Cálculo de constantes ópticas de películas delgadas de Cu3BiS3 a través del método de Wolfe

Se calculó la obtención de las constantes ópticas usando el método de Wolfe. Dichas contantes: coeficiente de absorción (α), índice de refracción (n) y espesor de una película delgada (d ), son de importancia en el proceso de caracterización óptica del material. Se realizó una comparación del método del Wolfe con el método empleado por R. Swanepoel. Se desarrolló un modelo de programación no lineal con restricciones, de manera que fue posible estimar las constantes ópticas de películas delgadas semiconductoras, a partir únicamente, de datos de transmisión conocidos. Se presentó una solución al modelo de programación no lineal para programación cuadrática. Se demostró la confiabilidad del método propuesto, obteniendo valores de α = 10378.34 cm−1, n = 2.4595, d =989.71 nm y Eg = 1.39 Ev, a través de experimentos numéricos con datos de medidas de transmitancia espectral en películas delgadas de Cu3BiS3.

Climate Change and Transregional Convergence: Carbon Markets in North Amer ica

National policies in North America have not been drafted properly to address the problem of climate change, following the impasse of international negotiations. Facing this scenario, new alternatives emerge with the leadership and participation of new actors. Local governments in North America, especially of British Columbia, Ontario and Quebec, have been developing strategies to face climate change and emissions reduction in parallel to the national efforts and the global governance strategies. These local governments have developed a transregional approach that has resulted in the creation of regional institutions such as the Western Climate Initiative, the Regional Greenhouse GasInitiative and the Midwestern GreenhouseGas Reduction Accord.Their main goal is to establish regional carbon markets to mitigate and adapt to climate change impacts in a cost-effective way. In spite of these efforts, these initiatives have faced the overlapping problem among them and with national and globalstrategies. The goal of this research is to explore how these carbon markets have developed convergence policies. Convergence among these markets is expressed in their offset system and in secondary markets.

Does international trade produce convergence?

In spite of increasing globalization around the world, the effects of international trade on economic growth are not very clear. I consider an endogenous economic growth model in an open economy with the Home Market Effect (HME) and non-homothetic preferences in order to identify some determinants of the different results in this relationship. The model shows how trade between similar countries leads to convergence in economic growth when knowledge spillovers are present, while trade between very asymmetric countries produces divergence and may become trade in a poverty or growth trap. The results for welfare move in the same direction as economic growth since convergence implies increases in welfare for both countries, while divergence leads to increases in welfare for the largest country and the opposite for its commercial partner in the absence of knowledge spillovers. International trade does not implicate greater welfare as is usual in a static context under CES preferences.