bluuebunny/crossref_metadata_2025 huggingface dataset:
Technology for preparing fruit and vegetable desserts for baby food
Authors: Blinkov Alexey , Sutorma Oksana , Efremova Elena , Randelin Dmitry
Published: December 2023

To expand the range of desserts for school meals, hypoallergenic fruits and vegetables were used in our study. Zucchini, green apple and white currant as the main ingredients of sorbet were selected taking into account the recommendations of a non-specific hypoallergenic diet. Purpose of the work: to study the organoleptic characteristics of a new fruit and vegetable dessert. Objectives: to consider the organoleptic characteristics of products. The study of organoleptic indicators was carried out in accordance with GOST 31986-2012. Test batches of the dessert were carried out at the Volgograd State Agrarian University at the Department of Processing and Food Production Technologies. In terms of organoleptic indicators, the new product met all technical requirements. The appearance of sorbet, a single-layer dessert in the form of a ball without glaze, decorated with mint greens. The consistency is dense. The taste is clean, characteristic of apple and currant, without any foreign tastes or odors. The color is light green, uniform throughout the mass. The product sample meets the requirements of GOST R 55624-2013 “Whipped frozen fruit, vegetable and fruit-vegetable desserts. Technical conditions”.
The use of a microcontroller as part of a device for measuring humidity using the thermogravimetric method
Authors: Lebedinskaya Sofia , Leshchenko Aleksei , Evdokimov Aleksei
Published: December 2023

The use of a microcontroller as part of a device for measuring humidity using the thermogravimetric method is considered. The main nodes of the device have been designed, in which the microcontroller receives and processes information from them, and also controls these nodes. They use various microcontroller capabilities, including several data transfer interfaces: I2C, SPI, etc. A built-in analog-to-digital converter is used. The power control unit allows you to flexibly set the required heater power in the device. A unit has been created to control the mass of a material sample in the drying chamber of the device, which provides an accurate measurement of the mass of the substance. The temperature control unit allows the microcontroller to evaluate the material drying parameters and select the operating mode of the power regulator. The performance of the designed units was tested. It is noted that they can be used in a device for measuring humidity using the thermogravimetric method under the control of a single microcontroller.
Study of floods on the rivers of the Kaliningrad region at the beginning of 2020 in the absence of snow cover and ice
Authors: Akhmedova Natalya , Naumov Vladimir
Published: December 2023

To develop measures for engineering protection of territories from flooding, it is necessary to identify spatiotemporal patterns in the formation of floods, since they are the cause of devastating floods in recent years. The paper presents the results of an analysis of flood phenomena on the rivers of the Kaliningrad region at the beginning of 2020. An array of observational data on daily water flows in rivers was processed, and the main components of the water balance of river basins were assessed by month (amount of precipitation, evaporation layer, monthly river flow layer, change in basin moisture reserves). It was found that the greatest amount of runoff was in February, while the highest amount of precipitation was in June; the highest runoff coefficient was in March and February (0.41), and in June it was only 0.03. Presumably, the main reasons for such phenomena are the distribution of the evaporation layer within the year and a decrease in the permeability of the upper soil layer for precipitation at low temperatures.
Optimal volume of flow tanks for rainwater management
Authors: Gudkov Alexandr
Published: December 2023

The purpose of the article is to specify and supplement the methodology of engineering calculation of rain runoff control at the treatment plant, given the current regulatory and methodological framework. Two flow management schemes, including an intermediate tank, a pumping station, and a separation chamber, have been analyzed by mathematical modeling. Changes in the calculation formula for determining the required volume for the tank connection scheme when emptying the tank by gravity are proposed. There is a significant difference in the calculation results according to the proposed and current regulatory methodologies.
Plants of the Siberian flora exposition of the N.V. Tsitsin Main Botanical Garden of the Russian Academy of Sciences, listed in the Red Data Books of Russia
Authors: Shustov M.V. , Mamontov A.K. , Zueva M.A. , Stogova A.V.
Published: December 2023

Many years of experience in preserving species of Siberian flora listed in the Red Data Books of Russia in 2008 and 2023 are analyzed. In total, since 1947, 21 species from 13 families, the geographical points of origin of which are located mainly in Southern Siberia, have been tested on the territory of the botanical and geographical exhibition in the laboratory of natural flora of the GBS RAS. According to the degree of introduction resistance, 90% of species are resistant, weakly resistant and unstable - 10%. In terms of life expectancy under exposure conditions, species growing for more than 20 years predominate - 47.6%. The minimum lifespan ofOxytropis nitensis 2 years. The maximum life expectancy was reached by:Paeonia hybrida- 63 years,Anemonastrum baikalense- 53 years,Erythronium sibiricum- 50 years. The reliability and prospects of preserving rare species of Siberia in the conditions of Moscow are shown.
Ways of efficient use of water in conditions of water resources shortage
Authors: Shokhujaeva Zebo , Mamanazarova Nasiba , Mirjamilova Hulkar
Published: December 2023

The shortage of water from Uzbekistan is becoming increasingly urgent due to global climate change. The demand for water of the population of the Central Asian countries is mainly satisfied at the expense of transboundary rivers. According to research, by 2025, due to climate change and global temperature increase, the reserve of glaciers supplying water to the Amu Darya and Sir Darya rivers is expected to decrease by 15-20%. It has been found that the volume of mountain glaciers is decreasing by 0.2-1 percent per year, and the snow reserves in mountain river basins are decreasing. In order to solve the problems presented in this article, it is necessary to improve the use of water-saving technologies in the irrigation of agricultural crops and fully automate the methods of water consumption calculation, remote control of the channel, recording of water losses in the channel and its prevention. elaborate proposals have been developed.
Ulcus cruris venosum: Shaving-Therapie und Meshgraft-Hauttransplantation
Authors: Juntermanns Benjamin , Kröger Knut , Waldhausen Peter , Gäbel Gabor
Published: December 2023

Das Ulcus cruris venosum ist die häufigste Ulkusform. Ein gutes Wundmanagement in Kombination mit der essenziellen Kompressionstherapie lässt den Großteil der Ulzerationen abheilen. Sollte es unter dieser Therapie nicht zur Abheilung kommen, stellt die operative Therapie mit Ulkusshaving und anschließenden Meshgraft-Hauttransplantation eine gute Therapieoption zur definitiven Wunddeckung dar.
„Bewegt in Balance“ – ein online
durchgeführtes Bewegungsprogramm zur Verringerung von personenbezogenen
Sturzrisikofaktoren älterer Erwachsener
Authors: Kuder Ronja , Mandrysch Julia , Kahlert Daniela
Published: December 2023

Mit zunehmendem Alter steigt die Prävalenz von Stürzen. Etwa ein
Drittel aller selbstständig lebenden über 65-Jährigen
stürzt mindestens einmal pro Jahr. Stürze können sowohl
körperliche Verletzungen wie z. B. (Hüft-)Frakturen als
auch psychische Folgen, wie eine erhöhte Sturzangst, nach sich ziehen.
Evidenzbasierte Bewegungsprogramme, welche die personenbezogenen Risikofaktoren
adressieren, könnten einen vielversprechenden Beitrag zur
Sturzprävention leisten.

Die Intervention „Bewegt in Balance“ wurde dementsprechend auf
Grundlage einer Programmtheorie geplant, bei der die Interventionsinhalte einer
fundierten Wirkungslogik folgen. Das fünfwöchige Programm
beinhaltete dabei eine Kombination aus Gleichgewichts- und Krafttraining und
fand zweimal wöchentlich synchron für jeweils eine Stunde
über ein Online-Portal statt. Zur Evaluation diente ein
prä-post-quasi-experimentelles-Wartekontrollgruppendesign. Hierbei
wurden verschiedene personenbezogene Sturzrisikofaktoren erhoben: die statische
Gleichgewichtsfähigkeit, die Beinkraft und die Sturzangst. Die
Stichprobe umfasste 27 Personen (Mittelwert=70.96 Jahre;
SD=8.89; 55.56 % weiblich).

Die Rangvarianzanalyse ergab für die statische
Gleichgewichtsfähigkeit (modifizierter Romberg-Test: p=.016;
Einbeinstand: p=.046) und die Beinkraft (Aufstehtest: p=.050)
der Interventions- und Kontrollgruppe eine (tendenziell) signifikante
Verbesserung über die Zeit. Rund 54 % der Teilnehmenden aus der
Interventionsgruppe berichteten eine subjektive Verbesserung ihrer
Gleichgewichts- und Kraftfähigkeit infolge des Trainings. Der nicht
nachweisbare Gruppeneffekt des Interventionsprogramms bleibt zu diskutieren. Die
hierfür möglichen inhaltlichen oder auch test-statistischen
Erklärungen, wie beispielsweise die Interventionsdauer oder eine
größere Stichprobe, sollten in zukünftigen Studien
adressiert werden.
VR-Therapie: Herausforderungen bei der Entwicklung eines
Medizinproduktes
Authors: Stemick Judith , Teichmann Laura , Saur Thomas
Published: December 2023

Immersive Virtuelle Realität (VR) wird in der Medizin bereits in
unterschiedlichen Bereichen eingesetzt. Wir als Medizinprodukthersteller haben
uns auf die Entwicklung immersiver VR für die sensomotorische und
kognitive Therapie spezialisiert. Der Artikel soll Herausforderungen
näher beleuchten, welche bei der Entwicklung und Implementierung eines
VR-Therapiesystems aufkommen. Hierbei werden die verschiedenen Herausforderungen
und Lösungsansätze entlang des Entwicklungs- und
Implementationsprozesses beschrieben.

Die größte Herausforderung ist, ein Therapiesystem zu entwickeln,
welches maßgeschneidert auf die Bedürfnisse der Patienten und
Therapeuten ist. Human-centered Design bietet dabei eine gute Grundlage, die
Bedürfnisse von Patienten und Therapeuten von Anfang an in den Fokus zu
stellen. Ein Teil der Lösung besteht darin, im ständigen
Austausch mit klinischen Partnern zu bleiben, um Veränderungen in der
Therapielandschaft mit zu berücksichtigen, sowie Wünsche von
Therapeuten und Patienten für kommende Updates zu sammeln. Weitere
Herausforderungen bilden mögliche Nebenwirkungen der VR, das
Wohlbefinden von Patienten während der Therapie und eine
möglichst intuitive Handhabung des VR-Therapiesystems für den
Therapeuten.

Nach der Entwicklung ist die reibungslose Integration des VR-Therapiesystems in
den Klinikalltag von hoher Bedeutung. Mit Schulungen, Weiterbildungen und
Beratungen durch den firmeneigenen Service kann man Fragen und Anforderungen
schnell lösen. VR-Therapie erweitert die Vielfalt der Therapielandschaft
und kann ein Baustein sein, um die Therapeuten in Kliniken und Praxen nachhaltig
zu entlasten. Um VR-Therapie als festen Bestandteil der Versorgung zu
etablieren, ist langfristig eine Erstattung durch die Kostenträger
erforderlich.
Are Health Care Providers Caring for Pregnant and Postpartum Women Ready to Confront the Perinatal Cannabis Use Challenge?
Authors: Kitsantas Panagiota , Pursell Shannon R.
Published: December 2023

Objective The purpose of this study was to assess health care providers' knowledge and practices related to cannabis use among pregnant and postpartum women.

Study Design A survey of health care providers (n = 75 responders) was conducted across four main regions in the state of Virginia to assess knowledge of adverse health effects associated with perinatal cannabis use, screening tools, follow-up for positive screening, barriers to having discussions about cannabis use, and treatment among pregnant and postpartum women.

Results An astonishing 34.7% of the providers surveyed responded as not being aware of the impacts of cannabis use on the health of the mother and infant, and 66.7% of them reported that they would like some training on feeling comfortable with their knowledge about the impact of perinatal cannabis use on the population they are serving. When asked about providing resources and/or patient education related to cannabis use during pregnancy and/or breastfeeding, 62.7% reported they did not but they would be interested in providing both resources and education. Over one-third of the providers did not have a follow-up process for positive screening. In addition, numerous barriers to asking/screening and/or discussing cannabis use and potential harm reduction methods for the pregnant and postpartum populations emerged such as inadequate or lack of resources for positive screening, lack of knowledge on the topic, unsure about the policies of reporting a positive screening, etc.

Conclusion The findings of this study indicate that health care providers caring for pregnant and postpartum women are not equipped to make appropriate recommendations to patients and guide them through decision-making. Health care providers caring for pregnant and postpartum women need to be knowledgeable on how to best support patients with cannabis use for effective counseling and guidance due to health risks. State policies and resources are needed to ensure training for clinicians on perinatal cannabis.

Key Points
Effect of electron-electron collisions on entrance potential drop in high-mobility 2DEG channels
Authors: Pyshkin P. V. , Yanovsky A. V.
Published: December 2023

Usually, the evidence of viscous hydrodynamic transport of frequently colliding conduction electrons is considered to be the “Gurzhi effect,” which requires the scattering of electrons on the channel walls with momentum loss. However, we demonstrate that expansion of Sharvin’s potential drop directly related to frequent electron-electron collisions can be detected even in channels with ideally smooth walls in a two-dimensional degenerate electron gas (2DEG). In theory, this effect could be experimental evidence of the predicted earlier difference between the relaxation times of the antisymmetric and symmetric momentum distributions attributed to the Pauli principle and topological limitations in 2DEG.
Thermal conductivity in one-dimensional electronic fluids
Authors: Gutman D. B. , Protopopov I. V. , Samanta R. , Mirlin A. D.
Published: December 2023

We study thermal conductivity in one-dimensional electronic fluids combining kinetic [R. Samanta, I. V. Protopopov, A. D. Mirlin, and D. B. Gutman, Thermal transport in one-dimensional electronic fluid, Phys. Rev. Lett. 122, 206801 (2019)] and hydrodynamic [I. V. Protopopov, R. Samanta, A. D. Mirlin, and D. B. Gutman, Anomalous hydrodynamics in one-dimensional electronic fluid, Phys. Rev. Lett. 126, 256801 (2021)] theories. The kinetic approach is developed by partitioning the Hilbert space into bosonic and fermionic sectors. We focus on the regime where the long-living thermal excitations are fermions and compute thermal conductivity. From the kinetic theory standpoint, the fermionic part of thermal conductivity is normal, while the bosonic one is anomalous, that scales as ω–1/3 and thus dominates in the infrared limit. The multi-mode hydrodynamic theory is obtained by projecting the fermionic kinetic equation on the zero modes of its collision integral. On a bare level, both theories agree and the thermal conductivity computed in hydrodynamic theory matches the result of the kinetic equation. The interaction between hydrodynamic modes leads to renormalization and consequently to anomalous scaling of the transport coefficients. In a four-mode regime, all modes are ballistic and the anomaly manifests itself in Kardar-Parisi-Zhang-like broadening with asymmetric power-law tails. “Heads” and “tails” of the pulses contribute equally to thermal conductivity, leading to ω–1/3 scaling of heat conductivity. In the three-mode regime, the system is in the universality class of a classical viscous fluid [Herbert Spohn, Nonlinear fluctuating hydrodynamics for anharmonic chains, J. Stat. Phys. 154, 1191 (2014); O. Narayan and S. Ramaswamy, Anomalous heat conduction in one-dimensional momentum-conserving systems, Phys. Rev. Lett. 89, 200601 (2002)].
Hydrodynamic Navier-Stokes equations in two-dimensional systems with Rashba spin-orbit coupling
Authors: Idrisov Edvin G. , Hasdeo Eddwi H. , Radhakrishnan Byjesh N. , Schmidt Thomas L.
Published: December 2023

We study a two-dimensional (2D) electron system with a linear spectrum in the presence of Rashba spin-orbit (RSO) coupling in the hydrodynamic regime. We derive a semiclassical Boltzmann equation with a collision integral due to Coulomb interactions on the basis of the eigenstates of the system with RSO coupling. Using the local equilibrium distribution functions, we obtain a generalized hydrodynamic Navier–Stokes equation for electronic systems with RSO coupling. In particular, we discuss the influence of the spin-orbit coupling on the viscosity and the enthalpy of the system and present some of its observable effects in hydrodynamic transport.
Dynamics of skyrmion contraction and expansion in a magnetic film
Authors: Chudnovsky Eugene M.
Published: December 2023

Contraction and expansion of skyrmions in ferromagnetic films are investigated. In centrosymmetric systems, the dynamics of a collapsing skyrmion is driven by dissipation. The collapse time has a minimum on the damping constant. In systems with broken inversion symmetry, the evolution of skyrmions toward equilibrium size is driven by the Dzyaloshinskii–Moriya interaction. Expressions describing the time dependence of the skyrmion size are derived and their implications for skyrmion-based information processing are discussed.
Nonlinear dynamics of magnetic multilayers. II. Antiferromagnetic interlayer interaction
Authors: Kovalev A. S. , Ezerskaya E. V. , Krbashyan L. R.
Published: December 2023

An essentially nonlinear dynamics with a high level of excitation of a magnetic multilayer consisting of two nanolayers with a nonisotropic antiferromagnetic interaction between the layers is considered. The theoretical study was carried out within the framework of discrete Landau–Lifshitz equations without damping. Exact solutions of this integrable system are obtained for all types of nonlinear excitations. They are reduced to the nonlinear superposition of precessional and nutational oscillations of coupled macroscopic magnetic moments. The dependences of the oscillation frequencies of the moments on the total energy of the system and its magnetization along a preferred axis, which are integrals of motion, are found. In different ranges of values of these integrals, an exact, approximate, and qualitative study of the problem was carried out, which was accompanied by a direct numerical analysis of the initial equations. Attention is drawn to the possibility of significantly different levels of excitations of identical layers. Finding the relationship between the dynamic characteristics of excitations (their frequencies) and their integral characteristics (energy and magnetization) can be useful in studying multilayer systems by resonance methods.
Design of a multi-direction piezoelectric and electromagnetic hybrid energy harvester used for ocean wave energy harvesting
Authors: Chen Liang , Li Chong , Fang Jiwen
Published: December 2023

Ocean waves contain a great deal of energy, and the collection and utilization of wave energy is of great significance for sustainable development. In this paper, a multi-direction piezoelectric and electromagnetic hybrid energy harvester (PEHEH) based on magnetic coupling is proposed that can collect low frequency vibration energy from multiple directions. The proposed PEHEH combines piezoelectricity and electromagnetism through magnetic coupling to collect energy in the same excitation. The mechanical model of the PEHEH is established, and finite element simulation software COMSOL and computational fluid dynamics are used to analyze and verify the feasibility and practicability of the PEHEH structure. An experimental platform is built to test the output performance of the PEHEH. The results show that the maximum energy generated by PEHEH is 19.4 mW when the magnetic distance is 16 mm and the excitation frequency is 9 Hz. The hybrid energy harvester can light 56 light emitting diodes, which verified the feasibility of practical application. Therefore, the proposed hybrid energy harvester can effectively collect low-frequency wave energy and has a broad application prospect as a power source for low-power electronic devices.
Realization of an ultra-thin absorber with fragmented magnetic structure at L-, S-, and partial C-bands
Authors: E Liujia , Liu Zhongqing , Zhang Jingwei , Xu Zhaoxuan , Yuan Zhenliang , Mei Zhonglei , Niu Tiaoming
Published: December 2023

In this paper, an ultra-thin absorber with a total thickness of 9.2 mm is designed and verified at the frequency band of 1–5.34 GHz. The absorber is composed of a layer of metasurface, multi-layered magnetic substrate, a layer of fragmented magnetic structure obtained by improved MOEA/D-GO (Multi-Objective Evolutionary Algorithm based on Decomposition combined with Enhanced Genetic Operators), and a copper back plate. The absorber is achieved by two steps. First, we designed and measured an ultra-thin absorber at 0.78–2.04 GHz by adding a layer metasurface onto the top of a basic multi-layer absorber composed of magnetic materials. The fractional bandwidth (FBW) of the absorber is 89.4%, and the electrical thickness is only 0.024λ0 at the lowest operating frequency. Second, to broaden the bandwidth, we use an improved MOEA/D-GO to optimize one magnetic layer of the absorber. The working frequency band of the optimized absorber is 1–5.34 GHz, covering L- (1–2 GHz), S- (2–4 GHz), and partial C-bands (4–8 GHz). Furthermore, we modified the structure of the metasurface to make the absorber polarization-independent. The FBW of the final absorber is 136.4%, and the electrical thickness is 0.031λ0 at the lowest operating frequency. The prototype of the absorber is measured, and the experimental results agree well with the simulated performance. The results show that the improved MOEA/D-GO can be used to design and optimize sophisticated electromagnetic (EM) structures with the predesigned properties, and the absorber with ultrathin thickness and light weight verified in this paper have great application potentials in EM compatibility, EM shielding, and radar cross section reduction at the low bands of the microwave spectrum.
Turbulent skin-friction drag reduction by annular dielectric barrier discharge plasma actuator
Authors: Zheng Borui , Lin Deling , Qi Shaojie , Hu Yuzhe , Jin Yuanzhong , Chen Quanlong , Bian Dongliang , Yan Rihua
Published: December 2023

Reducing turbulent skin friction drag is a fundamental goal for aircraft transportation to conserve energy and decrease emissions. We introduce an annular dielectric barrier discharge plasma actuator (A-DBD-PA) that merges the advantages of near-wall micro-blowing with pulsed plasma flow control to reduce turbulence drag. Wind tunnel experiments on a flat plate assessing the performance of A-DBD-PA revealed that the wall-normal jet on the symmetry plane is critical for turbulent drag reduction in an unsteady flow field. As the duty cycle of plasma actuation increases, it steadies the wall-normal jet, which diminishes shear stress and velocity fluctuations in the boundary layer. This enhanced steadiness fosters induced vortices' formation and evolution, directly impacting the drag reduction rate. Duty cycles below 50% yield a limited drag reduction rate because the airflow's viscous effects predominate over the influence of plasma actuation. Conversely, duty cycles above 50% enhance the interaction of induced vortices, contributing to a stronger disturbance and more effective control, optimizing drag reduction rate up to a maximum of 5.197%.
The intelligent optimization of perforation cluster locations incorporating the fiber optics monitoring results
Authors: Li Lizhe , Wang Bo , Ge Hui , Zhou Hang , Wang Yunjin , Zhang Li , Zhou Fujian
Published: December 2023

During horizontal well multi-stage fracturing (HWMF), superfractures are often identified. To promote the uniform propagation of multiple fractures, it is necessary to finely optimize the perforation cluster locations based on the geological and engineering parameters. This work proposes an efficient method to design the perforation cluster locations in consideration of the geoengineering sweet spots with similar mechanical properties. Well log data and the precise fiber optics (FO) monitoring results are combined to find the main influencing factors. The principal component is conducted by introducing correlation analysis and Random Forest. Moreover, the K-means++ clustering method is used to evaluate reservoir quality. The fracturing sweet index (FSI) is proposed to measure the fracturing performance of each category quantitatively. The proposed workflow is effectively validated by two production scenarios. Moreover, the workflow can automatically evaluate reservoir quality based on intelligent clustering methods. Compared with the original design, the updated design lowers the gap among multiple fractures within one stage and increases the well production by 20%–50%. This work is beneficial for the on-site treatment of its feasibility and generalizability.
Magnetic sorting of circulating tumor cells based on different-level antibody expression using a divergent serpentine microchannel
Authors: Ebrahimi Sina , Rostami Zohreh , Alishiri Mojgan , Shamloo Amir , Hoseinian Seyyed Mohammad Ali
Published: December 2023

The privilege of early cancer detection is entangled with many people's lives. Thus, providing an efficient tool to analyze circulating tumor cells (CTCs) would be an immense asset. In this study, a CTC sorting mechanism is introduced by classifying CTCs based on their EpCAM (epithelial cell adhesion molecule) level, a cell surface marker applicable to cancer staging. For this purpose, an integrated microfluidic chip was designed to focus and separate CTCs from blood cells in a divergent serpentine microchannel, and simultaneously, sort CTCs into three categories [low-EpCAM (N1 = 406), medium-EpCAM (N2 = 693), and high-EpCAM (N3 = 1693)] using a magnetic field. The velocity optimizations, using finite element method (FEM), provided a focusing efficiency above ∼95% (for different cell lines) and a CTC separation efficiency above 92%, validated with our experimental results in the passive section. Furthermore, by optimizing the characteristics of the magnet (through several simulations), three optimum designs were achieved, featuring microchannel lengths of 5, 15, and 30 mm in the active section. The innovative approach introduced in this study integrates microfluidic chips, enabling a one-time, high-throughput process with a recovery rate exceeding 99%. This not only reduces costs and runtime but also enhances sorting efficiency for monitoring the stage of cancer progression.
Spin model for the honeycomb NiPS3
Authors: Mellado Paula
Published: December 2023

In the Van der Waals material NiPS3, Ni atoms have spin S = 1 and realize a honeycomb lattice. Six sulfur atoms surround each Ni and split their d manifold into three filled and two unfilled bands. Aimed to determine the spin Hamiltonian of NiPS3, we study its exchange mechanisms using a two-band half-filled Hubbard model. Hopping between d-orbitals is mediated by p orbitals of sulfur and gives rise to bilinear and biquadratic spin couplings in the limit of strong electronic correlations. The microscopic model exposed a ferromagnetic biquadratic spin interaction K1, allowing the completion of a minimal J1−J3−K1 spin Hamiltonian for NiPS3. In bulk, a ferromagnetic first nearest neighbor J1 and a more significant antiferromagnetic third nearest neighbor spin coupling J3 agreed with the literature, while in monolayer, J1 is positive and very small in comparison. Using a variational scheme, we found that a zig–zag antiferromagnetic order is the ground state of bulk samples. The zig–zag pattern is adjacent to commensurate and incommensurate spin spirals, which could hint at the puzzling results reported in NiPS3 monolayers.
Vortex dynamics of accelerated flow past a mounted wedge
Authors: Kalita Jiten C. , Kumar Pankaj
Published: December 2023

This study is concerned with the simulation of a complex fluid flow problem involving flow past a wedge mounted on a wall for channel Reynolds numbers Rec = 1560, 6621, and 6873 in uniform and accelerated flow medium. The transient Navier–Stokes (N–S) equations governing the flow have been discretized using a recently developed second order spatially and temporally accurate compact finite difference method on a nonuniform Cartesian grid by the authors. Almost all the flow characteristics of a well-known laboratory experiment of Pullin and Perry [“Some flow visualization experiments on the starting vortex,” J. Fluid Mech. 97(2), 239–255 (1980)] have been captured by our numerical simulation, and we provide a qualitative and quantitative assessment of the same. Furthermore, the influence of the parameter m, controlling the intensity of acceleration, has been discussed in detail along with the intriguing consequence of non-dimensionalization of the N–S equations pertaining to such flows. The simulation of the flow across a time span significantly greater than the aforesaid lab experiment is the current study's major achievement. Meanwhile, a grid independence study performed in the process confirmed that our simulation is devoid of any under-resolution or numerical artifact. For the accelerated flow, the onset of shear layer instability leading to a more complicated flow toward transition to turbulence has also been aptly resolved. The quality of our simulation is validated by the close similarity of our simulation to the high Reynolds number experimental results of Lian and Huang [“Starting flow and structures of the starting vortex behind bluff bodies with sharp edges,” Exp. Fluids 8(1–2), 95–103 (1989)] for the accelerated flow across a typical flat plate. All three steps of vortex shedding, including the exceedingly intricate threefold structure, have been captured quite efficiently.
Characteristics and interactions of fluctuation velocities, saltation mass flux, and temperature in the atmospheric surface layer
Authors: Mei Ao , Huang Chentao , Ru Yanyun , Wei Xu
Published: December 2023

The essence of wind-blown sand movement is a particle movement system driven by high Reynolds number wall turbulence in the atmospheric surface layer (ASL). Understanding this phenomenon is crucial as the law and mechanism of sand movement have not been effectively revealed at present. In this study, we utilize the high-frequency time series data from the Oceano site, a renowned location for such studies, which includes streamwise wind velocity (u), wall-normal wind velocity (w), temperature (T), and total saltation mass flux (q) to delve deeper into wind-blown sand movement. The results indicate a positive correlation between T and w. Interestingly, this correlation not only escalates with height but also intensifies with the increase of the stratification stability parameters (z/L). Sand influences the intensity ratio of each quadrant to Reynolds stress without altering the time ratio. Both the ejection and sweep processes correlate well with z/L. Similarly, q also exhibits a good correlation with z/L. The buoyancy's impact on the low-frequency fluctuations of q might be through its effect on the low-frequency fluctuations of w, enhancing the sand transport capacity of w. This discovery holds profound implications for the study of two-phase flow in ASL and the precise prediction of surface sediment transport.
Spatiotemporal evolution of particle puffs in transitional channel flow
Authors: Perrone D. , Kuerten J. G. M. , Ridolfi L. , Scarsoglio S.
Published: December 2023

We study the shape evolution of puffs composed of tracers advected in a transitional channel flow. We perform a direct numerical simulation of a spatially evolving channel flow, where the inflow condition is given by a solution of the Orr–Sommerfeld equation and the flow evolves through all stages of transition up to fully developed turbulence. In this setting, we release spherical puffs of particles and track their evolution using measures derived from their approximation as ellipsoids. By varying the initial position of puffs, we characterize the spatial non-homogeneity of the flow, with respect to both the distance from the wall and, most importantly, the streamwise coordinate along which the flow evolves. Furthermore, we assess the influence of scale-dependent phenomena on puff shapes by varying the initial size of the clouds of particles. The present approach explores the interaction between flow features and advected Lagrangian structures. Additionally, it reveals the interplay between flow scales and how their balance changes during transition, where the intermittency causes large puffs to be much less elongated than smaller puffs independently of the distance from the walls.
Verification and validation for large eddy simulation of the turbulent flow around an underwater entity
Authors: Hu Yijing , Wu Qin , Zhang Housheng , Huang Biao , Wang Guoyu
Published: December 2023

The objective is to analyze the errors and uncertainty in the simulation results of the complex, unsteady turbulent flow and vortices. The implicitly filtered large eddy simulation (LES) with the boundary data immersion method is used to investigate the transient turbulent flow around a fully appended underwater entity model (SUBOFF) proposed by Groves et al. [Geometric Characteristics of DARPA Suboff Models: (DTRC Model Nos. 5470 and 5471) (David Taylor Research Center, 1989)] with emphasis on verification and validation. As for the verification, the five-equation method is used to assess the LES error, including the modeling error and numerical error in the transient flow. They offset each other, leading to a small total error. As for the validation, it has been achieved in the most area when the experimental result is located at the band of ysim ± UV (ysim is the simulation result, and UV is the validation uncertainty). There is a strong relationship between the validation uncertainty and the complex vortex interaction. The validation uncertainty becomes significant, which means less accuracy of the simulation result, within the tip flow region, adverse pressure gradient region, tip vortex interacting with the boundary layer region and shear layer region. Most all of these regions occur behind the appendage and at the shape changing position of the SUBOFF.
Statistical investigations of profile error impact on flow and performance of a low-pressure turbine cascade
Authors: Chen Zeshuai , Luo Jiaqi , Xia Zhiheng , Zou Zhengping , Du Pengcheng , Liu Feng
Published: December 2023

Profile error impacts on turbomachinery flow and blade performance have been attracting widespread attention. In the study, the characteristics of profile error of about one thousand real low-pressure turbine blades are extracted. Sensitivities of total pressure loss coefficient (ζ), outflow angle (β), and Zweifel lift coefficient (zw) of the blade to the basis modes of profile error are calculated. Flow solutions of the blades considering specified basis modes with high sensitivities illustrate that profile error contributes much to the variations of transition onset and flow acceleration on the suction side and flow mixing intensity in the wake. Uncertainty quantification of performance changes is then implemented by the method of moment (MM) using second-order sensitivities. With only 5% computational cost of that by Monte Carlo simulation (MCS), the MM-based statistical results are close to MCS ones with maximum relative error not exceeding 1.07%. The statistical results reveal that the variations of both β and zw are linearly dependent, whereas the variation of ζ is nonlinearly dependent on profile error. As the variation range of profile error increases, the standard deviation and skewness increase, indicating that the performance is more dispersive and the nonlinear dependence of ζ on profile error is intensified. Finally, the MCS flow fields are analyzed. Statistical shear stress near the leading edge and transition onset, statistical boundary layer momentum thickness near transition onset, statistical intermittency near transition onset, and statistical entropy in the wake are more considerable. The impact mechanisms of profile error on turbine flow and performance changes are demonstrated.
Achieving high quality factor and enhanced thermoelectric performance in polycrystalline SnS by Ag doping and Se alloying
Authors: He Zhengmin , Zhu Jianglong , Su Wenjun , An Xiang , Zhao Canyang , Yuan Wei , Lin Liwei , Ang Ran
Published: December 2023

The polycrystalline SnS with a similar layered crystal structure and band structure to SnSe exhibits enormous commercial thermoelectric potential due to its lower cost and environmentally friendly characteristics. However, the wider bandgap of SnS leads to low carrier concentration and inferior electrical transport performance. The two-dimensional interlayer hinders carrier transport, leading to interesting and mysterious anisotropic thermoelectric properties. Herein, we reported the optimized electron–phonon transport in anisotropic polycrystalline SnS by Ag doping and Se alloying, realizing a high quality factor B by multiple strategies of optimizing carrier concentration, modifying band structure, and introducing various defects; further potential performance is predicted by the single parabolic band model. Specifically, Ag-doped SnS not only significantly increases the carrier concentration and weighted mobility μw in both directions but also induces multi-scale precipitates proven by the Debye–Callaway model to suppress phonon transport. Moreover, additional Se alloying optimizes the electronic band structure and increases the Seebeck coefficient, further improving μW and boosting the maximum power factor to ∼3.72 μW cm−1 K−2 at 873 K in the out-of-plane direction. Consequently, the synergistic optimization of carrier and phonon transport achieved a high B of 0.7 and a maximum zTmax of ∼0.8 at 873 K in Ag0.02Sn0.98S0.99Se0.01. Additionally, the high B predicted a high zTmax∼1.5 based on optimized carrier transport characteristics, demonstrating the potential great-performance polycrystalline SnS. This work provides a promising avenue for optimizing the zT of polycrystalline SnS by transport engineering.
Measuring coating layer shape in arbitrary geometry
Authors: Song Jisoo , Yu Dongkeun , Jo Euihyun , Nam Jaewook
Published: December 2023

Coating processes are typically analyzed on systems with flat substrates, such as the Landau–Levich–Derjaguin configuration in dip coating. However, actual applications often exhibit a much wider variety of geometries. For example, dip coating is also employed as a batch process with three-dimensional substrates. After the batch dip coating process, the coating layer is likely to exhibit irregular geometries near the lower edge of the substrate; the substrate profile is not flat, and the fluid can form overhangs depending on process conditions and rheological properties. These irregularities make it impossible to define layer shape measures, such as average thickness and roughness, in traditional ways. In this study, we propose generalized measures to overcome this issue by using offset distance and curve similarity. Our measures can quantify the shape of the coating layers in arbitrary geometries and are, therefore, robust against irregularities. We applied our measures to analyze the formation of external electrodes on multi-layer ceramic capacitors by batch dip coating. Coating layer profiles during the process were acquired for the analysis using a simple machine vision technique. As a result, differences in the coating layer shapes between fluids with different rheological properties were quantified. The results show that our measures can be used to compare coating qualities in arbitrary geometries for designing optimal process conditions.
Coupled atmospheric chemistry, radiation, and dynamics of an exoplanet generate self-sustained oscillations
Authors: Luo Yangcheng , Hu Yongyun , Yang Jun , Zhang Michael , Yung Yuk L.
Published: December 2023

Nonlinearity in photochemical systems is known to allow self-sustained oscillations, but they have received little attention in studies of planetary atmospheres. Here, we present a unique, self-oscillatory solution for ozone chemistry of an exoplanet from a numerical simulation using a fully coupled, three-dimensional (3D) atmospheric chemistry-radiation-dynamics model. Forced with nonvarying stellar insolation and emission flux of nitric oxide (NO), atmospheric ozone abundance oscillates by a factor of thirty over a multidecadal timescale. As such self-oscillations can only occur with biological nitrogen fixation contributing to NO emission, we propose that they are a unique class of biosignature. The resulting temporal variability in the atmospheric spectrum is potentially observable. Our results underscore the importance of revisiting the spectra of exoplanets over multidecadal timescales to characterizing the atmospheric chemistry of exoplanets and searching for exoplanet biosignatures. There are also profound implications for comparative planetology and the evolution of the atmospheres of terrestrial planets in the solar system and beyond. Fully coupled, 3D atmospheric chemistry-radiation-dynamics models can reveal new phenomena that may not exist in one-dimensional models, and hence, they are powerful tools for future planetary atmospheric research.
A theoretical perspective on Waddington’s genetic assimilation experiments
Authors: Raju Archishman , Xue BingKan , Leibler Stanislas
Published: December 2023

Genetic assimilation is the process by which a phenotype that is initially induced by an environmental stimulus becomes stably inherited in the absence of the stimulus after a few generations of selection. While the concept has attracted much debate after being introduced by C. H. Waddington 70 y ago, there have been few experiments to quantitatively characterize the phenomenon. Here, we revisit and organize the results of Waddington’s original experiments and follow-up studies that attempted to replicate his results. We then present a theoretical model to illustrate the process of genetic assimilation and highlight several aspects that we think require further quantitative studies, including the gradual increase of penetrance, the statistics of delay in assimilation, and the frequency of unviability during selection. Our model captures Waddington’s picture of developmental paths in a canalized landscape using a stochastic dynamical system with alternative trajectories that can be controlled by either external signals or internal variables. It also reconciles two descriptions of the phenomenon—Waddington’s, expressed in terms of an individual organism’s developmental paths, and that of Bateman in terms of the population distribution crossing a hypothetical threshold. Our results provide theoretical insight into the concepts of canalization, phenotypic plasticity, and genetic assimilation.
Real-Time Observation of Instantaneous ac Stark Shift of a Vacuum Using a Zeptosecond Laser Pulse
Authors: Su 苏 Dandan 丹丹 , Jiang 江 Miao 淼
Published: December 2023

Based on the numerical solution of the time-dependent Dirac equation, we propose a method to observe in real time the ac Stark shift of a vacuum driven by an ultra-intense laser field. By overlapping the ultra-intense pump pulse with another zeptosecond probe pulse whose photon energy is smaller than 2mc
2, electron–positron pair creation can be controlled by tuning the time delay between the pump and probe pulses. Since the pair creation rate depends sensitively on the instantaneous vacuum potential, one can reconstruct the ac Stark shift of the vacuum potential according to the time-delay-dependent pair creation rate.
Real supersymmetric solutions of
(3,2)
signature five-dimensional supergravity
Authors: Farotti D , Gutowski J B , Sabra W A
Published: December 2023

We classify supersymmetric solutions of D = 5

(
3
,
2
)

signature supergravity with either vanishing or imaginary gauge coupling constant preserving the minimal N = 2 supersymmetry. We prove that the geometry of such solutions is characterized by a nilpotent integrable endomorphism, and obtain the necessary and sufficient conditions on the fluxes imposed by supersymmetry. We also construct examples of supersymmetric domain wall solutions for which the nilpotent integrable endomorphism is associated with a Killing–Yano two-form, as well as a new descendant ‘preon’ solution which preserves N = 6 supersymmetry. This is notable as such N = 6 descendant solutions do not exist in the standard signature D = 5 supergravity.
Fraunhofer approximation of Fresnel integrals
Authors: Dupraz K , Dupuis G , Martens A , Rax J-M , Zomer F
Published: December 2023

A method to derive the Fraunhofer diffraction integral by making use of the theory of distributions is presented. With respect to standard textbooks, the pedagogical benefit of this method is that it uniquely uses the far-field approximation of the Fresnel diffraction integral. An operator representation of Fresnel diffraction is also derived.
Ultrathin Al2O3 interfacial layer for Hf0.5Zr0.5O2-based ferroelectric field-effect transistors
Authors: Lee Jehoon , Eom Deokjoon , Lee Heesoo , Lee Woohui , Oh Joohee , Park Changyu , Kim Hyoungsub
Published: December 2023

In this study, the effects of an Al2O3 interfacial layer (IL) on the characteristics of ferroelectric field-effect transistors (FeFETs) with Hf0.5Zr0.5O2 (HZO) gate dielectrics on Si substrates were investigated. FeFETs with HZO gate dielectrics have gained considerable attention owing to their compatibility with modern fabrication processes and scalability. However, during HZO deposition on Si substrates, an ultrathin metal silicate IL with a low dielectric constant is formed in an uncontrolled manner, leading to a significant voltage drop and the generation of interface traps during device operation. To address this issue, an ultrathin Al2O3 IL with a thickness less than 2 nm was introduced between the HZO film and Si substrate via in situ atomic layer deposition. The impact of this IL on a memory window (MW) and endurance characteristics was evaluated by comparing the devices with and without an intentional Al2O3 IL. The obtained results revealed that the Al2O3 IL effectively suppressed the interface trap generation, expanded the MW, and enhanced the transistor endurance characteristics. This described approach can be potentially used for improving the reliability of FeFETs fabricated on Si substrates.
Unusual magnetic interaction in CrTe: insights from machine-learning and empirical models
Authors: Zhang F , Zhang J , Fang D , Zhang Y , Wang D
Published: December 2023

Chromium telluride (CrTe) has received much attention due to its small magnetic anisotropy, which hosts the potential for complex magnetic structures. However, its magnetic properties have been relatively unexplored with numerical simulations, as the magnetic interactions inside are quite unusual. In this study, we employ both a machine-learning model and an empirical model to investigate the magnetic phase transitions of bulk and monolayer CrTe, revealing the existence of unusual magnetic interaction, which can be captured by the machine-learning model but not the simple empirical model. Furthermore, our results also demonstrate that magnetic moments further apart exhibit stronger interactions than those in closer proximity, deviating from typical behavior.