Browsing by Author "Herrera, M."

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    Interactive System for Language and Communication Stimulation Directed to Young Children
    (IEEE, 2019) Vásquez, C.; Jiménez, J.; Guevara, M.; Cortés Peña, Pamela Alejandra; Herrera, M.; Pittaluga, E.; Pino, E. J.; Guevara, P.; Peña Harris, Maria Caridad
    We present an Interactive System for Language and Communication Stimulation (ISLACS) directed to young children. The system is a technological educational application intended to stimulate learning abilities, developed as a native mobile application for devices with Android operating system. It is specially designed for children between 2 and 4 years of age, to stimulate language, contingency and attention, through cognitive tasks in the form of interactive mini-games. The activities teach the association between images with the corresponding infrequently used spoken words, and images of letters with the corresponding sounds (i.e. phonemes). The mini-games are based on multimedia resources, mainly videos of an educator, real objects and animals. The software evaluates progress by measuring interaction parameters such as correct answers and response time and has an algorithm to randomize the trials across children. The application is tested in 314 2-4 year-old children. Each child played a minimum of 8 sessions every other day, each one presenting 6 words and 4 letters, and testing for 3 words and 2 letters. Results showed that ISLACS is an attractive game for young children, which significantly succeeded to teach children the sounds of the letters and a repertory of nearly 48 infrequent words in Spanish, in a brief intervention.
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    Postoperative adjuvant treatment for gastric cancer improves long-tenn survival after curative resection and D2 lymphadenectomy. Results from a Latin American Center
    (2016) Norero Muñoz, Enrique; Bustos Carrasco, Marisa Orietta; Herrera, M.; Cerda, Jaime; González, P.; Ceroni Villanelo, Marco; Martínez Belmar, Cristian Antonio; Briceño, Eduardo; Rojas Romero, Hernán Humberto; Cartes, R.; López, V.; Hidalgo, V.; Báez, S.; Caracci, M.; Viñuela, E.; Díaz, A.
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    Role of biosolids on hydrophobic properties of sulfide ores
    (2011) Reyes-Bozo, L.; Herrera-Urbina, R.; Escudey, M.; Godoy-Faundez, A.; Saez-Navarrete, C.; Herrera, M.; Ginocchio, R.
    The effect of biosolids on hydrophobic properties of sulfides ores was studied. The principal components of biosolids are humic substances, mainly humic acid, and phosphorus compounds. The feasibility of using biosolids as collector for copper sulfide ores (CSO) was performed through zetapotential measurements, FT-IR analysis and film flotation tests. Addition of different dosages of biosolids, a commercial humic acid (CHA), and an industrial collector makes the zeta potential of a copper sulfide ore more electronegative in the entire pH range studied. FT-IR spectra show that CHA can interact with mineral surfaces through outer-sphere linkages. CHA can adsorb physically on chalcopyrite and pyrite through hydrogen bonds or Van der Waals forces. Orthophosphate, however, adsorbs chemically on the surfaces of these mineralogical species through inner-sphere linkages. Therefore, biosolids that contains both humic acid and phosphorus compounds can interact with CSO surfaces through a complex mechanism involving both inner and outer-sphere linkages. Further, film flotation tests - in accordance with zeta potential results - show that biosolids adsorb on the surface of the sulfide ores investigated, changing their hydrophobicity. Biosolids show greater affinity for pyrite while commercial humic acid show similar behavior to industrial collectors. Therefore, both biosolids and humic acids can change the hydrophobic properties of sulfide ores and can be used as collectors in froth flotation processes. Further research will be needed in order to scale-up laboratory results to industrial mineral operations. (C) 2011 Elsevier B.V. All rights reserved.
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    Understanding water disputes in Chile with text and data mining tools
    (2019) Herrera, M.; Candia, C.; Rivera, D.; Aitken, D.; Brieba, Daniel; Boettiger, C.; Donoso H., Guillermo; Godoy Faúndez, A.