Miracle-dz/UniFAR-FTUs huggingface dataset:
Implicit and Multigrid Method for Ideal Multigrid Convergence: Direct Numerical Simulation of Separated Flow Around NACA 0012 Airfoil

Numerical investigation of flow separation over a NACA 0012 airfoil at large angles of attack has been carried out. The numerical calculation is performed by solving the full Navier-Stokes equations in generalized curvilinear coordinates. The second-order LU-SGS implicit scheme is applied for time integration. This scheme requires no tridiagonal inversion and is capable of being completely vectorized, provided the corresponding Jacobian matrices are properly selected. A fourth-order centered compact scheme is used for spatial derivatives. In order to reduce numerical oscillation, a sixth-order implicit filter is employed. Non-reflecting boundary conditions are imposed at the far-field and outlet boundaries to avoid possible non-physical wave reflection. Complex flow separation and vortex shedding phenomenon have been observed and discussed.
Evaluation the antibacterial effect of hydroalcoholic coffee extract on L. monocytogenes isolated from milk and milk products

Listeria spp . is a very resilient bacteria that can persist hostile dairy-processing environments and consequently, food safety challenges appear here with respect to control its growth. L. monocytogenes is the most important species that cause a great concern in both food processing and public health. Therefore, this study was performed to investigate the incidence of Listeria spp. in 450 samples of raw milk, pasteurized milk, flavored milk, dominate cheese, kareish cheese, small scale ice cream, large scale ice cream, small scale yoghurt, and large scale yoghurt (50 each) were collected from dairy farms, local dairy shops and street vendors in Qena city, Egypt. Listeria spp. were isolated from 27 (6%) out of the total samples examined. They were recovered from the tested market raw milk, kareish cheese, small scale ice cream and domiati cheese samples with percentages of 20, 16, 14% and 4%, respectively. However, Listeria spp. was absent in other analyzed samples. The most prevalent species was L. monocytogenes 10 (2.22%), followed by L. grayii 9 (2%), L. welshimeri 4 (0.89%) and L. innocua 3 (0.67%) with an overall 5.7% verified by PCR. Eight out of 10 L. monocytogenes isolates were confirmed by the presence of the 16S rRNA gene that implies a risk of food-borne listeriosis among dairy product consumers. Furthermore, a unique approach was used for the assessment of antibacterial activity of different concentrations of gentamicin as a reference antibiotic standard and hydroalcoholic coffee extract (H. A. coffee extract) (1, 3, 10 and 30 µg/ml) against local isolated L. monocytogenes strain in vitro using a microplate in ELISA reader is provided in the current work. The most Potent antimicrobial activity of gentamicin and H. A. coffee extract was obtained at 30 µg/ml against the isolated L. monocytogenes strain. At which not exhibit listeria growth up to 98.3 % and 96.1 %, respectively. H. A. coffee extract was screened using gas chromatography–mass spectrometry (GC-Mass). This analysis showed that the antibacterial impact of H. A. coffee extract against L. monocytogenes is attributed to the active components (caffeine and eugenol).
Semi-parametric estimation of models for the means and covariances in the presence of missing data

In this article we describe a class of inverse-probability-of-censoring-weighted estimating equations for jointly estimating the parameters of models for the conditional mean and covariance of a vector of responses given a set of regressors in the presence of monotone missing outcome data. Our methods are valid when the data are missing at random in the sense of Rubin (1976) and do not require a parametric model for the joint distribution of the data. However, they do require a model for the non-responsive probabilities. We show that the solution to the optimal estimating equation in our class has asymptotic variance equal to the semiparametric variance bound. Because the optimal estimating equation depends on unknown population parameters, we propose an adaptive locally efficient estimator whose asymptotic variance can achieve the semiparametric variance bound.
A survey on geometry of warped product submanifolds

The warped product $N_1\times_f N_2$ of two Riemannian manifolds $(N_1,g_1)$ and $(N_2,g_2)$ is the product manifold $N_1\times N_2$ equipped with the warped product metric $g=g_1+f^2 g_2$, where $f$ is a positive function on $N_1$. The notion of warped product manifolds is one of the most fruitful generalizations of Riemannian products. Such notion plays very important roles in differential geometry as well as in physics, especially in general relativity. Warped product manifolds have been studied for a long period of time. In contrast, the study of warped product submanifolds was only initiated around the beginning of this century. In this article we survey important results on warped product submanifolds in various ambient manifolds. It is the author's hope that this survey article will provide a good introduction on the theory of warped product submanifolds as well as a useful reference for further research on this vibrant research subject.
THE FILLING FACTOR–RADIUS RELATION FOR 58 H ii REGIONS ACROSS THE DISK OF NGC 6946

Using the OSIRIS tunable narrowband imager on the 10.4 m GTC (La Palma), we have mapped the SAB(rs)cd galaxy NGC 6946 over a ∼7.3 × 7.5 arcmin2 field in the emission lines of the [S ii] λλ6717, 6731 doublet, and in Hα. From these maps we have produced catalogs of the Hα luminosities and effective radii of 557 H ii regions across the disk, and derived the [S ii] emission line ratios of 370 of these. The Hα observations were used to derive the mean luminosity-weighted electron densities for the regions of the sample, while the [S ii] line ratios allowed us to derive values of the in situ electron densities in the denser zones from which the major fraction of the radiation in these lines is emitted for 58 of the regions. This is by far the largest data set of its kind for a single galaxy. A classical two-phase model is used to derive the filling factors of the regions. We find that although the mean electron density decreases with the square root of the radius of the regions, the in situ density is essentially independent of this radius. Thus the filling factor falls systematically, as the radius and the luminosity of the regions increases, with a power law of exponent −2.23 between filling factor and radius. These measurements should enhance the perspectives for more refined physical models of H ii regions.
Chewing activities, sorting behaviour and ruminal fermentation of lactating dairy cows fed diets with similar proportions of undigested neutral detergent fibre with wheat straw substituted for alfalfa hay, corn silage or both

Abstract Feeding behaviour and ruminal fermentation of dairy cows were evaluated when fed diets formulated to supply a similar proportion of undigested neutral detergent fibre (uNDF) after 30-h incubation (uNDF30), while wheat straw (WS) replaced for corn silage (CS), alfalfa hay (AH) or both. In a randomised block design, 32 multiparous Holstein cows (days in milk = 78 ± 11 d, milk production = 56 ± 6 kg/d) were used. AH and CS were the only forage sources in control diet (CSAH). WS was substituted for alfalfa hay (WSCS), CS (WSAH) or both (WSCSAH) on uNDF30 basis. Dry matter consumption from 6 to 24 h after feed delivery was lower in WSAH than in WSCS or CSAH. No difference existed in total time spent for eating (250 min/d), rumination (460 min/d) and chewing (710 min/d). Total concentration of volatile fatty acids (VFAs) in the rumen was not different between treatments but propionate proportion was lower for cows fed WSAH than CSAH diet (19.0 vs. 24.1 mM/100 mM). Ammonia nitrogen concentration in the rumen fluid was greater for WSAH than WSCS or CSAH. With combining uNDF288 and peNDF, peuNDF288 was calculated and its intake had the highest correlation with chewing time (r = −0.60), sorting index of particles retained on 8-mm sieve (r = 0.42) and rumen pH (r = 0.52). Forage replacement on uNDF30 basis resulted in a relatively similar response on feeding behaviours and ruminal fermentation and enabled to replace high-quality forages with low-quality forages in the dairy cow rations. Highlights Wheat straw (WS) was substituted for alfalfa hay (AH), corn silage (CS) or both on an uNDF30 basis. Treatments had small differences in chewing patterns and ruminal fermentation. Combination of uNDF288 and diet particle size improved correlation coefficient with chewing, long particle intake and rumen pH.
International student mobility and labour market outcomes: The role of personality dimensions

International student mobility (ISM) is often perceived to enhance career prospects. Surprisingly, the role of personality traits in explaining why students go abroad and relationships between ISM and labour market outcomes have received scant scholarly attention. Based on survey data from Norwegian graduates, we found that degree and credit mobility graduates were significantly more extraverted and open than non-mobile peers and that degree mobiles were more agreeable than both credit and non-mobiles. Furthermore, results revealed that whereas degree mobility is related to both wage and Occupational self-efficiacy (OSE), this was not the case for credit mobility. However, personality did affect the associations between degree mobility and labour market outcomes. In sum, our study suggests that the distinction between degree and credit mobility is important when considering the labour market outcomes of ISM and that personality does play a role in the links between degree mobility and labour market outcomes.
Environmental storage conditions influencing the filtration behavior of electret filters with repeated use

Worldwide attention has been paid to effective protection strategies against the COVID-19 pandemic. Filtering masks are generally kept for a certain period of shelf-life before being used, and frequently, they are used repeatedly with recurrent storages. This study investigates the effect of storage temperature and humidity on the structural characteristics and charges of an electret filter, associating with the filtration performance in terms of efficiency and pressure drop based on a practical use-storage scenario. For the repeated use conditions with recurrent storage, humid storage conditions significantly deteriorated the filtration efficiency as hygroscopic particles quickly wetted the surface and masked the surface charges. The high temperature rapidly deteriorated the filter charges and caused a lowered electrostatic filtration efficiency. In a heated condition, the web became fluffier, yet it did not directly affect the pressure drop or mechanical filtration efficiency. The approach of this study is progressive in that rigorous analysis was performed on examining the particle morphology and internal structure of filter media with varied storage conditions to link with the filtration performance and the effective lifetime. This study intends to provide a scientific reference guiding a desirable storage condition and replacement cycle of filtering masks considering the actual use habits and storage environment.
On The Fluid Dynamics Of Elliptic Cylinders

Aerodynamics of a set of two-dimensional stationary cylinders with eccentricity (e) in the range of 0.44 - 0.98 is studies experimentally during the organised wake condition. Extensive results are presented on static pressure distribution, Strouhal number and near-wake geometry as functions of the angle of attack with the Reynolds number in the range 3 x 104-105. Mean location of the separating shear layers is also obtained using the analytical Gortler series solution approach. Results suggest that the pressure loading as well as the wake characteristics are significantly affected by the cylinder eccentricity and attitude. In general, basing the Strouhal number on the projected width of the model appears to reduce its dependence on the angle of attack. An extensive scanning of the pressure field provides fundamental information concerning the vortex formation region, longitudinal and lateral spacing between the vortices, the classical wake geometry ratio, and vortex velocity. Extensive flow visualization study complements the wind tunnel test- program. The information should prove useful in the design of a variety of offshore structures including the oil-drilling platforms, energy conversion systems such as the OTEC, marine risers, and submarine detection systems.
Real‐time corrosion monitoring of an ultra‐high performance fibre‐reinforced concrete offshore raft by using an autonomous sensor system

The excellent high‐durability features of ultra‐high performance fibre‐reinforced concrete (UHPFRC) have been verified in laboratory studies, but its performance under service conditions are being studied. Indeed, structural health monitoring (SHM) can be considered an efficient strategy to assess built structures in which concrete matrix performance differs from that those found when assessing laboratory samples (variable actions, cracking, etc.). This work presents INESSCOM, an automated corrosion rate monitoring system, as an innovative support to SHM strategy to monitor UHPFRC structures in terms of durability. Its innovation lies in its durable and multi‐parametric sensor designed to be embedded in multiple parts of a structure. The results from previous laboratory tests and those obtained during real‐time monitoring of an offshore UHPFRC raft are presented. Acceptable deviation of 20% was obtained in corrosion rate measurements with the advantageous reference‐electrode‐free cell of the sensor with respect to the classical three‐electrode cell. Furthermore, sensor provided accurate corrosion measurements in UHPFRC despite its extremely high electrical resistivity and large amount of steel fibres. After 17‐month monitoring of the UHPFRC raft, excellent performance was evidenced under service conditions with corrosion rate values always <0.1 μA/cm2. Conversely, corrosion rate reached 0.4 μA/cm2 in a conventional concrete specimen installed for comparison. Corrosion initiation and propagation stages were clearly defined through the corrosion‐penetration‐damage (μm) diagram obtained for the specimen. Present work positions INESSCOM as an innovative support to structural health monitoring strategy in UHPFRC structures.
On the origin of the ultraviolet continuum emission from the high-redshift radio galaxy 3C 256

We report spectropolarimetric observations of the high-redshift ({ital z}=1.824) aligned radio galaxy 3C 256. Our observations confirm that the spatially extended UV continuum emission from this galaxy is polarized ({ital P}{sub {ital V}}{approx_equal}10.9{percent}{plus_minus}0.9{percent}) with the electric vector perpendicular to the aligned radio and optical major axes ({theta}{sub {ital V}}{approx_equal}48.0{degree}{plus_minus}2.4{degree}). This strongly suggests that a significant fraction of the rest frame UV continuum emission from the galaxy is not starlight, but is instead scattered light from a powerful active galactic nucleus that is hidden from our direct view. The narrow emission lines, including MgII, are unpolarized. The percentage polarization of the continuum emission and the polarization position angle are roughly constant as a function of wavelength. Although the present data do not permit us to discriminate between cool electrons and dust as the origin of the scattering, scattering by a population of hot ({ital T}{approx_gt}10{sup 7} K) electrons cannot be the dominant process, since such a population would overproduce X-ray emission. A large population of cooler electrons ({ital T}{approx_equal}10{sup 4} K) could be responsible for both the line emission and the scattered light, but would require that the dust-to-gas ratio in the scattering cones is 10{sup {minus}3} times smaller than that more » in our Galaxy and would imply that a large fraction of the baryonic mass in the galaxy is in the ionized component of its interstellar medium. Dust scattering is more efficient, but would result in detectable extinction of the emission-line spectrum unless the dust distribution is more highly clumped than the line emitting gas. Finally, we detect a strong ({ital W}{sup rest}{sub {lambda}}{approx_equal}12 A) broad (FWHM{approx_equal}6500 kms{sup {minus}1}) absorption line centered at {lambda}{sub rest}{approx_equal}1477 A. (Abstract Truncated) « less
STUDY ON THE EFFECT OF TWO DORMANCY BREAKING AGENTS ON ANNA APPLE TREES

The effect of (Dorcy 50% * ) and Buddy ** was studied on percentage of developing buds, diameter of fruits and fruit characters of Anna apple trees budded on MM.106 during two seasons of (1998-1999) and (1999-2000). Treatments of Dorcy 50% and Buddy separately or together accelerated bud burst comparing with untreated trees (control). Results were obtained treatments by Buddy 5%, Buddy 5% plus 0.5 % (Dorcy 50%) or 3 % (Dorcy 50%) showed increase in fruit set, in the two seasons of the experiment. The last three treatments caused an increase in fruit weight, size, diameter, and height. The treatments Buddy 5% and Buddy 5% plus 0.5 % (Dorcy 50%) gave highest value of total soluble solids, while control gave the lowest value. Untreated trees gave fruits with highest value of firmness and percentage of acidity, while fruits of trees treated with 3 % (Dorcy 50), and Buddy 5% alone or together were less in firmness and percentage of acidity.
Multi-wavelength landscape of the young galaxy cluster RXJ 1257.2+4738 at z = 0.866: II. Morphological properties

Studying the evolution of the morphological distribution of galaxies in different environments can provide important information about the effects of the environment and the physical mechanisms responsible for the morphological transformations. As part of a complete analysis of the young cluster RXJ 1257+4738 at z ~ 0.9, in this work we study the morphological properties of its galaxies. We used non-parametric methods of morphological classification, as implemented in the galSVM code. The classification with the applied method was possible even using ground-based observations, as the r ′-band imaging from OSIRIS/GTC. We defined very conservative probability limits, taking into account the probability errors, to obtain a trustworthy classification. In this way we were able to classify ~30% of all cluster members and to separate between late-type (LT) and early-type (ET) galaxies. Additionally, when analysing the colour-magnitude diagram, we observed a significant population of blue ET galaxies among the classified ones. We discussed possible explanations for finding this population. Moreover, we studied different physical properties of LT, ET, and blue ET galaxies. They turn out to be comparable, with the exception of the stellar mass that shows that the red ET population is more massive. We also analysed the morphology-density and morphology-radius relations observing that, only when considering the morphological separation between ET and LT galaxies, a mild classical behaviour is obtained. RXJ 1257+4738 is a young galaxy cluster, showing a clumpy structure, which is still in the process of formation, and which could explain the lack of some of the standard morphological relations. This makes this cluster a very attractive case for obtaining higher resolution data and for studying the morphological properties of the entire cluster in more detail and their relation to the environment.
Boundary Conditions for NHEK through Effective Action Approach

We study the asymptotic symmetry group (ASG) of the near horizon geometry of extreme Kerr black hole through the effective action approach developed by Porfyriadis and Wilczek (arXiv:1007.1031v1[gr-qc]). By requiring a finite boundary effective action, we derive a new set of asymptotic Killing vectors and boundary conditions, which are much more relaxed than the ones proposed by Matsuo Y et al. [Nucl. Phys. B 825 (2010) 231], and still allow a copy of a conformal group as its ASG. In the covariant formalism, the asymptotic charges are finite, with the corresponding central charge vanishing. By using the quasi-local charge and introducing a plausible cut-off, we find that the higher order terms of the asymptotic Killing vectors, which could not be determined through the effective action approach, contribute to the central charge as well. We also show that the boundary conditions suggested by Guica et al. [Phys. Rev. D 80 (2009) 124008] lead to a divergent first-order boundary effective action.
Prevalence, Antimicrobial Resistance, and Associated Factors of Streptococcus pneumoniae Colonization Rate among Old-Age Patients with Respiratory Tract Infection Attending Sheik Hassan Yebere Referral and Karamara General Hospitals, Jigjiga, Ethiopia

Background Streptococcus pneumoniae is part of the normal flora of the upper respiratory tract of humans. Colonization of the upper respiratory tract (carriage of pneumococcus) by S. pneumoniae is considered a prerequisite for pneumococcal infection. It is the major cause of respiratory tract infection and frequent cause of physician visits, hospitalization, and death among old-aged patients because of their low immunity status. However, data on S. pneumoniae among old-aged patients in eastern Ethiopia are limited. This study was undertaken to determine the prevalence, antimicrobial resistance, and associated factor of S. pneumoniae colonization among old-aged patients. Method A health facility-based cross-sectional study was conducted from 1 March to 15 April 2020, at Sheik Hassan Yebere Referral and Karamara General Hospitals, Jigjiga, eastern Ethiopia. A total of 188 individuals greater than or equal to 60 years suspected of both upper and lower respiratory tract infections were included. Sociodemographic, behavioral, living conditions, and clinical data were collected by trained data collectors. Sputum samples were collected and examined for S. pneumoniae using the culture and biochemical tests as per the standard procedures. The Kirby–Bauer disk diffusion method was used for antimicrobial susceptibility testing. The data were entered on Epi-data version 3.1, and frequencies, crude odds ratio, and adjusted odds ratio were analyzed using SPSS version 20. Results The prevalence of S. pneumoniae colonization rate among old-aged patients was 13.8% (26/188) (95% CI: 9.6–19.1). Smoking (AOR = 3.3; 95% CI: 1.3–8.3), upper airway problems (AOR = 4.1; 95% CI: 1.1–15), and asthma disease (AOR = 3.1; 95% CI: 1.1–8.9) were the factors associated with S. pneumoniae colonization. The isolated organisms showed high antimicrobial resistance to trimethoprim-sulphamethoxazole (n = 12, 46.2%), tetracycline (n = 11, 42.3%), and ampicillin (n = 9, 34.6%). Conclusion This study showed that high prevalence of S. pneumoniae and antimicrobial resistance for trimethoprim-sulphamethoxazole, tetracycline, and ampicillin when compared to similar studies. Cigarette smoking, having upper airway problem, and asthma disease were factors associated with S. pneumoniae colonization. The provision of pneumococci conjugate vaccination and avoiding smoking are highly recommended for old aged in the community.