Miracle-dz/UniFAR-FTUs huggingface dataset:
Flow and Particle Dispersion in Lung Acini: Effect of Geometric and Dynamic Parameters During Synchronous Ventilation

The human lung comprises about 300 million alveoli which are located on bronchioles between the 17th to 24th generations of the acinar tree, with a progressively higher population density in the deeper branches (lower acini). The alveolar size and aspect ratio change with generation number. Due to successive bifurcation, the flow velocity magnitude also decreases as the bronchiole diameter decreases from the upper to lower acini. As a result, fluid dynamic parameters such as Reynolds (Re) and Womersley (α) numbers progressively decrease with increasing generation number. In order to characterize alveolar flow patterns and inhaled particle transport during synchronous ventilation, we have conducted measurements for a range of dimensionless parameters physiologically relevant to the upper acini. Acinar airflow patterns were measured using a simplified in vitro alveolar model consisting of a single transparent elastic truncated sphere (representing the alveolus) mounted over a circular hole on the side of a rigid circular tube (representing the bronchiole). The model alveolus was capable of expanding and contracting in-phase with the oscillatory flow through the bronchiole thereby simulating synchronous ventilation. Realistic breathing conditions were achieved by exercising the model over a range of progressively varying geometric and dynamic parameters to simulate the environment within several generations of the acinar tree. Particle image velocimetry was used to measure the resulting flow patterns. Next, we used the measured flow fields to calculate particle trajectories to obtain particle transport and deposition statistics for massless and finite-size particles under the influence of flow advection and gravity. Our study shows that the geometric parameters (β and ΔV/V) primarily affect the velocity magnitudes, whereas the dynamic parameters (Re and α) distort the flow symmetry while also altering the velocity magnitudes. Consequently, the dynamic parameters have a greater influence on the particle trajectories and deposition statistics compared to the geometric parameters. The results from this study can benefit pulmonary research into the risk assessment of toxicological inhaled aerosols, and the pharmaceutical industry by providing better insight into the flow patterns and particle transport of inhalable therapeutics in the acini.
Legendre polynomial expansion method for evaluating multipole moments of current density in toroidal devices

It is found that multipole moments of toroidal current are given by the coefficients of the Legendre polynomial expansion of the magnetic field on a meridian contour. Using this fact and the orthogonality of the Legendre polynomials, a method is proposed for evaluating the moments from magnetic field measurements through an open-contour. As an application, exact expressions of the first few order moments and the current center position are formulated. Results show that this method is applicable to any aspect ratio tokamaks without the limitation of small displacement of the current center.
Medich Giant Platelet Syndrome: An Evolving Qualitative and Quantitative Platelet Disorder

Qualitative platelet disorders remain rare and varied. We describe here 2 additional patients with giant platelets, thrombocytopenia, deficiency in alpha granules and the presence of membranous inclusions within the cytoplasm. Collectively known as Medich syndrome, we further elucidated structural and clinical features of this rare syndrome. Platelets obtained from 2 patients with macro-thrombocytopenia were evaluated by electron microscopy. Structural findings were correlated with clinical characteristics. The defining morphologic feature found in the platelets of these patients is the presence of long, tubular inclusions consisting of several layers of membrane wrapped around a core of cytoplasm. These inclusions may deform the discoid shape of the platelet. In addition, abnormal giant alpha granules are present. Clinically all patients in the current report and review of the literature had mucosal bleeding and were often misdiagnosed as having immune related thrombocytopenia. To date five cases of Medich giant platelet syndrome have been reported. The cases are unified by the ultrastructural findings of abnormal alpha granules and unusual cytoplasmic scrolls. All patients experienced mucosal bleeding, however many clinical, biologic and genetic characteristics of this rare disorder remain to be determined.
COVID-19 vaccine hesitancy trends in Ghana: a cross-sectional study exploring the roles of political allegiance, misinformation beliefs, and sociodemographic factors

Introduction Africa has the slowest COVID-19 vaccination rate of any continent in the world, with only 29.8% of the population receiving at least one dose of the vaccine. This includes Ghana, where only 37.8% of the country have received at least one dose as of October, 2022. The key aims of this research were to determine levels of hesitancy in COVID-19 vaccines among unvaccinated individuals in Ghana and observe their trends across time, and to identify independent predictors associated with vaccine hesitancy among unvaccinated individuals. Methods four online cross-sectional surveys of Ghanaian citizens were conducted in August, 2020 (N = 3048), March, 2021 (N = 1558), June, 2021 (N = 1295), and February, 2022 (N = 424). Results overall hesitancy decreased from 36.8% (95% CI: 35.1%-38.5%) in August, 2020 to 17.2% (95% CI: 15.3%-19.1%) in March, 2021. However, hesitancy increased to 23.8% (95% CI: 21.5%-26.1%) in June, 2021, and then again to 52.2% (95% CI: 47.4%-57.0%) in February, 2022. Key reasons included not having enough vaccine-related information (50.6%) and concerns over vaccine safety (32.0%). Hesitant groups included Christians, urban dwellers, opposition political party voters, females, individuals who completed higher education, individuals who reported receiving COVID-19 information from internet sources, and individuals who expressed uncertainty about commonly-circulated COVID-19 misinformation beliefs. Conclusion hesitancy rates among unvaccinated individuals in Ghana continues to rise. However, vaccine awareness strategies are sensitive to subpopulation characteristics. Many are reachable through targeted communication strategies, to which campaigns must focus on resolving vaccine-related concerns to ensure high vaccine uptake across Ghana.
The Relationships Between Work-Related Rumination, Employee Voice and Silence, Turnover Intention, and Job Satisfaction

How employees think about their work after the end of their working day has received renewed emphasis recently. Work-related rumination could affect employees' voice behaviour. Some employees could prefer to speak up about ideas or concerns that bother them on an ongoing basis, and other employees can choose instead to remain silent. This could further impact specific organisational outcomes, such as employees' satisfaction in their job and their intention to leave the organisation. The objective of this study was to investigate the relationships between work-related rumination, employee voice and silence, turnover intention, and job satisfaction. A cross-sectional research design was used to collect data from a general sample of employees (n = 332). Structural equation modelling methods were used for data analysis. The results showed the proposed direct relationships between the research constructs, except between affective rumination and employee voice, and also employee voice and job satisfaction. Indirect relationships also showed how employee voice and silence played mediating roles in the relationships between work-related rumination and turnover intention. Organisations should be aware of the dynamics between work-related rumination and employee voice and silence behaviour within their organisation as this affects outcomes.
Conceptual writing in college-level mathematics courses and its impact on performance and attitude

This study looks at the impact of college students’ writing on a regular basis about mathematical concepts. Specifically we examine the effect of this practice on performance and attitude while controlling for confounding factors. Two professors and a total of 97 students in four different classes participated in the study. Students in the writing groups were required to write a total of eight papers, each concentrating on an important concept in the course. All students were given a visual skills assessment at the beginning and end of the course. Students in the writing group were assessed to determine their attitude toward the writing assignments. Positive trends were associated with the writing group over the non-writing group in overall score and in all but one of six individual components. However, within the writing group, students’ attitude toward writing in mathematics class was negative.
Small Fluctuation of Coronal X-Ray Intensity and a Signature of Nanoflares

If small energy events (nanoflares) contribute to the heating of the solar corona, they may be too small to be recognized as independent events. We create a simple histogram of the X-ray intensity fluctuation around the mean intensity and find that the histogram consists of a central Gaussian component and a wing component. The Gaussian component corresponds to random fluctuation around the mean intensity. The width of this component becomes broader with increasing intensity and is larger than the predicted photon noise distribution. We suggest that nanoflares produce the observed fluctuation of the X-ray intensity. The energy of nanoflares is estimated to be less than 1022 ergs to explain the observed fluctuation for active regions. It is estimated that if the energy of nanoflares is 1020 ergs, then these nanoflares must occur at a rate of 106 s-1 in a single active region (~1020 cm2) to supply the required energy (~5 × 107 ergs cm-2 s-1) to maintain the corona.
Instructional support for first-generation Hispanic students during the COVID-19 pandemic

Students of Hispanic descent make up the single largest subset of first-generation students enrolled in colleges and universities in the United States. These students have been the most affected by the economic and health consequences of the COVID-19 pandemic. They also have less support for their educational pursuits and more outside responsibilities than their continuing- generation counterparts. Best practices for creating an effective online learning environment are explored. Suggestions for helping students create social connections with instructors and fellow students are examined.
A model of laser imprinting

Irradiation nonuniformities in direct-drive (DD) inertial confinement fusion experiments generate, or “imprint,” surface modulations that degrade the symmetry of the implosion and reduce the target performance. To gain physical insight, an analytical model of imprint is developed. The model takes into account the hydrodynamic flow, the dynamics of the conduction zone, and the mass ablation. The important parameters are found to be the time scale for plasma atmosphere formation and the ablation velocity. The model is validated by comparisons to detailed two-dimensional (2D) hydrocode simulations. The results of the model and simulations are in good agreement with a series of planar-foil imprint experiments performed on the OMEGA laser system [T.R. Boehly, D.L. Brown, R.S. Craxton et al., Opt. Commun. 133, 495 (1997)]. Direct-drive National Ignition Facility’s [J.A. Paisner, J.D. Boyes, S.A. Kumpan, W.H. Lowdermilk, and M.S. Sorem, Laser Focus World 30, 75 (1994)] cryogenic targets are shown to have gains l.
Theoretical Study on the Generation of Switching Stress Waves in Power Semiconductor Devices

Appropriate condition monitoring methods can evaluate the status of power semiconductor devices in time. The traditional methods of condition monitoring are based primarily on the identification of electrical, magnetic, and thermal parameters. In recent years, studies have found that power semiconductor devices can generate stress waves when they are turned on and off, which can be detected by acoustic emission sensors. Acoustic emission detection technology has the characteristics of rapidity, noninvasiveness, and real-time performance. It is a supplement to conventional condition monitoring methods and is anticipated to be used for the online monitoring of power semiconductor devices. However, the source mechanism of the stress waves that power semiconductor devices produce when they turn on and off has not yet been identified, which is not conducive to the further application of acoustic emission detection technology in power semiconductor devices. Therefore, taking an insulated-gate bipolar transistor as an example, this article proposes new theoretical models to explain the reason for the stress wave generated by the device at the time of turn-off, and verifies the rationality of the models through formula derivations, finite-element simulations, and experimental results.
Effect of magnetic discontinuities on the propagation of energetic particles : Ulysses observations of the onset of the March 1991 solar particle event

We present observations of energetic ions from the Cosmic Ray and Solar Particle Investigation (COSPIN) and Heliosphere Instrument for Spectra Composition and Anisotropy at Low Energy (HISCALE) instruments on board the Ulysses spacecraft. We examine in detail the onset of energetic ions observed during the March 1991 series of solar events. Active region 6555, at E28 at 2247 UT on March 22, 1991 (day 81), was most likely responsible for the high-energy protons subsequently seen at Ulysses. A slow increase in the high-energy (∼50 MeV) proton intensity, made up of many small but rapid intensity increases, began around 9 hours after the onset of the event, taking 1.5 days to reach maximum intensity. On the flank, and in front of a coronal mass ejection (CME), coming from a previous event, we observed a region with a drop in the magnetic field strength. This region was populated with hot shocked plasma and, owing to the low magnetic field pressure, had an ion plasma beta >1. Mirror mode waves, with discontinuities appearing at the edges of the waves, produced a larger-than-average number of magnetic field discontinuities, a large fraction of the discontinuities being aligned with their normals oriented along the radial direction, suggesting that they were being convected outward by the CME. These discontinuities acted as a series of barriers to the propagation of the energetic solar particles coming from the solar event, delaying substantially the onset of the particle event at Ulysses.
Evaluation and Improvement of FY-4A/AGRI Sea Surface Temperature Data

The advanced geosynchronous radiation imager (AGRI) aboard the Chinese Fengyun-4A (FY-4A) satellite can provide operational hourly sea surface temperature (SST) product. However, the temporal and spatial variation of the errors for this product is still unclear. In this article, FY-4A/AGRI SST is evaluated using the in situ SST from 2019-2021, and a cumulative distribution function matching method is adopted to reduce the errors. Statistical results show that the mean bias and root-mean-square error (RMSE) of FY-4A/AGRI SST are −0.37 °C and 0.98 °C, the median and robust standard deviation (RSD) are −0.30 °C and 0.90 °C. The variations in daily and monthly errors are large and there are no prominent seasonal variations during the period analyzed. There are negative biases exceeding −1.0 °C in low-mid latitude regions and larger positive biases in southern high latitude region. There are dependencies of satellite SST minus in situ SST on satellite zenith angle and on SST itself. After the bias correction, the bias and RMSE are reduced to −0.02 °C and 0.72 °C, and the median and RSD are reduced to 0.00 °C and 0.60 °C. On the time scale, the fluctuation ranges of bias and median are smaller. The difference of satellite SST minus in situ SST can reflect the diurnal variation of SST. The biases are generally within ±0.2 °C in full disk. The error dependencies on satellite zenith angle and SST are also greatly reduced.
Capillary breakup of liquid threads: a singularity-free solution

The process of capillary breakup of a thread of Newtonian liquid is considered theoretically in the simplest case where the thread is surrounded by an inviscid, dynamically passive gas. The goal is to remove the singularities inherent in the known solutions to the problem obtained in the framework of the standard model and explain some puzzling qualitative features of the process observed in experiments. The analysis is based on the idea that, since the known solutions indicate that the rate at which fresh free-surface area is created tends to infinity as breakup is approached, one has that the surface tension, whose relaxation to equilibrium is always associated with a small but finite relaxation time, is bound to deviate from its equilibrium value in the process of breakup. This gives rise to a surface-tension gradient which starts to pull the liquid thread apart (the flow-induced Marangoni effect), whilst the role of the capillary pressure-driven squeezing of the liquid out of the neck diminishes as the surface tension in the minimal cross-section decreases. An earlier developed theory incorporating the interface formation process is applied without any ad hoc alterations and analysed in the framework of the slender-jet approximation. The resulting solution is singularity-free and allows one to describe some previously unexplained features of experiment by Kowalewski (1996, Fluid Dyn. Res., 17, 121).
Absolute cross sections for single and double charge-exchange in Feq+ impacting on He

We report measured absolute single and double charge-exchange cross sections (CSs) for Feq+ ions with He at the ion impact energy of 7.0 ? q keV for q = 5? 13. The range of ion velocities is 350 km s? 1 for q = 5, to 560 km s? 1 for q = 13, comparable to typical solar wind velocities. A retarding-field method is used for charge-state analysis of the ion beam after traversing the stationary target gas cell. The CSs are determined from absolute measurements of the ion currents and He target gas pressure.
THE KATO PROBLEM FOR OPERATORS WITH WEIGHTED ELLIPTICITY

We consider second order operators Lw = w 1 divAwr with ellipticity controlled by a Muckemphout A2 weight w. We prove that the Kato square root estimate L 1=2 w f L2(w) kr fkL2(w) holds in the weighted space L 2 (w).
Enhanced Adsorption Selectivity of Carbon Dioxide and Ethane on Porous Metal–Organic Framework Functionalized by a Sulfur-Rich Heterocycle

Porous metal–organic framework [Zn2(ttdc)2(bpy)] (1) based on thieno [3,2-b]thiophenedicarboxylate (ttdc) was synthesized and characterized. The structure contains intersected zig-zag channels with an average aperture of 4 × 6 Å and a 49% (v/v) guest-accessible pore volume. Gas adsorption studies confirmed the microporous nature of 1 with a specific surface area (BET model) of 952 m2·g–1 and a pore volume of 0.37 cm3·g–1. Extensive CO2, N2, O2, CO, CH4, C2H2, C2H4 and C2H6 gas adsorption experiments at 273 K and 298 K were carried out, which revealed the great adsorption selectivity of C2H6 over CH4 (IAST selectivity factor 14.8 at 298 K). The sulfur-rich ligands and double framework interpenetration in 1 result in a dense decoration of the inner surface by thiophene heterocyclic moieties, which are known to be effective secondary adsorption sites for carbon dioxide. As a result, remarkable CO2 adsorption selectivities were obtained for CO2/CH4 (11.7) and CO2/N2 (27.2 for CO2:N2 = 1:1, 56.4 for CO2:N2 = 15:85 gas mixtures). The computational DFT calculations revealed the decisive role of the sulfur-containing heterocycle moieties in the adsorption of CO2 and C2H6. High CO2 adsorption selectivity values and a relatively low isosteric heat of CO2 adsorption (31.4 kJ·mol–1) make the porous material 1 a promising candidate for practical separation of biogas as well as for CO2 sequestration from flue gas or natural gas.
Comparison of certain VLF noise phenomena with the lower hybrid resonance frequency calculated from simultaneous ion composition measurements

Certain VLF noise phenomena commonly observed with electric dipole antennas on the Alouette, OGO, and Injun 5 spacecraft have been associated with the lower hybrid resonance frequency of the ionospheric medium in the vicinity of the spacecraft. By using simultaneous VLF and ion mass spectrometer data from OGO 4, it has now become possible to compare the characteristic frequencies of these noise bands with the lower hybrid resonance frequency fLH calculated directly from ion composition measurements. The results of the study show a clear correspondence between the independent observations over a wide range of variation of fLH. Some differences between the VLF and the spectrometer results are also evident and suggest that the characteristic frequencies of lower hybrid resonance noise phenomena observed by satellite-borne VLF receivers may not always be determined in the immediate vicinity of the spacecraft.
A multidimensional model for aerosols - Description of computational analogs

Abstract The numerical algorithms which we use to simulate the advection, diffusion, sedimentation, coagulation and condensational growth of atmospheric aerosols are described. The model can be used in one, two, or three spatial dimensions. We develop the continuity equation in a generalized horizontal and vertical coordinate system which allows the model to be quickly adapted to a wide variety of dynamical models of global or regional scale. Algorithms are developed to treat the various physical processes and the results of simulations are presented which show the strengths and weaknesses of these algorithms. Although our emphasis is on the modeling of aerosols, the work is also applicable to simulations of the transport of gases.
High-Resolution Optical Imaging of the Large Magellanic Cloud Plerion 0540-69

The Crab-like SNR 0540-69 in the LMC has been investigated using the ESO NTT (New Technology Telescope) equipped with SUSI (SUperb Seeing Imager). B, V, O III, S II, and Hα images were collected under very good seeing conditions, yielding unprecedented detail on the picture of the expanding shell as well as of the synchrotron nebula, which is shown to harbor two maxima of emission. Both of these are seen to have magnitudes comparable to that of the optical pulsar reported by Middleditch et al. (1987, ApJ, 315), the northern one appearing more compact