bluuebunny/crossref_metadata_2025 huggingface dataset:
A Single-Center Retrospective Cohort Study of Genotype–Phenotype Correlation of Osteogenesis Imperfecta in UAE
Authors: Zubaidi Abdulqader Al , Hassani Noura Al , Almazrouei Raya , AlShamsi Aisha
Published: September 2024

Background Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous group of inherited connective tissue disorders characterized by skeletal fragility. Patients with OI suffer recurrent fractures, limb deformities, and kyphoscoliosis. Multiple extraskeletal manifestations might also be present. Autosomal dominant variants in the COL1A1 or COL1A2 genes account for approximately 90% of cases.

Objective The aim of the study was to describe the variant spectrum and genotype–phenotype correlations in patients with OI seen in Tawam Hospital in the UAE.

Methods The authors conducted a retrospective chart review for all patients with OI assessed by geneticists at Tawam Hospital from January 2010 to December 2021. They retrieved each patient's baseline characteristics, detailed history and physical examination, laboratory, imaging, and genetic results.

Results A total of 40 patients with OI were found and included in this study. The majority (80%) were Emirati, and 57.5% were females. Consanguinity was documented in 24.3%. Thirty-seven patients (92.5%) had positive molecular testing; 28 patients (75.7%) had an autosomal dominant inheritance, and 9 patients (24.3%) had an autosomal recessive inheritance. The majority had missense variants. Four variants were novel. A high prevalence of pathogenic variants in the COL1A1 gene (57%) was found. Patients with variants in the LEPRE1 gene had early and severe phenotypes, while patients with variants in the TMEM38B gene had variable presentations. The majority of patients (85%) had skeletal phenotypes: fractures, bone deformity, scoliosis, and osteopenia. Extraskeletal phenotypes included blue sclera, dentinogenesis imperfecta, hearing loss, and dysmorphic features.

Conclusion This study reports the genotype–phenotype correlation of OI patients from the UAE. A high prevalence of pathogenic variants in the COL1A1 gene with OI type IV phenotype was found. Further multicenter more extensive studies are recommended.
Two-plasmon-decay instability in the non-eigenmode regime in laser–plasma interaction
Authors: Wu Charles F. , Zhao Yao , Ma Hang-Hang , Jiang Xu-Yan , Li Xiao-Feng , Weng Su-Ming , Chen Min , Sheng Zheng-Ming
Published: September 2024

It is shown theoretically that the two-plasmon-decay instability (TPD) in laser–plasma interaction can be excited in the non-eigenmode regime, where the plasma density is larger than the quarter critical density. This appears when the laser amplitude is larger than a certain threshold value, which is found to increase with the plasma density. In this regime, the excited electrostatic modes have a constant frequency around half of the incident light frequency. The theoretical model is validated by particle-in-cell simulations. The simulation results show that the non-eigenmode TPD has a higher threshold amplitude for the pump laser than the non-eigenmode stimulated Raman scattering (SRS) excited in the plasma above the quarter critical density. In inhomogeneous plasma, competition between non-eigenmode TPD and non-eigenmode SRS occurs since the excitation of the former is normally accompanied by the latter.
The effect of feed mechanisms on the structural design of flexible antennas, and research on their material processing and applications
Authors: Nan Xueli , Qin Bolin , Xu Zhikuan , Jia Qikun , Hao Jinjin , Cao Xinxin , Mei Shixuan , Wang Xin , Kang Tongtong , Zhang Jiale , Bai Tingting
Published: September 2024

Flexible antennas are widely used in mobile communications, the Internet of Things, personalized medicine, aerospace, and military technologies due to their superior performance in terms of adaptability, impact resistance, high degree of freedom, miniaturization of structures, and cost-effectiveness. With excellent flexibility and portability, these antennas are now being integrated into paper, textiles, and even the human body to withstand the various mechanical stresses of daily life without compromising their performance. The purpose of this paper is to provide a comprehensive overview of the basic principles and current development of flexible antennas, systematically analyze the key performance factors of flexible antennas, such as structure, process, material, and application environment, and then discuss in detail the design structure, material selection, preparation process, and corresponding experimental validation of flexible antennas. Flexible antenna design in mobile communication, wearable devices, biomedical technology, and other fields in recent years has been emphasized. Finally, the development status of flexible antenna technology is summarized, and its future development trend and research direction are proposed.
Leakage current in GaN-on-GaN vertical GaN SBDs grown by HVPE on native GaN substrates
Authors: Jin Weiyi , Zhang Yumin , Xia Songyuan , Zhu Qizhi , Sun Yuanhang , Yi Juemin , Wang Jianfeng , Xu Ke
Published: September 2024

This study investigates leakage mechanisms in vertical GaN-on-GaN Schottky barrier diodes (SBDs) and demonstrates effective mitigation strategies. The fabricated devices exhibit low reverse leakage current (1 × 10−5 A/cm2 at −200 V) and a high Ion/Ioff ratio (∼1010), surpassing the performance of GaN SBDs on foreign substrates. We elucidate dominant leakage mechanisms—thermionic emission, Poole–Frenkel emission, and variable-range hopping—and their evolution with temperature and bias. Optimized fabrication processes, including defect etching and a novel dual-layer passivation technique, achieve over a 1000-fold reduction in leakage current.
Highly tunable skyrmion-like polar nanodomains for high-density ferroelectric hard disks
Authors: Chen Hongying , Yang Wenda , Li Cheng , Jiao Peijie , Liu Zhiyu , Lin Chuanjie , Chen Yaoyao , Tian Guo , Deng Yu , Nie Yuefeng , Wu Yongjun , Liu Jun-Ming , Hong Zijian , Gao Xingsen , Wu Di
Published: September 2024

Emerging topological polar domains have a wide range of potential applications in electronic devices. It is critical to accurately manipulate these topological domains by electrical fields and explore their exotic properties for making more energy-efficient high-density non-volatile memories. Herein, we demonstrate that skyrmion-like polar nanodomains appear at room temperature in SrTiO3/PbTiO3 bilayer heterostructures by balancing the elastic and electrostatic energies via varying the SrTiO3 capping layer thickness. These polar nanodomains, stable at room temperature, can be electrically written, erased, and rewritten into the bilayer by applying an appropriate bias on the conductive tip of an atomic force microscope. The lateral size and location of these polar nanodomains can be precisely controlled. Moreover, ring-shaped conductive domain walls are observed around these polar nanodomains, with on/off ratios of more than two orders of magnitude with respect to the ferroelectric background. Based on these characteristics, the polar nanodomains can be created, erased, and probed electrically, suggesting applications for high-density ferroelectric hard disks.
High-yield implosion modeling using the Frustraum: Assessing and controlling the formation of polar jets and enhancing implosion performance with applied magnetization
Authors: Ho D. D.-M. , Amendt P. A. , Baker K. L. , Landen O. L. , Lindl J. D. , Marinak M. M. , Sio H. , Velikovich A. L. , Zimmerman G. B. , Kritcher A. L. , Dewald E. L. , Mariscal D. A. , Salmonson J. D. , Weber C. R.
Published: September 2024

Frustraums have a higher laser-to-capsule x-ray radiation coupling efficiency and can accommodate a large capsule, thus potentially generating a higher yield with less laser energy than cylindrical Hohlraums for a given Hohlraum volume [Amendt et al., Phys. Plasmas 26, 082707 (2019]. Frustraums are expected to have less m = 4 azimuthal asymmetries arising from the intrinsic inner-laser-beam geometry on the National Ignition Facility. An experimental campaign at Lawrence Livermore National Laboratory to demonstrate the high-coupling efficiency and radiation symmetry tuning of the Frustraum has been under way since 2021. Simulations benchmarked against experimental data show that implosions using Frustraums can achieve more yield with higher ignition margins than cylindrical Hohlraums using the same laser energy. Hydrodynamic jets in capsules along the Hohlraum axis, driven by radiation-flux asymmetries in a Hohlraum with a gold liner on a depleted uranium (DU) wall, are present around stagnation, and these “polar” jets can cause severe yield degradation. The early-time Legendre mode P4<0 radiation-flux asymmetry is a leading cause of these jets, which can be reduced by using an unlined DU Hohlraum because the shape of the shell is predicted to be more prolate. Magnetization can increase the implosion robustness and reduce the required hotspot ρR for ignition; therefore, magnetizing the Frustraum can maintain the same yield while reducing the required laser energy or increase the yield using the same laser energy—all under the constraint that the ignition margin is preserved. Reducing polar jets is particularly important for magnetized implosions because of the intrinsic toroidal hotspot ion temperature topology.
Data-driven prediction of scaling and ignition of inertial confinement fusion experiments
Authors: Gaffney Jim A. , Humbird Kelli , Kritcher Andrea , Kruse Michael , Kur Eugene , Kustowski Bogdan , Nora Ryan , Spears Brian
Published: September 2024

Recent advances in inertial confinement fusion (ICF) at the National Ignition Facility (NIF), including ignition and energy gain, are enabled by a close coupling between experiments and high-fidelity simulations. Neither simulations nor experiments can fully constrain the behavior of ICF implosions on their own, meaning pre- and postshot simulation studies must incorporate experimental data to be reliable. Linking past data with simulations to make predictions for upcoming designs and quantifying the uncertainty in those predictions has been an ongoing challenge in ICF research. We have developed a data-driven approach to prediction and uncertainty quantification that combines large ensembles of simulations with Bayesian inference and deep learning. The approach builds a predictive model for the statistical distribution of key performance parameters, which is jointly informed by past experiments and physics simulations. The prediction distribution captures the impact of experimental uncertainty, expert priors, design changes, and shot-to-shot variations. We have used this new capability to predict a 10× increase in ignition probability between Hybrid-E shots driven with 2.05 MJ compared to 1.9 MJ, and validated our predictions against subsequent experiments. We describe our new Bayesian postshot and prediction capabilities, discuss their application to NIF ignition and validate the results, and finally investigate the impact of data sparsity on our prediction results.
A new fractal model for flow-solid-chemical multi-field coupling in underground engineering
Authors: Cheng Gaojie , Liu Guannan , Hu Yuhao , Ji Ming , Wei Mingyao
Published: September 2024

The permeation diffusion behavior of chloride ions with seawater is one of the key factors causing damage to reinforced concrete structures due to seawater erosion of steel bars. This study establishes a new mathematical model for chloride ion transport in reinforced concrete structures exposed to seawater. The model captures the effect of chloride ions on underwater tunnel structures effectively and provides a valuable theoretical basis for the maintenance and safety of these structures. The proposed model uniquely incorporates the microscopic pore structure characteristics of concrete and the effects of static water pressure and porosity on chloride ion diffusion. The results show that: (1) the diffusion coefficient of chloride ions first increases rapidly, then remains basically unchanged and gradually decreases; (2) there is a non-linear positive correlation between porosity, static water pressure, and maximum corrosion thickness; and (3) the fractal dimension of pore curvature is opposite to the fractal dimension of pore size and crack length.
Modeling two-phase flows with complicated interface evolution using parallel physics-informed neural networks
Authors: Qiu Rundi , Dong Haosen , Wang Jingzhu , Fan Chun , Wang Yiwei
Published: September 2024

The physics-informed neural networks (PINNs) have shown great potential in solving a variety of high-dimensional partial differential equations (PDEs), but the complexity of a realistic problem still restricts the practical application of the PINNs for solving most complicated PDEs. In this paper, we propose a parallel framework for PINNs that is capable of modeling two-phase flows with complicated interface evolution. The proposed framework divides the problem into several simplified subproblems and solves them through training several PINNs on corresponding subdomains simultaneously. To enhance the accuracy of the parallel training framework in two-phase flow, the overlapping domain decomposition method is adopted. The optimal subnetwork sizes and partitioned method are systematically discussed, and a series of cases including a bubble rising, droplet splashing, and the Rayleigh–Taylor instability are applied for quantitative validation. The maximum relative error of quantitative values in these cases is 0.1319. Our results show that the proposed framework not only can accelerate the training procedure of PINNs, but also can capture the spatiotemporal evolution of the interface between various phases. This framework overcomes the difficulties of training PINNs to solve a forward problem in two-phase flow, and it is expected to model more realistic dynamic systems in nature.
Room-temperature photonic quantum computing in integrated silicon photonics with germanium–silicon single-photon avalanche diodes
Authors: Na Neil , Hsu Chou-Yun , Chen Erik , Soref Richard
Published: September 2024

Most, if not all, photonic quantum computing (PQC) relies upon superconducting nanowire single-photon detectors (SNSPDs) typically based on niobium nitride (NbN) operated at a temperature <4 K. This paper proposes and analyzes 300 K waveguide-integrated germanium–silicon (GeSi) single-photon avalanche diodes (SPADs) based on the recently demonstrated normal-incidence GeSi SPADs operated at room temperature, and shows that their performance is competitive against that of NbN SNSPDs in a series of metrics for PQC with a reasonable time-gating window. These GeSi SPADs become photon-number-resolving avalanche diodes (PNRADs) by deploying a spatially-multiplexed M-fold-waveguide array of M GeSi SPADs. Using on-chip waveguided spontaneous four-wave mixing sources and waveguided field-programmable interferometer mesh circuits, together with the high-metric SPADs and PNRADs, high-performance quantum computing at room temperature is predicted for this PQC architecture.
A spectroscopic analysis code for spatially resolved x-ray absorption data from the COAX platform
Authors: Čamdžić Dž. , Johns H. M. , Kozlowski P. M. , Elshafiey A. , Fontes C. J. , Byvank T. , Urbatsch T. J. , Fryer C. L. , Barnak D. H. , Feinberg E. , Perry T. S. , Schmidt D. W. , Farhi B. Y. , Love K. N. , Christiansen N. S. , Colgan J. , Coffing S. X. , Cowan J. , Goodwin L. A. , Edwards S. , Fierro F. , Wilson C. , Randolph R. B. , Donovan P. , Sedillo T. , Jorgenson J. , Morrow T. , Garcia V. A. , Sherrill M. E. , Finnegan S. , Marshall A.
Published: September 2024

Sophisticated tools such as computer vision techniques in combination with 1D lineout type analyses have been used in automating the analysis of spectral data for high energy density (HED) plasmas. Standardized automation can solve the problems posed by the complexity of HED spectra and the quantity of data. We present a spectroscopic code written for automated and streamlined analysis of spatially resolved x-ray absorption data from the COAX platform on Omega-60. COAX uses radiographs and spectroscopic diagnostics to provide shock position and density information. We also obtain the more novel spectral-derived spatial profile of the supersonic radiation flow into a low-density foam. Considerable effort has been spent modernizing our previous spectroscopic analysis method, including the development of new tools characterized by a faster runtime and minimal user input to reduce bias and a testing suite for verifying the accuracy of the various functions within the code. The new code analyzes our spectroscopic images in 1–2 min, with added uncertainty and confidence.
Fast photodiode arrays for high frequency fluctuation measurements of reconnecting flux ropes
Authors: Rood Thomas , Yadav Sonu , Bartolo Gustavo , Scime Earl
Published: September 2024

An array of compact, high-bandwidth (>200 MHz) and low-cost optical photodiodes has been developed and implemented on the PHASe MApping (PHASMA) experiment. Using purpose-built electronics, an array of 16 photodetectors was constructed and used to monitor broadband (1–5 MHz) fluctuations in light intensity emitted by flux ropes undergoing electron-only magnetic reconnection. These measurements reveal a swath of oscillatory behavior, including wave propagation inward toward the diffusion region at approximately the local electron Alfvén speed. Custom 3D-printed collection optics and mounting hardware allow quick reconfiguration of the array for radial or axial measurements. The electronics design is flexible enough to be used with other current-sourcing transducers, such as avalanche photodiodes; silicon photomultipliers; and infrared, x-ray, and UV photodiodes. A noise-rejecting electrical layout allows for low-noise operation close to pulsed plasma discharges. A 16-channel, 64-pixel tomographic array was constructed and initial reconstructions are presented.
Developing time-resolved x-ray diffraction diagnostics at the National Ignition Facility (invited)
Authors: Palmer N. E. , Benedetti L. R. , Vennari C. E. , Nyholm P. R. , Petre R. B. , Bhandarkar N. , Carpenter A. C. , Nagel S. R. , Eggert J. H. , Bradley D. K. , Mackinnon A. J. , Ping Y.
Published: September 2024

As part of a program to measure phase transition timescales in materials under dynamic compression, we have designed new x-ray imaging diagnostics to record multiple x-ray diffraction measurements during a single laser-driven experiment. Our design places several ns-gated hybrid CMOS (hCMOS) sensors within a few cm of a laser-driven target. The sensors must be protected from an extremely harsh environment, including debris, electromagnetic pulses, and unconverted laser light. Another key challenge is reducing the x-ray background relative to the faint diffraction signal. Building on the success of our predecessor (Target Diffraction In Situ), we implemented a staged approach to platform development. First, we built a demonstration diagnostic (Gated Diffraction Development Diagnostic) with two hCMOS sensors to confirm we could adequately protect them from the harsh environment and also acquire acceptable diffraction data. This allowed the team to quickly assess the risks and address the most significant challenges. We also collected scientifically useful data during development. Leveraging what we learned, we recently developed a much more ambitious instrument (Flexible Imaging Diffraction Diagnostic for Laser Experiments) that can field up to eight hCMOS sensors in a flexible geometry and participate in back-to-back shots at the National Ignition Facility (NIF). The design also allows for future iterations, such as faster hCMOS sensors and an embedded x-ray streak camera. The enhanced capabilities of the new instrument required a much more complex design, and the unexpected issues encountered on the first few shots at NIF remind us that complexity has consequences. Our progress in addressing these challenges is described herein, as is our current focus on improving data quality by reducing x-ray background and quantifying the uncertainties of our diffraction measurements.
Cryogenic temperatures promote the pressure-induced polymorphic transition in CoCrFeMnNi high entropy alloy
Authors: Hörnqvist Colliander Magnus , Haase Dörthe , Glazyrin Konstantin , Edgren Aina , Wang Pan , Guthrie Malcolm , Guo Sheng
Published: September 2024

Pressure-induced polymorphism has recently been demonstrated in several high entropy alloys. This offers a new window into the much-debated issue of phase selection and stability in these systems. Here, we examine the effect of cryogenic temperatures on the pressure-induced transition from face centered cubic to hexagonal close-packed structures of the prototype CoCrFeMnNi (Cantor) alloy. We observe a reduction in the critical pressure for the onset of the polymorphic transition as the temperature decreases, confirming the progressive stabilization of the hexagonal phase with decreasing temperature previously predicted by ab initio calculations accounting for magnetic interactions. We argue that in situ high-pressure experiments at cryogenic temperatures, which suppress time-dependent transformation triggered at higher temperatures, present a unique opportunity to significantly improve our understanding of these complex alloys.
Entropy production-based nonlinear optimal perturbation for subsonic flows around an airfoil
Authors: Taniguchi Nobutaka , Ohmichi Yuya , Suzuki Kojiro
Published: September 2024

The extraction and time evolution of optimal perturbation (OP) offers abundant physical insights in fluid dynamics. Nonlinear OP (NLOP) analysis provides an approach for obtaining the trajectory to induce the maximum changes in the flow field. In an extension into unsteady flow field, we tracked the changes of trajectory by an application of initial perturbation field in the compressible Navier–Stokes equation, and we focused on the entropy production (EP) to characterize the trajectory. We proposed entropy production-based NLOP (EP-NLOP) analysis for compressible flows and investigated the effect of evaluation function on the extracted Ops using the subsonic flow around an airfoil. Compared with the conventional disturbance energy (DE-) based NLOP (DE-NLOP) analysis, we demonstrated that the OPs with different spatial wavelength and concentration regions were successfully extracted due to the different spatial sensitivity of evaluation function. In the EP-NLOP analysis, the spatial distribution of OP extracted the larger energy dissipation upstream of the separation points for the short evaluation time. For the long evaluation time, EP-NLOP analysis extracted the transient-time evolution of interacting separation vortices, attributing the multiple wavelengths of OPs. These differences in the OPs offer promising insights into fluid dynamics.
Extensive computational fluid dynamics analysis of microchannel flow topology and friction factor in arrays of conical pin-fins
Authors: Jaseliunaite J. , Seporaitis M.
Published: September 2024

The design of integrated circuits presents an increasing challenge for engineers, who seek to identify effective methods for cooling the miniature electronic components that are becoming increasingly complex. One potential solution is the use of micro pin-fin heat sinks, which have the potential to be an effective thermal management technique. This study compares the potential thermo-hydraulic efficiency of micro heat exchangers with conical pin-fins, arranged in two alternative patterns. The flow topology was investigated using the critical points theory and Ω-criteria to gain a deeper understanding of vortical structures and flow separation. 75 variations of pin-fin arrays were simulated and analyzed. It is noteworthy that no pattern similar to bidirectional pin-fins has been studied previously. The input datasets for the simulations included pitch/height ratios ranging from 0.823 to 1.235, cone angles from 0° to 13.48°, and flow Reynolds numbers of 40–117. The numerical results show that Ω and kinetic energies can predict the onset of instabilities. The degree of conicity and the pattern affect the friction factor, typically reducing it. The conical shape and arrangement of pin-fins can also aid in stabilizing the flow. Furthermore, the dependence of the friction factor on pitch/height and Reynolds was quantified with the calculated mean relative error of 1.7%. Moreover, turbulence parameters and friction factors were used to evaluate the thermohydraulic properties, deliberately excluding heat transfer simulations. This approach allows a much wider range of geometric modifications to be investigated for the preliminary optimization of the thermal and hydraulic performance of microchannels.
Machine learning assisted mechanism modeling for gas phase electrohydrodynamic system
Authors: Chen Wen , Cai Ru-Xian , Wang Le , Yang Zhi-Zhou , Wei Ran , Yan Wei-Cheng
Published: September 2024

In this paper, a hybrid physics-data driven model for electrohydrodynamic gas system (EHDGS) was developed by combining artificial neural network (ANN) with mechanism modeling method. ANN was used to correlate the relationship between the variables (electrode distance, diameter of grounding cylinder, applied voltage, electric field gradient, etc.) in a needle-cylinder EHDGS and the initial space charge density. The results showed that the ANN model of nine neurons can well predict the initial space charge density. The coefficient of determination (R2) reaches 0.9874, and the mean absolute error is as low as 0.0067. Subsequently, a hybrid mechanism model where the initial space charge density was predicted from the ANN model was constructed to simulate the needle-cylinder EHDGS. The experiment with the needle-cylinder EHDGS was carried out. The simulation results were in good agreement with the experimental data, demonstrating the reliability of the proposed hybrid model. The electric field distribution, space charge distribution, and flow field distribution behavior of the EHDGS were then analyzed in detail. The effects of key parameters on the flow characteristics of EHDGS were systematically studied, showing that higher voltage and shorter distance give higher flow rate up to 2.5 m/s. The diameter of the cylinder also significantly influences the breakdown voltage. Three dimensionless groups were defined and their effects on spatial charge density distribution were investigated. This study provides both insights and an efficient tool for the design and optimization of EHDGS.
Flow over two inline rough cylinders in the postcritical regime
Authors: Pasam Anil , Smith Daniel Tudball , Burton David , Thompson Mark C.
Published: September 2024

This study investigates the flow behavior over roughened inline cylinders for postcritical flow, a parameter space with relatively little prior scrutiny. Two cylinders of the same relative surface roughness, ks/D=1.9×10−3, separated by a pitch (i.e., L, distance between the centers of two cylinders) between 1.175≤L/D≤10 are studied at Reynolds numbers from 3×105 to 6×105 using unsteady surface pressure measurements. As pitch ratio is increased from L/D=1.175, CD of the downstream cylinder increases sharply at (L/D)c=3.25. This critical pitch ratio (L/D)c is toward the lower end of the reported range for subcritical smooth cylinders. Asymmetric mean gap flow along with alternating reattachment is found for 1.5≤L/D<2.25 (i.e., two asymmetric modes in the gap, mode 1 and mode 2, that are the reflections of each other), and symmetric gap flow with a continuous reattachment is found for 2.25<L/D≤3. The gap flow is also symmetric for the closest pitch ratio tested of L/D=1.175. While the change in upstream cylinder drag coefficient with Reynolds number broadly follows that of an isolated cylinder, for the downstream cylinder, it is approximately independent. The critical separation is also insensitive to Reynolds number within 3×105≤Re≤6×105. Transitions between the reattachment and the co-shedding flow are predominantly continuous over the spanwise planes tested. On the other hand, alternating reattachment occurs in spanwise cells, where one sectional measurement exhibits the asymmetric mode 1 while a spanwise-adjacent section exhibits the asymmetric mode 2 or even symmetric flow. Previously reported maxima in the fluctuating lift and drag coefficients of the downstream cylinder at L/D≈2.4 at subcritical Reynolds numbers are absent in the current investigation.
Advances in textile-based microfluidics for biomolecule sensing
Authors: Milić Lazar , Zambry Nor Syafirah , Ibrahim Fatimah Binti , Petrović Bojan , Kojić Sanja , Thiha Aung , Joseph Karunan , Jamaluddin Nurul Fauzani , Stojanović Goran M.
Published: September 2024

Textile-based microfluidic biosensors represent an innovative fusion of various multidisciplinary fields, including bioelectronics, material sciences, and microfluidics. Their potential in biomedicine is significant as they leverage textiles to achieve high demands of biocompatibility with the human body and conform to the irregular surfaces of the body. In the field of microfluidics, fabric coated with hydrophobic materials serves as channels through which liquids are transferred in precise amounts to the sensing element, which in this case is a biosensor. This paper presents a condensed overview of the current developments in textile-based microfluidics and biosensors in biomedical applications over the past 20 years (2005–2024). A literature search was performed using the Scopus database. The fabrication techniques and materials used are discussed in this paper, as these will be key in various modifications and advancements in textile-based microfluidics. Furthermore, we also address the gaps in the application of textile-based microfluidic analytical devices in biomedicine and discuss the potential solutions. Advances in textile-based microfluidics are enabled by various printing and fabric manufacturing techniques, such as screen printing, embroidery, and weaving. Integration of these devices into everyday clothing holds promise for future vital sign monitoring, such as glucose, albumin, lactate, and ion levels, as well as early detection of hereditary diseases through gene detection. Although most testing currently takes place in a laboratory or controlled environment, this field is rapidly evolving and pushing the boundaries of biomedicine, improving the quality of human life.
Wire-to-two-drop plasma thruster: Experimental and numerical investigation of electroaerodynamic jet flow for micro aerial vehicle propulsion
Authors: Ahangar Mahdy , Alebrahim Narges
Published: September 2024

Conventional micro aerial vehicles (MAVs) have primarily relied on complex, flapping-wing mechanisms for propulsion, often exhibiting limitations in terms of reliability and efficiency. To overcome these challenges, this study explores the potential of electroaerodynamic (EAD) thrusters as a novel propulsion system. By accelerating air molecules through ion collisions, EAD jet flow generates thrust, offering advantages such as noiseless operation and zero emissions due to its moving-part-free design. This research presents a comprehensive experimental and numerical investigation of a wire-to-two-drop thruster configuration to elucidate its electromechanical performance, plasma flow dynamics, and EAD jet characteristics. Experimental measurements of key parameters, including current, thrust, power, and effectiveness, were correlated with numerical simulations, demonstrating excellent agreement with a maximum error below 5%. These findings align strongly with established theoretical frameworks, revealing an inverse square root relationship between effectiveness and thrust. To optimize thruster performance, optimal operating voltages were identified at approximately 8.2, 9.4, and 11.6 kV for inter-electrode gap distances of 10, 15, and 20 mm, respectively, achieving a balanced trade-off between thrust and effectiveness. Detailed numerical visualizations of the plasma flow field, including velocity distribution, jet morphology, potential distribution, and electric field lines, provided valuable insights into the thruster's operation. Building upon these insights, a proof-of-concept EAD flier was constructed and tested, incorporating a serrated emitter electrode and lightweight materials. This flier achieved a mass of 0.5 g and generated a thrust of 0.77 g at 15 kV, resulting in a thrust-to-weight ratio of 1.54 and successful liftoff. This demonstration highlights the potential of EAD propulsion for practical MAV applications.
On the role of the Froude number on flow, turbulence, and hyporheic exchange in open-channel flow through boulder arrays
Authors: Liu Yan , Tang Zhengdao , Huang Lei , Stoesser Thorsten , Fang Hongwei
Published: September 2024

In this paper, the results of numerical simulations of open-channel flow through boulder arrays at varying Froude numbers are reported. The simulations aim at clarifying the role of the Froude number on flow, turbulence, and hyporheic exchange. At low and intermediate Fr, the boulder top is above the water surface, and time-averaged streamwise flow velocity, Reynolds shear stresses, and the turbulent kinetic energy (TKE) are relatively low in the wake of boulders. Conversely, at high Fr values, the boulders are submerged, hence the flow separates at the boulder crest, creates vertical recirculation, and reattaches on the bed downstream, resulting in an area of elevated Reynolds shear stresses and TKE downstream of the boulders. Two dominant turbulence structures are observed: (i) flapping of boulder wakes with a characteristic length of 2.1 times the boulder diameter (D) at low and intermediate Fr and (ii) an upstream oriented hairpin vortex with a length scale of 1.0D at high Fr. These turbulence structures influence hyporheic exchange downstream of boulders within a limited region of x/D<2.0. In other locations, hyporheic flow is driven by downwelling flow immediately upstream of boulders with a wavelength larger than 2.9D. Finally, the normalized time-averaged hyporheic flux increases with increasing Fr, but it decreases at higher Fr values once the overtopping flow disrupts the formation of the boulder wake.
Mechanics of a marine midge water locomotion
Authors: Wu Chih-Hua , Soong Keryea , Chen Bang-Fuh
Published: September 2024

Marine midges, tiny insects with a body size of 2 mm and a weight of 0.07 dyn, provide valuable insights into advanced locomotion techniques. Found in shallow reefs at Wanlitong, Kenting National Park, Taiwan, these midges can continuously traverse seawater surfaces for over 90 min at speeds around 340 body-lengths per second. Their flight relies on two primary mechanisms: wing sculling to utilize surface tension for thrust and wing retraction to generate aerodynamic lift. This study addresses the gap in understanding how marine midges generate the lift and thrust needed for prolonged flight. We investigated their unique locomotion by conducting experiments to measure their weight, speed, and wing frequency. These measurements informed 3D computational fluid dynamics (CFD) simulations to analyze the aerodynamic forces involved. The results highlight the critical role of the ground effect, where maintaining minimal gaps of 0.08 mm between the midge trunk and 0.055 mm at the wing tips is essential for lift. Additionally, a high wing-beat frequency exceeding 300 Hz is crucial for generating sufficient lift during wing retraction. Our findings emphasize that ground effect, forward speed (>60 cm/s), and wing-beat frequency are key factors enabling marine midges to sustain flight above the sea surface. This unique adaptation for water surface locomotion not only showcases the midge's remarkable flight capabilities but also offers valuable insights for the design of micro-air vehicles (MAVs).
Soliton interaction in a two-temperature electron plasma with trapping and superthermality effects
Authors: Malik Usama H. , Ali S. , Jahangir R. , Khan Majid
Published: September 2024

Head-on collision of the two small-amplitude electron-acoustic (EA) solitons is studied in an unmagnetized collisionless plasma in the presence of superthermal (hot) trapped electrons. For this purpose, using a well-known extended Poincare–Lighthill–Kuo (PLK) method, a pair of the trapped Korteweg–de Vries (tKdV) equations is derived to investigate the soliton trajectories and phase shifts. The latter are found dependent on amplitudes of the interacting solitons, effectively altering with hot-electron superthermality and plasma parameters. Typical parameters for the electron diffusion region (EDR) and day-side auroral zone have been selected to examine the impact of hot-electron superthermality, trapping parameter, hot-to-cold electron number density ratio, and cold-to-hot electron temperature ratio on the profiles of potential excitations and phase shifts of interacting solitons. It is found that phase speed of the EA waves becomes altered by varying the κ–parameter, strongly modifying the nonlinearity and dispersive coefficients in a superthermal trapped plasma. However, particle trapping phenomenon does not affect the linear phase speed but introduces a fractional nonlinearity in the tKdV equations of two interacting solitons. The impact of the adiabatic and isothermal pressures is also highlighted to show new modifications in the propagation characteristics of two interacting solitons.
Energy performance improvement for a mixed flow pump based on advanced inlet guide vanes
Authors: Zheng Yunhao , Li Yanjun , Zhang Fan , Yuan Shouqi , Zhu Xingye
Published: September 2024

The sharp decrease in the efficiency of a mixed flow pump within over-load flow rates presents a challenge for coastal drainage pumping stations. To address this issue, two different structures of advanced inlet guide vanes (AIGV), full-adjustable (FA) and half-adjustable (HA) structures, are designed to approach a better energy performance improvement strategy. Entropy production theory is applied into transient flow field to reveal their influence mechanism on the spatial distribution of energy dissipation. The primary findings are as follows: (1) AIGVs effectively solve the sharp decrease in the energy performance of mixed-flow pumps within the over-load flow rate range, broadening its efficient operation range. (2) The decrease in the axial velocity under the effect of AIGV explains the primary fluid physics of the increased efficiency. (3) The improvement in the match between the impeller inflow angle distribution and the impeller blades structure suppresses the generation and transmission of the flow separation on the pressure side, and reduce the near-wall energy dissipation. The novel HA-AIGV obtains a better flow control effect.
Unveiling hidden dynamic correlations in CASSCF correlation energies by Hartree–Fock nodes
Authors: Šulka Martin , Šulková Katarína , Dubecký Matúš
Published: September 2024

We have recently introduced an original method for sharply partitioning the correlation energy into dynamic and non-dynamic contributions. This method is based on the node of the Hartree–Fock (HF) Slater determinant and the stochastic projector fixed-node diffusion Monte Carlo (FNDMC) method [Šulka et al., J. Chem. Theory Comput. 19, 8147 (2023)]. This approach addresses the challenge of dissecting correlation energy in quantum chemistry. Here, we present the first application of this technique to explore CASSCF correlation energy contributions in selected molecular systems such as BH, FH, F2, and H2–H2. The results show that correlation energies derived from the full-valence active space CASSCF method, often believed to describe mostly non-dynamic correlation effects, contain an extraneous, unwanted, system-dependent component that belongs to the dynamic correlation energy. The findings suggest that the new HF-node/FNDMC-based electron correlation energy decomposition method provides a useful complementary tool, enabling the detection of inherent challenges in distinguishing between dynamic and non-dynamic contributions to correlation energies within methods where precise dissection of these effects is not possible.
From disorder to order: A dynamic approach to mesophase formation in soft sphere model
Authors: Uranga Wassermann María Victoria , Soulé Ezequiel R. , Balbuena Cristian
Published: September 2024

This study explores the dynamics of self-assembly and mesophase formation through molecular dynamics simulations of hexagonal and lamellar systems using a simplified coarse-grained model. We focus on characterizing the order–disorder transitions driven by temperature variations and emphasize the often overlooked disordered regime, which serves as a precursor to periodic mesoscale ordering. Our findings not only underscore the morphological richness of the disordered regime, comparable to that of its periodic counterparts, but also reveal the presence of clustering regimes within isotropic phases, thus corroborating prior experimental and theoretical observations. By employing the dynamic correlation coefficient, this work introduces a novel approach to understanding the fundamental mechanisms of mesophase formation, providing new insights into the complex dynamics of self-assembly.
Dynamics of a falling plate at low Reynolds numbers
Authors: Sun Shuyue , Zhao Yakun , Zhang Huanyu , Tian Xinliang , Wang Peng
Published: September 2024

Free-falling of objects in fluids is universal in nature and engineering. The falling styles of the falling object are affected by the properties of both the object and the fluid. Based on the assumption that the final state of a free-falling object at low Reynolds numbers is stable and equivalent to that of a fixed object with incoming flow, we utilize the results for the fixed plate to interpolate and obtain the state of the falling plate. It is found that the plate would exhibit multiple stable falling solutions. The number of stable falling solutions is dependent on the location of the gravity center of the plate. The distribution of the multi-solution region is affected by both Archimedes number (Ar) and the density ratio (m*). The results of the actual fall of the plate do not always agree with those obtained by the static interpolation method due to the fact that the fall of the plate is a dynamic process. We simulate the falling behaviors of plates whose center of gravity is located in the multi-solution region for different initial release angles θ0. According to the falling behaviors of the plate, there are four regions that are observed and denoted in the multi-solution region: (1) single stable region; (2) bistable region; (3) single stable and fluttering region; and (4) bistable and fluttering region. The effects of Ar,m*, and the dimensionless moment of inertia I* of the plate on the distribution of the four regions are evaluated.
Fusion neutron source and array of particle detectors for nondestructive interrogation of special nuclear materials
Authors: Masuda Kai , Takahashi Yoshiyuki , Misawa Tsuyoshi , Yamakawa Norio , Scott Thomas B. , Bakr Mahmoud
Published: September 2024

Presented herein are the outcomes of an experimental test involving a pioneering portable-active interrogation system designed for the nondestructive detection of special nuclear materials (SNMs). The system relies on the threshold energy neutron analysis concept and incorporates a portable deuterium–deuterium (DD) neutron generator producing a particle intensity of 5 × 107 n/s, coupled with three arrays of tensioned metastable fluid detectors (TMFDs) to detect secondary neutrons from the fissile material. In the presence of the fissile material, prompt fission neutrons are emitted, with an average energy of approximately 2 MeV, and around 30% of these neutrons have energies above that of the DD neutron source (2.45 MeV). The detection of a statistically significant neutron population exceeding this threshold firmly indicates the presence of SNM. TMFDs exhibit high sensitivity in efficiently detecting neutrons above the threshold while adeptly discriminating against neutrons below the threshold as well as gamma rays. This unique feature allows the interrogation system to maintain a lightweight profile without necessitating substantial shielding materials. The validation experiments involved the placement of 70 or 140 g masses of U-235 within a 1 m3 inspection volume. Measurements were carried out over 30 min intervals, repeated numerous times, both with and without U-235, at a DD neutron source intensity of 8 × 105 n/sec. Experimental count rates with natural uranium (NU) are consistently above those without NU. The probability of detection (PD) and probability of false alarm (PFA) were assessed utilizing these count rates. The DD neutron source intensity and inspection time were normalized at 5 × 107 n/sec and 90 s, respectively. The results indicated a PD of approximately 74% and 98% for detecting 70 and 140 g of U-235, respectively, with a PFA of <5%. These promising outcomes align with the specified PD (>90%) and PFA (<5%) targets outlined in ANSI standards.
Adaptive momentum equation method for overcoming singularities of dispersed phases
Authors: Xiong Huajie , Wang Na , Zeng Tao , Xu Kairen , Zhou Zhihong
Published: September 2024

The singularity issue arising from the phase fraction approaching zero in multiphase flow can significantly intensify the solution difficulty and lead to nonphysical results. By employing the conservative form of momentum equations in high-phase-fraction and discontinuity regions and the phase-intensive form of momentum equations in low-phase-fraction regions, computational reliability can be assured while avoiding the singularity issue. Regarding the proposed adaptive momentum equation method, the form of momentum equations for each cell is determined by a conversion bound and a phase fraction discontinuity detector. A comparative analysis is conducted on this method and other singularity-free methods. For discontinuities of dispersed phases, an error estimation method of the conversion bound is presented through theoretical analysis. Computational results demonstrate that the discontinuity detector accurately captures discontinuities in high-phase-fraction regions while disregarding pseudo-discontinuities in low-phase-fraction regions. Compared to the conservative form corrected by the terminal velocity method, the method yields higher-quality flow fields and potentially exhibits an efficiency improvement of over 10 times. Compared to the phase-intensive form, the method benefits from the physical quantity conservation, providing higher computational reliability. When encountering discontinuities, the expected error from the error estimation method aligns well with the actual error, indicating its effectiveness. When the conversion bound is below 1/10 000 of the inlet phase fraction, the errors of the adaptive method are essentially negligible.
Grouting characteristic in rock fractures with different structural properties: Apparatus design and experimental study
Authors: Wang Xiaochen , Zhang Lianzhen , Li Zhipeng , Wang Hongtao , Li Xia
Published: September 2024

Rock fracture surfaces are normally rough, with upper and lower surfaces presenting obvious structural properties (i.e., matching or mismatching). In this paper, rock fracture was divided into shear and tensile fractures based on its mechanical origin. A test simulation system for grouting in rough fracture (tensile and shear fractures) with continuous pressure field monitoring was proposed. A series of grouting simulation tests were employed to evaluate the effect of fracture structural property, fracture surface roughness, and aperture on the characteristics of grout flow in the rough fracture. The results show that grouting pressure exhibited a trend of rapid increase followed by a slow increase with time during the grouting in the tensile and shear fractures. Grouting pressure increases with time in a smooth relationship for tensile fracture and a fluctuating upward relationship for shear fracture. The slurry pressure distribution along the penetration length exhibited a nonlinear attenuation trend. The attenuation degree of the slurry pressure was positively related to the fracture roughness and the roughness difference in the upper–lower fracture surface and negative with the fracture aperture. The potential filtration effect during the grouting process is an important factor affecting the grouting behavior in the rough fracture.