Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The process which involves ionic exchange was applied with the use of a Mexican zeolitic mineral (Taxco-Guerrero) to remove Zn, Cd, and Ni from an aqueous solutions. Mineral zeolitic samples in their sodium form were put in contact with Zn(NO3 ) 2 , Cd(NO3 ) 2 and Ni(NO3 ) 2 solutions of 0.01 N for 8 days. After the process of ionic exchange, the metallic elements were determined by Electron Microscopy (EDAX). In previous work, the mineral composition was indentified as a mixuture of clinoptilolite and heulandite of the Mexican zeolitic material.

An introduction to the surprising phenomenon of condensation of matter to temperatures near absolute zero is presented. This phenomenon is based on the quantum foundations of matter, whose main theoretical discoverers were S. Bose and A. Einstein. We begin with a short story of its discovery and continue with an explanation of their important physical properties. Finally, we approach some outstanding aspects of its technological applications, from the results of investigations by the groups headed by Eric Cornell (NIST), Carl Wieman (University of Colorado) and Wolfgang Ketterle (MIT).

We give a review about the problem of thermal convection in fluids, homogeneous porous media and in tilted fractures embedded in porous media with very low permeability. In the later case we show some new results refered to the complex form of the isoterms in the porous media, nearby the fracture, and the existence of convective motion for all Rayleigh number.

After a brief discussion of the early manifestations of Economic Anthropology having characteristics of Victorian Evolutionism in the second half of the Nineteenth Century, this article proceeds to a brief presentation of the two most important founding fathers of the discipline: the Polish-born British anthropologist Bronislaw Malinowsk and the French sociologist-philosopher Marcel Mauss. The middle section discusses encounters between the mentalism that developed among the formalists and the material realism that characterized the substantivists, including the development of a marxist approach and the anthropological study of peasant economies and the world system of Wallerstein. The article ends with a brief mention of a promising new approach: the anthropological study of consumption.

The soliton-like solutions of the Korteweg-deVries equation are reviewed in a historical context as well as their presence in Supersymmetric Quantum Mechanics. The Bianchi diagrams are introduced as a symbolic tool to obtain supersymmetric partners of a given initial Hamiltonian.

By virtue of its nature, plasma is a non linear substance. An important part of Plasma Physics is linked to the electrodynamics of the plasma, where the non linear interaction of waves is essential for studying a whole gamut of non linear processes that occur in plasma. This work describes in introductory form the non-linear electrodynamics of the plasma; and within the framework of the non linear interaction of waves, it also describes some of the most important processes that occur in plasma.

La Real Academia Sueca de Ciencias ha otorgado el premio Nobel de química, versión 1999, al profesor Ahmed H. Zewail, del Instituto de Tecnologíaen Pasadena, California, USA, gracias a sus trabajos pioneros en femtoquímica y a sus estudios sobre los estados de transición de las reacciones químicas mediante la espectroscopia de femtosegundos. Estas investigaciones permitieron demostrar que, mediante una técnica rápida láser, es posible observar cómo se comportan los átomos en una molécula durante una reacción química (Schwarzschild, 1999).

Mexico’s anomaly time series for harvested area, production volume, annual mean yield, and exported and imported volumes of dry bean can be characterized by means of fractal dimension (Dv), estimated through variography. General results suggest those series can be properly modeled as self-affine series. Fractal dimension (Dv) values > 1.5 to 2 indicate presence of short time variation. Whereas Dv values > 1.5 for the dry bean anomaly time series suggest predominance of antipersistent variation; that is to say, all these series are unpredictable unless we involve a fractality parameter in the estimated statistical models so as to predict them.

Previous research confirms that the structure of segments as identified by Parasuraman and Colby (2001), as far as the extent of technology readiness is concerned, is still present within the field of hospital activity of the Andalusian Health Service. In this paper we present an exploratory analysis about which characterization variables of the sample are the best in order to forecast in which segment the individual belongs, there by making the segment much more identifiable. By means of a hierarchical segmentation analysis, we can ascertain that computer knowledge, professional status, number of family members and gender establish the difference when characterizing segments from a social and labour point of view.

The history of economic thought can be characterized as a series of ‘revolutions’. While the success of a revolution in economics depends on the scientific characteristics of the new theory itself, its social acceptance resides in the pre-existence of an orthodox vision inconsistent with reality. In this context, the Keynesian revolution in monetary theory constituted a real revolution, because it had the characteristics to be academically and professionally successful. The very success of any revolution, however, ensures that it will –in turn– become orthodoxy and thus be vulnerable to revolutionary attacks; which in turn give rise to counter-revolution. This was precisely the role played by Monetarism which, following the same principles of liberation of the Keynesian revolution against Classical economics, ignited a counter-revolution by identifying two vulnerable sides in the Keynesian revolution: its inability to prescribe an antidote for inflation, and its dependence on the authority and prestige of senior scholars, thus subjugating young scholars to an outmoded leadership. Even though the Monetarist counterrevolution has served a useful scientific purpose, its success is likely to be transitory, because it has chosen an issue –inflation– that is less relevant socially than unemployment –the issue that gave prestige and longevity to the General Theory. From this perspective, if the essence of economics is seen as a sequence of revolutions and counter-revolutions, a post counter revolution will be required for further development.