Browsing by Author "Munoz, J."

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Electrochemistry of chalcopyrite
    (ELSEVIER SCIENCE BV, 1996) Gomez, C.; Figueroa, M.; Munoz, J.; Blazquez, M.L.; Ballester, A.
    The electrochemical response of a massive chalcopyrite electrode at two different temperatures, 25 degrees C and 68 degrees C, were compared, The electrolyte used in the experiments was an acidic medium (0.4 g . l(-1) (NH4)(2)SO4, 0.5 g . l(-1) MgSO4 . 7H(2)O, 0.2 g . l(-1) K2HPO4 at pH = 2) which is suitable for the growth of the microorganisms involved in the bioleaching process, The chosen temperatures were optimum for the growth of the mesophilic (Thiobacillus ferrooxidans) and thermophilic (Sulfolobus) microorganisms. The experimental results at both temperatures were similar and confirmed that, during the anodic dissolution of chalcopyrite, a passive film is formed on the surface which restricts the oxidation reactions in the medium by diffusional control of the film, The different responses at the temperatures tested were due to the differing physical structure of the complex films of the electrochemically formed sulphides, polysulphides and elemental sulphur.
  • Thumbnail Image
    Item
    Large expansion of oil industry in the Ecuadorian Amazon : biodiversity vulnerability and conservation alternatives
    (2016) Lessmann Escalona, Janeth del Carmen; Fajardo, J.; Munoz, J.; Bonaccorso, E.
  • Thumbnail Image
    Item
    Microstructure analysis on pre-treated apple slices and its effect on water release during air drying
    (ELSEVIER SCI LTD, 2011) Ramirez, C.; Troncoso, E.; Munoz, J.; Aguilera, J. M.
    Microstructural studies have played an important role in the comprehensive understanding of some food phenomena that occur during drying processes. The aim of this work was to study the effect of four pre-treatments (immersion in boiling water, vacuum impregnation, freezing/thawing, and uni-axial compression) on apple microstructure characterized by cell cavities size parameter and how the changes induced by these pre-treatments can affect the water loss rate during air drying. The quantitative structure analysis showed that freezing/thawing and compression pre-treatments caused more damage on the apple structure, yielding larger cell cavities in comparison to vacuum impregnation and immersion in boiling water and control. Apple slices that were frozen/thawed, compressed and immersed in boiling water displayed the higher drying rates and diffusivity coefficients than the vacuum impregnated and control samples. These results allow concluding that disruption of the cell walls can be considered as a factor that affects the drying rate. (C) 2011 Elsevier Ltd. All rights reserved.
  • Thumbnail Image
    Item
    Modelling evaporation processes in soils from the Huasco salt flat basin, Chile
    (2016) Hernandez, M.; Braud, I.; Gironás León, Jorge Alfredo; Suárez Poch, Francisco Ignacio; Munoz, J.