In this paper we get some lower bounds for the number of critical periods of families of centers which are perturbations of the linear one. We give a method which lets us prove that there are planar polynomial centers of ...

In this paper we get some lower bounds for the number of critical periods of families of centers which are perturbations of the linear one. We give a method which lets us prove that there are planar polynomial centers of ...

The removal of nitrate from a synthetic effluent, 30 mmol dm-3 KNO3 in 0.1 mol dm-3 K2SO4 as supporting electrolyte, is analysed by means of its reduction to ammonia using an undivided electrochemical reactor with a copper ...

The growing use of agrochemicals added to the harm that contaminated containers cause to the environment and to the health of the population, make it necessary to establish a reverse supply chain for the recovery and correct ...

This study simulates the social and economic effects of introducing reverse mortgages in Chile. It uses the 2009 Social Protection Survey and recent simulation methodologies to analyse the monetary gain associated with ...

This work focuses on the production of liquid whey protein concentrates by ultrafi ltration followed by thermal denaturation and homogenization of the ultrafi ltrated concentrate, as well as on the production of ultrafi ...