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Navarro, H., Marco, L. M., Araneda, A. A., & Bennun, L. (2019). Spatial distribution of Si in Pinus Insigne (Pinus radiata) Wood using micro XRF by Synchrotron Radiation. J. Wood Chem. Technol., 39(3), 187–198.
Abstract: Silicon, while not an essential element, is known to have positive roles in certain vegetable species. For instance, it has been recognized to protect them from biotic and abiotic stress. Due to the fact that certain species accumulate the aforementioned element in their tissues, the determination of its concentration is of importance in different disciplines, such as dendrology, plant physiology, forest management, agroecology, and also in the wood industry. Usually, its quantification is preceded by a series of digestion steps that, aside from been time-consuming, and contamination-prone, prevents from conducting a spatial distribution of the element on the sample. In this research, samples of Pinus radiata wood were studied using a synchrotron radiation source that allowed direct scanning of its surface without any treatment, and the determination of silicon as a function of the position and the tree rings, using micro X-ray fluorescence (mu XRF). A quantification method based in the fundamental parameters approach was evaluated. It was found that silicon concentration increases near the latewood ring zones, showing a periodical behavior, related to seasonal environmental events.
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Villena, M. J., & Araneda, A. A. (2017). Dynamics and stability in retail competition. Math. Comput. Simul., 134, 37–53.
Abstract: Retail competition today can be described by three main features: (i) oligopolistic competition, (ii) multi-store settings, and (iii) the presence of large economies of scale. In these markets, firms usually apply a centralized decisions making process in order to take full advantage of economies of scales, e.g. retail distribution centers. In this paper, we model and analyze the stability and chaos of retail competition considering all these issues. In particular, a dynamic multi-market Cournot Nash equilibrium with global economies and diseconomies of scale model is developed. We confirm the non-intuitive hypothesis that retail multi-store competition is more unstable than traditional small business that cover the same demand. The main sources of stability are the scale parameter, the number of markets, and the number of firms. (C) 2016 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved.
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