5,854 research outputs found
The Analysis of Two Esl/efl Websites: Englishclub and Activities for Esl Students
This study reviewed two well known ESL/EFL websites namely EnglishClub and Activities for ESL Students using the website evaluation framework proposed by Hasan and Abuelrub (2011). The writers found that Activities for ESL Students met 79.92% of the website evaluation criteria with 211 of the total score; while EnglishClub met 79.54% of the website evaluation criteria with 210 of the total score. Thus there was no significant difference between these two websites. Both EnglishClub and Activities for ESL Students are good for ESL/EFL learner
An approach for configuring space photovoltaic tandem arrays based on cell layer performance
Meeting solar array performance goals of 300 W/Kg requires use of solar cells with orbital efficiencies greater than 20 percent. Only multijunction cells and cell layers operating in tandem produce this required efficiency. An approach for defining solar array design concepts that use tandem cell layers involve the following: transforming cell layer performance at standard test conditions to on-orbit performance; optimizing circuit configuration with tandem cell layers; evaluating circuit sensitivity to cell current mismatch; developing array electrical design around selected circuit; and predicting array orbital performance including seasonal variations
P-wave and surface wave survey for permafrost analysis in alpine regions
We discuss the results of seismic survey to delineate temporal and spatial changes of frozen layer in Alpine environments. The seismic characterization allows us to detect changes of soil deformability properties related to the temperature effect on subsoi
On Systems of Active Particles Perturbed by Symmetric Bounded Noises: A Multiscale Kinetic Approach
We consider an ensemble of active particles, i.e., of agents endowed by internal variables u(t). Namely, we assume that the nonlinear dynamics of u is perturbed by realistic bounded symmetric stochastic perturbations acting nonlinearly or linearly. In the absence of birth, death and interactions of the agents (BDIA) the system evolution is ruled by a multidimensional Hypo-Elliptical Fokker–Plank Equation (HEFPE). In presence of nonlocal BDIA, the resulting family of models is thus a Partial Integro-differential Equation with hypo-elliptical terms. In the numerical simulations we focus on a simple case where the unperturbed dynamics of the agents is of logistic type and the bounded perturbations are of the Doering–Cai–Lin noise or the Arctan bounded noise. We then find the evolution and the steady state of the HEFPE. The steady state density is, in some cases, multimodal due to noise-induced transitions. Then we assume the steady state density as the initial condition for the full system evolution. Namely we modeled the vital dynamics of the agents as logistic nonlocal, as it depends on the whole size of the population. Our simulations suggest that both the steady states density and the total population size strongly depends on the type of bounded noise. Phenomena as transitions to bimodality and to asymmetry also occur
Role of structure of the Pp/magnetite nanocomposites on their thermal properties
The thermal degradation behaviour of polypropylene and its magnetite composites have been investigated by
differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Distribution of magnetite
nanoparticles in a polymer matrix has been studied by scanning and transmission electron microscopy and also
atomic force microscopy. The thermal and mechanical properties of nanocomposites based on polypropylene
and magnetite nanoparticles have also been investigated. It has shown that, the introduction of Fe3O4
nanoparticles in polypropylene increases its thermal stability of about 1000C. The maximum increase in the
thermal stability of PP was observed in the case of a 20% weight content of Fe3O4 nanoparticles in
polypropylene
Evaluating collapse fragility curves for existing buildings retrofitted using seismic isolation
Few studies have investigated so far the collapse capacity of buildings with base-isolation. In such studies, preliminary considerations have been drawn based on a number of assumptions regarding: (i) the methodology used for assessing the collapse capacity, (ii) the collapse conditions and failure modes assumed for both superstructure and isolation system, and (iii) the numerical modeling assumptions. The main results pointed out that the collapse conditions of base-isolated buildings may occur for intensity levels slightly higher than those associated with the design earthquake. In this paper, further developments are made through the use of enhanced models for the description of the behavior of a rubber-based isolation system and the assumption of more rational collapse conditions. Collapse fragility functions, in terms of mean and dispersion values, are proposed for two archetypes representative of existing buildings retrofitted using the seismic isolation technique. The collapse margin ratio (median collapse capacity Sa, C, namely the spectral acceleration associated to a probability of exceedance equal to 50%, divided by the design spectral acceleration at the collapse prevention limit state) has been evaluated for each examined case-study. Values ranging from 1.10 to 1.45 were found
Human Pluripotent Stem Cells and Drug Discovery: A New Beginning
Human pluripotent stem cells (hPSCs) offer unique opportunities to discover and develop a new generation of drugs. Their ability to differentiate into virtually any cell type renders them a cost-effective, renewable source of tissue-specific cell types capable of predicting human responses towards novel chemical entities. Using these improved in vitro models based on physiologically relevant human cell types could result in identifying highly precise and safe compounds, thereby reducing drug attrition rates. Moreover, ability to develop humanised disease models for patient-stratified drug screening makes hPSCs an impeccable tool in translational medicine. In this mini-review we focus on the positives and negatives of utilising hPSC-derived cell types as drug discovery platforms with special emphasis on cardio-, hepato- and embryotoxicity
Lamb and mutton on the farm
"July, 1939""Although lamb and mutton have not been widely used in Missouri farm homes in the past, these meats are now taking on a new significance because of the widespread shift to pasture farming and the increased use of sheep as factors in soil conservation. Lambs and yearlings raised on the farm provide a needed variety of hightly nutritive fresh meat."--First paragraphT.A. Ewing and Flora L. Car
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