bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study on the combined influence of particle shape, density, and size on segregation behavior in binary and ternary granular mixtures
Authors: Liao Chun-Chung , Hunt Melany L. , Sun Huang-Lin
Published: July 2024

Segregation of granular materials is a common experience; however, a few studies consider the segregation of granular mixtures characterized by variations in particle shape. Additionally, many particle systems in industry and geophysics consist of nonspherical particles. In the present study, we conducted a series of experiments to investigate the influence of particle shape, density, and size on the dynamic characteristics and segregation behavior in binary and ternary granular mixtures. Our experimental findings demonstrated a noteworthy correlation between the final steady-state segregation intensity and the proportion of non-spherical beans and cube-shaped particles in a ternary granular mixture. Specifically, the presence of beans, which are larger than the other particles, in a binary and ternary granular mixture increased the size-induced segregation phenomenon. Conversely, the steady-state segregation intensity decreased as the proportion of cube particles, which were less dense but of the same volume as the other materials, increased in a ternary granular mixture, indicating a mitigation of density-induced segregation. The study also discusses the relationship among the dynamic angle of repose, dynamic properties, and segregation behavior arising from the effects of shape, size, and density in binary and ternary granular mixtures.
Integration of Hertz–Knudsen–Schrage phase change in phase-field lattice Boltzmann method: Validation and parametric studies
Authors: Mandegari Ali , Rahimian Mohammad-Hassan , Jalali Alireza , Jafari Azadeh
Published: July 2024

The phase transition between liquid and vapor is of vital importance in daily life and industry. Given the importance of the lattice Boltzmann method (LBM), in particular the phase field method, in the simulation of two-phase flows, a robust LBM phase transition model is essential. This study introduces a novel approach by integrating the widely used, Hertz–Knudsen–Schrage (HKS) phase change rate into a conservative phase-field LBM. The phase-field and momentum equations are solved using the Boltzmann distribution function, whereas the energy equation is solved using the finite difference method. Once the necessary parameters for the calculation of the phase change rate are obtained, the corresponding source terms are incorporated into each equation. The model's validation is performed through a series of benchmark problems, including the one-dimensional Stefan problem, Nusselt's film condensation, bubble detachment, centered droplet evaporation, and sessile droplet evaporation. The results demonstrate favorable agreement between the LBM solution and analytical or empirical data. Furthermore, this study highlights the model's ability to approximate steady-state phenomena with minimal reliance on the phase change coefficient of the HKS theory. It also underscores the model's capacity to accurately capture transient phenomena by appropriately selecting values for this coefficient. In addition, parametric studies are conducted to investigate evaporation problems using the HKS theory for recognizing the effect of superheat, contact angle, and droplet size on evaporation. Finally, this model not only can detect trends and behaviors of phenomena but also can adapt empirical and analytical results with good agreement.
Band alignment engineering of 2D/3D halide perovskite lateral heterostructures
Authors: Feng Mengjia , Kong Lingkun , Chen Jinlian , Ma Huifang , Zha Chenyang , Zhang Linghai
Published: July 2024

Two-dimensional (2D)/three-dimensional (3D) halide perovskite heterostructures have been extensively studied for their ability to combine the outstanding long-term stability of 2D perovskites with the superb optoelectronic properties of 3D perovskites. While current studies mostly focus on vertically stacked 2D/3D perovskite heterostructures, a theoretical understanding regarding the optoelectronic properties of 2D/3D perovskite lateral heterostructures is still lacking. Herein, we construct a series of 2D/3D perovskite lateral heterostructures to study their optoelectronic properties and interfacial charge transfer using density functional theory (DFT) calculations. We find that the band alignments of 2D/3D heterostructures can be regulated by varying the quantum-well thickness of 2D perovskites. Moreover, decreasing the 2D component ratio in 2D/3D heterostructures can be favorable to form type-I band alignment, whereas a large component ratio of 2D perovskites tends to form type-II band alignment. We can improve the amount of charge transfer at the 2D/3D perovskite interfaces and the light absorption of 2D perovskites by increasing quantum-well thickness. These present findings can provide a clear designing principle for achieving 3D/2D perovskite lateral heterostructures with tunable optoelectronic properties.
Emergence of cooperation under punishment: A reinforcement learning perspective
Authors: Zhao Chenyang , Zheng Guozhong , Zhang Chun , Zhang Jiqiang , Chen Li
Published: July 2024

Punishment is a common tactic to sustain cooperation and has been extensively studied for a long time. While most of previous game-theoretic work adopt the imitation learning framework where players imitate the strategies of those who are better off, the learning logic in the real world is often much more complex. In this work, we turn to the reinforcement learning paradigm, where individuals make their decisions based upon their experience and long-term returns. Specifically, we investigate the prisoners’ dilemma game with a Q-learning algorithm, and cooperators probabilistically pose punishment on defectors in their neighborhood. Unexpectedly, we find that punishment could lead to either continuous or discontinuous cooperation phase transitions, and the nucleation process of cooperation clusters is reminiscent of the liquid–gas transition. The analysis of a Q-table reveals the evolution of the underlying “psychologic” changes, which explains the nucleation process and different levels of cooperation. The uncovered first-order phase transition indicates that great care needs to be taken when implementing the punishment compared to the continuous scenario.
Multiobjective optimization of porous medium for efficient transpiration cooling of hypersonic vehicles using genetic algorithm
Authors: Hoseinzade Davood , Kim Ikhyun
Published: July 2024

Transpiration cooling has been proven an effective method for reducing heat flux on the surfaces of high-speed vehicles. This study investigates the effects of porous medium properties, employing a black-box optimization method to determine the optimal length, thickness, and porosity for a porous medium in a transpiration cooling system on a flat plate under hypersonic laminar flow. The objectives include optimizing thermal effectiveness, coolant consumption, and the weight and cost of the porous material. A multiobjective genetic optimization algorithm is directly integrated with a Computational Fluid Dynamics (CFD) solver, and 1562 CFD simulations were conducted to identify the optimal configuration. The results demonstrate that the length and porosity of the porous medium more significantly impact thermal effectiveness than the thickness. Furthermore, the optimization identified a configuration for the porous medium that, when compared to the original case, shows reductions in length, thickness, and porosity of 3.5%, 11%, and 29%, respectively. Additionally, there were average improvements in thermal effectiveness and coolant consumption of 4.56% and 3.9%, respectively, while the weight and cost of the porous material increased by 3.73% and 3.65%, respectively.
The groove effect on wake characteristics of rotating cylinders
Authors: Yagmur Sercan , Aksoy Muharrem Hilmi , Dogan Sercan , Goktepeli Ilker , Ispir Murat
Published: July 2024

In the present study, active and passive flow control methods have been implemented to investigate their effects on the wake flow structures of a circular cylinder. Grooves having circular, rectangular, and triangular cross sections have been applied to the cylinders exposed to the rotation rates, α, from 0 to 0.79. The experiments have been conducted by particle image velocimetry at a Reynolds number of Re = 5 × 103. The contour graphics of time-averaged results have been presented. Moreover, the variations in velocity profiles have also been depicted. The experimental results revealed significant variations for flow patterns, wake structures, and turbulence parameters due to the effects of both groove geometries and rotational motion. In the stationary cases, for turbulence intensity, the circular grooved cylinder exhibited a 15% increase, while the triangular grooved cylinder showed a slightly higher increase of around 20% compared to that of the bare cylinder (BC). Conversely, in non-stationary cases, the rectangular grooved cylinder displayed the most prominent reduction in turbulence intensity, decreasing by approximately 10% compared to that of the BC. The groove type has considerably affected the flow structures of the wake regions, especially for the lower rotation rates.
Spin reorientation in premartensite and austenite Ni–Mn–Ga
Authors: Perevertov Alexej , Colman Ross H. , Heczko Oleg
Published: July 2024

The premartensite state of Ni–Mn–Ga magnetic shape memory alloy, sometimes called the martensite precursor state, was studied by careful and detailed measurement of the evolution of magnetization curves of magnetically closed samples to evidence local symmetry breaking. During the heating cycle after the martensite transformation, the magnetization loop slowly transforms from a typical sigmoidal shape, corresponding to the magnetization along the easy axis, to a constricted loop indicative of magnetization along a harder magnetic axis. These changes are explained by a switching of the macroscopic magnetic easy axis from [100] to [110]. Above the premartensite transformation temperature, the magnetic easy axis slowly changes back to [100]. After cooling the sample, starting at the Curie temperature, the process reverses.
MolSym: A Python package for handling symmetry in molecular quantum chemistry
Authors: Goodlett Stephen M. , Kitzmiller Nathaniel L. , Turney Justin M. , Schaefer Henry F.
Published: July 2024

A consideration of the point group symmetry of molecules is often advantageous from a computational efficiency standpoint and sometimes necessary for the correct treatment of chemical physics problems. Many modern electronic structure software packages include a treatment of symmetry, but these are sometimes incomplete or unusable outside of that program’s environment. Therefore, we have developed the MolSym package for handling molecular symmetry and its associated functionalities to provide a platform for including symmetry in the implementation and development of other methods. Features include point group detection, molecule symmetrization, arbitrary generation of symmetry element sets and character tables, and symmetry adapted linear combinations of real spherical harmonic basis functions, Cartesian displacement coordinates, and internal coordinates. We present some of the advantages of using molecular symmetry as achieved by MolSym, particularly with respect to Hartree–Fock theory, and the reduction of finite difference displacements in gradient/Hessian computations. This package is designed to be easily integrated into other software development efforts and may be extended to further symmetry applications.
Influences of the vibration frequency and phase of the core of ultra-high voltage shunt reactors on suspended discharge in oil-paper insulation
Authors: Yu Hua , Liu Hong , Li Shuai , Liang Jizhong , Niu Shu
Published: July 2024

Severe vibration of the core of ultra-high voltage (UHV) shunt reactors under operating conditions often leads to the occurrence of suspension electrode, and such a suspended discharge defect will destroy the oil-paper insulation. It is necessary to investigate the influence of vibration on suspended discharge when determining the best operating condition of UHV shunt reactors. The vibration frequency of the suspension electrode and the phase difference between the applied voltage and the vibration are studied by simulation and experiment. The simulation results show that the phase difference between the voltage and the vibration parameters will lead to an increase in the surface maximum field strength. The distortion of the field intensity caused by several typical vibration frequencies of reactor vibration is ranked (in ascending order) thus: 100, 300, 50, and 200 Hz. There is a coupling relationship between the phase difference and the vibration frequency on the suspended discharge, which will lead to an inconsistency between the field intensity and each single factor. The partial discharge test results of the collision between the suspension electrode and the high-voltage electrode show that the discharge generated by vibration at 100 Hz is much higher than that at other frequencies, followed by those at 300 and 50 Hz, and the discharge generated by vibration at 200 Hz is very small. When the phase difference of voltage advance vibration is between 0° and 90°, the quantity of local discharge is large. When the phase difference is between 90° and 180°, the local discharge is small.
Impact of dimensionality on the magnetocaloric effect in two-dimensional magnets
Authors: Patra Lokanath , Quan Yujie , Liao Bolin
Published: July 2024

Magnetocaloric materials, which exploit reversible temperature changes induced by magnetic field variations, are promising for advancing energy-efficient cooling technologies. The potential integration of two-dimensional materials into magnetocaloric systems represents an emerging opportunity to enhance the magnetocaloric cooling efficiency. In this study, we use atomistic spin dynamics simulations based on first-principles parameters to systematically evaluate how magnetocaloric properties transition from three-dimensional (3D) to two-dimensional (2D) ferromagnetic materials. We find that 2D features such as reduced Curie temperature, sharper magnetic transition, and higher magnetic susceptibility are beneficial for magnetocaloric applications, while the relatively higher lattice heat capacity in 2D can compromise achievable adiabatic temperature changes. We further propose GdSi2 as a promising 2D magnetocaloric material. Our calculation predicts that GdSi2 exhibits an isothermal entropy change ΔSM of 22.5 J kg−1 K−1 and an adiabatic temperature change ΔTad of 6.2 K, near the hydrogen liquefaction temperature (TC≈25 K). Our analysis offers valuable theoretical insights into the magnetocaloric effect in 2D ferromagnets and demonstrates that 2D ferromagnets hold promise for cooling and thermal management applications in compact and miniaturized nanodevices.
On possibility of anomalous microwave power absorption and gyrotron frequency sub-harmonics emission in X2-mode ECRH experiments at the TCV tokamak
Authors: Popov A. Yu. , Gusakov E. Z.
Published: July 2024

In this paper, we analyze theoretically the low-threshold parametric decay instability (PDI) that can be excited at the tokamak à configuration variable (TCV tokamak, Lausanne, Switzerland) during X2 electron cyclotron resonance heating experiments producing a two-dimensionally localized upper hybrid (UH) wave and a daughter extraordinary wave running from the decay layer outward to the plasma edge. The primary instability is then saturated due to the cascade of secondary decays into two-dimensionally localized UH and ion Bernstein waves. The level of plasma microwave emission in the frequency range substantially below half the pump wave frequency and of anomalous power losses of the pump are predicted.
Voltage-insensitive stochastic magnetic tunnel junctions with double free layers
Authors: Ota Rikuto , Kobayashi Keito , Hayakawa Keisuke , Kanai Shun , Çamsarı Kerem Y. , Ohno Hideo , Fukami Shunsuke
Published: July 2024

Stochastic magnetic tunnel junction (s-MTJ) is a promising component of probabilistic bit (p-bit), which plays a pivotal role in probabilistic computers. For a standard cell structure of the p-bit, s-MTJ is desired to be insensitive to voltage across the junction over several hundred millivolts. In conventional s-MTJs with a reference layer having a fixed magnetization direction, however, the stochastic output significantly varies with the voltage due to spin-transfer torque (STT) acting on the stochastic free layer. In this work, we study a s-MTJ with a “double-free-layer” design theoretically proposed earlier, in which the fixed reference layer of the conventional structure is replaced by another stochastic free layer, effectively mitigating the influence of STT on the stochastic output. We show that the key device property characterized by the ratio of relaxation times between the high- and low-resistance states is one to two orders of magnitude less sensitive to bias voltage variations compared to conventional s-MTJs when the top and bottom free layers are designed to possess the same effective thickness. This work opens a pathway for reliable, nanosecond-operation, high-output, and scalable spintronics-based p-bits.
A method for obtaining the starting set of formation based on IPSO
Authors: Li Yan , Yi Li , Miao Yao , Pu Yu , Peng Yang
Published: July 2024

The formation of intelligent platforms is a multi-objective constraint problem. It is necessary for the multi-agent to automatically generate the path from the initial position to the specified end point, and at the same time meet the constraints of space collision avoidance on the multi-target intersection path and the constraint of the agent’s motion ability, and pursue the shortest formation time of the whole formation as much as possible. In this paper, we propose an improved method for obtaining the starting set of multi-agent formation based on particle swarm optimization. First, the starting point set of the formation is defined, and then the particle swarm optimization algorithm is selected as the optimization algorithm to find the best starting point of the formation. Then the turning performance of the intelligent platform is studied, and the assembly route of each agent is designed by combining the Dubins curve. The simulation results show that the proposed method avoids collision between agents, shortens the time of agent formation assembly, and effectively ensures the reliability of the assembly route.
Plant life-history data as evidence of an historical mixed-severity fire regime in Banksia Woodlands
Authors: Miller Russell G. , Enright Neal J. , Fontaine Joseph B. , Merritt David J. , Miller Ben P.
Published: July 2024

Context The concept of the fire regime is central to understanding and managing fire-prone ecosystems globally, and information on past regimes can provide useful insights into species disturbance adaptations. Although observations from satellite imagery or palaeoecological proxy data can provide direct evidence of past, pre-colonial fire regimes, they may be limited in temporal or spatial resolution and are not available for all ecosystems. However, fire-related plant-trait and demographic data offer an alternative approach to understand species–fire regime associations at the ecosystem scale. Aims We aimed to quantify the life-history strategies and associated fire regimes for six co-occurring shrub and tree species from fire-prone, Mediterranean-climate Banksia Woodlands in south-western Australia. Methods We collected static demographic data on size structure, seedling recruitment, and plant mortality across sites of varying time since last fire. We combined demographic data with key fire-related species traits to define plant life-history strategies. We then compared observed life histories with a priori expectations for surface, stand-replacing, and mixed-severity fire-regime types to infer historical fire-regime associations. Key results Fire-killed shrubs and weakly serotinous trees had abundant post-fire seedling recruitment, but also developed multi-cohort populations during fire-free periods via inter-fire seedling recruitment. Resprouting shrubs had little seedling recruitment at any time, even following fire, and showed no signs of decline in the long absence of fire, likely owing to their very long lifespans. Conclusions The variation in life-history strategies for these six co-occurring species is consistent with known ecological strategies to cope with high variation in fire intervals in a mixed-severity fire regime. Whereas resprouting and strong post-fire seedling recruitment indicate a tolerance of shorter fire intervals, inter-fire recruitment and weak serotiny are interpreted as a bet-hedging strategy to cope with occasional long fire-free periods that may otherwise exceed adult and seed-bank lifespans. Implications Our findings suggested that Banksia Woodlands have evolved with highly variable fire intervals in a mixed-severity fire regime. Further investigations of species adaptations to varying fire size and patchiness can help extend our understanding of fire-regime tolerances.
Heliotropium thermophilum adapts to high soil temperature in natural conditions due to its highly active antioxidant system protecting its photosynthetic machinery
Authors: Bülbül Sevgi , Sezgin Muslu Asiye , Sağlam Aykut , Kadıoğlu Asim
Published: July 2024

Heliotropium thermophilum (Boraginaceae) plants have strong antioxidant properties. This study investigated the effectiveness of the antioxidant system in protecting the photosynthetic machinery of H. thermophilum. Plants were obtained from Kızıldere geothermal area in Buharkent district, Aydın, Turkey. Plants in the geothermal area that grew at 25–35°C were regarded as the low temperature group, while those that grew at 55–65°C were regarded as the high temperature group. We analysed the physiological changes of these plants at the two temperature conditions at stage pre-flowering and flowering. We meaured the effect of high soil temperature on water potential, malondialdehyde, cell membrane stability, and hydrogen peroxide analysis to determine stress levels on leaves and roots. Changes in antioxidant enzyme activities, ascorbate and chlorophyll content, chlorophyll fluorescence, photosynthetic gas exchange parameters, and photosynthetic enzymes (Rubisco and invertase) activities were also determined. Our results showed minimal changes to stress levels, indicating that plants were tolerant to high soil temperatures. In general, an increase in antioxidant enzyme activities, ascorbat levels, and all chlorophyll fluorescence parameters except for non-photochemical quenching (NPQ) and Fv/Fm were observed. The pre-flowering and flowering stages were both characterised by decreased NPQ, despite Fv/Fm not changing. Additionally, there was a rise in the levels of photosynthetic gas exchange parameters, Rubisco, and invertase activities. High temperature did not affect photosynthetic yield because H. thermophilum was found to stimulate antioxidant capacity, which reduces oxidative damage and maintains its photosynthetic machinery in high temperature conditions and therefore, it is tolerant to high soil temperature.
An HSF1–JMJD6–HSP feedback circuit promotes cell adaptation to proteotoxic stress
Authors: Alasady Milad J. , Koeva Martina , Takagishi Seesha R. , Segal Dmitri , Amici David R. , Smith Roger S. , Ansel Daniel J. , Lindquist Susan , Whitesell Luke , Bartom Elizabeth T. , Taipale Mikko , Mendillo Marc L.
Published: July 2024

Heat Shock Factor 1 (HSF1) is best known as the master transcriptional regulator of the heat-shock response (HSR), a conserved adaptive mechanism critical for protein homeostasis (proteostasis). Combining a genome-wide RNAi library with an HSR reporter, we identified Jumonji domain-containing protein 6 (JMJD6) as an essential mediator of HSF1 activity. In follow-up studies, we found that JMJD6 is itself a noncanonical transcriptional target of HSF1 which acts as a critical regulator of proteostasis. In a positive feedback circuit, HSF1 binds and promotes JMJD6 expression, which in turn reduces heat shock protein 70 (HSP70) R469 monomethylation to disrupt HSP70–HSF1 repressive complexes resulting in enhanced HSF1 activation. Thus, JMJD6 is intricately wired into the proteostasis network where it plays a critical role in cellular adaptation to proteotoxic stress.
STING trafficking activates MAPK–CREB signaling to trigger regulatory T cell differentiation
Authors: Lin Wei , Szabo Claudia , Liu Tao , Tao Huangheng , Wu Xianfang , Wu Jianjun
Published: July 2024

The Type-I interferon (IFN-I) response is the major outcome of stimulator of interferon genes (STING) activation in innate cells. STING is more abundantly expressed in adaptive T cells; nevertheless, its intrinsic function in T cells remains unclear. Intriguingly, we previously demonstrated that STING activation in T cells activates widespread IFN-independent activities, which stands in contrast to the well-known STING-mediated IFN response. Here, we have identified that STING activation induces regulatory T cells (Tregs) differentiation independently of IRF3 and IFN. Specifically, the translocation of STING from the endoplasmic reticulum to the Golgi activates mitogen-activated protein kinase (MAPK) activity, which subsequently triggers transcription factor cAMP response element-binding protein (CREB) activation. The activation of the STING–MAPK–CREB signaling pathway induces the expression of many cytokine genes, including interleukin-2 (IL-2) and transforming growth factor-beta 2 (TGF-β2), to promote the Treg differentiation. Genetic knockdown of MAPK p38 or pharmacological inhibition of MAPK p38 or CREB markedly inhibits STING-mediated Treg differentiation. Administration of the STING agonist also promotes Treg differentiation in mice. In the

Trex1
−/−

autoimmune disease mouse model, we demonstrate that intrinsic STING activation in CD4+ T cells can drive Treg differentiation, potentially counterbalancing the autoimmunity associated with
Trex1
deficiency. Thus, STING–MAPK–CREB represents an IFN-independent signaling axis of STING that may have profound effects on T cell effector function and adaptive immunity.
IFIH1 (MDA5) is required for innate immune detection of intron-containing RNA expressed from the HIV-1 provirus
Authors: Guney Mehmet Hakan , Nagalekshmi Karthika , McCauley Sean Matthew , Carbone Claudia , Aydemir Ozkan , Luban Jeremy
Published: July 2024

Intron-containing RNA expressed from the HIV-1 provirus activates type 1 interferon in primary human blood cells, including CD4
+
T cells, macrophages, and dendritic cells. To identify the innate immune receptor required for detection of intron-containing RNA expressed from the HIV-1 provirus, a loss-of-function screen was performed with short hairpin RNA-expressing lentivectors targeting twenty-one candidate genes in human monocyte-derived dendritic cells. Among the candidate genes tested, only knockdown of XPO1 (CRM1), IFIH1 (MDA5), or MAVS prevented activation of the interferon-stimulated gene ISG15. The importance of IFIH1 protein was demonstrated by rescue of the knockdown with nontargetable IFIH1 coding sequence. Inhibition of HIV-1-induced ISG15 by the IFIH1-specific Nipah virus V protein, and by IFIH1-transdominant 2-CARD domain-deletion or phosphomimetic point mutations, indicates that IFIH1 (MDA5) filament formation, dephosphorylation, and association with MAVS are all required for innate immune activation in response to HIV-1 transduction. Since both IFIH1 (MDA5) and DDX58 (RIG-I) signal via MAVS, the specificity of HIV-1 RNA detection by IFIH1 was demonstrated by the fact that DDX58 knockdown had no effect on activation. RNA-Seq showed that IFIH1 knockdown in dendritic cells globally disrupted the induction of IFN-stimulated genes by HIV-1. Finally, specific enrichment of unspliced HIV-1 RNA by IFIH1 (MDA5), over two orders of magnitude, was revealed by formaldehyde cross-linking immunoprecipitation (f-CLIP). These results demonstrate that IFIH1 is the innate immune receptor for intron-containing RNA from the HIV-1 provirus and that IFIH1 potentially contributes to chronic inflammation in people living with HIV-1, even in the presence of effective antiretroviral therapy.
Improving phytosanitary trade compliance in Bangladesh. Life of project report - 01.01.2021 to 09.30.2022
Authors: Khetarpal Ravinder Kumar ,   APAARI, 182 Lan Luang Rd, Khlong Mahanak, Pomprab Sattrupai, Bangkok 10100, Thailand
Published: July 2024

The USDA's Trade and Regulatory Capacity Building Division (TRCBD) partnered with APAARI to assist Bangladesh's Department of Agricultural Extension (DAE) in improving compliance with international phytosanitary standards under the project "Improving Phytosanitary and Trade Compliance in Bangladesh," initiated on 23 November 2020. The project aimed to enhance collaboration among stakeholders, strengthen the institutional capacity of Bangladesh's NPPO, raise awareness on trade-related issues and promote regulatory harmonization for biopesticide registration. Key achievements from November 2020 to September 2022 included establishment of the intradepartmental community on plant quarantine facilitation within DAE, formation of a steering committee co-chaired by USDA and DAE officials and development of 3 standard operating procedures for pest management. Public awareness was increased through various media channels, and a WhatsApp group was created for SPS stakeholders. Amendments to the Plant Quarantine Act were proposed and reviewed with input from legal and technical experts. The project also established a virtual SPS training hub and conducted 17 capacity-building programs, including technical training on various phytosanitary subjects and workshops on biopesticide regulatory harmonization. Despite challenges due to the COVID-19 pandemic and issues beyond the project's control, significant progress was made, contributing to the overall success of the initiative.
Supporting laboratories in physics education with virtual experiments videos
Authors: Velentzas Athanasios , Dimakopoulou Alkisti , Theodonis Ioannis
Published: July 2024

This paper introduces a pragmatic educational proposal for the integration of virtual experiments (VEs) in physics education. The challenges in physics education posed by the COVID-19 pandemic led to the creation of 20 VEs, meeting criteria of rapid development, zero financial cost, and alignment with educational goals. Implemented during and post quarantine time, VEs effectively supported students’ remote laboratory practice. Also, the data analysis of the present study suggests that the proposed approach, adaptable and cost-effective, not only supports distance learning but also proves valuable in tandem with real experiments in traditional physics laboratory education as a preperative procedure. Teachers’ positive feedback underscores the proposal’s educational benefits, emphasizing its potential for sustained integration beyond quarantine conditions.
Polarized Raman, infrared and dielectric spectra of lead-free K0.5Na0.5NbO3 piezoelectric system: insights from ab-initio theoretical and experimental studies
Authors: Saha Manish , Niranjan Manish K , Asthana Saket
Published: July 2024

The K0.5Na0.5NbO3 (KNN) system has emerged as one of the most promising lead-free piezoelectric over the years. In this work, we perform a comprehensive investigation of electronic structure, lattice dynamics and dielectric properties of room temperature phase of KNN by combining ab-initio DFT based theoretical analysis and experimental characterization. We assign the symmetry labels to KNN vibrational modes and obtain ab-initio polarized Raman spectra, Infrared reflectivity, Born-effective charge tensors, oscillator strengths etc. The KNN ceramic samples are prepared using conventional solid-state method and Raman and UV–Vis diffuse reflectance spectra are obtained. The computed Raman spectrum is found to agree well with the experimental spectrum. In particular, the results suggest that the mode in range ∼840–870 cm−1 reported in the experimental studies is longitudinal optical with

A
1

symmetry. The Raman mode intensities are calculated for different light polarization set-ups that suggests the observation of different symmetry modes in different polarization set-ups. The electronic structure of KNN is investigated and optical absorption spectrum is obtained. Further, the performances of DFT semi-local, meta-GGA and hybrid exchange-correlations functionals, in the estimation of KNN band gaps are investigated. The KNN bandgap computed using GGA-1/2 and HSE06 hybrid functional schemes are found to be in excellent agreement with the experimental value. The COHP, electron localization function and Bader charge analysis is also performed to deduce the nature of chemical bonding in the KNN. Overall, our study provides several bench-mark important results on KNN that have not been reported so far.
Decoupling the rheological responses of a soft solid emulsion with liquid inclusions
Authors: Gilbert E , Salonen A , Poulard C
Published: July 2024

Soft solid emulsions are liquid droplets encapsulated in a soft solid material. Typical of dispersed systems, they can combine properties from both the liquid inclusions and the soft solids. The relative importance of the two phases in the rheological response is captured through the elastocapillary number, which compares capillary forces in the liquid inclusions to the matrix rigidity. We work with solid emulsions formed of poly(ethylene glycol) droplets in a poly(dimethylsiloxane) (PDMS) continuous phase. We create three families of emulsions with varying elastocapillary numbers, and range of inclusion volume fractions from 0 to 0.5. Through oscillatory rheology we probe both the elastic response and the dissipative effects of liquid droplets. In the case of a dominant response from the continuous phase or the drops, the results can be described with Palierne’s model. However, for the intermediate elastocapillary series we show that the evolution of the storage and loss moduli decouple with dispersed phase volume fraction. We attribute the increase of loss factor with volume fraction to the high polydispersity in droplet size. We can further modulate the response of the materials by cooling to freeze the droplets. This approach allows us to compare these soft solid emulsions with theories related to solid dispersions.
An event-triggered background-oriented schlieren technique combined with dynamic projection using dynamic mirror device
Authors: Lyu Zhen , Cai Weiwei , Liu Yingzheng
Published: July 2024

This paper reports a high-frequency event-triggered background-oriented schlieren (BOS) technique using a combination of an event-triggered camera and dynamic projection. To combine the advantages of continuous and pulsed illumination for the event-triggered camera, a novel background pattern is first developed to incorporate static and dynamic textures generated through projection utilizing a dynamic mirror device. Then, a specific post-processing algorithm is proposed to reconstruct frames with high time accuracy from event data. This technique allows for the continuous observation and capturing of flows at 4000 frames per second (FPS) with a very low cost, breaking through the short operating times of current high-frame-rate BOS. Moreover, the proposed BOS technique can visualize the flow in real-time with high temporal accuracy, a capability that is challenging to achieve with traditional BOS. To examine the proposed technique, BOS experiments were conducted on a sweeping jet actuator with various inlet pressure. The sweeping dynamics and the start-up process of the sweeping jet at various inlet pressure were visualized and investigated. It is found that the proposed event-triggered BOS can continuously visualize and record the jet flow at a resolution of 1280 × 720 pixels with an equivalent frame rate of up to 4000 FPS. The oscillation frequency of the sweeping jet was found to increase linearly with increasing inlet pressure. It reaches 117.2 Hz at an inlet pressure of 0.5 Mpa. Within the first 10 ms or so of start-up, the shape of the sweep was found to be symmetrical. Within the next 100 ms, the jet commences to sweep and saturates. The start-up time of the sweeping jet was quantitatively measured and was observed to decrease with increased inlet pressures.
Full-scale testing and multiphysics modeling of a reinforced shot-earth concrete vault with self-sensing properties
Authors: D’Alessandro Antonella , Meoni Andrea , Romero Rubén Rodríguez , García-Macías Enrique , Viviani Marco , Ubertini Filippo
Published: July 2024

Civil constructions significantly contribute to greenhouse gas emissions and entail extensive energy and resource consumption, leading to a substantial ecological footprint. Research into eco-friendly engineering solutions is therefore currently imperative, particularly to mitigate the impact of concrete technology. Among potential alternatives, shot-earth-concrete, which combines cement and earth as a binder matrix and is applied via spraying, emerges as a promising option. Furthermore, this composite material allows for the incorporation of nano and micro-fillers, thereby providing room for enhancing mechanical properties and providing multifunctional capabilities. This paper investigates the damage detection capabilities of a novel smart shot-earth concrete with carbon microfibers, by investigating the strain sensing performance of a full-scale vault with a span of 4 m, mechanically tested until failure. The material’s strain and damage sensing capabilities involve its capacity to produce an electrical response (manifested as a relative change in resistance) corresponding to the applied strain in its uncracked state, as well as to exhibit a significant alteration in electrical resistance upon cracking. A detailed multiphysics numerical (i.e. mechanical and electrical) model is also developed to aid the interpretation of the experimental results. The experimental test was conducted by the application of an increasing vertical load at a quarter of the span, while modelling of the element was carried out by considering a piezoresistive material, with coupled mechanical and electrical constitutive properties, including a new law to reproduce the degradation of the electrical conductivity with tensile cracking. Another notable aspect of the simulation was the consideration of the effects of the electrical conduction through the rebars, which was found critical to accurately reproduce the full-scale electromechanical response of the vault. By correlating the outcomes from external displacement transducers with the self-monitoring features inherent in the proposed material, significant insights were gleaned. The findings indicated that the proposed smart-earth composite, besides being well suited for structural applications, also exhibits a distinctive electromechanical behavior that enables the early detection of damage initiation. The results of the paper represent an important step toward the real application of smart earth-concrete in the construction field, demonstrating the effectiveness and feasibility of full-scale strain and damage monitoring even in the presence of steel reinforcement.
Recent advances of doping strategy for boosting the electrocatalytic performance of two-dimensional noble metal nanosheets
Authors: Wei Zebin , Shen Yongqing , Wang Xudong , Song Yanhui , Guo Junjie
Published: July 2024

Benefiting from the ultrahigh specific surface areas, massive exposed surface atoms, and highly tunable microstructures, the two-dimensional (2D) noble metal nanosheets (NSs) have presented promising performance for various electrocatalytic reactions. Nevertheless, the heteroatom doping strategy, and in particular, the electronic structure tuning mechanisms of the 2D noble metal catalysts (NMCs) yet remain ambiguous. Herein, we first review several effective strategies for modulating the electrocatalytic performance of 2D NMCs. Then, the electronic tuning effect of hetero-dopants for boosting the electrocatalytic properties of 2D NMCs is systematically discussed. Finally, we put forward current challenges in the field of 2D NMCs, and propose possible solutions, particularly from the perspective of the evolution of electron microscopy. This review attempts to establish an intrinsic correlation between the electronic structures and the catalytic properties, so as to provide a guideline for designing high-performance electrocatalysts.
Surface-enhanced Raman scattering nanotag of tunable ZIF-8 shell-encapsulated magnetic core-plasmonic satellites for disentangling chemical enhancement from electromagnetic enhancement
Authors: Chen Hao , Wu ZhaoGuo , Zhao AiWu , Wang Jin
Published: July 2024

To enhance the stability of Raman reporters, these reporters were trapped in a metal organic framework (MOF) exoskeleton that was grown and compressed on Fe3O4@Au core–satellites, producing recyclable surface-enhanced Raman scattering (SERS) nanotags. Furthermore, encapsulation of Raman reporters in the assembled MOF-based nanocomposites was divided into two types of patterns, pre-enrichment and post-enrichment, in order to disentangle chemical enhancement of charge transfer (CT) from electromagnetic enhancement (EM) in SERS. Hence, to demonstrate the effect of encapsulation, a typical non-thiolated Raman reporter, for example crystal violet (CV) trapped in a core–satellite nanoassembly-based zeolitic imidazolate framework (ZIF-8) shell, was selected. The results suggest that stability and Raman intensity are remarkably improved. Moreover, the pattern of incorporation of CV into the ZIF-8 shell with tunable shell thickness can contribute to the disentangling of CT effects from EM effects.
Research of single-event burnout in vertical Ga2O3 FinFET by low carrier lifetime control
Authors: Bao Yun-can , Yu Cheng-hao , Zhao Wen-sheng , Wu Xiao-dong , Tan Xin , Yang Hui
Published: July 2024

This paper presents the 2D simulations of single-event burnout (SEB) in vertical enhancement-mode gallium oxide (Ga2O3) fin-shaped channels field-effect transistor (FinFET) by low carrier lifetime control (LCLC) method. The correctness of the structure parameters and simulated physical models are verified by the basic electrical characteristics in experiments. The SEB simulations show that the most sensitive region to heavy ion is the narrow channel region. The SEB failure is due to the diffusion of a large number of electron–hole pairs induced by heavy ion into a strong electric field region, resulting in a large transient current density to cause the thermal failure. Afterwards, the influences of the narrow channel region width on basic characteristics and SEB performance are discussed. Then, the SEB hardening mechanism of LCLC is studied that the electric field peak in the top of the structure can be effectively reduced, and the transient current caused by second avalanche is restrained. In addition, the basic characteristics with LCLC are proved to be hardly influenced in Ga2O3 FinFET. Finally, the carrier lifetime value and local control region are studied that the SEB hardening performance can be significantly improved by a large enough control area with a low carrier lifetime.
Soft lenses with large focal length tuning range based on stacked PVC gel actuators
Authors: Zhang Chi , Qin Jianguo , Gao Yuan , Cao Leilei , Liu Xuejing , Zhu Zicai
Published: July 2024

A novel tunable lens with large focal length change and driven by stacked polyvinyl chloride (PVC) gel actuators is designed and characterized in this study. The lens rigid parts are 3D-printed and commercially available, whereas the PVC gel membrane is in volume production. Under electrical actuation, the lens attains focal length ranges from 30 to 217 mm within 400 V. A manual regulating mechanism is proposed for the finished lens that dexterously adjusts the initial focus and focal length ranges. In the compound actuation mode, large focus variation over 950% is achieved within 250 V. Under 250 V step input, the lens exhibits practical response time around 291 ms. Focal length tuning ability of the lens is also demonstrated by capturing the images of objects placed in different positions. This tunable lens is promising for various smart optics.
Doppler-enhanced quantum magnetometry with thermal Rydberg atoms
Authors: Barik Shovan Kanti , S Silpa B , Ramana M Venkat , Dutta Shovan , Roy Sanjukta
Published: July 2024

We report experimental measurements showing how one can combine quantum interference and thermal Doppler shifts at room temperature to detect weak magnetic fields. We pump

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Rb atoms to a highly-excited, Rydberg level using a probe and a coupling laser, leading to narrow transmission peaks of the probe due to destructive interference of transition amplitudes, known as Electromagnetically Induced Transparency. While it is customary in such setups to use counterpropagating lasers to minimize the effect of Doppler shifts, here we show, on the contrary, that one can harness Doppler shifts in a copropagating arrangement to produce an enhanced response to a magnetic field. In particular, we demonstrate an order-of-magnitude bigger splitting in the transmission spectrum as compared to the counterpropagating case. We explain and generalize our findings with theoretical modeling and simulations based on a Lindblad master equation. Our results pave the way to using quantum effects for magnetometry in readily deployable room-temperature platforms.
Quasiparticles-mediated thermal diode effect in Weyl Josephson junctions
Authors: Chatterjee Pritam , Dutta Paramita
Published: July 2024

We theoretically show quasiparticles-driven thermal diode effect (TDE) in an inversion symmetry-broken Weyl superconductor (WSC)-Weyl semimetal (WSM)-WSC Josephson junction. A Zeeman field perpendicular to the WSM region of the thermally-biased Weyl Josephson junction (WJJ) induces an asymmetry between the forward and reverse thermal currents, which is responsible for the TDE. Most interestingly, we show that the sign and magnitude of the thermal diode rectification coefficient is highly tunable by the superconducting phase difference and external Zeeman field, and also strongly depends on the junction length. The tunability of the rectification, particularly, the sign changing behavior associated with higher rectification enhances the potential of our WJJ thermal diode to use as functional switching components in thermal devices.
The effect of the electron κ-distribution on the dust particle charging in the radio-frequency thermal-sheaths
Authors: Shihab M , Elkamash I S
Published: July 2024

In order to investigate collisionless radiofrequency plasma sheaths containing dust particles, three models are utilized: the novel kinetic scheme Ensemble-in-Spacetime (EST) model for calculating sheath parameters, the Dust Particle Charging model, and the Single Dust Particle model. The EST model has been modified to account for κ-electron distributions. This model is applicable to radiofrequency plasma sheaths found in tokamaks equipped with an ion cyclotron radiofrequency (ICRF) wave heating system, such as JET, West(Tore Supra), EAST, ASDEX-U, and KSTAR. The calculated sheath parameters are utilized to determine the electron and ion currents of the dust particles. In the intermediate radio-frequency regime, when the ion plasma frequency is comparable to the ICRF, the flux and energy of the ions are modulated in time within the sheath. The ions are not inertialess, and the value of κ affects the electron and ion densities. As the value of κ increases, the time-averaged electron and ion densities, sheath edge position, and area of the sheath voltage-sheath charge hysteresis loop also increase. However, the ion energy distribution remains insensitive to the κ distribution. The dust particles are charged with different negative charges based on their radius, position within the sheath, κ-electron distribution, and sheath potential. These particles exhibit oscillatory motion due to their interactions with the plasma and gravitational fields and are accelerated toward the plasma core.