bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced studies for probabilistic optimal power flow in active distribution networks: A scientometric review
Authors: Ullah Zia , Wang Shoarong , Wu Guoan , Hasanien Hany M. , Jabbar M. Waqas , Qazi Hasan Saeed , Tostado‐Véliz Marcos , Turky Rania A. , Elkadeem Mohamed R.
Published: July 2022

In the active distribution networks (ADNs), the emerging trend of high penetration of sustainable energy sources such as wind turbines, photovoltaics, and the forthcoming integration of energy storage devices and additional dynamic loads like plug‐in‐electric vehicles (PEVs) influences to change the nature of electric distribution networks. Consequently, it deteriorates power quality and reliability in terms of unacceptable voltage rise‐drop, harmonic distortion, voltage unbalance, and excessive power loss. In this context of transition into the active distribution network, the probabilistic optimal power flow (P‐OPF) in the ADN is considered an important tool that helps the distribution grid operators for defining the optimal settings of the system's control variables. However, the optimal solution of P‐OPF becomes highly complex while considering the multiple variables, time‐varying characteristics and operational uncertainties associated with sustainable resources, consumer behaviour and electricity market prices.

This review aims at promoting the research and discussion of P‐OPF studies in the context of ADNs characteristics and challenges. First, we perform a data‐driven and visualized scientometric analysis of 1988 quality documents retrieved from the Scopus during the last ten years using VOSviewer software. Second, an in‐depth investigation of the recent and emerging techniques for solving the P‐OPF problem is presented. Third, a set of recommendations and highlights of future challenges for P‐OPF in ADNs are offered. The review findings showed high interest among the scientific community in sustainable energy source integration, given the recent rise in publications and citations. Also, there is still a lack of innovative optimization techniques that can adequately handle the current issues associated with P‐OPF and objectives with fair computational efficiency and accuracy. Finally, this paper offers a guide for P‐OPF researchers to navigate the recent studies considering the sustainable sources, spot the new research frontiers, and identify the most impactful countries and publishers.
Research on a prediction model for gas insulation performance based on Pareto optimisation
Authors: You Tianpeng , Dong Xuzhu , Zhou Wenjun , Zheng Yu , Lei Hongyu , Ren Shubo , Li Han , Hou Hua
Published: July 2022

Predicting the insulation performance of SF6 substitute gases through gas molecular structures has been a popular topic worldwide. The difficulty is that the relationships between the molecular structure and the gas insulation strength, global warming potential and boiling temperature are not clear, and general linear methods cannot be used to effectively extract the key factors. Based on published molecular structure parameters, the grey correlation method is used to extract the factors that affect the gas dielectric strength, global warming potential and boiling temperature in a dynamic (non‐linear) approach. Further, to predict the dielectric strength, global warming potential and boiling temperature of gases, a linear regression method and the factors with high correlations are used as independent variables. Through the Pareto optimal solution, the dielectric strength is set as the target, the global warming potential and boiling temperature are set as the constraints, and the ranges of the molecular structure parameters of the SF6 substitute gas are obtained. This research study provides an important reference regarding the SF6 substitute gas analysis and provides a research foundation for the design and synthesis of new environmentally friendly gases used in power equipment.
Polarimetric SAR image classification using binary coding‐based polarimetric‐morphological features
Authors: Imani Maryam
Published: July 2022

Polarimetric synthetic aperture radar (POLSAR) systems provide high resolution images containing polarimetric information. So, they have high capability in land cover classification. In this work, a binary coding‐based polarimetric‐morphological (BCPM) feature extraction is proposed for POLSAR image classification. At first, a set of polarimetric features is proposed. Then, a new morphological framework is introduced for contextual feature extraction from the POLSAR cube. The coherence matrix is composed from diagonal and non‐diagonal elements with different information. These elements are analysed separately in the proposed method. Moreover, the amplitude and phase components of the non‐diagonal elements are individually analysed using morphological filters by reconstruction. Finally, a binary coding‐based polarimetric‐spatial feature reduction, which uses the first order statistics, is proposed for feature transformation. The experiments on three real POLSAR images and a synthetic dataset show the superior performance of BCPM compared to several classification methods.
Synthesis of echogenic liposomes for sonoporation
Authors: Park DongHee , Jung Hyon Chel , Park Juhyun , Bae Seoku , Shin UnChul , Kim Suhng Wook , Kim Chul Woo , Lee Yong Heum , Seo Jongbum
Published: July 2022

Ultrasound contrast agents (UCAs), which are groups of engineered microbubbles, have been recently studied for drug delivery applications, since the cavitation of bubbles can increase the temporary permeability of nearby cells. However, the internal volume of UCAs is generally filled with gas, hence loading drug molecules into UCAs is limited. In this study, an echogenic liposome with a liquid and gas core is proposed as an alternative carrier of genetic material for ultrasound‐mediated drug delivery. The structure of the synthesized echogenic liposome was analysed via transmission electron microscopy and confocal microscopy with fluorescent labels. The protection of siRNA by the echogenic liposomes was also verified by exposure to RNase. The results indicate that at least 10% of the total siRNA used in the experiment was successfully protected by the proposed echogenic liposome. Additionally, the release of siRNA from the liposomes could be successfully achieved with 1 W/cm2 ultrasound sonication at 1 MHz; parameters low enough to be used in generic ultrasound therapeutic systems. Although further studies to clarify the responses to incident ultrasound fields and to quantitatively analyse the internal liquid volume for drug loading are required, the proposed echogenic liposome has great potential for ultrasound‐mediated gene delivery.
A temperature independent hybrid AWG device based on silica/pentafluorostyrene‐glycidylmethacrylate‐fluoroethylmethacrylate terpolymer overclad
Authors: Kang Dong‐Soo , Yang Soo‐Yeon , Park Jong‐Jin
Published: July 2022

The terpolymer (PFS–GMA–TFEMA) was prepared and coated on silica waveguide for polymeric optical overclad. In our study, athermal characteristics were realised by adjusting the coefficient of negative thermal expansion of the synthesised terpolymer overclad, and the positive thermo‐optic coefficient of the silica thin film. The measured values were −1.11 × 10–4 /K and 0.79 × 10–5 /K (dn/dT). The thermal properties according to the temperature change indicated that the wavelength had shifted by about 0.15 nm from 20 to 90°C, with little change over 50°C. When the temperature increased, the wavelength shift of the silica/terpolymer hybrid arrayed waveguide grating was −0.002 nm/°C, compared to the 0.01 nm/°C of silica arrayed waveguide grating. Terpolymer overclad arrayed waveguide grating showed a centre wavelength loss of 5.334 dB, loss uniformity of 0.864 dB, a polarisation dependent loss of 0.162 dB, and a non‐adjacent crosstalk of −31.67 dB.
Expertenaustausch zum Einsatz von kontinuierlichem Glukosemonitoring (CGM) im Diabetesmanagement: Eine aktuelle Bestandsaufnahme und Blick in die Zukunft
Authors: Thomas Andreas , Haak Thomas , Tombek Astrid , Kulzer Bernhard , Ehrmann Dominic , Kordonouri Olga , Kroeger Jens , Schubert-Olesen Oliver , Kolassa Ralf , Siegmund Thorsten , Haller Nicola , Heinemann Lutz
Published: July 2022

CGM mit Darstellung der aktuellen Glukosewerte (rtCGM) ist aktuell einer der wichtigsten diagnostischen Optionen in der Diabetologie. Es ermöglicht eine umfangreiche und unmittelbare Unterstützung und Erleichterung des Diabetesmanagements, besonders wenn eine Insulintherapie angewendet wird. Weiterhin stellt rtCGM den notwendigen Systempartner für die Steuerung der automatisierten Insulinabgabe in AID-Systemen dar. In Verbindung mit Smart-Pens unterstützt ein rtCGM die korrekte Durchführung des Insulinmanagements und erinnert an Bolusinjektionen.

RtCGM-Daten sind heute das Fundament des personalisierten Datenmanagements und Alltagscoachings und stellen die Basis der Digitalisierung und telemedizinischen Intervention dar. Die Möglichkeit der interoperablen Nutzung ist aus therapeutischer Sicht eine zentrale Eigenschaft eines rtCGMs und kann zur Erweiterung der Indikationen, unabhängig von Diabetestyp oder Therapieform führen. Dies könnte auch den vorübergehenden oder intermittierenden Einsatz bei Menschen mit Typ-2-Diabetes ohne Insulinbehandlung betreffen. Kürzlich veröffentlichte internationale Leitlinien, z.B. der Amerikanischen Gesellschaft für klinische Endokrinologie (AACE) fordern auf der Basis umfangreicher Evidenz, dass die Glukosemessung mit einem rtCGM für alle Menschen mit Diabetes nutzbar und verfügbar sein sollte. Bereits in der Phase gestörter Glukosetoleranz kann ein rtCGM-System als Alltagscoaching oder Biofeedback bei Einbettung in ein Gesamtbehandlungskonzept unterstützen, mit dem Ziel aktiver und fundierter Handlungen des Anwenders im Diabetesalltag.

Die Vielfalt der Nutzungsoptionen und die immer schnelleren technischen Innovationszyklen von rtCGM-Systemen wurden mit Blick auf aktuelle Anforderungen und die notwendigen Strukturanpassungen des Gesundheitssystems von einer rtCGM-erfahrenen Expertengruppe diskutiert. Ziel war es, konkrete Lücken in der Versorgungsstruktur sowie potenzielle Handlungsfelder in der Diabetologie zu identifizierten und mögliche Indikationserweiterungen für den Einsatz von rtCGM darzustellen. Dieses, sowie die Erkenntnisse und Schlussfolgerungen der Diskussionen werden in diesem Artikel dargestellt.
Humour and sarcasm: expressions of global warming on Twitter
Authors: Eslen-Ziya Hande
Published: July 2022

The increasing popularity of Twitter as a medium for sharing and debating scientific information brings forth questions about the type of narratives emerging around environmental/climate change and global warming. This article maps the landscape of narratives of how Twitter is used to communicate about environmental issues in Turkey. It displays how these actors can play a crucial role in constructing and/or de-constructing such crisis. I show how Twitter users in Turkey, use such medium to strengthen their own and the public’s awareness on global warming or to deny all together create a counter narrative and how certain frames that promote scepticism about environmental change are broadly disseminated by using certain emotional context. The analyses of the 1295 tweets collected using a random week sample displayed users who are sceptical about the Turkish government taking a more active stance toward climate change whereas the users supporting the government in general where more preoccupied with hoax arguments that in return may compromise trust in scientific authorities. The analysis combines thematic analysis of tweets and coding. I conclude the paper by conversing the significance of studying Twitter as a communicative platform that provides rich information displaying the existing dynamics.
Etching silicon nanopillars to emit telecom photons
Authors: Patrick Chris
Published: July 2022

Wet-etching technique followed by ion implantation produces high-density, nanopillar arrays hosting telecom photon emitters for quantum applications.
Confining arc plasmas with alternating magnetic fields
Authors: Thompson Avery
Published: July 2022

A dynamic field produces a more constricted and precise plasma arc than a steady magnetic field.
Preferential sublimation along threading dislocations in InGaN/GaN single quantum well for improved photoluminescence
Authors: Damilano B. , Vézian S. , Chauvat M. P. , Ruterana P. , Amador-Mendez N. , Collin S. , Tchernycheva M. , Valvin P. , Gil B.
Published: July 2022

InGaN/GaN single quantum wells were grown by molecular beam epitaxy on the silicon substrate onto thin AlN and GaN buffer layers. The InGaN/GaN structure is porosified using a combination of SixNy nanomasking and sublimation and compared with a non-porous reference. The photoluminescence efficiency at room temperature of the porosified sample is improved by a factor reaching 40 compared with the reference sample. Plan-view and cross-sectional transmission electron microscopy images reveal that the remaining material is free of dislocation cores. The regions around dislocations are, thus, preferentially sublimated. This explains the strong photoluminescence improvement of nanoporous InGaN/GaN samples.
High resolution atomic force microscopy with an active piezoelectric microcantilever
Authors: Mahmoodi Nasrabadi Hazhir , Mahdavi Mohammad , Soleymaniha Mohammadreza , Moheimani S. O. Reza
Published: July 2022

Active microcantilevers with on-chip sensing and actuation provide significant advantages in tapping mode Atomic Force Microscopy (AFM). Collocated transduction allows for effective manipulation of cantilever dynamics through feedback control, enabling higher scan rates. However, the adjacency of the sensing and actuation electrodes is known to result in a high level of feedthrough, leading to a low imaging resolution. Readout circuit noise further deteriorates the imaging precision. Here, we investigate the noise sources that affect AFM microcantilevers with collocated aluminum nitride (AlN) actuator–sensor pairs. We reported these cantilevers in earlier work and demonstrated that they display a very low level of feedthrough between the actuation and sensing electrodes. We present a high signal-to-noise ratio (SNR) sensing method that enables us to demonstrate high-resolution AFM on a calibration grating with nm-step silicon carbide (SiC) terraces. Measuring the Lorentzian response of the cantilever’s Brownian motion with the on-chip active sensor at resonance enables us to calibrate the dynamic stiffness at the first fundamental resonance mode, without utilizing an optical sensor.
Defect levels in CsPbCl3 single crystals determined by thermally stimulated current spectroscopy
Authors: Peters John A. , Liu Zhifu , De Siena Michael C. , Kanatzidis Mercouri G. , Wessels Bruce W.
Published: July 2022

Thermally stimulated current (TSC) spectroscopy was used to characterize electronic trap states in the perovskite CsPbCl3 bulk single crystals which are promising for gamma ray detection. The TSC spectra indicate the presence of multiple traps over the temperature range from 80 K to above room temperature. The possible analytical defects identified were VCs and VCl vacancies and Pbi interstitials that have concentrations of the order of 1011−1016 cm−3 and capture cross sections of ∼10−18 cm2. A comparison of crystals grown from different ingots reveals that the concentration of defects in the crystal with an improved growth procedure is about one to four orders of magnitude less than those of a crystal from an earlier growth process. A further reduction and elimination of trap states within the perovskite ingot should lead to crystals with improved mobilities, carrier lifetimes, and detector response characteristics.
Modeling of a vertical tunneling transistor based on Gr-hBN-
χ
3 borophene heterostructure
Authors: Abbasi Reza , Faez Rahim , Horri Ashkan , Moravvej-Farshi Mohammad Kazem
Published: July 2022

We present a computational study on the electrical behavior of the field-effect transistor based on vertical graphene-hBN-χ3 borophene heterostructure and vertical graphene nanoribbon-hBN-χ3 borophene nanoribbon heterostructure. We use nonequilibrium the Green function formalism along with an atomistic tight-binding (TB) model. The TB parameters are calculated by fitting tight-binding band structure and first-principle results. Also, electrical characteristics of the device, such as ION/IOFF ratio, subthreshold swing, and intrinsic gate-delay time, are investigated. We show that the increase of the hBN layer number decreases subthreshold swing and degrades the intrinsic gate-delay time. The device allows current modulation 177 at room temperature for a 1.2 V gate-source bias voltage.
Volumetric tri-modal imaging with combined photoacoustic, ultrasound, and shear wave elastography
Authors: Zheng Emily , Zhang Huijuan , Hu Wentao , Doyley Marvin M. , Xia Jun
Published: July 2022

Photoacoustic imaging is a hybrid imaging approach that combines the advantages of optical and ultrasonic imaging in one modality. However, for comprehensive tissue characterization, optical contrast alone is not always sufficient. In this study, we combined photoacoustic imaging with high-resolution ultrasound and shear wave elastography. The multi-modal system can calculate optical absorption, acoustic reflection, and stiffness volumetrically. We constructed a multi-modal phantom with contrast for each imaging modality to test the system’s performance. Experimental results indicate that the system successfully visualizes the embedded structures. We envision that the system will lead to more comprehensive tissue characterization for cancer screening and diagnosis.
An in-depth investigation of the microstructural evolution and dynamic properties of Zr77Rh23 metallic liquids and glasses: A molecular dynamics simulation study
Authors: Celtek Murat
Published: July 2022

The microstructural evolutions and dynamic properties of the Zr77Rh23 alloy during the rapid cooling process have been studied by molecular dynamics (MD) simulations using tight-binding (TB) potential. The total pair distribution functions [or structure factors, S(q)], g(r), calculated at different temperatures are in good agreement with the ab initio MD (AIMD) simulation (or experimental) results. The splitting in the second peak of all g(r) is notable for the formation and development of a medium-range order (MRO) in the Zr77Rh23 system. Moreover, the total number of atoms determined from TB-MD simulations at 300 K is also consistent with the number of atoms of the three shells for the Bergman-type MRO cluster and AIMD simulation results. By analyzing the structure of the system with methods such as the Honeycutt–Andersen index, Voronoi tessellation, and bond-angle distribution, it has been shown that the icosahedron short-range order (SRO) increases upon cooling. The dominant short-range structure in Zr77Rh23 metallic glass is found to consist mostly of perfect and distorted icosahedral clusters. The findings show that, for all temperatures, Zr atoms have greater mobility than Rh atoms. The critical temperature Tc estimated from fitting the mode-coupling theory equation is ∼993 K. A dynamic crossover is observed at temperatures around Tc. The present findings contribute to understanding the nature of the atomic local structures of the Zr77Rh23 alloy during the cooling process and the formation of SRO/MROs in metallic glasses.
Numerical simulations of polygonal particles settling within non-Newtonian fluids
Authors: Jiao Kaituo , Han Dongxu , Li Jingfa , Yu Bo
Published: July 2022

The settling of circular and polygonal particles within non-Newtonian fluids is investigated by combining the lattice Boltzmann method (LBM) and the discrete element method (DEM). The immersed moving boundary (IMB) scheme with good numerical stability is adopted to couple LBM and DEM. To efficiently calculate the solid coverage ratio in IMB, a novel method is developed, which simply involves judging whether the square is fully occupied by the particle and subdividing the square crossed by the fluid–solid boundary. After validations, the drafting–kissing–tumbling dynamics of two particles settling in the Newtonian and power-law fluids are studied first. It shows that the shear-thickening fluid has a longer kissing duration than the Newtonian and shear-thinning fluids. The kissing duration of squared particles (0.29–0.41 s) is shorter than triangular particles (0.32–0.84 s) and much shorter than circular particles (0.61–0.98 s). Then, the settling of multiple and multi-shape particles in a closed cavity is analyzed. The disturbed area of kinematic viscosity induced by particle motion in the shear-thinning fluid is 21.0–22.5 cm2, significantly larger than in the shear-thickening fluid (10.1–10.8 cm2). Circular particles have a larger disturbed area than the polygonal particles due to the larger settling velocity. Moreover, compared with the Newtonian and shear-thinning fluids, the shear-thickening fluid has a smaller vertical length of particle cluster, meaning a positive influence on the agglomeration of particles.
High-resolution CH stretch spectroscopy of jet-cooled cyclopentyl radical: First insights into equilibrium structure, out-of-plane puckering, and IVR dynamics
Authors: Kortyna Andrew , Reber Melanie A. R. , Nesbitt David J.
Published: July 2022

First, high-resolution sub-Doppler infrared spectroscopic results for cyclopentyl radical (C5H9) are reported on the α-CH stretch fundamental with suppression of spectral congestion achieved by adiabatic cooling to Trot ≈ 19(4) K in a slit jet expansion. Surprisingly, cyclopentyl radical exhibits a rotationally assignable infrared spectrum, despite 3N − 6 = 36 vibrational modes and an upper vibrational state density (ρ ≈ 40–90 #/cm−1) in the critical regime (ρ ≈ 100 #/cm−1) necessary for onset of intramolecular vibrational relaxation (IVR) dynamics. Such high-resolution data for cyclopentyl radical permit detailed fits to a rigid-rotor asymmetric top Hamiltonian, initial structural information for ground and vibrationally excited states, and opportunities for detailed comparison with theoretical predictions. Specifically, high level ab initio calculations at the coupled-cluster singles, doubles, and perturbative triples (CCSD(T))/ANO0, 1 level are used to calculate an out-of-plane bending potential, which reveals a C2 symmetry double minimum 1D energy surface over a C2v transition state. The inversion barrier [Vbarrier ≈ 3.7(1) kcal/mol] is much larger than the effective moment of inertia for out-of-plane bending, resulting in localization of the cyclopentyl wavefunction near its C2 symmetry equilibrium geometry and tunneling splittings for the ground state too small (<1 MHz) to be resolved under sub-Doppler slit jet conditions. The persistence of fully resolved high-resolution infrared spectroscopy for such large cyclic polyatomic radicals at high vibrational state densities suggests a “deceleration” of IVR for a cycloalkane ring topology, much as low frequency torsion/methyl rotation degrees of freedom have demonstrated a corresponding “acceleration” of IVR processes in linear hydrocarbons.
Liquid–liquid transition kinetics in D-mannitol
Authors: Cao Chengrong , Tang Wei , Perepezko John H.
Published: July 2022

The kinetics of the first order liquid–liquid transition (LLT) in a single-component liquid D-mannitol have been examined in detail by the high rate of flash differential scanning calorimetry measurements. By controlling the annealing temperature, the phase X formation from the supercooled liquid is distinguished by either a nucleation-growth or a spinodal-decomposition type of LLT. In the measured time–temperature-transformation curve the portion covering the nucleation-growth type of LLT can be well fitted with a classical nucleation theory analysis.
Shallow trap mediated temperature-dependent exciton and Mn2+ photoluminescence in CsPbCl3:Mn2+ nanocrystals
Authors: Guo Heng , Zhu Yizhi , Chen Jinping , Xie Xiaoyu , Jiang Qingsong , Xu Chunxiang , Cui Qiannan , Shi Zengliang
Published: July 2022

As an effective means to endow lead halide perovskite nanocrystals (NCs) with new properties, ion doping has been widely applied. Transition metal Mn-doped CsPbCl3 is of particular interest, as the Mn doping introduces new emission bands, improves photoluminescence quantum yield (PLQY), and even enhances stability. However, it is still insufficient to catch insight of the energy transfer process and luminescence characteristics of these high defect tolerance NCs doped with Mn ion. Here, we systematically studied the energy transfer from exciton to Mn2+ ions in Mn-doped CsPbCl3 NCs by variable temperature steady-state fluorescence spectra and time-resolved spectra. The abnormal attenuation behavior of the exciton and Mn2+ with the change of temperature was observed, from which we predict the existence of shallow traps near the conduction band and these shallow traps will affect the luminescence properties by influencing the energy transfer process. We show a simple physical model invoking only shallow trap states that uniquely describe the temperature-dependent energy transfer between the exciton and the Mn2+ ion. The thermometric performance (30–290 K) was studied in terms of relative thermal sensitivity, in which the calculated relative sensitivity range is ∼0.12%–1% K−1.
Theoretical study of threshold intensity dependence on gas pressure in the breakdown of helium by CO2 laser radiation: Influence of preionization mechanism
Authors: Gamal Yosr E. E.-D. , Metwally Ehab. S. , Nassef O. Aied
Published: July 2022

An electron cascade model adapted to provide a thorough understanding of the physical mechanisms involved in CO2 laser-induced helium plasma is presented. The model combines a time-dependent calculation of the electron energy distribution with rate equations, describing how the population of excited states changes [Y. E. E.-D. Gamal and G. Abdellatif, Appl. Phys. B 117(1), 103 (2014)]. It encountered the possible elastic and inelastic electron collisional processes that enhance the electrons' growth, leading to gas breakdown. The analysis explores the experimental threshold intensity dependency on gas pressure [J. J. Camacho et al., Spectrochim. Acta, Part B 66(1), 57 (2011)]. The measurements are carried out using 9.621 μm over pressure in the range from 12.0 to 87.0 kPa. Since multiphoton ionization is improbable, ionization proceeds via the inverse bremsstrahlung absorption. In this experiment, the ignition of this process is initiated by the experimentally assumed pre-breakdown approach. No experimental estimation was given for the initial electron density. The electron diffusion and the loss of electron energy through elastic collisions have no contribution to this experiment. The calculations of the threshold intensity are performed to determine the initial electron density. The model's validity is assured by the reasonable agreement between the calculated thresholds, and the measured ones are only achieved at a specific initial electron value for each gas pressure. Over pressure exceeding 30.0 kPa, the agreement was reasonable in the presence of recombination losses. The threshold intensity is controlled by the initial electron density for lower pressures. The analysis showed how the gain and loss of electrons control the breakdown threshold for helium concerning the determined initial electron density for the tested pressures.
Photoionization of helium atom embedded in classical non-ideal plasma at high non-relativistic photon energies
Authors: Das Netai , Das Biswajit , Ghoshal Arijit
Published: July 2022

The effects of the non-ideality (NI) of classical plasmas on the photoionization of helium atoms at high non-relativistic photon energies are investigated within the framework of the dipole approximation. Screened interaction in non-ideal plasmas is represented by an effective potential, deduced from a solution of Bogolyubov's hierarchy equations on discarding the effects of quantum degeneracy. A highly correlated wave function consisting of 715 terms for the ground state of helium has been used to evaluate the dipole matrix element. Changes in the asymptotic cross sections of single, double, and total photoionizations due to varying NI of plasmas have been investigated in detail. Particular emphasis is made to study the changes in the asymptotic ratio of the double-to-single photoionization cross section caused by the variation of non-ideality parameter in a wide range. It is found that increasing plasma NI makes the feasibility of occurrence of double photoionization to broaden.
Orientational wetting and dynamical correlations toward glass transition on the surface of imidazolium-based ionic liquids
Authors: Liu Min , Liu Huashan , Peng Hailong
Published: July 2022

Surface induces many fascinating physical phenomena, such as dynamic acceleration, surface anchoring, and orientational wetting, and, thus, is of great interest to study. Here, we report classic molecular dynamics simulations on the free-standing surface of imidazolium-based ionic liquids (ILs) [C4mim][PF6] and [C10mim][PF6]. On [C10mim][PF6] surface, a significant orientational wetting is observed, with the wetting strength showing a diverging tendency. Depth of the wetting was captured from the density and orientational order profile by a static length, which remarkably increases below the temperature Tstat upon cooling down. The dynamical correlation length that measures the distance of surface-dynamics acceleration into the bulk was characterized via the spatial-dependent mobility. The translational correlation exhibits a similar drastic increment at Tstat, while the rotational correlation drastically increases at a lower temperature Trot. We connect these results to the dynamics in bulk liquids, by finding Tstat and Trot that correspond to the onset temperatures where the liquids become cooperative for translational and rotational relaxation, respectively. This signifies the importance of collective dynamics in the bulk on the orientational wetting and surface dynamics in the ILs.
Pressure-annealed high-density amorphous ice made from vitrified water droplets: A systematic calorimetry study on water’s second glass transition
Authors: Bachler Johannes , Giebelmann Johannes , Amann-Winkel Katrin , Loerting Thomas
Published: July 2022

In previous work, water’s second glass transition was investigated based on an amorphous sample made from crystalline ice [Amann-Winkel et al., Proc. Natl. Acad. Sci. U. S. A. 110, 17720 (2013)]. In the present work, we investigate water’s second glass transition based on the genuine glassy state of high-density water as prepared from micron-sized liquid water droplets, avoiding crystallinity at all stages. All the calorimetric features of water’s second glass transition observed in the previous work are also observed here on the genuine glassy samples. This suggests that the glass transition indeed thermodynamically links amorphous ices continuously with deeply supercooled water. We proceed to extend the earlier study by investigating the effect of preparation history on the calorimetric glass transition temperature. The best samples prepared here feature both a lower glass transition temperature Tg,2 and a higher polyamorphic transition temperature Tons, thereby extending the range of thermal stability in which the deeply supercooled liquid can be observed by about 4 K. Just before the polyamorphic transition, we observe a spike-like increase of heat capacity that we interpret in terms of nucleation of low-density water. Without this spike, the width of water’s second glass transition is 15 K, and the Δcp amounts to 3 ± 1 J K−1 mol−1, making the case for the high-density liquid being a strong liquid. We suggest that samples annealed at 1.9 GPa to 175 K and decompressed at 140 K to ≥0.10 GPa are free from such nuclei and represent the most ideal high-density amorphous glasses.
Non-dimensional analysis of an unsteady flow in a magnetorheological damper
Authors: Shou Mengjie , Xie Lei , Li Rui , Liao Changrong
Published: July 2022

Theoretical modeling is often applied to study magnetorheological dampers (MRDs) with dimensional and non-dimensional analyses. In contrast to dimensional models, non-dimensional analyses can eliminate the influence of dimensionality and reduce the number of redundant parameters to simplify theoretical modeling and provide more universal applicability. However, most previous non-dimensional analyses have been based on quasi-steady flows that cannot reflect the transient response of an MRD because of the key assumption that the fluid velocity changes instantaneously. This study presents an investigation of the transient response of an MRD using a non-dimensional analysis approach based on an unsteady model. We focus on the step response of the MRD with a step excitation of the piston speed, while the magnetic field is kept constant. For a comprehensive analysis, a set of dimensionless parameters are defined, including a non-dimensional coordinate, a non-dimensional time parameter, the Bingham number, a non-dimensional pre-yield thickness, a damping coefficient, and a hydraulic amplification ratio. The relationships between these dimensionless numbers are analyzed. An unusual “concave area” is found in the velocity profile instead of a simple rigid flow during the transient process under a magnetic field. However, when the non-dimensional time is 0.4, the delayed concave area disappears, and the rigid area fluid velocity reaches 98% of its stable value.
Developmental constraints enforce altruism and avert the tragedy of the commons in a social microbe
Authors: Belcher Laurence J. , Madgwick Philip G. , Kuwana Satoshi , Stewart Balint , Thompson Christopher R. L. , Wolf Jason B.
Published: July 2022

Organisms often cooperate through the production of freely available public goods. This can greatly benefit the group but is vulnerable to the “tragedy of the commons” if individuals lack the motivation to make the necessary investment into public goods production. Relatedness to groupmates can motivate individual investment because group success ultimately benefits their genes’ own self-interests. However, systems often lack mechanisms that can reliably ensure that relatedness is high enough to promote cooperation. Consequently, groups face a persistent threat from the tragedy unless they have a mechanism to enforce investment when relatedness fails to provide adequate motivation. To understand the real threat posed by the tragedy and whether groups can avert its impact, we determine how the social amoebaDictyostelium discoideumresponds as relatedness decreases to levels that should induce the tragedy. We find that, while investment in public goods declines as overall within-group relatedness declines, groups avert the expected catastrophic collapse of the commons by continuing to invest, even when relatedness should be too low to incentivize any contribution. We show that this is due to a developmental buffering system that generates enforcement because insufficient cooperation perturbs the balance of a negative feedback system controlling multicellular development. This developmental constraint enforces investment under the conditions expected to be most tragic, allowing groups to avert a collapse in cooperation. These results help explain how mechanisms that suppress selfishness and enforce cooperation can arise inadvertently as a by-product of constraints imposed by selection on different traits.
Recovery patterns, cross-linguistic transfer effects and modulating factors in the rehabilitation of bilingual
aphasia
Authors: Hu Mengmeng
Published: July 2022

This article firstly introduces an emerging field of bilingual aphasia and discusses the theoretical framework and
the significance of bilingual aphasia research. It then provides a review of existing research, focusing on recovery patterns,
cross-linguistic transfer effects, and modulating factors in the rehabilitation of bilingual aphasia. It concludes with
identification of areas for future research to advance knowledge in bilingual aphasia.
Analysis of unitarity in conformal quantum gravity
Authors: Kubo Jisuke , Kuntz Jeffrey
Published: July 2022

We perform a canonical quantization of Weyl’s conformal gravity by means of the covariant operator formalism and investigate the unitarity of the resulting quantum theory. After reducing the originally fourth-order theory to second-order in time derivatives via the introduction of an auxiliary tensor field, we identify the full Fock space of quantum states under a Becchi–Rouet–Stora–Tyutin (BRST) construction that includes Faddeev–Popov ghost fields corresponding to Weyl transformations. This second-order formulation allows the formal tools of operator-based quantum field theory to be applied to quadratic gravity for the first time. Using the Kugo–Ojima quartet mechanism, we identify the physical subspace of quantum states and find that the subspace containing the transverse spin-2 states comes equipped with an indefinite inner product metric and a one-particle Hamiltonian that possesses only a single eigenstate. We construct the Lehmann–Symanzik–Zimmermann (LSZ) reduction formula for the S-matrix in this spin-2 subspace and find that unitarity is violated in scattering events. The explicit way in which this violation occurs represents a new view on the ghost-problem in quadratic theories of quantum gravity.
Resistivity dependence on nanostructure formation in picosecond ablation of silicon and SERS-based sensing applications
Authors: Kumar Kanaka Ravi , Banerjee Dipanjan , Mangababu A , Prasad Goud R Sai , Pathak A P , Soma Venugopal Rao , Nageswara Rao S V S
Published: July 2022

We report on the influence of resistivity in picosecond (ps) laser ablation of silicon (Si) leading to the formation of diverse surface micro- and nanostructures. Subsequently, we investigated their potential in sensing applications based on the surface enhanced Raman scattering (SERS) technique. The varying resistivity (ρ
1: 1–10 Ω cm, ρ
2: 0.01–0.02 Ω cm, ρ
3: 0.001–0.005 Ω cm) Si wafers were subjected to cross patterned ps laser ablation in ambient air. Ladder-like microstructures embedded with numerous nano growths were formed on low resistivity Si (ρ
3) while similar micro- and nanostructures were observed on higher resistivity Si (ρ
2 < ρ
1). The structures were non-plasmonic and anti-reflecting in nature with an optical reflectance of <6% over a broad range of wavelengths (350–1200 nm). Non-plasmonic Si microstructures were subsequently transformed to plasmonic by means of deposition of a thin layer of gold (Au). Additionally, the effect of annealing on the evolution of nanostructures was also investigated. We employed these hybrid substrates for the trace detection of an explosive molecule, ammonium nitrate, and dye, malachite green. Our detailed SERS studies have demonstrated a superior enhancement in the trace detection of analytes for low resistivity Si substrate. However, the annealed hybrid substrates have demonstrated further improvement in the SERS signal (by at least one order of magnitude). These detailed SERS investigations provide us a proof of the sensitivity of different resistivity Si nano/microstructures.
Two-dimensional simulation of microsecond-timescale underwater electrical explosion of a copper wire
Authors: Shi Huantong , Li Tuan , Hu Yujia , Li Xingwen , Wu Jian , Chen Li , Qiu Aici
Published: July 2022

Underwater electrical wire explosion (UEWE) is an efficient source of underwater shock waves (SWs). In order to efficiently simulate the interaction between the UEWE SW and structures, a coupled model that includes the electric circuit, the exploding wire and the surrounding water is established based on user-subroutines provided by the commercial explicit dynamics software ANSYS AUTODYN. The modeling starts from room temperature by using the tabular wide-range metal equation of state (EOS) and conductivity data. Experimental validation is performed with copper wires exploded by a μs-timescale pulsed discharge. The numerical results show satisfactory consistency with experiments in terms of the current and voltage waveforms, the wire expansion trajectory, the evolution of SW front, the interaction between SW and electrodes and the SW pressure profiles. The main discrepancy lies in the SW amplitude that is ∼20% higher in the calculation and the possible reasons are discussed in detail. Based on this approach and with proper modifications to the metal EOS and conductivity data, the interaction between UEWE SWs and structures can be efficiently modeled in 2D and 3D for practical applications.
Cavity-mediated drag in double-layer graphene
Authors: Escudero F , Ardenghi J S
Published: July 2022

We study the frictional drag between two graphene layers placed inside a cavity. We show that the drag has two contributions: the well-known Coulomb drag, and a novel photon-mediated drag. The latter arises from a cavity-mediated interaction in which the backscattering is not suppressed and the screening is relatively weak. As a result, the photon-mediated drag resistivity in the Fermi-liquid regime acquires corrections to the usual quadratic temperature dependence, has a slow decay as the interlayer separation d increases, and depends on the carrier density n as

ρ
D

∼
1

/

n
2

. Thus, whereas for small d and n the Coulomb drag dominates, as these parameters increase the drag transitions to a purely photon-mediated drag. The onset of this transition depends on the electromagnetic field enhancement inside the cavity.
Prototype-guided bi-level adversarial domain adaptation network for intelligent fault diagnosis of rotating machinery under various working conditions
Authors: Kuang Jiachen , Xu Guanghua , Zhang Sicong , Han Chengcheng , Wu Qingqiang , Wei Fan
Published: July 2022

Recently, deep learning (DL) models have proved to be effective in intelligent fault diagnosis of rotating machinery. However, due to diverse working conditions, the existence of domain shift is pervasive, which limits the popularization and application of traditional DL models. To address the above issue, an end-to-end prototype-guided bi-level adversarial domain adaptation (DA) network, which consists of a feature learner, health state classifier, source prototype learning module, domain-level discriminator and several class-level discriminators, is proposed for intelligent cross-domain fault diagnosis (CDFD). On the one hand, the feature learner and the domain-level discriminator compete with each other for a marginal-level DA. On the other hand, the feature learner and these class-level discriminators jointly play a minimax game for a conditional-level DA. Moreover, the prototypes learned by the prototype learning module are integrated into the bi-level adversarial DA, which facilitates the diagnostic knowledge transfer across domains. Extensive CDFD tasks on bearing and gearbox platforms are carried out for method validation. The results indicate that the proposed method is feasible and promising to promote intelligent fault diagnosis performance in engineering applications.
Effect on the measurement for gear involute profile caused by the error of probe position
Authors: Ling Ming , Ling Siying , Li Xiaoyan , Shi Zhaoyao , Wang Liding
Published: July 2022

Gear involute artefact (GIA) is a kind of measurement standard used to calibrate involute measuring instruments. To measure the profile deviation of GIA more accurately, the effect on the measurement of a gear involute profile caused by the error of the probe position is considered, the value of profile deviations would be affected and the measurement curve of profile deviations would be compressed or stretched along the roll path length, caused by the error of the probe position. Moreover, about 60% of the measurement errors are concentrated within the involute root of roll path length ρ= 0–5 mm. Based on the above research, an adjustment method for the probe position with a double roller-guide involute measuring instrument is proposed and measurement experiments are carried out using probes with probe radius ro
= 0.5 mm, 1.5 mm and 2.5 mm. As the error of probe position e > 0, the curve of profile deviations at the root of the involute is biased towards the body. As the error of probe position e < 0, the profile deviation curve at the root of the involute except for the vicinity of base circle is biased towards the body, while the profile deviation curve near the base circle is biased out of the body caused by the interference of the transition surface, and the measurement curve of profile deviations at the root of the involute is significantly compressed. These errors decrease as the probe radius increases and the error of the probe position decreases. The difference of profile slope deviations and profile form deviations measured by the three probes after adjustment is 0.11 μm and 0.04 μm respectively, which indicates the feasibility of the probe adjustment method described above. The research supports the machining and measurement of a high-precision gear involute artefact.
A portable flow tube homogenizer for aerosol mixing in the sub-micrometre and lower micrometre particle size range
Authors: Horender Stefan , Giordano Andrea , Auderset Kevin , Vasilatou Konstantina
Published: July 2022

A portable and light-weight aerosol homogenizer has been designed and validated experimentally. The design relies on large-scale primary standards for particle number and mass concentration previously developed for metrology applications, but the dimensions have been scaled down to produce a versatile and user-friendly apparatus for everyday applications in aerosol sciences. The homogenizer is a 0.8 m long cylinder made of steel with an inner diameter of 50 mm, equipped with three inlets for primary aerosols and up to four outlets for sampling homogenized aerosol mixtures. Mixing is achieved by three turbulent air jets. The aerosol spatial homogeneity in the sampling zone was within ±1% and ±4% for 2 and 5 µm polystyrene (PS) particles, respectively. The possibility to supply and control independently aerosol flows with pressure-sensitive generators and the short equilibration time (<1 min) have also been demonstrated. The homogenizer allows for mixing various aerosol components, such as soot, inorganic species and mineral dust particles, to generate ambient-like aerosols in the laboratory or industrially manufactured particles such as PS spheres as model aerosols. We believe that it could have applications in applied aerosol research, health-related studies, and instrument calibration.
The simplest erasing substitution
Authors: Della Corte Alessandro , Isola Stefano , Piergallini Riccardo
Published: July 2022

In this work, we begin the study of a new class of dynamical systems determined by interval maps generated by the symbolic action of erasing substitution rules. We do this by discussing in some detail the geometric, analytical, dynamical and arithmetic properties of a particular example, which has the virtue of being arguably the simplest and that at the same time produces interesting properties and new challenging problems.