rear transition module for the global trigger system of the ATLAS phase II upgrade
Authors: Yin W. , Tang S. , Bonini F. , Begel M. , Benoit M. , Matakias D. , Zhivun E. , Xu H. , Chen H.
Published: March 2022

The High-Luminosity Large Hadron Collider is expected to start operations in the middle of 2027, to deliver more than ten times the integrated luminosity of the Large Hadron Collider Runs 1–3 combined (up to 4000 fb−1). Meeting these requirements poses significant challenges to the hardware design of the trigger and data acquisition system. Global trigger is a new subsystem in the ATLAS phase-II upgrade, which will bring event filter-like capability to the level-0 trigger system. A common hardware platform in Advanced Telecommunications Computing Architecture form factor named Global Common Module is proposed to be configured as processor nodes in the global trigger. To mitigate the risk and simplify the Global Common Module hardware design, a Generic Rear Transition Module is being developed. The Generic Rear Transition Module, which has been implemented with a Xilinx Versal Prime Field Programmable Gate Array and sufficient multi-gigabit transceivers, cannot only achieve system control and communication with the Front-End Link eXchange, but also provide additional processing or readout capacity.
Setup of Compton polarimeters for measuring entangled annihilation photons
Authors: Abdurashitov D. , Baranov A. , Borisenko D. , Guber F. , Ivashkin A. , Morozov S. , Musin S. , Strizhak A. , Tkachev I. , Volkov V. , Zhuikov B.
Published: March 2022

An experimental setup for studying the Compton scattering of
annihilation photons in various (entangled and decoherent) quantum
states is presented. Two entangled γ-quanta with an energy
of 511 keV and mutually orthogonal polarizations are produced by
positron-electron annihilation in a thin aluminum plate and are
emitted in opposite directions. To measure both photons, the setup
provides two equivalent arms of Compton polarimeters. A Compton
polarimeter consists of a plastic scintillation scatterer and an
array of NaI(Tl) detectors for measuring photons deflected at an
angle of 90°. The intermediate scatterer of the GAGG
scintillator with SiPM readout is inserted into one of the arms to
create a tagged decoherence process prior to the measurement of
annihilation photons in polarimeters. The performance of Compton
scatterers and NaI(Tl) counters is discussed. The polarization
modulation factor and the analyzing power of Compton polarimeters
are evaluated from the angular distributions of scattered
gammas. The Compton scattering of photons in entangled and
decoherent states is compared reliably for the first time.
Performance of Soil Nailing for Slope Stabilization-A Review
Authors: Bathini Divya Jyothi , Ramya Krishna V
Published: March 2022

A landslide is a geological event involving a wide range of ground motions that leads to the collapse of soil slope. The stabilization of these soil slopes is done by constructing retaining walls to withstand lateral soil pressure. These retaining walls are costly as well as it is difficult to construct as they require wide excavation for the base or bottom slab. One of the many new solutions to slope stabilization is the soil nailing built by strengthening the steep slope by driving reinforcement into the soil. In this study, a review of the origin and mechanism of soil nailing, the construction process of soil nailed retaining walls were discussed. The failure pattern of soil nails is an important factor to be noticed which influence the stability of soil slope was discussed. Numerical studies were given, which are used to determine the adverse effect of orientation and inclination of nails on the stability of soil nailed walls. A couple of case studies were discussed to evaluate the significance of soil nailing on the stability of the slope and to retain the vertical cut. A Laboratory study was considered to estimate the effect of nail inclination and different nail arrangements on settlement of soil slope. A sequential literature review investigates the application, advantages and disadvantages of soil nailing. This study shall help in understanding the various applications of soil nailing in the civil engineering sector.
Effect of GGBS on Strength Characteristics and Stability of Pond Ash Mixed Soil Embankment
Authors: Rajak T K , Mishra A , Yadu L K
Published: March 2022

The increased usage of coal by thermal power plants results in enormous volumes of pond ash. Ground Granulated Blast Furnace Slag (GGBS) is produced in huge quantity in iron industries and is mostly utilised in the cement industry. Despite the fact that these industrial by-products have a wide range of applications, it is still conceivable to investigate the alternate mode for batch usage. The present study explores the effectiveness of GGBS in modifying the strength characteristics of a soil-pond ash mix. Pond ash was mixed with soil at 10%, 15%, 20%, and 25%, and strength behaviour were determined by analysing compaction characteristics, Unconfined Compressive Strength (UCS), bearing ratio behaviour, and shear strength parameters. The effect of GGBS addition in various amounts on the strength properties of pond ash-soil mix was also observed at various curing periods. Stability analysis was also conducted using limit equilibrium based GEOSLOPE software to evaluate the Factor of Safety (F) and stability of stabilized soil embankment. It was found from the test results that the addition of GGBS to the pond ash-soil mix improved the strength behaviours. With the inclusion of GGBS, the curing period was extended, which resulted in a substantial improvement in strength properties. Substantial improvement in factor of safety and stability of embankment was also observed by adding GGBS in pond ash-soil mix. Outcome of present study demonstrates an alternative approach for effective and safe utilization of GGBS and pond ash at optimum proportions.