Miracle-dz/UniFAR-FTUs huggingface dataset:
Which effective viscosity?

Abstract Magmas undergoing shear are prime examples of flows that involve the transport of solids and gases by a separate (silicate melt) carrier phase. Such flows are called multiphase, and have attracted much attention due to their important range of engineering applications. Where the volume fraction of the dispersed phase (crystals) is large, the influence of particles on the fluid motion becomes significant and must be taken into account in any explanation of the bulk behaviour of the mixture. For congested magma deforming well in excess of the dilute limit (particle concentrations >40% by volume), sudden changes in the effective or relative viscosity can be expected. The picture is complicated further by the fact that the melt phase is temperature- and shear-rate-dependent. In the absence of a constitutive law for the flow of congested magma under an applied force, it is far from clear which of the many hundreds of empirical formulae devised to predict the rheology of suspensions as the particle fraction increases with time are best suited. Some of the more commonly used expressions in geology and engineering are reviewed with an aim to home in on those variables key to an improved understanding of magma rheology. These include a temperature, compositional and shear-rate dependency of viscosity of the melt phase with the shear-rate dependency of the crystal (particle) packing arrangement. Building on previous formulations, a new expression for the effective (relative) viscosity of magma is proposed that gives users the option to define a packing fraction range as a function of shear stress. Comparison is drawn between processes (segregation, clustering, jamming), common in industrial slurries, and structures seen preserved in igneous rocks. An equivalence is made such that congested magma, viewed in purely mechanical terms as a high-temperature slurry, is an inherently nonequilibrium material where flow at large Pe´clet numbers may result in shear thinning and spontaneous development of layering.
Development of Micro Separation Technology Modules. Part 2: Distillation

The subject of previous work on liquid-liquid extraction is complemented in this paper through the research activities in micro distillation. After a detailed literature study comparing the performance, strengths, and weaknesses of published micro distillation methods, critical process parameters based on model studies will be discussed. Apparative approaches to micro distillation are presented, where the capillary module used for distillation can provide a successful phase separation of gas-liquid mixtures up to volume feeds of 10 mL min−1.
The two-phase gas outflow in the Circinus Galaxy

Abstract We employ Multi Unit Spectroscopic Explorer (MUSE) data to study the ionized and very ionized gas phase of the feedback in Circinus, the closest Seyfert 2 galaxy. The analysis of the nebular emission allowed us to detect a remarkable high-ionization gas outflow, out of the galaxy plane, traced by the coronal lines [Fe viii] 6089Å and [Fe x] 6374Å, extending up to 700 parsecs north-west from the nucleus. The gas kinematics reveal expanding gas shells with velocities of a few hundred km s-1, spatially coincident with prominent hard X-ray emission detected by Chandra. Density and temperature sensitive line ratios show that the extended high-ionization gas is characterized by a temperature of up to 18000 K and a gas density of ne > 102 cm−3. We propose two scenarios consistent with the observations to explain the high-ionization component of the outflow: an active galactic nuclei (AGN) ejection that took place ⁓105 yr ago or local gas excitation by shocks produced by the passage of a radio jet.
Nuclear Star Clusters in Coma confirmation of an unusually high nucleation fraction

Abstract Nuclear star clusters (NSCs) are stellar systems similar in size to globular clusters (GCs) but extremely dense, comparable only to some GCs and ultra-compact dwarfs. They are present in galaxies with a wide range of masses, morphologies and gas content. There are several formation scenarios proposed for the formation of such objects, such as the merger of GCs or extreme star formation caused by the inflow of gas. Recent studies show that the presence of an NSC is related to galaxy stellar mass. Moreover, it has been suggested that NSCs are more often found in high density environments. In our work, we use deep imaging of the core regions of the Coma cluster down to an absolute magnitude of –8.2 and found that in this environment the nucleation fraction is higher than in the Virgo and Fornax clusters. We find nucleated galaxies in Coma as faint as –11.2 mag.
High-resolution mass spectrometry method for the analysis of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone in waters

A method was developed for the analysis of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) in drinking waters that is based on electron-ionization high-resolution mass spectrometry and selected-ion monitoring of the m/z 199 and 201 ions of the methyl derivative of MX and the use of isotopically labeled benzoic acid as the internal standard. High-resolution mass spectrometry is needed to provide sensitivity, selectivity, and confidence in the identification of MX in water extracts. In the analysis of matrix spikes and replicate samples, the method provided recoveries of 102-108% and a precision of 8% RSD
The near-field aerodynamic characteristics of hot high-speed jets

Abstract Motivated by design challenges related to aerospace propulsive jets, an experimental investigation has been conducted of the high Mach number jet plume flow field from a round convergent nozzle at under-expanded shock-containing conditions. Hot jets up to a total temperature ratio of 3 were considered. Laser doppler anemometry (LDA) measurements in the jet near field (first 15 nozzle exit diameters) captured the turbulent mixing process in detail, enabling the separate effects of compressibility and static temperature ratio (t) on the development of the velocity and turbulence profiles to be identified. Compressibility dominated in the initial shear layer region, whereas temperature effects controlled the downstream jet merging zone. Analysis of shear layer development demonstrated that, at all temperature ratios, a similar, but significantly stronger, damping effect was observed as in planar shear layers (correlated well by convective Mach number Mc). Consideration of the interaction of compressibility and temperature ratio – which reduce/enhance turbulent mixing respectively – provided for the first time a rational explanation of the observation that increasing jet temperature influenced flow development only up to a static temperature ratio t ~ 1.5, after which further increase has little effect. Measurements of the potential core length (Lp) were analysed to produce an empirical correlation that also illustrated the diminishing effects of heat addition at all jet Mach numbers. The data provide the improved understanding and empirical design techniques essential for developing technologies for jet noise and infra red (IR) signature reduction and represent an important validation test case for computational fluid dynamics (CFD) modelling.
Bayesian Methods for Ion Selective Electrodes

With the increasing use of ion-selective electrodes in environmental and health applications, it is important to know the precision of estimated concentrations. A Bayesian model for non-linear calibration is introduced which provides estimates of measurement precision by incorporating uncertainty in calibration parameters and inherent random noise in emf response. The analysis of lead in 17 soil samples demonstrates that large gains in precision are possible when calibrations are extended to include multiple electrodes and standard addition data. The results highlight the need for improved calibration and routine use of standard addition as ion selective electrodes become increasingly popular for demanding, real world applications.
DOUBLE DIFFUSIVE MAGNETO- MARANGONI CONVECTION IN A COMPOSITE LAYER

The Hydrothermal growth of crystals is mathematically modeled as the onset of double diffusive magneto-marangoni convection in a two-layer system comprising an incompressible two component, electrically conducting fluid saturated porous layer over which lies a layer of the same fluid in the presence a vertical magnetic field. The upper boundary of the fluid layer is made free at which act the surface tension effects depending on both the temperature and species concentration and the lower boundary of the porous layer is rigid. Both the boundaries are insulating to both heat and mass. At the interface the velocity, shear stress, normal stress, heat, heat flux, mass and mass flux are assumed to be continuous conducive for Darcy-Brinkman model. The resulting eigenvalue problem is solved by regular perturbation technique. The critical thermal Rayleigh number, which is the criterion for stability of the system is obtained. The effects of different physical parameters on the onset of double diffusive magneto-marangoni-convection are investigated in detail which enables to control convection during the growth of crystals in order to obtain pure crystals.
Surfactant Effect on Oxide-to-Nitride Removal Selectivity of Nano-abrasive Ceria Slurry for Chemical Mechanical Polishing

Through a chemical mechanical polishing (CMP) test using oxide and nitride blanket film wafers, we investigated the effect of adding an anionic surfactant to a ceria slurry, especially at very dilute concentrations (less than 0.2 wt%). The removal rate trend, which decreases with increasing surfactant concentration, was compared with the variation in the electrokinetic behavior of the ceria abrasives dispersed in the slurry. The removal rate transition did not coincide with the changes in the zeta potential or the secondary particle size distribution of the abrasives. This suggests that the electrostatic effect is not the dominant factor in the removal rate with ceria slurry. It is also found that abrasive size influences removal rate trend versus surfactant concentration, and that oxide removal follows Preston's law but nitride removal shows non-Prestonian behavior. To explain the result qualitatively, we have proposed a hydrodynamic model in which a particle travels through the viscous fluid and approaches the film surface.
3-D Electron Crystallography Reveals the “Off” State of Smooth Muscle Myosin.

The activity of myosin II from vertebrate smooth and non-muscle cells is controlled by phosphorylation of the regulatory light chain (RLC). Smooth muscle heavy meromyosin (HMM) is a truncated double-headed myosin molecule that is soluble at physiological ionic strength. Subfragments of myosin containing two heads retain phosphorylation dependent regulation but single headed subfragments do not and are always “In”(Cremo et al., 1995; Trybus et al., 1997) thereby implicating head-head interactions as a fundamental feature of regulation. We have used a positively charged lipid monolayer to obtain 2-D crystalline arrays of both the unphosphorylated, inactive form (I-form) and thiophosphorylated, activated form (P-form) from chicken gizzard smooth muscle HMM obtained from a Baculovirus expression system. A comparison of averaged 2-D projections of both forms in negative stain at 2.3 nm resolution reveals distinct structural differences (Wendt et al., 1999). The two crystals have p2 symmetry but vastly different unit cell dimensions.
Time-dependent atmospheric CO2 inversions based on interannually varying tracer transport

The use of inverse calculations to estimate surface CO2 fluxes from atmospheric concentration measurements has gained large attention in recent years. The success of an inversion will, among other factors, depend strongly on how realistically atmospheric tracer transport is represented by the employed transport model, as it links surface CO2 fluxes to modelled concentrations at the location of measurement stations. We present sensitivity studies demonstrating that transport modelling should be based on interannually varying meteorology, as compared to the traditional use of repeating a single year’s winds only. Moreover, we propose an improved procedure of representing the concentration sampling in the model, which allows consistency with the measurements and uses their information content more efficiently. In further sensitivity tests, we estimate the effect of different spatial transport model resolutions and different meteorological driver data sets. Finally, we assess the quality of the inversion results with the help of independent measurements and flux estimates, and preliminarily discuss some of the resulting features.
One‐Step Electrochemical Synthesis of Graphene/Polyaniline Composite Film and Its Applications

This work describes a new one‐step large‐scale electrochemical synthesis of graphene/polyaniline (PANI) composite films using graphite oxide (GO) and aniline as the starting materials. The size of the film could be controlled by the area of indium tin oxide (ITO). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible absorption spectrum (UV–vis) results demonstrated that the graphene/PANI composite film was successfully synthesized. The obtained graphene/PANI composite film showed large specific area, high conductivity, good biocompatibility, and fast redox properties and had perfect layered and encapsulated structures. Electrochemical experiments indicated that the composite film had high performances and could be widely used in applied electrochemical fields. As a model, horseradish peroxidase (HRP) was entrapped onto the film‐modiﬁed glassy carbon electrode (GCE) and used to construct a biosensor. The immobilized HRP showed a pair of well‐deﬁned redox peaks and high catalytic activity for the reduction of H2O2. Furthermore, the graphene/PANI composite film could be directly used as the supercapacitor electrode. The supercapacitor showed a high specific capacitance of 640 F g−1 with a retention life of 90% after 1000 charge/discharge cycles.
Facile bulk production of highly blue fluorescent graphitic carbon nitride quantum dots and their application as highly selective and sensitive sensors for the detection of mercuric and iodide ions in aqueous media

Highly blue fluorescent graphitic carbon nitride quantum dots (g-CNQDs) were synthesized by a simple microwave mediated method from formamide (HCONH2). The fluorescence emission of g-CNQDs is found to be strongly dependent on solvent, pH as well as on excitation wavelengths; the life time of the emission decreases with increasing polarity of the solvent. These quantum dots are highly sensitive and selective florescent probes for mercuric ions in aqueous media due to the “superquenching” of fluorescence. The complex formation of Hg2+ ions with the CNx sheet involving π delocalized electron moieties of the latter, in fact, is responsible for the quenching of fluorescence. The addition of iodide ions abstracts the bound Hg2+ forming HgI2 and gives back the fluorescence characteristic of g-CNQDs. Thus, g-CNQDs can play a dual role for selective and sensitive detection of mercuric ions as well as iodide ions in aqueous media via “ON–OFF–ON” fluorescence response.
Electron and hole mobilities in inversion layers on thermally oxidized silicon surfaces

Extensive measurements of electron and hole mobilities in inversion layers on thermally oxidized silicon surfaces were performed using the field effect conductance technique. It was found that both electron and hole mobilities are practically constant and approximately equal to one half of their respective bulk values up to a surface field of about 1.5 × 105volts/cm, corresponding to about 1012electronic charges/cm2induced in the silicon. At higher fields the inversion layer mobilities begin to decrease slightly. The temperature dependence of inversion layer mobilities follows a T-1.5rule at the upper range of the interval -196 to 200°C, indicating a scattering mechanism similar to lattice scattering. This observation is further supported by the lack of a significant effect of an order-of-magnitude variation in the bulk impurity concentration (1015- 1016cm3) on the inversion layer mobilities. No significant effect of structural and geometrical parameters (such as channel length and shape, oxide type and thickness, and surface charge density) was found on the inversion layer mobilities.
Radio galaxies with and without emission lines

Abstract Using the recent ROGUE I catalogue of galaxies with radio cores (Kozie_l-Wierzbowska et al. 2020) and after selecting the objects which are truly radio active galactic nuclei, AGNs, (which more than doubles the samples available so far), we perform a thorough comparison of the properties of radio galaxies with and without optical emission lines (galaxies where the equivalent width of Hα is smaller than 3Å are placed in the last category). We do not find any strong dichotomy between the two classes as regards the radio luminosities or black hole masses. The same is true when using the common classification into high- and low-excitation radio galaxies (HERGs and LERGs respectively).
Gauging the effect of feedback from QSOs on their host galaxies

Abstract Often associated with the regulation of star formation in galaxies, active galactic nuclei (AGN) play a fundamental role in the evolution of galaxies through their feedback effects. To investigate the impact of these effects, we analysed the optical emission-line properties of 8 type II AGNs with bolometric luminosities LBol > 1045 erg s−1, using integral field spectroscopy (IFS) observations with Gemini Multi-Object Spectrograph (GMOS). The gas kinematics was obtained by fitting Gaussian components to the profiles of the emission lines of the ionized gas. Using only the broadest component – that we associate with the gas in outflow – we calculated the mass outflow rate (Ṁout), finding values of up to 10 M⊙ yr−1. The outflow kinetic power (Ėout reaches maximum values between 1041 and 1043 erg s−1, which correspond to feedback efficiencies of ∼0.001−0.1 % of Lbol. These values are below that required to quench the star formation during the evolution of galaxies in simulations and analytical models. We also investigated the effect of uncertainties on the values of the physical quantities used in the calculations – such as the electron density – on the final values of Ṁout and Ėout.
Cosmic magnetism evolution using cosmological simulations

Abstract The Intergalactic Medium (IGM) is the region comprising the environment between the galaxies. Gamma-ray observations have provided lower limits to IGM magnetic fields of the order of ≳10–16 G. Magnetic fields are continuously ejected from galaxies by jets and galactic winds. However, the origin and evolution of cosmic magnetic fields in the more diffuse regions, like voids, is still debated. The difficulties in directly measuring magnetic fields and their coherent scales, make hydrodynamic and magnetohydrodynamic (MHD) cosmological simulations useful tools to shed light on this debate. As a first approach, we have performed hydrodynamic cosmological simulations assuming energy equipartition as an initial condition between the baryonic gas and the magnetic field, starting at z = 8, to track the evolution of magnetic fields, and compare with results of MHD simulations. We have found that for halos and cores, our results are comparable to the MHD description. For the less dense regions, the equipartition condition clearly overestimates the observed limits. In forthcoming work, we will investigate MHD simulations of cosmological evolution and amplification of seed magnetic fields, considering all relevant feedback processes and exploring turbulent dynamo amplification versus primordial mechanisms across cosmological timescales.
Overlap and resource sharing in coteries of fruit-eating birds

Abstract: A range of species eating the same fruit suggests that niche overlap can occur, along with potential competition among them. To test if the overlap in the coterie of fruit-eating birds is larger than would be expected by chance, we performed a comparison with coteries generated from the use of null models. The study was carried out in an area of savanna woodland of 127 ha in Uberlândia city, Brazil. Four individuals of five zoochorous plant species were selected and 60 h of focal observation was performed on each species. We recorded species of birds that consumed fruits and the quantity of fruit removed. We used an index of Proportional Similarity (PS) between each pair of plant species, using the relative proportion of fruit taken by each bird species of each plant. The mean value of observed PS was compared with the mean PS generated from randomizations. Thirty-six bird species were recorded eating fruits in the selected plant species. The mean overlap observed (PS = 0.183) was significantly higher (P = 0.032) than the mean overlap generated by the null models (PS = 0.123). This pattern suggests that competition is not an important factor in the formation of the coteries and there is sharing of resources. The abundance of fruits offered, especially in the rainy season, and the relatively low number of frugivorous species may be factors explaining the low influence of interactions and therefore the overlap between coteries.
Dual Fluorescence from Two Polar Excited States in One Molecule. Structurally Additive Photophysics of Crystal Violet Lactone

Crystal violet lactone (CVL) emits in aprotic solvents at room temperature single (A band, low polar solvents) or dual (A and B bands, medium and highly polar solvents) fluorescence. Strong solvatochromic shifts of both fluorescence bands prove significant charge redistribution in both emitting states (1CTA and 1CTB). Comparison with model compounds mimicking structural subunits of CVL, 6-dimethylaminophthalide (6-DMAPd), and malachite green lactone (MGL) shows that the A band is displayed from a polar excited state localized within the 6-DMAPd subunit (1CTA, μe ≅ 10.7 D), and the B band, from a highly polar excited state (1CTB, μe ≅ 25.2 D) formed after electron transfer from one of the dimethylaniline groups to 6-DMAPd moiety. The 1CTB state becomes accessible and is populated during solvation by a sufficiently polar environment. CVL phosphorescence strictly matches that of 6-DMAPd, indicating ISC to a triplet state localized on 6-DMAPd moiety in low polar solvents. In polar solvents, transient absorpti.
Decontamination of ofloxacin: optimization of removal process onto sawdust using response surface methodology

AbstractOfloxacin is one of the most used fluoroquinolones, a potent broad spectrum antibiotic class; it is also included in pharmaceutically active compounds that are considered as environmental pollutants. To clean the water systems sorption has been found as an effective way to remove these pollutants. Present study demonstrates the effect of different sawdust treatments on removal of ofloxacin from aqueous solutions. The sorption of ofloxacin by treated sawdust has been optimized by response surface methodology using central composite design. Set of 18 experiments was used and factors as pH, amount of sorbent, contact time, and concentration of sorbate were considered the critical factors to be studied for removal. HCl-treated sawdust was found to have maximum removal efficiency (96%) with the sorption capacity of 47 μmol g−1 as compared to other treated sorbents. Amount of sorbent have significantly positive impact on the removal for all three treated sorbents whereas concentration of sorbate has non.