bluuebunny/crossref_metadata_2025 huggingface dataset:
Capillary effects and consolidation kinetics during selective laser melting of 316L powder
Authors: Voroshilov Evgeniy S. , Mosina Rinetta M. , Gruzd Svetlana A. , Ivantsov Andrey O. , Khlybov Oleg A. , Lyubimova Tatyana P. , Krivilyov Mikhail D.
Published: April 2024

Selective laser melting (SLM) technology has the advantage of quickly producing complex-shaped parts. To achieve good mechanical properties, it's vital to minimize defects that can occur because of high residual porosity if incorrect processing techniques are used. One effective way to prevent defects is by using computer simulations of underlying processes before printing in the industry. This paper presents a reduced-order numerical model of SLM processing that accurately predicts material porosity by focusing on the key mechanisms that affect the melting and consolidation processes. The focus is on the formation of defects and the expected time that is required until the consolidation of a powder bed is completed. Then the elasticity of the SLM processed materials near defects is analyzed. The modeling results for powder consolidation are shown for comparison with experimental data on stainless steel 316L powder during SLM. This information can be further used for proper selection of SLM parameters such as the scanning speed and the power of the laser source.
Multiscale thermodynamics of Ni/Al energetic structural materials under shock
Authors: Liu Rui , Zhang Wei , Wang Kunyu , Chen Pengwan , Ge Chao , Wang Haifu
Published: April 2024

The influence of microstructure on the response of energetic structural materials (ESMs) under shock conditions remains inadequately quantified, and the energy release process is not thoroughly understood. In this work, taking the classical Ni/Al ESM as an example, the shock response was investigated by the shock compression theory with the microstructure-based chemical reaction kinetics model. This theory mainly refers to the equation of the state of multi-component materials with mixture rule, and the reaction at the particle contact interface is built to form the multiscale thermodynamics model. The physical states of material after shock, including relative volume, temperature, and extent of reaction, were analyzed. The results revealed the effect of the burn velocity, particle size and molar ratio on the shock response. Furthermore, the model facilitates a comprehensive understanding of energy release, the extent of the intermetallic reaction, and the oxidation reaction. Despite the involvement of only a small portion of materials in the oxidation reaction, the energy release proportion was comparable to that of the intermetallic reaction. Additionally, insights into the effect of the microstructure on the energy release revealed by the model matched the tests well.
Newly observed low-lying Ω = 1 state of PbO
Authors: Enomoto Katsunari , Tojo Taichi , Kobayashi Kaori , Kuma Susumu , Hiramoto Ayami , Miyamoto Yuki , Baba Masaaki
Published: April 2024

High-resolution spectroscopy of lead monoxide was performed in a range of 22 400–25 300 cm−1. A new Ω = 1 state located between the a1 and A0+ states was observed, and it is labeled c1. Spectroscopic constants, including the hyperfine interaction coefficient, were determined for the a1 and c1 states. The vibrational levels of these two electronic states are located closely to each other, and the interaction between them causes gradual exchange of electronic state properties in our observation wave number range. Our observation poses a question for the band assignment for the b0− state, which has some resemblance with this c1 state.
Hydrodynamics and propulsion of a hydrofoil undergoing leading-edge pitching and traveling wave-based surface undulation
Authors: Shukla Sarvesh , Sharma Atul , Agrawal Amit , Bhardwaj Rajneesh
Published: April 2024

We numerically study the fluid–structure interaction of a free-stream flow across a hydrofoil pitching at its leading edge with superimposed traveling wave-based surface undulations. We utilize an in-house code that employs the sharp interface immersed boundary method and consider a constant pitching amplitude θ0 = 5°, a constant local amplitude-to-thickness ratio AL=0.15, and wave number K = 20 of surface undulation. We compare the effect of surface undulation on a pitching hydrofoil with that of a hydrofoil undergoing pure pitching or experiencing pure surface undulation. The findings reveal that surface undulation on the pitching hydrofoil increases thrust on the hydrofoil. The onset of asymmetry in the vortex street occurs at a lower pitching Strouhal number (St) due to the early formation of a vortex dipole. In addition to the presence of an asymmetric inverse von Kármán vortex street, higher pitching frequencies reveal re-deflection of the asymmetric inverse von Kármán vortices. We quantified dynamics of vortex dipole to explain the occurrence of asymmetric and re-deflected reverse von Kármán vortex street. Furthermore, the analysis reveals an optimum combination of St and phase speed that yields higher propulsive efficiency, as both motions compete in generating thrust. A linearly superimposed scaling analysis for the time-averaged thrust of the combined motion is also presented. The computations and scaling are found to be in good agreement.
Modulation of supramolecular structure by stepwise removal of tert-butyl groups from tetraazaperopyrene derivatives on Ag(111)
Authors: Fu Boyu , Guan Yurou , Yuan Wei , Geng Jianqun , Hao Zhenliang , Ruan Zilin , Sun Shijie , Zhang Yong , Xiong Wei , Gao Lei , Chen Yulan , Ji Wei , Lu Jianchen , Cai Jinming
Published: April 2024

Tert-butyl functional groups can modulate the self-assembly behavior of organic molecules on surfaces. However, the precise construction of supramolecular architectures through their controlled thermal removal remains a challenge. Herein, we precisely controlled the removal amount of tert-butyl groups in tetraazaperopyrene derivatives by stepwise annealing on Ag(111). The evolution of 4tBu-TAPP supramolecular self-assembly from the grid-like structure composed of 3tBu-TAPP through the honeycomb network formed by 2tBu-TAPP to the one-dimensional chain co-assembled by tBu-TAPP and TAPP was successfully realized. This series of supramolecular nanostructures were directly visualized by high resolution scanning tunneling microscopy. Tip manipulation and density functional theory calculations show that the formation of honeycomb network structure can be attributed to the van der Waals interactions, N–Ag–N coordination bonds, and weak C–H⋯N hydrogen bonds. Further addition of two tert-butyl groups (6tBu-TAPP) leads to a completely different assembly evolution, due to the fact that the additional tert-butyl groups affect the molecular adsorption behavior and ultimately induce desorption. This work can possibly be exploited in constructing stable and long-range ordered nanostructures in surface-assisted systems, which can also promote the development of nanostructures in functional molecular devices.
Coexistence of large anomalous Nernst effect and large coercive force in amorphous ferrimagnetic TbCo alloy films
Authors: Odagiri Miho , Imaeda Hiroto , Yagmur Ahmet , Kurokawa Yuichiro , Sumi Satoshi , Awano Hiroyuki , Tanabe Kenji
Published: April 2024

The anomalous Nernst effect (ANE) has garnered significant interest for practical applications, particularly in energy harvesting and heat flux sensing. For these applications, it is crucial for the module to operate without an external magnetic field, necessitating a combination of a large ANE and a substantial coercive force. However, most materials exhibiting a large ANE typically have a relatively small coercive force. In our research, we have explored the ANE in amorphous ferrimagnetic TbCo alloy films, noting that the coercive force peaks at the magnetization compensation point (MCP). We observed that transverse Seebeck coefficients are amplified with Tb doping, reaching more than 1.0 μV/K over a wide composition range near the MCP, which is three times greater than that of pure Co. Our findings indicate that this enhancement is primarily due to direct conversion, a product of the transverse thermoelectric component and electrical resistivity. TbCo films present several significant advantages for practical use: a large ANE, the capability to exhibit both positive and negative ANE, the flexibility to be deposited on any substrate due to their amorphous nature, a low thermal conductivity, and a large coercive force. These attributes make TbCo films a promising material for advancing ANE-based technologies.
Study of the adsorption sites of high entropy alloys for CO2 reduction using graph convolutional network
Authors: Oliaei H. , Aluru N. R.
Published: April 2024

Carbon dioxide reduction is a major step toward building a cleaner and safer environment. There is a surge of interest in exploring high-entropy alloys (HEAs) as active catalysts for CO2 reduction; however, so far, it is mainly limited to quinary HEAs. Inspired by the successful synthesis of octonary and denary HEAs, herein, the CO2 reduction reaction (CO2RR) performance of an HEA composed of Ag, Au, Cu, Pd, Pt, Co, Ga, Ni, and Zn is studied by developing a high-fidelity graph neural network (GNN) framework. Within this framework, the adsorption site geometry and physics are employed through the featurization of elements. Particularly, featurization is performed using various intrinsic properties, such as electronegativity and atomic radius, to enable not only the supervised learning of CO2RR performance descriptors, namely, CO and H adsorption energies, but also the learning of adsorption physics and generalization to unseen metals and alloys. The developed model evaluates the adsorption strength of ∼3.5 and ∼0.4 billion possible sites for CO and H, respectively. Despite the enormous space of the AgAuCuPdPtCoGaNiZn alloy and the rather small size of the training data, the GNN framework demonstrated high accuracy and good robustness. This study paves the way for the rapid screening and intelligent synthesis of CO2RR-active and selective HEAs.
Feasibility of GaAs/AlGaAs quantum cascade laser operating above 6 THz
Authors: Ushakov D. V. , Afonenko A. A. , Afonenko An. A. , Khabibullin R. A. , Fadeev M. A. , Gavrilenko V. I. , Dubinov A. A.
Published: April 2024

A band design of a quantum cascade laser with a generation frequency higher than 6 THz and an active region based on four GaAs/Al0.14Ga0.86As quantum wells is proposed. Calculations were carried out based on the solution of the Schrödinger equation taking into account the dephasing of quantum states, as well as a closed system of balance equations. The temperature dependences of the gain at frequencies of 6.3–6.6 THz were calculated for the proposed quantum cascade laser with a double metal waveguide. Features of the proposed laser structure include two injection quantum wells and the suppression of non-radiative transitions between laser levels. According to calculations, this provides the maximum operating temperature of up to 81 K at 6.4 THz. The results of this study open up the way for quantum cascade lasers based on GaAs/AlGaAs to operate at frequencies above 6 THz.
Experimental and numerical study on flow mixing and combustion characteristics of a novel multibypass integrated combustor
Authors: Ren Dongliang , Fan Weijun , Zhang Rongchun
Published: April 2024

The integrated design of multibypass augmented/ramjet combustors can reduce the weight of turbine-based combined cycle (TBCC) engines and improve the thrust-to-weight ratio, but low-resistance mixing and efficient stable combustion of multiple airflows over short distances are necessary prerequisites. In this study, a novel structure for a TBCC multibypass integrated augmented/ramjet combustor is proposed. The influence of the inlet aerodynamic parameters on the flow field, mixing efficiency, flow loss, and combustion performance of the combustor under different working modes was obtained via experimental and numerical methods. The experimental results show that the outlet mixing efficiency is greater than 86% in the double-bypass mode (DB-mode). While the triple-bypass mode (TB-mode) has a larger decrease, the total pressure loss is slightly reduced (by approximately 0.5%). The opening of the ram duct has a significant impact on the flow field, resulting in different rules for the influence of the inlet temperature on the outlet mixing efficiency: in the DB-mode, the mixing efficiency decreases with increasing inlet temperature, while the rule is completely opposite after entering the TB-mode. Because the dominant role of the two mixing zones in the flow field changes with the velocity, the inlet velocity has a significant impact on the mixing efficiency in the flow direction. The combustion simulation results show that the combustion efficiency in the DB-mode is almost always above 90% and the high-temperature zone is mainly concentrated downstream of the integrated strut. The radial temperature gradient increases and the combustion efficiency decreases in the TB-mode.
Alignment of fibrous J-aggregates and the resulting macroscopic optical anisotropy observed in static solution
Authors: Harada Mio , Yatsuhashi Tomoyuki , Sakota Kenji
Published: April 2024

J-aggregates, which are supramolecular assemblies that exhibit unique optical properties owing to their excitonic interactions, have potential applications in artificial light-harvesting systems and fluorescence biosensing. Although J-aggregates are formed in solution, in situ observations of their structures and behaviors in solution remain scarce. In this study, we investigated the J-aggregates of 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate [DiIC18(3)] in methanol/water (M/W) binary solvents using fluorescence imaging as well as polarized absorption and fluorescence measurements to explore the relationship between their structure and macroscopic optical properties under static conditions. Fluorescence images revealed that the DiIC18(3) J-aggregates have fibrous structures in the M/W = 44/56 (v/v) binary solvent. We measured the polarization-angle dependence of the fluorescence intensity of the fibrous J-aggregates to determine the direction of their transition dipole moment. Furthermore, the J-band absorbance was dependent on the polarization angle of the linearly polarized incident light, even in the absence of an external force such as that generated by a flow or stirring, indicating that the J-aggregates “spontaneously” aligned in solution. We also monitored the time evolution of the degree of alignment of the fibrous J-aggregates, which revealed that the formation and elongation of the fibers induced their alignment, resulting in the observed macroscopic optical anisotropy in solution.
Optimal standoff distance for a highly focused microjet penetrating a soft material
Authors: Igarashi Daichi , Kimura Kento , Endo Nanami , Yokoyama Yuto , Kusuno Hiroaki , Tagawa Yoshiyuki
Published: April 2024

A needle-free injector using a highly focused microjet has the potential to minimize the invasiveness of drug delivery. In this study, the jet penetration depth in a soft material—which is a critical parameter for practical needle-free injections—was investigated. We conducted jet penetration experiments by varying the inner diameter of the injection tube and the standoff distance between the meniscus surface and the soft material. Interestingly, the results showed that the penetration depths peaked at certain distances from the meniscus, and the positions shifted further away as the inner diameter was increased. By analyzing the velocity distribution of the microjet, the peak positions of the penetration depth and the maximum velocities were inconsistent due to the effects of the jet shape. To account for this, we introduce the concept of the “jet pressure impulse,” a physical quantity that unifies the velocity and jet shape. However, direct estimation of this parameter from experimental data is challenging due to limitations in spatiotemporal resolution. Therefore, we used numerical simulations to replicate the experimental conditions and calculate the jet pressure impulse. Remarkably, the results show that the jet pressure impulse has peak values, which is consistent with the penetration depth. In addition, there is a correlation between the magnitude of the jet pressure impulse and the penetration depth, highlighting its importance as a key parameter. This study underlines the importance of the jet pressure impulse in controlling the penetration depth of a focused microjet, providing valuable insights for the practical use of needle-free injection techniques.
Grasping the behavior of magnetorheological fluids in gradient pinch mode via microscopic imaging
Authors: Kubík Michal , Žáček Jiří , Gołdasz Janusz , Nečas David , Sedlačík Michal , Blahuta Jiří , Bańkosz Wojciech , Sapiński Bogdan
Published: April 2024

Magnetorheological (MR) fluids are suspensions of micrometer-sized ferromagnetic particles in a carrier fluid, which react to magnetic fields. The fluids can be operated in several fundamental modes. Contrary to the other modes, the rheology and microstructure formation of the MR fluid in the gradient pinch mode have been studied to a far lesser extent. The magnetic field distribution in the flow channel is intentionally made non-uniform. It is hypothesized that the Venturi-like contraction is achieved via fluid property changes, leading to a unique behavior and the presence of a pseudo-orifice. The main goal is to investigate the presence of the Venturi-like contraction effect in the fluid by means of optical imaging and hydraulic measurements. To accomplish the goal, a unique test rig has been developed including a fluorescence microscope and MR valve prototype. The Venturi-like contraction hypothesis was confirmed. The results indicate that the effective flow channel size decreases by 92% at the maximum magnetic flux applied. This has a direct impact on the flow characteristics of the MR valve. The variation of the pressure–flow rate curve slope with magnetic field was demonstrated. The results provide valuable information for understanding the rheology and microstructure formation mechanism in MR fluids in the pinch mode.
The social and economic dimensions of one of the world’s longest-operating shark fisheries
Authors: Braccini Matias , Watt Maddison , Syers Clinton , Blay Nick , Navarro Matthew , Burton Michael
Published: April 2024

Context Social and economic information is limited for coastal commercial and recreational fisheries, particularly shark fisheries, which are perceived as unsustainable and as targeting sharks for fins. Aims To characterise the social and economic dimensions of one of the world’s few long-standing sustainable shark fisheries. Methods We reviewed historic data and surveyed stakeholders to understand the economic and social dimensions of the shark fishery currently operating in Western Australia. Key results Since the fishery’s historic peak, there has been a substantial reduction in the number of operating vessels and ports due to management intervention. For the vessels that have remained, catches and catch rates increased through time. Fishers sold only flesh and fins, whereas processors also sold cartilage. Revenue mostly originates from the domestic sale of flesh, not fins. This fishery provides additional social and economic returns through the employment of an average of 102 people per annum, the supply of local fresh seafood to communities and the expenditure of most of operational costs in local government areas. In addition, the average annual market value through the supply chain was A$32.6 × 106 (US$20.9 × 106). Conclusions Our study is the first step towards a more comprehensive valuation of the societal contribution of sustainable shark fisheries. Implications This novel information has a range of applications, from developing social and economic objectives in fisheries harvest strategies to empowering government agencies when making decisions on natural resource management.
SARS-CoV-2 nsp15 endoribonuclease antagonizes dsRNA-induced antiviral signaling
Authors: Otter Clayton J. , Bracci Nicole , Parenti Nicholas A. , Ye Chengjin , Asthana Abhishek , Blomqvist Ebba K. , Tan Li Hui , Pfannenstiel Jessica J. , Jackson Nathaniel , Fehr Anthony R. , Silverman Robert H. , Burke James M. , Cohen Noam A. , Martinez-Sobrido Luis , Weiss Susan R.
Published: April 2024

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of deaths since its emergence in 2019. Innate immune antagonism by lethal CoVs such as SARS-CoV-2 is crucial for optimal replication and pathogenesis. The conserved nonstructural protein 15 (nsp15) endoribonuclease (EndoU) limits activation of double-stranded (ds)RNA-induced pathways, including interferon (IFN) signaling, protein kinase R (PKR), and oligoadenylate synthetase/ribonuclease L (OAS/RNase L) during diverse CoV infections including murine coronavirus and Middle East respiratory syndrome (MERS)-CoV. To determine how nsp15 functions during SARS-CoV-2 infection, we constructed a recombinant SARS-CoV-2 (nsp15
mut
) expressing catalytically inactivated nsp15, which we show promoted increased dsRNA accumulation. Infection with SARS-CoV-2 nsp15
mut
led to increased activation of the IFN signaling and PKR pathways in lung-derived epithelial cell lines and primary nasal epithelial air–liquid interface (ALI) cultures as well as significant attenuation of replication in ALI cultures compared to wild-type virus. This replication defect was rescued when IFN signaling was inhibited with the Janus activated kinase (JAK) inhibitor ruxolitinib. Finally, to assess nsp15 function in the context of minimal (MERS-CoV) or moderate (SARS-CoV-2) innate immune induction, we compared infections with SARS-CoV-2 nsp15
mut
and previously described MERS-CoV nsp15 mutants. Inactivation of nsp15 had a more dramatic impact on MERS-CoV replication than SARS-CoV-2 in both Calu3 cells and nasal ALI cultures suggesting that SARS-CoV-2 can better tolerate innate immune responses. Taken together, SARS-CoV-2 nsp15 is a potent inhibitor of dsRNA-induced innate immune response and its antagonism of IFN signaling is necessary for optimal viral replication in primary nasal ALI cultures.
WNK kinase is a vasoactive chloride sensor in endothelial cells
Authors: Garrud Tessa A. C. , Bell Briar , Mata-Daboin Alejandro , Peixoto-Neves Dieniffer , Collier Daniel M. , Cordero-Morales Julio F. , Jaggar Jonathan H.
Published: April 2024

Endothelial cells (ECs) line the wall of blood vessels and regulate arterial contractility to tune regional organ blood flow and systemic pressure. Chloride (Cl
−
) is the most abundant anion in ECs and the Cl
−
sensitive With-No-Lysine (WNK) kinase is expressed in this cell type. Whether intracellular Cl
−
signaling and WNK kinase regulate EC function to alter arterial contractility is unclear. Here, we tested the hypothesis that intracellular Cl
−
signaling in ECs regulates arterial contractility and examined the signaling mechanisms involved, including the participation of WNK kinase. Our data obtained using two-photon microscopy and cell-specific inducible knockout mice indicated that acetylcholine, a prototypical vasodilator, stimulated a rapid reduction in intracellular Cl
−
concentration ([Cl
−
]
i
) due to the activation of TMEM16A, a Cl
−
channel, in ECs of resistance-size arteries. TMEM16A channel-mediated Cl
−
signaling activated WNK kinase, which phosphorylated its substrate proteins SPAK and OSR1 in ECs. OSR1 potentiated transient receptor potential vanilloid 4 (TRPV4) currents in a kinase-dependent manner and required a conserved binding motif located in the channel C terminus. Intracellular Ca
2+
signaling was measured in four dimensions in ECs using a high-speed lightsheet microscope. WNK kinase-dependent activation of TRPV4 channels increased local intracellular Ca
2+
signaling in ECs and produced vasodilation. In summary, we show that TMEM16A channel activation reduces [Cl
−
]
i
, which activates WNK kinase in ECs. WNK kinase phosphorylates OSR1 which then stimulates TRPV4 channels to produce vasodilation. Thus, TMEM16A channels regulate intracellular Cl
−
signaling and WNK kinase activity in ECs to control arterial contractility.
Radiation protection in a cohort of healthcare workers: knowledge, attitude, practices, feelings and IR-exposure in French hospitals
Authors: Baudin Clémence , Vacquier Blandine , Thin Guillemette , Chenene Lamine , Guersen Joël , Partarrieu Isabelle , Louet Martine , Ducou le Pointe Hubert , Mora Stéphanie , Verdun-Esquer Catherine , Lestavel Philippe , Rousseau Frédéric , Roy Hervé , Bensefa-Colas Lynda , Boyer Louis , Bernier Marie-Odile
Published: April 2024

The number of healthcare workers occupationally exposed to ionizing radiation (IR) is increasing every year. As health effects from exposure to low doses IR have been reported, radiation protection (RP) in the context of occupational activities is a major concern. This study aims to assess the compliance of healthcare workers with RP policies, according to their registered cumulative dose, profession, and perception of radiation self-exposure and associated risk. Every healthcare worker from one of the participating hospitals in France with at least one dosimetric record for each year 2009, 2014, and 2019 in the SISERI registry was included and invited to complete an online questionnaire including information on the worker’s occupational exposure, perception of IR-exposure risk and RP general knowledge. Hp(10) doses were provided by the SISERI system. Multivariate logistic regressions were used. Dosimeter wearing and RP practices compliance were strongly associated with ‘feeling of being IR-exposed’ (OR = 3.69, CI95% 2.04–6.66; OR = 4.60, CI95% 2.28–9.30, respectively). However, none of these factors was associated with RP training courses attendance. The main reason given for non-compliance is unsuitability or insufficient numbers of RP devices. This study provided useful information for RP policies. Making exposed workers aware of their own IR-exposure seems to be a key element to address in RP training courses. This type of questionnaire should be introduced into larger epidemiological studies. Dosimeter wearing and RP practices compliance are associated to feeling being IR-exposed. RP training courses should reinforce workers’ awareness of their exposure to IR.
Calibration and pose measurement of a combined vision sensor system for industrial robot grasping of brackets
Authors: Jiang Tao , Deng Wenjun , Yin Le , Yang Kaicheng , Wang Yanfen , Zhou Hongwei
Published: April 2024

Recently, visual sensing measurement and its application in industrial robot operations have been widely researched, promoting the development of instrumentation and automation. This study proposes a combined vision sensor system for robot grasping, focusing on combined sensor system calibration and bracket pose measurements. The system configuration and working strategy of the combined vision system are introduced. Thereafter, the calibration of the combined vision coordinate systems is presented, wherein a global vision system acts as the external measuring equipment for accurately calibrating the local vision. Furthermore, a pose estimation method using a local vision system (LVS) is proposed, including morphology-based image enhancement and principal component analysis based corner recognition methods. Verification experiments, including combined calibration and bracket pose measurements, were performed to validate the effectiveness and accuracy of the proposed combined vision measurement strategy. The results demonstrated that the proposed system applies to industrial robot grasping of brackets. In addition, the proposed robot-sensor calibration method improves calibration accuracy. Finally, the proposed corner detection method is effective and accurate for different bracket detection applications. This study provides a system that improves robot grasping results by considering key factors, such as vision measurement accuracy, and calibration methods.
Deep learning-assisted dual-modal tomography for phase flow rate estimation in two-phase oil-water flow systems
Authors: Ziaul Arif M , Lähivaara Timo , Vauhkonen Marko
Published: April 2024

Accurately estimating phase flow rates in multiphase systems is crucial for many industries, where precise measurements are essential for operational efficiency and safety. Addressing this issue, this paper introduces an approach that employs deep learning-assisted dual-modal electromagnetic flow tomography (EMFT) and electrical tomography (ET) to predict both oil and water flow rates in two-phase oil-water flows. To facilitate the generation of the data, we first simulate diverse flow conditions using COMSOL Multiphysics software and the convection–diffusion equation, aiming to create a realistic representation of two-phase oil-water flows. The dual-modal system measurement data, generated from these simulations and simulated by using a dense finite element mesh, provide reliable inputs for the deep learning model. Moreover, this study also integrates experimental data into both the training and testing phases, improving the ability of the proposed approach to estimate flow rates accurately in practical investigations. The results from laboratory experiments demonstrate the potential of the deep learning-assisted dual-modal ET and EMFT approach in effectively resolving the challenges of estimating flow rates in two-phase oil-water flow systems. By combining the deep learning capabilities with dual-modal tomography, this study offers valuable insights for future applications and represents a significant step forward in the field of multiphase flow rate estimation.
Indentation-induced plastic behavior of nanotwinned CuNi alloy: an atomic simulation
Authors: Zhang Can , Shi Mingxing
Published: April 2024

This study uses molecular dynamics simulations to explore the mechanical properties of a nano-twinned copper–nickel alloy during indentation. We investigate the impact of twin boundary (TB) angles and spacing on the alloy’s behavior. The plastic deformation process is primarily driven by dislocation generations, slips, and TB interactions, directly affecting the alloy’s hardness. Significant findings include: (1) hardness initially decreases, then increases with increasing TB angle θ, and for TB spacing d greater than 1.25 nm, hardness can be predicted using a simple proposed model; (2) dislocation density ρ experiences significant variations, leveling off at an indentation depth around 1.0 nm; (3) when TB spacing d exceeds 1.25 nm, plastic deformation is dominated by dislocation nucleation, slips, and boundary interactions, while smaller spacings lead to TB migration and the presence of independent dislocation loops, giving rise to force fluctuations along indentation.
SnO2 QDs sensitized ZnFe2O4 spheres with enhanced acetone sensing performance
Authors: Yuan Qiming , Li Weichao , Xia Zhangcheng , Hu Jingjie , He Lifang , Jin Ling , Zhang Liqiang , Chu Xiangfeng , Zhang Kui
Published: April 2024

Herein, SnO2 QDs (<10 nm) with small size instead of conventional nanoparticles was employed to modify ZnFe2O4 to synthesize porous and heterogeneous SnO2/ZnFe2O4 (ZFSQ) composites for gas sensing. By an immersion process combined with calcination treatment, the resultant porous ZFSQ composites with different contents of SnO2 QDs were obtained, and their sensing properties were investigated. Compared with bare ZnFe2O4 and SnO2 QDs, porous ZFSQ composites based-sensors showed much improved sensor response to acetone. For contrast, the sensor performance of ZFSQ composites was also compared with that of ZnFe2O4 sphere modified by SnO2 nanoparticles with different size. The porous ZFSQ composite with 5 wt% SnO2 QDs (ZFSQ-5) showed a better acetone sensing response than that of other ZFSQ composites, and it exhibited a high response value of 110–100 ppm of acetone and a low detection limit of 0.3 ppm at 240 °C. In addition to the rich heterojunctions and porous structure, the size effect of SnO2 QDs was other indispensable reasons for the improved sensor performance. Finally, the ZFSQ-5 composite sensor was attempted to be applied for acetone sensing in exhaled breath, suggesting its great potential in monitoring acetone.
Spin coated ultrathin PEDOT:PSS/SWCNT film with high electronic conductivity
Authors: Zhong Yifan , Li Bin , Wang Yu , Fu Shaoge , Deng Jia , Li Guangming , Zhao Haili , Chen Tao
Published: April 2024

Conductive Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively used as non-metallic electrodes. However, the relatively low electrical conductivity of pristine PEDOT:PSS film restricts its further application. Although doping high content conductive filler or increasing the film thickness are effective for enhancing the electrical property, the transparency is sacrificed, which limits the application of PEDOT:PSS films. In this study, preparing PEDOT:PSS composite film with highly conductive and transparent property was the primary purpose. To achieve this goal, single-walled carbon nanotubes (SWCNTs) and dimethyl sulfoxide (DMSO) was chosen to composite with PEDOT:PSS. The spin-coated SWCNT/PEDOT:PSS composite film exhibited excellent electrical conductivity and transparency. The electrical conductivity of composite film with desired transmittance property (78%) reached the highest value (1060.96 S cm−1) at the SWCNTs content was 6 wt%. Under the modification process applied in this work, the non-conductive PSS was partially removed by incorporated DMSO and SWCNTs. Then, the molecular chains of PEDOT stretched and adsorbed onto the surface of SWCNTs, forming a highly efficient three-dimensional conductive structure, which contributed to the enhancement of electrical conductivity and transparency. Additionally, the spin-coating process allowed for the reduction of film thickness, ensuring better transparency. This research contributed to expanding the further applications of PEDOT:PSS films in high-performance transparent film electrodes.
Sign-changing bubble tower solutions for a Paneitz-type problem
Authors: Chen Wenjing , Huang Xiaomeng
Published: April 2024

This paper is concerned with the following biharmonic problem

{

Δ
2

u
=

|

u

|

8

N
−
4

u

in 
 
Ω∖

B

(

ξ
0

,
ε
)

―

,

u
=
Δ
u
=
0

on 
 
∂

(
Ω∖

B

(

ξ
0

,
ε
)

―

)

,

where Ω is an open bounded domain in

R

N

,

N
⩾
5

, and

B
(

ξ
0

,
ε
)

is a ball centered at ξ
0 with radius ɛ, ɛ is a small positive parameter. We obtain the existence of solutions for problem (0.1), which is an arbitrary large number of sign-changing solutions whose profile is a superposition of bubbles with alternate sign which concentrate at the centre of the hole.
Ultrafast oscillation in a field emission-driven miniaturized gaseous diode
Authors: Chen Jiandong , Lin Chubin , Wang Huihui , Ang Lay Kee , Fu Yangyang
Published: April 2024

We report an ultrafast oscillation (up to

∼

10
4

GHz) in the early stage of field emission-driven microdischarges. Spatiotemporal behaviors of electron density, space charge density, and electric field, exhibiting high-frequency oscillations, are demonstrated based on first-principle particle-in-cell/Monte Carlo collision simulations. Intermittent electron emission fluxes are identified from the electron phase space distributions whereas the ions are rather non-oscillatory in the transient timescale. The mechanisms of oscillation with growing amplitude are found to be related to the rapid modification of the field emission current affected by the space charge electric field, which is also accompanied by the fast response of the electron transport and ionization in a dynamic double-layer sheath. Further, a transport equation for emission current is solved to estimate the oscillation frequency, which agrees well with the simulation results. This study provides a more precise understanding of the formation of the field emission-driven microdischarge, which informs the design and optimization of miniaturized gaseous electronic devices.
A comprehensive review on potential of diffusion length enhancement to upraise perovskite solar cell performance
Authors: Bagade Sonal Santosh , Patel Piyush K
Published: April 2024

To achieve efficient solar cells, an in-depth review on significance of diffusion length enhancement is presented in this research work. We have focused on globally-adopted strategy of increasing diffusion length. The experimental pathways followed by various researchers to realize this strategy are deeply explored in this paper. The total of nine key-parameters that control and facilitate diffusion length enhancement are identified. Moreover, total of four parameters which are primarily influenced by diffusion length enhancement are listed. The underlying cause-&-effect mechanism pertaining to each parameter is discussed in-depth in this article. Furthermore, the comparison is performed between impact of electron and hole diffusion length enhancement on the device performance. The way to potentially implement this study for appropriate absorber layer selection is presented. Finally, a comparative study is performed on extent of influence of diffusion length enhancement technique to that of the band-offset optimization technique to achieve higher device performance. This rigorous analysis leads to discovery of the fact that diffusion length enhancement raises solar cell efficiency seven times as compared to that obtained by band offset optimization. Hence, significance of diffusion length enhancement for the pinnacle performance of solar cell is vividly revealed in this paper.
Improved performance of inorganic CsPbI3 perovskite solar cells with WO3/C60 UTL bilayer as an ETL structure: a computational study
Authors: Mohandes Aminreza , Moradi Mahmood
Published: April 2024

CsPbI3, also known as cesium lead iodide, has garnered significant attention as a potential absorber in perovskite solar cells (PSCs). CsPbI3-PSCs have not matched the high performance of hybrid PSCs. This study aimed to identify an effective combination of charge transport layers. Six-hole transporting layers (HTLs) including Spiro-OMeTAD, Cu2O, CuO, CuAlO2, CuSbS2, and SrCu2O2, as well as five electron transporting layers (ETLs) such as TiO2, WO3, ZnO, IGZO, and CdZnS, were tested separately in 30 PSCs. The findings of this research indicate that CuAlO2 as the HTL and WO3 as the ETL that are the most appropriate materials among the options examined, so we use FTO/WO3/CsPbI3/CuAlO2/Au as a required PSC. In this research, we used SCAPS (Solar Cell Capacitance Simulator)−1D device modeling to investigate the bilayer ETL of inorganic CsPbI3-PSC and discover the methods to improve their efficiency. In planar PSCs, optimizing electron–hole pair extraction and recombination at the ETL/perovskite interface is crucial for achieving high performance. The key concept is to enhance the WO3/perovskite interface properties by adding a 5 nm ultra-thin layer (UTL) of C60. The bilayer structure WO3/C60 was found to have the advantage of high electron extraction and low interfacial recombination, primarily due to more effective energy level alignment and defect passivation. To achieve the superior efficiency of PSC, various factors such as defect and doping densities in all layers, the energy level alteration of ETL and HTL, interface defect densities on both ETL and HTL sides, back metal contact, operating temperature, and parasitic resistances were optimized. After optimizing these parameters, the efficiency of the system containing WO3/C60 bilayer ETL was found to be 29.39%. The current work proposes a straightforward and promising method to create photovoltaic devices, especially for many types of perovskites, with desirable charge transport layers and recombination properties.
Frequency selective low-loss transmission in negative curvature hollow-core fibers
Authors: Gamble Jacob , Ordu Mustafa , Akosman Ahmet E
Published: April 2024

A new low-loss negative curvature fiber design, named as the pole-anchored nested tubular negative curvature fiber, which exhibits frequency selective capabilities in the near-infrared region is proposed. This unique approach involves the addition of nested tubular elements anchored by vertical poles, which serve as an in-fiber resonator. The resulting frequency selective resonant loss dips exhibit high finesse and relative loss modulation depth. The concept of frequency selectivity in negative curvature fibers introduces unique possibilities for future applications of hollow-core structures.
Self-calibrating BAO measurements in the presence of small displacement interlopers
Authors: Nguyen Alan B.H. , Massara Elena , Percival Will J.
Published: April 2024

Baryon Acoustic Oscillation (BAO) observations offer a robust method for measuring cosmological expansion. However, the BAO signal in a sample of galaxies can be diluted and shifted by interlopers — galaxies that have been assigned the wrong redshifts. Because of the slitless spectroscopic method adopted by the Roman and Euclid space telescopes, the galaxy samples resulting from single line detections will have relatively high fractions of interloper galaxies. Interlopers with a small displacement between true and false redshift have the strongest effect on the measured clustering. In order to model the BAO signal, the fraction of such interlopers and their clustering need to be accurately known. We introduce a new method to self-calibrate these quantities by shifting the contaminated sample towards or away from us along the line of sight by the interloper offset, and measuring the cross-correlations between these shifted samples. The contributions from the different components are shifted in scale in this cross-correlation compared to the auto-correlation of the contaminated sample, enabling the decomposition and extraction of the component terms. We demonstrate the application of the method using numerical simulations and show that an unbiased BAO measurement can be extracted. Unlike previous attempts to model the effects of contaminants, self-calibration allows us to make fewer assumptions about the form of the contaminants such as their bias.
Study on the as-cast microstructure and mechanical properties of 35CrMo steel based on electric field control
Authors: Xiao Qinghe , Zhou Ye , Miao Xincheng , Liu Siyao , Zhao Jiyu , Guan Rui , Ai Xingang , Li Shengli
Published: April 2024

Herein, the effect of current on the solidification microstructure and properties of 35CrMo structural steel has been studied. The effect of an electric field on the solidification structure of an ingot was investigated by immersing two parallel electrodes into the free surface of molten steel. Using the interaction between the current and melt as well as the Lorentz force generated by its own induced magnetic field, the whole region of the melt was covered with an eddy current. The numerical simulation of the ingot solidification process has been carried out and its influence on the inner flow field during the ingot solidification control process discussed. The results showed that an applied electric field caused turbulence inside the ingot, which drove the molten alloys to rotate and stir, refined the solidification structure, reduced the solidification defects, such as shrinkage cavity and segregation, and increased from 549.9 MPa at the top edge of the ingot and 411.4 MPa at the middle edge to 560.2 and 510.2 MPa, respectively. In addition, the electric field made the hardness and strength of each part of the ingot more uniform and improved the quality of its rigidity for the steel production process.
Study on fatigue crack growth property of abrasive waterjet peened aluminum alloy
Authors: Wang Hui , Lv Zhe , Cui Huanyong , Hou Rongguo , Liu Yuanjian
Published: April 2024

Abrasive waterjet peening is a favorable surface treatment method for improving the fatigue resistance of metal materials. An insight into the fatigue crack growth properties of AWJ peened specimens is meaningful for obtaining better strengthening performance. In present work, a numerical model of AWJ peening was established and experimentally validated for investigating the fatigue crack growth characteristics of Aluminum specimens. The effect of peening and loading conditions on the fatigue performance was also analyzed. The results indicated that the stress intensity factor at the peened region was enhanced and the crack propagation was significantly inhibited by the compressive residual stress. The influence of compressive residual stress on the effective stress factor range is greater under lower external load and higher loading ratio. The fatigue life for reaching the crack length of 40 mm is increased by 37%, 60% and 98% after peening by using the intensity of 0.6 mmA, 0.8 mmA and 1 mmA, respectively.
Mechanical characteristics of hoisting construction of segmental cantilever assembled box girder bridge
Authors: Cheng Xuansheng , Sun Yue , Hong Junliang
Published: April 2024

In order to study the safety of the segmental box girder in the hoisting process, this paper designed the construction method of the gantry crane hoisting segmental box girder in combination with the actual project. By establishing a mathematical model, the mechanical properties of the segmental box girder under two different hoisting schemes were analyzed. Under different load conditions, the lifting analyses, translation analyses and descending analyses of the box girder were carried out respectively, and the deflection and stress corresponding to the box girder were obtained. Considering the displacement and stress results of the box girder under the two hoisting schemes, it was concluded that the hoisting construction of the segmental box girder should give priority to the second hoisting scheme. That is, the hoisting holes were opened at the flange position of the roof. Provide feasible technical support for future construction.