541 research outputs found

    Capitalizing on Multiple Intelligences to Enhance Vocabulary Development in a Sixth Grade Classroom

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    This study was designed to determine if Multiple Intelligence Theory is a more effective approach to vocabulary development than direct instruction. Eighty Sixth Grade students from a suburban school district in Western New York were the subjects for this study. In order to determine the students\u27 prior knowledge of the 60 words to be used in the study, the students were given a pretest. The study was conducted over six weeks with the students receiving a new vocabulary list consisting of ten words from the pretest each week. During three of the weeks the students were taught via direct instruction. During the remaining three weeks a multiple intelligence approach was employed. The amount of time during the school day devoted to vocabulary instruction was the same regardless of instructional approach. Specific instructional activities and lessons for each approach are outlined in the thesis. At the end of each week a posttest was given to the students. The researcher evaluated the growth made during each week and searched for a statistically significant difference between the means of the two approaches. The results forded that both methods were indeed effective in enhancing vocabulary growth in sixth grade students. However, when comparing the means of the two approaches, there was a statistically significant difference in favor of Multiple Intelligence Theory

    Capitalizing on Multiple Intelligences to Enhance Vocabulary Development in a Sixth Grade Classroom

    Get PDF
    This study was designed to determine if Multiple Intelligence Theory is a more effective approach to vocabulary development than direct instruction. Eighty Sixth Grade students from a suburban school district in Western New York were the subjects for this study. In order to determine the students\u27 prior knowledge of the 60 words to be used in the study, the students were given a pretest. The study was conducted over six weeks with the students receiving a new vocabulary list consisting of ten words from the pretest each week. During three of the weeks the students were taught via direct instruction. During the remaining three weeks a multiple intelligence approach was employed. The amount of time during the school day devoted to vocabulary instruction was the same regardless of instructional approach. Specific instructional activities and lessons for each approach are outlined in the thesis. At the end of each week a post-test was given to the students. The researcher evaluated the growth made during each week and searched for a statistically significant difference between the means of the two approaches. The results forded that both methods were indeed effective in enhancing vocabulary growth in sixth grade students. However, when comparing the means of the two approaches, there was a statistically significant difference in favor of Multiple Intelligence Theory

    Railway multibody simulation with the knife-edge-equivalent wheel–rail constraint equations

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    This paper describes a new numerical procedure for the modelling and simulation of the wheel–rail contact in railway dynamic simulations. The method is called knifeedge- equivalent contact constraint method, or simply KEC-method. Using this method, the wheel–rail contact is modelled as rigid or constraint-based using a set of kinematic constraints that eliminates one-degree of freedom of relative wheel–rail motion. The KECmethod uses a transformed but equivalent wheel profile in contact with a single-point rail. This equivalent profile has the property of producing the same wheelset-rail relative kinematics as the real wheel–rail profiles. The method can be used efficiently online while achieving better computational times than using contact lookup tables. Compared with existing constraint methods, the KEC-method has the following advantages: (1) simplification of the wheel–rail contact constraints, (2) simplified wheel–rail profiles, (3) online solution of the contact constraints, (4) reduction of the number of surface parameters, and (5) increased computational efficiency. A comparative study with respect to the use of efficient contact lookup tables in the simulation of Metro de Sevilla (metropolitan train in the city of Sevilla) shows that this contact method is appropriate to simulate the dynamics of a railway vehicle efficiently.Spanish Ministry of Science, Innovation and Universities under project reference TRA2017-86355-C2-1-R and the Spanish Ministry of Science, Innovation and Universities under the Mobility Program ‘José Castillejo’ with reference CAS18/00072

    Simultaneous time-space resolved reflectivity and interferometric measurements of dielectrics excited with femtosecond laser pulses

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    13 pags., 7 figs., 1 tab.Simultaneous time-and-space resolved reflectivity and interferometric measurements over a temporal span of 300 ps have been performed in fused silica and sapphire samples excited with 800 nm, 120 fs laser pulses at energies slightly and well above the ablation threshold. The experimental results have been simulated in the frame of a multiple-rate equation model including light propagation. The comparison of the temporal evolution of the reflectivity and the interferometric measurements at 400 nm clearly shows that the two techniques interrogate different material volumes during the course of the process. While the former is sensitive to the evolution of the plasma density in a very thin ablating layer at the surface, the second yields an averaged plasma density over a larger volume. It is shown that self-trapped excitons do not appreciably contribute to carrier relaxation in fused silica at fluences above the ablation threshold, most likely due to Coulomb screening effects at large excited carrier densities. For both materials, at fluences well above the ablation threshold, the maximum measured plasma reflectivity shows a saturation behavior consistent with a scattering rate proportional to the plasma density in this fluence regime. Moreover, for both materials and for pulse energies above the ablation threshold and delays in the few tens of picoseconds range, a simultaneous >low reflectivity> and >low transmission> behavior is observed. Although this behavior has been identified in the past as a signature of femtosecond laser-induced ablation, its origin is alternatively discussed in terms of the optical properties of a material undergoing strong isochoric heating, before having time to substantially expand or exchange energy with the surrounding media.This work has been partly funded by Laserlab-Europe (Grant Agreement No. 284464, EU’s Seventh Framework Programme, Project No. SLIC002014), by the Spanish Ministry of Economy and Competiveness (Project No. TEC2014-52642- C2-1-R) as well as by the Danish Council for Independent Research | Natural Sciences. M.G.-L. acknowledges the FPU (Formación de Profesorado Universitario) Grant No. AP2012- 0217 awarded by the Spanish Ministry of Education.Peer Reviewe

    Electron affinity of Li: A state-selective measurement

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    We have investigated the threshold of photodetachment of Li^- leading to the formation of the residual Li atom in the 2p2P2p ^2P state. The excited residual atom was selectively photoionized via an intermediate Rydberg state and the resulting Li^+ ion was detected. A collinear laser-ion beam geometry enabled both high resolution and sensitivity to be attained. We have demonstrated the potential of this state selective photodetachment spectroscopic method by improving the accuracy of Li electron affinity measurements an order of magnitude. From a fit to the Wigner law in the threshold region, we obtained a Li electron affinity of 0.618 049(20) eV.Comment: 5 pages,6 figures,22 reference

    A micro-accelerometer MDO benchmark problem

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    Many optimization and coordination methods for multidisciplinary design optimization (MDO) have been proposed in the last three decades. Suitable MDO benchmark problems for testing and comparing these methods are few however. This article presents a new MDO benchmark problem based on the design optimization of an ADXL150 type lateral capacitive micro-accelerometer. The behavioral models describe structural and dynamic effects, as well as electrostatic and amplification circuit contributions. Models for important performance indicators such as sensitivity, range, noise, and footprint area are presented. Geometric and functional constraints are included in these models to enforce proper functioning of the device. The developed models are analytical, and therefore highly suitable for benchmark and educational purposes. Four different problem decompositions are suggested for four design cases, each of which can be used for testing MDO coordination algorithms. As a reference, results for an all-in-one implementation, and a number of augmented Lagrangian coordination algorithms are given. © 2009 The Author(s)

    One-dimensional Model of a Gamma Klystron

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    A new scheme for amplification of coherent gamma rays is proposed. The key elements are crystalline undulators - single crystals with periodically bent crystallographic planes exposed to a high energy beam of charged particles undergoing channeling inside the crystals. The scheme consists of two such crystals separated by a vacuum gap. The beam passes the crystals successively. The particles perform undulator motion inside the crystals following the periodic shape of the crystallographic planes. Gamma rays passing the crystals parallel to the beam get amplified due to interaction with the particles inside the crystals. The term `gamma klystron' is proposed for the scheme because its operational principles are similar to those of the optical klystron. A more simple one-crystal scheme is considered as well for the sake of comparison. It is shown that the gamma ray amplification in the klystron scheme can be reached at considerably lower particle densities than in the one-crystal scheme, provided that the gap between the crystals is sufficiently large.Comment: RevTeX4, 22 pages, 4 figure

    A new approach for the limit to tree height using a liquid nanolayer model

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    Liquids in contact with solids are submitted to intermolecular forces inferring density gradients at the walls. The van der Waals forces make liquid heterogeneous, the stress tensor is not any more spherical as in homogeneous bulks and it is possible to obtain stable thin liquid films wetting vertical walls up to altitudes that incompressible fluid models are not forecasting. Application to micro tubes of xylem enables to understand why the ascent of sap is possible for very high trees like sequoias or giant eucalyptus.Comment: In the conclusion is a complementary comment to the Continuum Mechanics and Thermodynamics paper. 21 pages, 4 figures. Continuum Mechanics and Thermodynamics 20, 5 (2008) to appea
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