bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics affecting the attitude and approach of physicians to breaking bad news: Uncertain medical situations
Authors: Yurdakul Eray Serdar , Coskun Zuhal Yapici , Sari Oktay , Coskun Ali Kagan
Published: April 2024

Breaking bad news is a difficult but unavoidable responsibility of physicians. It constitutes a set of stressfull duties, which become more critical during uncertain medical situations such as the COVID-19 pandemic. The purpose of the current study; To determine the factors that affect physicians’ attitudes and approaches in giving bad news about, life-threatening medical conditions. All staff working in the COVID-19 wards as physicians were invited to complete a standardized questionnaire evaluating the descriptive properties and attitude and approach to breaking bad news in this cross-sectional study. A total of 120 physicians were included in the study. An approximately equal number of physicians working in internal medicine and surgical branches were included in the study (p = 0.540). Internal medicine specialists encountered breaking bad news more commonly than surgeons (p = 0.002). Only 14.2% of them stated that they “always” felt competent. Approximately, 68.3% (n = 82) of the physicians did not receive any kind of training on breaking bad news. More than half of the physicians stated feeling anxious about breaking bad news, particularly when announcing death. Announcement of death due to COVID-19 (5.8%) followed announcing fatal diseases (13.3%) and limb loss with function loss (8.3%). The COVID-19 pandemic revealed the physicians’ need for education on “breaking bad news.” Physicians with a shorter work experience had a higher rate of receiving undergraduate education about breaking bad news than those with more work experience. As the length of service increased, there was a significant increase in the rate of receiving education regarding breaking bad news after graduation (p = 0.037). Additionally, it helped to convey the optimal approach in extraordinary and uncertain medical situations. Our study findings support this statement.The most common reason for breaking bad news is the announcement of death, which should be conveyed to the patient’s relatives in accordance with communication principles, taking into account their current situation. This approach can effectively reduce the anxiety experienced by the physician breaking the news and mitigate reactions from the patient’s relatives such as refusal and incomprehension in the face of the patient’s loss.
A systematic review of Stimulated Recall (SR) in educational research from 2012 to 2022
Authors: Zhai Xuesong , Chu Xiaoyan , Wang Minjuan , Tsai Chin-Chung , Liang Jyh-Chong , Spector Jonathan Michael
Published: April 2024

Stimulated Recall (SR) has long been used in educational settings as an approach of retrospection. However, with the fast growing of digital learning and advanced technologies in educational settings over the past decade, the extent to which stimulated recall has been effectively implemented by researchers remains minimal. This systematic review reveals that SR has been primarily employed to probe the patterns of participants’ thinking, to examine the effects of instructional strategies, and to promote metacognitive level. Notably, SR video stimuli have advanced, and the sources of stimuli have become more diverse, including the incorporation of physiological data. Additionally, researchers have applied various strategies, such as flexible intervals and questioning techniques, in SR interviews. Furthermore, this article discusses the relationships between different SR research items, including stimuli and learning contexts. The review and analysis also demonstrate that stimulated recall may be further enhanced by integrating multiple data sources, applying intelligent algorithms, and incorporating conversational agents enabled by generative artificial intelligence such as ChatGPT. This article provides a comprehensive analysis of SR studies in the realm of education and proposes a promising avenue for researchers to proactively apply stimulated recall in investigating educational issues in the digital era.
Nonvolatile behavior of resistive switching memory in Ag/WOx/TiOy/ITO device based on WOx/TiOy heterojunction
Authors: Elshekh Hosameldeen , Wang Hongyan , Yang Chuan , Zhu Shouhui
Published: April 2024

Two-terminal structure memristors are the most promising electronic devices that could play a significant role in artificial intelligence applications of the next generation and the post-Moore era. In this work, we fabricated the memristive device by depositing a heterojunction WOx/TiOy functional layer onto an indium tin oxide substrate using magnetron sputtering. The Ag/WOx/TiOy/ITO device exhibits improved memory behavior of bipolar resistive switching (RS) nonvolatile compared to TiOy-based single-layer memristors, enabling it to meet high-density information storage requirements. Moreover, our device exhibited the coexistence of the negative differential resistance effect and the behavior of the RS memory. Through a comprehensive analysis of conductivity on the curve of current–voltage (I–V), a physical model based on the mechanism of space charge-limited current, ohmic conduction, and Schottky emission was suggested to explain the behavior device RS memory. This study's findings demonstrate that including a heterojunction bilayer WOx/TiOy as a functional layer can significantly improve the performance of memristive devices. This advancement expands the potential application of ferroelectric metallic oxide heterojunctions within the field of memristors.
Cu/MgO-based resistive random access memory for neuromorphic applications
Authors: Hu Gao , Yu Zhendi , Qu Hao , Yuan Youhong , Li Dengfeng , Zhu Mingmin , Guo Jinming , Xia Chen , Wang Xunying , Wang Baoyuan , Ma Guokun , Wang Hao , Dong Wenjing
Published: April 2024

Resistive Random Access Memory (ReRAM) is considered to be a suitable candidate for future memories due to its low operating voltage, fast access speed, and the potential to be scaled down to nanometer range for ultra-high-density storage. In addition, its ability to retain multi-level resistance states makes it suitable for neuromorphic computing applications. In this paper, we report the resistive switching performance of Cu/MgO/Pt ReRAM. Repetitive resistive switching transitions with low switching voltages (around 1 V), 102 storage windows, and multi-level memory capabilities have been obtained. Biological synaptic plasticity behavior, such as long-duration potentiation/depression and paired-pulse facilitation, has been realized by the Cu/MgO/Pt ReRAM. The simulation of convolutional neural network for handwritten digit recognition is carried out to evaluate its potential application in neuromorphic systems. Finally, the conduction mechanism of the device is studied, and a resistive switching model based on Cu conducting filaments is proposed according to the dependence of I–V results on temperature and electrode size as well as the element distribution in the device. These findings indicate the potential of Cu/MgO/Pt device as high-performance nonvolatile memories and its utilization in future computer systems and neuromorphic computing.
Viscosities of inhomogeneous systems from generalized entropy scaling
Authors: Bursik Benjamin , Stierle Rolf , Schlaich Alexander , Rehner Philipp , Gross Joachim
Published: April 2024

This study extends entropy scaling to inhomogeneous fluids by using the classical density functional theory together with a new viscosity reference that takes into account the influence of solid–fluid interactions on the fluid viscosity. The density functional theory uses a Helmholtz energy functional based on the perturbed-chain statistical associating fluid theory; the local residual entropy per particle is determined from the temperature derivative of the Helmholtz energy functional in combination with an appropriate weighted density profile. The weighted density calculation requires a single transferable parameter, which is adjusted to a reference molecular dynamics simulation. In particular, local viscosity values for fluids under nanoconfinement near solid–fluid interfaces are predicted using the same entropy scaling parameters as for homogeneous fluids. We validate the model by comparing viscosity and velocity profiles with results from non-equilibrium molecular dynamics simulations of a Couette flow in a slit pore. Good agreement is found between the entropy scaling model and the non-equilibrium molecular dynamics results for both the viscosity and velocity profiles of the Lennard–Jones truncated and shifted fluid. The proposed model extrapolates well to systems with different temperatures, fluid densities, and shear forces as well as to systems with different wetting behaviors. These results demonstrate that entropy scaling can be generalized to inhomogeneous fluids using an appropriate combination of residual entropy profile and viscosity reference.
Tunneling field-effect transistors with two-dimensional BiN as the channel semiconductor
Authors: Yan Saichao , Wang Kang , Guo Zhixin , Wu Yu-Ning , Chen Shiyou
Published: April 2024

The lack of suitable channel semiconductor materials has been a limiting factor in the development of tunneling field-effect transistor (TFET) architectures due to the stringent criteria of both air stability and excellent gate-tunable electronic properties. Here, we report the performance limits of sub-10-nm double-gated monolayer (ML) BiN TFETs by utilizing first-principles quantum-transport simulations. We find that ML BiN possesses an indirect bandgap of 0.8 eV and effective masses of 0.24m0 and 2.24m0 for electrons and holes, respectively. The n-type BiN TFETs exhibit better performance than the p-type ones, and the on-state current can well satisfy the requirements of the International Roadmap for Devices and Systems for both high-performance and low-power standards. Notably, we find that the BiN TFETs exhibit distinguished gate controllability with an ultra-low subthreshold swing below 60 mV/decade even with a small gate length of 6 nm, which is superior to the existing field-effect transistors, such as black phosphorus TFETs, GeSe TFETs, and BiN metal–oxide–semiconductor field-effect transistors. Furthermore, the BiN TFETs are endowed with the potential to realize high switching speed and low-power consumption applications because of their extremely short delay time and ultra-low power-delay product. Our results reveal that the ML BiN is a highly competitive channel material for the next-generation TFETs.
Hydrodynamic performance of vertical cylindrical wave energy absorbers in front of a vertical wall
Authors: Li Ai-jun , Liu Yong , Wang Xin-yu
Published: April 2024

This paper studies the hydrodynamic performance of vertical cylindrical absorbers in front of a vertical wall. All the absorbers are independent of each other and restricted to only the heave motion. Based on a linear potential flow theory, an analytical solution is developed for the problems of wave diffraction and radiation by absorbers. In the solving procedure, the hydrodynamic problem is first transformed into an equivalent problem in an open water domain using the image principle. The number of absorbers in the equivalent problem is twice that in the real problem, and the plane layout is symmetric about the original vertical wall. The velocity potential of the fluid domain is obtained using the method of variable separation, and the unknown expansion coefficients in the velocity potential are determined by the matched boundary conditions. The heave excitation force, added mass, radiation damping, motion response, and energy capture width of the absorbers are calculated. Case studies are presented to show the effects of the wall reflection and hydrodynamic interaction on the energy extraction performance of the wave energy converter (WEC) system. Subsequently, the WEC performance under the action of irregular waves is analyzed by considering an incident wave spectrum, and the mean annual absorbed power of the device is estimated by considering the wave data statistics at the actual sites. The results indicate that when the wave motion resonates with the absorber motion, the energy extraction performance of the absorbers is significantly improved. The performance of the absorbers can be effectively improved when the structures are close to the antinodes of a standing wave field. By designing a reasonable plane layout, the hydrodynamic interaction can play a constructive role in the performance of the WEC system.
Enhancing power capacity and performance of wide-drift-channel transit-time oscillators for long-pulse high-power microwave generation
Authors: Xu Weili , Ling Junpu , He Juntao , Song Lili , Zeng Fanbo , Pi Mingyao , He Yufang , Song Hao , Ding Bin
Published: April 2024

This paper addresses the challenge of extending the pulse duration of high-power microwave (HPM) sources, a critical focus in HPM technology. Transit-time oscillators (TTOs) typically modulate electron beams by forming standing waves through the cutoff of the TM01 mode in the modulation cavity. This study proposes enhancing the power capacity of TTOs by widening the drift channel. To enhance modulation capability without compromising power capacity, front and rear reflectors are strategically introduced. In particle-in-cell simulations, the device exhibits an output power of 1.65 GW at a frequency of 12.6 GHz, with an efficiency of 33.6%. The saturation time for the output microwave is 30 ns, and the maximum internal electric field strength is 860 kV/cm. The presented TTO, with design improvements, offers a promising solution for applications requiring prolonged pulse durations in high-power microwave sources.
Propagation characteristics of obliquely incident THz waves in inhomogeneous fully ionized dusty plasma using the scattering matrix method
Authors: Su Ruiming , Zhao Yuexing , Ma Jinping , Ji Lingzhao , Song Yan , Shi Yuren
Published: April 2024

The scattering matrix method is applied to investigate the propagation characteristics of obliquely incident terahertz (THz) waves in inhomogeneous fully ionized dusty plasma. The propagation coefficients of THz waves are analyzed with different physical parameters in the case of parabolic electron density distribution. The results show that the transmissivity of lower frequency THz waves have a noticeable variation with the change of physical parameters. However, the transmissivity values can rapidly approach 1 in higher frequency band. We notice that there is a critical value fc≈0.045 THz. When f>fc, the transmissivity increases as the dust particles density and radius increase. However, it is somewhat opposite when f<fc. Significantly, the THz waves exhibit a greater propensity for penetrating fully ionized dusty plasma compared with the weakly ionized dusty plasma. To a certain degree, the investigation results provide new ideas for addressing the issue of “blackout”.
Viscoelasticity of suspension of red blood cells under oscillatory shear flow
Authors: Takeishi Naoki , Rosti Marco Edoardo , Yokoyama Naoto , Brandt Luca
Published: April 2024

We present a numerical analysis of the rheology of a suspension of red blood cells (RBCs) for different volume fractions in a wall-bounded, effectively inertialess, small amplitude oscillatory shear (SAOS) flow for a wide range of applied frequencies. The RBCs are modeled as biconcave capsules, whose membrane is an isotropic and hyperelastic material following the Skalak constitutive law. The frequency-dependent viscoelasticity in the bulk suspension is quantified by the complex viscosity, defined by the amplitude of the particle shear stress and the phase difference between the stress and shear. SAOS flow basically impedes the deformation of individual RBCs as well as the magnitude of fluid-membrane interactions, resulting in a lower specific viscosity and first and second normal stress differences than in steady shear flow. Although it is known that the RBC deformation alone is sufficient to give rise to shear-thinning, our results show that the complex viscosity weakly depends on the frequency-modulated deformations or orientations of individual RBCs but rather depends on combinations of the frequency-dependent amplitude and phase difference. The effect of the viscosity ratio between the cytoplasm and plasma and of the capillary number is also assessed.
Fractal study on the nonlinear seepage mechanism during low-permeability coal water injection
Authors: Yang He , Liu Zhen , Yu Zehan , Zhu Muyao , Dong Shuai , Sun Shuyang , Zhang Fuchang , Wu Fengting , Yan Zihao
Published: April 2024

In the initial stage of coal seam water injection, due to the high density and low permeability of coal bodies, an obvious startup pressure gradient is observed in relation to water seepage; this phenomenon leads to low-velocity nonlinear seepage. In this paper, we study the nonlinear seepage law and the main influencing parameters of the water injection process. First, based on the startup pressure gradient, the nonlinear seepage equation, and the fractal theory, we formulated a nonlinear seepage model of coal seam water injection that considered the fractal characteristics of a complex coal structure. Subsequently, we carried out coal seam water injection and gas radial seepage experiments under a high overburden pressure, obtaining the startup pressure gradient according to the seepage characteristics and the changes of dynamic parameters. Then, the dynamic parameters of water injection, the structural parameters of the coal samples, the physical parameters, and the fractal dimension were substituted into the theoretical model to obtain the theoretically calculated value. Finally, through comparative analysis of theoretical and experimental startup pressure gradient calculation results, it is found that with the increase in the overburden pressure, the permeability of coal and the connectivity effect are reduced, while the fracture tortuosity and the startup pressure gradient increase. Moreover, coal seam permeability does not seem to be the single decisive factor for the nonlinear startup pressure gradient.
Experimental and numerical investigation of the aerodynamic characteristics of high-performance vehicle configurations under yaw conditions
Authors: Rijns Steven , Teschner Tom-Robin , Blackburn Kim , Proenca Anderson Ramos , Brighton James
Published: April 2024

This study investigates the impact of yaw conditions on the aerodynamic performance and flow field of three high-performance vehicle model configurations by means of wind tunnel testing and unsteady Reynolds-Averaged Navier–Stokes-based computational fluid dynamics simulations. While yaw effects on automotive vehicles have been explored, the effects on far more complex flow fields of high-performance vehicles remain insufficiently researched. This paper reveals that yaw conditions have a significant negative influence both downforce and drag performance. Spoiler and rear wing devices enhance downforce but increase the vehicle's sensitivity to yaw. Furthermore, yaw conditions significantly alter vortex structures and local flow velocities, affecting downstream flow behavior. Surface pressure measurements on the slant confirm these findings and highlight notable yaw effects and upstream effects from spoiler and rear wing devices. Wake analyses through total pressure measurements show that yaw induces a substantial deviation from straight-line wake characteristics, which become dominated by an inboard rotating vehicle body vortex. Overall, this research enhances the understanding of the effects of yaw conditions on high-performance vehicle aerodynamics and provides valuable data for future vehicle aerodynamics research in real-world operating conditions.
Tailoring stress relaxation for dopant-free ZnO thin films with high thermoelectric power factor
Authors: Pham Anh Tuan Thanh , Truong Dai Cao , Phan Trang Thuy Thi , Nguyen Nhi Hoang , Choi Taekjib , Le Thu Bao Nguyen , Lai Hoa Thi , Van Le Ngoc , Ung Thuy Dieu Thi , Tran Vinh Cao , Snyder Gerald Jeffrey , Phan Thang Bach
Published: April 2024

In this study, the effects of stress relaxation on the thermoelectric properties (carrier concentration n, Hall mobility μH, weighted mobility μW, density-of-state mass md*, Seebeck coefficient S, and thermopower factor PF) of undoped ZnO films were rationalized in terms of native defects (VO-related defects and Zni-related donors) induced through the deposition temperature (TD) during the sputtering process. All investigated ZnO films exhibited compressive stress and tended to become less compressive with increasing TD. The stress relaxation at high TD resulted in improved film crystallization and decreased native defect concentration, thus significantly enhancing md* through the reduction of intrinsic lattice defects, while less carriers were trapped and scattered by defects. Therefore, n and μ increased simultaneously (by 28 times and one order of magnitude, respectively), markedly enhancing the PF of dopant-free ZnO films.
The impact of thixotropic behavior on microfluidic mixing in a staggered-herringbone mixer
Authors: Park Jo Eun , Kang Tae Gon , Jung Seon Yeop
Published: April 2024

This study numerically explores the influence of thixotropy on flow and mixing in a staggered-herringbone micromixer (SHM), employing a structure-kinetics model to simulate the microstructure formation and breakup in thixotropic fluids. This study represents the first of its kind to incorporate a thixotropic fluid model into microfluidic mixing in channels with patterned grooves. Specifically, we examine the effects of the destruction factor (kd) and the thixotropy number (Th) on microstructure, flow, and mixing in the SHM, covering extensive ranges (0.01≤kd≤10 and 0.01≤Th≤100). Higher values of kd and Th, particularly for kd>1 and Th>1, lead to larger spatial variations of the structure parameter (λ) and viscosity (η), with a notable decrease in λ near the groove tops, leading to the lowest viscosity in these areas. Conversely, at the groove bottoms, where shear deformation is minimal, there is less reduction in λ, leading to increased viscosity and higher flow resistance. The viscosity variations inside the grooves impede lateral flows, adversely affecting mixing in the higher kd and Th regimes. Therefore, an in-depth understanding of the complex thixotropic behaviors, as influenced by kd and Th near the grooves, is essential for achieving effective mixing in the SHM when using thixotropic fluids. Our results suggest that lowering the channel height, for a given groove depth, slightly improves the mixing of thixotropic fluids. Further enhanced mixing is achieved by combining a reduced channel height with double-sided groove patterns.
On a kneading theory for gene-splicing
Authors: Speakman Ethan , Gunaratne Gemunu H.
Published: April 2024

Two well-known facets in protein synthesis in eukaryotic cells are transcription of DNA to pre-RNA in the nucleus and the translation of messenger-RNA (mRNA) to proteins in the cytoplasm. A critical intermediate step is the removal of segments (introns) containing ∼97% of the nucleic-acid sites in pre-RNA and sequential alignment of the retained segments (exons) to form mRNA through a process referred to as splicing. Alternative forms of splicing enrich the proteome while abnormal splicing can enhance the likelihood of a cell developing cancer or other diseases. Mechanisms for splicing and origins of splicing errors are only partially deciphered. Our goal is to determine if rules on splicing can be inferred from data analytics on nucleic-acid sequences. Toward that end, we represent a nucleic-acid site as a point in a plane defined in terms of the anterior and posterior sub-sequences of the site. The “point-set” representation expands analytical approaches, including the use of statistical tools, to characterize genome sequences. It is found that point-sets for exons and introns are visually different, and that the differences can be quantified using a family of generalized moments. We design a machine-learning algorithm that can recognize individual exons or introns with 91% accuracy. Point-set distributions and generalized moments are found to differ between organisms.
Low oxidation conditions in pulsed laser deposition enhance polarization without degradation of endurance and retention in Hf0.5Zr0.5O2 films
Authors: Ali Faizan , Song Tingfeng , Fina Ignasi , Sánchez Florencio
Published: April 2024

Interplay between oxygen vacancies and the stabilization of the ferroelectric orthorhombic phase in doped HfO2, as well as the resulting impact on endurance and retention, is far from being well understood. In Hf0.5Zr0.5O2 (HZO) thin films, it is commonly found that high polarization occurs usually at the the expense of robustness upon cycling due to the polarization–endurance dilemma. It has been reported that HZO thin films grown by pulsed laser deposition under the mixed Ar and O2 atmosphere exhibit a high polarization. Here, we show that this strategy enables functional properties tuning, allowing to obtain HZO films with high polarization at low oxidation conditions without degradation of endurance and retention.
Anomalous electrohydrodynamic cross-stream particle migration
Authors: Abdorahimzadeh Seyedamirhosein , Bölükkaya Zikrullah , Vainio Seppo J. , Liimatainen Henrikki , Elbuken Caglar
Published: April 2024

Particle cross-stream migration in electrohydrodynamic microfluidic systems exhibits intriguing behaviors, which makes it interesting when viewed from a fundamental perspective and promising for nanoparticle focusing and separation applications. So far, particle behavior in such systems has been explained with the slip-induced lift force model (Saffman model), which predicts particle central or side focusing based on the direction of electric field and fluid flow. However, in our previous work, we observed particle migration patterns that did not adhere to the prediction of the Saffman model. In this work, we further studied this novel particle lateral migration behavior, which we termed the “anti-Saffman” behavior. We experimentally investigated how changing the conductivity of the suspending medium influences particle behavior and quantitatively measured the net lateral force experienced by the particles. Then, we compared this net force with the prediction of the relevant lift force models in the literature. We concluded that the anti-Saffman behavior is positively correlated with medium conductivity and shear rate (∝γ̇2). Furthermore, the comparison with the existing force models revealed that none of them can predict the experimentally observed particle lift. The net lift predicted by hydrodynamic lift models indicated that the underlying mechanism behind our experiments also potentially has a hydrodynamic origin. We believe this phenomenon offers the possibility of manipulating and separating nanoparticles suspended in standard aqueous electrolyte solutions, which makes it applicable to various biological samples.
Simulated signatures of ignition
Authors: Haines Brian M. , Meaney K. D. , Kuczek J. J. , Albright B. J. , Daughton W. S. , Hoffman N. M. , Lester R. S. , Sauppe J. P.
Published: April 2024

Ignition on the National Ignition Facility (NIF) provides a novel opportunity to evaluate past data to identify signatures of capsule failure mechanisms. We have used new simulations of high-yield implosions as well as some from past studies in order to identify unique signatures of different ignition failure mechanisms: jetting due to the presence of voids or defects, jetting due to the capsule fill tube, interfacial mixing due to instabilities or due to plasma transport, radiative cooling due to the presence of contaminant in the hot spot, long-wavelength drive asymmetry, and preheat. Many of these failure mechanisms exhibit unique trajectories that can be distinguished through variations in experimental observables such as neutron yield, down-scattered ratio (DSR), and burn width. Our simulations include capsules using both plastic and high-density carbon ablators and span all high-yield designs considered since the beginning of the National Ignition Campaign in 2011. We observe that the variability in trajectories through the space of neutron yield, DSR, and burn width varies little across capsule design yet are unique to the failure mechanism. The experimental trajectories are most consistent with simulated preheat and jetting due to voids and defects, which are the only failure mechanisms that are indistinguishable in our analysis. This suggests that improvements to capsule compression due to improved capsule quality or reduced preheat have played a primary role in enabling high yields on NIF. Furthermore, our analysis suggests that further improvements have the potential to increase yields further.
Ion cyclotron emission in Maxwellian plasmas
Authors: Kolesnichenko Ya. I. , Lutsenko V. V. , Tykhyy A. V.
Published: April 2024

Destabilization of ion cyclotron waves—waves with frequencies close to ion cyclotron harmonics—in inhomogeneous plasmas with Maxwell velocity distribution is considered. A new mechanism of destabilization of these waves is found, whereas the known interaction between cyclotron waves and drift waves is shown to be hardly able to lead to instabilities in realistic tokamak plasmas. Our finding is that the resonance wave–particle interaction in the presence of temperature gradient can change the diamagnetic drift frequency in such a way that the destabilizing influence of the diamagnetic drift exceeds Landau damping. This occurs when the energy of resonance particles is sufficiently high, which is always the case due to the infinite tail of the Maxwell distribution. Particles with higher energies provide a larger ratio of drive to damping, but the number of resonance particles and, thus, instability growth rates are exponentially small when particle energy is very high. Therefore, only moderately suprathermal particles can lead to observable instabilities. A condition for instabilities driven by these particles is obtained. Destabilization of electrostatic cyclotron waves and ordinary cyclotron waves is studied.
On beat-driven and spontaneous excitations of zonal flows by drift waves
Authors: Chen Liu , Qiu Zhiyong , Zonca Fulvio
Published: April 2024

Using the slab plasma as a paradigm model, we have derived analytically equations for the nonlinear generation of zero-frequency zonal flows by electron drift waves including, on the same footing, both the beat-driven and spontaneous excitations. It is found that the beat-driven zonal flow tends to reduce the frequency mismatch between the electron drift waves and, thereby, contributes to a significant O(1) enhancement of the modulational instability drive and lowering its threshold. Implications to tokamaks plasmas as well as drift-wave soliton formation are also discussed.
Computational hemodynamics and hemoacoustic study on carotid bifurcation: Effect of stenosis and branch angle
Authors: Morab Sumant R. , Murallidharan Janani S. , Sharma Atul
Published: April 2024

Investigation of sound-signal-based noninvasive diagnosis of arterial stenosis is an active area of research. This study focuses on computational investigation of hemodynamic and hemoacoustic parameters within the carotid bifurcation. The objective is to analyze the effect of 40 distinct geometric configurations on indicative sound signals, useful for understanding the feasibility of stethoscope-based diagnosis of stenosis. The study employs an in-house flow-solver based on the semi-implicit pressure-projection method on a curvilinear grid. Physiological condition-based pulsatile flow waveforms and three-element Windkessel model-based pressure are utilized at the inlet and outlets of the bifurcating carotid artery. The research involves assessment of parameters like wall shear stress (WSS) and integrated pressure force rate (IPFR) fast Fourier transform (FFT) spectrum. Geometric configurations are varied based on stenosis level S (0, 45%, 60%, and 70%), bifurcation angle BA (30°, 40°, 50°, and 65°), and length of stenosis L (1, 1.5, and 2). In the investigated geometries, WSS exhibits a distinct behavior, reaching a peak at stenosis and subsequently transitioning to a negative value. Furthermore, IPFR-spectrum analysis reveals distinguishable frequencies for S≥ 40%, hinting at the potential for stethoscope-based diagnosis. A novel correlation between the cutoff frequencies of IPFR FFT-spectrum and arterial geometry is established, which reflect the influence of artery geometry on sound signals. Computational fluid dynamics (CFD)-based flow-visualization approach is proposed to calculate characteristic frequencies, which are close to IPFR spectrum frequencies. Our study contributes to a framework for potential sound-based classification of plaque-induced constrictions.
Heat transport at the nanoscale and ultralow temperatures—Implications for quantum technologies
Authors: Majidi Danial , Bergfield Justin P. , Maisi Ville , Höfer Johannes , Courtois Hervé , Winkelmann Clemens B.
Published: April 2024

In this Perspective, we discuss thermal imbalance and the associated electron-mediated thermal transport in quantum electronic devices at very low temperatures. We first present the theoretical approaches describing heat transport in nanoscale conductors at low temperatures, in which quantum confinement and interactions play an important role. We then discuss the experimental techniques for generating and measuring heat currents and temperature gradients on the nanoscale. Eventually, we review the most important quantum effects on heat transport and discuss implications for quantum technologies and future directions in the field.
The retranslator as the propagandist of MOI
Authors: Afzali Katayoon
Published: April 2024

Translations are reflections of their historical, social, cultural, and political contexts. Given this, the
current study aimed to explore the ways Nicholson (1898) and Arberry (1967) dealt with translating culture-bound terms and Quranic
allusions in the translations of Rumi’s mystical poems in Divan-e-Shams-e- Tabrizi into English and then identify
the textual relationships between the two. To do so, the comparative model of research and the notion of tertium
comparationis was used. The strategies used by (re)translators for translating culture-bound terms and Quranic
allusions were first identified and categorized in a selection of twenty poems from Divan-e-Shams-e- Tabrizi. The
study’s findings showed strong filial relationships between the two versions, where both had used cultural adaptation and
explicitation of cultural-bound terms by using the addition strategy used in their endnotes. However, the dissidence lay in the
content of the endnotes, and the way discursive contexts of the (re)translators shaped their translation strategies was
discussed.
PolylexFLE
Authors: Todirascu Amalia , François Thomas , Cargill Marion
Published: April 2024

MWE knowledge is key in the process of learning a foreign language, but its teaching remains hindered by the lack
of list of expressions connected to pedagogical aims. In this paper, we present an extended version of the PolylexFLE database,
containing 4,525 French multiword expressions (MWE) of three types: idioms, collocations or fixed expressions. In order to propose
exercises following the difficulty scale of the European Framework of Reference for Languages (CEFR), we used a mixed approach
(manual and automatic) to annotate 1,186 expressions according to the CEFR levels. The paper focuses mostly on the automatic
procedure that first identifies the expressions from the PolylexFLE database (and their variants) in a corpus of pedagogical texts
(with CEFR labels) using a pattern-based system. In a second step, their distribution in this corpus is estimated and transformed
into a single CEFR level. The automatic approach proposed is finally evaluated by 52 French as foreign language learners.
The function of the pointing gesture-speech combination in children’s story retelling
Authors: Minto-García Aline , Alva Canto Elda Alicia , Arias-Trejo Natalia , Jasso Tania
Published: April 2024

The use of multimodal communication provides information about children’s language development. From early ages, combinations of gesture and speech are part of communication and meaning processes in different discursive contexts. Our aim was to identify the types of pointing gesture-speech combinations and their communicative functions in the story retelling of 30-, 36-, 42-, and 48-month-old children. We analyzed the children’s retellings (in the context of joint attention with a book) by first identifying whether the pointing gesture-speech combinations were complementary or supplementary and then coding the communicative function of the combinations as assertive, directive, or expressive. The results showed a greater proportion of complementary combinations in all age groups, and a greater frequency of the assertive function in both complementary and supplementary combinations. This study provides evidence about the role of the pointing gesture-speech combinations in Mexican children’s story retelling and how their multimodal communication develops in this narrative context.
University students’ perceptions of team teaching by native and non-native speakers in a Spanish course
Authors: Song Yerim
Published: April 2024

This study investigated the perceptions of 200 Korean students of Spanish as a foreign language regarding team teaching by a Korean Spanish teacher (KST) and a native Spanish-speaking teacher (NST) in a university Spanish course. The survey focused on the students’ views on the weight and demand of learning areas in the lectures, the teaching method and attitude of each instructor, and the advantages and disadvantages of each teacher. The questionnaire asked the students to evaluate the overall team teaching to discern their expectations of the Spanish classes. The results showed that the students had high demands for speaking in both the KST’s and NST’s classes and indicated the advantages and disadvantages of both types of teachers. A relationship was found between the language proficiency level of the students and their preference for instructors, and the use of the first language was considered positive. Overall, the team teaching was evaluated as ideal.
Assessing voice vs. writing quality
Authors: Homayounzadeh Maryam , Rahimi Mohammad
Published: April 2024

Using a mixed-methods design, the study aimed to distinguish voice features from the criteria considered in most L2 writing rating scales (e. g., topic development, organization, and quality of language use). Accordingly, a sample of 200 argumentative essays written in English was scored for voice, writing quality, and the critical features of academic writing such as text length, lexical sophistication, and grammatical complexity (see Cumming et al., 2005). Multiple regression and structural equation modeling (SEM) were conducted to verify which of and how the critical elements of academic writing interacted to determine the scores for voice and writing quality. Think-aloud protocols (TAPs) of raters scoring voice and writing quality were also compared. Voice was found an indication of genre competence, rated independently of language use and mostly based on the structure of arguments and the quality with which writers employed certain textual voice elements. In assessing writing quality, however, textual voice elements were dismissed, and the writing quality scores mainly reflected the quality of language use rather than the argument structure. The study provides implications for second language writing assessment and instruction, as well as for future research to be conducted.
Access and Equity through the Greenbelt Venture Program
Authors: Elvy Makela
Published: April 2024

This case study documents the development of the Greenbelt Venture program, a 10-week, youth leadership program providing youth from underserved neighborhoods in Staten Island, NY access to the local forest from the viewpoint of the educator. The case study discusses a unique pedagogical approach that centers equity and access to meet programmatic goals. The case study offers critical reflections on the development process and success metrics that enable the educators to overcome challenges and yield similar qualitative results as other comparable outdoor adventure programs despite the inner-city location.

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© CAB International 2024
Twistor initial data characterisation of pp-waves
Authors: Gasperín Edgar , Pais Francisco
Published: April 2024

This note gives a concise derivation of a twistor-initial-data characterisation of pp-wave spacetimes in vacuum. The construction is based on a similar calculation for the Minkowski spacetime in Bäckdahl and Kroon [2011 Class. Quantum Grav.
28 075010]. The key difference is that for the Minkowski spacetime a necessary condition is that

∇

A

A

′

κ
¯

A

′

≠
0

. In this note it is shown that if

∇

A

A

′

κ
¯

A

′

=
0

then the development is a pp-wave spacetime. Furthermore, it is shown that such condition propagates off the initial hypersurface, which, in turn, gives a twistor initial data characterisation of pp-waves.
Anisotropic compact star in linear f(Q)-action
Authors: Maurya S K , Errehymy Abdelghani , Vîlcu Gabriel-Eduard , Alrebdi Haifa I , Nisar Kottakkaran Sooppy , Abdel-Aty Abdel-Haleem
Published: April 2024

In this paper, a significant leap forward in understanding compact stellar systems and the modified f(Q) gravity theory is achieved. The pivotal discovery lies in the successful derivation of an exact solution that fulfils the static geometry and spherical symmetry criteria, permitting the study of compact stellar configurations with an anisotropic fluid. The model is rigorously tested and satisfies the vital physical conditions within the stellar fluid, guaranteeing its viability. The numerical values of constant parameters have been calculated by using the observational data of the compact star, namely, Her X-1. The equi-mass contours highlight an impressive correlation between the f(Q) gravity parameters. Boosting α while keeping β fixed and concurrently boosting R leads to a significant global boost in mass distribution. This can be ascribed to the enhanced coupling arising from a higher α, which broadens the mass distribution. In addition, the larger object size arising from the rise in R allows for more mass accommodation. Therefore, raising both R and α leads to an exaggerated mass distribution, proving the combined influence of coupling strength and object size on total mass. Altogether, this investigation advances our knowledge of compact stellar systems and supports the evolution of the modified f(Q) theory of gravity, opening the way for more breakthroughs in this field.
L2SR: learning to sample and reconstruct for accelerated MRI via reinforcement learning
Authors: Yang Pu , Dong Bin
Published: April 2024

Magnetic resonance imaging (MRI) is a widely used medical imaging technique, but its long acquisition time can be a limiting factor in clinical settings. To address this issue, researchers have been exploring ways to reduce the acquisition time while maintaining the reconstruction quality. Previous works have focused on finding either sparse samplers with a fixed reconstructor or finding reconstructors with a fixed sampler. However, these approaches do not fully utilize the potential of joint learning of samplers and reconstructors. In this paper, we propose an alternating training framework for jointly learning a good pair of samplers and reconstructors via deep reinforcement learning. In particular, we consider the process of MRI sampling as a sampling trajectory controlled by a sampler, and introduce a novel sparse-reward partially observed Markov decision process (POMDP) to formulate the MRI sampling trajectory. Compared to the dense-reward POMDP used in existing works, the proposed sparse-reward POMDP is more computationally efficient and has a provable advantage. Moreover, the proposed framework, called learning to sample and reconstruct (L2SR), overcomes the training mismatch problem that arises in previous methods that use dense-reward POMDP. By alternately updating samplers and reconstructors, L2SR learns a pair of samplers and reconstructors that achieve state-of-the-art reconstruction performances on the fastMRI dataset. Codes are available at https://github.com/yangpuPKU/L2SR-Learning-to-Sample-and-Reconstruct.
Interplay of intermolecular and intramolecular vibrations mediates ultrafast singlet fission
Authors: Cui Binjie , Jha Ajay , Duan Hong-Guang
Published: April 2024

Singlet fission (SF) is an exciton multiplication process that splits a singlet exciton in organic semiconductors into two triplet excitons and thus, can overcome the Shockley–Queisser limit to improve the solar energy conversion efficiency in photovoltaics. In this paper, we construct a unified model for the ultrafast primary step of the SF process. To achieve this, we investigate the dynamics of vibrational modes and their interactions with the relevant electronic excited states in prototypical SF materials, pentacene (exothermic SF) and tetracene (endothermic SF) single crystals. Additionally, the functional role of the charge transfer (CT) state is also examined. Using the refined parameters obtained from the reported experimental results, we deduce that the intermolecular vibrations mediate the SF in pentacene with the assistance from strong vibronic couplings to intramolecular modes, which drives the SF process to occur within 100 fs. In this timescale, the CT state has a limiting role towards the SF process in pentacene. However, the CT state plays an important role in a relatively slower SF process in tetracene. Our results disentangle the role of underlying vibrational coherences and clarify the importance of the CT state in tetracene crystal. Hence, with our unified model, we can study the coherent dynamics of the SF process, which can principally be extended to other SF materials as well.
Terahertz narrow-band filter based on 3D-printed periodic waveguides
Authors: Wang Xiang-Yu , Liu Huan , Ma Jing , Li Jie , Chen Wen , Zhang Ya-Yun , Fan Ya-Xian , Tao Zhi-Yong
Published: April 2024

Terahertz (THz) devices, especially waveguide-type functional devices related to transmission and control, are severely scarce due to the lack of effective design and fabrication methods. Here, we experimentally demonstrate a waveguide type of THz narrow-band filter based on 3D-printed technology, which is realized by a cylindrical hollow metal structure with corrugated tube walls. The semi-cylindrical periodic corrugations are 3D printed on a photosensitive resin substrate material, followed by sputtering a layer of gold film on its surface to endow the structure with THz filtering functions. A hollow cylindrical corrugated waveguide is obtained by assembling two identical semi-circular corrugations together. The periodic structure with Bragg resonances can produce a frequency stop band, in which the propagation of THz waves is significantly suppressed. We print a wider section of corrugations in the middle of the waveguide, which destroys the perfect periodicity of the structure and forms a defect. Due to the local resonance caused by the defect, we observe an additional narrow-band transmission peak within the former stop band, which is a good candidate for THz filtering. The filtering bandwidth and extinction ratio are 1.8 GHz and 28 dB, respectively, and the Q-factor reaches 234. The proposed 3D-printed THz filter has the advantages of the simple structure, excellent performance, and easy integration, which can improve the existing THz systems in various applications.