La garnierita, un compuesto formado por las fases minerales de talco y serpertina, es rico en Ni. Este compuesto fue tratado con diferentes concentraciones de hidróxido de amonio: 0, 2 y 4 M con fin de aumentar el área específica del sólido. Luego, el mineral tratado con la base fue impregnado con una solución de Mo (15% p/p como MoO3). Estos sólidos fueron caracterizados por las técnicas fisicoquímicas tales como: DRX, FT-IR, medidas de área específica BET y análisis químico. Los sólidos impregnados con Mo fueron probados en la reacción de hidrodesulfuración (HDS) de tiofeno; los resultados encontrados determinaron que existe una relación entre la conversión de la reacción de HDS y el área específica de estos sólidos.

Garnierite, it is a compound forming for talc and serpentine mineral phases, it is rich in Ni. This compound was treated with different ammonium hydroxide concentrations: 0, 2 and 4M for increasing the specific area of these solids. Then, the base treated mineral was impregnated with a Mo solution (15% w/w as MoO3). These solids were characterized by physicchemical technique different such as: X-ray diffraction, FT-IR, BET specific area and chemical analysis. Mo impregnated solids were tested in the thiophene hydrodesulfurization reaction; Results showed a relationship between the HDS reaction and the specific area of these solids.

A hydrocalumite-type material (HC) was synthesized by the co-precipitation method, mixing Ca and Al nitrate solutions in a NaOH solution (pH ≅ 11). This solid was characterized by using different physico-chemical techniques such as: Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), temperature programmed reduction (TPR) and BET surface area measurements. Then, a portion of as-synthesized solid was calcined at 420 ºC (HC 420). Both calcined and pristine solids were impregnated with Mo (15% w/w as MoO3). Ni or Co was also impregnated on Mo/HC or Mo/HC 420 in 1(Co or Ni):3 (Mo) atomic ratios to get catalytic precursors. These solids were also characterized by the above mentioned techniques. Catalytic precursors were tested in the thiophene hydrodesulfuration reaction at 280 ºC and atmospheric pressure. Cobalt promoted catalysts were more active than those promoted with Ni. However, thiophene conversions were lower than that of a conventional CoMo/γ-Al2O3 catalyst.

La teoría del capital social es un enfoque muy innovador orientado a entender aspectos esenciales de los sistemas democráticos modernos, como el funcionamiento de las instituciones que dirigen las reglas de juego en una sociedad. Esta teoría es iniciada por el investigador norteamericano Robert D. Putnam, quien sostiene que una institución con alto desempeño efectivo depende en gran medida de las tradiciones cívicas implícitas en la cultura que caracteriza la sociedad en la cual opera, ya que a través de las tradiciones cívicas las personas e instituciones desarrollan mecanismos y recursos que afectan de forma determinante el cumplimiento de las reglas de juego sociales. Nuestro interés apunta a estudiar los planteamientos entorno a la noción del capital social desarrollado por Putnam, examinando sus logros, sus alcances, sus limitaciones y dificultades. Al mismo tiempo, nuestro interés se extendido a señalar algunas pistas teóricas que podrían enriquecer las investigaciones de esta importante concepción.

The theory of social capital is an innovating approach directed to understand the essential aspects of modern democratic systems as the functioning of the institutions responsible of the rules of the game in a society. This theory was initiated by the North American researches, Robert D. Putnam, who argues that an institution with highly effective performance depends mainly on the civic traditions in the culture that characterizes the society in which it operates, since it is through civic traditions that peoples and institutions develop mechanisms and resources which affect in a determining way the fulfillment of the rules of social games. We are interested in studying the issues concerning Putnam’s notion of social capital, analyzing its achievements, scope constraints and difficulties. At the same time, we will suggest some theoretical considerations that could enrich research in this important topic.