bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of Smagorinsky LES turbulence model in FluidX3D LBM: In-place vs central difference
Authors: Plekhanov Mikhail , Mullyadzhanov Rustam
Published: October 2024

Lattice Boltzmann method (LBM) has been rapidly developing as a CFD approach throughout the last three decades. The rise of new computational architectures like GPU in the last decade pawed the way to emergence of high-performance CFD software based on this method. The most outstanding of such is FluidX3D, utilizing locality of algorithm operations in connection with massive parallelism of GPU. High performance and memory efficiency of this software make it a promising idea to apply FluidX3D to challenging CFD problems, like turbulence simulation. In this work an effort is put into validation of Smagorinsky LES turbulence model implemented in this software. In addition, direct central difference implementation of this model is added to verify existing approach. The validation is done on the turbulent plane channel flow at Reτ = 180. Reasonable agreement between two LES model results was obtained. The convergence of LES profiles to DNS profiles with sufficient resolution proves correctness of implemented model.
Combustion	Of Methane With Microdroplets	Of Water In	A	Weak Electric Field
Authors: Tupikin Andrey , Dulin Vladimir , Sharaborin Dmitry
Published: October 2024

The effect of a weak electric field on the flame of a Bunsen burner, including the case of an aerosol consisting of water microdroplets in an air-methane mixture has been studied in detail. The propagation velocities of the laminar flame have been determined. If the stabilization area (burner edge) and the flame tip are excluded from consideration, the average propagation velocity of a laminar flame in the absence of an electric field is constant. For a stoichiometric mixture of methane with air and aerosol combustion, it is equal to Su≈0.35 and 0.3 m/s, respectively. When an electric field is applied, there is a common trend for cases of combustion of methane and a gas-droplet mixture, i.e., maintaining the flame front propagation velocity from the anode side and increasing by about 8-10% from the cathode side.
Spinal anesthesia for endoscopic submucosal dissection of large rectosigmoid lesions: Feasibility study
Authors: Bonura Giuliano Francesco , Biancheri Paolo , Rainer Joachim , Soriani Paola , Rodriguez de Santiago Enrique , Parrella Arianna , Campioli Alice , Guerra Emmanuele , Gualdi Eugenia , Pignatti Alessandro , Manno Mauro
Published: October 2024

Background and study aims Colorectal endoscopic submucosal
dissection (ESD) is often challenging and time-consuming. Prolonged sedation and general
anesthesia are associated with a relevant risk of anesthesia-related adverse events (ARAEs),
especially in elderly and frail patients. Spinal anesthesia (SA), a simple technique providing
analgesia and motor block without systemic drug administration, has never been described in
gastrointestinal endoscopy. We assessed the feasibility of SA in colorectal lesion ESD.

Patients and methods We retrospectively collected data on all consecutive patients who underwent ESD for colorectal laterally spreading tumors (LSTs) under SA in our center during the last 3 years. We evaluated the rates of technical success, i.e. ESD completion under SA without need of conversion to deep sedation or general anesthesia, and ARAEs after SA.

Results ESD under SA was performed on 20 rectosigmoid LSTs ≥ 35 mm. Technical success was achieved in 95.0% of cases (19/20), while one patient (5.0%) required conversion to deep sedation. Two patients (10.0%) experienced acute urinary retention that was successfully treated with temporary catheterization.

Conclusions Our initial experience suggests that SA for ESD of large rectosigmoid LSTs is feasible, and it may prove to be a valuable option, especially for elderly and frail patients.
Neuroleptic Malignant Syndrome in a 10-Month-Old Ex-Preterm Infant with Delirium
Authors: Akuamoah-Boateng Gloria , Buttafuoco Kayla A. , Sutton Courtney C. , Hackett Brian P.
Published: October 2024

In recent times, atypical antipsychotics are increasingly being used in the neonatal intensive care unit (NICU) for the management of neonatal delirium. As the recognition of delirium in NICU infants increases, caution should be exercised with use of antipsychotics for management, given associated adverse effects. Neuroleptic malignant syndrome (NMS) is a rare adverse drug reaction associated with exposure to antipsychotics and other antidopaminergic medications. Most reported cases of NMS in pediatric patients have been in older children on antipsychotic medications. We present a case of a 10-month-old former preterm infant who developed clinical signs suggestive of NMS after exposure to olanzapine for treatment of delirium. Our case report details the clinical course of this infant, delves into the condition, and outlines some useful lessons for the clinician in the identification and management of this rare but life-threatening adverse effect.

Key Points
A Convenient Synthesis of CHF2O-Containing Pyrrolidines and Related Compounds — Prospective Building Blocks for Drug Discovery
Authors: Levchenko Kostiantyn , Virstiuk Ivan , Menshykova Daria , Pokhodylo Nazariy
Published: October 2024

Fluorine-containing organic molecules, including CHF2O derivatives, are among the most sought-after in medicinal chemistry. In the current work, a mini-library of 21 compounds with a CHF2O motif incorporated with azetidine, pyrrolidine (proline), piperidine, 2-azabicyclo[2.2.1]heptane, and 8-azabicyclo[3.2.1]octane cores was synthesized. A multigram scale (10–30 g) procedure for synthesizing the title compounds from commercially available amino alcohols was studied.
Striking gold: study explores light resonance with layered metallic arrays
Authors: Ikenson Ben
Published: October 2024

Overcoming the limitations of single gold nanostructures to expand color gamut
Plasma discharge experiments of a Faraday shieldless driver for high-power and long-pulse radio frequency ion source for NBI application
Authors: Liu Bo , Peng Xufeng , Gu Yuming , Yang Yuwen , Li Yufan , Jiang Caichao , Liu Zhimin , Xie Yahong , Wei Jianglong
Published: October 2024

Due to the high stability and less maintenance, the radio frequency (RF) driven ion source is preferred for the neutral beam injection (NBI) system. In a popular design of the RF ion source for NBI application, a Faraday shield (FS) is installed inside the RF plasma driver to protect the discharge tube. However, the FS also brings some drawbacks, such as lowering the RF power transfer and increasing the processing difficulty. A prototype of the RF plasma driver without FS and with mature manufacturing technology has been developed by using a water-cooled discharge tube. After basic testing, this prototype was further tested under the RF plasma discharge experiments in views of high power, long pulse, and long term. The reliability and its plasma characteristics were the focus of these experiments, also for the hidden issues. The results show that the prototype could generate stable and high-density plasma without any damage or sputtering mark. An RF plasma discharge of 50 kW and 20 s has been achieved. The expected frequency tuning was equally effective on the prototype. Moreover, compared to the RF plasma driver with FS, the prototype could produce higher electron density in the extraction region under the same RF power. Of course, some of the shortcomings of the prototype have also been exposed in the experiments and will be improved in subsequent experiments.
Precision multi-mode microwave spectroscopy of paramagnetic and rare-earth ion spin defects in single crystal calcium tungstate
Authors: Hartman Elrina , Tobar Michael E. , McAllister Ben T. , Bourhill Jeremy , Goryachev Maxim
Published: October 2024

We present experimental observations of dilute ion spin ensemble defects in a low-loss single crystal cylindrical sample of CaWO4 cooled to 30 mK in temperature. Crystal field perturbations were elucidated by constructing a dielectrically loaded microwave cavity resonator from the crystal. The resonator exhibited numerous whispering gallery modes with high Q-factors of up to 3×107, equivalent to a loss tangent of ∼3×10−8. The low loss allowed precision multi-mode spectroscopy of numerous high Q-factor photon–spin interactions. Measurements between 7 and 22 GHz revealed the presence of Gd3+, Fe3+, and another trace species, inferred to be rare-earth, at concentrations on the order of parts per billion. These findings motivate further exploration of prospective uses of this low-loss dielectric material for applications regarding precision and quantum metrology, as well as tests for beyond standard model physics.
Long ranged stress correlations in the hard sphere liquid
Authors: Grimm Niklas , von Bischopinck Martin , Zumbusch Andreas , Fuchs Matthias
Published: October 2024

The smooth emergence of shear elasticity is a hallmark of the liquid to glass transition. In a liquid, viscous stresses arise from local structural rearrangements. In the solid, Eshelby has shown that stresses around an inclusion decay as a power law r−D, where D is the dimension of the system. We study glass-forming hard sphere fluids by simulation and observe the emergence of the unscreened power-law Eshelby pattern in the stress correlations of the isotropic liquid state. By a detailed tensorial analysis, we show that the fluctuating force field, viz., the divergence of the stress field, relaxes to zero with time in all states, while the shear stress correlations develop spatial power-law structures inside regions that grow with longitudinal and transverse sound propagation. We observe the predicted exponents r−D and r−D−2. In Brownian systems, shear stresses relax diffusively within these regions, with the diffusion coefficient determined by the shear modulus and the friction coefficient.
Exploring atmospheric nucleation processes: Hydration and fluoroalcoholic complexation of pyruvic acid
Authors: Vázquez Andrea , Pinacho Pablo , Parra-Santamaría Maider , Basterretxea Francisco J. , Chin Wutharath , Cocinero Emilio J.
Published: October 2024

This study examines the intermolecular interactions between small molecules and solvents, with a particular focus on pyruvic acid (PA). PA plays a significant role in biochemistry, astrochemistry, and atmospheric chemistry, particularly in aerosol particle formation. Previous studies on PA have been expanded upon by exploring its hydration and complexation with 2,2,2-trifluoroethanol (TFE). The clusters were generated using a supersonic expansion and characterized by broadband Fourier transform microwave spectroscopy. The structures of the clusters were identified by comparing the experimental results with high-level quantum-chemical computations. Among the possible isomers for the hydrated complex, the Tc-(H2O)2 kinetic complex, where PA exhibits an internal hydrogen bond, was favored over the Tt-(H2O)2 form, predicted to be the most stable conformer. Transitions from both the A and E internal rotation substates were observed exclusively in the dihydrate. The complex with TFE did not exhibit splitting due to the internal rotation of the methyl top. This is attributed to the presence of electronegative fluorine groups in TFE, stabilizing the complex through additional CH⋯F interactions, thereby hindering the internal rotation motion of the methyl top.
Direct magnetoelectric coupling in Pr doping Bi6Ti3Fe2O18 relaxor ferroics
Authors: Zhao Penju , He Chunyan , Li Yang , Su Yating , Bai Yulong , Zhao Shifeng
Published: October 2024

Single-phase multiferroics are fractional and rarely meet at room temperature. Direct magnetoelectric coupling in relaxor ferroic phase was observed in Bi6−xPrxTi3Fe2O18 (x = 0.0, 0.3, 0.6, 0.9, and 1.2) films, where the chemical disorder doping-induced effective internal pressure played a key role. It is analytically formulated from the phase-structure shift, ferroelectric domain, and origin of the magnetic order. The strip magnetic domains are broken into a dotted domain structure following a quantitatively increase in lattice stress. A Monte Carlo simulation including stress energy items is used to unveil the hitherto unexplored coupling mechanism by tuning the symmetric exchange restriction of Fe3+–O–Fe3+. Moreover, the observation of coefficient 78.8 mV/cm·Oe at room temperature is intriguing for potential application.
Macroscopic perspective on phase transition behavior of natural single-crystal graphite under different pressure environments
Authors: Yin Xiaoshuang , Li Songyang , Wang Lijuan , Liu Peiyuan , Cheng Zhihai , Gou Huiyang , Yang Liuxiang
Published: October 2024

Comprehensive understanding of the direct transformation pathway from graphite to diamond under high temperature and high pressure has long been one of the fundamental goals in materials science. Despite considerable experimental and theoretical progress, current experimental studies have mainly focused on the local microstructural characterizations of recovered samples, which has certain limitations for high-temperature and high-pressure products, which often exhibit diversity. Here, we report on the pressure-induced phase transition behavior of natural single-crystal graphite under three distinct pressure-transmitting media from a macroscopic perspective using in situ two-dimensional Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The surface evolution process of graphite before and after the phase transition is captured, revealing that pressure-induced surface textures can impede the continuity of the phase transition process across the entire single crystal. Our results provide a fresh perspective for studying the phase transition behavior of graphite and greatly deepen our understanding of this behavior, which will be helpful in guiding further high-temperature and high-pressure syntheses of carbon allotropes.
Rapid wavelength interval selection technology for multi-channel intensity-interrogation surface plasmon resonance imaging sensing
Authors: Liu Xiaorui , Huang Songfeng , Tai Jiali , Ni Hailong , Dai Xiaoqi , Wang Xueliang , Chen Jiajie , Ho Ho-Pui , Qiu Ping , Wang Yuye , Shao Yonghong
Published: October 2024

Intensity-interrogation surface plasmon resonance (I-SPR) provides the fastest imaging speed among various SPR techniques, including wavelength, phase, and angle-based detection. It also integrates easily with other devices and has substantial practical application potential. However, I-SPR's reliance on direct detection of reflected light intensity renders it sensitive to light source fluctuations and detector dark noise, and its dynamic range is relatively limited. To address these challenges, we have developed a multi-channel I-SPR sensing platform featuring rapid wavelength interval selection technology. This system optimizes the sensing wavelength according to the refractive indices of different samples, mitigating issues related to inconsistent SPR signals from various biomolecules. Our improved I-SPR technology enables high-throughput biomolecular detection with a refractive index range size of 2.035 × 10−2 for dynamic monitoring, reaching a leading role among the existing I-SPR technologies. This represents the widest linear dynamic range for I-SPR to date. Experimental results on protein binding kinetic constants KD are consistent with those obtained from commercially available instruments. We believe that this study is expected to accelerate the development of SPR technology toward broader biological applications.
Toxicological consequences of polystyrene microplastics on Cirrhinus mrigala: effects on growth, body composition, nutrient digestibility, haematology and histopathology
Authors: Rashid Eram , Hussain Syed Makhdoom , Ali Shafaqat , Al-Ghanim Khalid A. , Sarker Pallab K.
Published: October 2024

Context Microplastics (MPs), whether originating from primary or secondary means, have emerged as a significant global issue nowadays. Aims The current research was designed to assess the toxicological consequences of polystyrene MPs (PS-MPs) on the growth, digestibility, body composition, haematology and histopathology of Cirrhinus mrigala fingerlings. Methods In this study, six test diets with different MP concentrations were used, including a control group (0% MPs) and groups with 0.5, 1, 1.5, 2 and 2.5% MPs in sunflower meal-based diets. For a 90-day duration, 270 fingerlings (6.54 ± 0.02 g fish−1) were placed in triplicate groups in tanks, with each tank consisting of 15 fingerlings, feeding at a rate equivalent to 5% of their live wet bodyweight. Key results The findings revealed a negative correlation between MP concentration and fingerlings performance, encompassing growth, digestibility, body composition, histopathology and hematology. Conclusions The results indicate that 2.5% MPs inclusion in C. mrigala adversely affects growth, digestibility, body composition, histopathology and hematology. Implications This research highlights the harmful effects of PS-MPs on C. mrigala fingerlings, emphasising urgent global action to address and mitigate aquatic ecosystem threats.
Abortive infection of bat fibroblasts with SARS-CoV-2
Authors: Bisht Punam , Gallagher Michael D. , Barrasa M. Inmaculada , Boucau Julie , Harding Alfred , Déjosez Marion , Godoy-Parejo Carlos , Bisher Margaret E. , de Nola Giovanni , Lytton-Jean Abigail K. R. , Gehrke Lee , Zwaka Thomas P. , Jaenisch Rudolf
Published: October 2024

Bats are tolerant to highly pathogenic viruses such as Marburg, Ebola, and Nipah, suggesting the presence of a unique immune tolerance toward viral infection. Here, we compared severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of human and bat (Rhinolophus ferrumequinum) pluripotent cells and fibroblasts. Since bat cells do not express an angiotensin-converting enzyme 2 (ACE2) receptor that allows virus infection, we transduced the human ACE2 (hA) receptor into the cells and found that transduced cells can be infected with SARS-CoV-2. Compared to human embryonic stem cells-hA, infected bat induced Pluripotent Stem Cells (iPSCs)-hA produced about a 100-fold lower level of infectious virus and displayed lower toxicity. In contrast, bat embryonic fibroblast-hA produced no infectious virus while being infectable and synthesizing viral RNA and proteins, suggesting abortive infection. Indeed, electron microscopy failed to detect virus-like particles in infected bat fibroblasts in contrast to bat iPSCs or human cells, consistent with the latter producing infectious viruses. This suggests that bat somatic but not pluripotent cells have an effective mechanism to control virus replication. Consistent with previous results by others, we find that bat cells have a constitutively activated innate immune system, which might limit SARS-CoV-2 infection compared to human cells.
Helical coiled nucleosome chromosome architectures during cell cycle progression
Authors: McDonald Angus , Murre Cornelis , Sedat John W.
Published: October 2024

Recent studies showed an interphase chromosome architecture—a specific coiled nucleosome structure—derived from cryopreserved EM tomograms, and dispersed throughout the nucleus. The images were computationally processed to fill in the missing wedges of data caused by incomplete tomographic tilts. The resulting structures increased z-resolution enabling an extension of the proposed architecture to that of mitotic chromosomes. Here, we provide additional insights into the chromosome architecture that was recently published [M. Elbaum et al.,
Proc. Natl. Acad. Sci. U.S.A.
119
, e2119101119 (2022)]. We build on the defined chromosomes time-dependent structures in an effort to probe their dynamics. Variants of the coiled chromosome structures, possibly further defining specific regions, are discussed. We propose, based on generalized specific uncoiling of mitotic chromosomes in telophase, large-scale reorganization of interphase chromosomes. Chromosome territories, organized as micron-sized small patches, are constructed, satisfying complex volume considerations. Finally, we unveiled the structures of replicated coiled chromosomes, still attached to centromeres, as part of chromosome architecture.
The effect of service dogs on veterans’ romantic partners and relationships: A preliminary mixed-methods study
Authors: L. Williamson , G. Rath , K. Arisman , J. Moss , C.A. Dell
Published: October 2024

Romantic partners are often key supports for veterans diagnosed with posttraumatic stress disorder (PTSD). However, a PTSD diagnosis among veterans is often associated with lower relationship satisfaction and quality. To help reduce their PTSD symptomology, some veterans are more regularly relying on the help of service dogs (SDs). Relatively little is known about how SDs affect romantic relationships and veterans’ romantic partners. The current mixed-methods preliminary study explored the psycho-social effects of SDs on veterans’ romantic relationships and their partners from the romantic partners’ perspective. Romantic partners of veterans (
N
= 27) completed the Partnership Questionnaire and seven partners completed interviews. Scale results indicated overall low relationship quality, with relatively lower scores for couples’ tenderness/intimacy and togetherness/communication, and higher scores for their quarreling. Interview results indicated there were perceived relationship problems due to the veterans’ PTSD, but there were some relationship improvements since the SD had been supporting the veteran, including decreased quarreling and increased tenderness/intimacy and togetherness/communication. Romantic partners reported experiencing less resentment and stress, and increased relaxation, calmness, patience, happiness, and hope for the future because of the SDs. This study suggests that SDs can influence other aspects of veterans’ lives beyond their disability, such as helping veterans reconnect with their romantic partners.
Connecting the dots on connexin function
Authors: Short Ben
Published: October 2024

Two JGP studies (Sanchez et al. https://doi.org/10.1085/jgp.202313502; Kraujaliene et al. https://doi.org/10.1085/jgp.202413600) reveal how small differences in a pore-lining region alter both the gap junction and hemichannel function of connexin26 and connexin30.
A natural model for curved inflation
Authors: Vigneron Quentin , Larena Julien
Published: October 2024

Inflationary models with a non-zero background curvature require additional hypothesis or parameters compared to flat inflation and the procedure to construct them cannot be as simple as in the flat case. For this reason, there is no consensus on the primordial power spectrum that should be considered at large scales in a curved Universe. In this letter, we propose a model of curved inflation in which the usual canonical quantization and Bunch–Davies vacuum choice of the flat case can be considered. The framework is a recently proposed modification of general relativity (GR) in which a non-dynamical topological term is added to the Einstein equation. The model is universal as it is the same for any background curvature, and no additional parameters or hypothesis on the initial spatial curvature are introduced. This gives a natural and simple solution to the problem of constructing curved inflation, and at the same time provides an additional argument for this topological modification of general relativity.
Impact of stacking faults on the luminescence of a zincblende InGaN/GaN single quantum well
Authors: Gundimeda Abhiram , Kusch Gunnar , Frentrup Martin , Xiu Huixin , Shu Ruiying , Hofer Christina , Bagot Paul A J , Moody Michael P , Kappers Menno J , Wallis David J , Oliver Rachel A
Published: October 2024

In this paper, we investigate the optical properties of a zincblende InGaN single quantum well (SQW) structure containing stacking faults (SFs). Cathodoluminescence studies revealed the presence of sharp emission features adjacent to SFs, identified as quantum wires (Qwire) via their spatial anisotropy. Scanning transmission electron microscopy provided evidence of indium rich regions adjacent to SFs which intersect the QW along the [110] and [1–10] directions, whilst atom probe tomography revealed that the indium rich regions have an elongated structure, creating a Qwire. This work sheds light on the intricate relationship between SFs and Qwires in zincblende InGaN SQW structures, offering insights into the underlying mechanisms governing their optical behavior.
Design and testing of a microwave Doppler-based yield estimation system for machine-picked seed cotton
Authors: Li Yuhang , Feng Jingan , Zhang Feng , Diao Shengang , Chen Jing
Published: October 2024

Accurately obtaining crop yields is an important part of the precision agriculture technology system; with the increased mechanisation of cotton planting and harvesting, it has become particularly important to accurately obtain seed cotton yield data. In order to achieve accurate estimation of machine-picked seed cotton yield, this paper designs a machine-picked seed cotton yield estimation system based on microwave Doppler principle. Based on LabVIEW software, the signal acquisition circuit is designed; the power spectrum of the echo signal is estimated; the signal echo power is obtained; the relationship model between echo power and seed cotton mass is established by using multiple regression equations; and the reliability of the model is verified by using statistical methods. By adjusting the rotational speed of the fan, the wind speed at the inlet of the cotton pipeline was 10 m s−1, 15 m s−1 and 20 m s−1, and the yield estimation tests were carried out at the three wind speeds, and the data showed that the average absolute percentage errors of the estimation at the three wind speeds were 7.36%, 7.72% and 8.17%, and the mean squared errors were 2.699, 4.938 and 4.026, respectively. The test results show that the accuracy of seed cotton mass estimation under the three wind speeds basically meets the needs of the yield measurement system, and the systematic error of seed cotton yield estimation is the smallest when the wind speed is 10 m s−1.
EPVC: a novel initialization approach of visual-inertial integrated navigation
Authors: Gu Xiaobo , Zhou Yujie , Luo Dongxiang , Li Zeyu
Published: October 2024

The fusion of visual and inertial measurements in robotics community is growing in popularity since both of them have complementary perceptual information. Pre-initializing gyroscope bias and accelerometer bias of the inertial measurement unit (IMU) is a critical issue to achieve a better fusion performance, and the metric scale is another crucial element to be estimated. Current mainstream loosely-coupled initialization methods are unstable as they do not incorporate IMU information into the visual structure from motion. In addition, the accuracy of the tightly-coupled methods is limited since they do not use visual observations to compensate gyroscope bias and usually ignore them in close-form solution. In this paper, a visual-inertial (VI) initialization method which we refer to as epipolar plane normal vectors coplanarity constraint (EPVC) method is proposed to solve gyroscope bias. A step further, a novel analytical solution is presented to optimize other parameters. Comparing the proposed method with VI navigation systems-mono and inertial-only optimization through the publicly available EuRoC dataset, the results demonstrate that the proposed method outperforms the existing methods in estimating the gyroscope bias and scale, and with the increase of initialization time, the accelerometer bias error and gravity direction error have a clear diminishing tendency.
Delamination inspection in composite laminates with S0 Lamb wave using flexible macro-fiber composite transducers
Authors: Kou Xing , Casciaro Emanuele , Qian Cheng , Pei Cuixiang , Bettini Paolo
Published: October 2024

Delamination in composite laminates poses a serious threat to structural integrity in aerospace applications due to its potential to cause structural failure. Effective structural health monitoring methods are needed to identify such damage. The objective of this paper is to measure and localize delamination in a glass fiber reinforced polymer cross-ply composite laminate based on the S0 Lamb wave detection method, using the macro-fiber composite (MFC) as both actuator and receiver. To analyze the interaction behaviors between the excited S0 Lamb wave and delamination, the finite element models were established to simulate the Lamb wave propagation in composites, incorporating the local stiffness reduction method to model the delamination region. The simulation results indicate that the interaction behaviors between the excited S0 wave and the delamination occur mainly at the end of the delamination, and the generated new wave packets in the received signals can be used to identify the delamination. Furthermore, the S0 wave reflected from the end edge of delamination was used to localize the delamination. Reflection coefficients were found to vary significantly with delamination depth, and the delamination’s longitudinal position was accurately localized using time-of-flight extraction. Finally, a pitch-catch experiment with MFC transducers was conducted to detect an artificial delamination, demonstrating that it is a promising approach to inspect delamination accurately with end-edge reflected waves.
The advantages of employing i-a-SiOX:H as a buffer layer in hydrogenated amorphous silicon oxide solar cells
Authors: Belabbas Tayeb Youcef , Belfar Abbas
Published: October 2024

This study focuses on a p-i-n single junction solar cell made of hydrogenated amorphous silicon oxide (a-SiOx:H), aiming to enhance solar cell efficiency by mitigating the impact of discontinuities and mismatches occurring at the i/p defect-rich interface between the window layer and the absorber layer. To address this concern, the impact of adding a thin i-a-SiOx:H buffer layer between the p-a-SiOx:H window layer and the i-a-SiOx:H active layer was investigated through numerical modeling using the AMPS-1D (Analysis of Micro-electronic and Photonic Structures) computer program. Implementing these changes led to a remarkable increase in conversion efficiency, rising from 5.714% to an impressive 8.929%. The increase in short-circuit current (JSC), however, is due to improved quantum efficiency at short wavelengths between 350 and 550 nm. Furthermore, enhancing the built-in potential (Vbi) at the i/p interface, combined with the buffer layer’s appropriate band gap energy, increases VOC (open-circuit voltage) from 850 to 993 mV. The substantial improvement in the fill factor (FF) from 63.1 to 83.1% can be largely attributed to the smoothed band offset, primarily facilitated by the presence of the buffer layer at the p/i interface, which led to more efficient extraction of photogenerated holes. To ensure effective usage of the buffer layer, the thickness of a-SiOx:H (buffer layer) varied between 3 nm and 9 nm, while the p-type doping concentration of the same layer was adjusted between 0 and 1020 cm−3. In summary, adding a 3 nm thick a-SiOx:H buffer layer with an intermediate band gap and with a p-type doping concentration (NA) below 1018 cm−3 at the i/p interface improves the electrical and optical properties of the p-i-n solar cells (EFF = 8.951%; VOC = 0.994 V; FF = 83.1%; JSC = 10.842 mA.cm−2).
Design and error analysis of simple terahertz high birefringence microstructured fiber
Authors: Xu Lei-Lei , Yan De-Xian , Li Xiang-Jun , Zhang Le , Sun Shuai , Li Ji-Ning
Published: October 2024

High birefringence fibers are significant in the terahertz technology field, serving as waveguides for terahertz transmission. They are applicable in various fields such as communication, imaging. Integrating metal microstructures into polymer microstructured optical fibers can effectively modulate the transmission characteristics of the fiber, enhancing birefringence and reducing loss, thereby achieving better performance compared to traditional single-material fibers. This paper presents a structurally simple terahertz high birefringence microstructured fiber, where the introduction of gold microstructures enhances the birefringence of fiber, with a maximum birefringence of up to 1.089 × 10−2. We also discuss several manufacturing errors that may occur during the fiber fabrication process. The results indicate that the designed fiber exhibits significant manufacturing tolerance. Variations in the thickness and angle of the gold microstructures, as well as the angular offset of the elliptical cladding wall, peak-to-valley errors, and changes in the aspect ratio of the elliptical tube, have relatively minor effects on the overall transmission performance. The research findings provide insights for designing subsequent high birefringence terahertz fibers, thereby propelling advancements in this field. They offer a theoretical basis for the preparation of related microstructured fiber structures and provide valuable understanding for optimizing fiber manufacturing processes.
Thermal stability and anti-ablation performance of plasma spray coated-YSZ on Al2TiO5 modified novel ablative carbon-phenolic composites
Authors: Basingala Praveen Kumar , Neigapula Venkata Swamy Naidu
Published: October 2024

Despite ongoing challenges, ablative thermal protection systems (TPS) are among the most promising methods for safeguarding spacecraft during re-entry. The polyacrylonitrile (PAN)-based carbon fiber fabric(C)-reinforced with resorcinol phenol formaldehyde resin (RF) composites (C-RF) can be a potential candidate for TPS applications. This study investigates the influence of aluminium titanate (Al2TiO5/AT) and a highly efficient thermal barrier of coating (TB/TBCs) of yttria-stabilized zirconia (YSZ) powder on the thermal and ablative performance of the composites. The composites were prepared by compression moulding and YSZ was coated using plasma spray technique. Composites were produced with varying wt% of AT. Thermal stability and ablation performance of unmodified C-RF with modified YSZ-C-RF and YSZ-AT-C-RF composites were examined through thermogravimetric analysis (TGA) and oxyacetylene torch (OAT) test (4.0 MW m−2 for 60 s). Also, the phase composition and microstructure of the ablated surface were determined by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) techniques. The mass and linear ablation rates (MAR and LAR) of the composites after modifying the surface by YSZ-coatings were reduced. Furthermore, upon the introduction of AT particles and TBC of YSZ results in evidence of improving the thermal stability and the ablation resistance. The addition of 1 wt% AT particles and coating of YSZ have reduced MAR and LAR by 54.79% and 61.94%, respectively. This work offers a meaningful method to remarkably enhance the ablation performance of the modified C-RF and YSZ-AT-C-RF composites and can potentially find their application in aerospace industry.
Quantum circuit syntheses of Boolean matrix multiplication using only CNOT gates
Authors: Zheng Yuanmeng , Luo Qingbin , Li Qiang , Lv Yi , Liao Haoyu , Ding Lang , Shen Jinan
Published: October 2024

Boolean matrices and operations on Boolean matrices have become increasingly popular in quantum computing and quantum information because they can be used to represent quantum states and the corresponding operations. In this paper, we first give a quantum circuit direct synthesis of general Boolean matrix multiplication using Toffoli gates. We assign a qubit to each element of the matrix and add Toffoli gates at the corresponding positions where the matrix elements are multiplied according to the arithmetic of matrix multiplication. For n × p dimensional matrix A multiplied by p × m dimensional matrix B, np + pm + nm qubits and at most pmn Toffoli gates are used in total. Then, an improved heuristic algorithm based on matrix Hamming distance selection of CNOT gate is proposed to synthesize the quantum circuit of a matrix, without using wire switching and SWAP gates, using only CNOT gates. The results show that our method is as good as or better than the classical synthesis. Finally, the quantum circuit of Boolean matrix multiplication with at least one invertible or full-rank matrix using only CNOT gates is given, which is divided into five cases for discussion and analysis. For n × n dimensional invertible matrix A multiplied by n × m dimensional matrix B, nm qubits and at most mn
2 CNOT gates are used in total. For n × p dimensional column full-rank matrix A multiplied by p × m dimensional matrix B, nm qubits and at most pmn CNOT gates are used in total. The results show that this method uses less quantum resources to synthesize the quantum circuit of Boolean matrix multiplication. The correctness of the quantum circuits was verified by the Aer simulator of the IBM Quantum platform.
Fatigue and Autofrettage Analysis of Steel Sleeve Based on Precision Fit under Ultra High Pressure
Authors: Li Shangqing , Zhang Chunguang , Wu Ye , Wang Yu , Yu Xiaochen , An Lei
Published: October 2024

In order to ensure precision fit between steel sleeve and plunger, copper sleeve and the other parts of the ultra high pressure plunger pump, as well as increase the fatigue life of steel sleeve, this paper made the analysis of work process and fatigue life of ultra high pressure autofrettage steel sleeve of plunger pump based on both analytical method and FEM. The elastic-plastic boundary radius, radial stress and plastic zone displacement were obtained based on the elastic-plastic mechanics analysis of ultra high pressure steel sleeve. The functional relationship built related to precision fit among autofrettage pressure, inner diameter expectation and displacement could ensure the machining dimension of inner diameter of steel sleeve and realize the precise control of inner diameter of steel sleeve. The analytical method and FEM for calculating fatigue life was also proposed, which are verified by experiment. The research shows that machining dimension is determined by inner diameter expectation in the autofrettage process to ensure precision fit; autofrettage treatment can reduce the working stress level of the steel sleeve and extend the fatigue life remarkably. These conclusions contribute to guide the design of steel sleeve.
Effect of tensile speeds on mechanical properties of Young’s modulus and Poisson’s ratio of 3D-printed ABS-like specimens
Authors: Kajiwara Shuhei , Yamashita Shun , Matsueda Takahiro , Mizobe Koshiro , Kida Katsuyuki
Published: October 2024

Additive manufacturing (AM) is a well-known method of 3D printers. The AM method forms components by laminating thin layers. Therefore, this method can make prototypes of parts and does not involve any tooling or human interference. However, the mechanical parts made by the AM method have unique problems. In particular, the effect of the strain rate on the mechanical property of Young’s modulus and Poisson’s ratio has not been studied in detail. Therefore, we investigated the effect of strain rates on 3D-printed ABS-like specimens in this study. In order to investigate the effect of tensile speed on 3D-printed ABS-like specimens, tensile tests were conducted at 0.2 mm/min, 2 mm/min, 60 mm/min, 800 mm/min, and 1000 mm/min. We obtained the experimental results that Young’s modulus increased with increasing tensile speed. Also, the specimen broke at multiple points in high-speed tensile tests. Poisson’s ratio values for all tensile speeds were almost constant around 0.38.
High Temperature Oxidation Behaviours of NiCoCrAlY alloys with High Al Content
Authors: Zhang Jin , Ji Renyi , Nie Zhihua , Ning Xianjin , Mu Rende , Tan Chengwen
Published: October 2024

MCrAlY coatings are of paramount importance in the protection of hot-end components from thermal oxidation and corrosion. The Al content is a crucial factor in enhancing the oxidation resistance properties of the coatings. This paper studies the oxidation behaviors of Ni-27.5Co-17Cr-xAl-0.5Y (x = 12 and 16 wt.%) alloys with high Al content. Following an oxidation process at 1100 °C over a period of 100 h, both alloys exhibit the oxide scales primarily consist of Al2O3 with minor amount of Co(Ni)Al2O4 spinels. The increased Al content results in a higher proportion of β phase, thereby promoting the development of an oxide scale in response to thermal exposure. This study provides insights into the fabrication of high Al content MCrAlY coatings with potential applications in next-generation thermal barrier coatings.
Effect of Cold Rolling on the Microstructure and High Temperature Properties of 310S Heat-resistant Steel
Authors: Zhongyuan Zhao , You Yang , Zhenxin Duan , Xiaolei Song , Jingshi Zhang
Published: October 2024

The microstructure and high temperature properties of 310S heat-resistant steel were investigated before and after cold rolling with a deformation rate of 10% by using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffractometer (XRD) and tensile testing machine.The results showed that the microstructure of 310S heat-resistant steel remains unchanged with no formation of any new phase observed after cold rolling. The hardness is enhanced from 305.4HV prior to cold rolling to 321.6HV post cold rolling, exhibiting an augmentation of 16.2HV. The 310S heat-resistant steel is carried out a cold-rolling process with a deformation of 10% in the room temperature tensile test. The tensile strength exhibits an increase from 776.6MPa to 806.3MPa, with a difference of 29.7MPa.The yield strength has experienced a significant increase, from 554.4MPa to 679.6MPa, representing a substantial increment of 125.2MPa.The elongation decreased by 20.2%, from 61.9% to 41.7%, after cold rolling. The 310S heat-resistant steel with 0% deformation appears superplasticity at 750°C. The elongation rate reaches 113.1%. The 310S heat-resistant steel with 0% deformation appears fracture oxidation at 800°C. In the process of 700°C to 800°C, the tensile strength of 310S heat-resistant steel with 0% deformation is reduced by 101.9MPa, and the tensile strength of 310S heat-resistant steel with 10% deformation is reduced by 90.9MPa.
Facile synthesis of Fe3O4/Ti3C2Tx MXene/RGO aerogels with broadband microwave absorption and thermal insulation performance
Authors: Cheng Xin , Liu Xingmin , Wang Jijie , Hua Yutuo
Published: October 2024

The development of microwave absorbing materials with attributes such as low weight, broad absorption bandwidth, and superior thermal insulation performance is still challenging. In this study, Fe3O4 nanoparticles were anchored on Ti3C2Tx MXene/RGO nanosheets by one-step hydrothermal gelation method to prepare Fe3O4/Ti3C2Tx MXene/RGO (FeMR) hybrid aerogels. Perfect impedance matching and electromagnetic coupling effect were achieved by adjusting the composition ratio of FeMR aerogels, so exceptionally outstanding microwave absorption performance was obtained. FeMR aerogel at 2.90 mm thickness, effective absorption bandwidth (EAB) up to 8.10 GHz. Simultaneously, FeMR aerogels have has good thermal insulation performance. After heating at 300°C for 60 min, the aerogel can still isolate the thermal radiation of about 155 °C. This work demonstrates a simple method for preparing lightweight, broadband electromagnetic wave absorption and heat insulation three-dimensional MXene-based aerogels, which provides inspiration for the structural design and potential applications of EWA materials.
Effect of pre-strain on dynamic mechanical properties of Ti-6Cr-5Mo-5V-4Al titanium alloy
Authors: He Shulin , Li Rui , Xiao» Kaikai , Li Changheng , Yu Yang
Published: October 2024

The effect of quasi-static pre-deformation on the dynamic properties of Ti-6Cr-5Mo-5V-4Al titanium alloy was studied. The results revealed that as the pre-tension deformation increased, the average dynamic flow stress was slightly decreased while the dynamic uniform plastic strain and the maximum absorbed energy were improved obviously and the largest value existed when the deformation reached 6.8%. As the pre-tension deformation progressively increased, the dynamic performance exhibited a marked decline. Conversely, with the increase of the pre-compression deformation, the dynamic flow stress experienced a substantial enhancement, but the dynamic uniform plastic and the maximum absorbed energy significantly declined which showed that the pre-compression deformation did harm to the dynamic mechanical properties of Ti-6Cr-5Mo-5V-4Al titanium alloy.
Development of a rapid analysis system for pre-cooling process of large LNG full-capacity storage tank
Authors: Zhao Yunfei , Qian Caifu , Wu Zhiwei , Zhang Baohe , Wu Hao , Xia Huabo
Published: October 2024

In this paper, a quick analysis system for the pre-cooling process of large LNG tank was developed, based on ANSYS-Python. The system has the functions of establishing geometric model automatically, dividing grid automatically and solving automatically. Operation of the system is simple with high efficiency. Comparison with the field data results found that the quick analysis system is accurate to meet the requirements of engineering application. The quick analysis system is helpful to optimize the pre-cooling process and the structure of large LNG full-capacity tanks
Study on the effects of accident-tolerant fuels on the safety of CPR1000 nuclear power plants
Authors: Liu Mengying , Xu Haode , Liu Pingping
Published: October 2024

In this paper, CPR1000 Nuclear power plant was taken as the reference unit. According to CPR1000 Probabilistic Safety Analysis (PSA), the Large Break loss of coolant accident (LOCA), Medium Break LOCA, Small Break LOCA, Station Blackout (SBO), Total Loss of Feed water (TLOFW) and Anticipated transient without trip (ATWT) with Loss of Main Feed water (LOMF) were selected as the representative accident scenarios. The house holding deterministic programs LOCUST were used to analyze each of the above selected scenarios for five different accident tolerant fuels (ATF). The effects on accident process, reactor core damage time, system success criteria and personnel response time were analyzed under the above scenarios. The above results for the five ATF materials were compared to those for standard UO2-Zr in the same scenarios, then some useful conclusions were obtained which can be used to support ATF material selection. In the end, based on the deterministic calculations, the effects of different ATF materials on CPR1000 PSA results such as core damage frequency (CDF) were evaluated in detail with traditional PSA software Risk Spectrum. According to the results, ATFs have some advantages on core damage time, success criteria or operators’ action time window. But the CDF was changed little compared to standard UO2-Zr system. Through the studies, it is found the most important thing is that due to the much longer time windows some new plant modifications can be provided to mitigate the accidents which can contribute to the plant safety and decrease risk more.
Theoretical study of the mechanism of 2F-molecular sieve domain chiral transition of Asn molecules
Authors: Zhu Ying , Bao Jie , Chen Hongbin
Published: October 2024

Using density functional theory at the level of oniom (b3lyp/6-31g (d, p): uff), we investigated the chiral transition process of the Asparagine molecule in 2F-MOL. Furthermore, a complete chiral transition path reaction potential energy surface was drawn by looking for the extreme value point structures including the transition state and intermediate. The results show that the hydrogen atom on the chiral carbon atom of S-Asparagine molecule can transfer to the other side of the carbon atom via the oxygen atoms of carboxyl atoms as a bridge, to achieve the chiral transition of Asparagine molecule from S-type to R-type. On this path there is four intermediate and five transition states. The biggest reaction energy barrier is 243.9089KJ/mol derived from the fourth transition state TS1-R-Asn@2F-MOL.