Miracle-dz/UniFAR-FTUs huggingface dataset:
Efficient Tuning of the Opto-Electronic Properties of Sol–Gel-Synthesized Al-Doped Titania Nanoparticles for Perovskite Solar Cells and Functional Textiles

The efficient electron transport layer (ETL) plays a critical role in the performance of perovskites solar cells (PSCs). Ideally, an unobstructed network with smooth channels for electron flow is required, which is lacking in the pristine TiO2-based ETL. As a potential solution, here we tuned the structure of TiO2 via optimized heteroatom doping of Al. Different concentrations (1, 2, and 3 wt%) of Al were doped in TiO2 and were successfully applied as an ETL in PSC using spin coating. A significant difference in the structural, opto-electronic, chemical, and electrical characteristics was observed in Al-doped TiO2 structures. The opto-electronic properties revealed that Al doping shifted the absorption spectra toward the visible range. Pure titania possesses a bandgap of 3.38 eV; however, after 1, 2, and 3% Al doping, the bandgap was linearly reduced to 3.29, 3.25, and 3.18 eV, respectively. In addition, higher light transmission was observed for Al-doped TiO2, which was due to the scattering effects of the interconnected porous morphology of doped-TiO2. Al-doped titania shows higher thermal stability and a 28% lower weight loss and can be operated at higher temperatures compared to undoped titania (weight loss 30%) due to the formation of stable states after Al doping. In addition, Al-doped TiO2 showed significantly high conductivity, which provides smooth paths for electron transport. Thanks to the effective tuning of band structure and morphology of Al-doped TiO2, a significant improvement in current densities, fill factor, and efficiency was observed in PSCs. The combined effect of better Jsc and FF renders higher efficiencies in Al-doped TiO2, as 1, 2, and 3% Al-doped TiO2 showed 12.5, 14.1, and 13.6% efficiency, respectively. Compared to undoped TiO2 with an efficiency of 10.3%, the optimized 2% Al doping increased the efficiency up to 14.1%. In addition, Al-doped TiO2 also showed improvements in antibacterial effects, required for photoactive textiles.
Is the Role of Equations in the Doing of Word Problems in School Algebra Changing? Initial Indications From Teacher Study Groups

We illustrate a method, which is modeled on “breaching experiments,” for studying tacit norms that govern classroom interaction around particular mathematical content. Specifically, this study explores norms that govern teachers’ expectations for the doing of word problems in school algebra. Teacher study groups discussed representations of classroom interactions in which the class is doing a word problem and a student solves the word problem without writing an equation. Toulmin's scheme for everyday argumentation was adapted to analyze the study group talk. This analysis suggests that, for this sample, word problem norms are in flux; it may no longer be necessary for a student to state and solve an equation to do an algebra word problem. We propose that further research will have to determine whether the emerging change in these norms is attributable to policy initiatives in local contexts or whether it represents a larger cultural shift in conceptions of algebraic symbols.
Finite element analysis of pressure distortion coefficient and piston fall rate in a simple pressure balance

A finite element method (FEM) developed by the University of Cassino and the Istituto di Metrologia G. Colonnetti (IMGC, Turin) to optimize the design and use of simple pressure balances was applied while the most important operating and design parameters of the piston-cylinder units were varied. In particular, the influence of size, geometrical uncertainties and superficial roughness on the pressure distortion coefficient and on the piston fall rate was considered. Finally an analysis was carried out using the real clearance profile of the IMGC-100-NNtc unit based on dimensional measurements made at the IMGC. The comparison between the experimental values obtained at the IMGC and the numerical values, of both the pressure distortion coefficient and the piston fall rate, show excellent agreement.
Hydrodynamic Coefficients for In-Line Vortex Induced Vibrations

The paper presents results from an experimental investigation of hydrodynamic forces on a cylinder under forced in-line motions. Measured forces are decomposed into added mass, driving force and average drag components. From a large set of experiments it has been possible to draw a complete map for in-line force coefficients as function of arbitrary combinations of motion amplitude and frequency. The paper presents test set-up, data processing and how the coefficients can be used in an empirical force coefficient model for calculation of in-line vibrations of slender marine structures with arbitrary damping. Such analyses are in particular important for free spanning pipelines, where damping from pipe/seafloor interaction will reduce the response amplitudes and hence also stresses and fatigue damage.Copyright © 2007 by ASME
A Single-Layer Series-Fed SIW Slot Array Antenna Generating Two Orbital Angular Momentum Modes

A low-profile antenna capable of generating two coaxially propagating orbital angular momentum (OAM) modes is presented. It consists of two series-fed traveling-wave uniform circular arrays of sequentially rotated radiating slots and operates at 10 190 MHz. The smaller and larger radius arrays, with 4 and 8 radiating elements, produce OAM modes with indices lOAM = 0 and +1, respectively. They are designed using a unique simulation-based step-by-step technique and implemented on a single layer of the substrate-integrated waveguide, resulting in a simple structure. The antenna's performance is evaluated using simulations and measurements, with a high agreement between the results. Both modes work in left-hand circular polarization, with the first mode having a gain and axial ratio measured bandwidth of about 5.9 and 3.9%, respectively. In addition, the measured impedance bandwidth for the first and second modes is around 8.2 and 7.9%, correspondingly. Also, the orthogonality bandwidth of two identical antennas set 28 cm apart in front of each other is roughly 4.5%. The antenna's far-field and near-field radiation patterns are also investigated.
Population- and Gender-Based Investigation for Prevalence of Helicobacter pylori in Dhamar, Yemen

Among 35 species of genus Helicobacter, H. pylori is the most common causative agent of human gastritis, peptic ulcer, and gastric cancer. The infection can spread through direct human-to-human contact, fecal–oral route, and contaminated water. The study was designed to investigate the rate of prevalence of H. pylori in the population of Dhamar, Yemen. In this one-year study, 460 including 250 male and 210 female stool specimens were collected between January to December 2020 in Dhamar Governorate, Yemen. Of the total 460, 215 rural (male: n = 120 and female: n = 95) and 245 urban (male: n = 130 and female: n = 115) specimens were investigated for identification of H. pylori by serological test using Helicobacter pylori stool antigen (HpSA) test. In addition, for comparing an improved recovery of H. pylori, conventional culture-based isolation was also carried out using three selective media. Modified Campy-blood Agar (MCA), Belo Horizonte Agar (BHA), and Egg yolk Emulsion (EYE) medium supplemented with antimicrobial agents including vancomycin (10 mg/L), cefsulodin (5 mg/L), trimethoprim (5 mg/L), and amphotericin B (5 mg/L) and isolates were phenotypically characterized. The HpSA test results revealed that of the total 460 specimens, 89 (19.3%) were positive for H. pylori with relatively low in male (n = 43; 17.2%) as compared to the female (n = 46; 21.9%) specimens. After 3–10 days of incubation, H. pylori was recovered at a variable rate on each selective (MCA: 16.5%; BHA: 15.0%; EYE: 13.0%) media. However, culture-based assay results showed less recovery (n = 81; 17.6%) with no significant difference among all selective media tested and between genders (male: n = 39; 15.6%; female: n = 42; 20.0%). The infection rate was comparatively higher in rural (n = 45; 20.9%) as compared to urban (n = 36; 14.7%) population. Overall, the study data showed the prevalence of infection in both genders of all age groups. The present study showed a relatively high rate of infection of H. pylori in the Dhamar population. The serological identification and culture-based methods are important for rapid detection, aid in treatment, and developing policies for the control and eradication of H. pylori infection and to prevent the disease in different age groups in Yemen.
Evaluation of the Paradoxical Association Between Lipid Levels and Incident Atrial Fibrillation According to Statin Usage: A Nationwide Cohort Study

Objective Higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are associated with a lower risk of atrial fibrillation (AF). Statin use might exert confounding effects on the paradoxical associations; however, the relationships that distinguish statin users from non-users have not been thoroughly evaluated. Methods From the Korean National Health Insurance Database, we included 9,778,014 adults who underwent a health examination in 2009. The levels of TC and LDL-C at the health examination were categorized into quartile values of the total study population. We grouped the study population into statin users and non-users and investigated the associations between TC, LDL-C, and the risk of incident AF. Results Of the total population, 867,336 (8.9%) were taking statins. During a mean follow-up of 8.2 years, inverse associations of TC – AF and LDL-C – AF were observed; higher levels of TC and LDL-C were associated with the lower risk of AF in the total population. Overall, statin users showed higher AF incidence rate than non-users, but the inverse associations of TC – AF and LDL-C – AF were consistently observed irrespective of statin usage; adjusted hazard ratio with 95% confidence interval was 0.81 (0.79–0.84) for statin users and 0.81 (0.80–0.83) for non-users in the highest TC quartile, and 0.84 (0.82–0.87) for statin users and 0.85 (0.84–0.86) for non-users in the highest LDL-C quartile (all p<0.001). Conclusion The paradoxical relationship between lipid levels (TC and LDL-C) and the risk of AF remains consistent in both statin users and non-users.
UVCS/SOHO investigation of the interface between streamers and coronal holes

We investigated the properties of the interface between streamers and coronal holes at low heliocentric distances, observing the extended solar corona in the North-West quadrant by UVCS/SOHO. We measured the line profiles of the H  Lyα and O  resonance doublet and the visible linearly polarized radiance at heliocentric distances ranging from 1.4 to 2.5 R� , and colatitudes spanning from the North pole to the West equator with steps of ∼10 ◦ . The results show that both the line intensities and the line widths, in particular those of O , exhibit sharp variations across the streamer boundaries, with a clear anticorrelation between intensities and widths. We also notice a positive correlation for Lyα in the region close to the equator. The steep changes in O  line profiles occur in a narrow transition region (5 ◦ −10 ◦ ), right at the borders of the streamers, from 1.5 Ronwards. The O  resonance doublet line ratio steeply increases outside of the streamer as well, but this occurs at higher heliocentric distances (above 2 R� ). Hence the marked broadening of the O  lines and the considerable rise of their intensity ratio are an evident signature of the transition from closed to open field lines in streamer magnetic field topologies. This behaviour also implies that a strong and preferential non-thermal heating of O  ions in the direction coinciding with the line of sight and the turn-on of a significant outflow occur in the open magnetic field region near or just outside of the streamer edges.
Dual Infection of Hepatitis A Virus and Hepatitis E Virus— What Is Known?

Viral hepatitis is an infection of human hepatocytes resulting in liver damage. Dual infection of two hepatotropic viruses affects disease outcomes. The hepatitis A virus (HAV) and hepatitis E virus (HEV) are two enterically transmitted viruses; they are single-stranded RNA viruses and have common modes of transmission. They are transmitted mainly by the fecal-oral route and ingestion of contaminated food, though the HAV has no animal reservoirs. The HAV and HEV cause acute self-limiting disease; however, the HEV, but not HAV, can progress to chronic and extrahepatic infections. The HAV/HEV dual infection was reported among acute hepatitis patients present in developing countries. The impact of the HAV/HEV on the prognosis for acute hepatitis is not completely understood. Studies showed that the HAV/HEV dual infection increased abnormalities in the liver leading to fulminant hepatic failure (FHF) with a higher mortality rate compared to infection with a single virus. On the other hand, other reports showed that the clinical symptoms of the HAV/HEV dual infection were comparable to symptoms associated with the HAV or HEV monoinfection. This review highlights the modes of transmission, the prevalence of the HAV/HEV dual infection in various countries and among several study subjects, the possible outcomes of this dual infection, potential model systems for studying this dual infection, and methods of prevention of this dual infection and its associated complications.
Turbulent coagulation of colloidal particles

Theoretical predictions for the coagulation rate induced by turbulent shear have often been based on the hypothesis that the turbulent velocity gradient is persistent (Saffman & Turner 1956) and that hydrodynamic and interparticle interactions (van der Waals attraction and electrostatic double-layer repulsion) between colloidal particles can be neglected. In the present work we consider the effects of interparticle forces on the turbulent coagulation rate, and we explore the response of the coagulation rate to changes in the Lagrangian velocity gradient correlation time (i.e. the characteristic evolution time for the velocity gradient in a reference frame following the fluid motion). Stokes equations of motion apply to the relative motion of the particles whose radii are much smaller than the lengthscales of turbulence (i.e. small particle Reynolds numbers). We express the fluid motion in the vicinity of a pair of particles as a locally linear flow with a temporally varying velocity gradient. The fluctuating velocity gradient is assumed to be isotropic and Gaussian with statistics taken from published direct numerical simulations of turbulence (DNS). Numerical calculations of particle trajectories are used to determine the rate of turbulent coagulation in the presence and absence of particle interactions. Results from the numerical simulations correctly reproduce calculated coagulation rates for the asymptotic limits of small and large total strain where total strain is a term used to describe the product of the characteristic strain rate and its correlation time. Recent DNS indicate that the correlation times for the fluctuating strain and rotation rate are of the same order as the Kolmogorov time (Pope 1990), suggesting theories that assume either small or large total strain may poorly approximate the turbulent coagulation rate. Indeed, simulations for isotropic random flows with intermediate total strain indicate that the coagulation rate in turbulence is significantly different from the analytical limits for large and small total strain. The turbulent coagulation rate constant for non-interacting monodisperse particles scaled with the Kolmogorov time and the particle radius is 8.62±0.02, whereas the commonly used model of Saffman & Turner (1956) predicts a value of 10.35 for non-rotational flows in the limit of persistent turbulent velocity gradients. Additional simulations incorporating hydrodynamic interactions and van der Waals attraction were used to estimate the actual rate of particle coagulation. For typical values of these parameters, particle interactions reduced the coagulation rate constant by at least 50%. In general, the collision efficiency (the ratio of coagulation with particle interactions to that without) decreased with increasing particle size and Kolmogorov shear rate.
AN AXIOMATIC APPROACH TO MEASURABLE UTILITY

Abstract : Previous treatments of this approach brought topological considerations of the prospects space into the axioms. In this paper considerations of the topology of the prospect space itself are removed, the previous axioms are weakened an infinite number of sure prospects are allowed. On the basis of these axioms the existence of a measurable utility is established.
Kulikov's Problem on Universal Torsion‐Free Abelian Groups

Let T be an abelian group and λ an uncountable regular cardinal. The question of whether there is a λ‐universal group U among all torsion‐free abelian groups G of cardinality less than or equal to λ satisfying Exta(G,T) = 0 is considered. U is said to be λ‐universal for T if, whenever a torsion‐free abelian group G of cardinality at most λ satisfies Ext(G,T)=0, there is an embedding of G into U. For large classes of abelian groups T and cardinals λ, it is shown that the answer is consistently no, that is to say, there is a model of ZFC in which, for pairs T and λ, there is no universal group. In particular, for T torsion, this solves a problem by Kulikov.
FE Modeling of Human Vocal Tract Acoustics. Part II: Influence of Velopharyngeal Insufficiency on Phonation of Vowels

Developed FE models of acoustic spaces of nasal and vocal tract for vowels /u:/, /a:/ and /i:/ are used to study the influence of velofaryngeal insufficiency on phonation of these vowels. Acoustics frequency-modal characteristics are studied by modal analysis and numerical simulation of acoustic signals in time domain is performed by transient analysis of the FE models. The vocal tract is excited by time dependent airflow at the position of vocal folds, and the time and frequency responses are calculated near the lips and nose. The theoretical results are partly compared with acoustic measurements on physical models designed by the rapid prototyping technique from the FE models, and by clinical investigation.
Stable 2 MW, 35 GHz, third-harmonic TE/sub 41/ gyro-TWT amplifier

A third-harmonic gyro-TWT amplifier operating in the TE/sub 41/ mode is described that is predicted to generate 2 MW at 35 GHz. The device is based on the proven concept that the electron beam current can be significantly higher in a stable harmonic gyro-TWT amplifier than at the fundamental due to the comparatively weaker harmonic interaction. For stability, the circuit is sliced to suppress electromagnetic modes without the desired symmetry and the 100 kV, 100 A electron beam from a magnetron injection gun is placed at the null of the strongest remaining gyro-BWO mode. The single-stage gyro-TWT is predicted to produce 2 MW with 20% efficiency, 30 dB saturated gain and 3.5% constant-drive bandwidth.
Characterization and analysis of InAs/p–Si heterojunction nanowire-based solar cell

The growth of compound semiconductor nanowires on the silicon platform has opened many new perspectives in the area of electronics, optoelectronics and photovoltaics. We have grown a 1 × 1 mm2 array of InAs nanowires on p-type silicon for the fabrication of a solar cell. Even though the nanowires are spaced by a distance of 800 nm with a 3.3% filling volume, they absorb most of the incoming light resulting in an efficiency of 1.4%. Due to the unfavourable band alignment, carrier separation at the junction is poor. Photocurrent increases sharply at the surrounding edge with the silicon, where the nanowires do not absorb anymore. This is further proof of the enhanced absorption of semiconductors in nanowire form. This work brings further elements in the design of nanowire-based solar cells.
The Neutral Interstellar Medium in Nearby Dwarf Galaxies. III. Sagittarius DIG, LGS 3, and Phoenix

We present new VLA observations of the H I medium of the Local Group dwarf galaxies Sag DIG, LGS 3, and Phoenix. Sag DIG is a gas-rich, blue dwarf irregular with some known recent star formation, whereas LGS 3 and Phoenix are gas-poor, red galaxies of intermediate irregular/spheroidal type with little recent star formation. These galaxies complete a small sample of Local Group and near-Local Group irregular and elliptical galaxies that have been mapped in H I and, where possible, in CO. We compare the properties and kinematics of the ISM in these different galaxy types in order to gain some insights into the relationship between galaxy properties, star formation, and the ISM. Both Sag DIG and LGS 3 have larger H I extents and higher H I fluxes than previously known, and in both cases the H I extends significantly farther than the stellar component. Neither one shows convincing signs of rotation; both seem to derive a significant amount of their support against gravity from random motions in the gas. The dwarf galaxies of the sample support the idea that there are large variations in the dark/luminous mass ratio at a given luminosity. The high sensitivity and high spectral and spatial resolution of these observations also make it possible to study the physical properties of the H I medium. The H I in Sag DIG is decomposed into broad (σ = 10 km s-1) and narrow (σ = 5 km s-1) components, with the broad component distributed throughout the galaxy and the narrow component concentrated into a small number of prominent clumps of about 8 × 105 M☉. It is argued that these H I components are in fact cold and warm phases of the H I medium, as in Galactic H I and in the dwarf irregular Leo A. LGS 3, on the other hand, shows little sign of such a two-phase H I structure. This new information on the phase structure of the ISM in dwarf galaxies is consistent with theoretical models of the H I medium if the H I line width is greater than purely thermal widths. The lack of a cold H I phase may be a reason for the lack of recent star formation in LGS 3; we suggest that the presence of a cold H I phase serves as a better indicator of conditions appropriate for star formation than measures of total H I content. The Phoenix dwarf and LGS 3 have been interpreted as two dwarf spheroidal galaxies which are unusual in that they contain H I. The presence of H I in LGS 3 is interesting, then, in the context of models that remove the gas from dwarf spheroidals by a burst of star formation. Either LGS 3 has not had a burst of star formation sufficient to remove its gas, or gas removal was not complete. It is not clear whether the Phoenix dwarf has H I. The current observations show emission in the vicinity of the galaxy at +55 km s-1 and -23 km s-1 (heliocentric). However, none of this emission is coincident with the optical galaxy. Until the stellar velocities in Phoenix are known, we cannot distinguish whether any of the detected H I is actually associated with the galaxy or is perhaps associated with the Magellanic Stream.