66 research outputs found

    Profiling the educational value of computer games

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    There are currently a number of suggestions for educators to include computer games in formal teaching and learning contexts. Educational value is based on claims that games promote the development of complex learning. Very little research, however, has explored what features should be present in a computer game to make it valuable or conducive to learning. We present a list of required features for an educational game to be of value, informed by two studies, which integrated theories of Learning Environments and Learning Styles. A user survey showed that some requirements were typical of games in a particular genre, while other features were present across all genres. The paper concludes with a proposed framework of games and features within and across genres to assist in the design and selection of games for a given educational scenari

    SSAGES : Software Suite for Advanced General Ensemble Simulations

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    Molecular simulation has emerged as an essential tool for modern-day research, but obtaining proper results and making reliable conclusions from simulations requires adequate sampling of the system under consideration. To this end, a variety of methods exist in the literature that can enhance sampling considerably, and increasingly sophisticated, effective algorithms continue to be developed at a rapid pace. Implementation of these techniques, however, can be challenging for experts and non-experts alike. There is a clear need for software that provides rapid, reliable, and easy access to a wide range of advanced sampling methods and that facilitates implementation of new techniques as they emerge. Here we present SSAGES, a publicly available Software Suite for Advanced General Ensemble Simulations designed to interface with multiple widely used molecular dynamics simulations packages. SSAGES allows facile application of a variety of enhanced sampling techniques—including adaptive biasing force, string methods, and forward flux sampling—that extract meaningful free energy and transition path data from all-atom and coarse-grained simulations. A noteworthy feature of SSAGES is a user-friendly framework that facilitates further development and implementation of new methods and collective variables. In this work, the use of SSAGES is illustrated in the context of simple representative applications involving distinct methods and different collective variables that are available in the current release of the suite. The code may be found at: https://github.com/MICCoM/SSAGES-public

    Developing Biotemplated Data Storage: Room Temperature Biomineralization of L1<inf>0</inf> CoPt Magnetic Nanoparticles

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    L10 cobalt platinum can be used to record data at approximately sixfold higher densities than it is possible to on existing hard disks. Currently, fabricating L10 CoPt requires high temperatures (≈500 °C) and expensive equipment. One ecological alternative is to exploit biomolecules that template nanomaterials at ambient temperatures. Here, it is demonstrated that a dual affinity peptide (DAP) can be used to biotemplate L10 CoPt onto a surface at room temperature from an aqueous solution. One part of the peptide nucleates and controls the growth of CoPt nanoparticles from solution, and the other part binds to SiO2. A native silicon oxide surface is functionalized with a high loading of the DAP using microcontact printing. The DAP biotemplates a monolayer of uniformly sized and shaped nanoparticles when immobilized on the silicon surface. X-ray diffraction shows that the biotemplated nanoparticles have the L10 CoPt crystal structure, and magnetic measurements reveal stable, multiparticle zones of interaction, similar to those seen in perpendicular recording media. This is the first time that the L10 phase of CoPt has been formed without high temperature/vacuum treatment (e.g., annealing or sputtering) and offers a significant advancement toward developing environmentally friendly, biotemplated materials for use in data storage

    The Effect of Leather Fiber upon Vulcanization Characteristics and Physical-Mechanical Properties of Elastomeric Compounds

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    In this work, leather fibers were employed as a component of elastomeric compounds based on NBR, CR and EPDM and studied were made on their effects upon curing characteristics and mechanical properties of the prepared compounds. Evaluation of curing characteristics of the compounds demonstrated that leather fibers have no considerable effect on initial viscosity and curing time of the compounds. The study of mechanical properties of the vulcanized compounds showed that inclusion of leather fibers leads to increasing of tensile strength in NBR based compound due to compatibility between NBR and leather fibers. It is also found that increase in tensile strength in NBR compounds depends on the curing system of the compounds. The results of this work showed considerable increase in hardness for all of the prepared compounds. Abrasion resistance and resilience of the compounds were also measured and reported

    Molecular Mechanism of Specific Recognition of Cubic Pt Nanocrystals by Peptides and of the Concentration-Dependent Formation from Seed Crystals

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    Metal nanocrystals enable new functionality in sensors, biomarkers, and catalysts while mechanisms of shape-control in synthesis remain incompletely understood. This study explains mechanisms of biomolecule recognition and ligand-directed growth of cubic platinum nanocrystals in atomic detail using molecular dynamics simulation (MD), synthesis, and characterization. Peptide T7 is shown to selectively recognize {100} bounded nanocubes through preferential adsorption near the edges as opposed to facet centers. Spatial preferences in peptide binding are related to differences in the binding of water molecules and conformational matching of polarizable atoms in the peptide to {100} epitaxial sites. Changes in peptide concentration also have profound impact on attraction versus repulsion on a given surface. As an example, the selective synthesis of cubes in the presence of peptide T7 demonstrates that only intermediate T7 concentration leads to high yield. High-resolution transmission electron microscopy (HRTEM) shows concentration-dependent changes in crystal shape, yield, and size. Large-scale MD simulations explain associated differences in facet coverage and in adsorption energies of T7 peptides on cuboctahedral seed crystals, supporting a growth mechanism of adatom deposition. A similar analysis using a different peptide S7 is presented as well. Emerging computational opportunities to predict ligand binding to metal nanocrystals and rationalize growth preferences are summarized
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