Miracle-dz/UniFAR-FTUs huggingface dataset:
A Theory for Nonprecipitating Moist Convection between Two Parallel Plates. Part I: Thermodynamics and “Linear” Solutions

Abstract A defining feature of moist convection is latent heating. A simple, mathematically tractable but thermody-namically reasonable Kuo-type model is developed to isolate some important effects of latent heating on the structure and organization of moist convection. Convection in a shallow, unsheared layer of viscous moist air between two rigid horizontal plates is examined. Unlike previous analytical work, a realistic thermodynamic equation is used, based on the assumption that no precipitation falls out of saturated air. This assumption isolates reversible latent heating from the complicating effects of precipitation. The crucial step is to express the buoyancy of moist air as a simple function of adiabatically conserved, linearly mixing properties of the air; this function is different in saturated than in unsaturated air. In Part I, the new model is used to find analytical solutions for infinitesimal motions in a conditionally unstable, exactly saturated atmosphere. As in previous work, the most u.
LS‐DYNA and the 8:1 differentially heated cavity

This paper presents results computed using LS‐DYNA's new incompressible flow solver for a differentially heated cavity with an 8:1 aspect ratio at a slightly super‐critical Rayleigh number. Three Galerkin‐based solution methods are applied to the 8:1 thermal cavity on a sequence of four grids. The solution methods include an explicit time‐integration algorithm and two second‐order projection methods—one semi‐implicit and the other fully implicit. A series of ad hoc modifications to the basic Galerkin finite element method are shown to result in degraded solution quality with the most serious effects introduced by row‐sum lumping the mass matrix. The inferior accuracy of a lumped mass matrix relative to a consistent mass matrix is demonstrated with the explicit algorithm which fails to obtain a transient solution on the coarsest grid and exhibits a general trend to under‐predict oscillation amplitudes. The best results are obtained with semi‐implicit and fully implicit second‐order projection methods where the fully implicit method is used in conjunction with a ‘smart’ time integrator. Copyright © 2002 John Wiley & Sons, Ltd.
DNS study on viscoelastic effect in drag-reduced turbulent channel flow

The effect of viscoelastic contribution on wall-bounded turbulent flow of drag-reducing surfactant solution is investigated through direct numerical simulations (DNS). A series of DNS on turbulent channel flow is performed for different rheological properties at two different Reynolds numbers. It is found that high drag reduction is achieved by suppressing the turbulent contribution for the high Weissenberg number, and/or by decreasing the viscosity ratio and the effective viscosity. A highly drag-reduced turbulent flow at a high Reynolds number is mainly caused by the viscoelastic effect in the elastic layer, whereas the outer layer flow hardly affects the drag reduction. Moreover, we focus on the viscoelastic contribution term in the budget of Reynolds stress and its relation to the local flow pattern. It is shown that in the near-wall region of the highly drag-reduced flow a positive work done by viscoelastic stress is closely associated with vortex stretching that produces turbulent kinetic energy from stored elastic energy, whereas a negative one causes vortex compression.
PREFERENCE FOR VIDEOGAMES AND ITS CORRELATIONS WITH MORAL DISENGAGEMENT, PERSONALITY TRAITS AND ACADEMIC ACHIEVEMENT IN ITALIAN PRE-ADOLESCENTS

The aim of this study is to explore the existing relationship between gameplay type and moral disengagement, personality traits, and academic achievement. For this purpose, a sample of Italian pre-adolescents (N=363; males 48.5%, mean age=10.02, SD=1.15) was recruited. Participants completed a self-report questionnaire including data regarding sociodemographic data, play practices, and the following psychological tests: Big Five Questionnaire-Children; Moral Disengagement Evaluation Scale. Results suggest that preference for videogames was statistically associated with moral disengagement but it was not associated with personality traits nor with academic achievement. Outdoor play was associated with academic achievement and with a series of personality traits that are usually negatively connected to problematic gambling. The preference for videogames in pre-adolescence seems to have more influence on the moral disengagement than on the personality traits or academic achievement. Instead, outdoor play resulted as a protection factor for academic achievement and the onset of personality traits that could predispose the child to problematic gameplay in the future.
Perturbation of the northern hemisphere radiative balance by backscattering from anthropogenic sulfate aerosols

Anthropogenic sulfate (SO 4 = ) aerosol particles play two potential roles in the radiative climate of the earth. In cloud-free air, SO 4 = particles scatter sunlight, some of which is lost to space, thereby reducing solar irradiance at the ground. The same particles can act as cloud condensation nuclei (CCN), the number concentration of which is an important determinant of cloud albedo. This albedo effect, in turn, also influences incoming short-wave solar radiation. Development of a three-dimensional global model for estimating the SO 4 = aerosol mass concentration, along with previously-acquired information on the scattering and back-scattering coefficients per unit mass concentration allow calculation of the effects of anthropogenic SO 4 = aerosol on clear-sky optical depth. Subsequently, this can be used to estimate the change in hemispheric and global average reflected solar radiation. The conclusion is that the change of reflected solar flux due to anthropogenic SO 4 = averaged over the Northern Hemisphere is ca. − 1.1 Wm -2 , which is comparable but opposite in sign to the present-day radiative forcing by anthropogenic CO 2 , + 1.5 Wm -2 . Because of the spatial variability of the anthropogenic SO 4 = distribution, its meteorological effects must be studied regionally. That is, global models with regional resolution and regional data are required. Unlike the direct effect on solar irradiance, the relationship of CCN number concentration to mass concentration is not known. Thus it is not yet possible to make quantitatively reliable statements about anthropogenic forcing of cloud albedo, although there is qualitative evidence that the CCN effect may also be substantial. DOI: 10.1034/j.1600-0870.1991. 00013.x
A Study on the Mechanical Properties of Light Weight Concrete by Replacing Course Aggregate with (Pumice) and Cement with (Fly Ash)

Light weight concrete has become more popular in recent years owing to the tremendous advantages it offers over the conventional concrete. Even Light concrete but at the same time strong enough to be used for the structural purpose. Lightweight concrete has been successfully used since the ancient Roman times and it has gained its popularity due to its lower density and superior thermal insulation properties. Compared with Normal weight concrete, Lightweight concrete can significantly reduce the dead load of structural elements, which makes it especially attractive in multi-storey buildings. The most important characteristic of light weight concrete beside its light weight is its low thermal conductivity. This property improves with decreasing density. The adaptation of certain class of light weight concretes gives an outlet for industrial wastes and dismantled wastes which would otherwise create problems for disposal. The conventional mix has been designed for M25 grade concrete. Coarse aggregate replaced with Pumice aggregate in volume percentages of 25% and 33.33% further Cement replaced with the Fly ash in weight percentages of 15%, 20%, 25%, 30% for study in the present investigation. The properties like Compressive strength, Split tensile strength, Flexural strength and Youngs’ modulus of above combinations were studied and compared with conventional design mix concrete. It is observed that there is retardation in Compressive strength, Split tensile strength, Flexural strength and Young’s’ modulus for the light weight aggregate replaced concrete when compared to the concrete made with normal aggregate. For these light weight aggregate concrete mixes when ‘cement’ was replaced by ‘fly ash’ it is noticed that there is a marginal improvement in the properties studied. For 25% replaced light weight aggregate when cement was replaced by 15%, 20%,25% and 30%fly ash, the maximum gain in compressive strength of 18.71% at 28 days is observed for 20% replacement of fly ash. Similarly the gain in split tensile strength, flexural strength and Youngs’ modulus of 16.66%, 29.51% and 10.15% is observed at 20% replacement of fly ash respectively. For 33.33% replaced light weight aggregate when cement was replaced by 15%,20%,25% and 30% fly ash, the maximum gain in compressive strength of 26.3 % is observed for 20% replacement of fly ash. Similarly the gain in split tensile strength, flexural tensile strength and Youngs’ modulus of 19.23%,26% and 3.33% is observed at 20% replacement of fly ash respectively Hence we can infer that 20% replacement of cement by fly ash is optimum proportion among the proportions tested for the properties studied in the present investigation.
Extracción de fibras de agave para elaborar papel y artesanías

Applied research for the sustainable integral use of regional native plants, which was extracted fiber from six species of Agave (common name maguey), three narrow-leaved (A. lechuguilla, A. angustifolia and A. tequilana) and three wide-leaved (A. americana, A. salmiana and A. mapisaga) by using three methods: 1) cooking of pads), 2) fermentation with and without aguamiel (maguey sweet juice) and 3) immersion in water open sky. By considering the variables color, odor, softness, enguiche, easiness of defibration and time spent. In conclusion, most practical treatment was the boiling of the fleshy leaves, but not the most economical and environmentally friendly one. The results got up to this stage indicate that paper can be obtained from each of the six species and that it shows characteristic features which make it attractive to be applied in various craft uses. In particular, the species producing the most paper with the best quality, i.e., for writing and drawing, were A. salmiana and A. mapisaga.
Boosting for Correlated Binary Classification

Boosting is a successful method for dealing with problems of high-dimensional classification of independent data. However, existing variants do not address the correlations in the context of longitudinal or cluster study-designs with measurements collected across two or more time points or in clusters. This article presents two new variants of boosting with a focus on high-dimensional classification problems with matched-pair binary responses or, more generally, any correlated binary responses. The first method is based on the generic functional gradient descent algorithm and the second method is based on a direct likelihood optimization approach. The performance and the computational requirements of the algorithms were evaluated using simulations. Whereas the performance of the two methods is similar, the computational efficiency of the generic-functional-gradient-descent-based algorithm far exceeds that of the direct-likelihood-optimization-based algorithm. The former method is illustrated using data on gene expression changes in de novo and relapsed childhood acute lymphoblastic leukemia. Computer code implementing the algorithms and the relevant dataset are available online as supplemental materials.
Study of the vortex-ring transition in superfluid /sup 4/He

Extensive experimental results on the vortex-ring transition in liquid /sup 4/He between 0.3 and 0.7degreeK are presented. These high-field mobilities and vortex-ring creation rates for positive and negative ions at pressures up to the melting pressure and at various /sup 3/He impurity concentrations. The significance of our observations is discussed in terms of possible models of the transition mechanism. (AIP)
Cosmological evolution of radio sources

Abstract It is commonly accepted that, in the frame of the unified scheme (Urry and Padovani, 1995), compact (CD ‘core-dominated') and extended (LD ‘lobe-dominated') extragalactic radio sources differ only by the orientation of their radio axis towards the observer. On the other hand, in the relativistic beaming models it is assumed that all radio sources have an intrinsically steep spectrum and flat-spectrum sources arise if their strongly Doppler-boosted core dominates the total flux in the observed frequency range. It is also assumed that all extragalactic radio sources with flux density S 1.4 > 1 mJy belong to two parent populations: FRI and FRII differing by their radio power, optical/UV spectral characteristics, very likely by jet power and speed, etc. In this contribution, we select and use the 1.4 GHz normalized differential counts n(S) of radio sources of different morphological types, to verify predictions of the dual-population model of radio source evolution recently proposed by Jackson and Wa.
A Real-Time Convection-Allowing Ensemble Prediction System Initialized by Mesoscale Ensemble Kalman Filter Analyses

AbstractIn May and June 2013, the National Center for Atmospheric Research produced real-time 48-h convection-allowing ensemble forecasts at 3-km horizontal grid spacing using the Weather Research and Forecasting (WRF) Model in support of the Mesoscale Predictability Experiment field program. The ensemble forecasts were initialized twice daily at 0000 and 1200 UTC from analysis members of a continuously cycling, limited-area, mesoscale (15 km) ensemble Kalman filter (EnKF) data assimilation system and evaluated with a focus on precipitation and severe weather guidance. Deterministic WRF Model forecasts initialized from GFS analyses were also examined. Subjectively, the ensemble forecasts often produced areas of intense convection over regions where severe weather was observed. Objective statistics confirmed these subjective impressions and indicated that the ensemble was skillful at predicting precipitation and severe weather events. Forecasts initialized at 1200 UTC were more skillful regarding precipita.
Theory of Metal Surfaces: Induced Surface Charge and Image Potential.

Abstract : The paper contributes to the theory of the electron density distribution induced at a metal surface by a small static external charge distribution. As a first application, profiles of the charge induced by a uniform external electric field are obtained for metals of different bulk electron densities. A quantity of particular interest is the position of the center of mass, xo, of these profiles, for which present numerical values are given. (The x-axis is taken along the surface normal). Next, the case of a small point charge, q, with x-coordinate x1 well outside the surface, is treated. The authors locate x(o), the effective position of the metal surface, relative to the last lattice plane of the crystal. They also discuss the implications of these results for alkali adsorption on metal substrates, the capacitances of small-gap condensers, and field-emission experiments. (Author)
Agrogel usage in cultivation of trees planted in ridges.

The experiment was conducted in the years 2005-2008 in the Research - Development Station in Samotwor, of the Wroclaw University of Environmental and Life Sciences. Apple trees of 'Ligol' and 'Pinova' grafted on M.26 were planted in the spring 2005, in 3.5 x 1 m spacing (2857 trees/ha). The trees were planted in a traditional way, into pits or in ridges. The second factor was the usage of agrogel as a soil additive. Agrogel was applied in the form of a tape made of thick agro-textile with a granulate preparation closed inside, what is called a geo-textile. The tape was soaked in water for 24 hours and then spread on the soil in a line along the future row of trees. The experiment was established according to the method of randomized split-blocks, in four replications, with four trees on each plot. A combination of planting trees in ridges with simultaneous use of agrogel proved to be an advantageous way to improve the yielding of 'Ligol'. The trees of 'Pinova' were characterized as having a smaller yield size, in the first three years after the trees were planted in ridges, regardless of the agrogel application. In the case of 'Ligol' planted in ridges, agrogel brought about an evident tendency to improvement of tree vegetative growth, measured by TCSA in all the years that the experiment was carried out. As far as 'Pinova' was concerned, the poorer tree growth when planted in ridges, proved to be more evident when agrogel was simultaneously used.
Free Oscillations and Surfactant Studies of Superdeformed Drops in Microgravity

An unprecedented microgravity observation of maximal shape oscillations of a surfactant-bearing water drop the size of a ping-pong ball was observed during a mission of Space Shuttle Columbia. The goal of the research, of which this observation is a part, was to study the rheological properties of liquid drop surfaces on which are adsorbed surfactant molecules under conditions not possible at 1g. Numerical computation of the evolution of the shape of greatly deformed drops using the boundary integral method has successfully predicted the observed drop shapes over a complete cycle of oscillation, thereby permitting the calculation of the dynamic surface tension under these unique conditions.
A theoretical analysis of free-surface flows of saturated granular–liquid mixtures

A simple two-phase model for steady fully developed flows of particles and water over erodible inclined beds is developed for situations in which the water and particles have the same depth. The rheology of the particles is based on recent numerical simulations and physical experiments, the rheology of the fluid is based on an eddy viscosity, and the interaction between the particles and the fluid is through drag and buoyancy. Numerical solutions of the resulting differential equations and boundary conditions provide velocity profiles of the fluid and particles, the concentration profile of the particles, and the depth of the flow at a given angle of inclination of the bed. Simple approximations permit analytical expressions for the flow velocities and the depth of flow to be obtained that agree with the numerical solutions and those measured in experiments.
Towards a standardized notation and terminology in multiway analysis

This paper presents a standardized notation and terminology to be used for three‐ and multiway analyses, especially when these involve (variants of) the CANDECOMP/PARAFAC model and the Tucker model. The notation also deals with basic aspects such as symbols for different kinds of products, and terminology for three‐ and higher‐way data. The choices for terminology and symbols to be used have to some extent been based on earlier (informal) conventions. Simplicity and reduction of the possibility of confusion have also played a role in the choices made. Copyright © 2000 John Wiley & Sons, Ltd.
North Atlantic Tropical Cyclones and U.S. Flooding

Riverine flooding associated with North Atlantic tropical cyclones (TCs) is responsible for large societal and economic impacts. The effects of TC flooding are not limited to the coastal regions, but affect large areas away from the coast, and often away from the center of the storm. Despite these important repercussions, inland TC flooding has received relatively little attention in the scientific literature, although there has been growing media attention following Hurricanes Irene (2011) and Sandy (2012). Based on discharge data from 1981 to 2011, the authors provide a climatological view of inland flooding associated with TCs, leveraging the wealth of discharge measurements collected, archived, and disseminated by the U.S. Geological Survey (USGS). Florida and the eastern seaboard of the United States (from South Carolina to Maine and Vermont) are the areas that are the most susceptible to TC flooding, with typical TC flood peaks that are 2 to 6 times larger than the local 10-yr flood peak, causing ma.
Quantum size effects in Pb films from first principles: The role of the substrate

Three different Pb films--free standing, on a semiconducting Ge(111) substrate, and on a metallic Cu(111) substrate--are studied with first-principles calculations. Our studies show that the properties of these films--surface energy, work function, and lattice relaxation--oscillate strongly with the film thickness. The oscillation follows a bilayer pattern interrupted by even-odd crossovers. However, the positions of the crossovers and the separation between the crossovers depend on the substrate, showing that the substrate plays an important role in the Pb film properties. In particular, the results for Pb films on Cu(111) substrate challenge the existing physical picture of Pb films.
Estimation of the adaptive optics long-exposure point-spread function using control loop data

Astronomical images obtained with adaptive optics systems can be enhanced by using image restoration techniques. However, this usually requires an accurate knowledge of the system point-spread function (PSF) which is variable in time. We present a method to estimate the PSF related to each image, using data from the adaptive optics control computer, namely, the wave-front sensor measurements and the commands to the deformable mirror, accumulated in synchronization with the acquisition. This method requires no extra observing time and has been successfully tested on PUEO, the Canada–France–Hawaii Telescope adaptive optics system. With this system, accurate PSF estimations could be achieved for guide stars of magnitude 13 or brighter.
Linear parameter varying control of a doubly fed induction generator based wind turbine with primary grid frequency support

This paper proposes a control method for a doubly fed induction generator (DFIG) driven by a wind turbine, whose rotor is connected to the power grid via two back‐to‐back pulse‐width modulation power converters. First, we design a rotor current controller for this system using the linear matrix inequality based approach to linear parameter varying systems, which takes into account the nonlinear dynamics of the system. We propose a two‐loop hierarchical control structure. The inner‐loop current controller, which considers the synchronous speed and the generator rotor speed as the components of the parameter vector, achieves tracking of the rotor current reference signals. The outer‐loop electrical torque controller aims for wind energy capture maximization and also grid frequency support, and it generates the reference rotor current. We perform a controller reduction for the inner‐loop linear parameter varying controller, which is not doable by conventional model‐reduction techniques, because the controller is parameter dependent. In simulation, the reduced‐order controller has been tested on a nonlinear fourth‐order DFIG model with a two‐mass model for the drive train. Stability and high performance have been achieved over the entire operating range of the DFIG in the wind turbine. Simulation results have demonstrated the capability of the proposed two‐loop control system to implement also grid frequency support. Copyright © 2013 John Wiley & Sons, Ltd.