bluuebunny/crossref_metadata_2025 huggingface dataset:
Harms Associated with Tracheal Reintubation After Unplanned Extubation: A Retrospective Cohort Study
Authors: Malone Mathew P. , Harwayne-Gidansky Ilana , Sanders Ronald C. , Napolitano Natalie , Pham Jennifer , Polikoff Lee , Register Melinda , Tarquinio Keiko M. , Shults Justine , Krawiec Conrad , Mallory Palen , Breuer Ryan K. , Shenoi Asha N. , Wollny Krista , Parsons Simon J. , Kandil Sarah B. , Pinto Matthew , Gladen Kelsey M. , Dewan Maya , Graciano Ana Lia , Nett Sholeen , Giuliano John S. , Krishna Ashwin S. , Ducharme-Crevier Laurence , Talukdar Andrea , Lee Jan Hau , Miksa Michael , Lee Anthony , Ahmed Aziez , Page-Goertz Christopher , Jung Philipp , Scott Briana L. , Kelly Serena P. , Al-Subu Awni , Spear Debbie , Allen Lauren , Sizemore Johnna , Kasagi Mioko , Nagai Yuki , Toal Megan , Biagas Katherine , Nadkarni Vinay , Nishisaki Akira ,   for the National Emergency Airway Registry for Children (NEAR4KIDS) Pediatric Acute Lung Injury Sepsis Investigators (PALISI) Network
Published: July 2024

Objective This study evaluates the clinical harm associated with tracheal intubation (TI) after unplanned extubation (UE) in the pediatric intensive care unit (ICU). We hypothesized that TI after UE is associated with a higher risk of adverse airway outcomes (AAOs), including peri-intubation hypoxia.

Methods A total of 23,320 TIs from 59 ICUs in patients aged 0 to 17 years from 2014 to 2020 from the National Emergency Airway Registry for Children (NEAR4KIDS) database were evaluated. AAO was defined as any adverse TI-associated event and/or peri-intubation hypoxia (SpO2 < 80%). UE trends were assessed over time. A multivariable logistic regression model was developed to evaluate the association between UE and AAO, while controlling for patient, provider, and practice confounders.

Results UE was reported as TI indication in 373 (1.6%) patients, with the proportion increasing over time: 0.1% in 2014 to 2.8% in 2020 (p < 0.001). TIs after UE versus TIs without preceding UE were more common in infants (62 vs. 48%, p < 0.001), males (63 vs. 56%, p = 0.003), and children with a history of difficult airway (17 vs. 13%, p = 0.03). After controlling for potential confounders, TI after UE was not significantly associated with AAO (adjusted odds ratio [aOR]: 1.26, 95% confidence interval [CI]: 0.99–1.62, p = 0.06). However, TI after UE was significantly associated with peri-intubation hypoxia (aOR: 1.35, 95% CI: 1.02–1.79, p = 0.03).

Conclusions UE is increasing as an indication for TI, and is more common in infants and children with a history of difficult airway. As TI after UE was associated with increased peri-intubation hypoxia, future study should focus on identifying causality and mitigating peri-intubation risk.
Design and simulation of sun position sensors for space applications: A comparative study
Authors: Díaz Salazar Martha , Kondratiuk Nadia , Moreno Analía , Martínez Bogado Mónica , Pavoni Oliver Sonnia , Tamasi Mariana
Published: July 2024

Sun position sensors are used in space applications as part of the attitude determination and control system. The aim of this work is to describe the design process of single and dual axis sun position sensors based on a photodiode array detector and a window to limit and direct the light that reaches the detector. The design process involves choosing the sensor architecture, modeling its output, and then evaluating the model through simulation. Six architectures, with different configurations and geometries for both the detector and window, were modeled and compared. To evaluate the model and performance of the sensor, a program was developed, and simulations were made varying the window height and size as well as the photodiode size. From the simulations performed, we concluded that for each design, the key factors that influence the sensitivity and field of view performance are the window height and window or photodiode size, depending on the sensor configuration. From the comparison across architectures, the detector configuration, as well as the window geometry, influences the sensitivity and linearity of the response for similar conditions of operation. The two-quadrant detector configuration offers a better sensitivity than the triangular photodiode configuration. For a better linearity of the output, a square window is preferred. This comparative study is part of the development of new products for space applications by the National Atomic Energy Commission and contributes to the Argentinian National Space Plan.
Numerical analyses of water swirls in aquaculture tanks
Authors: Li Zhisong , Guo Xiaoyu
Published: July 2024

Water swirls were observed in both model and prototype aquaculture tanks with bottom drains. This phenomenon was seldom replicated in studies of flow fields of water in aquaculture tanks with computational fluid dynamics. A commonality of these studies is that the linear eddy-viscosity turbulence models were employed. This study delves into the water swirls from the aspect of the generation of the turbulence kinetic energy; both the linear and nonlinear eddy-viscosity turbulence models are used, as well as a Reynolds stress turbulence model. A novel identification method is utilized to pinpoint vortex structures. Numerical results affirm the outstanding performance of the Reynolds stress model to estimate the flow fields of water in aquaculture tanks. Both the linear and nonlinear eddy-viscosity models overestimate the kinetic turbulence energy in the stagnation zone of swirls. The overestimation can be restrained by including the effect of the streamline curvature correction (SCC) to the turbulence production term. Even so, the SCC does not help to improve the estimating accuracy between the Reynolds stress tensor and the mean rate-of-strain tensor. While the nonlinear model offers some improvements, the Reynolds stress model provides a more effectvie solution. After that, we calculate the flow fields of water in aquaculture tanks with different inlet–outlet configurations with the Reynolds stress turbulence model. Both the vertical and horizontal scales of water swirls increase with inlet velocities and Froude numbers, where the Froude number is based on the bottom draining velocity and the water depth above the bottom drain. The vertical distributions of the water residence time in aquaculture tanks are shown to improve the design of tanks.
Is journal prestige indicator equivalent of money for humans?
Authors: Krawczyk Malgorzata J. , Malarz Krzysztof
Published: July 2024

In this paper, we investigate the time evolution of the rank correlation coefficients of the prestige indicators of the journals (such as Scimago Journal Rank) over 21 years, for 9856 journals in various disciplines. The observed dependencies do not differ qualitatively from those observed for the time evolution of the ranking correlations in wealth rheology among the richest people recently found by Burda et al. [Entropy 23, 842 (2021)], but quantitatively the changes in rank correlations for human wealth are much stronger than in the coefficients measuring the prestige of journals. In terms of Kendall’s rank correlation coefficients, disciplines “Agricultural and Biological Sciences” and “Earth and Planetary Science” are the most typical, meaning that the time evolution of their rank correlation coefficient based on Scimago Journal Rank is closest to the time evolution of an average over all disciplines. The time evolution of the mean value of the overlap ratio is closest to the time evolution of the overlap ratio for “Psychology” and “Physics and Astronomy” disciplines. The Kendall rank correlation coefficients and the overlap ratio decrease nearly linearly over time, except for the first year, where their decay is significantly faster. The analogy between human wealth and the prestige indicators of journals is strengthened by performing a Monte Carlo simulation of the time evolution of the probability distribution function of Scimago Journal Rank. The simulation is based on a simple model of economic systems. Due to the different coverage of the journals in Scimago Journal & Country Rank and Web of Science, the identically defined measures based on the data in these databases are different.
Local bandgap narrowing in the forming state of threshold switching materials
Authors: Shiojima Kenji , Kawai Hiroki , Kawasumi Yuto , Takehira Hiroshi , Wakisaka Yuki , Imabayashi Hiroki , Iwasaki Takeshi , Komatsu Katsuyoshi , Daibou Tadaomi
Published: July 2024

Threshold switching (TS) materials, such as amorphous chalcogenide, have received significant attention for their application in storage class memory and in-memory computing. These materials contribute to efficient data processing and reduced power consumption in data centers. The initial switching process after fabricating a TS device, known as “forming,” has a profound impact on its subsequent TS behavior. However, it remains unclear how TS materials undergo changes in their atomic and electronic structures during the forming process. Consequently, the key factors that govern TS behavior remain obscure, necessitating a deeper understanding of the underlying physics behind TS phenomena. In this Letter, we investigated the forming state of the TS material AlTeN by combining scanning internal photoemission microscopy (SIPM) and ab initio calculations. Thanks to nondestructive evaluation by SIPM measurements, we observed local bandgap narrowing of AlTeN after its forming process. This is an experimental demonstration showing the presence of nuclei of the conductive filament formed in its ON state. Moreover, we conducted an ab initio calculation to reveal the origin of bandgap narrowing. We applied strong electrothermal stresses to the AlTeN model by ab initio molecular dynamics simulation with high electronic and lattice temperatures. By quenching from the electrothermal stress conditions, we reproduced an experimentally observed forming state with a narrowed bandgap. Analysis of the electronic structures of the forming state revealed that the origin of bandgap narrowing is the generation of the valence band top and conduction band bottom stemming from the increased homopolar bonds.
Interactions of laser-driven tin ejecta microjets over phase transition boundaries
Authors: Saunders Alison M. , Sun Yuchen , Horwitz Jeremy A. K. , Ali Suzanne J. , Eggert Jon H. , Mackay Kyle K. , Morgan Brandon E. , Najjar Fady M. , Park Hye-Sook , Ping Yuan , Pino Jesse
Published: July 2024

Ejecta microjets offer an experimental methodology to study high-speed particle laden-flow interactions, as microjets consist of millions of particulates traveling at velocities of several kilometers per second and are easily generated by most common shock drives. Previous experiments on the OMEGA Extended Performance laser found that collisions between two counter-propagating laser-driven tin ejecta microjets varied as a function of drive pressure; jets generated near shock pressures of 10 GPa passed through each other without interacting, whereas jets generated at shock pressures of over 100 GPa interacted strongly, forming a cloud around the center interaction point. In this paper, we present a more systematic scan of tin ejecta microjet collisions over intermediate pressure regimes to identify how and at what shock pressure interaction behavior onsets. Radiographs of interacting microjets at five different laser drive energies qualitatively demonstrate that interaction behavior onsets slowly as a function of laser drive energy. Quantitative mass and density metrics from each radiograph provide trends on jet characteristics and collisional mass dispersion. It is observed that jetting mass, jet densities, and mass dispersion increase with increasing drive pressures and that the increased jet density at the higher drive energies may account for the increased mass dispersion. This work provides an important step in the understanding of tin ejecta microjet collisions and paves the way for future studies on the physics dominating high-speed particle-laden flow interactions.
Linearly polarized GaN micro-LED with adjustable directional emission integrated with a continuous metasurface
Authors: Zhang Hanbin , Wang Hancheng , Du Jian , Chen Wenhao , Wang Jin , Xue Junjun , Zhi Ting
Published: July 2024

Traditional LEDs emit light that exhibits incoherence and displays a Lambertian distribution. To achieve linearly polarized (LP) light and control the emission direction, a variety of optical components are required to be stacked, which is unsuitable for compact applications and results in low deflection efficiency. Here, we propose and and numerically simulate a novel single-chip micro-resonant cavity LED (micro-RCLED) device that generates directional LP light by integrating a continuous metasurface. This device includes a bilayer grating at the GaN layer's bottom, providing high transverse electric (TE) reflectivity above 89.5% and an extinction ratio exceeds 57 dB at 500 nm. The top distributed Bragg reflector (DBR) and the bilayer grating together constitute a TE mode Fabry–Pérot resonant cavity. This not only promotes the emission of the TE wave, but also guarantees its collimation with the appropriate phase, thereby enhancing its spatial coherence. A functional metasurface above the DBR layer precisely controls the TE wave's deflection angle. It maintains a low aspect ratio while enabling efficient, large-angle deflection. The simulation results demonstrate that this device provides an effective solution for generating highly spatially coherent directional LP light, with broad potential applications in fields such as polarized light imaging and advanced 3D micro-LED display systems.
Reconstruction of Z-pinch emission spectra in the wavelength range of less than 10 Å using a crystal X-ray spectrograph
Authors: Skobliakov A. V. , Kolesnikov D. S. , Kantsyrev A. V. , Golubev A. A. , Gritsuk A. N. , Volkov G. S. , Grabovskii E. V.
Published: July 2024

This work is devoted to the reconstruction of Z-pinch plasma emission spectra in the wavelength range of less than 10 Å recorded by using a crystal x-ray spectrograph at the Angara 5-1 mega-ampere facility. The spectrograph JA-1 used in experiments has a cylindrical mica crystal with dimensions of 50 × 40 mm2 and radius of curvature of 100 mm. Registration of spectra is performed on the photographic film UF-4 with dimensions of 30 × 10 mm2. To reconstruct the spectra, the previously developed method based on iterative approximation of a true spectrum shape while minimizing a residual between experimental and calculated spectrograms is used. The calculated spectrogram was obtained taking into account the instrumental function of the spectrograph. To define the instrumental function a virtual Monte-Carlo model in the Geant4 toolkit has been developed. This model takes into account the interaction of radiation with the mica crystal using dynamical theory of diffraction. A true spectrum of Z-pinch plasma radiation is reconstructed for a 16 mm high load made of two nested cylindrical wire liners. External liner with a diameter of 12 mm has 40 Al wires with a diameter of 18 μm. The internal liner with a diameter of 5 mm has 4 W wires with a diameter of 6 μm. The W wires have a sputtered layer of Re that is 0.5 μm thick.
Swift Au+9 ion irradiation-induced defects and alloy complexity effect on the mechanical hardness of NiCoCrFePd HEA and NiCoCrFe MEA
Authors: Hussain Abid , Khan S. A. , Sharma Sandeep K. , Sharma Saurabh K. , Singh Chetan , Rastogi Abhishek , Kulriya P. K.
Published: July 2024

The outstanding radiation damage stability of an NiCoCrFePd high entropy alloy (HEA) as compared to conventional alloys poses the question for the mechanism of an ion–matter interaction. The positron annihilation lifetime spectroscopic and TEM (transmission electron microscopic) measurements are implemented to trace different kinds of defects produced by 120 MeV Au+9 ion irradiation and their evolution as a function of ion fluence. The variation of lifetimes and corresponding intensities with the ion fluence indicates the formation of dislocation-type defects at a lower ion fluence and vacancy clusters at a higher ion fluence caused by coalescence or agglomeration of dislocation defects. Formation of different types of defects in turn modulates the strain development inside the crystal. Additionally, the HR-TEM investigation of NiCoCrFePd HEA also exhibits the formation of dislocation and vacancy clusters with the average size of vacancy clusters increases from ∼2.9 ± 0.1 to ∼3.8 ± 0.1 nm with the increases in the ion fluence. Surprisingly, the average defect cluster size in NiCoCrFePd HEA is suppressed compared to NiCoCrFe MEA, thereby showing the enhanced radiation stability on Pd incorporation due to the high defect recombination caused by reduced thermal conductivity and high lattice distortion. Nano-indentation measurement shows that the radiation hardening behavior of the NiCoCrFePd HEA responded slowly owing to its damage suppression property as compared to the NiCoCrFe MEA. Additionally, softening behavior also appeared at an early fluence in NiCoCrFe MEA compared to the NiCoCrFePd HEA signifying its excellent resistance to defect accumulation.
Acoustic phonon excitation in gold probed by time-resolved photoemission electron microscopy
Authors: Jiang Pengzuo , Zhang Linfeng , Zheng Wei , Wang Yang , Liu Yu , Xiao Jingying , Li Yaolong , Medvedev Nikita , Ischenko Anatoly , Kang Zexin , Liu Yunquan , Li Zheng , Wu Chengyin
Published: July 2024

Electron–phonon coupling is an important energy transfer mechanism in solids after ultrafast laser excitation. In this study, we present an extreme ultraviolet (EUV) and infrared (IR) pump-probe photoemission experiment to investigate the electron–phonon coupling in nonequilibrium gold. The energy of IR-laser-emitted photoelectrons is shifted due to the EUV photoemission and oscillates with a ∼4THz frequency. Such oscillation is considered as the effective excitation of the longitudinal acoustic phonon mode in gold through the spectral-dependent electron–phonon coupling. Our study showcases the capability of time-resolved photoemission electron microscopy to monitor the non-equilibrium lattice vibrations with ultrahigh spatial and temporal resolution.
Thermal detector based on a suspended polyimide membrane for infrared radiation applications
Authors: Bourgault D. , Paul G. , Latargez C. , Moiroux G. , Jegouso D. , Felix C. , Guttin C. , Garden J.-L.
Published: July 2024

This Letter details a pioneering study on the design and nanofabrication process of a thermoelectric infrared radiation detector using a suspended polyimide membrane. The research includes a comprehensive analysis of thermoelectric doped Bi2Te3 thin films, comparing their expected performance regarding noise and specific detectivity with other infrared detectors, particularly those in the silicon sector. Experimental results and calculations shed light on responsivity and time constants. In the absence of absorption layers, specific detectivity values for visible and near infrared radiation are measured at 9.2 × 107 and 2.9 × 107cm Hz/W, respectively, with a time constant nearing 20 ms. Calculations show that introducing an optimized absorption layer with ε = 1 significantly improves specific detectivity, reaching 9.0 × 108cm Hz/W. Subsequent calculations also show that further enhancement can be obtained by etching the polyimide membrane to a 1-micron thickness, resulting in an exceptional specific detectivity value of 8.4 × 109cm Hz/W, placing it among the best in the current state-of-the-art.
Silicon-based microscale-oscillating heat pipes for high power and high heat flux operation
Authors: Qian Qian , Zhang Xin , Tian Shurong , Yao Bojing , Weibel Justin A. , Pan Liang
Published: July 2024

Microscale-oscillating heat pipes (micro-OHPs) have recently drawn interest for electronic cooling applications due to their compact size and passive operating mechanism. The occurrence of dryout in OHPs, however, at which the working liquid no longer wets the evaporator, limits the maximum operating cooling power, preventing their integration for direct cooling of high heat flux semiconductor chips. Here, we report on high power and high flux operation of silicon-based OHPs by using microchannels with hydraulic diameters of ∼200 μm. Particularly, a micro-OHP with 100 μm channel height is shown to effectively operate at 210 W using a dielectric working fluid, corresponding to an unprecedented cooling power density of 145 W/cm2, without dryout. A distinctive oscillating mode with highly periodic bulk circulations occurs at high heating power and can provide efficient heat dissipation. The flow speed of the liquid under this bulk circulation mode can be as high as 10 m/s. The empirical relationships between the heat transfer rate, oscillating frequency, and device temperatures are studied.
Research on fault line selection method based on steady state variables
Authors: Wang Sha , Liu Changsheng , Wei Shengkai
Published: July 2024

When a single-phase ground fault occurs, the transient zero sequence current will significantly increase. So, it is possible to detect whether a single-phase grounding fault has occurred in the transmission line by calculating and comparing the amplitude of transient zero sequence current. Only when the amplitude of the zero sequence voltage under the steady-state power frequency is greater than the preset threshold can the line selection device be effectively and reliably started. The instantaneous value protection device can also be used to start first, and then, the steady-state amplitude of the power frequency can be compared as the verification object.
Turbulent structure and circulation inside different planar contractions
Authors: Alhareth Abdullah A. , Mugundhan Vivek , Langley Kenneth R. , Thoroddsen Sigurdur T.
Published: July 2024

We study the turbulent circulation and coherent vortical structures for flow through three separate two-dimensional planar 4:1 contractions, where the turbulence is subjected to different rates of mean strain. We use four high-speed video cameras for Lagrangian particle tracking velocimetry, to measure time-resolved velocity fields in volumes inside the contractions. We identify the coherent vortical structures and quantify their alignment with the mean strain. The intermediate strain contraction shows the strongest alignment. We also compute circulations around square loops in three perpendicular planes, to form a “circulation vector,” whose instantaneous alignment mirrors that of the coherent structures, with strong inhomogeneities between circulation components at the exit of the contractions. The circulation probability density functions show extended exponential tails for the smallest loops, with more Gaussian shapes in the inertial range.
Comparative analysis of mechanical wall shear stress and hemodynamics to study the influence of asymmetry in abdominal aortic aneurysm and descending thoracic aortic aneurysm
Authors: Rehman M. Abaid Ur , Ekici Özgür
Published: July 2024

An aneurysm's rupture is commonly associated with its maximum diameter, yet biomechanical studies emphasize the significant influence of mechanical wall shear stress (WSS) in this process. This study focuses on two models of aortic aneurysms: abdominal aortic aneurysm and descending thoracic aortic aneurysm. Five cases, comprising two for model 1 and three for model 2, are examined to explore both axisymmetric and asymmetric shapes, as patient geometry may manifest as either fusiform (axisymmetric) or saccular (asymmetric), while maintaining a consistent aneurysm diameter and adjusting the bulge shape factor to induce asymmetry. Hemodynamic factors, including WSS and wall shear stress gradient, are computed to evaluate thrombus formation and rupture risk within the aneurysms. Our results indicate the presence of recirculation zones in both the medial and transverse planes, generating vortices within the aneurysm. These vortices are more prominent in asymmetric cases compared to axisymmetric cases, leading to increased blood residence time within the aneurysm and a higher likelihood of thrombus formation. Thrombus formation can further impede blood flow, heightening the risk of embolism or ischemic events. Rupture occurs when the WSS surpasses tissue strength; thus, if the tissue strength of all aneurysms is same, our findings suggest that rupture risk varies according to asymmetry. In the transverse direction, our results demonstrate that in model 1, case 1 exhibits uniform WSS on both sides, while in case 2, WSS is higher at the posterior sides of the aneurysm sac. Conversely, in model 2, WSS is higher at the anterior side of the aneurysm. In the medial direction of the aneurysm, WSS is highest for case 5, followed by case 3, case 4, case 2, and case 1, respectively, indicating elevated WSS when the anterior bulge dominates over the posterior bulge for each model. Overall, a higher rupture risk is observed in model 2 compared to model 1 due to increased mechanical stresses.
Magnetic and magneto-transport properties of non-collinear antiferromagnetic Mn3Ge epitaxial films
Authors: Takeuchi Yutaro , Sepehri-Amin Hossein , Sugimoto Satoshi , Hiroto Takanobu , Kasai Shinya
Published: July 2024

Antiferromagnetic Mn3X (X = Sn, Ge, Ga, and Pt) possessing non-collinear spin structures with Kagome lattices have attracted increasing interest because of their unique properties, such as significant anomalous Hall and magneto-optical Kerr effects. Recent advances in spintronic devices that use non-collinear antiferromagnets have inspired research into various materials for exploiting their potential. In this study, we investigated the magnetic and magneto-transport properties of 11̄00-oriented epitaxial and polycrystalline Mn3Ge films deposited by magnetron sputtering. Anomalous Hall conductivity monotonically decreases with temperature in an epitaxial Mn3Ge film, whereas the polycrystalline sample demonstrates a different trend. Furthermore, we obtained a large in-Kagome-plane uniaxial magnetic anisotropy of epitaxial Mn3Ge above ambient temperature, thereby leading to higher thermal stability and robustness against the external field. Our results indicate the potential of Mn3Ge for future functional, high-speed, and high-density spintronics devices using antiferromagnets.
Surface charge-dependent slip length modulates electroosmotic mixing in a wavy micromixer
Authors: Khatibi Mahdi , Mehta Sumit Kumar , Ashrafizadeh Seyed Nezameddin , Mondal Pranab Kumar
Published: July 2024

This study explores electroosmotic mixing in microfluidic channel with predefined surface topology, mainly focusing the effect of surface charge-dependent slip length on the underlying mixing dynamics. Our analysis addresses the need for precise control of flow and mixing of the participating fluids at microscale, crucial for medical and biomedical applications. In the present work, we consider a wavy microchannel with non-uniform surface charge to explore the electroosmotic mixing behavior. To this end, adopting a finite-element approach, we numerically solve the Laplace, Poisson–Boltzmann, convection–diffusion, and the Navier–Stokes equations in a steady-state. The model is validated by comparing the results with the available theoretical and experimental data. Through numerical simulations, the study analyzes electroosmotic flow patterns in microchannels, highlighting the impact of surface charge-dependent slip lengths on mixing efficiency. For example, at a diffusive Peclet number of 200, mixing efficiency drops from 95.5% to 91.5% when considering surface charge-dependent slip length. It is established that the fluid rheology, characterized by Carreau number and flow behavior index, non-trivially influences flow field modulation and mixing efficiency. Increased Carreau numbers enhance flow velocity, affecting overall mixing of the constituent fluids in the chosen fluidic pathway. For instance, by increasing the Carreau number from 0.01 to 1.0, a discernible trend emerges with higher flow line density and accelerated velocity within the microchannel. The study also examines the effect of diffusive Peclet numbers on the mixing efficiency, particularly in the convective regime of underlying transport. These insights offer practical guidance for designing microfluidic systems intended for enhanced mixing capabilities. Additionally, the study explores the likelihood of particle aggregation under shear forces, vital in biological non-Newtonian fluids, with implications for drug delivery, diagnostics, and biomedical technologies.
The creeping movement of a soft colloidal particle normal to a planar interface
Authors: Ragab Kareem E. , Faltas M. S.
Published: July 2024

A methodological blend of analytical and numerical strategies employing collocation techniques is presented to investigate the task of describing the Stokes flow generated by a soft particle (composite sphere) moving perpendicularly to a planar interface of infinite extent, separating two semi-infinite, immiscible viscous fluid domains. The particle consists of a solid core enclosed by a porous membrane allowing fluid passage. The movement of the soft nanoparticle has been examined through a continuum mathematical model. This model incorporates the Stokes and Brinkman equations, accounting for the hydrodynamic fields both outside and within the porous membrane layer, respectively. The motion is investigated under conditions characterized by low Reynolds and capillary numbers, where the interface experiences negligible deformation. The solution combines cylindrical and spherical fundamental solutions via superposition. Initially, the boundary conditions at the fluid–fluid interface are satisfied utilizing Fourier–Bessel transforms, subsequently addressing the conditions at the soft particle's surface through a collocation method. The normalized drag force exerted on the particle is accurately calculated, exhibiting robust convergence across various geometric and physical parameters. These findings are effectively visualized via graphs and tables. We juxtapose our drag force coefficient results with established literature data, particularly focusing on the extreme cases. The findings highlight the substantial impact of the interface on the drag force coefficient. Across the full range of viscosity ratios, the normalized drag force decreases as the relative thickness of the porous layer increases. These results enhance the understanding of practical systems and industrial processes such as sedimentation, flotation, electrophoresis, and agglomeration.
On weak influence of aluminum powder size on its post-detonation reaction in different time scales
Authors: Zhang Dongjiang , Yi Zhicong , Gan Yundan , Liu Qijun , Liu Fusheng , Li Xinghan
Published: July 2024

The outstanding performance of aluminized explosives is attributed to the substantial energy released through aluminum (Al) reactions during post-detonation flow. However, the influences of Al powder size on the explosion power of aluminized explosives sometimes vary significantly across different time scales, which may suggest potential differences in Al reaction processes. To investigate the size-dependent reaction behavior of Al powders at different time scales, a novel experimental apparatus was employed to measure the velocity of a rod propelled by the detonation products of RDX/Al explosives (with Al powder sizes of 1.9 µm or 47.1 µm)1 at ∼1 ms, and the results were compared to those obtained from previous tube tests at around 30 µs. The experimental findings reveal that the impact of Al powder size on the metal-driven capability of aluminized explosives is not substantial at either 1 ms or 30 µs. Given the inadequacy of the phenomenological equation of state for studying the Al reaction due to its inability to ensure the uniqueness of the reaction process, we investigated the tburn∝dAln law using the Gurney energy method, where dAl and tburn denote the powder size and combustion time of Al powders, respectively. The values of n (0.031 and 0.038) were examined for the first time in post-detonation flow, which are significantly smaller than those observed in quasi-static flow. These results substantiate that the weak powder size effect on Al reaction is likely a prevalent phenomenon for micron-sized Al powders in post-detonation flow, attributable to the high pressure and high velocity characteristic of such flows.
Mechanistic insights into phosphoactivation of SLAC1 in guard cell signaling
Authors: Qin Li , Deng Ya-nan , Zhang Xiang-yun , Tang Ling-hui , Zhang Chun-rui , Xu Shi-min , Wang Ke , Wang Mei-hua , Zhang Xian-hui , Su Min , Xie Qi , Hendrickson Wayne A. , Chen Yu-hang
Published: July 2024

Stomata in leaves regulate gas (carbon dioxide and water vapor) exchange and water transpiration between plants and the atmosphere. SLow Anion Channel 1 (SLAC1) mediates anion efflux from guard cells and plays a crucial role in controlling stomatal aperture. It serves as a central hub for multiple signaling pathways in response to environmental stimuli, with its activity regulated through phosphorylation via various plant protein kinases. However, the molecular mechanism underlying SLAC1 phosphoactivation has remained elusive. Through a combination of protein sequence analyses, AlphaFold-based modeling and electrophysiological studies, we unveiled that the highly conserved motifs on the N- and C-terminal segments of SLAC1 form a cytosolic regulatory domain (CRD) that interacts with the transmembrane domain(TMD), thereby maintaining the channel in an autoinhibited state. Mutations in these conserved motifs destabilize the CRD, releasing autoinhibition in SLAC1 and enabling its transition into an activated state. Our further studies demonstrated that SLAC1 activation undergoes an autoinhibition-release process and subsequent structural changes in the pore helices. These findings provide mechanistic insights into the activation mechanism of SLAC1 and shed light on understanding how SLAC1 controls stomatal closure in response to environmental stimuli.
Organic nanoparticles with tunable size and rigidity by hyperbranching and cross-linking using microemulsion ATRP
Authors: Yin Rongguan , Tarnsangpradit Jirameth , Gul Akhtar , Jeong Jaepil , Hu Xiaolei , Zhao Yuqi , Wu Hanshu , Li Qiqi , Fytas George , Karim Alamgir , Bockstaller Michael R. , Matyjaszewski Krzysztof
Published: July 2024

Unlike inorganic nanoparticles, organic nanoparticles (oNPs) offer the advantage of “interior tailorability,” thereby enabling the controlled variation of physicochemical characteristics and functionalities, for example, by incorporation of diverse functional small molecules. In this study, a unique inimer-based microemulsion approach is presented to realize oNPs with enhanced control of chemical and mechanical properties by deliberate variation of the degree of hyperbranching or cross-linking. The use of anionic cosurfactants led to oNPs with superior uniformity. Benefitting from the high initiator concentration from inimer and preserved chain-end functionality during atom transfer radical polymerization (ATRP), the capability of oNPs as a multifunctional macroinitiator for the subsequent surface-initiated ATRP was demonstrated. This facilitated the synthesis of densely tethered poly(methyl methacrylate) brush oNPs. Detailed analysis revealed that exceptionally high grafting densities (~1 nm
−2
) were attributable to multilayer surface grafting from oNPs due to the hyperbranched macromolecular architecture. The ability to control functional attributes along with elastic properties renders this “bottom-up” synthetic strategy of macroinitiator-type oNPs a unique platform for realizing functional materials with a broad spectrum of applications.
Electronic Correlation and Pseudogap-Like Behavior of High-Temperature Superconductor La3Ni2O7
Authors: Li 李 Yidian 义典 , Du 杜 Xian 宪 , Cao 曹 Yantao 延涛 , Pei 裴 Cuiying 翠颖 , Zhang 张 Mingxin 明鑫 , Zhao 赵 Wenxuan 文轩 , Zhai 翟 Kaiyi 恺熠 , Xu 许 Runzhe 润哲 , Liu 柳 Zhongkai 仲楷 , Li 李 Zhiwei 志伟 , Zhao 赵 Jinkui 金奎 , Li 李 Gang 刚 , Qi 齐 Yanpeng 彦鹏 , Guo 郭 Hanjie 汉杰 , Chen 陈 Yulin 宇林 , Yang 杨 Lexian 乐仙
Published: July 2024

High-temperature superconductivity (HTSC) remains one of the most challenging and fascinating mysteries in condensed matter physics. Recently, superconductivity with transition temperature exceeding liquid-nitrogen temperature is discovered in La3Ni2O7 at high pressure, which provides a new platform to explore the unconventional HTSC. In this work, using high-resolution angle-resolved photoemission spectroscopy and ab initio calculation, we systematically investigate the electronic structures of La3Ni2O7 at ambient pressure. Our experiments are in nice agreement with ab initio calculations after considering an orbital-dependent band renormalization effect. The strong electron correlation effect pushes a flat band of d

z
2
orbital component below the Fermi level (E
F), which is predicted to locate right at E
F under high pressure. Moreover, the d

x
2–y
2
band shows pseudogap-like behavior with suppressed spectral weight and diminished quasiparticle peak near E
F. Our findings provide important insights into the electronic structure of La3Ni2O7, which will shed light on understanding of the unconventional superconductivity in nickelates.
Oxygen-mediated defect evolution and interface analysis of MoOx/n-Si devices
Authors: Kumar Abhishek , Tomer Shweta , Vandana  , Fix Thomas , Dutta Mrinal , Srivastava Sanjay Kumar , Pathi Prathap
Published: July 2024

The performance of MoO
x
based devices is highly influenced by the presence of oxygen vacancies and the trap density at the oxide-semiconductor interface. This paper presents a detailed investigation of the surface states present at the MoO
x
/c-Si interface through capacitance and conductance methods. Thin films of MoO
x
were deposited on n-Si using DC reactive sputtering of Mo under varying oxygen flow rates and studied the modulation of metal-insulator-semiconductor (MIS) device parameters using appropriate analysis methods. The capacitance-voltage (CV) analysis reveals the formation of nearly dielectric films at an intermediate oxygen flow rate of 15 sccm, exhibiting a dielectric constant of 24 and negative fixed charges of approximately 1.81 × 1012 cm−2. The work function evaluated from the Kelvin probe measurements was found to be a maximum of 5.08 eV for the films deposited at an intermediate oxygen flow rate of 15 sccm. Furthermore, admittance analysis was performed on all the films to determine the loss mechanism in different regions, ranging from inversion to accumulation. Parallel conductance for different bias conditions was studied and observed the domination of oxide traps at higher oxygen flow rates (>20 sccm). Investigations of deep level defects were performed using deep level transient spectroscopy (DLTS) in the temperature range of 100 K–475 K, along with the C-V measurements. A transition in C-V behavior is observed below room temperature, implying that the minority carrier response time is controlled by generation-recombination at low temperatures and by diffusion at high temperatures. X-ray photoelectron spectroscopy (XPS) measurements showed that the films are sub-stoichiometric with the dominant oxidation state of Mo+6. The results are discussed and presented in detail.
Generalized ghost pilgrim dark energy model in Non-Riemannian geometry
Authors: Sharif M , Ajmal Madiha
Published: July 2024

In this paper, we analyze cosmic evolution and current expansion using the generalized ghost pilgrim dark energy model for the flat Friedmann-Robertson-Walker universe in

f
(
Q
)

gravity, where

Q

represents the non-metricity. For this objective, we examine interacting forms of dark energy model and reconstruct

f
(
Q
)

gravity in terms of red-shift parameter. We establish various standard cosmological parameters including the equation of state parameter, the squared speed of sound,

ω

D

−

ω

D

′

and r − s-planes to examine the impact of this dark energy model. The analysis reveals that all the reconstructed models exhibit an increasing or decreasing trend in the pilgrim dark energy parameter. The equation of state parameter depicts the phantom era, while the squared speed of sound reveals a stable generalized ghost pilgrim dark energy model for the entire cosmic evolutionary paradigm. Finally, we study the cosmography of the

ω

D

−

ω

D

′

and r − s planes that correspond to the freezing region and Chaplygin gas model, respectively. We conclude that all the outcomes are consistent with the pilgrim dark energy phenomenon.
Revealing the microstructures of metal halide perovskite thin films via advanced transmission electron microscopy
Authors: Xian 冼 Yeming 业铭 , Wang 王 Xiaoming 晓明 , Yan 鄢 Yanfa 炎发
Published: July 2024

Metal halide perovskites (MHPs) are excellent semiconductors that have led to breakthroughs in applications in thin-film solar cells, detectors, and light-emitting diodes due to their remarkable optoelectronic properties and defect tolerance. However, the performance and stability of MHP-based devices are significantly influenced by their microstructures including the formation of defects, composition fluctuations, structural inhomogeneity, etc. Transmission electron microscopy (TEM) is a powerful tool for direct observation of microstructure at the atomic-scale resolution and has been used to correlate the microstructure and performance of MHP-based devices. In this review, we highlight the application of TEM techniques in revealing the microstructures of MHP thin films at the atomic scale. The results provide critical understanding of the performance of MHP devices and guide the design of strategies for improving the performance and stability of MHP devices.
Current sensor unanticipated fault detection and compensation of 14.5-meter optical/infrared telescope drive system based on algebraic transformations
Authors: Deng Zhuangzhuang , Yang Shihai , Li Yun , Xu Lingzhe , Pan Cong , Jiang Canyi , Guo Yanpeng
Published: July 2024

This paper discusses an unanticipated fault detection,
isolation, and compensation (FDIC) strategy for the arc splicing
permanent magnet synchronous motor (PMSM) operating under a
promising 14.5-meter optical/infrared telescope drive system,
specifically focusing on current sensors. The application is based
on algebraic transformations that allow not only failure detection
but also location and isolation. Besides, detection is performed
merely by means of the measured current sensors and does not require
additional knowledge or estimators; isolation utilizes information
provided by detection to locate where the faults originated and
release isolation signals; and compensation is carried out through
the remaining currents that are not affected by the faults. It is
noted from the results that the performance of FDIC in faulty mode
is very acceptable and uncompromising in terms of fault detection,
current symmetry, speed tracking, load torque and robustness
remedial measures. Therefore, the proposed method can effectively
ensure the stable operation of the drive system in the presence of
faults.
Calculation of efficiency and resolution of a hexagonal NaI(Tl) detector as a function of source position
Authors: Hamzawy A. , Badawi M.S. , Ruskov I.N. , Grozdanov D.N. , Badawi M.I. , Thabet A.A. , Kopatch Yu.N. , Fedorov N.A. , Salem B.A. , collaboration TANGRA
Published: July 2024

Most gamma-ray scintillation detectors currently in use are made from inorganic materials that have a relatively high electron density. Quite often they are used to build multidetector systems that provide high scintillation light output. The performance of a gamma radiation detector (its detection efficiency) depends on the shape and size of the crystal, as well as on the source-to-detector geometry used. The NaI(Tl) gamma detector exhibits moderate energy resolution but relatively high gamma-ray detection efficiency and fast time response. In this work, the efficiency and resolution of a scintillation hexagonal detector are studied to optimize its response function. This type and size of scintillator were selected to construct a budget-friendly, reconfigurable, easy-to-maintain multidetector system for registering gamma-rays following fission, capture, and inelastic neutron scattering reactions, with reasonably good energy and time resolutions The research results made it possible to establish a geometric solid angle that increases the efficiency of recording gamma-ray radiation of the hexagonal NaI(Tl) scintillation probe under study.
A review of bioinspired dry adhesives: from achieving strong adhesion to realizing switchable adhesion
Authors: Zhao Jinsheng , Xia Neng , Zhang Li
Published: July 2024

In the early twenty-first century, extensive research has been conducted on geckos’ ability to climb vertical walls with the advancement of microscopy technology. Unprecedented studies and developments have focused on the adhesion mechanism, structural design, preparation methods, and applications of bioinspired dry adhesives. Notably, strong adhesion that adheres to both the principles of contact splitting and stress uniform distribution has been discovered and proposed. The increasing popularity of flexible electronic skins, soft crawling robots, and smart assembly systems has made switchable adhesion properties essential for smart adhesives. These adhesives are designed to be programmable and switchable in response to external stimuli such as magnetic fields, thermal changes, electrical signals, light exposure as well as mechanical processes. This paper provides a comprehensive review of the development history of bioinspired dry adhesives from achieving strong adhesion to realizing switchable adhesion.
Poisson electrodynamics with charged matter fields
Authors: Sharapov Alexey A
Published: July 2024

Poisson electrodynamics is the low-energy limit of a rank-one noncommutative gauge theory. It admits a closed formulation in terms of a Poisson structure on the space-time manifold and reproduces ordinary classical electrodynamics in the commutative limit. In this paper, we address and solve the problem of minimal coupling to charged matter fields with a proper commutative limit. Our construction relies essentially on the geometry of symplectic groupoids and works for all integrable Poisson manifolds. An additional advantage of our approach is that the corresponding Lagrangians can be defined on an arbitrary metric background.
Identification of temperature and diffusion effects during helium swelling of the surface layer of a TiTaNbV alloy
Authors: Giniyatova Sholpan G , Kadyrzhanov Kayrat K , Shlimas Dmitriy I , Borgekov Daryn B , Kozlovskiy Artem L , Uglov Vladimir V
Published: July 2024

The article presents the comprehensive analysis results of the connection between structural changes caused by the effects of deformation swelling and softening effects during high-dose irradiation with He2+ ions, alongside determines the kinetics of changes in structural and strength parameters contingent upon irradiation conditions (in the case of irradiation temperature variations). The interest in such studies is due to the need to study the influence of temperature factors on the diffusion mechanisms of implanted He2+ into the damaged layer of a high-entropy TiTaNbV alloy in the case of high-dose irradiation. At the same time, the study of such mechanisms makes it possible to determine not only the radiation resistance of TiTaNbV alloys, but also to expand the general understanding of the influence of the structural features of high-entropy alloys associated with deformation distortion of the crystal structure, which prevents diffusion and migration mechanisms of defect propagation in the damaged layer. During determination of changes in strength properties depending on irradiation conditions, it was found that irradiation temperature growth leads to both a rise in the degree of softening under high-dose irradiation and an increase in the thickness of the softened layer under high-dose irradiation. These changes indicate that at high temperatures, the diffusion of implanted ions is not restrained by structural distortions, which results in their migration to a greater depth exceeding the ion travel depth, which should be considered when designing the use of these alloys in the case of their operation in extreme conditions.