226 research outputs found

    DETERMINATION OF PRE-SERVICE CLASSROOM TEACHERS’ COGNITIVE STRUCTURES OF COMMUNICATION, COOPERATION AND DECISION-MAKING SKILLS VIA A WORD ASSOCIATION TEST

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    The purpose of the current study is to determine pre-service classroom teachers’ cognitive structure regarding communication, cooperation and decision-making skills, which are among the basic life skills addressed in the Life Sciences curriculum. The current study employed qualitative research methods. The study group of the current research is comprised of 111 pre-service classroom teachers attending the Department of Classroom Teacher Training in a state university located in the Marmara region and having taken the course “Life Sciences Teaching”. A word association test prepared to test the skills addressed in the current study was used as the data collection tool. This word association test focused on three of the basic life skills; communication, cooperation and decision-making skills. By examining the words written by the pre-service teachers related to the these three skills in a detailed manner, a frequency table showing how many times the concepts were repeated was prepared and on the basis of the cut-off points, concept maps were developed. As a result of the analysis, it was found that the pre-service classroom teachers produced a total of 154 concepts in relation to the three skills. When the concepts most frequently produced by the pre-service teachers were examined, it was found that “human” is the concept most frequently produced for the communication skill, “group” is the concept most frequently produced for the cooperation skill and “reaching a conclusion” is the concept most frequently produced for the decision-making skill

    Emergency crowd simulation for outdoor environments

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    Cataloged from PDF version of article.We simulate virtual crowds in emergency situations caused by an incident, such as a fire, an explosion, or a terrorist attack. We use a continuum dynamics-based approach to simulate the escaping crowd, which produces more efficient simulations than the agent-based approaches. Only the close proximity of the incident region, which includes the crowd affected by the incident, is simulated. We use a model-based rendering approach where a polygonal mesh is rendered for each agent according to the agent's skeletal motion. To speed up the animation and visualization, we employ an offline occlusion culling technique. We animate and render a pedestrian model only if it is visible according to the static visibility information computed. In the pre-processing stage, the navigable area is decomposed into a grid of cells and the from-region visibility of these cells is computed with the help of hardware occlusion queries. (C) 2009 Elsevier Ltd. All rights reserved

    Use of a Viscous Flow Simulation Code for Static Aeroelastic Analysis of a Wing at High-Lift Conditions

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    In this paper, we present a static aeroelastic analysis of a wind tunnel test model of a wing in high-lift configuration using a viscous flow simulation code. The model wing was tailored to deform during the tests by amounts similar to a composite airliner wing in highlift conditions. This required use of a viscous flow analysis to predict the lift coefficient of the deformed wing accurately. We thus utilized an existing static aeroelastic analysis framework that involves an inviscid flow code (Cart3d) to predict the deformed shape of the wing, then utilized a viscous flow code (Overflow) to compute the aerodynamic loads on the deformed wing. This way, we reduced the cost of flow simulations needed for this analysis while still being able to predict the aerodynamic forces with reasonable accuracy. Our results suggest that the lift of the deformed wing may be higher or lower than that of the non-deformed wing, and the washout deformation of the wing is the key factor that changes the lift of the deformed wing in two distinct ways: while it decreases the lift at low to moderate angles of attack simply by lowering local angles of attack along the span, it increases the lift at high angles of attack by alleviating separation

    Evaluation of in vitro antiprotozoal activity of Ajuga laxmannii and its secondary metabolites

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    Abstract: Context: Some Ajuga L. (Lamiaceae) species are traditionally used for the treatment of malaria, as well as fever, which is a common symptom of many parasitic diseases. Objective: In the continuation of our studies on the identification of antiprotozoal secondary metabolites of Turkish Lamiaceae species, we have investigated the aerial parts of Ajuga laxmannii. Materials and methods: The aerial parts of A. laxmannii were extracted with MeOH. The H2O subextract was subjected to polyamide, C18-MPLC and SiO2 CCs to yield eight metabolites. The structures of the isolates were elucidated by NMR spectroscopy and MS analyses. The extract, subextracts as well as the isolates were tested for their in vitro antiprotozoal activities against Plasmodium falciparum, Trypanasoma brucei rhodesiense, T. cruzi and Leishmania donovani at concentrations of 90–0.123 μg/mL. Results: Two iridoid glycosides harpagide (1) and 8-O-acetylharpagide (2), three o-coumaric acid derivatives cis-melilotoside (3), trans-melilotoside (4) and dihydromelilotoside (5), two phenylethanoid glycosides verbascoside (6) and galactosylmartynoside (7) and a flavone-C-glycoside, isoorientin (8) were isolated. Many compounds showed moderate to good antiparasitic activity, with isoorientin (8) displaying the most significant antimalarial potential (an IC50 value of 9.7 μg/mL). Discussion and conclusion: This is the first report on the antiprotozoal evaluation of A. laxmannii extracts and isolates. Furthermore, isoorientin and dihydromelilotoside are being reported for the first time from the genus Ajuga

    Computational Design of a Krueger Flap Targeting Conventional Slat Aerodynamics

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    In this study, we demonstrate the design of a Krueger flap as a substitute for a conventional slat in a high-lift system. This notional design, with the objective of matching equivalent-mission performance on aircraft approach, was required for a comparative aeroacoustic study with computational and experimental components. We generated a family of high-lift systems with Krueger flaps based on a set of design parameters. Then, we evaluated the high-lift systems using steady 2D RANS simulations to find a good match for the conventional slat, based on total lift coefficients in free-air. Finally, we evaluated the mean aerodynamics of the high-lift systems with Krueger flap and conventional slat as they were installed in an open-jet wind tunnel flow. The surface pressures predicted with the simulations agreed well with experimental results

    Mass Taxon-Sampling as a Strategy towards Illuminating the Natural History of Campanula (Campanuloideae)

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    Speciose clades usually harbor species with a broad spectrum of adaptive strategies and complex distribution patterns, and thus constitute ideal systems to disentangle biotic and abiotic causes underlying species diversification. The delimitation of such study systems to test evolutionary hypotheses is difficult because they often rely on artificial genus concepts as starting points. One of the most prominent examples is the bellflower genus Campanula with some 420 species, but up to 600 species when including all lineages to which Campanula is paraphyletic. We generated a large alignment of petD group II intron sequences to include more than 70% of described species as a reference. By comparison with partial data sets we could then assess the impact of selective taxon sampling strategies on phylogenetic reconstruction and subsequent evolutionary conclusions
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