bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow patterns and vortex formation mechanisms inside a human nasal cavity
Authors: Niegodajew Paweł
Published: February 2025

Nasal airflow studies continue to face challenges due to the intricate nature of airflow and the variability in nasal cavity geometries. While significant advances have been made, much of the existing research, including studies employing Large Eddy Simulation (LES), focuses primarily on velocity magnitude fields. However, understanding nasal airflow dynamics requires examining individual velocity components, enabling a more detailed investigation of directional flow behavior and localized phenomena such as vortices. In this study, a high-accuracy LES method was used to investigate airflow patterns in the main nasal passage and around the turbinates, with particular emphasis on turbulence in these regions. The analysis revealed several previously undocumented vortices, including counter-rotating vortices in the central region of the main nasal passage caused by the interaction between the incoming airflow and the middle turbinate bone. Additionally, larger recirculation zones were identified near the cavity floor in the inferior meatus and within the lateral wall of the middle meatus. Velocity fluctuations were highest in the central nasal passage, with elevated levels also observed in the inferior and posterior sections, whereas the vestibule region exhibited high velocities but low fluctuations, indicating stable flow conditions. While this study primarily focuses on the dynamics of nasal airflow, it also attempts to explore the hypothetical implications of velocity fluctuations and vortex formation on particle transport and surgical practices. These aspects remain speculative but suggest that such dynamics could have important effects on both therapeutic strategies and surgical interventions, thus guiding future studies in these areas.
Damage characteristics of shale with different bedding inclinations under high-pressure water jet impact after thermal treatment
Authors: Ge Zhaolong , Cui Yuhuai , Deng Qinglin , Shangguan Jianming , Yao Zhi , Li Zhongtan , Liu Lei , Ge Binbin
Published: February 2025

Water jet-assisted rock breaking is a conventional method for shale gas extraction. However, the complex conditions of deep shale reservoirs, including elevated temperatures and intricate stratification, obscure the rock-breaking mechanisms of jets. Therefore, this study conducted high-pressure water jet impact experiments on shale with five bedding angles (0°, 30°, 45°, 60°, and 90°) and four temperatures (room temperature, 100, 150, and 200 °C). Computed tomography (CT) and three-dimensional reconstruction techniques were used to analyze the damage characteristics. Results indicate that increased temperature significantly enhances rock-breaking efficiency. The crack volume fraction at 200 °C increased by 146.44 times compared to 25 °C. The new crack area exhibited a sharp increase from 100 to 150 °C compared to the slow increase rate before and after this temperature range, indicating the presence of a threshold temperature for effective fragmentation by jet impact. Damage showed significant anisotropy, with crack depth increasing with bedding angle and a through crack emerged at 90°, while the new crack area peaked at 45°. The jet rock-breaking efficiency index (JREI) was introduced which integrates crack volume, area, and depth to characterize the fragmentation efficiency at different temperatures and bedding conditions. These findings could provide a theoretical basis for enhancing the fragmentation of deep shale.
Interaction and jet behavior of synchronous and asynchronous double bubbles
Authors: Liu Zhibo , Wang Zhikai , Zhang Xiubin , Zhao Kun , Yao Xiongliang
Published: February 2025

The interaction between multiple bubbles is essential in various fields, including underwater explosions, cavitation, and medical imaging. Topics such as bubble bursting and jet formation have garnered significant research interest. This study integrates electric spark experiments and numerical simulations to analyze the behavior of double-array bubbles, with variations in their spacing and proximity to boundaries. It investigates how spatial parameters influence bubble cycles, maximum radius, and jet formation, establishing a clear relationship between jet direction and explosion distance. Results indicate that timing primarily affects bubble dynamics by altering the direction of the Bjerknes force. Additionally, timing influences jet velocity, while bubble spacing (γb) and depth (γf) regulate the maximum radius and pulsation cycle. The pulsation cycle (T) decreases with greater γb, stabilizing under free-field conditions. An inflection occurs near γf=2.0, with further reductions as distance increases. Near the free surface, γf has minimal effect on the cycle, which decreases slightly (by approximately 8%). These findings have significant implications for applications in medicine, underwater explosions, and structural protection.
The Manhattan exciton size: A physically tractable delocalization measure
Authors: Jansen T. L. C.
Published: February 2025

Delocalized excitations, denoted excitons, play an important role in many systems in chemical physics. The characterization of their extent of delocalization is a crucial element in understanding these quasiparticles. In this paper, I will revisit the most common delocalization measures applied to Frenkel-type excitons. Based on this analysis, I propose to use a so-far ignored measure. The key advantage of this measure, which I will denote as the Manhattan exciton size, is that it directly connects with the oscillator strength of the excitons. It provides a strict upper bound on the oscillator strength of any given exciton for linear aggregates. Finally, I demonstrate that this exciton delocalization measure is more sensible for analyzing super-radiant states compared to, for example, the most commonly applied measure, i.e., the (inverse) participation ratio. However, these two measures together provide insight into the degree of exciton confinement.
Blast tube design: How shape and size influence the resultant shock wave
Authors: Bauer R. L. , Johnson C. E.
Published: February 2025

Shock tubes and tunnels are often used in research settings as a way of producing high pressure shock waves in a smaller footprint or without the use of explosives. However, there is no standard geometric design across laboratories. Peak pressure is a significant parameter for characterizing a shock wave. However, different tube configurations could also affect parameters such as impulse and duration, yet no research has investigated how the scale of the tube affects the overall waveform shape. To understand the implications of shock tube design, tubes with a constant length to diameter ratio were evaluated to determine how tube scaling affects the shock parameters. Larger tubes with a greater length and diameter produced more intense, shorter-duration shocks, resulting in higher pressure/duration ratios and up to a 20.9% reduction in impulse. Analysis of the pressure vs time profiles showed that square tubes have a more consistent self-similar relationship in peak pressure. Square tubes also exhibit a more pronounced negative phase than circle tubes of the same length-to-diameter (L/D) ratio. Increasing the diameter of constant length tubes from 0.5 to 1 cm increases the incident pressure by 90.94%, although this also leads to shorter shock wave durations. Conversely, increasing the length of constant diameter tubes results in a 2.4% reduction in incident pressure. These findings show that while peak pressure is important, the duration and impulse of the shock wave are crucial for determining the overall energy applied.
Wave scattering by a coaxial pair of surface-piercing porous cylinder and bottomless thick annular cylinder
Authors: Saha Sunanda , Barman Koushik Kanti , Bora Swaroop Nandan , Tsai Chia-Cheng
Published: February 2025

In this work, we consider a mathematical model for wave scattering by two coaxial cylinders: a surface-piercing porous cylinder and a bottomless thick annular cylinder. Within the framework of linear water wave theory, the resulting boundary value problem is solved using the matched eigenfunction expansion method. Then, a numerical experiment is performed to examine the wave scattering of the porous hollow cylinder for two configurations: (i) the thick annular cylinder attached to the porous cylinder, with the gap between the porous and thick cylinder set to zero (Model-I), and (ii) the porous cylinder coupled with a bottom-mounted cylindrical trench, with the gap between the thick cylinder and the ocean floor set to zero (Model-II). A critical analysis of the numerical results reveals that, for Model-I, the width of the annular plate plays a more significant role in reducing wave impact on the porous cylinder than its thickness. Furthermore, for Model-II, it is observed that the thickness of the bottom trench significantly influences the vertical forces acting on the porous cylinder.
A process-based formula for sheet flow transport induced by combined wave-current action
Authors: Liu Yuewei , Chen Songgui , Hu Xin , Zheng Jingyun , Chen Jian , Chen Xin
Published: February 2025

A process-based formula for sheet flow transport has garnered significant attention in ocean engineering due to the necessity of topographic predictions. The process-based formula, applicable to a mobile seabed, is derived through integrating concentration and velocity profiles under the condition of asymmetric wave and current. The concentration profile accounts for the effects of acceleration and phase lag, adhering to the classical exponential law based on mass conservation principles. Conversely, the velocity profile comprises two interacting components influenced by asymmetric oscillatory wave force and current force. The formula encompasses a fundamental component that yields the classical 3/2 power law in terms of the Shields parameter, similar to traditional formulas, along with parameters related to wave boundary layer thickness. Given the limited understanding of the significance of wave shape and current, the formula is segmented into a part pertaining to wave force and another part pertaining to current force, thereby highlighting their respective importance according to different wave shapes. The instantaneous sheet flow transport is examined as a power function of velocity, incorporating phase lag, current, and wave shape. Overall, the proposed formula demonstrates satisfactory performance in both instantaneous sediment flux and net transport rate, which are the combined effects of acceleration, phase lag, wave (boundary layer) asymmetry, and wave–current interaction.
Semi-open impeller structural parameters optimization on hydraulic performance for a sanitary centrifugal pump
Authors: Chen Jia , Wang Hongyu , Pei Ji , Wang Wenjie , Gan Xingcheng , Wang Zhenhan
Published: February 2025

Sanitary centrifugal pumps, which are widely used in industrial production and account for a significant share of global electric motor energy, suffer from reduced efficiency and stability due to hydraulic losses caused by the tip clearance with semi-open impeller. Improving the performance of these pumps is therefore of great importance. This study optimizes the structural parameters of semi-open impellers for a sanitary centrifugal pump to enhance pump efficiency and reduce energy losses. Five key impeller structural parameters are evaluated and a sample database is generated using the Optimal Latin Hypercube Sampling method. The performance improvement is carried out using a Response Surface Methodology approximation model combined with the Non-dominated Sorting Genetic Algorithm II. Analysis of the optimized pump reveals a 2.04% increase in efficiency and a 1.81 m improvement in head compared to the original model. In the optimized scheme, a noticeable reduction in the areas affected by flow separation and vortex formation is identified and the high-entropy production rate area in flow channel is significantly reduced with smaller high-vorticity regions. Furthermore, a novel front cover structure is developed, revealing optimal performance at a 1/5 coverage ratio, resulting in a 6.2% efficiency gain and a 1.87 m head improvement. These findings offer valuable insights and effective strategies for enhancing the performance of sanitary centrifugal pumps while minimizing energy losses.
Field Anaesthesia for Platypuses: a proven method and the case for non-veterinarian accreditation pathways
Authors: Bino Gilad , Hawke Tahneal
Published: February 2025

This communication details the implementation of field-based anaesthesia for platypuses, applied by non-veterinarians to over 500 individuals across 9 years, with a focus on enhancing animal welfare while enabling the collection of critical scientific data. By utilising portable anaesthetic machines and tailored protocols, safe handling and minimising stress during procedures such as tagging, sample collection, and minor surgeries are ensured. Given the impracticality and high costs of having veterinarians in the field along with researchers, we advocate for accreditation pathways to empower ecologists to independently perform these important procedures, thereby improving the efficiency and sustainability of wildlife research.
HMCN1 variants aggravate epidermolysis bullosa simplex phenotype
Authors: Bergson Shir , Sarig Ofer , Giladi Moshe , Mohamad Janan , Mogezel-Salem Mariana , Smorodinsky-Atias Karina , Sade Ofir , Manori Bar , Assaf Sari , Malovitski Kiril , Feller Yarden , Pavlovsky Mor , Hainzl Stefan , Kocher Thomas , Hummel Julia I. , Eretz Kdosha Noy , Khair Lubna Gazi , Zauner Roland , Pinon Hofbauer Josefina , Shalom-Feuerstein Ruby , Wally Verena , Koller Ulrich , Samuelov Liat , Haitin Yoni , Ashery Uri , Rubinstein Rotem , Sprecher Eli
Published: February 2025

Epidermolysis bullosa simplex (EBS) refers to a heterogeneous group of inherited skin disorders characterized by blister formation within the basal cell layer. The disease is characterized by marked variations in phenotype severity, suggesting co-inheritance of genetic modifiers. We identified three deleterious variants in HMCN1 that co-segregated with a more severe phenotype in a group of 20 individuals with EBS caused by mutations in KRT14, encoding keratin 14 (K14). HMCN1 codes for hemicentin-1. Protein modeling, molecular dynamics simulations, and functional experiments showed that all three HMCN1 variants disrupt protein stability. Hemicentin-1 was found to be expressed in human skin above the BMZ. Using yeast-2-hybrid, co-immunoprecipitation, and proximity ligation assays, we found that hemicentin-1 binds K14. Three-dimensional skin equivalents grown from hemicentin-1–deficient cells were found to spontaneously develop subepidermal blisters, and HMCN1 downregulation was found to reduce keratin intermediate filament formation. In conclusion, hemicentin-1 binds K14 and contributes to BMZ stability, which explains the fact that deleterious HMCN1 variants co-segregate with a more severe phenotype in KRT14-associated EBS.
Fractional entropy of the Brown-Kuchař dust in fractional anti-de Sitter quantum gravity
Authors: da Silva Junior Pedro Felix , Jalalzadeh Shahram , Moradpour Hooman
Published: February 2025

This study derives the mass spectrum and entropy of the Brown--Kucha\v{r} dust in anti-de Sitter (AdS) spacetime using the fractional Wheeler--DeWitt (WDW) equation. The generalized fractional WDW equation is formulated using a fractional quantization map, demonstrating a correlation between the fractal mass dimension of the Brown--Kucha\v{r} dust and Lévy's fractional parameter $\alpha$ of the Riesz fractional quantum operator. These findings may provide new insights into the ramifications of the fractal behavior of cosmic structures in quantum cosmology and quantum gravity.
Study of switching behaviour of g3 based gas mixtures
Authors: Gortschakow Sergey , Uhrlandt Dirk , Kloc Petr , Aubrecht Vladimir , Coufal Oldřich , Robin-Jouan Philippe , de Holanda Sousa Renan
Published: February 2025

Ten years after its invention remains g3 - mixture of C4F7N, CO2 and O2 - most promising candidate for substitution of SF6 as insulating and switching gas. Extension and optimisation of g3 applications at high-voltage level, especially in circuit breakers requires the knowledge of properties and dynamics of arc discharge in this gas. The features of the arc plasma can be obtained from appropriate MHD simulations. To predict the arc behaviour a consistent set of thermo-physical and radiation data is necessary. A corresponding database is calculated for the case of local thermodynamic equilibrium and covers the temperature range 250 – 40000 K, pressure range 0.01 – 150 bar and various contents of C4F7N, O2 and PTFE. The contribution presents examples of plasma composition, thermo-physical and radiation properties for g3-based mixtures. An example of simulation results for a g3-filled high-voltage circuit breaker is presented and analysed. Predicted arc voltage and pressure build-up in selected volumes are compared with available experimental data. Furthermore, to explore the differences in switching behaviour between g3 and SF6, the simulations for this two gases at the same operation conditions were performed. The space- and time-dependent temperature and pressure profiles are presented and discussed.
Comparative analysis of measured and calculated radiation intensities in polymer ablated arcs
Authors: Nakano Yusuke , Tanaka Yasunori , Ishijima Tatsuo
Published: February 2025

The accurate prediction of radiation intensities in polymer-ablated arcs is crucial for optimizing the design and performance of electrical devices, such as circuit breakers, which rely on polymer ablation for arc control. In this study, both experimental measurements and numerical simulations were conducted to evaluate the radiation intensities of polymer-ablated arcs using a one-side flow outlet model. The experiment focused on light intensity profiles, while the numerical simulations accounted for the distribution of radiation coefficients derived from temperature and mass fraction of vaporized polymers. To accurately capture the arc behavior, the radiation coefficient was calculated considering both molecular and atomic spectra, with particular attention to the C2 Swan bands and Hα/Hβ atomic lines. The model effectively reproduced the experimentally measured light intensity distributions for different polymers—PA6, POM, and PTFE—despite the complexity of the radiative transfer calculations. Significant variations in radiation intensity between the polymers were attributed to differences in molecular composition and ablation characteristics. This study demonstrates that even a simplified approach to calculating radiation coefficients, using mean absorption coefficients and axisymmetric assumptions, provides results in strong agreement with experimental data. The findings highlight the essential role of molecular spectra in predicting and diagnosing polymer-contaminated arc characteristics, such as plasma temperature and polymer vapor distributions. Comparison between experimental measurements of light intensity and the calculated intensity distributions enables the accurate estimation of number density distributions of each of species in the arc plasmas, significantly advancing the understanding of polymer-vapor contaminated arcs.
Reconstruction of admittivity distribution without phase measurements in multi-frequency electrical impedance tomography (MFEIT)
Authors: Kuusela Petri , Pourghaz Moe , Seppanen Aku
Published: February 2025

Electrical impedance tomography (EIT) is an imaging modality based on applying electrical currents into the target object. Traditionally, both magnitude and phase of electric potential measured on the target surface are required to reconstruct the admittivity, i.e. conductivity and permittivity, inside the target. However, measuring the phase of potential requires more advanced EIT system than that used in amplitude data-based electrical resistance tomography (ERT). In this article, we propose a novel EIT method, amplitude-based multi frequency EIT (AMFEIT), that reconstructs admittivity using only amplitude data. Therefore, AMFEIT can be used with devices that do not provide the phase data. The performance of AMFEIT is compared to that of traditional single frequency EIT using numerical and experimental tests. In simulations, the effects of certain modelling errors and choice of frequencies on the reconstruction quality are studied. In the experimental setup, several targets inside a water tank are imaged. Both the numerical and experimental tests support the feasibility of AMFEIT for reconstructing admittivity distributions. When the frequencies are properly chosen, the AMFEIT yields reconstructions that are of the same quality as those based on conventional EIT that uses phase data.
Refractive index measurement based on surface plasmon resonance with optical fiber excitation structure and phase-detection using dual-frequency laser interferometry
Authors: Chen Qianghua , Liu Fuming , Lv Hongbo , Dou Zhaoliang , Ouyang Peixuan , Liu Fengbin , Wang Feng
Published: February 2025

The refractive index is an important physical characteristic that reflects material information. In this paper a refractive index measurement method based on surface plasmon resonance (SPR) with optical fiber excitation structure and phase-detection using a dual-frequency laser interferometer is presented. A four-layer fiber SPR model is built based on Kretschmann structure. Theoretical analyses indicate that the phase difference variation between p and s polarization components of the reflected light is approximately linear with the refractive index in a certain range, and thus the calculation formulae are derived. The presented optical measurement system meets the principle of the common optical path to get good anti-interference ability and stability. Signal processing adopts phase detection, which avoids the influence of light intensity fluctuation and achieves high resolution. The refractive index measurement experiments show that the results are consistent with the theoretical analysis. Comparison results with the Abbe refractometer show a good agreement. The presented method is a new attempt to combine fiber SPR with laser heterodyne interference phase measurement.
The MSPTDfast photoplethysmography beat detection algorithm: design, benchmarking, and open-source distribution
Authors: Charlton Peter H , Argüello Prada Erick Javier , Mant Jonathan , Kyriacou Panayiotis A
Published: February 2025

Objective: Photoplethysmography is widely used for physiological monitoring, whether in clinical devices such as pulse oximeters, or consumer devices such as smartwatches. A key step in the analysis of photoplethysmogram (PPG) signals is detecting heartbeats. The MSPTD algorithm has been found to be one of the most accurate PPG beat detection algorithms, but is less computationally efficient than other algorithms. Therefore, the aim of this study was to develop a more efficient, open-source implementation of the MSPTD algorithm for PPG beat detection, named MSPTDfast (v.2). Approach: Five potential improvements to MSPTD were identified and evaluated on four datasets. MSPTDfast (v.2) was designed by incorpo- rating each improvement which on its own reduced execution time whilst maintaining a high F1-score. After internal validation, MSPTDfast (v.2) was benchmarked against state-of-the-art beat detection algorithms on four additional datasets. Main results: MSPTDfast (v.2) incorporated two key improvements: pre-processing PPG signals to reduce the sampling frequency to 20 Hz; and only calculating scalogram scales corresponding to heart rates >30 bpm. During internal validation MSPTDfast (v.2) was found to have an execution time of between approximately one-third and one-twentieth of MSPTD, and a comparable F1-score. During benchmarking MSPTDfast (v.2) was found to have the highest F1-score alongside MSPTD, and amongst one of the lowest execution times with only MSPTDfast (v.1), qppgfast and MMPD (v.2) achieving shorter execution times. Significance: MSPTDfast (v.2) is an accurate and efficient PPG beat detection algorithm, available in an open-source Matlab toolbox.
Effective secondary electron yields for different surface materials in capacitively coupled plasmas
Authors: Beckfeld Florian , Masheyeva Ranna , Derzsi Aranka , Schulenberg David Alexander , Korolov Ihor , Bock Claudia , Schulze Julian , Donkó Zoltán
Published: February 2025

Processes at the plasma boundaries, including the electrodes, can significantly influence plasma properties, among them the plasma density, the flux-energy distribution of various particle species, etc. The emission of secondary electrons, in particular, can lead to ionization avalanches, which strongly increase the plasma density and change the discharge operation mode as a function of the operating conditions. Using reliable values to characterize the efficiency of such processes is indispensable for accurate numerical modeling. There is, however, a lack of such data for surface coefficients for arbitrary combinations of the plasma species and electrode materials and surface conditions. In this work, we investigate the α- to γ-mode mode transition induced by changes of the operating conditions (voltage, pressure) in capacitively coupled argon plasmas for different electrode surface materials (copper, nickel, gold, aluminum, and stainless steel) and target the determination of the effective in-situ secondary electron emission coefficient, γ∗. The first is accomplished by phase-resolved optical emission spectroscopy applied to measure the spatio-temporal distribution of the electron-impact excitation rate from the ground state into a high-threshold-energy level of a tracer gas (neon). The studies are conducted for pressures between 50 Pa - 200 Pa and voltage amplitudes ranging from 150 V - 350 V at a driving frequency of 13.56 MHz. A mode transition from the α- to the γ-mode is shown to take place at different pressures for different materials. The combination of these measurements with particle-in-cell / Monte Carlo collision simulations employing a range of γ∗ values allows the determination of the effective 'in-situ' electron yield for the given set of operating conditions. The simulations also shed light on the contributions of the various species, argon ions, metastable atoms, and vacuum-ultraviolet photons to electron emission from the electrodes. The findings suggest that for precise modeling individual secondary electron yields specific to different electrode surface materials should be used and multiple species should be included in the models that describe secondary electron emission at the electrodes.
A high rectification efficiency Dual Fin Si0.7Ge0.3/Si/Si0.7Ge0.3 Quantum Well Channel Structure FinFET for 2.45 GHz micropower microwave wireless energy harvesting
Authors: Ren Jiazhi , Song Jian-Jun , Zhang Yuchen
Published: February 2025

In wireless energy harvesting systems, the performance of rectifier diodes directly determines the upper limit of rectification efficiency. Schottky diodes and MOSFETs are currently the most widely used rectifier devices, but their performance is unsatisfactory in micro-power density input environments. To address this, this paper proposes and designs a high rectification efficiency FinFET model for 2.45 GHz micro-power microwave wireless energy harvesting using Sentaurus TCAD software simulation. When selecting 16 nm gate length, 6 nm fin width, and 53 nm fin height as the basic structural parameters of the FinFET device, the device’s subthreshold swing approaches the ideal value of 60 mV/dec, significantly enhancing the switching speed. Furthermore, a dual-fin structure is adopted to maintain excellent subthreshold swing characteristics and achieve a substantial increase in drive current strength. Finally, a dual-fin strained Si quantum well channel SiGe-OI FinFET structure is proposed to reduce the adverse effects of interfacial scattering on carrier mobility while introducing stress into the channel region to further enhance carrier mobility. The improvement in rectification efficiency is verified by constructing a half-wave rectifier circuit with filter capacitors via the Mixmode module. The rectification efficiencies reach 4.94% and 21.41% when the input power is -20 dBm and -10 dBm, respectively, which are 7 times and 3.4 times higher than conventional near-zero-threshold-voltage Si-based MOS devices under the same conditions.
Enhancing Electromagnetic Tracking: A Hybrid Pose Calculation Algorithm and a Novel Transmitting Coil Calibration Approach
Authors: Wen Shihan , Feng Yuke , Lai Jiacheng , Shi Jianqiao , Yang Rongqian
Published: February 2025

Medical electromagnetic tracking technology offers significant benefits in puncture and interventional surgeries by effectively mitigating obstacles. Traditional optimization-based algorithms for pose estimation in electromagnetic localization often converge to local optima and exhibit slow iterative convergence, which limits their accuracy and efficiency. To address these issues, we propose an enhanced pose estimation algorithm that integrates advanced optimization techniques for receiver sensors.The algorithm successfully converged to the global optimal solution in all test cases and no local optimal solution problem occurred in certain volume, which enables rapid real-time tracking of multiple coils simultaneously, outperforming traditional methods. Furthermore, we have developed a novel calibration method for transmission coils that corrects manufacturing-induced errors in size, position, and orientation. These innovations achieved system positional accuracy of 2.64 mm and directional accuracy of 1.33 degrees within a tracking volume of 350$ \times$ 350 $\times$ 350 $\text{mm}^3$.
The state-of-the-art of invasive brain-computer interfaces in humans: a systematic review and individual patient meta-analysis
Authors: Lim Mervyn Jun Rui , Lo Jack Yu Tung , Tan Yong Yi , Lin Hong-Yi , Wang Yu Hang , Tan Dewei , Wang Eugene , Naing Ma Yin Yin , Ng Joel Jia Wei , Jefree Ryan Ashraf Bin , Yeo Tseng Tsai
Published: February 2025

ObjectiveInvasive brain-computer interfaces (iBCIs) have evolved significantly since the first neurotrophic electrode was implanted in a human subject three decades ago. Since then, both hardware and software advances have increased the iBCI performance to enable tasks such as decoding conversations in real-time and manipulating external limb prostheses with haptic feedback. In this systematic review, we aim to evaluate the advances in iBCI hardware, software and functionality and describe challenges and opportunities in the iBCI field.ApproachMedline, EMBASE, and Cochrane databases were searched from inception until 13 April 2024. Primary studies reporting the use of iBCI in human subjects to restore function were included. Endpoints extracted include iBCI electrode type, iBCI implantation, decoder algorithm, iBCI effector, testing and training methodology and functional outcomes. Narrative synthesis of outcomes was done with a focus on hardware and software development trends over time. Individual patient data (IPD) was also collected and an IPD meta-analysis was done to identify factors significant to iBCI performance.Main results93 studies involving 214 patients were included in this systematic review. The median task performance accuracy for cursor control tasks was 76.00% (Interquartile range [IQR] = 21.2) , for motor tasks was 80.00% (IQR = 23.3), and for communication tasks was 93.27% (IQR = 15.3). Current advances in iBCI software include use of recurrent neural network architectures as decoders, while hardware advances such as intravascular stentrodes provide a less invasive alternative for neural recording. Challenges include the lack of standardized testing paradigms for specific functional outcomes and issues with portability and chronicity limiting iBCI usage to laboratory settings.SignificanceOur systematic review demonstrated the exponential rate at which iBCIs have evolved over the past two decades. Yet, more work is needed for widespread clinical adoption and translation to long-term home-use.
The design method of a high-rigidity support platform based on a multi-load optimization model
Authors: Zhao Yanyan
Published: February 2025

This paper presents a platform design method based on a multi-condition optimization model. This method primarily considers the stiffness of the platform to resist translational deformation in three orthogonal directions, as well as its ability to resist rotational deformation along the vertical axis. Additionally, the fundamental frequency of the platform is taken into account, treating all these loads as input loads for multi-load optimized design in the topology optimization process. Considering that the platform’s main load-bearing structure is assembled from a steel frame, the beam element was selected for finite element analysis and optimization design. The optimization method used was the Solid Isotropic Material with Penalization (SIMP) method. The optimization efficiency is determined by the number of beams, which is usually less than 1000. Therefore, the optimization efficiency of the proposed method is very high. This method was validated through case studies. The results showed that it can yield a concept design configuration of a platform in a few minutes, and the performance under comprehensive working conditions has been greatly improved.
Research and exploration of rubber band ejection system for small vehicles
Authors: Liu Chengge
Published: February 2025

With the widespread use of small unmanned aerial vehicles, there is a growing need to improve takeoff efficiency and takeoff accuracy. The shift from the traditional rocket-boosted takeoff method to a more flexible launch method has become critical. Rapid response, simplicity of launch, flexibility of location, and low cost become necessary for new launch methods. In this thesis, we have developed a system for launching a small flying vehicle using the rubber strap ejection technique. The system mainly consists of a rotating lifting base platform, an ejection system, and a small vehicle. We analyze the various parts of the ejection system in detail, including the sliding table, the energy storage structure, the trigger, and the buffer structure, and design and test a small vehicle. Experimental results show that this rubber ejection system provides stable, accurate launches that excel in repeatability and efficiency. Specifically, the system demonstrates excellent launch stability, reliability, and launch repeatability, proving its potential in a variety of real-world application scenarios. Demonstrating robust performance and a wide range of applications, this rubber ejection system provides a new, efficient solution for launching small vehicles.
Analysis of the causes of cracks in the cladding layer of the extraction tower
Authors: Deng Cong , Liu Jiayue , Luo Weijian , Li Xufeng , Yang Ruizeng
Published: February 2025

Pressure class special equipment is essential to the operation of a petrochemical production plant. Any failure in this equipment can lead to disastrous consequences. Therefore, during maintenance, it is crucial for technicians to quickly identify equipment problems, analyze their causes, and address them promptly to ensure safe operation. This paper takes a phenol acetone plant (PA) extraction tower as an example, for the penetration test found in the cladding cracks, to carry out background investigation, macro-inspection, spectral analysis, hardness testing, ferrite testing, and metallurgical testing. After comprehensive analysis, it is believed that the surface crack of the cladding layer is caused by chloride stress corrosion cracking, which is caused by improper welding process in the manufacturing process, resulting in large residual stress and intergranular sensitization of 300 series stainless steel. At the same time, according to the actual situation of the site, opinions on disposal and suggestions for subsequent use are given, which provides a reference for the inspection and testing of similar equipment.
Processing performance and regular of 6061 aluminum alloy by longitudinal-torsional ultrasonic milling
Authors: Zhao Yu , Wu Chenjun , Li Xuewei
Published: February 2025

The application of ultrasonic vibration-assisted cutting in machining is also increasing. In order to provide practical guidelines for industrial applications, a single-factor experimental method was employed to compare the surface morphology and surface roughness of 6061 aluminum alloy processed by longitudinal-torsional ultrasonic machining and conventional machining in end milling and side milling. The influence of ultrasonic amplitude on surface quality was systematically analyzed. The experimental results indicate that the surface morphology of both longitudinal-torsional ultrasonic end milling and side milling exhibit similar regular fish-scale-like textures. In contrast, the surface of conventional end milling exhibited arc-shaped concave-convex scratches, while the surface morphology of conventional side milling displayed irregular wavy textures. The surface roughness of longitudinal-torsional ultrasonic end milling is higher than that of conventional end milling, whereas the surface roughness of longitudinal-torsional ultrasonic side milling is lower than that of conventional side milling. Overall, the surface quality achieved through ultrasonic side milling is superior to that of conventional side milling.
Microstructures and properties optimization of Co-Ni based superalloy manufactured by direct laser energy deposition laser process
Authors: Wen Mingyue , Ren Hanwen , Li Wen
Published: February 2025

Superalloy is widely used in the hot-section parts of the aero-engines due to its excellent performance at elevated temperatures. In this paper, a new Co-Ni based superalloy was designed and printed using direct laser energy deposition (DLED), and 17 groups of depositions with different process parameters were set. This paper discusses the effects of process parameters on the deposition metals’ morphologies, microstructures, and mechanical properties, and figures out the process parameter for the DLED formation of Co-Ni based superalloy, with the best microstructure quality and mechanical properties.
NVH performance optimization of an electric vehicle compressor bracket
Authors: Ruan Xianzhen , Sun Lingling , Yao Mengliang , Ye Xiang , Xu Zichen
Published: February 2025

Electric vehicle compressor bracket is a key component that affects the noise, vibration, and harshness (NVH) performance of the vehicle. This paper first uses Hypermesh software to model and mesh the compressor bracket system, and uses modal analysis and frequency response analysis to determine the natural frequency and maximum vibration mode position of the bracket system; secondly, an optimization scheme is proposed for the defective position of the bracket; finally, the vibration isolation rate test verifies the improvement effect of the bracket optimization scheme, and the results show that the vibration isolation rate of the new scheme has been significantly improved. The innovation of this study is that frequency response analysis was combined with structural optimization to systematically optimize and experimentally verify the NVH performance of the compressor support system for the first time. The research method of this paper can provide a certain reference for solving such problems.
Prediction model for lifting performance in deep-sea mining based on flow patterns
Authors: Chen Hailong , Jiang Pan , Xiong Ting , Tang Dingding
Published: February 2025

Utilizing the momentum theorem, flow pattern analysis, and the drift flux method, a comprehensive theoretical model for air lifting in gas-liquid-solid transportation within deep-sea mining has been developed. The results indicate that as the gas mass flow rates increase, there is an initial rapid rise in the particle mass flow rates, followed by stabilization. Concurrently, lifting efficiency shows an initial increase before declining, peaking at lower gas mass flow rates. Increasing the riser diameter or immersion ratio, as well as deepening the air injection port, significantly enhances both the particle mass flow rates and lifting efficiency, while expanding the range of highly efficient gas mass flow rates to improve system lifting capacity. This suggests that under high immersion rates or with larger injection port depths, an air lifting system can utilize a higher gas mass flow rate to enhance production capacity. This study not only provides effective theoretical support for air lifting systems in deep-sea mining but also introduces novel concepts and avenues for further research and engineering practice in related fields.
Research and analysis of AP1000 nuclear fan belt fracture fault
Authors: Li Shuaishuai , Wang Yang , Qu Tianzuo , Ou Ruiheng , Wang Dalin , Meng Weiyan
Published: February 2025

Belt breakage faults often occur in the supply fan of the radioactive waste building in the nuclear power plant. To avoid affecting the normal operation of the fan, the regular replacement frequency of the fan belt was shortened, but the breakage still occurred. Through testing and analysis of belts produced by different manufacturers, a detailed and in-depth analysis was conducted from different perspectives, and corresponding conclusions were drawn. At the same time, follow-up action suggestions were also provided, providing a good reference for improving the operational reliability of similar fans.
Effect of assembly misalignment and weld crack on the maximum pressure of pipeline in-service repair
Authors: Wu Mingchang , Xu Yan , Guo Lei , Huang Liangliang , Lu Yongxin
Published: February 2025

The influence of assembly misalignment and welding crack on the maximum pressure in pipeline repair was investigated using numerical simulation methods in this work. The result indicated that the pipeline doesn’t need to be depressurized when welding misalignment is less than or equal to 5mm for the calculated X70 and X80 pipelines. Besides, when the specifications of X80 pipe was 1219×22 mm, the crack depth to pipe diameter was 0.20~0.40, the crack depth to crack length was 0.20~0.80, and the repair pressure level was the highest, with a range of 8.2~11.4 MPa. The maximum repair pressure was distributed with a range of 7.1~9.5 MPa when the thickness of the pipe decreased to 18.4 mm. The pipeline maximum repair pressure increased with the increase in pipe wall thickness. The maximum repair pressure was up to 14 MPa when the pipeline specification was Φ1016-26.2.
Study on the parameters of DLC coating preparation process based on COMSOL
Authors: Li Tianyi
Published: February 2025

The process of preparing DLC coatings by vacuum evaporation was simulated using COMSOL software. The distance between the evaporation source and the substrate, as well as the temperature of the evaporation source, were changed, and the influence of these parameters on the quality of the coating was analyzed. The results of the simulation experiment indicate that the coating prepared by vacuum evaporation has the thickest center and thinner edges compared to the center. Appropriately increasing the distance between the evaporation source and the substrate material can improve the uniformity of the coating; Raising the temperature has a significant impact on accelerating the sedimentation rate.
Measurement and calibration of discrete element parameters for extruded floating feed pellets and ABS plastic
Authors: Wang Liang , Ji Mingdong , Zheng Yuanhong , Zheng Yuqing
Published: February 2025

In the design and optimization of pneumatic feeding equipment for industrialized recirculating aquaculture systems (RAS), it is essential to simulate the separating and air-blowing process of floating feed pellets through the engineering discrete element model (EDEM). To improve the accuracy of the discrete element model (DEM), both computational simulations and physical tests were performed to adjust the relevant values. A DEM for feed pellets was created by sampling and measuring their inherent characteristics (density, Poisson ratio, and shear modulus) along with interaction parameters (restitution coefficient, and both static and rolling friction coefficients among pellets and between pellets and ABS). The restitution, static friction, and rolling resistance coefficients between puffed floating feed pellets and ABS plastic were calibrated via collision-rebound, inclined plane sliding, and rolling tests. Their calibrated values were 0.533, 0.331, and 0.069, respectively.
Analysis of aerodynamic loads in equipment compartments of high-speed trains
Authors: Xia Nanling , He Yanjing , Zhang Yongchang
Published: February 2025

This paper studied the pressure distribution on the side wall and bottom of the CH3 train equipment compartment at a speed of 300km/h under aerodynamic loading through numerical simulation. The results show that negative pressure exists on the surface of the equipment compartment, and the pressure at the downstream position is higher than that at the upstream position. With the development of the flow field at the downstream position of the bottom and side wall of the equipment compartment, the pressures in the head and middle equipment compartments gradually stabilize, while the pressure in the tail equipment compartment decreases. In addition, the pressure increase at the bottom of the equipment compartment is more pronounced than that at the sidewalls. The pressure change trends of the sidewalls at different heights are similar, but the higher the height above the ground, the greater the pressure fluctuation. The lateral and bottom pressure distributions in the equipment compartment of the train are more likely to be affected by the location of the equipment compartment. This study provides an important reference for the aerodynamic design and safety of the equipment compartment of high-speed trains, lays a basic steady state foundation for the study of other influencing factors.
Analysis of factors affecting uniformity of engine coolant flow rate
Authors: Zhang Longfei , Xu Honghai
Published: February 2025

Aiming at the short service life of an engine cooling water sleeve caused by uneven heating, the CFD model is established using STAR-CCM+ software, and the flow field simulation in the cooling water sleeve is completed. Based on this premise, the orthogonal test design method is employed to investigate the effects of cross-section size and allocation of cylinder holes in various areas of the cooling water sleeve on the uniformity of coolant velocity. The results show that the cylinder holes near the thermostat outlet have the most significant impact on the coolant velocity uniformity, followed closely by the cylinder holes near the coolant inlet and, finally, the cylinder holes near the EGR cooler outlet. Furthermore, it is observed that the uniformity of the velocity increases with the decrease of the cross-section areas of the cylinder holes located near the thermostat as well as the EGR coolant, with the increase of the cross-section areas of the cylinder holes near the inlet, which decreases firstly and then increases later. The study results hold substantial reference value for optimizing this engine’s cooling water sleeve structure.