bluuebunny/crossref_metadata_2025 huggingface dataset:
Thickness dependent OER electrocatalysis of epitaxial thin film of high entropy oxide
Authors: Patel Ranjan Kumar , Jenjeti Ramesh Naidu , Kumar Rajat , Bhattacharya Nandana , Kumar Siddharth , Ojha Shashank Kumar , Zhang Zhan , Zhou Hua , Qu Ke , Wang Zhen , Yang Zhenzhong , Klewe Christoph , Shafer Padraic , Sampath S. , Middey Srimanta
Published: August 2023

High entropy oxides (HEOs), which contain multiple elements in the same crystallographic site, are a promising platform for electrocatalysis in oxygen evolution reaction (OER). Investigating these materials in epitaxial thin film form expands the possibility of tuning OER activity by several means, which are not realizable in polycrystalline samples. To date, very few such studies have been reported. In this work, the OER activity of single-crystalline thin films of (La0.2Pr0.2Nd0.2Sm0.2Eu0.2)NiO3, grown on NdGaO3 substrates have been investigated in 0.1 M KOH electrolyte as a function of film thickness. The OER activity increases with the thickness of the film. X-ray absorption spectroscopy measurements find an increase in Ni d-O p covalency and a decrease in charge transfer energy with the increase in film thickness. These facilitate higher charge transfer between Ni and surface adsorbates, increasing OER activity. However, the OER process leads to excessive leaching of thicker films and the OER activity of a 75 unit cell thick film is found to be optimal in the present study. This work demonstrates that the thickness of perovskite oxides can be used as a parameter to enhance OER activity.
Uncoupling system and environment simulation cells for fast-scaling modeling of complex continuum embeddings
Authors: Medrano G. , Bainglass E. , Andreussi O.
Published: August 2023

Continuum solvation models are becoming increasingly relevant in condensed matter simulations, allowing to characterize materials interfaces in the presence of wet electrified environments at a reduced computational cost with respect to all atomistic simulations. However, some challenges with the implementation of these models in plane-wave simulation packages still persists, especially when the goal is to simulate complex and heterogeneous environments. Among these challenges is the computational cost associated with large heterogeneous environments, which in plane-wave simulations has a direct effect on the basis-set size and, as a result, on the cost of the electronic structure calculation. Moreover, the use of periodic simulation cells is not well-suited for modeling systems embedded in semi-infinite media, which is often the case in continuum solvation models. To address these challenges, we present the implementation of a double-cell formalism, in which the simulation cell used for the continuum environment is uncoupled from the one used for the electronic-structure simulation of the quantum-mechanical system. This allows for a larger simulation cell to be used for the environment, without significantly increasing computational time. In this work, we show how the double-cell formalism can be used as an effective periodic boundary conditions correction scheme for nonperiodic and partially periodic systems. The accuracy of the double-cell formalism is tested using representative examples with different dimensionalities, both in vacuum and in a homogeneous continuum dielectric environment. Fast convergence and good speedups are observed for all the simulation setups, provided the quantum-mechanical simulation cell is chosen to completely fit the electronic density of the system.
Pressure-driven structural transition in CoNi-based multi-principal element alloys
Authors: Li R. , Yu P. F. , Yang H. , Jiang M. H. , Yu S. B. , Huo C. , Liu X. S. , Li G.
Published: August 2023

Pressure-driven phase transition in metals has been a hot topic because it is an effective means to induce fresh phase, benefit of tuning the properties of materials. Herein, CoNiFe, CoNiCr, and CoNiV multi-principal element alloys (MPEAs) were investigated by an in situ high-pressure x-ray diffraction technique. It is found that the pressure-induced phase transition from face-centered cubic to hexagonal close-packed phase occurs at 15.60, 13.84, and 8.20 GPa, respectively. The atomic size misfit of CoNiFe, CoNiCr, and CoNiV MPEAs is estimated to be 0.653%, 2.077%, and 3.013%, respectively, illustrating that the lattice distortion degree is increasing. The increase in lattice distortion can decrease the initial phase-transition-pressure because lattice distortion could reduce the strain to nucleate Shockley partial dislocation, which promotes the formation of a stacking fault (SF) stack of three atomic layers with hcp stacking. However, the quantitative calculation of stacking fault probability α as a function of pressure demonstrates that the probability of SF formation gradually increases in order of CoNiFe, CoNiCr, and CoNiV, which is in line with the critical pressure of phase transition decreasing orderly. Furthermore, the first peak in the pair distribution function curve after entirely decompression not fully reverts to its initial state, proving the densification of MPEAs under pressure. These findings provide an innovative light for understanding pressure-induced phase transitions in MPEAs.
Simulation and validation studies of a large drift tube muon tracker
Authors: Yang Guangliang , Schoetker Josh , Poulson Dan , Guardincerri Elena , Durham J. M. , Vogel Sven , Hoerner Shaun , Aberle Derek , Sun Ke-Xun , Morris C. L. , Kaiser Ralf , Osborne Andrew
Published: August 2023

Cosmic ray muons are massive, charged particles created from high energy cosmic rays colliding with atomic nuclei in Earth’s atmosphere. Because of their high momenta and weak interaction, these muons can penetrate through large thicknesses of dense material before being absorbed, making them ideal for nondestructive imaging of objects composed of high-Z elements. A Giant Muon Tracker with two horizontal 8 × 6 ft.2 and two vertical 6 × 6 ft.2 modules of drift tubes was used to measure muon tracks passing through samples placed inside the detector volume. The experimental results were used to validate a Monte Carlo simulation of the Giant Muon Tracker. The imaging results of simulated samples were reconstructed and compared with those from the experiment, which showed excellent agreement.
DeePMD-kit v2: A software package for deep potential models
Authors: Zeng Jinzhe , Zhang Duo , Lu Denghui , Mo Pinghui , Li Zeyu , Chen Yixiao , Rynik Marián , Huang Li’ang , Li Ziyao , Shi Shaochen , Wang Yingze , Ye Haotian , Tuo Ping , Yang Jiabin , Ding Ye , Li Yifan , Tisi Davide , Zeng Qiyu , Bao Han , Xia Yu , Huang Jiameng , Muraoka Koki , Wang Yibo , Chang Junhan , Yuan Fengbo , Bore Sigbjørn Løland , Cai Chun , Lin Yinnian , Wang Bo , Xu Jiayan , Zhu Jia-Xin , Luo Chenxing , Zhang Yuzhi , Goodall Rhys E. A. , Liang Wenshuo , Singh Anurag Kumar , Yao Sikai , Zhang Jingchao , Wentzcovitch Renata , Han Jiequn , Liu Jie , Jia Weile , York Darrin M. , E Weinan , Car Roberto , Zhang Linfeng , Wang Han
Published: August 2023

DeePMD-kit is a powerful open-source software package that facilitates molecular dynamics simulations using machine learning potentials known as Deep Potential (DP) models. This package, which was released in 2017, has been widely used in the fields of physics, chemistry, biology, and material science for studying atomistic systems. The current version of DeePMD-kit offers numerous advanced features, such as DeepPot-SE, attention-based and hybrid descriptors, the ability to fit tensile properties, type embedding, model deviation, DP-range correction, DP long range, graphics processing unit support for customized operators, model compression, non-von Neumann molecular dynamics, and improved usability, including documentation, compiled binary packages, graphical user interfaces, and application programming interfaces. This article presents an overview of the current major version of the DeePMD-kit package, highlighting its features and technical details. Additionally, this article presents a comprehensive procedure for conducting molecular dynamics as a representative application, benchmarks the accuracy and efficiency of different models, and discusses ongoing developments.
Application of a hyperspectral camera for in situ plasma–material interaction studies at the linear plasma device PSI-2
Authors: Li Changjun , Brezinsek Sebastijan , Ertmer Stephan , Kreter Arkadi , Reinhart Michael , Ding Rui , Chen Junling
Published: August 2023

A hyperspectral camera (HSC-type Specim IQ) has been applied at the linear plasma device PSI-2 under steady-state conditions. The camera has the capacity of hyperspectral imaging (HSI) with the dimension of a data array 512 × 512 × 204 (x, y, λ) covering the spectral span from 400 to 1000 nm with moderate average spectral resolution (FWHM ∼7 nm). After radiometric calibration and background/continuum emission subtraction, two main applications of the camera, (i) plasma diagnostics in helium (He) plasmas and (ii) plasma–material interaction studies with tungsten (W) targets in neon (Ne) plasmas, have been carried out. The measurements were complemented by a movable Langmuir double probe system (LP) measuring electron temperature (Te) and electron density (ne) in radial direction r and a fiber-coupled cross-dispersion spectrometer with high spectral resolution (Spectrelle) recording neutral He, W, and Ne emission lines over the full plasma column. (i) Two-dimensional (2D) imaging of Te and ne radial profiles in axial direction z of the He plasma column were for the first time obtained by the regression analysis of Te and ne (from LP) and six He I line ratios (from HSC). The spatially resolved plasma parameters covered in these studies range between Te ∼ 0.8–13.4 eV and ne ∼ 0.2 × 1018–3.9 × 1018 m−3 and permit a reconstruction of the plasma conditions in PSI-2 in 2D without LP perturbation. (ii) W sputtering was studied in situ in Ne plasmas exposing W target samples (negatively biased at 100 V) under perpendicular Ne plasma impact. Simultaneously, the 2D distributions of W (W I line at 429.5 nm) in front of the target and the 2D Ne plasma distribution (Ne I line at 703.2 nm) were recorded with complete spectral separation as confirmed by the Spectrelle spectrometer. This permits the simultaneous measurement of the neutral W penetration and its angular distribution induced in the sputtering process and of the impinging plasma distribution. The HSI technique offers, despite a few technical drawbacks, such as the moderate spectral resolution and poor time resolution, a new possibility to distinguish multiple emission lines from plasma and impurities and complements the portfolio of existing Optical Emission Spectroscopy techniques, providing a good compromise regarding spectral, spatial, and temporal resolution.
Electric- and magnetic-dipole surface lattice resonances in microwave regime
Authors: Zhang Shi-qian , Zhang Yong , Yin Xiao-gang , Kong Ling-bao , Huang Cheng-ping
Published: August 2023

At optical frequencies, the collective excitation of the periodic array of metallic meta-molecules can support surface lattice resonances (SLRs) due to the coupling of localized surface-plasmon (LSP) resonances to Rayleigh anomaly diffraction. However, the LSP effect in metal blocks becomes negligible in the microwave region. Thus, how the SLRs behave in the microwave regime is very interesting. In this paper, a microwave metasurface consisting of periodic metallic cubes on an ultrathin dielectric substrate is investigated. Two high-Q transmission dips are found, which can be attributed, respectively, to electric-dipole SLRs (ED-SLRs) and magnetic-dipole SLRs (MD-SLRs), because of the non-resonant Rayleigh-like scattering of single cubes and diffraction coupling of the periodic array. The frequencies of both ED- and MD-SLRs are sensitive to the refractive index of the substrate, suggesting that the proposed metasurface may be used to measure the refractive index in the microwave range.
Performance comparison of refrigerators integrated with superhydrophobic and superhydrophilic freezer evaporators
Authors: Ghaddar Dalia , Boyina Kalyan , Chettiar Kaushik , Hoque Muhammad Jahidul , Baker Matthew , Bhalerao Pushkar , Reagen Scot , Miljkovic Nenad
Published: August 2023

Micro and nanostructures can delay frost and ice buildup, improve defrosting efficiency, and reduce water retention. Here, we examine the impact of nanostructures on aluminum evaporators during frosting and defrosting inside of a 20.5 ft3 commercial food refrigerator. We use scalable manufacturing methods to generate structures on the external surfaces of the heat exchangers using bohemitization and chemical vapor deposition, rendering them superhydrophilic or superhydrophobic. Our results demonstrate a 93% reduction in water retention for the superhydrophobic heat exchanger compared to its uncoated and superhydrophilic counterparts. We conduct frosting and defrosting visualization experiments in the refrigerator to show frost pattern growth and droplet distributions on the heat exchangers. Frost was fluffier and less dense on the superhydrophobic heat exchanger compared to its counterparts which resulted in sparse droplets that are easily removed during defrosting. Furthermore, we show that the superhydrophobic heat exchanger can decrease energy consumption by 13.6% during defrosting when compared to its uncoated and superhydrophilic counterparts. We also comment on the durability of the applied coating on the heat exchangers. This study provides guidelines for the broader integration of micro and nanostructured surfaces with refrigeration and cooling appliances to create energy savings.
Design and evaluation of a magnetically coupled piezoelectric energy harvester with parallel connection
Authors: Zhang Yaxun , Wang Heran , Wang Liang
Published: August 2023

This work proposed a magnetically coupled piezoelectric energy harvester with parallel connections. The rectangular piezoelectric patch in the upper part of the device generates regular vibrations due to the nonlinear forces caused by magnetic coupling. The lower rectangular piezoelectric patch is deformed by contact collision excitation. The parallel connection effectively connects the two sets of piezoelectric patches together and fully exploits the performance of the piezoelectric energy harvester. The intrinsic frequency of the rectangular piezoelectric patch was simulated and verified experimentally. The rectangular piezoelectric patch generates a large vibration amplitude in high-speed operation due to its elasticity property. From the experimental results, it can be seen that the piezoelectric energy harvester can work well in different frequency bands. The parallel piezoelectric energy harvester with a three-contact rotor has a peak-to-peak voltage of 252 V at a speed of 120 r/min and 200 V at a speed of 240 r/min. The maximum voltage achieved by the piezoelectric energy harvester in parallel is 266 V at a speed of 180 r/min with a resistance of 1000 kΩ. The maximum voltage reached by a series-connected piezoelectric energy harvester is 256 V at a speed of 180 r/min and a resistance of 100 kΩ. The peak-to-peak power of the piezoelectric energy harvester connected in parallel is 0.313 W under a resistance of 100 kΩ and a speed of 180 r/min. Besides, the developed piezoelectric energy harvester can light up to 60 light-emitting diodes. Accordingly, the energy can be effectively harvested by the piezoelectric energy harvester and then supplied to the microelectronic device.
Marangoni instability of an evaporating binary mixture droplet
Authors: Li Chunxi , Zhang Ningkang , Wang Xiaoyu , Ye Xuemin
Published: August 2023

Evaporation of a binary mixture droplet (BMD) is a common natural phenomenon and widely applied in many industrial fields. For the case of a sessile BMD being the only contact-line pinning throughout an entire evaporation, a theoretical model describing the evaporating dynamics is established when considering the comprehensive effect of evaporative cooling, the thermal Marangoni effect, the solutal Marangoni effect, the convection effect, and the Stefan flow. The dynamics of a binary ethanol–water droplet on a heated substrate is simulated using a cylindrical coordinate system. The reasons for Marangoni instability-driven flow (MIF) are discussed, and the influence of initial ethanol concentration and substrate heating temperature are examined. An evaporating BMD first forms a MIF at the contact line and quickly affects the whole droplet. Under the influence of the Marangoni instability, the BMD presents a complex internal flow structure with multiple-vortex and nonlinear temperature and ethanol concentration distributions. The positive feedback induced by vortices and the nonlinear distribution of concentration and temperature promotes the development of a MIF. At low initial ethanol concentrations, the MIF loses its driving force and turns into a stable counterclockwise single-vortex flow as ethanol evaporates completely. However, at high initial ethanol concentrations, the MIF exists in the entire evaporation. Increasing ethanol concentration and substrate heating temperature can delay the appearance of the MIF; ethanol concentration affects the MIF duration time, and heating temperature alters the MIF intensity. To enhance flow intensity and mass transfer of BMDs, the temperature difference should first be increased, followed by increased ethanol concentration.
Design and evaluation of a stick-slip piezoelectric actuator with flexure hinge mechanism inspired by the earthworm
Authors: Wang Heran , Su Donghao , Wang Liang
Published: August 2023

In this work, a new bionic piezoelectric actuator inspired by the earthworm is proposed, fabricated, and tested. The operating principle of the actuator imitates the crawling motion of the earthworm. The piezoelectric stack is embedded in the stator with a flexure hinge mechanism. One side of the stator is inspired by the earthworm body. Then the elongation of the piezoelectric stack is transmitted to the driving tip to produce oblique displacement under such a stator. The vertical and horizontal components are used to press and drive the slider, respectively. The principle of the proposed actuator is described in detail. The static deformation is investigated by the FEM method. A dynamic model of the actuator is developed to further reveal the motion characteristics of the slider via theoretical analysis. Finally, the output characteristics of the proposed BPA are tested. The experimental results show that the actuator achieves a maximum output speed of 12.72 mm/s at a voltage of 100 V and a frequency of 710 Hz. The maximum output force is 3 N under a locking force of 2 N. Besides, the displacement resolution is tested at 87 nm at a frequency of 710 Hz, which indicates that the developed actuator can be applied in the field of precision actuation.
Generating high-efficiency swimming kinematics using hydrodynamic eigenmode decomposition
Authors: Smyth A. S. M. , Young A. M. , Di Mare L.
Published: August 2023

This paper explores the use of hydrodynamic eigenmode decomposition as a means of generating optimal swimming kinematics of slender three-dimensional bodies. The eigenvectors of the unsteady hydrodynamic system are used as basis functions for the response to external forcing, such as perturbations generated by the deformation of the body. Exploiting the orthogonality of the modes, we show that swimming according to a single appropriately selected hydrodynamic eigenmode results in high-efficiency swimming. To demonstrate this result, we use an inviscid three-dimensional vortex lattice model to investigate the hydrodynamic eigenmodes of a selection of geometries. We find that for all of the body geometries tested, hydrodynamic efficiency far exceeding that of pure heaving or pitching can be achieved. All eigenmodes tested produce high-efficiency motion, as long as the beat frequency is higher than the mode's “cut-in” frequency for thrust generation. The eigenmodes show qualitative similarity to swimming patterns observed in nature and also correspond well to the existing classifications of undulatory and oscillatory swimming. This study demonstrates that the hydrodynamic eigenmode analysis can generate high-efficiency swimming kinematics based only on information about the body and wake geometry, and as such, this method has significant potential for further development and application to autonomous underwater vehicle design.
Quantum dynamics of the internal motion of biphenyl-based molecular junctions
Authors: Leal-Sánchez Edith , Hernández-Trujillo Jesús
Published: August 2023

Single molecule junctions based on selected 4,4′-biphenyldithiol and 4,4′-dicyanobiphenyl derivatives bonded to gold electrodes are analyzed from a dynamical point of view. A fully quantum mechanical description of the internal rotation of the biphenyl moiety is carried out in terms of the nuclear wavepacket dynamics obtained by the solution of the time-dependent Schrödinger equation expressed in terms of the torsion angle between the phenyl rings. The required potential energy surfaces are computed using ab initio electronic structure methods. The nature and positions of the substituents on the phenyl rings determine the features of the potential energy surfaces. The effect of the initial conditions on the time propagation of the nuclear wavepackets and, as a consequence, on the evolution of the conformational distribution is also analyzed. In addition, the conductances at zero bias for the nanojunctions were computed for different conformations of the biphenyl fragments. Weighted by the wavepacket amplitudes, non-stationary conductance expectation values, and time-averaged torsion angles and conductances for the entire simulation are obtained. The consequences of using the time-averaged values to perform a linear regression between the conductance and the square of the cosine of the dihedral angle between the phenyl rings are analyzed and compared to the usual static approach based only on the information for equilibrium geometries. The study of the time dependent conformational variations of the biphenyl moieties in the nanojunctions allows for a better understanding of the quantum chemical phenomena that affect their transport properties.
Prediction of wind shear layer for dynamic soaring by using proper orthogonal decomposition and long short term memory network
Authors: Wang Danxiang , Xie Fangfang , Ji Tingwei , Zhang Xinshuai , Lu Yufeng , Zheng Yao
Published: August 2023

The wind shear layer is a naturally formed airflow that enables the albatross to soar for six days at almost no cost. The modeling and prediction of the wind shear layer can be very helpful for a long-endurance flight (dynamic soaring), but the existing studies usually ignore the turbulence structures of wind shear layers. In this paper, the wind shear layer on the leeward side of the ridge is simulated by a large eddy simulation (LES) method to analyze the turbulence structures. In the numerical simulation, the three-dimensional (3D) elevation data of the mountain is used as the topography at the bottom and the synthesized turbulent velocity is used as the inlet boundary. Because of the huge computational cost of 3D simulations, a data-driven predicting framework is also established to reduce the cost and maintain the prediction accuracy, which includes an offline training stage and an online forecasting stage. In the offline stage, the proper orthogonal decomposition (POD) is used to extract features from the LES data of wind velocity fields and the obtained POD coefficients are used to train the long short term memory (LSTM) networks. In the online stage, the future wind fields are predicted by the trained LSTM networks in the noisy and real-time environment. In conclusion, this paper analyzed the physical characteristics of the wind shear layer on the leeward side of the ridge and provided the accurate prediction for these characteristics.
Dispersion of expectorated cough droplets with seasonal influenza in an office
Authors: Norvihoho Leslie K. , Li Hang , Zhou Zhi-Fu , Yin Jing , Chen Shu-Yan , Zhu Dong-Qing , Chen Bin
Published: August 2023

We do not fully grasp viral droplet transmission processes in ventilated interior environments. The core focus of our research is to investigate the effectiveness of the protected occupied zone ventilation (POV) through computational fluid dynamics models in a simplified office setting. The large-eddy simulation technique with the Eulerian–Lagrangian model was implemented to address complicated indoor processes such as turbulence, flow–aerosol interaction, and ventilation impact. We computationally investigated the effects of desk partitions and the POV on cough droplets in an office. The ventilation approach was tested using two distinct exhaust layouts and four different ventilation rates (1.0, 1.2, 1.5, and 1.8 m/s). A comparative analysis of the ventilation flow fields, topologies, and particle directions has been studied. The findings indicate that the plane jet's ventilation rates influence the protected occupied zone ventilation performance. The ventilation rates distributed the virus droplets around the room, but compared to the up-exhaust cases, the down-exhaust cases appeared to have better shielded the healthy person. This pattern could indicate that the placement of the exhaust outlet in ventilation systems significantly influences indoor aerosol dispersion. The results also show that substantial flow streams may carry tiny particles (≤70 μm) throughout their path. Large particles (≥100 μm) could not go far in cough gas clouds. Most viral particles deposit on solid surfaces in various work sites per specific ventilation rates. Office workers need to be very cautious around these hazardous areas.
Channelling flows in the Hunter Valley
Authors: Webb Christopher , Park Jiwon
Published: August 2023

The Hunter Valley is well known for the strong westerly winds in winter and elevated fire danger arising from hot and dry north-westerly winds in summer. These hazards are closely related to the valley channelling in the region, and the connection between the two has been an interest to weather forecasters, emergency service personnel, and the aviation industry. In this paper, the climatology of valley winds is constructed to identify the dominant types of channelling in the Hunter Valley and their preferred directions using the 10-year data of Automatic Weather Station observations, upper air sounding and ERA5 reanalysis data between July 2010 and June 2020. Particular attention is given to the conceptual model of pressure-driven channelling of westerlies in winter and its mechanics, as the climatology shows that it is the main cause of wind-warning conditions in the Hunter.
The structure of
Plasmodium falciparum
multidrug resistance protein 1 reveals an N-terminal regulatory domain
Authors: Si Kaixue , He Xishuo , Chen Liping , Zhang Anqi , Guo Changyou , Li Minghui
Published: August 2023

Plasmodium falciparum
multidrug resistance protein 1 (PfMDR1), an adenosine triphosphate (ATP)-binding cassette (ABC) transporter on the digestive vacuole (DV) membrane of the parasite, is associated with the resistance to antimalarial drugs. To understand the mechanisms of PfMDR1, we determined the cryo-electron microscopy structures of this transporter in different states. The transporter in the apo state shows an inward-facing conformation with a large cavity opening to the cytoplasm. Upon ATP binding and dimerization of the nucleotide-binding domains (NBDs), PfMDR1 displays an outward-facing conformation with a cavity toward the DV lumen. Drug resistance–associated mutations were investigated in both structures for their effects, and Y184F was identified as an allosteric activity-enhancing mutation. The amphiphilic substrate-binding site of PfMDR1 was revealed by the complex structure with the antimalarial drug mefloquine and confirmed by mutagenesis studies. Remarkably, a helical structure was found to hinder NBD dimerization and inhibit PfMDR1 activity. The location of this regulatory domain in the N terminus is different from the well-studied R domain in the internal linker region of other ABC transporter family members. The lack of the phosphorylation site of this domain also suggests a different regulation mechanism.
Emergence of tunable periodic density correlations in a Floquet–Bloch system
Authors: Dupont Nathan , Gabardos Lucas , Arrouas Floriane , Chatelain Gabriel , Arnal Maxime , Billy Juliette , Schlagheck Peter , Peaudecerf Bruno , Guéry-Odelin David
Published: August 2023

In quantum gases, two-body interactions are responsible for a variety of instabilities that depend on the characteristics of both trapping and interactions. These instabilities can lead to the appearance of new structures or patterns. We report on the Floquet engineering of such a parametric instability, on a Bose–Einstein condensate held in a time-modulated optical lattice. The modulation triggers a destabilization of the condensate into a state exhibiting a density modulation with a new spatial periodicity. This new crystal-like order, which shares characteristic correlation properties with a supersolid, directly depends on the modulation parameters: The interplay between the Floquet spectrum and interactions generates narrow and adjustable instability regions, leading to the growth, from quantum or thermal fluctuations, of modes with a density modulation noncommensurate with the lattice spacing. This study demonstrates the production of metastable exotic states of matter through Floquet engineering and paves the way for further studies of dissipation in the resulting phase and of similar phenomena in other geometries.
“I don’t know if we should have that discussion now”
Authors: Hallgren Lars , Bergeå Hanna , Montgomerie Emily , Westberg Lotten
Published: August 2023

Collaborative governance within natural resource management relies on dialogical forums where people can negotiate
complex issues through conversations. In this paper, we investigate situations where procedural frames around these discussions
are negotiated in the conversations between its participants in a corpus from five different natural resource management contexts.
We present how frame discussions are initiated, how actors express that actions are not aligned with the frames, and finally, how
these openings of discourse about the frames are interactively managed, maintained, and closed. We argue norms of inclusiveness,
consensus, and performance shape the interaction and hamper the joint investigation of the frames, and undermine the entire
justification of the collaborative processes and the core quality of dialogical conversations.
Debate or dialogue?
Authors: Žákovská Iveta
Published: August 2023

The present paper deals with an example of a TV broadcast discussion program, the Czech programMáte slovo, in which a dialogue fails. It presents a closer analysis of one representative episode of the program, which, despite being officially presented as offering space for discussion and a chance for ordinary citizens to talk to public personalities and politicians, takes the form of confrontainment, whose goal is to escalate debate. The paper reveals what practices by the discussants and the moderator contribute to the failure of a successful dialogue and discusses the role of broadcast programs of this kind in the contemporary communication sphere.
Innovation management in agricultural production in Kazakhstan
Authors: Taishykov Zhandos , Tolysbayev Baurzhan , Kuantkan Bibolat , Koichubayev Alexandr , Baigabulova Kulyash
Published: August 2023

In modern conditions in agriculture, the main priorities in development are scientific and technological progress and innovation, which, based on the achievements of science and technology, allow the renewal of production, and their implementation and management are the relevance of the theme of the study. The purpose of the work is to identify trends in theoretical and methodological foundations and opportunities for enhancing scientific and innovation processes, as well as priorities of prospective development in innovation management in agricultural production in Kazakhstan. The subject of the research is innovation activity in agriculture. A set of special and general scientific methods was used in the research process. The theoretical basis of the research conducted was provided by the endpoints, and the main conclusions and basic recommendations are presented and substantiated by the research of scientists, also, the works of researchers in the field of innovative development and management in the research of international economic relations problems. The results of the study established that the priority direction in the agrarian policy of Kazakhstan in the field of innovation is the development and introduction of modern knowledge and technologies in the sector of the economy, an increase of financing of agrarian science, production of new crop varieties, development of new animal breeds, improvement of quality and efficiency of veterinary care, a system of field irrigation and soil treatment, reduction of crop production costs, genomic breeding.
Botswana’s New Tourism Policy of 2021 and Mantras of Citizen Empowerment and Product Diversification: A Case of Going Backward to Move Forward
Authors: Lenao Monkgogi
Published: August 2023

Botswana’s first tourism policy was published in 1990 as the first true attempt at formalizing tourism activities in the country. The policy advocated for a high-cost, low-volume (HC, LV) marketing approach for general tourism practice in Botswana. This policy position has received reviews from various stakeholders, some of whom decry its exclusionary consequences for both citizen entrepreneurs and travellers. In 2021, the Revised Tourism Policy was released following a lengthy review process dating back to 2008. The newly revised policy prescribes a high volume/mixed price strategy in recognition of the constraints embedded in the founding policy’s approach. To this end, the revised policy promises a more citizen-friendly tourism environment where local participation would be improved and benefits spread more equitably to citizens. While explicitly making pronouncements on how an increase in domestic travel shall be facilitated, as well as calling for local participation at the entrepreneurial level, two things remain unchanged. At most, the revised policy retains its predecessor’s government-centred approach as well as wildlife and wilderness-centred thinking. The government-centred dispensation is aptly captured in the policy as a government-led, private-sector-driven, and community-based tourism development approach. The current case addresses the challenges of a government-centred policy in the wake of citizen empowerment and participation in community-based tourism.

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Scaling Up Sustainability: The Case of Big Wheel Burger
Authors: L.M. Coughlan , R. Dodds
Published: August 2023

After waking up from a 5-day coma after a sports injury, Calen McNeil did not want to waste his second chance at life and knew his purpose was to do something good and valuable. Big Wheel Burger has been adding locations at a steady pace since opening its doors in 2011 and was also Canada’s first carbon-neutral fast-food restaurant. With five locations currently open and another due to open later in 2023, Calen knew that his business model was a good one, but he also knew profits were not the only thing in question. Ever since the COVID-19 pandemic, he realized he wanted to play a bigger role in helping his community. The question was, how could he change his business model to have an even greater positive impact?

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Mechanistic understanding of KCNQ1 activating polyunsaturated fatty acid analogs
Authors: Jowais Jessica J. , Yazdi Samira , Golluscio Alessia , Olivier-Meo Vanessa , Liin Sara I. , Larsson H. Peter
Published: August 2023

The KCNQ1 channel is important for the repolarization phase of the cardiac action potential. Loss of function mutations in KCNQ1 can cause long QT syndrome (LQTS), which can lead to cardiac arrythmia and even sudden cardiac death. We have previously shown that polyunsaturated fatty acids (PUFAs) and PUFA analogs can activate the cardiac KCNQ1 channel, making them potential therapeutics for the treatment of LQTS. PUFAs bind to KCNQ1 at two different binding sites: one at the voltage sensor (Site I) and one at the pore (Site II). PUFA interaction at Site I shifts the voltage dependence of the channel to the left, while interaction at Site II increases maximal conductance. The PUFA analogs, linoleic–glycine and linoleic–tyrosine, are more effective than linoleic acid at Site I, but less effective at Site II. Using both simulations and experiments, we find that the larger head groups of linoleic–glycine and linoleic–tyrosine interact with more residues than the smaller linoleic acid at Site I. We propose that this will stabilize the negatively charged PUFA head group in a position to better interact electrostatically with the positively charges in the voltage sensor. In contrast, the larger head groups of linoleic–glycine and linoleic–tyrosine compared with linoleic acid prevent a close fit of these PUFA analogs in Site II, which is more confined. In addition, we identify several KCNQ1 residues as critical PUFA-analog binding residues, thereby providing molecular models of specific interactions between PUFA analogs and KCNQ1. These interactions will aid in future drug development based on PUFA–KCNQ1 channel interactions.
Ultrasonic guided wave imaging of pipelines based on physics embedded inversion neural network
Authors: Lv Lingling , Chen Shili , Tong Junkai , Chen Xin , Zeng Zhoumo , Liu Yang
Published: August 2023

Pipeline corrosion quantification plays a vital role in guaranteeing the safety of critical industrial structures and thus significant work has been carried out to address such an issue. Although quantitative imaging is crucial for non-destructive testing, research in guided wave pipeline testing has primarily centered on qualitative approaches. Here, we propose a deep neural network built upon physical model to reconstruct pipe wall thickness from ultrasonic guided wave (UGW) signals. The workflow of reconstruction contains three layers, where each layer consists of a fixed forward network and a residual inversion network. The forward model is represented by an agent convolutional neural network which would be embedded into the entire inversion network. The residuals between data from the forward model and real signals are then mapped into velocity profile differences through sub-inversion network. Numerical experiments were conducted to verify the inversion performance of the deep neural network using thickness maps obtained from guided wave frequency domain information. Results show that inversion images are capable to reveal the positions, shapes, and depths of corrosion with high resolution and precision, yielding an average inversion of 87.37% in the test set. In addition, by utilizing the periodicity of the pipeline, the inversion accuracy of eight pairs of transducers were improved from 67.7% to 89.43% with high-order helical guided wave. Compared with traditional high-precision inversion methods such as full waveform inversion, the proposed method achieved approximately 300 times faster inversion speed at the cost of some accuracy. The research demonstrates that real-time quantitative imaging of defects on pipes can be achieved accurately by physics embedded network. Furthermore, an experimental verification of the method was carried out through UGW pipeline testing, demonstrating its feasibility. The mean squared error of wall thickness reconstruction was 0.0070, achieving a high level of precision.
A novel material identification method for different thermal conductivities materials based on the micro thermoelectric generator
Authors: Chen Nanxi , Liu Changxin , Shan Baichuan , Chen Runhe , Xing Guangyi , Shao Tong
Published: August 2023

An artificial intelligence (AI) technical system is the foundation of the internet of things. While in the technical system, the material identification technology is the key point. Material identification technology can be applied to AI robots and smart skin. However, most of the traditional material identification technologies have limitations such as high cost and complicated operation, while the low-cost ones have the problem of low accuracy. To accurately, efficiently, and simply identify objects is a bottleneck that researchers urgently need to overcome. Based on the thermoelectric effect, a material identification theory is proposed and a prototype is fabricated in this paper. A series of experiments are carried out to test the performance of the prototype. According to the results, the prototype can precisely identify metal materials and nonmetal materials less than 3 s. There are many merits of the prototype, such as high identification accuracy, low cost, and low maintenance difficulty. Besides, considering complex surface of materials may decrease the identification accuracy, this paper proposes a kind of flexible thermal conductive material to improve identification accuracy. It is verified that the identification accuracy is improved with the flexible thermal conductive material.
Electrical performance enhancement of a triboelectric nanogenerator based on epoxy resin/BaTiO3 by Al nanopowder addition for low power electronic devices
Authors: Amorntep Narong , Namvong Ariya , Wongsinlatam Wullapa , Remsungnen Tawun , Siritaratiwat Apirat , Srichan Chavis , Sriphan Saichon , Pakawanit Phakkhananan , Ariyarit Atthaporn , Supasai Wisut , Jutong Nuttachai , Narkglom Sorawit , Surawanitkun Chayada
Published: August 2023

Triboelectric nanogenerators (TENGs) are crucial for applications such as smart sensors and bio-electronics. In the current work, we aimed for improved performance of TENGs with incorporation of BaTiO3 powder, which is known for its strong ferroelectric properties, combining it with epoxy resin to improve the flexibility of our devices. We observed that our TENGs can operate for over 24 000 cycles with no degradation of function. Additionally, we improved the electrical performance of the TENGs by incorporating various aluminum concentrations that change the electronic properties in the form of mixed epoxy resin, BaTiO3, and Al nanopowders. To identify the optimum conditions for the best performance, we analyzed the electrical characteristics and material properties by employing scanning electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffractometry characterization techniques. Our findings suggest that this innovative combination of materials and optimization techniques can significantly improve the performance of TENGs, making them ideal for practical applications in various fields, such as low-power electronics, environmental monitoring and healthcare. Moreover, these enhanced TENGs can serve as sustainable and dependable energy sources for various applications.
The development of folate-functionalised palladium nanoparticles for folate receptor targeting in breast cancer cells
Authors: Gandidzanwa Sendibitiyosi , Beukes Natasha , Joseph Sinelizwi V , Janse Van Vuuren Arno , Mashazi Philani , Britton Jonathan , Kilian Gareth , Roux Saartjie , Nyokong Tebello , Lee Michael E , Frost Carminita L , Tshentu Zenixole R
Published: August 2023

Folate receptor-targeted therapy has excellent prospects for the treatment of breast cancer. A non-toxic concentration of folate-conjugated palladium-based nanoparticles was used to target the overexpressed folate receptor on breast cancer cells. The folate-conjugated nanoparticles were tailored to accumulate selectively in cancer cells relative to normal cells via the folate receptor. The MDA-MB-231, MDA-MB-468, MCF-7 breast cancer cell lines, and MCF-10A normal cell lines were used in the study. Qualitative and quantitative analysis of nanoparticle cellular uptake and accumulation was conducted using transmission electron microscopy and inductively coupled plasma-optical emission spectroscopy. The findings proved that folate-conjugated palladium nanoparticles successfully and preferentially accumulated in breast cancer cells. We conclude that folate-conjugated palladium nanoparticles can be potentially used to target breast cancer cells for radiopharmaceutical applications.
Data-driven reconstruction of stochastic dynamical equations based on statistical moments
Authors: Nikakhtar Farnik , Parkavousi Laya , Sahimi Muhammad , Reza Rahimi Tabar M , Feudel Ulrike , Lehnertz Klaus
Published: August 2023

Stochastic processes are encountered in many contexts, ranging from generation sizes of bacterial colonies and service times in a queueing system to displacements of Brownian particles and frequency fluctuations in an electrical power grid. If such processes are Markov, then their probability distribution is governed by the Kramers–Moyal (KM) equation, a partial differential equation that involves an infinite number of coefficients, which depend on the state variable. The KM coefficients must be evaluated based on measured time series for a data-driven reconstruction of the governing equations for the stochastic dynamics. We present an accurate method of computing the KM coefficients, which relies on computing the coefficients’ conditional moments based on the statistical moments of the time series. The method’s advantages over state-of-the-art approaches are demonstrated by investigating prototypical one-dimensional stochastic processes with well-known properties.
Parity violating gravitational waves at the end of inflation
Authors: Bastero-Gil Mar , Torres Manso António
Published: August 2023

Inflaton-vector interactions of the typeϕFF̃have provided interesting phenomenology to tackle some of current problems in cosmology, namely the vectors could constitute the dark matter component. It could also lead to possible signatures imprinted in a gravitational wave spectrum. Through this coupling, a rolling inflaton induces an exponential production of the transverse polarizations of the vector field, having a maximum at the end of inflation when the inflaton field velocity is at its maximum. These gauge particles, already parity asymmetric, will source the tensor components of the metric perturbations, leading to the production of parity violating gravitational waves. In this work we examine the vector particle production in the weak coupling regime, integrating the gauge mode amplitudes spectrum during the entirety of its production and amplification epochs, until the onset of radiation domination. Finally, we calculate the gravitational wave spectrum combining the vector mode analytical solution, the WKB expansion, valid only during the amplification until horizon crossing, and the numerical solution obtained at the beginning of radiation domination when the modes cease to grow.
Rubidium-induced phase transitions among metallic, band-insulating, Mott-insulating phases in 1T -TaS2
Authors: Wang 王 Zhengguo 政国 , Yao 姚 Weiliang 伟良 , Wang 王 Yudi 宇迪 , Xin 信 Ziming 子鸣 , Han 韩 Tingting 婷婷 , Chen 陈 Lei 磊 , Ou 欧 Yi 仪 , Zhu 朱 Yu 玉 , Cai 蔡 Cong 淙 , Li 李 Yuan 源 , Zhang 张 Yan 焱
Published: August 2023

Realizing phase transitions via non-thermal sample manipulations is important not only for applications, but also for uncovering the underlying physics. Here, we report on the discovery of two distinct metal–insulator transitions in 1T-TaS2 via angle-resolved photoemission spectroscopy and in-situ rubidium deposition. At 205 K, the rubidium deposition drives a normal metal–insulator transition via filling electrons into the conduction band. While at 225 K, however, the rubidium deposition drives a bandwidth-controlled Mott transition as characterized by a rapid collapsing of Mott gap and a loss of spectral weight of the lower Hubbard band. Our result, from a doping-controlled perspective, succeeds in distinguishing the metallic, band-insulating, and Mott-insulating phases of 1T-TaS2, manifesting a delicate balance among the electron-itineracy, interlayer-coupling and Coulomb repulsion. We also establish an effective method to tune the balance between these interactions, which is useful in seeking exotic electronic phases and designing functional phase-changing devices.