bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing time-resolved plasma-driven solution electrochemistry in a falling liquid film plasma reactor: Identification of HO2− as a plasma-derived reducing agent
Authors: Srivastava Tanubhav , Chaudhuri Subhajyoti , Rich Christopher C. , Schatz George C. , Frontiera Renee R. , Bruggeman Peter
Published: March 2024

Many applications involving plasma–liquid interactions depend on the reactive processes occurring at the plasma–liquid interface. We report on a falling liquid film plasma reactor allowing for in situ optical absorption measurements of the time-dependence of the ferricyanide/ferrocyanide redox reactivity, complemented with ex situ measurement of the decomposition of formate. We found excellent agreement between the measured decomposition percentages and the diffusion-limited decomposition of formate by interfacial plasma-enabled reactions, except at high pH in thin liquid films, indicating the involvement of previously unexplored plasma-induced liquid phase chemistry enabled by long-lived reactive species. We also determined that high pH facilitates a reduction-favoring environment in ferricyanide/ferrocyanide redox solutions. In situ conversion measurements of a 1:1 ferricyanide/ferrocyanide redox mixture exceed the measured ex situ conversion and show that conversion of a 1:1 ferricyanide/ferrocyanide mixture is strongly dependent on film thickness. We identified three dominant processes: reduction faster than ms time scales for film thicknesses >100 µm, •OH-driven oxidation on time scales of <10 ms, and reduction on 15 ms time scales for film thickness <100 µm. We attribute the slow reduction and larger formate decomposition at high pH to HO2− formed from plasma-produced H2O2 enabled by the high pH at the plasma–liquid interface as confirmed experimentally and by computed reaction rates of HO2− with ferricyanide. Overall, this work demonstrates the utility of liquid film reactors in enabling the discovery of new plasma-interfacial chemistry and the utility of atmospheric plasmas for electrodeless electrochemistry.
Transport cross sections and collision integrals for N(4S)–O(3P) and N(4S)–O(1D) interactions in high-temperature air plasmas
Authors: Ding Zi , Qin Zhi , Liu Linhua
Published: March 2024

Collisions between nitrogen (N) and oxygen (O) play a crucial role in determining transport coefficients in high-temperature atmospheres of Earth and planetary. In this study, the momentum transfer, viscosity, third-moment, and fourth-moment transport cross sections for the N(4S)–O(3P) and N(4S)–O(1D) interactions are reported in the collision energy range of 10−6–10 Hartree based on the classical and semiclassical methods. The new and accurate potential energy curves for N–O interactions, which are used to provide the input for calculations of the cross sections, are calculated based on the state-of-the-art ab initio method. The classical and semiclassical collision integrals are provided at 300–50 000 K, and the results support the calculation of transport coefficients in a third-order approximation. In particular, the collision data for the N(4S)–O(1D) interaction based on ab initio points are reported for the first time. The calculated transport cross sections and collision integrals are helpful for studies of modeling the high-temperature air plasmas.
Transfer of III-nitride epitaxial layers onto pre-patterned silicon substrates for the simple fabrication of free-standing MEMS
Authors: Gujrati Rajat , Kassem Ali , Ayela Cédric , Mathieu Fabrice , Nicu Liviu , Sundaram Suresh , Dufour Isabelle , Hunt William , Ougazzaden Abdallah , Salvestrini Jean-Paul , Leichlé Thierry
Published: March 2024

In recent years, the remarkable properties and potential applications of III-nitride (III-N) semiconductors have sparked a significant interest in the field of microelectromechanical systems (MEMS). Traditionally, III-N MEMS are fabricated through a process involving the epitaxial growth of III-N epilayers on a silicon substrate followed by etching the handle wafer to generate free-standing structures. In this study, we explore the potential of a relatively simple approach based on the two-dimensional (2D) material-based liftoff and transfer to fabricate III-N mechanical resonators. The methodology involves van der Waals epitaxy of III-N layers on 2D hexagonal-boron nitride (h-BN), which leverages the weak van der Waals adhesion between h-BN layers to lift off and transfer these layers from their original growth substrate to an alternative host substrate. The employed method is demonstrated by fabricating 600 nm thick GaN/AlGaN and 2.5 μm thick h-BN micro-resonators onto pre-patterned cavities etched in silicon substrates. These devices are characterized using laser Doppler vibrometry, enabling the observation of well-defined modes of vibration and resonant frequencies. Furthermore, finite element method simulations are performed to gain insights into the experimental observations and the mechanical properties of the transferred layers. This approach could be extended to transfer high-quality III-N MEMS devices onto various host substrates, including flexible substrates, and could be used to assess the mechanical properties of emerging III-N semiconductor materials.
Hyperfine and Zeeman interactions in ultracold collisions of molecular hydrogen with atomic lithium
Authors: Jóźwiak Hubert , Tscherbul Timur V. , Wcisło Piotr
Published: March 2024

We present a rigorous quantum scattering study of the effects of hyperfine and Zeeman interactions on cold Li–H2 collisions in the presence of an external magnetic field using a recent ab initio potential energy surface. We find that the low-field-seeking states of H2 predominantly undergo elastic collisions: the ratio of elastic-to-inelastic cross sections exceeds 100 for collision energies below 100 mK. Furthermore, we demonstrate that most inelastic collisions conserve the space-fixed projection of the nuclear spin. We show that the anisotropic hyperfine interaction between the nuclear spin of H2 and the electron spin of Li can have a significant effect on inelastic scattering in the ultracold regime, as it mediates two processes: the electron spin relaxation in lithium and the nuclear spin–electron spin exchange. Given the predominance of elastic collisions and the propensity of inelastic collisions to retain H2 in its low-field-seeking states, our results open up the possibility of sympathetic cooling of molecular hydrogen by atomic lithium, paving the way for future exploration of ultracold collisions and high-precision spectroscopy of H2 molecules.
Multiscale analysis of turbulence in horizontal pipes: Liquid and particle-liquid flow investigation
Authors: Savari Chiya , Barigou Mostafa
Published: March 2024

An experimental–theoretical methodology is developed to investigate the characteristics of turbulence in horizontal particle-liquid pipe flows. Using a discrete wavelet transform, the three-dimensional Lagrangian trajectories of the liquid phase experimentally determined by positron emission particle tracking are decomposed into their deterministic and stochastic sub-trajectories, which are then utilized to construct profiles of local fluctuating velocity components and turbulent kinetic energy. The results for a single-phase flow are independently validated using computational fluid dynamic simulation and the analysis parameters are fine-tuned using direct numerical simulation data from the literature. In a particle-liquid flow, the investigation explores the influence of various factors including particle size, density, and concentration on turbulence intensity. Remarkably, the results demonstrate significant effects of the particle size and density on liquid turbulence. The enhanced understanding gained regarding turbulence intensity helps to advance our fundamental interpretation of the dynamics of particle-liquid flows, thus potentially aiding the rational design of such complex flows and associated equipment.
Tuning the out-of-plane magnetic textures of electrodeposited Ni90Fe10 thin films
Authors: Cotón N. , Andrés J. P. , Jaafar M. , Begué A. , Ranchal R.
Published: March 2024

This study investigates the out-of-plane magnetization component of electrodeposited Ni90Fe10 thin films grown under different applied magnetic field conditions. The formation of stripe domains is gradual, as there is a thickness range in which the transcritical shape appears in the hysteresis loops, while only magnetic ripples are measured in the magnetic force microscopy images. For instance, samples deposited under the residual magnetic field generated by the switched-off magnetic stirrer exhibit the transcritical shape in the in-plane hysteresis loops at a thickness of 400 nm, even though corresponding magnetic force microscopy images do not reveal the presence of stripe domains. When a perpendicular magnetic field of 100 Oe is applied during growth, stripe domains become visible in microscopy images, along with the transcritical shape in the hysteresis loop at 400 nm. This implies that the critical thickness for stripe formation can be reduced by applying a perpendicular magnetic field during electrodeposition. We have experimentally confirmed that the larger the magnetic field applied in the out-of-plane direction during growth, the smaller the critical thickness. These results underscore the importance of controlling the external magnetic field during electrodeposition for more effective tuning of the magnetic textures in electrodeposited Ni90Fe10 films.
Assessing the thermal conductivity of amorphous SiN by approach-to-equilibrium molecular dynamics
Authors: Lambrecht Achille , Ori Guido , Massobrio Carlo , Boero Mauro , Martin Evelyne ,   ADynMat consortium
Published: March 2024

First-principles molecular dynamics combined with the approach-to-equilibrium molecular dynamics methodology is employed to calculate the thermal conductivity of non-stoichiometric amorphous SiN. This is achieved by implementing thermal transients in five distinct models of different sizes along the direction of the heat transport. Such models have identical structural features and are representative of the same material, thereby allowing for a reliable analysis of thermal conductivity trends as a function of the relevant cell dimension. In line with the known physical law of heat propagation at short scale, the thermal conductivity increases in size with the direction of heat transport. The observed behavior is rationalized accounting for previous results on crystalline and amorphous materials, thus providing a unified description holding for a large class of materials and spanning a wide range of heat propagation lengths.
Helicity-dependent photocurrent of topological surface states in the intrinsic magnetic topological insulator MnBi2Te4
Authors: Fu Houfa , Yu Jinling , Bai Yunhe , Cheng Shuying , Lai Yunfeng , Chen Yonghai , He Ke , Xue Qikun
Published: March 2024

Helicity-dependent photocurrent (HDPC) of the topological surface states (TSSs) in the intrinsic magnetic topological insulator MnBi2Te4 is investigated. It is revealed that the HDPC is mainly contributed by the circular photogalvanic effect (CPGE) current when the incident plane is perpendicular to the connection of the two electrodes, while the circular photon drag effect plays the dominant role when the incident plane is parallel to the connection of the two electrodes. The CPGE current shows an odd function dependence on incident angles, which is consistent with the C3v symmetry group of the TSSs in MnBi2Te4. The amplitude of the CPGE current increases with the decrease in temperature, which can be attributed to the increase in mobility at low temperatures, confirmed by the transport measurements. Furthermore, we modulate the CPGE of MnBi2Te4 by applying top gate and source–drain voltages. Compared to Bi2Te3 of the same thickness, the CPGE current of MnBi2Te4 can be more effectively tuned by the top gate because the Fermi level of MnBi2Te4 can be effectively regulated by the top gate, and it is tuned across the Dirac point. This work suggests that the intrinsic magnetic topological insulator MnBi2Te4 is a good candidate for designing opto-spintronics devices.
Numerical analysis of flow past over a triangular rod through passive control method
Authors: Manzoor Raheela , Habib Rida , Nadeem Noreen , Kalsoom Shazia
Published: March 2024

A two-dimensional numerical study is conducted to investigate the effect of a control plate length on flow past over a triangular rod through a lattice Boltzmann method. The Reynolds number (Vmax d/ν) is taken within the range from Re = 50–200, and the length (L) of the control plate is varied from L = 1–5. First, we checked the adequacy of a grid point by selecting different values of grids and studied the effect of a computational domain at different values of upstream (Lu), downstream (Ld) distances and changing the height (H) of the channel. After that, we studied the effect of fluid forces on flow past a single triangular rod and then by attaching the control plate by varying its length. The results are obtained in terms of vorticity contour, drag (CD) and lift (CL) coefficients, and calculation of physical parameters (CDmean, CDrms, CLrms, and St). In terms of vorticity contour, we examined four various types of flow regimes. These are (i) steady flow regime (SFR), (ii) quasi-steady flow regime (QSFR), (iii) shear layer reattachment flow regime, and (iv) single bluff body flow regime based on the flow structure mechanism. In calculation of physical parameters, we observed that the mean drag coefficient contains a maximum value for the case of the single triangular rod as compared to presence of the attached control plate. Second, it is noticed that, as the Reynolds number increases, the values of CDmean gradually decreases, but at the highest range of Reynolds number and largest length of the control plate, the value of the mean drag coefficient increases and produces more fluid forces. CDrms also shows similar behavior like CDmean. The root mean square values of lift coefficients become zero at (L, Re) = (1, 50), (2, 50), (2, 80), (3, 50), (3, 80), (3, 100), (4, 50), (4, 80), (4, 100), (4, 120), (5, 50), (5, 80), (5, 100), (5, 120), and (5, 150), respectively. The St containing maximum value at (L, Re) = (2, 200) and minimum value at (L, Re) = (5, 200). Furthermore, at lengths L = 1–5, the value of St = 0 due to no lift forces at (L, Re) = (1, 50), (2, 50), (3, 50), and (4, 50) and (2, 80), (3, 80), (3, 100), (4, 120), and (5, 150), respectively. The maximum reduction in CDmean is found to be about 16.89%. Overall, the findings suggest complex interactions between Reynolds number, control plate length, and various coefficients, impacting the flow structure and shedding characteristics.
Design and analysis of an ideal scramjet flowpath
Authors: Lee Gyu Sub , Lee Tonghun
Published: March 2024

The current work presents a novel conceptual framework for the fluid and gasdynamics that govern the design and performance of an ideal scramjet flowpath. These include a theoretical comparison between ram and scram modes, the physics of thrust loss during inlet unstart, and the design of an optimal scramjet flowpath. We present a unique explicit, closed-form relation for the wall divergence of an ideal scramjet combustor. The accompanying derivations and discussions, which leverage this formulation, seek to address uncertainties and misconceptions regarding the dominant fluid processes present in these engines. It is shown that scram and ram modes exhibit theoretical similitude for maximum thrust potential at conditions beyond the one-dimensional Rayleigh choking limit but can diverge below the global choking threshold. Additionally, it is shown that even for an ideal scramjet heat engine cycle, thermodynamic efficiencies at various flight conditions deviate from those of the classical Brayton cycle. These insights and accompanying theoretical analyses are meant to establish a foundation for the thermodynamics and gasdynamics relevant to the performance of dual-mode scramjet engines. The resulting work offers an intuitive technical perspective on supersonic combustion and the fundamentals of dual-mode scramjet operation that can be applied across a wide range of scramjet-related experimental and computational studies and design efforts in the future.
Room temperature electrical characteristics of gold-hyperdoped silicon
Authors: Lim Shao Qi , Warrender Jeffrey M. , Notthoff Christian , Ratcliff Thomas , Williams Jim S. , Johnson Brett C.
Published: March 2024

Hyperdoped silicon is a promising material for near-infrared light detection, but to date, the device efficiency has been limited. To optimize photodetectors based on this material that operate at room temperature, we present a detailed study on the electrical nature of gold-hyperdoped silicon formed via ion implantation and pulsed-laser melting (PLM). After PLM processing, oxygen-rich and gold-rich surface layers were identified and a wet etch process was developed to remove them. Resistivity and Hall effect measurements were performed at various stages of device processing. The underlying gold-hyperdoped silicon was found to be semi-insulating, regardless of whether the surface gold was removed by etching or not. We propose a Fermi level pinning model to describe the band bending of the transformed surface layer and propose a promising device architecture for efficient Au-hyperdoped Si photodetectors.
Hopping nature of the Hall effect in a samarium nickelate film
Authors: Stupakov Alexandr , Kocourek Tomáš , Pacherová Oliva , Suchaneck Gunnar , Dejneka Alexandr , Tyunina Marina
Published: March 2024

We analyzed the temperature dependencies of the DC resistivity and Hall coefficient in thin films of samarium nickelate SmNiO3. A dominating hopping conductivity was revealed in the insulating phase below 400 K, which defines an exponential drop in the Hall coefficient with temperature. The estimated dependencies of the hopping activation energy, Hall mobility, and charge carrier density suggest that small polarons are responsible for hopping. The hopping transport explains the observed sign anomaly of the Hall coefficient in rare-earth nickelates.
A community of practice intervention to increase education-focused mental health promotion actions among interdisciplinary professionals: a qualitative study
Authors: Tokolahi Ema , Richardson Deirdre , Bazyk Susan
Published: March 2024

Introduction Through a unique, inter-sectoral and interprofessional initiative, practitioners from education, health and social service sectors were invited to participate in communities of practice, facilitated online. The focus was on building workforce capacity to address the mental health needs of children and youth. Aim This paper explores interprofessional workforce development by translating knowledge from a mental health promotion initiative developed overseas into the Aotearoa New Zealand context. Methods Over a 6-month period, practitioners engaged in an iterative, capacity-building process, where they had access to the initiative materials and resources, shared practice stories, networked, and discussed barriers and facilitators for implementation. Qualitative thematic analysis was used to interpret data. Results Members of the communities of practice engaged in storytelling and made sense of the initiative in relation to their previous knowledge and experiences: practice and thinking were validated. Mental health promotion was positioned as the responsibility of all sectors and the need for effective interprofessional collaboration was deemed essential. Furthermore, translation of the initiative into the bicultural context of Aotearoa New Zealand demanded and deserved sustained attention. Discussion This study contributes interprofessional and inter-sectoral evidence for building workforce capacity to address the mental health needs of children and youth. Further research is warranted to investigate the outcomes for the children and youth served. Interprofessional communities of practice were shown to provide a sustainable mechanism by which knowledge can be received, transformed and translated into practice.
An escape route planning model based on wildfire prediction information and travel rate of firefighters
Authors: Sheng Junhao , Li Xingdong , Wang Xinyu , Wang Yangwei , Li Sanping , Li Dandan , Sun Shufa , Zhao Lijun
Published: March 2024

Background When firefighters evacuate from wildfires, escape routes are crucial safety measures, providing pre-defined pathways to a safety zone. Their key evaluation criterion is the time it takes for firefighters to travel along the planned escape routes. Aims While shorter travel times can help firefighters reach safety zones faster, this may expose them to the threat of wildfires. Therefore, the safety of the routes must be considered. Methods We introduced a new evaluation indicator called the safety index by predicting the growth trend of wildfires. We then proposed a comprehensive evaluation cost function as an escape route planning model, which includes two factors: (1) travel time; and (2) safety of the escape route. The relationship between the two factors is dynamically adjusted through real time factor. The safety window within real time factor provides ideal safety margins between firefighters and wildfires, ensuring the overall safety of escape routes. Key results Compared with other models, the escape routes planned by the final improved model not only effectively avoid wildfires, but also provide relatively short travel time and reliable safety. Conclusions This study ensures sufficient safety margins for firefighters escaping in wildfire environments. Implications The escape route model described in this study offers a broader perspective on the study of escape route planning.
Learning shapes the development of migratory behavior
Authors: Aikens Ellen O. , Nourani Elham , Fiedler Wolfgang , Wikelski Martin , Flack Andrea
Published: March 2024

How animals refine migratory behavior over their lifetime (i.e., the ontogeny of migration) is an enduring question with important implications for predicting the adaptive capacity of migrants in a changing world. Yet, our inability to monitor the movements of individuals from early life onward has limited our understanding of the ontogeny of migration. The exploration–refinement hypothesis posits that learning shapes the ontogeny of migration in long-lived species, resulting in greater exploratory behavior early in life followed by more rapid and direct movement during later life. We test the exploration–refinement hypothesis by examining how white storks (
Ciconia ciconia
) balance energy, time, and information as they develop and refine migratory behavior during the first years of life. Here, we show that young birds reduce energy expenditure during flight while also increasing information gain by exploring new places during migration. As the birds age and gain more experience, older individuals stop exploring new places and instead move more quickly and directly, resulting in greater energy expenditure during migratory flight. During spring migration, individuals innovated novel shortcuts during the transition from early life into adulthood, suggesting a reliance on spatial memory acquired through learning. These incremental refinements in migratory behavior provide support for the importance of individual learning within a lifetime in the ontogeny of long-distance migration.
The herpesvirus UL49.5 protein hijacks a cellular C-degron pathway to drive TAP transporter degradation
Authors: Wąchalska Magda , Riepe Celeste , Ślusarz Magdalena J. , Graul Małgorzata , Borowski Lukasz S. , Qiao Wenjie , Foltyńska Michalina , Carette Jan E. , Bieńkowska-Szewczyk Krystyna , Szczesny Roman J. , Kopito Ron R. , Lipińska Andrea D.
Published: March 2024

The transporter associated with antigen processing (TAP) is a key player in the major histocompatibility class I-restricted antigen presentation and an attractive target for immune evasion by viruses. Bovine herpesvirus 1 impairs TAP-dependent antigenic peptide transport through a two-pronged mechanism in which binding of the UL49.5 gene product to TAP both inhibits peptide transport and triggers its proteasomal degradation. How UL49.5 promotes TAP degradation has, so far, remained unknown. Here, we use high-content siRNA and genome-wide CRISPR-Cas9 screening to identify CLR2
KLHDC3
as the E3 ligase responsible for UL49.5-triggered TAP disposal. We propose that the C terminus of UL49.5 mimics a C-end rule degron that recruits the E3 to TAP and engages the cullin-RING E3 ligase in endoplasmic reticulum-associated degradation.
Taking a color photo: A homozygous 25-bp deletion in
Bace2
may cause brown-and-white coat color in giant pandas
Authors: Guan Dengfeng , Sun Shuyan , Song Lingyun , Zhao Pengpeng , Nie Yonggang , Huang Xin , Zhou Wenliang , Yan Li , Lei Yinghu , Hu Yibo , Wei Fuwen
Published: March 2024

Brown-and-white giant pandas (hereafter brown pandas) are distinct coat color mutants found exclusively in the Qinling Mountains, Shaanxi, China. However, its genetic mechanism has remained unclear since their discovery in 1985. Here, we identified the genetic basis for this coat color variation using a combination of field ecological data, population genomic data, and a CRISPR–Cas9 knockout mouse model. We de novo assembled a long-read-based giant panda genome and resequenced the genomes of 35 giant pandas, including two brown pandas and two family trios associated with a brown panda. We identified a homozygous 25-bp deletion in the first exon of
Bace2
, a gene encoding amyloid precursor protein cleaving enzyme, as the most likely genetic basis for brown-and-white coat color. This deletion was further validated using PCR and Sanger sequencing of another 192 black giant pandas and CRISPR-Cas9 edited knockout mice. Our investigation revealed that this mutation reduced the number and size of melanosomes of the hairs in knockout mice and possibly in the brown panda, further leading to the hypopigmentation. These findings provide unique insights into the genetic basis of coat color variation in wild animals.
Cellular and molecular organization of the
Drosophila
foregut
Authors: Zhu Haolong , Ludington William B. , Spradling Allan C.
Published: March 2024

The animal foregut is the first tissue to encounter ingested food, bacteria, and viruses. We characterized the adult Drosophila foregut using transcriptomics to better understand how it triages consumed items for digestion or immune response and manages resources. Cell types were assigned and validated using GFP-tagged and Gal4 reporter lines. Foregut-associated neuroendocrine cells play a major integrative role by coordinating gut activity with nutrition, the microbiome, and circadian cycles; some express clock genes. Multiple epithelial cell types comprise the proventriculus, the central foregut organ that secretes the peritrophic matrix (PM) lining the gut. Analyzing cell types synthesizing individual PM layers revealed abundant mucin production close to enterocytes, similar to the mammalian intestinal mucosa. The esophagus and salivary gland express secreted proteins likely to line the esophageal surface, some of which may generate a foregut commensal niche housing specific gut microbiome species. Overall, our results imply that the foregut coordinates dietary sensing, hormonal regulation, and immunity in a manner that has been conserved during animal evolution.
Assignment of the slowly exchanging substrate water of nature’s water-splitting cofactor
Authors: de Lichtenberg Casper , Rapatskiy Leonid , Reus Michael , Heyno Eiri , Schnegg Alexander , Nowaczyk Marc M. , Lubitz Wolfgang , Messinger Johannes , Cox Nicholas
Published: March 2024

Identifying the two substrate water sites of nature’s water-splitting cofactor (Mn
4
CaO
5
cluster) provides important information toward resolving the mechanism of O-O bond formation in Photosystem II (PSII). To this end, we have performed parallel substrate water exchange experiments in the S
1
state of native Ca-PSII and biosynthetically substituted Sr-PSII employing Time-Resolved Membrane Inlet Mass Spectrometry (TR-MIMS) and a Time-Resolved
17
O-Electron-electron Double resonance detected NMR (TR-
17
O-EDNMR) approach. TR-MIMS resolves the kinetics for incorporation of the oxygen-isotope label into the substrate sites after addition of H
2
18
O to the medium, while the magnetic resonance technique allows, in principle, the characterization of all exchangeable oxygen ligands of the Mn
4
CaO
5
cofactor after mixing with H
2
17
O. This unique combination shows i) that the central oxygen bridge (O5) of Ca-PSII core complexes isolated from
Thermosynechococcus vestitus
has, within experimental conditions, the same rate of exchange as the slowly exchanging substrate water (W
S
) in the TR-MIMS experiments and ii) that the exchange rates of O5 and W
S
are both enhanced by Ca
2+
→Sr
2+
substitution in a similar manner. In the context of previous TR-MIMS results, this shows that only O5 fulfills all criteria for being W
S
. This strongly restricts options for the mechanism of water oxidation.
“I’m only half Korean but I can relate to a lot of what you said”
Authors: Choe Hanwool , Gordon Cynthia
Published: March 2024

Analyzing 20 comments posted in response to YouTube videos wherein two Asian American young women share their
“lunchbox moment” stories, or first-person past-oriented accounts of how their (white) classmates at school reacted negatively to
food that they brought from home for lunch, we demonstrate how posters collaboratively transform individual offline experiences of
marginalization and difference into online moments of inclusion, solidarity, and shared identity. Integrating research on “second
stories” (Sacks 1992), “story rounds” (Tannen
2005), online storytelling (Page 2011, 2018), and online-offline interconnections (e.g., Bolander and Locher
2020), we show how commenters of diverse backgrounds accomplish “adequation” (Bucholtz
and Hall 2005) between their different minority identities in how they convey their own lunchbox moment stories. By
using metadiscursive terms (e.g., “story”), “constructed dialogue” (Tannen 2007),
ethnic category mentions, heritage languages, familiar address terms (e.g., first name), and emojis, YouTube posters create
inclusion online and across cultural, ethnic, and spaciotemporal lines.
Multi-band tunable electromagnetically induced transparencies based on active metasurface with polarization-independent property
Authors: Ren Kun , Wang Shuo , Ren Xiaobin , Peng Weilong , Zhang Hongxia , Jia Dagong
Published: March 2024

The analogue of an electromagnetically induced transparency (EIT) spectrum is achieved using a metasurface that consists of an array of cross and L-shaped resonators. The mechanism of the EIT-like phenomenon are analyzed, and the influence of geometrical parameters on the effect is discussed. We achieve a multi-band EIT-like through structure configuration. In particular, polarization-independent EIT is realized. A potential application in sensing is suggested and the sensitivity of 65 GHz RIU−1 is obtained. We also investigate the impact of analyte and substrate on the transmission spectrum. We find that when the analyte thickness is higher than 40 μm, the EIT spectral shift is less affected by the analyte thickness. The thickness insensitive characteristics are beneficial for reducing errors caused by analyte dose, thereby improving the accuracy of sensing. By introducing a phase change material, vanadium dioxide, we obtain active control of the EIT effect. Our results provide valuable insights into the development of multi-band tunable compact devices based on metasurfaces.
Comment on ‘Pseudo hard-sphere viscosities from equilibrium molecular dynamics’
Authors: Smallenburg Frank
Published: March 2024

In a recent article, Nicasio-Collazo et al (2023 J. Phys.: Condens. Matter
35 425401) explore the viscosity of the pseudo-hard-sphere (PHS) model. In this comment, we highlight some discrepancies with expected behavior, and compare their results to new simulations of the same model as well as to true hard spheres. In contrast to the results of Nicasio-Collazo et al, our results follow the relation between shear, bulk, and longitudinal viscosity expected for isotropic fluids. Moreover, we observe clear differences in behavior between PHS and true hard sphere, and encourage future hard-sphere studies to focus on the true hard sphere model whenever possible.
Symmetric circulant matrix decomposition-based multivariable group sparse coding for rolling bearing fault diagnosis
Authors: Yuan Xing , Liu Hui , Yang Fu , Zhang Huijie
Published: March 2024

Singular value decomposition technique proves its effectiveness in mechanical signal analysis by decomposing the test signal into a series of singular spectral components of different frequency bands. Nevertheless, how to adapt this technology to the needs of cyclo-nonstationary signal and how to set the decomposition number while maintaining detailed features to obtain the optimal component containing the most fault information, remains an important issue that needs to be addressed in the field of mechanical fault diagnosis. To overcome these disadvantages, the symmetric circulant matrix decomposition (SCMD) is presented. Two main ideas structure the present technique. Firstly, symmetric circulant matrix is used to generate eigenvectors, which will better adapt to the cyclo-nonstationary signal associated with the structural symmetry of rotating machinery. Then, an impulse fluctuation measure is established to adaptively search for the decomposition number and extract the optimal component. Moreover, to better improve the impulse extraction effect of SCMD, the multivariate group sparse coding based on the multivariate correlation characteristics and intra group sparsity characteristics of impulse signals is proposed, which can enhance impulse features while preserving fault details as much as possible. The reliability and feasibility of the proposed method are verified by the experimental signals. The comparison with several classic methods shows that this method is more effectiveness in weak feature extraction.
Transfer Learning for Bearing Fault Diagnosis based on Graph Neural Network with Dilated KNN and Adversarial Discriminative Domain Adaptation
Authors: Tang Tang , Liu Zeyuan , Qiu Chuanhang , Chen Ming , Yu Ying
Published: March 2024

Graph neural networks (GNNs) have emerged as a forefront in deep learning, notably influencing research in mechanical fault diagnosis. Transfer learning, particularly through domain adaptation (DA) techniques, has found application in machinery fault diagnosis by training models under one working condition and deploying them under another. While efforts have been made to integrate GNNs with DA techniques to alleviate data distribution discrepancies by investigating the inter-sample relationships, challenges persist: reliance on K-nearest neighbor (KNN) for graph generation emphasizes close relationships, neglecting distant ones; batch processing limits real-time fault diagnosis; and transfer between different-sized bearings is nearly unexplored. To address these limitations, a novel framework for GNN-based domain adaptation in machinery fault diagnosis is proposed. Initially, a convolutional neural network extracts node embeddings from the continuous wavelet transform graph of raw vibration signals. Subsequently, a graph generation layer based on dilated KNN captures both close and distant sample relationships, addressing the long-range dependency issue. Two GNN blocks are then applied for inter-sample relationships investigation and further feature extraction with the outputs directed to a linear classifier during source domain pretraining. Following pretraining, adversarial discriminative domain adaptation is leveraged to mitigate domain distribution discrepancies. Additionally, a novel graph construction method that combines existing training samples with a new single sample is proposed, enabling fault prediction with single instances for real-time online fault diagnosis. Evaluation on datasets with varying working conditions and bearings of different sizes demonstrates the superior performance of our method to other comparison methods.
The second iterate of the Muskat equation in supercritical spaces
Authors: Paduro Esteban
Published: March 2024

The ill-posedness of the Muskat problem in spaces that are supercritical with respect to scaling is studied. The paper’s main result establishes that for a sequence of approximations of the Muskat equation obtained via Taylor expansion, their corresponding second Picard’s iterate is discontinuous around the origin in a certain family of supercritical spaces approaching a critical space.
Linear response for intermittent maps with critical point
Authors: Leppänen Juho
Published: March 2024

We consider a two-parameter family of maps

T

α
,
β

:
[
0
,
1
]
→
[
0
,
1
]

with a neutral fixed point and a non-flat critical point. Building on a cone technique due to Baladi and Todd, we show that for a class of Lq
observables

ϕ
:
[
0
,
1
]
→

R

the bivariate map

(
α
,
β
)
↦

∫
0
1

ϕ

d

μ

α
,
β

, where

μ

α
,
β

denotes the invariant SRB measure, is differentiable in a certain parameter region, and establish a formula for its directional derivative.
Regularity estimates for fully nonlinear integro-differential equations with nonhomogeneous degeneracy
Authors: Andrade Pêdra D S , dos Prazeres Disson S , Santos Makson S
Published: March 2024

We investigate the regularity of the solutions for a class of degenerate/singular fully nonlinear nonlocal equations. In the degenerate scenario, we establish that there exists at least one viscosity solution of class

C

l
o
c

1
,
α

, for some constant

α
∈
(
0
,
1
)

. In addition, under suitable conditions on degree of the operator σ, we prove regularity estimates in Hölder spaces for any viscosity solution. We also examine the singular setting and prove Hölder regularity estimates for the gradient of the solutions.
Comparative analysis on the validity of golden ratio, tri-bimaximal, hexagonal and bimaximal neutrino mixing patterns under the radiative corrections
Authors: Singh Y Monitar , Shubhakanta Singh M , Nimai Singh N
Published: March 2024

We study the comparative analysis on the validity of four popular leptonic mixing patterns viz, golden ratio (GR), tri-bimaximal (TBM), hexagonal mixing (HM) and bimaximal (BM), which are assumed to be defined at high energy scale, M

R
= 1016 GeV. We perform numerical analysis of low energy neutrino oscillation parameters through the renormalisation group equations (RGEs) in both standard model (SM) and minimal supersymmetric standard model (MSSM) with the inclusion of scale dependent vacuum expectation value (VEV). The sum of three absolute neutrino mass eigenvalues obtained from the latest Planck cosmological data, ∑∣m

i
∣ < 0.12 eV, is used as a constraint in the analysis of these four leptonic mixing patterns. We consider both normal hierarchical (NH) model and inverted hierarchical (IH) model in the analysis of these four leptonic mixing patterns, with SUSY breaking scale at m

s
= 1 TeV and

tan
β
=
67

. Among the four mixing patterns, GR is found to satisfy the latest Planck cosmological data, ∑∣m

i
∣ < 0.12 eV. Further analysis on the effect of the variation of SUSY breaking scale 1 TeV ≤ m

s
≤ 14 TeV is also studied for GR neutrino mixing pattern in NH.
Bäcklund transformation with two pseudo-potentials for a coupled KdV system
Authors: Cao Xifang
Published: March 2024

We give a Bäcklund transformation with two pseudo-potentials for a coupled KdV system, which can be derived from a single complex KdV equation. By applying the Bäcklund transformation to a trivial seed solution, we construct soliton and periodic solutions. We show that each soliton solution is invariant on a circle and each periodic solution is invariant on a closed curve, which approaches a cardioid or a circle, depending on how to choose the parameters. We also prove that the Bäcklund transformation admits a nonlinear superposition principle, which allows us to discuss nonlinear interactions of these solutions.
Novel quantum solutions to privacy-preserving point-line relation determination
Authors: Peng Zhen-Wan , Shi Run-Hua , Ding Ran , Zhang Fei-Fan
Published: March 2024

Secure multiparty computational geometry is an essential field of secure multiparty computation. It involves solving geometric problems without disclosing any private geometric information from each participating party. Privacy-preserving point-line relation determination, a pivotal branch of secure multiparty computational geometry, holds significant potential for applications in various domains, including business, engineering, and military. In this paper, leveraging the assistance of a third party, we introduce a quantum solution to privacy-preserving point-line relation determination. This approach incorporates quantum key distribution and one-time pad encryption. Under the condition that the third party does not conspire with any participant, our protocol ensures heightened security and enhanced privacy protection compared to classical methods. This superiority is attributed to the underlying principles of quantum mechanics and the utilization of one-time pad encryption. Furthermore, we extend our protocol to involve multiple third parties, employing the technology of quantum secret sharing. In scenarios where these third parties refrain from colluding with any single participant, no information is divulged to the other participant. Consequently, the protocol becomes more rational and secure when multiple third parties are involved.
Research on the results of secondary school physics education of Generation Z in the Czech Republic
Authors: Mandíková Dana , Pschotnerová Petra
Published: March 2024

There are no uniform exit tests in physics at the end of secondary school studies in the Czech Republic to give a picture of what students take away from their physics studies. Therefore, we decided to take advantage of the fact that in 1995 the Czech Republic participated in the TIMSS international survey of learning outcomes in mathematics and science, in which for the first and also the last time secondary school students were tested, including those who had taken more demanding mathematics and physics courses. The specialised physics 90-minute test was then taken by students in the final year of four-year gymnasiums in the Czech Republic. This particular physics test was administered to current gymnasium students. Gymnasium students represent the population of secondary school students who have physics instruction listed as a compulsory part of their education in the Framework Educational Programmes. Therefore, these respondents can provide very valuable information about what students take away from studying physics in primary and secondary school. The paper describes ongoing research, its methodology and how the data were collected.
Analysis of the difficulty of text generated by the ChatGPT artificial intelligence, text from a lower-secondary physics textbook, and other sources in Czech language
Authors: Vochozka Vladimír
Published: March 2024

ChatGPT (Generative Pre-trained Transformer) is a chatbot that was launched by Open AI as a prototype on November 30, 2022. ChatGPT has quickly gained attention for its detailed and well-formulated answers in many areas of knowledge. It can write computer programmes, poetry, business correspondence, or generate seemingly technical texts, depending on the verbal assignment. This article analyses and compares text in Czech language describing hydrostatic pressure produced by ChatGPT, from lower-secondary physics textbook and other sources. A text difficulty analysis was performed on the selected texts. The text-difficulty analysis by Nestler was chosen to assess the didactic properties. The results of the text-difficulty analysis and the selected partial coefficients are discussed.
Does generation Z (and Alpha) need physics as a separate school subject?
Authors: Holubova R
Published: March 2024

Physics teachers and learners collected surveys focused on their belief of teaching and learning physics at secondary and high schools. In the context of the idea of STEM education, physics cannot be replaced by another subject - science - to a sufficient extent. All the interviewed respondents agreed on this. The learning environment is now different, the position of the teacher is different too. But the aim of education is to prepare learners for the life in the 21st century and physics plays an important role. Pupils have to acquire the necessary competences, and skills for their application on the labor market at the time of the so-called fourth industrial revolution. This aim of education is essential but not negligible is their well being at schools. It is known that a crucial trend among young people is the incidence of depression and early school leaving. The outcome of our investigation has shown that in physics a lot of basic cognitive skills are taught. Physics is also a platform for buiding skills needed in the 21st century – communication, creativity, critical thinking. Physics is an essential part of STEM education. The results of the surveys were incorporated into the subjects of the pregraduate physics teacher training. The basic trend in teaching physics is quality versus quantity, the use of physics knowledge in everyday life. The way how physics teachers deal with these new objectives, which methods were chosen will be discussed in this paper.
GeoGebra and its applications - especially for teaching of geometrical optics
Authors: Kordek D , Voda P
Published: March 2024

The aim of this paper is to create two interactive electronic materials for teaching geometrical optics, especially imaging on thin lenses. Geogebra mathematical dynamic geometry software is employed for preparing the interactive constructions. In this software it is possible to work both in online mode and after installation in offline mode. There are constructs created for the software for mathematics and physics that can be used by the teacher. The paper does not describe a detailed procedure for preparing both constructions, and as an appendix we attach the original procedure for the construction as exported by the software. The reader is also introduced to the basics of geometrical optics, especially imaging on thin lenses. The values of parameters a, á and f that are measured directly by the created construction will be compared in the results with the results of these parameters, which are obtained from the derived rendering equation. In this way, we will confirm the correct function of the interactive constructions that have been created. The conclusion of the paper summarises the advantages and disadvantages of the created teaching materials.
Stimulating learning through games
Authors: Haverlíková Viera , Janiga Ladislav
Published: March 2024

Generation Z differs from its predecessors in many ways. In general, they are characterized by an emphasis on a friendly atmosphere and pragmatism. They prefer to deal with root causes, solve real-life problems and take responsibility for their decision. An educational game is a safe environment that allows students to learn by immersing themselves in solving game-challenges as well as to be responsible for their decisions and actions. The conference paper will present theoretical backgrounds and goals of the newly created subject “Educational games” offered to in-service physics teachers as an optional subject in bachelor’s degree. It was held for the first time in the academic year 2022/23, nine students took part in it. Seven of them provided feedback via an online questionnaire. Additional information was obtained from the analysis of semester papers. Expectations will be compared with experiences from the first year of the subject implementation. For most of the participants, the primary motive for participating in the course was their experience of non-formal education and the expectation of acquiring ideas for extracurricular activities. Only two students already had some idea of using the game in the physics education. Five students indicated a change in their understanding of the game as a teaching method. Possible directions for further development will be outlined.