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  The study of the corrosion resistance of anodized on aluminum alloy (AA6063) in sulfuric acid to different times: 30, 45 and 60 min. was performed using electrochemical impedance spectroscopy (EIS) and the acid salt spray test (ASTM B287). The EIS’data and its correlation with the most appropriate equivalent circuits allowed to determine the parameters associated with the porous layer and the oxide layer protective barrier formed on the aluminum surface under study. Exposure of the samples anodized for a 250h salt spray acid allowed to observe changes in their mass. From the results obtained by EIS and the mass losses of the anodized samples was established that the anodized film of 45 minutes showed higher corrosion resistance compared to that obtained at 60 and 30 min, respectively. 

 The study of the corrosion resistance of anodized on aluminum alloy (AA6063) in sulfuric acid to different times: 30, 45 and 60 min. was performed using electrochemical impedance spectroscopy (EIS) and the acid salt spray test (ASTM B287). The EIS’data and its correlation with the most appropriate equivalent circuits allowed to determine the parameters associated with the porous layer and the oxide layer protective barrier formed on the aluminum surface under study. Exposure of the samples anodized for a 250h salt spray acid allowed to observe changes in their mass. From the results obtained by EIS and the mass losses of the anodized samples was established that the anodized film of 45 minutes showed higher corrosion resistance compared to that obtained at 60 and 30 min, respectively. 

The following article presents the results of performance evaluation systems anticorrosive paint for use in the national industry, epoxy systems, using the accelerated salt spray (fog) test(ASTM B 117). The experiment was carried out for a period of exposure 125 days or 3000hours. The paint systems were tested applied on steel plates with different types of surfacepreparation: manual, mechanical and sandblasted (white, dry and wet). The evaluation ofthe samples tested were made according to the criteria of the relevant standards: Grade Oxidation, Blistering and Deterioration in Incision. The degree of deterioration in the incision showed that the epoxy systems with sandblasting surface preparation show a greater resistance to deterioration in the incision, compared to those of surface preparation manual cleaning and mechanical cleaning.

El estudio de la resistencia a la corrosión del anodizado de una aleación de aluminio (AA6063) en ácido sulfúrico a diferentes tiempos de anodizado: 30, 45 y 60 min. se realizó usando la espectroscopia de impedancia electroquímica (EIE) y el ensayo de niebla salina ácida. (ASTM B287). Los datos obtenidos por EIE y su correlación con los circuitos equivalentes más apropiados permitieron determinar los parámetros asociados a la capa porosa y a la capa barrera del óxido protector formado sobre la superficie del aluminio en estudio. La exposición de las muestras anodizadas durante 250h a una niebla salina ácida permitió observar variaciones en su masa. De los resultados obtenidos por EIE y las pérdidas de masa de las muestras anodizadas se estableció que la película de anodizado de 45 minutos mostró una mayor resistencia a la corrosión en comparación con la obtenida a 60 ...

En el siguiente artículo se presenta los resultados obtenidos de 1a evaluación del comportamiento anticorrosivo de sistemas de pinturas de uso en la industria nacional, sistemas epóxicos; utilizando el ensayo acelerado de niebla salina (ASTM B 117). El ensayo se realizó por un período de exposición de 125 días ó 3000 horas. Los sistemas de pinturas ensayados fueron aplicados sobre placas de acero con diferentes tipos de preparación de superficie: manual, mecánico y arenado (al blanco, en seco y en húmedo). La evaluación de las muestras ensayadas se realizó según los criterios de las normas correspondientes: Grado de Oxidación, Ampollamiento y Deterioro en la Incisión. El grado de deterioro en la incisión permitió observar que los sistemas epóxicos con preparación de superficie de arenado muestran una mayor resistencia al deterioro en la incisión, comparados con los d...

In order to use native plant extracts in medicinal, cosmetic, anticorrosive and other applications; the objective of these work was to evaluate the antioxidant activity, as well as the content of flavonoids and total phenolic compounds of the ethanolic and hydroalcoholic extracts of the leaves of Buddleja inkana (quisuar), Oreocallis grandiflora (cucharilla) and Chuquiraga spinose (huamanpinta). The measurement of antioxidant activity: FRAP, DPPH and ABTS·+, as well as the content of flavonoids and total phenolic compounds, was carried out by the microplate reader method. The results when evaluating the antioxidant activity of ethanolic and hydroalcoholic solutions at 75 and 50 % (v/v) in ethanol extracts showed that the extracts of Oreocallis grandiflora showed a higher antioxidant activity than Buddleja inkana and Chuquiraga spinosa, and that the hydroalcoholic extracts at 75 % (v/v) ...

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The group-contribution method of UNIFAC have been evaluated to predict phase equilibria for the n-butyl acetate-cyclohexane system at low pressures. The results show that this method predicts satisfactorily the studied system. The experimental results were obtained in a boiling point apparatus at low pressures, giving in this way experimental data from which we have scarce information.

El método de contribución de grupos de UNIFAC ha sido evaluado para predecir el equilibrio de fases del sistema acetato de n-butilo-ciclohexano a bajas presiones. Los resultados muestran que el método predice satisfactoriamente los datos de equilibrio líquido-vapor del sistema estudiado. Los resultados experimentales fueron obtenidos en un dispositivo de medición de puntos de ebullición a baja presión, aportando de este modo la data experimental de un sistema del que se dispone poca información.

In the present study, the ethanolic and aqueous extracts of the leaves of Annona muricata L. were obtained. The extraction conditions were established from the total soluble solids content and the corrosion inhibiting effect obtained from the polarization resistance, Rp (Ω • cm2), of the steel 1008, in a 1 Molar solution of HCl in the absence and presence of the inhibitor extract. The extracts with greater corrosion inhibiting effect were characterized by phytochemical screening, quantification of total phenols, alkaloids, flavonoids and antioxidant activity (DPPH). The ethanolic extract had a 1.5 times greater corrosion inhibiting effect than the aqueous extract. The phytochemical screening established that both extracts contain a wide variety of secondary metabolites, such as phenols, alkaloids, flavonoids, tannins and sesquiterpenoid lactones. Among the studied extracts, the ethano...