Enfoque UTE

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Authors: José Antonio Morales Castro

This work evaluated the business risk change of 20 companies included on the sustainable index of the Mexican Stock Exchange (BMV). The unlevered beta coefficient was used for this analysis. Two periods were compared: the one before, and the one after including the companies on the index. For each of the 20 companies it was used financial information, stocks closing prices and the stock market index value, over a period of 234 weeks. Then, considering the two periods, the statistical difference between the unlevered beta coefficient averages was calculated. Finally, a hypothesis proof was made to evaluate the business risk change. It was found that for 12 out of the 20 companies, the unlevered beta coefficient suffered a reduction. The findings suggest that it is not enough for the companies to certify as sustainable in order to reduce its business risk.

54 - 69

Authors: Elena Beltrán, María Belén Jácome, Edison Matute

The aim of this study was to obtain a flavored green tea with organic rose petals "Vitality" from Nevado Ecuador. Green tea, purchased from a private company, it was subjected to analysis to verify compliance with the requirements of standard INEN 2381: 2005. The Characterization of fresh rose petals was to made and for the dehydration was used two temperatures and two geometries. Analysis of total polyphenol content (Folin-Ciocalteu) and antioxidant capacity (TEACmethod) were performed. The dried petals, with a higher content of polyphenols and antioxidant capacity, were used in the preparation to flavored tea. Three formulations with different amounts of dried rose petals (10, 17.5 and 25%) were tested sensorially by 100 judges to determine the aroma rose in the tea. The final product was analyzed to determine compliance of the requirements of the standard INEN of the tea. Finally acceptability and purchase intention of the product is evaluated. The values of content total polyphenol in the extracts of rose petals were superior to fruits such as blackberries, and strawberries.

89 - 98

Authors: Idalberto Tamayo Ávila, Ivanna Guamán Tumaille, Yandi Fernández Ochoa, Nilo Ortega Soliz

In this paper the presence of electric charge in two insulation of cross-linked polyethylene (XLPE) in medium voltage cables was compared using the technique of Thermally Stimulated Depolarization Currents (TSDC). Antioxidant in solid form was added to one of the insulation, and in liquid form to the other. By analyzing the TSDC measures we verified that the use of liquid antioxidant is better because the solid antioxidant creates defects that act as centers for trapping the space charge. In these centers the ionized charge, by the combined effect of temperature and electric field, is accumulated in the insulation, in addition to the charge injected from the semiconductor electrodes by the effect of high fields.