Miracle-dz/UniFAR-FTUs huggingface dataset:
Rotor whirl forces induced by the tip clearance effect in axial flow compressors

It is now widely recognized that destabilizing forces, tending to generate forward rotor whirl, are generated in axial flow turbines as a result of the nonuniform torque induced by the nonuniform tip-clearance in a deflected rotor--the so called Thomas/Alford force. It is also recognized that there will be a similar effect in axial flow compressors, but qualitative considerations cannot definitively establish the magnitude or even the direction of the induced whirling forces--that is, if they will tend to forward or backward whirl. Applying a parallel compressor model to simulate the operation of a compressor rotor deflected radially in its clearance, it is possible to derive a quantitative estimate of the proportionality factor [beta] which relates the Thomas/Alford force in axial flow compressors (i.e., the tangential force generated by a radial deflection of the rotor) to the torque level in the compressor. The analysis makes use of experimental data from the GE Aircraft Engines Low Speed Research Compressor facility comparing the performance of three different axial flow compressors, each with four stages (typical of a mid-block of an aircraft gas turbine compressor) at two different clearances. It is found that the value of [beta] is in the range of +0.27 tomore » [minus]0.71 in the vicinity of the stages' nominal operating line and +0.08 to [minus]1.25 in the vicinity of the stages' operation at peak efficiency. The value of [beta] reaches a level of between [minus]1.16 and [minus]3.36 as the compressor is operated near its stalled condition. « less
Probing microdomain Ca2+ activity and synaptic transmission with a node-based tripartite synapse model

Astrocytic fine processes are the most minor structures of astrocytes but host much of the Ca2+ activity. These localized Ca2+ signals spatially restricted to microdomains are crucial for information processing and synaptic transmission. However, the mechanistic link between astrocytic nanoscale processes and microdomain Ca2+ activity remains hazily understood because of the technical difficulties in accessing this structurally unresolved region. In this study, we used computational models to disentangle the intricate relations of morphology and local Ca2+ dynamics involved in astrocytic fine processes. We aimed to answer: 1) how nano-morphology affects local Ca2+ activity and synaptic transmission, 2) and how fine processes affect Ca2+ activity of large process they connect. To address these issues, we undertook the following two computational modeling: 1) we integrated the in vivo astrocyte morphological data from a recent study performed with super-resolution microscopy that discriminates sub-compartments of various shapes, referred to as nodes and shafts to a classic IP3R-mediated Ca2+ signaling framework describing the intracellular Ca2+ dynamics, 2) we proposed a node-based tripartite synapse model linking with astrocytic morphology to predict the effect of structural deficits of astrocytes on synaptic transmission. Extensive simulations provided us with several biological insights: 1) the width of nodes and shafts could strongly influence the spatiotemporal variability of Ca2+ signals properties but what indeed determined the Ca2+ activity was the width ratio between nodes and shafts, 2) the connectivity of nodes to larger processes markedly shaped the Ca2+ signal of the parent process rather than nodes morphology itself, 3) the morphological changes of astrocytic part might potentially induce the abnormality of synaptic transmission by affecting the level of glutamate at tripartite synapses. Taken together, this comprehensive model which integrated theoretical computation and in vivo morphological data highlights the role of the nanomorphology of astrocytes in signal transmission and its possible mechanisms related to pathological conditions.
Mitochondrial Transfer to Host Cells from Ex Vivo Expanded Donor Hematopoietic Stem Cells

Mitochondrial dysfunction is observed in various conditions, from metabolic syndromes to mitochondrial diseases. Moreover, mitochondrial DNA (mtDNA) transfer is an emerging mechanism that enables the restoration of mitochondrial function in damaged cells. Hence, developing a technology that facilitates the transfer of mtDNA can be a promising strategy for the treatment of these conditions. Here, we utilized an ex vivo culture of mouse hematopoietic stem cells (HSCs) and succeeded in expanding the HSCs efficiently. Upon transplantation, sufficient donor HSC engraftment was attained in-host. To assess the mitochondrial transfer via donor HSCs, we used mitochondrial-nuclear exchange (MNX) mice with nuclei from C57BL/6J and mitochondria from the C3H/HeN strain. Cells from MNX mice have C57BL/6J immunophenotype and C3H/HeN mtDNA, which is known to confer a higher stress resistance to mitochondria. Ex vivo expanded MNX HSCs were transplanted into irradiated C57BL/6J mice and the analyses were performed at six weeks post transplantation. We observed high engraftment of the donor cells in the bone marrow. We also found that HSCs from the MNX mice could transfer mtDNA to the host cells. This work highlights the utility of ex vivo expanded HSC to achieve the mitochondrial transfer from donor to host in the transplant setting.
Dynamics of binary-disk interaction. 1: Resonances and disk gap sizes

We investigate the gravitational interaction of a generally eccentric binary star system with circumbinary and circumstellar gaseous disks. The disks are assumed to be coplanar with the binary, geometrically thin, and primarily governed by gas pressure and (turbulent) viscosity but not self-gravity. Both ordinary and eccentric Lindblad resonances are primarily responsible for truncating the disks in binaries with arbitrary eccentricity and nonextreme mass ratio. Starting from a smooth disk configuration, after the gravitational field of the binary truncates the disk on the dynamical timescale, a quasi-equilibrium is achieved, in which the resonant and viscous torques balance each other and any changes in the structure of the disk (e.g., due to global viscous evolution) occur slowly, preserving the average size of the gap. We analytically compute the approximate sizes of disks (or disk gaps) as a function of binary mass ratio and eccentricity in this quasi-equilibrium. Comparing the gap sizes with results of direct simulations using the smoothed particle hydrodynamics (SPH), we obtain a good agreement. As a by-product of the computations, we verify that standard SPH codes can adequately represent the dynamics of disks with moderate viscosity, Reynolds number R approximately 10(exp 3). For typical viscous disk parameters, and with a denoting the binary semimajor axis, the inner edge location of a circumbinary disk varies from 1.8a to 2.6a with binary eccentricity increasing from 0 to 0.25. For eccentricities 0 less than e less than 0.75, the minimum separation between a component star and the circumbinary disk inner edge is greater than a. Our calculations are relevant, among others, to protobinary stars and the recently discovered T Tau pre-main-sequence binaries. We briefly examine the case of a pre-main-sequence spectroscopic binary GW Ori and conclude that circumbinary disk truncation to the size required by one proposed spectroscopic model cannot be due to Linblad resonances, even if the disk is nonviscous.
Statistics of velocity field in laboratory-simulated downburst

As a laboratory model of downburst, the statistics of a turbulent velocity field of a vertical gravitational flow is investigated. By mechanically breaking a thin film fixed at the bottom of a cylindrical container, a finite mass of a high-density liquid begins to fall into a stationary low-density liquid, forming a vertical thermal. It impinges onto the horizontal ground and then diverges radially outward. By employing particle image velocimetry, the ensemble-averaged maps of velocity vectors, azimuthal vorticity, and turbulent stresses in a meridian plane are obtained. The statistical characteristics in the downdraft stage, impinging stage and diverging stage are examined. The nature and the role of the circulatory flow are demonstrated. The results show reasonable agreement with the actual downbursts observed in the atmosphere. Based on these results, the windshear hazard index for aircraft encountering a downburst is evaluated.
Microscale pressure fluctuations measured within the lower atmospheric boundary layer

Eulerian measurements of microscale fluctuations in static pressure are used, in conjunction with measurements of air velocity, to describe some of the properties of the static pressure fluctuations that occur within the turbulent flow of the lower atmospheric boundary layer. Using an instrument developed to measure the static pressure at a point within the boundary layer, data were collected at heights ranging from the surface up to about 6 m. The results are presented as power spectra, cross-spectra, coherence and phase. For all observations over a flat boundary the root-mean-square pressure produced by the boundary-layer turbulence is about 2.6 times the mean stress. The pressure spectra are found to have a, well-defined shape which does not change with height above the surface; at the higher frequencies the spectra show a power-law behaviour with a mean slope of −1·7. A number of observations with two pressure sensors are used to describe the structure and propagation velocity of individual pressure pulses. A dominant feature of the pressure-velocity relationship is that the large-scale pressure fluctuations are approximately in phase with the downstream velocity fluctuations; at small scales there is a large phase difference (∼−135°). These phase differences are interpreted to be the result of interaction of the large pressure-producing scales with the earth's surface, the small scales being ‘free’ of the surface. Prom the simultaneous measurements of pressure and downstream velocity the effect of pressure forces on the energy flux out of the downstream velocity fluctuations was evaluated. Typical values are about 0-45 of the net energy source to the downstream component. By means of pressure and vertical velocity measurements an estimate of the pressure divergence term in the net energy budget of a boundary layer is made. It was found to be about 1/10 of the energy feeding term.
The ambulatory transoral endoscopic thyroidectomy vestibular approach is safe and economical for patients with thyroid nodules

Background Ambulatory thyroid surgery has been increasingly performed in recent years. However, the feasibility of the ambulatory transoral endoscopic thyroidectomy vestibular approach (TOETVA) has not been evaluated. We aimed to evaluate the safety, economy, and mental health outcomes of ambulatory TOETVA. Methods We retrospectively reviewed the data of patients who underwent TOETVA between March 2019 and August 2022. The procedure was performed by a skilled surgical team from the Department of Thyroid Surgery of the affiliated Yantai Yuhuangding Hospital of Qingdao University. Patients were enrolled in the ambulatory (n=166) and conventional (n=290) groups, based on their chosen procedure. We analyzed patients’ clinical characteristics, surgical outcomes, Hamilton Anxiety Rating Scale (HAM-A) scores, and hospitalization costs. Results Of 456 patients, 166 underwent ambulatory TOETVA and 290 underwent conventional TOETVA. No significant differences were found in clinical and surgical characteristics between the groups, including sex (P=0.363), age (P=0.077), body mass index (P=0.351), presence of internal diseases (P=0.613), presence of Hashimoto’s thyroiditis (P=0.429), pathology (P=0.362), maximum tumor diameter (P=0.520), scope of surgery (P=0.850), or operative time (P=0.351). There were no significant differences in maximum tumor diameter (P=0.349), extrathyroidal tissue invasion (P=0.516), number of retrieved central lymph nodes (P=0.069), or metastatic central lymph nodes (P=0.897) between the groups. No significant differences were found in complications, including transient hypoparathyroidism (P=0.438), transient vocal cord palsy (P=0.876), transient mental nerve injury (P=0.749), permanent mental nerve injury (P=0.926), and other complications (P=1.000). Ambulatory patients had shorter hospital stays (P<0.001) and reduced hospitalization costs (P<0.001). There was no significant difference in HAM-A scores between the groups (P=0.056). Conclusions Ambulatory TOETVA is a safe, feasible, and cost-effective procedure for selected patients. This procedure resulted in shorter hospital stays, decreased medical costs, and did not increase patient anxiety. To ensure patient safety, surgical teams must inform patients of the indications, when to seek help, and how to receive the fastest medical attention.
Facial Age Estimation Models for Embedded Systems: A Comparative Study

Automated age estimation from face images is the process of assigning either an exact age or a specific age range to a facial image. In this paper a comparative study of the current techniques suitable for this task is performed, with an emphasis on lightweight models suitable for embedded implementation. We investigate both the suitable modern deep learning architectures for feature extraction and the variants of framing the problem itself as either classification, regression or soft label classification. The models are evaluated on Audience dataset for age group classification and FG-NET dataset for exact age estimation. To gather in-depth insights into automated age estimation and in contrast to existing studies, we additionally compare the performance of both classification and regression on the same dataset. We propose a novel loss function that combines regression and classification approaches and show that it outperforms other considered approaches. At the same time, with a lightweight backbone, such an architecture is suitable for implementation on embedded devices.
Knock, knock, who’s there? Leader humor, leader–member exchange, and the dimensions of engagement

The workplace is rife with the use of humor. However, the theoretical ties between the use of leader humor and common employee outcomes remain incomplete. This research extends social exchange theory to investigate the activities through which leader humor enables followers' physical, cognitive, and emotional engagement. The argument is made that leaders can utilize humor as a socioemotional resource to facilitate high-quality relationships with followers. Accordingly, hypotheses are developed to suggest a mediated relationship between leader humor and the three dimensions of engagement through the leader–member exchange (LMX). Data from a two-wave study in the United States support these hypotheses and highlight leader–follower exchange as a necessary linkage to follower engagement. These results suggest that it is not enough for leaders to be amusing. Instead, leaders need to build strong connections with their followers through the exchange of social and emotional support. This research adds to the knowledge of leader humor in the organizational setting by establishing a connection between leader humor and each of the engagement facets. Additionally, this research expands the LMX literature by drawing attention to leader humor as a valuable socioemotional resource.
Discrimination Neural Network Model for Binary Classification Tasks on Tabular Data

For the classification task, neural network-based approaches attempt to distinguish between two distributions by determining the joint distribution of input variables for each class. However, the most challenging task is still to classify the observations in the overlapping region of two classes. In this work, we propose a new discrimination neural network (DiscNN) architecture to address this issue. Our DiscNN learns to embed the initial input into more informative representations with better discriminability between the two distributions based on the cosine embedding loss. We also train our proposed model using the few-shot learning method to extract better-generalized representations from the initial input. We applied the DiscNN model to 35 tabular datasets from the OpenML-CC18 benchmark for a binary classification task. Our model showed superior performances on 28 datasets of them. In addition, we also performed experiments on 95 imbalanced datasets from the KEEL repository. The experiment results showed that the DiscNN outperformed the state-of-the-art models, including CatBoost, LightGBM, TabNet, VIME and Scarf, by around 0.23% AUC, 0.20% G-mean, and 1.06% F1 score.
Research on hot rolled steel strip defects image processing method based on multi-scale detection

Hot rolled steel strip is usually detected by image processing for defects, but it is often affected by light, and conventional image processing methods cannot effectively detect defects with small areas. In this paper, an image processing method is proposed to overcome the effect of fill light for the detection of steel strip surface damage by convolutional neural network multiscale detection method. In the target detection part, K-means++ clustering was performed on the anchor size, while the S-SPP module for multi-scale detection was introduced to further improve the detection of small-area damage. After training the model with the NEU-CLS dataset, the accuracy reached 94.6% and the detection speed was 27.3 ms. Through comparison experiments, the experimental results show that the proposed method of image processing can detect steel strip damage more accurately and faster, which provides a feasible method for practical application in factory scenes.
Surface reaction and Sm depletion at 550/spl deg/C for high temperature Sm-TM magnets

Sm/sub 2/(Co,Fe,Cu,Zr)/sub 17/ type magnets are unique high energy product magnet materials for applications at temperatures higher than 200/spl deg/C. These magnets have (BH)/sub max/ values up to 32 MGOe at 25/spl deg/C and up to 26.5 MGOe at 200/spl deg/C. A new, recently introduced class of these Sm-TM 2:17 type magnets can be used at temperatures as high as 550/spl deg/C. However, exposure to such high temperatures presents new challenges because of the reactions between the magnets and the environment. An investigation has been conducted using SEM/EDXA and EPMA/WDXA to study the microstructure formed in Sm/sub 2/(Co,Fe,Cu,Zr)/sub 17/ magnets after long-term exposure to air at 550/spl deg/C. It was anticipated that the permanent magnetic loss observed was due mostly to surface oxidation. Surprisingly, the investigation shows that the major cause for the magnetic loss is Sm depletion. It was found that at the surface layer, Sm is lost by vaporization, leaving an oxide of Fe-Co. But Sm depletion also occurs in a zone between the surface layer and the matrix of the samples. In this affected zone, many Sm free Fe-Co-Cu stripes are formed as part of the process of Sm atoms migrating toward the surface layer and eventually evaporating. Coating can minimize Sm depletion and reduce the magnetic loss. Research for improved coating systems is in progress.
Causes of incorrect carrier-type identification in van der Pauw–Hall measurements

The impact of macroscopic sample inhomogeneity and contact placement on the measured carrier type and concentration in the widely used van der Pauw–Hall method is investigated using finite-element analysis of the electrostatics. A variety of likely macroscopic inhomogeneities in mobility or carrier concentration across a square-shaped sample are considered. Inhomogeneities in mobilities do not affect the measured carrier type and concentration, as long as the carrier concentration remains homogeneous. Inhomogeneities in carrier concentrations can result in an incorrect assignment of the carrier type. However, when contacts are placed at the sample corners and not inside the sample area, the correct carrier type is recovered. Our calculations provide an explanation for recent measurements on ZnO [Ohgaki et al., J. Mater. Res. 23, 2293 (2008)]. Guidelines for avoiding incorrect interpretation of van der Pauw–Hall measurements are provided.
Keep the fire burning: Social entrepreneurs’ motives, role stress, perceived work competence and passion

This study examines factors affecting social entrepreneurs’ passion, focusing on their motives, job stress, and perceived work competence. The analysis of the survey data of 264 self-identified social entrepreneurs working in different types of organizations reveals that other-oriented motives are strongly associated with passion while self-oriented motives are not. The results also show that job stress is negatively correlated with social entrepreneurs’ passion. When the perceived work competence is included as a mediator, however, it alters the nature of the job stress-passion relationship, suggesting that job stress can positively affect social entrepreneurs’ passion when they perceive a high level of competence. The findings also suggest that perceived work competence reinforces the positive relationship between other-oriented motives and passion. This paper concludes with practical implications for social entrepreneurship education.
Ambient sea noise in waters near Australia

Ambient sea noise has been measured at 40 positions in mainly tropical waters near Australia: in the Indian Ocean; the Arafura and Timor Seas; and in the Coral and Tasman Seas (Pacific Ocean). Wind‐speed dependence was observed at all frequencies of measurement from 22 to 5000 Hz. At hydrophones suspended at depths between 8 and 25 m, the wind‐ dependent noise appeared to be independent of bottom depth which varied from 26 to 6700 m. The rate at which wind‐dependent noise increased with increasing wind speed was found to be significantly less than has been observed in the North Atlantic Ocean. Non‐wind‐dependent noise, observed at frequencies below 250 Hz, varied by about 10 dB within a particular sea and by up to 20 dB between seas, and could be broadly related to the relative shipping densities and propagation conditions in the individual seas. In the shallow Arafura and Timor Seas north of Australia, there is evidence that noise of distant shipping is not a significant component of the ambient noise. A.
Fully leaky guided mode study of the flexoelectric effect and surface polarization in hybrid aligned nematic cells

The fully leaky guided-mode optical-waveguide technique has been used to characterize the tilt profiles in two E7-filled hybrid-aligned nematic cells. The director distortion was measured with ac and dc voltages applied perpendicular to the substrates. By comparing the tilt profiles with model profiles produced using a free-energy minimization program, the flexoelectric coefficient of E7 at 20 °C has been measured as +1.5±0.2×10−11 C m. The effect of surface polarization in the cells has also been observed. This surface polarization is attributed to the influence of the homeotropic surface. The dipole alignment imbalance of the liquid crystal at the homeotropic surface has then been estimated.