Fidel Aroche Reyes

La estructura económica del (sub)desarrollo y el equilibrio general o ¿qué ocurrió con la teoría del desarrollo y con las estructuras económicas?

Formerly the concept of economic development involved transforming the productive structures in order to employ the population in higher productivity activities, so that welfare improved. Development implied that economic systems followed development paths (not always in equilibrium) in order to reach more desirable welfare results: Equilibrium was not the main target. More recently, economic strategies emphasize reaching growth within equilibrium paths, thus, preserving economic structures. The latter vision yields incompatible results with the former. This paper revises some issues concerning structural change versus equilibrium targets as a means to reach development.

Mass Transfer Kinetics in the Desulphurisation of Pig Iron with CaO and CaC2

This paper discusses the effect of the main parameters that affect the desulphurization reaction efficiency. The study was conducted by evaluating different reaction sites within the metal, the slag and the reducing agents. It was possible to establish a mass transfer model that determines the amounts of the reducing agents needed to maintain adequate sulphur levels in the pig iron. Industrial trials showed the accuracy of our model.

Rate of Reduction of Chromium Oxides in a Slag by FeSi and FeMgSi Ferroalloys

The rate of reduction of chromium oxides in a stainless steel slag was studied in stagnant slag / metal melts at 1600 °C. The experimental results show that the magnesium contained in a FeMgSi ferroalloy has a reduction potential comparable to that of the silicon in a FeSi ferroalloy. On the other hand, it was confirmed that the rate limiting step in the reduction of the chromium oxides is the transport of chromium from the bulk of the slag to the slag / metal interface. The mass transfer coefficients for the reduction of chromium were estimated and are in good agreement with previously reported values.

Modelling economic structures from a qualitative input–output perspective: Greece in 2005 and 2010

Sectors in economic systems are interdependent because they trade goods that consuming sectors use as inputs; the relative values of those supply and demand links define economic structures. Industries play different roles depending on the relative number of connections they maintain with one another and on whether those links are preferably demands or supplies. On this regards, we extend a stochastic social structural model into the economic context. Further, we apply it to recent Greek data, analysing the role of different technological intensity sectors. We show that our results help to explain some structural features of this economy.

Kinetic Description of the Mass Transfer in Ladle Metallurgy Operations

In this work a kinetic model which describes the main refining reactions in a ladle furnace is depicted. The main difference between this work and other models previously reported relies on a formal quantification of the multi-component diffusion kinetics expressed as an analytical solution. Results from this model reproduce/predict adequately the chemical steps involved in an integrated steel shop.