Tastets d'economia número 3: la fàbula de les ratetes

Peer-reviewed

Tastets d'economia número 4:el paradigma dels diamants i l'aigua

Peer-reviewed

La defensa del comunal y de los usos colectivos, León (1800-1936): ¿una "economia moral"?

Peer-reviewed

Tastets d'economia número 1: Què és l'economia?

Article d'economia, adreçat a tot tipus de població, en especial estudiants de batxillerat i cicles formatius de la rama administrativa i comercial.

Tastets d'economia número 2: Psicologia i Economia

Article 2 de la sèrie Tastets d'economia, adreçada al target: principiants, estudiants de batxillerat i de cicles formatius, de l'àrea de les ciències socials.

Tastets d'economia número 4:el paradigma dels diamants i l'aigua

Article tastets d'economia número 4, que explica el paradigma dels diamants i l'aigua, adreçat al target de les ciències socials.

Tastets d'economia número 3: la fàbula de les ratetes

Tercer tastet, dels articles d'economia, adreçat al target de les ciències socials.

Com ha de ser l'economia del coneixement?

Catalunya ha apostat per una política de recerca que cada dia aconsegueix bons resultats. Aquesta setmana s'ha fet públic que 14 investigadors que treballen en centres i universitats catalanes han rebut les prestigioses 'Starting Grants de l'European Research Council'. El resultat és destacable si es considera que tot l'Estat espanyol, amb Catalunya, n'ha rebut 29. Catalunya està per sobre de Dinamarca, Àustria, Finlàndia, Noruega, Portugal, Irlanda, Grècia, Hongria, Turquia, Polònia i Eslovàquia

Israel és un bon exemple de l'economia del coneixement

Antoni Castellà, secretari d'Universitats i Recerca, deia que en aquests moments a Israel el 25% del PIB són noves empreses sorgides de l'àmbit científic i que cal fer una aliança amb Israel per seguir el seu camí i veure com podem aprendre d'ells per fer el mateix salt tecnològic en els propers anys

Inserção do conceito de economia atômica no programa de uma disciplina de química orgânica experimental

In this paper, the atom economy concepts are applied in a series of experiments during an experimental organic chemistry class, to implement "green chemistry" in an undergraduate course.

Algas: da economia nos ambientes aquáticos à bioremediação e à química analítica

Algae constitute a large group of many different organisms, essentially aquatic and able to live in all systems giving them sufficient light and humidity. Some algae species have been used in the evaluation or in the bioremediation of aquatic systems. More recently algae have been suggested as interesting tools in the field of analytical chemistry. In this work the most important aspects related to the different uses of algae are presented with a brief discussion.

Determinação eletroquímica da capacidade antioxidante para avaliação do exercício físico

Physical training can adapt or cause injury to skeletal muscles implicating metabolic alterations, which can be detected by biochemical analysis. Apparently the increase in the production of reactive oxygen species (ROS) is involved in both processes. Enzymatic and low molecular weight antioxidants (LMWA) minimize ROS's deleterious action through redox reactions. Cyclic voltammetry (CV) has been suggested as a tool to quantify the antioxidant capacity conferred by LMWA. The use of CV to evaluate the modulation of the antioxidant capacity conferred by LMWA in response to physical exercise is discussed here.

Adsorção de As, Cu, Pb e Cr na avaliação da capacidade de fixação de metais por resíduo de mineradoras de ferro

Two samples of residues from iron mining plants have been investigated for their retention capacity of As, Cu, Cr, and Pb. The sample with the higher content of iron oxides showed the highest capacity to retain metals. The adsorption affinity series changes from Pb>Cu>Cr~As to As>Pb>Cu>Cr or As>Cu>Cr>Pb, depending on the material and the concentration of the initial solution. In the competitive environment, the Pb adsorption decreases and the As, Cu and Cr adsorption increases. Sequential extraction procedures, carried out after adsorption batch experiments, showed that the most important adsorption process occurs in the oxide fraction and that the major part of the absorbed metal is remobilized from exchangeable and oxide fractions.

Estudo da capacidade de complexação e sua relação com algumas variáveis ambientais em cinco represas do Rio Tietê/Brasil

The copper and cadmium complexation properties in natural sediment suspensions of reservoirs of the Tietê River were studied using the solid membrane copper and cadmium ion-selective electrodes. The complexation and the average conditional stability constants were determined under equilibrium conditions at pH=6.00 ± 0.05 in a medium of 1.0 mol L-1 sodium nitrate, using the Scatchard method. The copper and cadmium electrodes presented Nernstian behavior from 1x10-6 to 1x10-3 mol L-1 of total metal concentration. Scatchard graphs suggest two classes of binding sites for both metals. A multivariate study was done to correlate the reservoirs and the variables: complexation properties, size, total organic carbon, volatile acid sulfide, E II and pH.