Miracle-dz/UniFAR-FTUs huggingface dataset:
Measured and found wanting: reconciling mass-estimates of ultra-diffuse galaxies

The virial masses of ultra-diffuse galaxies (UDGs) have been estimated using the kinematics and abundance of their globular cluster populations, leading to disparate results. Some studies conclude that UDGs reside in massive dark matter halos while others, controversially, argue for the existence of UDGs with no dark matter at all. Here we show that these results arise because the uncertainties of these mass estimates have been substantially underestimated. Indeed, applying the same procedure to the well-studied Fornax dwarf spheroidal would conclude that it has an "overmassive" dark halo or, alternatively, that it lacks dark matter. We corroborate our argument with self- consistent mocks of tracers in cosmological halos, showing that masses from samples with $5 < N < 10$ tracers (assuming no measurement errors) are uncertain by at least an order of magnitude. Finally, we estimate masses of UDGs with HST imaging in Coma and show that their recent mass measurements (with adequate uncertainties) are in agreement with that of other dwarfs, such as Fornax. We also provide bias and scatter factors for a range of sample sizes and measurement errors, of wider applicability.
Mapping of the electrical activity of human atria. Multiscale modelling and simulations

Atrial fibrillation is one of the most common cardiac arrhythmias seen in clinical practice. Therefore, it is of vital importance to develop new technologies aimed at diagnosing and terminating this kind of arrhythmia, to improve the quality of life of patients and to reduce costs to national health systems. In the last years, new atrial mapping techniques based on multi-electrode systems are increasingly being used to map the atrial electrical activity in humans and localise and target atrial fibrillation drivers in the form of focal sources or rotors. However, significant concerns remain about their accuracy and experimental approaches to analyse them are limited due to their invasive character. Therefore, computer simulations are a helpful tool to overcome these limitations since they can reproduce with fidelity experimental observations, permit to split the problem to treat into more simple substudies, and allow the possibility of performing preliminary investigations impossible to carry out in the clinical practice. This PhD thesis is focused on the analysis for accuracy of the multielectrode mapping systems through computational models and simulations. For this purpose, we developed realistic multiscale models in order to simulate atrial electrical reentrant activity, first in a sheet of atrial tissue and, then, in the whole atria. Then, we analysed the effects of the multi-electrode geometrical configurations on the accuracy of localizing rotors, by using multi-electrode arrays with equidistant inter-electrode distances, as well as multi-electrode basket catheters with non-equidistant inter-electrode distances. After computing the intracavitary unipolar electrograms, we performed phase maps, phase singularity detections to track rotors, and dominant frequency maps. We finally found out that the accuracy of multi-electrode mapping systems depends on their position inside the atrial cavity, the electrode-to-tissue distance, the inter-electrode distance, and the contribution of far field sources. Furthermore, as a consequence of these factors, false rotors might appear and could contribute to failure of atrial fibrillation ablation procedures.
RESEARCH OF EXCESS KURTOSIS SENSITIVENESS OF DIAGNOSTIC SIGNALS FOR CONTROL OF THE CONDITION OF THE ELECTROTECHNICAL EQUIPMENT

Expediency of use of diagnostic signals excess kurtosis for recognition of two conditions of control object is proved. On examples of typical symmetric distributions bigger sensitivity of excess kurtosis to difference of diagnostic signals distributions in comparison with an integrated metrics is confirmed. An algorithm is proposed and the minimum sample size of the diagnostic signal is calculated to estimate the excess kurtosis required to detect defects in the diagnosed
A PARTICLE METHOD FOR AIRCRAFT WAKE BEHAVIOR ANALYSIS NEAR THE GROUND USING TURBULENCE MODELING

The purpose of this paper is to numerically simulate the aircraft wake during the landing and take off operations using a new mesh-free two-dimensional discrete vortex method associated to a method of distributed singularities, the Panel Method. A pair of (Lamb) free vortex cloud is used to represent the free vortices at the wing tips. Lamb vortices are also generated along the airport ground, whose strengths are determined to ensure that the no- slip condition is satisfied. The impermeability condition is imposed through the application of a source panel method. In order to keep the computational effort within a manageable range, the micro scale manifestations of the turbulence are taken into account using a second-order velocity structure function model which is adapted to the Lagrangian scheme. Numerical results showing the free vortex clouds trajectory and their interaction with the ground vortex cloud are presented, showing new vortex structures that result from this interaction.
Relationship between Self-Esteem, Area of Study, Phubbing, and Perceived Social Media Addiction among University Students

Due to its increasing importance in our lives, it is crucial to gain a comprehensive understanding of social media. This study contributes to the existing literature by examining data from the Gulf region in the Middle East. The study focuses on self-esteem, phubbing, area of study, and how students perceive themselves in terms of social media addiction. Hierarchical regression analysis was employed to examine the role of self-esteem, phubbing, and area of study (Science, Engineering, Social Science) in predicting perceived social media addiction, following an exploratory analysis. The results indicate that both phubbing and area of study were significant predictors of reported social media addiction. Specifically, compared to students with science majors, those with engineering and social science majors reported being 10% and 13% more addicted to social media, respectively. Additionally, students who reported engaging in phubbing rarely, sometimes, often, or always perceived themselves as being 10%, 19%, 26%, and 33% more addicted to social media, respectively, compared to those who reported never engaging in phubbing.
Connections in the development of tropical cyclone Mitch (1998): A tribute to the human loss in this calamity

Tropical cyclone Mitch, which occurred in October 1998 on the Caribbean Sea, is studied. Mitch affected countries in Central America, where it caused great economic and human losses, and the authors believe that the scientific community has not paid enough attention to this phenomenon. Two NE-SE oriented dipole patterns associated with their convergence-divergence zones contributed significantly to its formation and intensification, which are analyzed from the observational synoptic point of view. The most remarkable characteristics of this phenomenon in the mean field occurred between October 18 and November 4, 1998 when another NW-SE dipolar pattern was formed, consisting of a high-level anticyclone from North America (HLA) and a high-level anticyclone from South America (HLC). To discern these patterns, two data sources were used: the NCAR-ds627.0 (ERA-Interim) reanalysis and the NCEP/NCAR reanalysis. The simplest idealization of the NW-SE dipolar vortex is a tropical modon, which is an exact solution of the barotropic vorticity equation (BVE) on a rotating sphere. The role of the HLA and the HLC in the excitation of tropical waves is explored using a numerical spectral method for sutdying the normal mode stability of exact solutions of the BVE. The initiation of the tropical wave at low levels could be associated with disturbances at high levels of the most unstable normal mode.
The Epoch of Reionization: Observing Galaxies in Their Cradle

The epoch of reionization at the infancy of the Universe is one of the observational frontiers of modern astronomy. It has been the key focus of numerous studies over the past decade. Through an impressive advancement of observational capabilities both on the ground and in space, these efforts have resulted in a tremendous gain of insight. Even though many questions about the early Universe are still unanswered, with more than a thousand galaxies known at redshifts greater than 6, we understand the formation and life of the first galaxies better than ever before. I will present an observer’s view of the galaxies at the epoch of reionization, describing the preferred tool used to study the high-redshift Universe, the rest-frame UV luminosity function, and the main insights this has let to in recent years. The spectroscopic follow-up of photometrically pre-selected highredshift galaxy samples has an equally great predictive power about the epoch of reionization. I will illustrate this by presenting recent studies inferring the content of ionized hydrogen in the early Universe from spectroscopic follow-up campaigns.
Acoustic Receptivity of Compressible Tollmien-Schlichting Waves with an Efficient Time-Harmonic Linearized Navier-Stokes Method

The compressible formulation of the time-harmonic linearizedNavier-Stokes (LNS)method for acoustic receptivity prediction is described. The efficiency of the proposed approach is rooted in the assumption that the problems of interest only require the time-asymptotic solution of a few select frequencies. We explore the parabolic nature of the basic flow and of the Stokes layer, and we implement an efficient LU decomposition method to obtain the roughnessinduced steady perturbation and Tollmien-Schlichting wave. Before attempting to predict receptivity amplitudes, the compressible Stokes layer solution based on the linearized unsteady boundary layer equations is validated in the subsonic regime against an Orr-Sommerfeld-type equation. Further testing of the model is conducted by reproducing the experiments of King & Breuer in near incompressible conditions. The results are consistent with the analogue incompressible receptivity model, and reveal excellent agreement with finite-Reynolds number theory for two-dimensional instabilities. Qualitative agreement with the experimental results for oblique waves is observed. Differences can be partially explained by the choice of physical model used to determine the N-factors, which in turn are used to extrapolate amplitudes to the first-branch of stability. Ultimately, a comprehensive comparison with direct-numericalsimulation-based subsonic receptivity amplitudes is conducted, demonstrating the correctness of the mathematical model and numerical implementation described herein.
Measurement of the charge distribution deposited by an annular plasma synthetic jet actuator over a target surface

Annular plasma synthetic jet actuators demonstrated their ability to produce a tubular flow normal to the surface where the dielectric barrier discharge (DBD) is ignited. These fluid-dynamic actuators enhance the delivery of reactive species towards the target to be treated. In these actuators, long life charged particles are generated within the plasma region and then carried on by the induced flow. In this work, the potential distribution induced by charges deposited over an insulating target has been measured. Surface DBD actuators, made with different dielectric materials, have been supplied by different sinusoidal voltages at a constant average power supplying the discharge. Actuators with the exposed electrode connected to both the high voltage potential and grounded have been tested. The charge distribution accumulated on a target surface perpendicular to the flow has been measured at different time intervals with the plasma on. Charges advected by the flow are always positive. The potential distribution on the target surface generated by the charges has been measured. For both configurations, firstly an M-shaped distribution develops and, later on, it becomes bell-shaped. A charge build-up mechanism has been found to be faster when the exposed electrode is connected to the high voltage terminal. The target has been placed at a variable distance from 1 to 5 cm from the actuator surface. At a distance of 5 cm, induced potentials are two times smaller than those with the target at 1 cm. Measurements allow us to estimate a charge flux toward the target on the order of 1011 particles (cm2 s)−1. The results presented in this work show that the presence of charged particles in the jet flow outside the plasma could be an important factor to be accounted for when these plasma actuators are used for treatment purposes (indirect plasma treatment).
Test and Verification of a CubeSat Attitude Determination and Control System in Variable Magnetic Fields

The Center for Space Research and Assurance (CSRA) at the Air Force Institute of Technology (AFIT) continues to explore CubeSat initiatives for solving many current space security issues. Regardless of the mission requirements, the success of the CubeSat on orbit frequently depends on the Attitude Determination and Control System (ADCS) functioning correctly. Previous research at AFIT has demonstrated single axis control on a spherical air bearing test bed incorporated within a Helmholtz cage utilizing artificially strong magnetic fields for better signal to noise ratios which are not experienced on orbit. This research explores the process of redesigning, testing, and programming a new 6U CubeSat ADCS to operate in representative magnetic fields using a three wheel reaction wheel array (RWA). A second external magnetometer is utilized while its effect on the quaternion estimate (QUEST) is characterized. The RWA is modularized and displaced from the ADCS μcontroller by the addition of a separate μcontroller on the RWA to handle Hall sensor interrupts allowing the control and estimation task to run uninterrupted. The displacement of the RWA from the primary ADCS μcontroller, which includes the primary magnetometer, minimizes electromagnetic disturbances caused by the RWA on the magnetometer. A quaternion error Proportional-Integral-Derivative (PID) control law is used to control the ADCS test bed while an external motion capture system captures its true orientation. This research effort shows that the quaternion estimate degrades as the magnetic field strength is reduced. The ambient Earth magnetic field increased the final angle error by 7.1◦ during a 90◦ rotation maneuver when compared to the maximum Helmholtz cage condition.
Limestone replacements by fine crushed concrete and ceramic wastes during the production of Portland cement

Abstract This study assesses the feasibility of limestone (LS) replacement by recycled fine aggregates (RFAs) on grindability and Portland cement properties. Two RFA types generated from the fine fraction of crushed concrete and ceramic wastes are ground in 22-liters grinding mill at 310 and 400 ± 20 m2/kg Blaine fineness, and then incorporated at 20% and 35% rates in clinker cement mixtures. Because of their porous nature, RFAs required about 22% to 30% less communition energy than LS, which could be advantageous to reduce grinding costs for given Blaine fineness. Mortars prepared with RFA-based cements yielded better strength recovery over time and lower water sorptivity than LS-based cement, either due to promoted hydraulic activity or pozzolanic reactions. The comminution of RFA fillers to 400 ± 20 m2/kg fineness is a viable alternative to mitigate the dilution effect while maintaining similar grinding energy and mechanical strengths as the control 95% clinker cement.
State of the art timing in TOF-PET detectors with LuAG, GAGG and L(Y)SO scintillators of various sizes coupled to FBK-SiPMs

Time of flight (TOF) in positron emission tomography (PET) has experienced a revival of interest after its first introduction in the eighties. This is due to a significant progress in solid state photodetectors (SiPMs) and newly developed scintillators (LSO and its derivatives). Latest developments at Fondazione Bruno Kessler (FBK) lead to the NUV-HD SiPM with a very high photon detection efficiency of around 55%. Despite the large area of 4×4 mm2 it achieves a good single photon time resolution (SPTR) of 180±5ps FWHM. Coincidence time resolution (CTR) measurements using LSO:Ce codoped with Ca scintillators yield best values of 73±2ps FWHM for 2×2×3 mm3 and 117±3ps for 2×2×20 mm3 crystal sizes. Increasing the crystal cross-section from 2×2 mm2 to 3×3 mm2 a non negligible CTR deterioration of approximately 7ps FWHM is observed. Measurements with LSO:Ce codoped Ca and LYSO:Ce scintillators with various cross-sections (1×1 mm2 - 4×4 mm2) and lengths (3mm - 30mm) will be a basis for discussing on how the crystal geometry affects timing in TOF-PET. Special attention is given to SiPM parameters, e.g. SPTR and optical crosstalk, and their measured dependency on the crystal cross-section. Additionally, CTR measurements with LuAG:Ce, LuAG:Pr and GGAG:Ce samples are presented and the results are interpreted in terms of their scintillation properties, e.g. rise time, decay time, light yield and emission spectra.
Controlled generation of intrinsic near-infrared color centers in 4H-SiC via proton irradiation and annealing

We report on the generation and annihilation of color centers in 4H silicon carbide (SiC) by proton irradiation and subsequent annealing. Using low-temperature photoluminescence (PL), we study the transformation of PL spectra for different proton doses and annealing temperatures. Among well reported defect signatures, we observe omnipresent but not yet identified PL signatures consisting of three sharp and temperature stable lines (denoted TS1,2,3) at 768.8 nm, 812.0 nm, and 813.3 nm. These lines show a strong correlation throughout all measurement parameters, suggesting that they belong to the same microscopic defect. Further, a clear dependence of the TS1,2,3 line intensities on the initial implantation dose is observed after annealing, indicating that the underlying defect is related to implantation induced intrinsic defects. The overall data suggest a sequential defect transformation: proton irradiation initially generates isolated silicon vacancies which are transformed into antisite vacancy complexes which are, in turn, transformed into presumably intrinsic-related defects, showing up as TS1,2,3 PL lines. We present recipes for the controlled generation of these color centers.We report on the generation and annihilation of color centers in 4H silicon carbide (SiC) by proton irradiation and subsequent annealing. Using low-temperature photoluminescence (PL), we study the transformation of PL spectra for different proton doses and annealing temperatures. Among well reported defect signatures, we observe omnipresent but not yet identified PL signatures consisting of three sharp and temperature stable lines (denoted TS1,2,3) at 768.8 nm, 812.0 nm, and 813.3 nm. These lines show a strong correlation throughout all measurement parameters, suggesting that they belong to the same microscopic defect. Further, a clear dependence of the TS1,2,3 line intensities on the initial implantation dose is observed after annealing, indicating that the underlying defect is related to .
Integral invariants and decay of temporally developing grid turbulence

We present a study of a large-scale energy spectrum and integral invariants in temporally developing grid turbulence at mesh Reynolds numbers of ReM = 10 000 and 20 000 by employing direct numerical simulations (DNSs) in a periodic box. The simulations are initialized with a velocity field that approximates the wakes induced by the bars of conventional square grids. The turbulence statistics obtained in the temporal DNS agree well with those of the previous experiments in both the production and decay regions. The temporally developing grid turbulence also has a so-called non-equilibrium region, which is consistent with its spatially developing counterpart, where the normalized dissipation rate of turbulence kinetic energy (TKE), Ce, increases as the turbulence decays. The decay exponent n of TKE is n = 1.22 at ReM = 20 000 and n = 1.35 at ReM = 10 000, which are close to the values for the Saffman turbulence [i.e., 6/5 for ReM = 20 000 and 6(1 + p)/5 ≈ 1.36 for ReM = 10 000 with p ≈ 0.13 obtained by Ce ∼ tp at large t]. The longitudinal integral length scale and the TKE dissipation rate also exhibit temporal evolutions consistent with the Saffman turbulence for both ReM. The Saffman integral directly evaluated in the grid turbulence tends to be time-independent after the turbulence evolves for about 200 times of characteristic time scale defined by mesh size divided by the mean velocity of a fluid passing the grid. A direct evaluation of the TKE spectrum E(k) shows that E(k) ≈ Lk2/4π2 is valid for a finite range of low wavenumbers.We present a study of a large-scale energy spectrum and integral invariants in temporally developing grid turbulence at mesh Reynolds numbers of ReM = 10 000 and 20 000 by employing direct numerical simulations (DNSs) in a periodic box. The simulations are initialized with a velocity field that approximates the wakes induced by the bars of conventional square grids. The turbulence statistics obtained in the temporal DNS agree well with those of the previous experiments in both the production and decay regions. The temporally developing grid turbulence also has a so-called non-equilibrium region, which is consistent with its spatially developing counterpart, where the normalized dissipation rate of turbulence kinetic energy (TKE), Ce, increases as the turbulence decays. The decay exponent n of TKE is n = 1.22 at ReM = 20 000 and n = 1.35 at ReM = 10 000, which are close to the values for the Saffman turbulence [i.e., 6/5 for ReM = 20 000 and 6(1 + p)/5 ≈ 1.36 for ReM = 10 000 with p ≈ 0.13 obtained by Ce ∼.
t i

This study aimed to determine the anti-bacterial efficacy of 5 different medicinal plant extracts against Shiga toxin ( E. coli O157:H7) based on the in-vitro and in-vivo trial. A total of twenty-one (n=21) PCR-confirmed isolates were selected for detection of virulent genes in-vitro trial (zone of inhibition). For in-vivo trial, forty-two (n=42) day-old chicks were divided into seven equal groups randomly (n=6 birds/ group), and were classified as: G1 ( Azadirachta indica @ 18.25 mg/ml), G2 ( Melia azedarach @ 1 5.75 mg/ml), G3 ( Withania coagulans @ 25 mg/ml), G4 ( Nigela sativa @ 30 mg/ml), and G5 ( Calotropis procera @ 10 mg/ml) were taken as treatment groups, while G6 as a negative control, and G7 as a positive control. The results showed that 47.6% serovars were positive for the virulent gene ( Stx-1 ). Moreover, the highest zone of inhibition was observed in G5 (17.1 ± 0.60 mm, P<0.05) as compared to other groups, which indicated high anti-bacterial efficacy on in-vitro basis. The survival rate and weight gain of chicks were significantly higher (P<0.05) in G5 compared with all other groups. However, none of the medicinal plant extracts affect liver function and blood parameters. Finally, in conclusion, C. procera was found to be highly effective to protect birds against E. coli O157:H7 infection.