417 research outputs found

    Teachers’ Experience of Blended English Language Learning

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    Abstracts: To address current Emiratization goals for teachers who teach English Medium Subjects, the Abu Dhabi Education Council partnered with a for-profit English language professional development provider to conduct a 6-week trial of a blended English language learning program for Emirati teachers. The current qualitative narrative study was undertaken to learn more about the lived experiences of 11 participants in the program. Participants had access to an online training program and spent 60 to 70% of the training program time in self-paced online learning, and attended face to face sessions with an English trainer for 30-40% percent of the training program time. Overall, most participants generally expressed satisfaction with the program, although some participants expressed concerns about the timing for the training, duration, rigor level, and lack of contextualization. The current research base on the efficacy of such programs in the MENA context is limited. Recommendations include further quantitative program evaluation, using learning outcomes data, and incorporating feedback from participants in the current program into planning for future blended language programs. Keynote: education, language learning, blended learning, professional development, United Arab Emirates, Abu Dhab

    Using Unsolvable Anagrams to Induce Escape: Will it Increase Gambling Behavior?

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    Previous research has found an association between gambling as a means of escape and pathological gambling. Likewise, previous laboratory research has found an association between gambling as a means of escape and participants’ gambling behavior. The present experiment had 41 participants play video poker in two sessions. Prior to one session, participants were asked to solve a series of solvable word puzzles. Prior to the other, they were asked to solve a series of unsolvable word puzzles. Consistent with previous research, results demonstrated that participants’ video-poker play was associated with their overall tendency to endorse gambling as a function of escape. However, their behavior did not vary as a function of whether the word puzzles were or were not solvable. These results may suggest that the different word puzzles used in the present procedure were similarly aversive. However, they may also suggest that gambling as an escape represents a general behavior pattern that is not necessarily sensitive to brief environmental manipulations

    Fully Biodegradable Biocomposites with High Chicken Feather Content

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    The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF). In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA), polybutyrate adipate terephthalate (PBAT) and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a torque rheometer having a CF content of 50 and 60 wt %. Due to the low tensile strength of CFs, the resulting materials were penalized in terms of mechanical properties. However, high-loading CF biocomposites resulted in lightweight and thermal-insulating materials when compared with neat bioplastics. Additionally, the adhesion between CFs and the PLA matrix was also investigated and a significant improvement of the wettability of the feathers was obtained with the alkali treatment of the CFs and the addition of a plasticizer like polyethylene glycol (PEG). Considering all the properties, these 100% fully biodegradable biocomposites could be adequate for panel components, flooring or building materials as an alternative to wood–plastic composites, contributing to the valorisation of chicken feather waste as a renewable material.This work was supported by KaRMA2020 project. This project has received funding from the European Union’s Horizon 2020 Research and Innovation program under Grant Agreement n° 723268

    Flexible Biocomposites with Enhanced Interfacial Compatibility Based on Keratin Fibers and Sulfur-Containing Poly(urea-urethane)s

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    Feathers are made of keratin, a fibrous protein with high content of disulfide-crosslinks and hydrogen-bonds. Feathers have been mainly used as reinforcing fiber in the preparation of biocomposites with a wide variety of polymers, also poly(urea-urethane)s. Surface compatibility between the keratin fiber and the matrix is crucial for having homogenous, high quality composites with superior mechanical properties. Poly(urea-urethane) type polymers are convenient for this purpose due to the presence of polar functionalities capable of forming hydrogen-bonds with keratin. Here, we demonstrate that the interfacial compatibility can be further enhanced by incorporating sulfur moieties in the polymer backbone that lead to new fiber-matrix interactions. We comparatively studied two analogous thermoplastic poly(urea-urethane) elastomers prepared starting from the same isocyanate-functionalized polyurethane prepolymer and two aromatic diamine chain extenders, bis(4-aminophenyl) disulfide (TPUU-SS) and the sulfur-free counterpart bis(4-aminophenyl) methane (TPUU). Then, biocomposites with high feather loadings (40, 50, 60 and 75 wt %) were prepared in a torque rheometer and hot-compressed into flexible sheets. Mechanical characterization showed that TPUU-SS based materials underwent higher improvement in mechanical properties than biocomposites made of the reference TPUU (up to 7.5-fold higher tensile strength compared to neat polymer versus 2.3-fold). Field Emission Scanning Electron Microscope (FESEM) images also provided evidence that fibers were completely embedded in the TPUU-SS matrix. Additionally, density, thermal stability, and water absorption of the biocomposites were thoroughly characterized.This work was supported by KaRMA2020 project. This project has received funding from the European Union’s Horizon 2020 Research and Innovation program under Grant Agreement n 723268

    Homogenization of Mutually Immiscible Polymers Using Nanoscale Effects: A Theoretical Study

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    4 p.A theoretical study to investigate homogenization of mutually immiscible polymers using nanoscale effects has been performed. Specifically, the miscibility behavior of all-polymer nanocomposites composed of linear-polystyrene (PS) chains and individual cross-linked poly(methyl methacrylate)-nanoparticles (PMMA-NPs) has been predicted. By using a mean field theory accounting for combinatorial interaction energy and nanoparticle-driven effects, phase diagrams were constructed as a function of PMMA-NP size, PS molecular weight, and temperature. Interestingly, complete miscibility (i.e., homogeneity) was predicted from room temperature to 675 K for PMMA-nanoparticles with radius less than ~7 nm blended with PS chains (molecular weight 150 kDa, nanoparticle volume fraction 20%) in spite of the well-known immiscibility between PS and PMMA. Several nanoscale effects affecting miscibility in PMMA-NP/PS nanocomposites involving small PMMA-nanoparticles are discussed.Financial support by MEC (Grant no. CSD2006-53), Basque Government (Grupos Consolidados IT-274-07), and Diputación de Gipuzkoa through C. I. C. Nanogune—Consolider and Nanotron Project is gratefully acknowledged

    Capital account regulations and the trading system: a compatibility review

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    This repository item contains a single issue of the Pardee Center Task Force Reports, a publication series that began publishing in 2009 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. Spanish version produced by the Center for the Study of State and Society, Buenos Aires. Portuguese version coordinated by Daniela Magalhaes Prates, a contributing author of the report, in collaboration with Ana Trivellato (translator), and Maria Inês Amorozo (graphic designer).This report is the product of the Pardee Center Task Force on Regulating Capital Flows for Long-Run Development and builds on the Task Force´s first report published in March 2012. The Pardee Center Task Force was convened initially in September 2011 as consensus was emerging that the global financial crisis has re-confirmed the need to regulate cross-border finance. The March 2012 report argues that international financial institutions – and in particular the International Monetary Fund – need to support measures that would allow capital account regulations (CARs) to become a standard and effective part of the macroeconomic policy toolkit. Yet some policymakers and academics expressed concern that many nations — and especially developing countries — may not have the flexibility to adequately deploy such regulations because of trade and investment treaties they are party to. In June 2012, the Pardee Center, with the Center for the Study of State and Society (CEDES) in Argentina and Global Development and Environment Institute (GDAE) at Tufts University, convened a second Task Force workshop in Buenos Aires specifically to review agreements at the WTO and various Free Trade Agreements (FTAs) and Bilateral Investment Treaties (BITs) for the extent to which the trading regime is compatible with the ability to deploy effective capital account regulations. This report presents the findings of that review, and highlights a number of potential incompatibilities found between the trade and investment treaties and the ability to deploy CARs. It also highlights an alarming lack of policy space to use CARs under a variety of FTAs and BITs—especially those involving the United States. Like the first report, it was written by an international group of experts whose goal is to help inform discussions and decisions by policymakers at the IMF and elsewhere that will have implications for the economic health and development trajectories for countries around the world

    Build-To-Specification Vanillin and Phloroglucinol Derived Biobased Epoxy-Amine Vitrimers

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    Epoxy resins are widely used in the composite industry due to their dimensional stability, chemical resistance, and thermo-mechanical properties. However, these thermoset resins have important drawbacks. (i) The vast majority of epoxy matrices are based on non-renewable fossil-derived materials, and (ii) the highly cross-linked molecular architecture hinders their reprocessing, repairing, and recycling. In this paper, those two aspects are addressed by combining novel biobased epoxy monomers derived from renewable resources and dynamic crosslinks. Vanillin (lignin) and phloroglucinol (sugar bioconversion) precursors have been used to develop bi- and tri-functional epoxy monomers, diglycidyl ether of vanillyl alcohol (DGEVA) and phloroglucinol triepoxy (PHTE) respectively. Additionally, reversible covalent bonds have been incorporated in the network by using an aromatic disulfide-based diamine hardener. Four epoxy matrices with di erent ratios of epoxy monomers (DGEVA/PHTE wt%: 100/0, 60/40, 40/60, and 0/100) were developed and fully characterized in terms of thermal and mechanical properties. We demonstrate that their performances are comparable to those of commonly used fossil fuel-based epoxy thermosets with additional advanced reprocessing functionalities.This project has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation program under grant agreement No 74431

    INCORPORATION OF NANOCLAY AND ORANGE PEELS EXTRACT INTO PLA FOR FOOD APPLICATIONS: MIGRATION ASSESSMENT

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    This research investigated the overall and specific migration from two different formulations of PLA: one obtained with addition of nanoclay as a filler (PLA_Clay), and another one obtained with the addition of an antioxidant extract from waste orange peels (OPE) as an active component for food application (PLA_OPE). Overall migration was always below the current European limit of 10 mg/dm2 set for food contact materials (maximum 0.2 mg/dm2 from PLA_Clay into distilled water and 2.7 mg/dm2 from PLA_OPE into 3 % acetic acid). Specific migration of clay elements and particles from PLA_Clay was evaluated by different techniques (atomic absorption spectroscopy, SEM and SEM microanalysis). A very limited release of clay elements was measured, with the highest migration found for calcium. SEM observation showed the release of particles also of size \u3c 1 µm. The migration testing conditions of 10 days at 40 °C showed a swelling of the PLA which was enhanced by nanoclay presence. A maximum 2.5 % of the phenolic compounds of the incorporated OPE were released in the simulant 20 % ethanol, which is compatible with the fact that the OPE had been obtained through aqueous ethanol extraction

    Functionalization of Cellulose Nanocrystals in Choline Lactate Ionic Liquid

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    Cellulose nanocrystals (CNCs) are valuable nanomaterials obtained from renewable resources. Their properties make them suitable for a wide range of applications, including polymer reinforcement. However, due to their highly hydrophilic character, it is necessary to modify their surface with non-polar functional groups before their incorporation into a hydrophobic polymer matrix. In this work, cellulose nanocrystals were modified using a silane coupling agent and choline lactate, an ionic liquid derived from renewable resources, as a reaction medium. Modified cellulose nanocrystals were characterized by infrared spectroscopy, showing new peaks associated to the modification performed. X-ray diffraction was used to analyze the crystalline structure of functionalized cellulose nanocrystals and to optimize the amount of silane for functionalization. Poly(lactic acid) (PLA) nanocomposites containing 1 wt % of functionalized cellulose nanocrystals were prepared. They were characterized by field-emission scanning electron microscopy (FE-SEM) and mechanical tests. The use of choline lactate as reaction media has been shown to be an alternative method for the dispersion and silanization of the cellulose nanocrystals without the addition of an external catalyst.Financial support from the European Commission (FP7 Program, ECLIPSE project FP7-NMP-280786) is gratefully acknowledged

    Brazilian Paralympic sport initiation: The road from Rio to Los Angeles

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    The Paralympic Games are the largest high-performance sport competition for athletes with disabilities (motor, visual and intellectual). Brazil is evolving in the medal table with each edition of the Games, and the country's growth and sporting improvement since the Sydney 2000 Paralympic Games. After Rio 2016 Paralympic Games grow up the necessity of renewal of Brazilian Paralympic talent. This study aims to bring reflections on the actions developed in Brazil that can contribute and improve the formation of new generations of Brazilian Paralympic athletes. This study are bibliographic search was conducted in national and international databases such as: SCIELO, Science Direct, Google Scholar, as well as in the Thesis Bank of the Coordination of Improvement of Higher Education Personnel (CAPES) and also in institutional documents and institutional websites. Paralympic School Games is the most recognized initiative of paralympic sports initiation and have already been the showcase of some of the most talented brazilian athletes and can be considered the main way to reveal new athletes with disabilities in Brazil. Also, University Paralympic Games, School Camping and Paralympic Training Center increase this process in Brazil. Thus, the Paralympic Games of 2024 and 2028, bring good perspectives for the brazilian paralympic sport, besides the possibility of proving the capacity of renewal of paralympic talents, can consolidate the continuity of the country as power in the world paralympic scenario
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