Artur Gonçalves

Ionic conduction and thermal properties of poly(ethylene oxide) - Er (CF3SO3)3 films

Measurements of electrical conductivity and thermal behaviour have been carried out on polymer electrolyte films obtained by the addition of erbium triflate to poly(ethylene oxide), PEO. Homogeneous electrolyte samples were prepared by using solvent casting and hot-pressing techniques to produce films with a composition defined by the general formula (EO)nEr(CF3SO3)3, where n lies between 3 and 150.This electrolyte system was found to behave in a manner broadly similar to other trivalent salt containing polymer electrolytes, however, in contrast to previously studied lanthanide systems, a salt - polymer complex crystallized after prolonged annealing of salt rich compositions at room temperature.

Away from silicon era: the paper electronics

Today there is a strong interest in the scientific and industrial community concerning the use of biopolymers for electronic applications, mainly driven by low-cost and disposable applications. Adding to this interest, we must recognize the importance of the wireless auto sustained and low energy consumption electronics dream. This dream can be fulfilled by cellulose paper, the lightest and the cheapest known substrate material, as well as the Earths major biopolymer and of tremendous global economic importance. The recent developments of oxide thin film transistors and in particular the production of paper transistors at room temperature had contributed, as a first step, for the development of disposable, low cost and flexible electronic devices. To fulfil the wireless demand, it is necessary to prove the concept of self powered devices. In the case of paper electronics, this implies demonstrating the idea of self regenerated thin film paper batteries and its integration with other electronic components. Here we demonstrate this possibility by actuating the gate of paper transistors by paper batteries. We found that when a sheet of cellulose paper is covered in both faces with thin layers of opposite electrochemical potential materials, a voltage appears between both electrodes -paper battery, which is also self-regenerated. The value of the potential depends upon the materials used for anode and cathode. An open circuit voltage of 0.5V and a short-circuit current density of 1μA/cm2 were obtained in the simplest structure produced (Cu/paper/Al). For actuating the gate of the paper transistor, seven paper batteries were integrated in the same substrate in series, supplying a voltage of 3.4V. This allows proper ON/OFF control of the paper transistor. Apart from that transparent conductive oxides can be also used as cathode/anode materials allowing so the production of thin film batteries with transparent electrodes compatible with flexible, invisible, self powered and wireless electronics.

P02-123 Consumption of drugs in the adolescence

It is a consummate fact that the youths occupy, during the adolescence most of the day in the school, being that many prominent behaviours for the health are initiated in this phase of the life. It is for that fundamental that the schools be health promoters spaces.Objectives : to know the age of initiation to the consumption of alcoholic beverages, tobacco and illicit drugs in this sample; to calculate the prevalence rate of these consumption; to identify priority areas to approach in the Health Education process. This is a descriptive and cross-sectional study, that is going to identify behaviours of risk for the health of High School students of Douro Region. The sample is constituted by 466 students of seven schools. The data were collected through a questionnaire on line, of Janeiro to March of 2007, disposed in the site http://jovemsaudavel.com.sapo.pt , designed for the effect. In the data treatment we utilize the statistical descriptive and the qui-square test. The ages average of initiation to the consumption of alcoholic beverages, tobacco and illicit drugs is 12,5, 12,3 and 13,6 years, whereas the prevalences of these consumption are 38,9%, 16,9% and 6,0%, respectively. Highlights-itself the sporadic consumption of alcoholic beverages (28,4%), the abusive consumption of tobacco (9,4%) and of illicit drugs (1,8%). The boys swallow beverages and smoke with bigger frequency than the girls ((c 2 : p = 0,006 and 0,001). They had intercourse relations already 27,7% of the students of this sample, of the which 11,9% did not use protection.