Caracterización de la reactividad intrínseca de los halobencenos en el modelo conceptual de la teoría de funcionales de la densidad (TFD)

The aim of this paper is to study the family of halobenzenes for characterizing their intrinsic reactivity and in this way to establish a rational order of the intrinsic reactivity of this family of molecules in the electrophilic aromatic substitution. This study was carried out in the framework of Density Functional Theory which provides a global and local index that can be used in the characterization of the reactivity. This index is related to some concept derivatives of experimental chemistry, being a good approach to the characterization of halobenzenes.

Compton scattering tomography for agricultural measurements

This paper presents a new approach in tomographic instrumentation for agriculture based on Compton scattering, which allows for the simultaneous measurements of density and moisture of soil samples. Compton tomography is a technique that can be used to obtain a spatial map of electronic density of samples. Quantitative results can be obtained by using a reconstruction algorithm that takes into account the absorption of incident and scattered radiation. Results show a coefficient of linear correlation better than 0.81, when comparison is made between soil density measurements based on this method and direct transmission tomography. For soil water contents, a coefficient of linear correlation better than 0.79 was found when compared with measurements obtained by time domain reflectrometry (TDR). In addition, a set of Compton scatter images are presented to illustrate the efficacy of this imaging technique, which makes possible improved spatial variability analysis of pre-established planes.

Direct Simulation Monte Carlo Method Applied to Aerothermodynamics

An axisymmetric supersonic flow of rarefied gas past a finite cylinder was calculated applying the direct simulation Monte Carlo method. The drag force, the coefficients of pressure, of skin friction, and of heat transfer, the fields of density, of temperature, and of velocity were calculated as function of the Reynolds number for a fixed Mach number. The variation of the Reynolds number is related to the variation of the Knudsen number, which characterizes the gas rarefaction. The present results show that all quantities in the transition regime (Knudsen number is about the unity) are significantly different from those in the hydrodynamic regime, when the Knudsen number is small.

PREDICTING DIFFUSIVITIES IN DENSE FLUIDS

In this work the Weeks-Chandler-Andersen (WCA) perturbation theory coupled with the Enskog’s solution of the Boltzmann equation for dense hard-sphere fluids is employed for estimating diffusion coefficients in compressed pure liquids and fluids and dense fluid mixtures. The effect of density correction on the estimation of diffusivities is analyzed using the Carnahan-Starling pair correlation function and the correlation of Speedy and Harris which have been proposed as models of self-diffusion coefficient of hard-sphere fluids. The approach presented here is based on the smooth hard-sphere theory without any binary adjustable parameters and can be readily used for estimating diffusivities in multicomponent fluid mixtures. It is shown that the correlated and the predicted diffusivities are in good agreement with the experimental data and much better than estimates of Wilke-Chang equation.

Did ISI fail and is neoliberalism the answer for Latin America? Re-assessing common wisdom regarding economic policies in the region

The second phase of Import Substituting Industrialization, commonly known as ISI2, involved the move in Latin America to "heavy" industrialization, from around 1950-80. This period of economic history has been reviled on both the Left and the Right as being one of either heightened dependency or one demonstrating the clear failure of state intervention in the economy. In this research note, a basic statistical analysis is used to back up other descriptive claims that the ISI2 period was rather one of mixed success, with macroeconomic volatility accompanying great progress in GDP and manufacturing growth. In a sense, the ISI2 period succeeded in industrializing the large economies of the period, and contrasts favorably with the record of the succeeding paradigm of neoliberalism. This research note seeks to raise questions about the way we look at the historical period of ISI2, and suggests that a more open-minded perspective could lead to a more effective and sustainable political economy paradigm for the region in the future.

Resuming growth in Latin America: short and long term policies

The authors of this paper assert that the paralysis of the state generated by the crises of the 1970s and 1980s deprived the economies of the region of an important lever to resume and sustain growth. They thus maintain that to overcome stagnation it will be necessary to reconstruct the state's capacity to implement pro-growth policies. Following Keynes and Kalecki's ideas, but also classical development economists, the authors argue, first, that short-term macroeconomic policies, to reduce unemployment and to increase the degree of capacity utilization, should be used to promote the generation of profits to firms and to wake up entrepreneurs' animal spirits. Short-term expansionary policies should be coupled with measures to improve competitiveness and avoid balance of payments problems. They also claim that alternatives to the liberal programme will fail unless a pro-growth strategy is adopted which includes both short- and long-term policies. They thus propose that long-term policies must complete the package, signaling: a) sustained increases of effective demand in the future; and b) investment priorities to ensure that capacities will be created in strategic sectors and branches of the economy.

Subdesenvolvimento sustentável? Velhas e novas contradições na periferia do capitalismo

This paper addresses the concept of sustainable development and, more particularly, its applicability in underdeveloped economies when analyzing reciprocal effects between economic organization and environmental issues. It also addresses the relationships between development and underdevelopment, from an ecological economics' approach, and its theoretical implications regarding the concept of sustainable development. We conclude that the specificities of Latin American economies, when compared to those economies of developed countries, also entail, beyond economical disparities, the existence of strong antagonisms from an environmental standpoint, which are recurrently ignored by most of the interpretations concerning sustainable development.