Examinando por Autor "Rivas, J."

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    Grape crushing and traditional wine presses in Chile and Argentina (1550-1850)
    (Universidad de Concepción, 2011) Lacoste, P.; Aranda, M.; Matamala, J.; Premat, E.; Quinteros, K.; Soto, N.; Gaete, J.; Rivas, J.; Solar, M.
    The wine press is a vessel where grapes are crushed and where the process of the elaboration of wine begins. It is relevant not only for its industrial and economic significance but also for its social and cultural implications. This article contributes to the understanding of the socioeconomic history of the region under study while at the same time serving as a contribution to the development of the recognition of the value of the traditional methods of the wine industry that once again are being used for the elaboration of Premium wines as well as for wine tourism.
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    Sorption of apolar pesticides by units of benzoic acid propyl ester in cyclic phosphazene
    (Sociedad Chilena de Quimica, 2017) Rivas, J.; Valenzuela, M.L.
    The effects of temperature, pH and agitation time (equilibrium) on the adsorption process of different pesticides on N3P3(OC6H4COOCH2CH2CH3)6 was studied. With optimal conditions experimental, the adsorption isotherms have been realized with through Langmuir and Freundlich models. Pesticides are compounds used mainly in agriculture to control various species (plants, insects, worms, fungi). Due to their physicochemical properties, they can remain for a long time in the application sites, bioaccumulating and moving between environmental compartments which generate various environmental problems. The results obtained showed a physisorption mechanism for the fve pesticides studied, with higher sorption for: azinphos methyl (93,5 mg kg-1), carbaryl (290.5 mg kg-1) and carbofuran (580.5 mg kg-1) at 20 ° C, according to the models used. © 2018 Sociedad Chilena de Quimica. All rights reserved.
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    Ítem
    Subcritical water extraction of essential oils and plant oils
    (Elsevier, 2023-12) Díaz-Reinoso, B.; Rivas, S.; Rivas, J.; Domínguez, H.
    Subcritical water extraction is a green technology with interesting advantages in relation to the possibility of processing fresh raw materials to sustainably obtain natural valuable products. The potential of this technology for the aqueous extraction of lipophilic fractions from plant biomass is well known and has recently attracted renewed interest. This review presents an update of the advances on the extraction of two valuable types of lipophilic products, essential oils and vegetal lipids from various plant biomasses. It also emphasizes the effect of process variables as particle size, time, liquid to solid ratio, pressure and temperature as well as the operation tunability to select optimal conditions for different solutes. The optimal operation conditions play a key role to efficiently recover these natural products with potential applications in cosmetic, food, agricultural and pharmaceutical/medical industries.