Potentiodynamic behaviour of CuA1Ag alloys in NaOH: a comparative study related to the pure metals electrochemistry

The mechanism of electrochemical oxidation of surface reformed CuA1Ag alloys having different composition of heat treatment, in 0.5 M NaOH was studied by means of cyclic polarization, constant potential electrolysis, ICP, AA, SEM and EDX. The surface reformation consisted of a repetitive triangular potential sweep (RTPS) between H 2 and O 2 evolution at 100 mV s -1 in the working solution itself, performed in order to increase the electrode roughness and obtain a quasi-stationary I/E profile in which the potentiodynamic behaviour of copper and silver was clearly revealed. The alloys suffer aluminum dealloying after such an RTPS. The quasi-stationary cyclic polarization curve exhibits a multiplicity of current peaks which have been related to the electrochemical reactions involving the pure alloying elements. Complex potential perturbation programmes in regions having different anodic and cathodic limits allowed the study of the mechanism of the electrochemical oxidation of the surface reformed alloys and the compare with that corresponding to the pure metals. The basic differences between the electro-oxidation processes of the surface reformed CuA1Ag alloys with respect to those established for the high purity alloying metals are the splitting of the peaks corresponding to the formation of the Cu(I) and Ag(I) species. © 1991.

Imaginária retabular colonial em São Paulo: estudos iconográficos

Pós-graduação em Artes - IA

Saúde Mental e Morte: subsídios para implantação dos Cuidados Paliativos na Atenção Básica

The objective of this work was, from a bibliographical survey, to discuss the relationship between the subjects “Mental Health” and “Death”, in order to analyze possible contributions of the Psychiatric Reformation tied with the sphere of Palliative Cares. The characterization of madness as a social problem is related to the development of the capitalist mode of production. Unable to fulfill the requirements imposed by capital, insane persons are excluded from society and locked in psychiatric hospitals in order to be treated. In the same way, death is incompatible with the capitalist principles of accumulation of goods. Dying people are then transferred to the hospital in order to hide their invalidity, non-production and felt inexistence of wealth. Some principles for care in mental health that could be shared in the palliative cares are: deinstitutionalization; organization of assistance in a network; psychosocial assistance; interdisciplinarity and construction of the autonomy of family members and users. In this sense, some challenges are distinguished, between them, professional training.

Diagnóstico do uso de técnicas de calagem e aubação dos assentamentos rurais do estado de São Paulo: estudo de caso

In the context of the project “Development and qualification of agriculturists in the use of techniques for correction of theground in agricultural assentament”, the identification of the use of agricultural techniques becomes necessary as an important tool for decision taking, mainly in regards to the public politics of Assistance Technique and Agricultural Extension (ATER). In such a way, the present study it had for objectiveto diagnosis the use of limeand fertilization techniques in these agricultural assentamentin order to identify possible public politics ATER. Of the total of boarded families, 79.89% had answered to the questionnaire elaborated for this diagnosis. The field research was carried throughapplication of questionnaire elaborated for this study and the analysis of the results divided in profile of the beneficiaries, knowledge of techniques of ground handling and agricultural use of the areas of the Projects of Assentamentfor the beneficiaries. It was concluded that even so the great majority of the beneficiaries agricultural area and farmers to be declared diligent of this information are not in coherence with the one of knowledge of the type of ground, therefore, this type of understanding of the landscape is primordial for the taking of decision with regard to the agricultural use of the ground, moreover, the access to the knowledge and use of the techniques of limeand fertilization comes diminishing in the agricultural assentamentunder validity of II National Plan of the Agrarian Reformation, what it enters in total discord with the premises of the same. It fits here to detach the importance of public politics ATERdirected these beneficiaries of the Agrarian Reformation, mainly with regard to the ground handling.