22 research outputs found

    Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

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    ABSTRACT: In this work, low density polyethylene (LDPE)/plasticized starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young’s modulus and tensile strength) improved ostensibly. The Young’ modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior

    Autotoxicity Effects of Water Extracts of Canola on Germination and Seedling Growth of Two Canola Varieties

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    Abstract \ud Autotoxicity is injurious effects of a plant on itself via production and released diverse allelochemicals. In order to determine autotoxicity effects of water extract of canola residues on germination traits of two varieties: Elait and Golzard was investigated. Two factorial experiments based a completely randomized design with 3 replications were conducted separately. Treatments were 3 kinds of canola water extract (shoot, root and shoot plus root) and 5 concentrations (0, 25, 50, 75 and 100 percentage) of extracts. Each plot was a Petri-dish with 9 cm diameter and 3 cm depth. At the end of germination, germination inhibition percentage, root and shoot length, root and shoot dry weight and seedling dry weight were determined according to ISTA standards. The results showed water extract of canola had difference autotoxicity effects on germination traits of canola varieties. Increasing concentration of extracts resulted to increased germination inhibition percentage (29.6 and 33.9) and decreased root length (63.3 and 73.8), shoot length (52.2 and 76.6), root dry weight (32.6 and 64.9), shoot dry weight (59.1 and 43.6) and the seedling dry weight (42.1 and 55.5), respectively. Germination traits of variety Golzard was more sensitive at canola extract. The water extract of root than shoot and shoot plus root had the most autotoxicity effects on germination and seedling growth of canola varieties.\ud \ud Keywords: Autotoxicity, Canola, Germination propertie

    Integrated halide perovskite photoelectrochemical cells with solar driven water splitting efficiency of 20.8

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    Achieving high solar to hydrogen STH efficiency concomitant with long term durability using low cost, scalable photo absorbers is a long standing challenge. Here we report the design and fabrication of a conductive adhesive barrier CAB that translates gt;99 of photoelectric power to chemical reactions. The CAB enables halide perovskite based photoelectrochemical cells with two different architectures that exhibit record STH efficiencies. The first, a co planar photocathode photoanode architecture, achieved an STH efficiency of 13.4 and 16.3 amp; 8201;h to t60, solely limited by the hygroscopic hole transport layer in the n i p device. The second was formed using a monolithic stacked silicon perovskite tandem, with a peak STH efficiency of 20.8 and 102 amp; 8201;h of continuous operation before t60 under AM 1.5G illumination. These advances will lead to efficient, durable, and low cost solar driven water splitting technology with multifunctional barrier

    Sharing aquatic genetic resources across jurisdictions: playing ‘chicken’ in the sea

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    International regimes regulating access and benefit sharing were originally designed to promote conservation and fairness objectives concerning the use of the world’s biological resources for their genetic material value. These regimes determine from whom permission is required to take the resources and who obtains the benefits of their use. They have evolved separate frameworks in three distinct jurisdictional areas—within national jurisdiction, beyond national jurisdiction and in the Antarctic Treaty Area. This article argues that if these regimes continue to evolve separately, there is a strong temptation for countries to play ‘chicken’ with biological resource governance through forum shopping or opting out of agreements that do not suit their political ends. Using game theory and a transgenic tilapia fish example incorporating genetic material from the three jurisdictional areas, it illustrates the legal and ethical dilemmas that can arise from the territorial (jurisdictional) approach to access and benefit sharing—to the detriment of fairness and conservation in tilapia’s countries of origin. Tilapias are known as the ‘chicken of the sea’ because they dominate global farmed production and developing countries depend on them as their primary source of protein, livelihoods and trade. This means there will be serious consequences if the regimes do not achieve their fairness and conservation objectives for sharing their genetic material. This article concludes that a purpose-driven cooperative governance approach can sidestep the game of chicken and promote fairer and more conservation focused outcomes than the current jurisdictional approach for the developing country providers of migratory aquatic resources
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